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1
Lee, Jian-Cheng. "Structure et deformation active d'un orogene : taiwan." Paris 6, 1994. http://www.theses.fr/1994PA066395.
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Afin d'examiner et de caracteriser les structures et les deformations actuelles dans la chaine de taiwan, nous avons effectue plusieurs types d'analyses a differentes echelles en trois volets: d'abord, l'analyse d'imagerie: cette etude, effectuee a l'echelle de l'ile de taiwan, permet de synthetiser les caracteristiques morpho-structurales de la chaine et fournit ainsi un cadre aux etudes plus specifiques. Plusieurs types de structures ont ete reconnus, incluant des structures obliques dans les differentes regions, dont certaines inconnues auparavant. L'analyse de frequences directionnelles met en evidence des differences caracteristiques pour les directions dominantes dans les differentes regions. Une carte morphoneotectonique de taiwan a ete realisee en collaboration. Elle represente ainsi une base multisource de donnees numeriques, qui permet les comparaisons avec les autres analyses plus detaillees. Ensuite, l'analyse des accidents majeurs de la chaine a porte sur les trois principaux exemples: 1) les fronts de chevauchement occidentaux, representant les structures et les deformations recentes dans un systeme de plis et de chevauchements a vergence ouest, dans l'ouest de taiwan ; l'analyse des paleocontraintes et l'etude des relations entre erosion, sedimentation et tectonique dans les fronts de chevauchement occidentaux a ete effectuee afin de caracteriser les structures et les deformations plio-quaternaires (en particulier pleistocenes) et de souligner les differences entre le centre et le sud de taiwan. 2) la faille de lishan, situee dans la chaine, representant un accident majeur qui a subi des deformations complexes des le debut de l'orogenese de taiwan ; nous avons reconstruit des profils a partir d'examens de terrain dans la region de la faille de lishan. L'analyse tectonique dans cette region a permis de mettre en evidence les caracteristiques structurales et l'evolution geodynamique de la faille de lishan. 3) la vallee longitudinale, constituant une frontiere principale entre les plaques, et qui absorbe la deformation dans la region de taiwan. Dans la partie meridionale de la vallee longitudinale, la deformation actuelle est essentiellement absorbee sur un segment de faille active, comme le montre l'analyse des donnees geodesiques. Cette deformation est caracterisee par les deplacements de failles, d'ailleurs confirmees par l'examen geologique de terrain. Enfin, l'analyse des mecanismes regionaux a pu etre effectuee pour toute l'ile: il s'agit d'un essai de synthese sur les contraintes tectoniques dans la region de taiwan, afin de preciser le cadre geodynamique de la collision. A partir de l'etablissement d'une base de donnees tectoniques et de la reconstruction des trajectoires de contraintes, nous avons pu caracteriser les mecanismes regionaux de deformation quaternaire actuelle et l'evolution geodynamique en termes de paleocontraintes plio-quaternaires a taiwan
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Whitfield, Carl A. "Modelling spontaneous motion and deformation of active droplets." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/11704/.
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This thesis investigates symmetry breaking phenomena and motile steady states in droplets driven by stresses generated by active (out-of-equilibrium) liquid crystals. First, we show that in a fluid droplet with active polar liquid crystal an asymmetric polarisation field is sufficient to drive steady state motility. We are able to approximate the forces and flows generated in such a system analytically, and show how the force distribution on the droplet interface is characteristic of this motion. Second, we consider the case of a passive fluid droplet immersed in an active liquid crystal. Here we see that strong anchoring at the droplet interface can create an asymmetric equilibrium configuration, and thus any active stress can drive propulsion of the drop. Third we analytically perform linear stability analysis calculations on two kinds of active droplet to determine how active stresses can make these systems unstable to symmetry breaking events. Finally, we produce 2D simulations of these systems so that we can find the resulting steady states of these systems. We observe a rich phase space of behaviour, with steady state flows in the droplets that result in motion, symmetric deformations and rotation.
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Morewood, Nigel Clifford. "Segment boundaries in active normal fault systems." Thesis, Birkbeck (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249514.
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Koberg, Henrik. "Turbulence control for drag reduction with active wall deformation." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486911.
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Ecological and economical considerations motivate the search for ways to reduce the skin friction drag in turbulent flows. Several numerical studies have shown that wall shear stress can be lowered at low Reynolds numbers by applying a small amount of wall transpiration. In this study it is investigated how another type of actuation, active wall deformation, could be used to yield a similar effect. . Ã??Ã?? First. discrete time-dependent wall deformation is studied in laminar flow. Lacking background turbulence, the baseflow allows clear identification of the flow perturbation. The analysis reveals that a downward moving actuator is surrounded by a region of negative wall-normal velocity and vice versa. Comparably less intuitive are the vorticity fields which often display complicated structures. A similar, subsequent study in turbulent flow shows that, indeed, active wall deformation can restruckJre wall turbulence. Seised on thesA findings, a series of experiments were conducted on opposition control. This scheme . aims at opposing the velocity sensed away from the wall by imposing velocity of opposite direction at the wall. By locally deforming the wall accordingly, skin friction reductions of up to 15% are observed. Parameters critical to the performance of the control scheme, such as actuation scales and deformation limiters, are identified and analysed. As Reynolds number and actuation scales are much smaller than in practical applications, the results are of limited applicability but encouraging for prospective drag reduction at higher Reynolds numbers. In a separate study a novel control method based on non-linear global stabilisation of the perturbed Navier-Stokes equations was tested. Using body forcing over the entire domain as actuation. the flow
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Gregory, Laura C. "Active faulting and deformation of the Mongolian Altay Mountains." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:4bbed5b2-4597-4faa-b08c-c182d148c152.
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In this thesis, I use multiple techniques to investigate the active faulting and deformation of the Altay Mountains, Western Mongolia. The Altay are an intracontinental transpressional mountain range, which are deforming in the far-field of the India-Asia collision. An anastomosing network of dextral faults strikes NNW-SSE, and accommodates NE-SW oriented shortening by rotating anticlockwise about vertical axes. I begin by characterising the Altay faults, and add to what is already known about their surface expression with new observations of active faulting and three previously undescribed ancient earthquake ruptures. I use <sup>10</sup>Be cosmogenic dating and uranium-series dating on pedogenic carbonate to estimate the average Quaternary rate of slip for two of the major fault zones in the Altay. The slip rate on the Ölgiy fault is constrained to 0.3-2.1 mm/yr<sup>-1</sup>. Results from the Hovd fault are ambiguous, demonstrating the complications encountered with application of Quaternary dating techniques. I measure palaeomagnetic directions from Cretaceous to Pliocene-aged sediments in the eastern Altay to constrain the degree of anticlockwise rotation. Results from thermal demagnetisation of specimens indicate that the eastern Altay has not undergone significant rotation, in contrast with previous studies from the Siberian Altay that reveal almost 40 degrees of anticlockwise rotation. This suggests that the eastern-most Altay fault is too young to have experienced significant rotation, or is kinematically different from the Siberian Altay. I apply apatite fission track (AFT) dating and track length modeling to the central Altay. Results from AFT dating show rapid cooling in the late Cretaceous due to the distal assembly of Central Asia, suggesting that there was pre-existing topography at the start of the Late Cenozoic phase of deformation, the timing of which is constrained to have initiated at least 20 Myr ago. My work demonstrates that combining results from techniques that cover a variety of time scales quantifies the evolution of active faulting and deformation in the region.
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Shelef, Eitan Oskin Michael. "Deformation processes adjacent to active faults examples from eastern California /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,2066.
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Thesis (M.S.)--University of North Carolina at Chapel Hill, 2008.<br>Title from electronic title page (viewed Feb. 17, 2009). "... in partial fulfillment of the requirements for the degree Master of Science in the Department of Geological Sciences." Discipline: Geology; Department/School: Geological Sciences. Includes supplemental map.
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Toda, Shigeru. "Typical Deformation Modes of Active Faults in the Kinki Region, Central Japan." 京都大学 (Kyoto University), 1999. http://hdl.handle.net/2433/181438.
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Thompson, Stephen C. "Active tectonics in the central Tien Shan, Kyrgyz Republic /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/6744.
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Tarama, Mitsusuke. "Dynamics of active deformable particle - Two types of active spinning motions and dynamics in external flow field -." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199091.
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JAVED, FARHAN. "Earthquake Transients and Mechanics of Active Deformation: Case Studies from Pakistan and Italy." Doctoral thesis, Università degli Studi di Trieste, 2017. http://hdl.handle.net/11368/2908200.
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The understanding of the dynamics of the lithosphere and dominant physical processes during the earthquake cycle is important to estimate the seismic hazard of a given region. In the present study, we rely on seismology to image the geometry of both lithosphere and seismogenic faults and on geodesy to quantify the surface deformation and then we model the time-dependent dynamics of the coupled lithosphere-fault system.
In the first part of the work, we study two earthquake transients, in which, one lasts for a few years following the 2005 Mw 7.6 Kashmir’s earthquake and the second exhibits deformation for a couple of weeks before the 2009 Mw 6.3 L’ Aquila earthquake in the central Apennines, and model the long term inter-seismic deformation across the Idrija fault in the Dinarides (Western Slovenia). In this part of work, we report on the dominant physical process during different phases of the earthquake cycle, namely the postseismic and preseismic phases.
In the second part of the work, we investigate the temporal change of stress state over the Dinarides and Eastern Alps through the coseismic stress changes induced by earthquakes in this region, together with the related post-seismic and interseismic changes due to relaxation processes and interseismic loading. In the last part of the work, we study the dynamics of a dense lithosphere over a weak asthenosphere beneath the Adria plate and model the present day crustal deformation in the peri-Adriatic region including the Apennines, the Alps, and the Dinarides. The implications of these investigations stand in the understanding of how deformation at the plate boundary scale is transferred to active faults accounting also for transients in the system.<br>The understanding of the dynamics of the lithosphere and dominant physical processes during the earthquake cycle is important to estimate the seismic hazard of a given region. In the present study, we rely on seismology to image the geometry of both lithosphere and seismogenic faults and on geodesy to quantify the surface deformation and then we model the time-dependent dynamics of the coupled lithosphere-fault system.
In the first part of the work, we study two earthquake transients, in which, one lasts for a few years following the 2005 Mw 7.6 Kashmir’s earthquake and the second exhibits deformation for a couple of weeks before the 2009 Mw 6.3 L’ Aquila earthquake in the central Apennines, and model the long term inter-seismic deformation across the Idrija fault in the Dinarides (Western Slovenia). In this part of work, we report on the dominant physical process during different phases of the earthquake cycle, namely the postseismic and preseismic phases.
In the second part of the work, we investigate the temporal change of stress state over the Dinarides and Eastern Alps through the coseismic stress changes induced by earthquakes in this region, together with the related post-seismic and interseismic changes due to relaxation processes and interseismic loading. In the last part of the work, we study the dynamics of a dense lithosphere over a weak asthenosphere beneath the Adria plate and model the present day crustal deformation in the peri-Adriatic region including the Apennines, the Alps and the Dinarides. The implications of these investigations stand in the understanding of how deformation at the plate boundary scale is transferred to active faults accounting also for transients in the system.
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Thompson, Thomas Ben. "Active deformation of the Shargyn Basin, a transpressional strike-slip intersection in western Mongolia." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/114129.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2013.<br>"June 2013." Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 37-41).<br>Intraplate faulting in central Asia is a major component of the Indo-Eurasian collision. The kinematics and mechanisms of intraplate deformation are important in understanding broad active tectonic patterns, reconstructing past tectonics, analyzing seismic hazard and identifying potential resources. We examine the fault kinematics surrounding the 150 km wide Shargyn Basin at the intersection of the left-lateral transpressional Gobi-Altai fault system and the right-lateral transpressional Altai fault system. The studies were performed using satellite data and targeted field transects. The results suggest the Shargyn basin is formed by a compressional stepover, an uplifted wedge from the intersecting strike-slip systems and many strike-slip terminating thrust splays. Furthermore, local foliation is almost always fault parallel, pointing to the importance of pre-existing structural weaknesses in the development of active faults. This research demonstrates some of the potential kinematics for intraplate transpressional orogenies and emphasizes the importance of pre-existing crustal structure in the development of active faults.<br>by Thomas Ben Thompson.<br>S.B.
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Alvarado, Alexandra. "Néotectonique et cinématique de la déformation continentale en Equateur." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENU026/document.
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Situé dans le contexte d’une subduction rapide, (vitesse de convergence de 6-8 cm/an), l’Equateur est particulièrement exposé au risque sismique. La composante de la sismicité qui est directement attribuée au processus de subduction est depuis quelques années l’objet de nombreuses études, mais la sismicité “indirecte” due aux processus de déformation dans la plaque supérieure reste peu étudiée. Pourtant, les populations sont directement exposées à cette séismicité intracontinentale, qui reste dangereuse en raison de sa faible profondeur et distance aux zones densément peuplées.Le premier objectif de cette thèse est l’étude de la cinématique régionale, dominée par la présence d’un grand système de failles continentales décrochantes qui s’étend depuis la marge active (Golfe de Guayaquil) jusqu’à la frontière Colombienne. De nombreuses failles associées au processus d’extrusion du Bloc Nord Andin montrent une trace géomorphologique très nette mais ne sont pourtant pas cartées car les accès terrain ne permettent pas de conclure sur leur activité. L’analyse des photos aériennes, d’images satellite et de MNT à différentes échelles nous a permis d’établir tout d’abord un catalogue tectonique des structures majeures, homogène et systématique, puis de déterminer la cinématique de la plupart des structures actives en Equateur à l’échelle Quaternaire. De plus, nous avons intégré l’information sismologique (sismicité et mécanismes au foyer) et géodésique disponible à partir des réseaux nationaux de l’Equateur. Ceci nous a permis d’apporter des contraintes cinématiques sur le fonctionnement de ces structures et comparer les processus de déformation instantanés et cumulés à l’échelle du Quaternaire. Le système tectonique majeur d’Equateur Chingual-Cosanga-Pallatanga-Puná (CCPP) montre une vitesse moyenne de 7 à 8 mm/an par rapport à Sud Amérique. Les structures qui le définissent sont principalement transpressives dextres, avec une distribution nette de la composante décrochant sur les failles de direction NE-SW, et de la composante inverse sur les structures plutôt NS. Ce système tectonique majeur permet l’extrusion vers le nord du Bloc Nord-Andin. Notre interprétation implique l’existence et la définition d’un nouveau microbloc, isolé sur le flanc Ouest de la structure CCPP, qui est limité à l’ouest par les systèmes chevauchants de Quito et Latacunga, et à l’est par les failles du système Chingual Cosanga, depuis environ 3 Ma.Dans un deuxième temps, l’analyse des marqueurs morphologiques de la déformation et de l’évolution des réseaux de drainage associée à un travail de détail sur le terrain et de datations nous ont permis d’étudier cette deuxième région particulière des Andes d’Equateur. Le système de chevauchements de Quito est formé par des failles inverses aveugles qui produisent en surface une série de plis en échelon à vergence Ouest dans les dépôts volcaniques Quaternaire. Cette cinématique est confirmée par l’analyse de la sismicité superficielle et locale, et les mécanismes au foyer issus du réseau national RENSIG. Les données GPS montrent un taux de raccourcissement EW de 4 mm/an, accommodé sur cette structure compressive particulièrement active à l’échelle régionale. En profondeur le système de faille de Quito se connecte probablement vers l’ouest à l’ancienne suture, qui marque la limite des terrains océaniques accrétés au continent. L’analyse du réseau de drainage souligne de plus la propagation du système de failles de Quito vers le nord et vers l’Est, depuis le Quaternaire récent.Pour finir, à partir de ces nouveaux modèles locaux et régionaux de déformation Quaternaire pour l’Equateur, nous avons caractérisé et défini 19 nouvelles sources sismogéniques pour la croûte continentale. Cet apport permettra d’intégrer la tectonique active dans les futurs calculs d’aléa sismique pour aider à la définition du risque sur le territoire Equatorien<br>Located in the Northern Andes along the active subduction zone of the Nazca plate beneath the South American continent, Ecuador is highly exposed to seismic risk. Moreover, the upper plate is actively deforming and faults responsible for crustal earthquakes are poorly known, showing the need to take them into account in modern assessments of seismic hazard.Our first objective is then the study of regional active faults and their kinematics, in Ecuador. Systematic analysis of air photos and satellite imagery, as well as geomorphic evidences gathered at different scales along these structures permitted us to obtain a regional tectonic map. Each observation was taken in account if also confirmed on digital terrain models (DTM) and field data. Finally this first step permitted to establish a first up-to-date and homogeneous catalog of major tectonic structures, active at the Quaternary time scale, consistent over the entire territory. We also determined the sense of motion of these active faults in Ecuador. Additionally, we integrate the seismic (instrumental and historical seismicity together with focal mechanisms for the higher magnitude events) and geodetic data available from national, global networks and field work to derive consistent kinematics models. Finally, the kinematics of each segment is compared to the instantaneous and cumulated Quaternary deformation.We are thus able to document a major tectonic system in Ecuador: the Chingual-Cosanga-Pallatanga-Puná fault system, showing a relative velocity of 7-8 mm/yr. with respect to South America. The deformation is characterized mainly by a combination of dextral NE-SW transpressive faults and reverse NS faults. This system accommodates the northward tectonic extrusion of the North Andean Block. Our interpretation implies the existence and definition of a new micro block, isolated on the western flank of the CCPP structure, bounded on the west by the thrust fault system of Quito and Latacunga and to the east by the Chingual-Cosanga faults, probably active over the past 3 million years.In a second step, the analysis of the evolution of the drainage system and its interaction with the active tectonic deformation, together with focused sampling and dating was applied to the study of a particular region of the Andes of Ecuador: the Latacunga and Quito micro-block together with the Quito faults system. The Quito reverse faults system consists of blind thrust faults that outcrop at the surface as a series of en-echelon folds, dipping west and affecting Quaternary volcanic deposits. This kinematics is further confirmed by the analysis of surface and local seismicity and focal mechanisms provided mainly by the national network RENSIG. Available GPS data show a EW convergence at a rate of 4 mm/yr, which is accommodated on the Quito fault system, and particularly active at a regional level. At depth the Quito fault system is probably connected to the west to the old suture, which marks the limit of oceanic terranes accreted to the continent. The analysis of the drainage system has allowed us to highlight the propagation of Quito fault system eastward and northward during the Quaternary.To conclude from the new local and regional models of Quaternary deformation in Ecuador, we have characterized and defined new seismic sources for the continental crust. Each source corresponds to a characteristic magnitude value and deformation model. This contribution integrates active tectonics as should be done in future seismic hazard calculations to help better quantity seismic hazard on Ecuadorian territory
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McFarland, Phillip K., Richard A. Bennett, Patricia Alvarado, and Peter G. DeCelles. "Rapid Geodetic Shortening Across the Eastern Cordillera of NW Argentina Observed by the Puna-Andes GPS Array." AMER GEOPHYSICAL UNION, 2017. http://hdl.handle.net/10150/626449.
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We present crustal velocities for 29 continuously recording GPS stations from the southern central Andes across the Puna, Eastern Cordillera, and Santa Barbara system for the period between the 27 February 2010 Maule and 1 April 2014 Iquique earthquakes in a South American frame. The velocity field exhibits a systematic decrease in magnitude from similar to 35mm/yr near the trench to <1mm/yr within the craton. We forward model loading on the Nazca-South America (NZ-SA) subduction interface using back slip on elastic dislocations to approximate a fully locked interface from 10 to 50km depth. We generate an ensemble of models by iterating over the percentage of NZ-SA convergence accommodated at the subduction interface. Velocity residuals calculated for each model demonstrate that locking on the NZ-SA interface is insufficient to reproduce the observed velocities. We model deformation associated with a back-arc decollement using an edge dislocation, estimating model parameters from the velocity residuals for each forward model of the subduction interface ensemble using a Bayesian approach. We realize our best fit to the thrust-perpendicular velocity field with 705% of NZ-SA convergence accommodated at the subduction interface and a slip rate of 9.10.9mm/yr on the fold-thrust belt decollement. We also estimate a locking depth of 149km, which places the downdip extent of the locked zone 13520km from the thrust front. The thrust-parallel component of velocity is fit by a constant shear strain rate of -19x10(-9)yr-(1), equivalent to clockwise rigid block rotation of the back arc at a rate of 1.1 degrees/Myr.
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Walters, Richard John. "Geodetic observation and modelling of continental deformation in Iran and Turkey." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:39c0e88a-4f45-483a-b8e1-6a7dc3e9d41b.
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In this thesis I use Interferometric Synthetic Aperture Radar (InSAR) and GPS geodetic observations, along with numerical models, to examine the distribution of strain, assess seismic hazard, and study the dynamics of deformation across Turkey and Iran. I measure interseismic strain accumulation across the Ashkabad fault using InSAR, and find that atmospheric corrections using MERIS (Medium Resolution Imaging Spectrometer) data are necessary in order to retrieve the tectonic signal in the presence of large atmospheric delays. I estimate a slip rate of 5-12 mm/yr for the Ashkabad fault which is faster than previous geodetic estimates. I also attempt to validate atmospheric corrections derived from the ERA-Interim numerical weather model and find that they do not work satisfactorily for this region. I produce InSAR-derived velocity maps for five overlapping tracks in Eastern Turkey, covering both the North Anatolian Fault (NAF) and East Anatolian Fault (EAF), and measure slip rates for the NAF and EAF of 20+/-3 mm/yr and 10+/-2 mm/yr respectively. I calculate a velocity field for Eastern Turkey from these InSAR data and a compilation of GPS data, and find that strain is mainly localised across the NAF and EAF and that there is negligible differential vertical motion across the Anatolian Plateau. I construct a thin viscous sheet model for Iran and find that the GPS velocity field is well described by deformation of a ductile lithosphere. Contrary to previous suggestions, a rigid central Iran is not required to match the kinematics of Iranian deformation, but buoyancy forces acting in the lithosphere are found to play an important role. I develop a new method to assess slip rates and therefore seismic hazard on major faults in Iran from this continuum model. In this thesis I have measured slip rates across three major strike-slip faults using InSAR; the first time this has been achieved for the Ashkabad fault and the EAF. I have demonstrated the importance of atmospheric correction for these results, and have shown that Iran deforms as a continuous medium.
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Sorby, Andrew Peter. "The temporal and spatial distribution of active deformation in the Basin and Range Province, Western U.S.A." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414273.
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Fougere, Samuel Richard. "Paleoseismicity and active earth deformation, Lake Rotoiti to West Wairau Valley section of the Alpine Fault." Thesis, University of Canterbury. Engineering Geology, 2002. http://hdl.handle.net/10092/6962.
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The Wairau Fault, the northern extension of the Alpine Fault, has not ruptured historically. Bounding the Marlborough Fault System to the north the Wairau Fault is over 100 km long and capable of generating a large earthquake rupture. From Cloudy Bay SW to Lake Rotoiti the fault is defined by a linear valley-bound trace and narrow zone of deformation. The main objective of this paleoseismic investigation of a section of this fault was to establish the pre-historic rupture history.
Trenching excavations, geomorphic mapping, differential GPS surveying and weathering rind dating techniques were used to investigate the rupture history of the Wairau Fault.
From trenching data at Tophouse, one earthquake rupture on the Wairau Fault is recorded since AD 200. No upper limit bounds this rupture date. Integration with a similar paleoseismological study of Zachariasen et al, (2001) refines the last rupture event on the Wairau Fault to between AD 200 - 1000. A branch caught in the shear zones indicates a dated event approximately 12 500 years ago but other events intervene on stratigraphic evidence. Liquefaction deposits are recognised in the trenches, in conjunction with small thrust flaps on the footwall side, suggesting seismic rupture as the dominant translation mechanism, with no significant aseismic creep based on offset linear terraces.
Dextral slip rates on the fault of 4.2 ± 1.4 mm/yr compares well with pre-existing data. A single event offset of 4.4 ± 0.5 m is consistent with others further NE along the Wairau Valley.
A temporal disparity exists between the last rupture brackets at the Tophouse and Matakitaki River trenches (Yetton, 2002), indicating that, at least for the last rupture event an earthquake segment boundary was operational between the two trench sites. Defining an earthquake rupture segment boundary by a specific structure or location is difficult as any number of faults could dissipate radiated seismic energy and several possibilities are reviewed. If a rupture segment does exist between Matakitaki River and Tophouse, it is most likely about Lake Rotoiti. An estimated earthquake magnitude for the onland section of the Wairau Fault for this rupture segment is M = 7.4 ± 0.25.
In addition to aspects of seismicity of the fault strike, both the large scale topographic setting and detailed morphology of the fault zone are discussed. In particular the complexity of interaction between fluvial processes and secondary deformation associated with the fault zone has lead to some insights into both the evolution of secondary structures and to the response of rivers behaviour to seismic cycles.
On the basis of elapsed time since the last fault rupture, and slip rates on the fault, an earthquake rupture on the Wairau Fault in the near future is a distinct possibility.
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GASPERI, JEROME. "Etude de la deformation lithospherique active par interferometrie radar. Application a la region de hengill, islande." Toulouse 3, 1999. http://www.theses.fr/1999TOU30232.
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L'interferometrie radar est un outil de mesure satellitaire particulierement adapte a la geophysique. Il permet de dresser une carte temporelle de la deformation lithospherique avec une precision centimetrique. Nous avons applique cette technique a la region volcanique de hengill, au sud-ouest de l'islande afin d'y mesurer la deformation entre 1993 et 1998. Situee a moins de 100 kilometres de la capitale reykjavik, la region de hengill est une zone sismiquement active qui subit depuis 1994 un regain d'activite sismique. La stabilite de l'etat de surface des champs de laves qui recouvrent la region permet d'obtenir une bonne coherence interferometrique sur des intervalles de quatre ans. Le signal principal observe sur les interferogrammes est un reseau de franges concentriques centre au sud du volcan hromundartindur. Ce signal correspond a un gonflement de la zone du a l'augmentation de pression dans une chambre magmatique situee a 7 km de profondeur sous la surface. Le taux de surection, de l'ordre de 2 cm/an, est constant entre 1993 et 1998. Ce gonflement augmente suffisamment la contrainte de coulomb sur des failles verticales pour declencher des seismes. Lors de ces seismes, la contrainte est liberee. Le mecanisme d'accumulation-relachement de la contrainte, dont la chambre magmatique est le moteur, a lieu de maniere cyclique avec un intervalle de recurrence de l'ordre de 10 ans pour un seisme de magnitude 5.
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Guilbaud, Christelle. "Kinematics of active deformation of the Western Kunlun Range (Xinjiang, China) : implications for potential seismic hazards." Thesis, Université de Paris (2019-....), 2019. http://www.theses.fr/2019UNIP7112.
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La chaîne du Kunlun Occidental est une chaîne de montagnes intra-continentale en déformation lente, située à la bordure Nord-Ouest du plateau du Tibet. Malgré des évidences de raccourcissement au travers de la chaîne durant le Cénozoique, les taux de raccourcissement actuels sont trop faibles pour être quantifiés par les techniques géodésiques classiques. Par ailleurs, cette région n’a enregistré que peu de sismicité, mais le récent séisme de Pishan en juillet 2015 (Mw 6.4) atteste encore de son activité de nos jours. Dans cette thèse, nous cherchons à identifier les structures actives qui accommodent actuellement le raccourcissement, ainsi qu’à quantifier le taux de raccourcissement au travers de la chaîne, et à explorer la possibilité d’avoir de grands séismes dans cette région.Nous nous concentrons tout d’abord sur la zone épicentrale du séisme de Pishan. En combinant une analyse d’images satellites et de MNT, nous identifions neuf niveaux de terrasses fluviales et de surfaces alluviales incisées au niveau du pli de Yecheng-Pishan. Grâce à certains niveaux datés et à l’enregistrement de leur incision, nous quantifions le taux de raccourcissement sur cette structure à 0.5-2.5 mm/an sur les derniers 400 ka, avec une valeur long-terme plus probable entre 2-2.5 mm/an. A l’aide d’une étude structurale basée sur des cartes géologiques, données de terrain et profils de sismique réflexion du front de chaîne, nous identifions l'écaille chevauchante frontale formant le front de déformation de la chaîne du Kunlun Occidental. Cette écaille est enracinée dans un décollement superficiel, émergeant en surface au sein du bassin du Tarim, 150 à 180 km au nord du front morphologique de la chaîne, au niveau de la ride du Mazar Tagh. De telles dimensions impliquent la possibilité de grands séismes (M>8) si ce décollement était actuellement bloqué et venait à rompre en une fois. Afin d'explorer la potentielle segmentation structurale et d’éventuelles variations du taux de raccourcissement le long du front de chaîne, une étude morpho-structurale du pli de Hotan, situé ~100 km à l'est de Pishan, est menée. Trois coupes géologiques sont réalisées au travers de cette structure, puis combinées avec l’analyse morphologique de terrasses fluviales. Ainsi, malgré des variations sur le nombre de structures aveugles accommodant la déformation active, le taux de raccourcissement semble similaire tout le long du front de chaîne. Ce scénario semble toutefois avoir été plus complexe dans le passé géologique. Enfin, pour avoir une meilleure compréhension de la façon dont la déformation est accommodée au travers de ce système de failles, et afin de vérifier la viabilité de la cinématique connectant le front de chaîne au Mazar Tagh, nous réalisons une nouvelle étude morpho-structurale de la zone où la rampe émerge en surface au cœur du bassin du Tarim. Une coupe géologique est construite à partir d’un profil sismique, permettant d’obtenir la géométrie précise de la rampe. Malgré l’aridité de la région, des terrasses ont été identifiées et échantillonnées pour datation OSL et 10Be. Ces terrasses sont ensuite cartographiées afin de quantifier la déformation enregistrée par ces marqueurs. Cette analyse nous permet ainsi de montrer que la déformation est bien transmise jusqu’à la rampe émergeant en surface au Mazar Tagh. Nous explorons ensuite le potentiel aléa sismique de la région en étudiant des marqueurs morphologiques qui pourraient avoir enregistré des séismes passés. Nos résultats apportent de ce fait une meilleure connaissance des structures actives et de la cinématique de la déformation dans cette chaîne de montagnes, et permettent de discuter du potentiel aléa sismique de la région<br>The Western Kunlun mountain range is a slowly converging intra-continental orogen located at the northwestern boundary of the Tibetan Plateau. Despite evidence of shortening through the range during the Cenozoic, present-day shortening rates are too low to be properly quantified from geodetic techniques. This region has also recorded limited seismicity, but the recent July 2015 (Mw 6.4) Pishan earthquake shows that this mountain range remains seismic. In this thesis, we aim at identifying the structures that actively accommodate this deformation across the range, at quantifying their slip rate and at exploring the potential for major earthquakes in this region.To do so, we first focus on the epicentral zone of the Pishan earthquake. Combining analysis of satellite images and DEMs, we obtain a detailed morphological analysis of the Yecheng-Pishan fold and find nine levels of incised fluvial terraces and alluvial fans. From their incision pattern and using age constraints available on some of these terraces, we are able to quantify the slip rate on the underlying blind frontal ramp to 0.5 to 2.5 mm/yr over the last ~400 kyr, with a most probable long-term value of ~2.0-2.5 mm/yr. Thanks to a structural study of the mountain front based on topographical and geological maps, field observations and available seismic profiles, we also identify a major active thrust sheet forming the deformation front of the Western Kunlun Range. This thrust sheet roots into a shallow decollement that emerges at the surface 150-180 km further north within the Tarim Basin, at the Mazar Tagh ridge. Such important dimensions imply the possibility of major M ≥ 8 earthquakes in the case that the whole decollement is presently seismically locked and fully ruptures in one single seismic event. With the idea of exploring potential along-strike structural segmentation or variations in deformation rate or in kinematics along the mountain front, a morpho-structural analysis is also conducted at the Hotan anticline, located ~100 km east of the Pishan epicentral area, along the morphological front of the Western Kunlun. Here, we build three geological cross- sections and investigate the record of preserved fluvial terraces. Despite a change in the number of active blind structures accommodating deformation, the slip rate remains similar along the mountain front. This pattern may however have been more complex in the geological past. Finally, to have a better understanding on how this deformation is accommodated through this fault system and to further test the possibility that the Mazar Tagh is really structurally and kinematically related to the folds of the mountain front, we conduct a new morphological and structural analysis of the most frontal ramp emerging at the Mazar Tagh ridge. A structural cross-section is built thanks to the combination of a seismic profile crossing the ridge and using field measurements, allowing us to get the precise geometry of the emerging ramp. Despite the current aridity of the region, a set of terraces is identified and sampled in the field for OSL and 10Be dating. Using Pléiades images and derived DEMs, we map theses terraces to quantify the amount of deformation recorded by these markers. This analysis shows that the kinematics proposed is viable and deformation is most reasonably transmitted from the topographic front of the Western Kunlun Range all the way to the Mazar Tagh emerging ramp. We also investigate potential geomorphic markers that may keep a record of past mega-earthquakes at this site of the deformation front. Our results help us get a better knowledge on the structure and kinematics of this range and its deformation front, and to discuss potential seismic hazards in this slowly deforming region
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AREGGI, GIULIA. "Surface deformation analysis in Northeast Italy by using PS-InSAR and GNSS data." Doctoral thesis, Università degli Studi di Trieste, 2022. http://hdl.handle.net/11368/3030759.
Full textAbstract:
In the present study, we exploited the potential of satellite-based geodetic data for detecting and measuring surface displacement in Northeast Italy. In this contest, we focused mainly on 1) the estimation of the interseismic deformation during the satellites’ observation period, 2) the detection and analysis of the main deformation patterns, and 3) the correlation of the signals to the active tectonic structures.
Despite the low convergence rates (~ 1.5-3 mm/yr), Northeast Italy is an active tectonic area, as testified by the instrumental and historical seismicity. The Adria-Eurasia convergence is mainly accommodated by the thrusts and strike-slip faults of the Southeastern Alps and the External Dinarides, located in the northern and northeastern sectors of the study area. The Venetian-Friulian plain and the Adriatic coasts, affected by active subsidence, dominate the southern region.
We used the Stanford Method for Persistent Scatterers (StaMPS) applied to Sentinel-1 SAR images acquired along the ascending and descending orbit tracks between 2015 and 2019. Based on a stack of single-master differential interferograms, we detected coherent and temporally stable pixels based on amplitude and phase noise analysis. After applying spatial-temporal filters and additional post-processing operations to refine the measurements, we used Adria-fixed GNSS velocities derived by permanent stations in the study area to calibrate the InSAR velocities.
The outcome consists of Line-OF-Sight (LOS) mean ground velocity maps derived by displacement time series along the radar directions for each satellite track. The combination of the LOS datasets yields vertical and east-west velocity maps, which are mostly in agreement with GNSS data and previous geodetic studies.
Based on our measurements, we observe a significant positive velocity gradient of 1 mm/yr across the westernmost sector of the Alpine system, suggesting an aseismic motion of the root of the Bassano-Valdobbiadene thrust.
The positive vertical gradients (~1 and up to 2 mm/yr) across the Alpine-Dinaric systems in the central and eastern sectors and the eastward motion that increases northeastward (1-2 mm/yr) may be related to the active Alpine-Dinaric thrusts and strike-slip faults. We also suggest that the detected westward motion of the Friulian plain (around Udine) might be attributed to the presence of tectonic structures characterized by transcurrent-transpressive kinematics. Finally, we detect other signals, such as the significant subsidence (2-4 mm/yr) along the coasts and on the southern Venetian-Friulian plain, confirming the correlation between subsidence and the geological setting of the study area.
In conclusion, our study confirms the potential of MT-InSAR and GNSS data for the estimation of the surface deformations in response to active tectonics, even in areas characterized by low deformation rates, such as Northeast Italy.<br>In the present study, we exploited the potential of satellite-based geodetic data for detecting and measuring surface displacement in Northeast Italy. In this contest, we focused mainly on 1) the estimation of the interseismic deformation during the satellites’ observation period, 2) the detection and analysis of the main deformation patterns, and 3) the correlation of the signals to the active tectonic structures.
Despite the low convergence rates (~ 1.5-3 mm/yr), Northeast Italy is an active tectonic area, as testified by the instrumental and historical seismicity. The Adria-Eurasia convergence is mainly accommodated by the thrusts and strike-slip faults of the Southeastern Alps and the External Dinarides, located in the northern and northeastern sectors of the study area. The Venetian-Friulian plain and the Adriatic coasts, affected by active subsidence, dominate the southern region.
We used the Stanford Method for Persistent Scatterers (StaMPS) applied to Sentinel-1 SAR images acquired along the ascending and descending orbit tracks between 2015 and 2019. Based on a stack of single-master differential interferograms, we detected coherent and temporally stable pixels based on amplitude and phase noise analysis. After applying spatial-temporal filters and additional post-processing operations to refine the measurements, we used Adria-fixed GNSS velocities derived by permanent stations in the study area to calibrate the InSAR velocities.
The outcome consists of Line-OF-Sight (LOS) mean ground velocity maps derived by displacement time series along the radar directions for each satellite track. The combination of the LOS datasets yields vertical and east-west velocity maps, which are mostly in agreement with GNSS data and previous geodetic studies.
Based on our measurements, we observe a significant positive velocity gradient of 1 mm/yr across the westernmost sector of the Alpine system, suggesting an aseismic motion of the root of the Bassano-Valdobbiadene thrust.
The positive vertical gradients (~1 and up to 2 mm/yr) across the Alpine-Dinaric systems in the central and eastern sectors and the eastward motion that increases northeastward (1-2 mm/yr) may be related to the active Alpine-Dinaric thrusts and strike-slip faults. We also suggest that the detected westward motion of the Friulian plain (around Udine) might be attributed to the presence of tectonic structures characterized by transcurrent-transpressive kinematics. Finally, we detect other signals, such as the significant subsidence (2-4 mm/yr) along the coasts and on the southern Venetian-Friulian plain, confirming the correlation between subsidence and the geological setting of the study area.
In conclusion, our study confirms the potential of MT-InSAR and GNSS data for the estimation of the surface deformations in response to active tectonics, even in areas characterized by low deformation rates, such as Northeast Italy.
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Streig, Ashley. "High Resolution Timing and Style of Coseismic Deformation: Paleoseismic Studies on the Northern and Southern San Andreas Fault." Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/18379.
Full textAbstract:
Critical inputs to evaluate fault behavior models include the frequency of large earthquakes on plate boundary faults, amount of displacement, style of deformation in these events, and how these earthquakes are associated with adjacent sites and broader segments. Paleoseismic data provide these inputs and allow the characterization of hazard posed by individual faults. This dissertation presents results from paleoseismic studies at Hazel Dell and Frazier Mountain that provide new earthquake chronologies and slip estimates for the San Andreas Fault (SAF). These data provide new insights into the recurrence and style of coseismic deformation for surface rupturing earthquakes on the SAF.
The Hazel Dell site provides the first definitive paleoseismic evidence of two pre-1906, 19th century earthquakes on the Santa Cruz Mountains section of the SAF. I correlate these paleoseismic findings with the historic record of ground shaking associated with earthquakes in that period and combine the style of deformation in the last 3 events at the site with results from nearby paleoseismic sites to estimate earthquake rupture lengths and magnitudes for these early historic events. These findings increase the frequency of historic surface rupturing earthquakes on the northern SAF three-fold. At the Frazier Mountain site, on the southern SAF, I mapped deformation across a releasing step on the fault for the last five surface rupturing earthquakes to estimate deformation per-event. I compare the geometry and amount of vertical relief generated across the step-over by retrodeforming 3D surfaces interpolated from paleoseismic data step-wise for stratigraphic units deformed by each of those earthquakes. I find that structural relief is similar in four of the last five events, so slip on the fault must be within the same range for these earthquakes to generate approximately equivalent structural relief across the step-over. These results suggest displacement on the fault is comparable at the Frazier Mountain site for the last 4 events, including deformation resulting from 4-5 m lateral displacements in the historic M 7.9 1857 earthquake.
This dissertation includes previously published and unpublished coauthored material. Supplemental file Plate A includes additional trench logs for the Hazel Dell site, presented in Chapters II and III.
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Grassi, Sabrina. "Characterization of active tectonic structures of the Etna volcano, through geophysical surveys, analysis of site response and deformation." Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3902.
Full textAbstract:
In this thesis are shown the results of a multidisciplinary research, including geophysical, structural and geodetic surveys, carried out along the Tremestieri-Trecastagni-San Gregorio-Acitrezza fault system with the aim to provide additional insightful about its geometry and kinematics; also, additional geophysical surveys were performed at various sites of the municipalities most affected by the fault segments presence in order to obtain information on site response. This fault system, considered as "laboratory structure", was selected for the different kinematic characteristics and different modes of strain-energy release, that characterized its fault segments.
In the northernmost portion, this system has a kinematic behavior of normal fault and releases energy during coseismic deformation, while in the southernmost portion presents a kinematic behavior of a right-lateral strike-slip fault with releases energy during aseismic creep. Furthermore, this fault system, which can be considered the southern boundary of the sliding of Etnean eastern slope, was less studied than the northern sliding boundary and very little is known about the depth geometry of its fault segments.
The surveys were performed after an analysis of the data relating to shallow geology and to morphological, structural, stratigraphic, geophysical and seismological aspects; these detailed surveys have confirmed and highlighted a variety of geological and geomorphological conditions that can determine the existence of different stress following the occurrence of an earthquake.
After have performed a detailed structural survey, the project has planned the acquisition and analysis of many ambient noise samplings, and of other geophysical surveys, undertaken within the municipalities affected by the presence of the fault segments, increasing the surveys near the fault. All this in order to reconstruct the resonance frequency distribution and detect the possible presence of areas affected by amplification effects.
Moreover, in some areas, the surface deformation process was characterized through the design, implementation and installation, across the fault segments, of a geodetic monitoring network, in order to obtain information on the fault kinematics and on the local stress field.
The integration of the results obtained from structural, geological and geophysical surveys, with a complete literature review has provided important information on the development in depth of the fault segments; it was thus possible to reconstruct a 3D model of geometry that characterized the southern boundary of Etnean eastern slope sliding.
Various deformation data such as GPS displacements, InSAR images, level data and measures with extensometers suggest that the slip along the fault system is not uniform, but can be better described by a distribution of dislocation sources along the fault surfaces. In order to model the slip distribution along the fault surfaces, an inverse modeling of DInSAR deformation data was carried out.
This project was aimed to the recognizing site effects, that characterize the studied areas, in order to highlight the seismo-stratigraphic and tectonic behavior of subsoil, as well as, to the characterization of the deformation field related to the fault segments, through the implementation of a new geodetic monitoring network (GEO-UNICT geodetic network).
The results allowed to obtain important information on all parameters that can increment the local seismic hazard; all these different but converging approaches, have permitted a complete study of the investigated area. This study providing essential information for a proper land use planning, having as main objective the mitigation of risks that can affect the population.
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Brothelande, Elodie. "Etude d'une résurgence active dans la caldera de Siwi (Tanna, Vanuatu) : le système Yenkahe-Yasur." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22571/document.
Full textAbstract:
La résurgence, définie comme le soulèvement du plancher des calderas postérieurement à leur effondrement, est largement répandue mais encore très mal comprise. L'objectif de cette thèse est l'étude pluridisciplinaire d'un dôme résurgent: le Yenkahe, au sein de la caldera de Siwi au Vanuatu. L'intérêt de ce dôme est multiple. D'une part, la résurgence est active, d'autre part, elle est très rapide donc elle est associée à des structures relativement préservées. Enfin le Yenkahe présente l'originalité d'être associé à un cône volcanique en éruption permanente depuis au moins plusieurs centaines d'années: le Yasur. Une première étude tectonique basée sur des observations de terrain, complétées par l'exploitation d'images satellites et de modèles numériques de terrain à basse résolution existants, a permis de mettre en évidence une histoire en deux temps (au moins) de la croissance du dôme résurgent. Une première phase de croissance verticale engendrant un graben longitudinal aurait été suivie par une seconde phase de déplacement vers l'est de la source de la déformation, occasionnant un soulèvement de la partie est du dôme par rapport à la partie ouest. Ces grands traits structuraux ont pu être raffinés, par la suite, par le calcul d'un modèle numérique de surface à haute résolution issu de la photogrammétrie. Outre le haut niveau de détails permettant une cartographie plus fine des failles, ce modèle a apporté la mise en évidence de nombreuses traces de déstabilisations sur les flancs du Yenkahe. Dans l'avenir, de telles déstabilisations pourraient engendrer des tsunamis atteignant des zones habitées en quelques minutes. Les caractéristiques de la source de déformation à long terme du Yenkahe, et d'autres dômes résurgents présentant une morphologie similaire, ont fait l'objet d'une étude en modélisation analogique (intrusion de silicone dans un mélange de sable-plâtre). Les résultats de cette étude montrent que la taille du graben engendré en surface par l'intrusion d'une source allongée dépend surtout de la profondeur de cette source. On tire de cette étude que l'intrusion associée au Yenkahe, supposée magmatique, serait située aux alentours d'un kilomètre sous la surface.Une seconde étude en modélisation numérique, basée sur un processus de poinçonnement dans un milieu élastoplastique, met en avant une géométrie interne de dôme différente mais confirme l'ordre de grandeur obtenu pour la profondeur de source (1-2 km), rendant le résultat plus robuste. Cette source magmatique est peut-être connectée au Yasur, qui montre une activité de dégazage en conduit ouvert depuis plusieurs centaines d'années. Ceci qui impliquerait un mode de croissance incrémental gouverné par des événements de surpression transitoires (tels que des injections magmatiques). Enfin, un ensemble de méthodes géophysiques appliquées à l'étude de la caldera de Siwi (gravimétrie, mesures magnétiques et électriques, etc.) révèle que l'histoire post-effondrement de cette caldera comporte, outre la résurgence tectonique, des événements effusifs et la construction de plusieurs édifices volcaniques successifs. Ces méthodes mettent également en évidence la présence d'un système hydrothermal très étendu, particulièrement profond (plus de 300 m) et actif à l'est du dôme. L'altération hydrothermale associée pourrait favoriser des déstabilisations de l'édifice résurgent<br>Resurgence, defined as the post-collapse uplift of the caldera floor, is widespread phenomenon worldwide but it is still poorly understood. This work is a multidisciplinary study of a resurgent dome: the Yenkahe dome, located inside the Siwi caldera, in Vanuatu. The relevance of this dome is multiple: firstly, resurgence is currently active, secondly it is fast, so the associated structures are well-preserved, and lastly, the Yenkahe dome presents the originality to be associated with a volcanic cone which has been permanently active for at least several hundred years: the Yasur volcano. A primary tectonic study based on field observations, satellite images and available low-resolution digital elevation models brought the evidence of a two-stage (at least) dome growth history. The first stage is a vertical growth that produced the longitudinal graben on top of the dome. It was followed, in the second stage, by an eastward displacement of the deformation source, generating an uplift of the eastern dome relative to the western dome. The Yenkahe structural map was then refined through the computation of a high-resolution photogrammetric digital surface model (DSM). Besides the great number of details allowing precise fault mapping, this DSM highlights the presence of numerous destabilization scars associated with the evolution of the dome. In the future, similar destabilization events may produce tsunamis reaching inhabited areas in a couple of minutes. The characteristics of the long-term deformation source of the Yenkahe dome, and of other resurgent domes with a similar morphology, were investigated by analogue modeling (intrusion of silicone putty in a sand-plaster mixture). The results of the study show the width of the graben created by an elongated intrusion source mostly depends on the depth of this source. The source of the Yenkahe dome, presumably a magmatic intrusion, would be approximately one-kilometer deep. A second study, based on a punching process in a numerically modeled elastoplastic medium, shows a different internal structure for the dome. However, it confirms the order of magnitude obtained for the source depth (1-2 km), making this result more robust. The presumed magmatic source may be connected to the Yasurvolcano, exhibiting an open conduit activity for several hundred years, which would imply an incremental growth governed by transient over-pressurizing events at depth (such as magma injections). Lastly, a panel of geophysical methods were carried out within the caldera (magnetics, gravimetry, electrical methods, etc.). They revealed that the post-collapse history of Siwi involved, not only resurgence tectonics, but also the emplacement of lava fields and of several volcanic edifices. They also demonstrate the presence of an extended hydrothermal system, particularly deep (more than 300 m) and active on the eastern side of the dome. The associated extended alteration may favor the destabilization of the resurgent edifice
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Burkett, Corey A. "LATE QUATERNARY CRUSTAL DEFORMATION AT THE APEX OF THE MOUNT MCKINLEY RESTRAINING BEND OF THE DENALI FAULT, ALASKA." UKnowledge, 2014. http://uknowledge.uky.edu/ees_etds/25.
Full textAbstract:
The tallest mountain in North America, Mount McKinley is situated inside a sharp bend in the right‐lateral Denali fault. This anomalous topography is clearly associated with the complex geometry of the Denali fault, but how this topography evolves in conjunction with the adjacent strike‐slip fault is unknown. To constrain how this fault bend is deforming, the Quaternary fault‐related deformation on the opposite side of the Denali fault from Mount McKinley were documented through combined geologic mapping, active fault characterization, and analysis of background seismicity. My mapping illustrates an east‐west change in faulting style where normal faults occur east of the fault bend and thrust faults predominate to the west. These faults offset glacial outwash terraces and moraines which, with tentative correlations with the regional glacial history, provide fault slip rates that suggest that the Denali fault bend is migrating southwestward. The complex and elevated regional seismicity corroborates the style of faulting associated with the fault bend and provide additional subsurface control on the location of active faults. Seismologic and neotectonic constraints suggest that the maximum compressive stress axis rotates from vertical east of the bend to horizontal and Denali fault‐normal west of the bend.
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Finnemore, Michael. "The application of seismic reflection surveying to the characterisation of aquifer geometry and related active tectonic deformation, North Canterbury." Thesis, University of Canterbury. Dept. of Geology, 2004. http://hdl.handle.net/10092/10719.
Full textAbstract:
Groundwater resources critical to North Canterbury's agriculture, and industrial sustainability and development are predominately located within the Late Quaternary age (0- 0.78 myr)
sediments that underlie, and form the North Canterbury Plains.
The aim of this research is to determine if shallow seismic reflection P-wave surveying is
capable of delineating sedimentary architecture related to groundwater resources in the glaciofluvial
and fluvial sediments of the North Canterbury Plains and in particular, if (high
porosity/permeability pathways) and aquitard (low permeability) units can be differentiated
and so be applied to understanding groundwater resource in the North Canterbury region.
The research was undertaken in three geographic areas in North Canterbury, which represent
the main environments for Late Quaternary sedimentary deposition. i) The Omihi Valley a
thrust controlled foothill valley setting. ii) The Racecourse Hill-Burnt Hill area which
represents a basin-marginal setting close to the emergence of the glacial outwash fans that
constitutes the Northwest Canterbury composite aggradation surfaces, and iii) Pines Beach, a
more extensively reworked prograding postglacial braidplain with repeated episodes of
marine incursion.
Three methodologies have been developed to identifY aquifer units in the Late Quaternary
sediments of North Canterbury using shallow seismic reflection surveying.
1. Combined structural delineation seismic surveys and borehole logging to define
medium scale (lOrn- 2 km) structures and lithology which affect aquifer and aquitard
location and extents.
2. Tailored two and three dimensional shallow seismic reflection surveys to define
sedimentary architecture within the larger scale sediment packages delineating high
porosity/permeability pathways e.g. paleo-channels in the Omihi Valley and paleo-cut
and fill valleys on the Northwestern Canterbury Plains margin.
3. Changes in seismic reflection attributes which directly reflect sediment changes in
permeability and porosity such as the decrease in interval velocity with reduced matrix
clay/silt content in the Omihi Valley Late Quaternary sediments.
The main research outcome achieved from the 33 km2 Omihi Valley was the integration of
geological/geophysical mapping with lithological borehole logging to develop a groundwater
resource model allowing a predictive approach to its exploration and utilization. Structural
geometry and styles of deformation of the Valley have also been characterised .
The seismic reflection survey results for Burnt Hill and Racecourse Hill, both basin-margin
areas, indicate that seismic surveying can be successfully used to image alluvial and fluvial
architecture at scales from 10m- 1000's m, but with lower lateral ( ~28m@ 100m depth)
and vertical resolution ( 4 m) than that of the Omihi Valley surveys. The interpretation of the
intra-gravel seismic reflections is complex, and likely only to be possible with three
dimensional seismic reflection surveying.
In the third site, only a limited survey of one line was undertaken at Pines Beach (Canterbury
Plains/Pegasus Bay junction). This survey indicates that interfingering of reworked finergrained
fluvial sediments and coastal marine sediments can be successfully characterized with a lateral resolution of< 11 m and vertical resolution of 1.5 m for sediments within the top 50
m.
The research generally demonstrates that shallow seismic reflection P-wave surveying can be
extended to the more laterally extensive North Canterbury Plains as a whole, where it is
capable of delineating subsurface sedimentary facies, including hydrologically important
architecture, down to sub-two metre vertical resolution, in glacio-fluvial, fluvial and shallow
marine derived sediments in the 20 - 500 m depth range. The paleo-sedimentary structures
successfully delineated in the three field areas include paleo-channels, channel fill, large scale
erosional cut-and-fill valleys, floodplain surfaces, and alluvial fans.
It is shown that the aquifer and aquitard contrast in North Canterbury is not characterised by
porosity, but by permeability differences (which are also affected by porosity). Aquifers are
saturated high porosity/permeable sediments with low silt/clay content while aquitards are
saturated units with low permeability which appear (in the Omihi Valley) to be controlled by
silt/clay content, but not necessary low porosity.
P-wave seismic reflection surveying is shown to be insensitive to sediment permeability
variations, but limited data from the Omihi Valley indicates that seismic P-wave velocities
may be sensitive to matrix clay/silt content. If proven elsewhere in the Canterbury Plains
region, this may lead to a method of defining aquifer/aquitard geometry directly, without the
need to use indirect methods such as paleo-fluvial facies architecture delineation.
This thesis concludes that shallow seismic reflection surveying is capable of characterizing
the North Canterbury Plains and foothills valleys sedimentary lithofacies architecture, and
also shallow, tectonically-driven structural deformation, when used as part of a multi-faceted
programme of investigation. These data can be used to delineate the main groundwater
resources. Further research is required to determine if direct aquifer geometry identification is
possible by seismic P-wave interval velocity inversions and to increase seismic reflection
acquisition speed to allow efficient coverage of large areas.
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Armstrong, Mark James. "Geomorphological and geophysical investigation of the effects of active tectonic deformation on the hydrogeology of North Culverden Basin, North Canterbury." Thesis, University of Canterbury. Geological Sciences, 2000. http://hdl.handle.net/10092/4509.
Full textAbstract:
This thesis examines the complex interaction between the tectonic evolution of Culverden Basin and the Late Quaternary sediments, which form the aquifer-bearing deposits, using geological and geomorphological mapping as well as near-surface geophysical investigations.
Along the eastern margin of Culverden Basin, the deformation associated with the actively widening Australian-Pacific plate boundary zone, has resulted in the evolution of Culverden Basin and the progressive inversion of the basin floor. The eastern margin of the basin is structurally controlled by a NE trending, complexly segmented range-front fault system and associated thrust-propagated anticlines forming the basin boundary. Basin inversion is driven by the westward propagation of footwall imbricate thrusts and associated folds. The inversion of the basin floor lead to the creation of sub-basins within the larger basin, which have controlled the distribution and architecture of the Late Quaternary stratigraphy.
The Late Quaternary sedimentary record documents periods of climatically induced aggradation during cold conditions and degradation in the intervening warmer times. The interaction between the sedimentation and ongoing tectonic deformation has resulted in complex lithological relationships between the locally sourced alluvial fans and the glacial outwash deposits of the major rivers entering the basin.
The architecture of the aquifers is therefore controlled by the changing fluvial regime and its interaction with the evolving sub-basins. The progressive evolution of the sub-basins leads to increasing complexities in the facies relationships and to the confinement of the deposits into progressively smaller portions of the sub-basins. Once the basin boundaries become emergent, the basin becomes isolated, and potentially cut-off from its groundwater recharge source.
Leonard Mound is an actively evolving imbricate thrust system along the eastern margin of Culverden Basin that has isolated the Wynyard sub-basin from the central portion of Culverden Basin, during the Late Pleistocene and present. The emergence of Leonard Mound is preventing the recharge to the Wynyard sub-basin from the high yielding aquifers of the central portion of the basin. In the central portion of Culverden Basin, high natural recharge combined with an irrigation scheme has allowed for transformation of the basin into a major dairy farming centre. In contrast, the Wynyard sub-basin is still subjected to frequent summer droughts, making it desirable to find a better source of groundwater for the eastern margin of the basin.
The hydrogeological model provided by the Culverden Basin almost certainly has wider implications to the groundwater resources of other basins in similar active tectonic settings.
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Cetin, Esra. "Analysis and modeling of crustal deformation using InSAR time series along selected active faults within the Africa-Eurasia convergence zone." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAH010/document.
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Les travaux de cette thèse de Doctorat ont été menés dans le cadre de l'accord en co-tutelle entre l'Université de Strasbourg (EOST) et Istanbul Technical University (Dept. of Geology), avec l'octroi d'une bourse d'étude annuelle de !'Ambassade de France à Ankara, une bourse d'excellence EIFFEL de 10 mois, et un support financier de 8 mois de« TUBITAK 22148 - joint Ph.D. ». La zone de convergence de plaques Afrique - Eurasie comporte des failles capables de générer de forts séismes destructeurs. L'objectif de cette thèse est une meilleure compréhension du comportement de ces failles, et du cycle sismique associé, par l'analyse des déformations co-,post- et inter-sismiques enregistrées en surface, dans la zone de convergence. Une attention particulière est portée aux déformations lentes et à leur part dans le cycle sismique, mesurées en surface et analysées à l'aide des techniques lnSAR (Synthetic Aperture Radar lnterferometry), et modélisées par les méthodes de la dislocation élastique<br>This Ph.D. thesis is conducted in the frame of the -co-tutellell scholarship (EOST-ITU) provided by French Embassy in Ankara. ln addition, a 10-month scholarship « Bourse excellence Eiffel » ,and 8-month scholarship « TUBITAK 22148 - joint Ph.D. » were other sources of support for the preparation of this thesis.The convergence between African and Eurasian plates is at the origin of active tectonic structures that generate large and destructive earthquakes. This thesis aims to improve our understanding of fault behavior and the earthquake cycle by analyzing surface deformation along selected active faults during the periods of co-, post-and inter-seismic deformation within the Africa-Eurasia convergence zone. ln this context, slow deformation observed at the surface and associated with the earthquake cycle is analyzed using Synthetic Aperture Radar lnterferometry (lnSAR) time series technique, and modeled with elastic dislocation methods
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Le, Roux-Mallouf Romain. "Déformation Holocène de l’Himalaya du Bhoutan : apport de la géomorphologie et de la paléosismologie." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT142/document.
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La chaîne Himalayenne est l'un des exemples les plus spectaculaires de déformation active à la surface de notre planète. Au cours des derniers siècles, de nombreux séismes majeurs (Mw > 7.5) ont affecté cette zone et le lourd bilan humain du séisme de Gorkha en 2015 a une nouvelle fois rappelé l’importance de parvenir à mieux estimer l’aléa sismique de cette région. Bien que les structures lithologiques et tectoniques semblent montrer au premier ordre une cylindricité le long des 2500 km de l'arc Himalayen, de nombreuses études, menées principalement au Népal, ont permis de mettre en évidence des variations latérales structurales, thermochronologiques, morphologiques, gravimétriques, sismologiques ou géodésiques. Le rôle de ces variations latérales sur la segmentation sismique reste cependant mal contraint. La taille maximale et la probabilité d’occurrence de ces méga-séismes sont donc toujours matière à débat.Ainsi, le comportement sismique de l’Himalaya du Bhoutan reste énigmatique. Pour certains les faibles taux de sismicité observés actuellement font de ce royaume une zone asismique de 350 km de long. Pour d’autres, à l’instar de l’Himalaya du Népal, la faible sismicité observée est associé à une forte accumulation de contrainte susceptible de générer des séismes majeurs. L'objectif de ce travail de thèse est d’améliorer notre connaissance de cette région en quantifiant la déformation à différentes échelles spatiales et temporelles via des études morphotectoniques et paléosismologiques.La première partie de cette thèse vise à quantifier les mouvements verticaux à l’ouest Bhutan et le long du Main Frontal Thrust, structure la plus frontale située au sud Bhoutan. Trois campagnes de terrain ont été réalisées permettant l'échantillonnage (1) de terrasses alluviales le long du front afin de quantifier et d'étudier les variations du soulèvement Holocène, (2) de bassins versants pour l'étude de la dénudation court-terme (< 20 ka) dérivée des cosmonucléides ($^{10}$Be) et (3) de terrasses alluviales dans le Moyen-Pays pour quantifier l’incision Holocène. Les vitesses verticales obtenues au front sont comparables à celle proposées le long du reste de l’arc himalayen, suggérant une cinématique relativement simple. Par contre, nos résultats indiquent une variation de la géométrie du chevauchement himalayen (Main Himalayan Thrust) entre l’est Népal et l’ouest Bhoutan.La seconde partie porte sur plusieurs études paléosismologiques le long du front ouest et centre Bhoutanais. Six sites différents ont été étudiés au cours de trois campagnes de terrain. La datation et la modélisation de charbons détritiques a permis de mettre en évidence l'occurrence d’au moins cinq séismes majeurs durant les derniers 2700 ans, faisant du Bhoutan une zone sismiquement aussi active que le Népal. A une échelle régionale, cette étude apporte donc de nouvelles contraintes et contribue au débat sur la possibilité d’occurrence d'un séisme de magnitude 9 le long de l'arc Himalayen<br>The Himalayan arc is one of the most active intra-continental mountain belts in the world. Over the last centuries, several major earthquakes (Mw > 7.5) have struck this arc. The dramatic effects of the Gorkha earthquake sequence in 2015 pointed once again the crucial need to improve seismic hazard assessment of this area.Geological explorations of the Himalayas since the late 19th century have emphasized a 2500-km-long roughly cylindrical structure, with striking continuity of main units and thrust faults. However recent geophysical and geological investigations have revealed lateral variations. The relationship between these variations and earthquakes segmentation along the arc remains poorly constraint. The maximum size and the occurrence probability of such earthquakes are still a matter of debate.For instance, the seismic behavior of Bhutan remains enigmatic. The present-day low seismicity rate observed in this area can reflect two opposite fault behaviors: an aseismic creeping zone or a zone of stress accumulation for future great earthquakes as the others parts of Himalayas. The main objective of this thesis is to bring new constraints on the deformation of the Bhutan Himalayas, at different space- and time-scales, through morphotectonic and paleoseismological approaches.The first part of this thesis focuses on the vertical deformation assessment along a N-S transect in western Bhutan and along the Main Frontal Thrust, which is the southern-most thrust in southern Bhutan. In the past three years, we have carried out three fieldwork campaigns to sample (1) frontal terraces to assess Holocene uplift rates, (2) watershed basins to quantify short term denudation rates (< 20 ky) derived from cosmonuclides $^{10}$Be and (3) hinterland alluvial terraces to quantify the Holocene incision rate. Frontal Holocene uplift rates obtained in Bhutan are consistent with those obtained in the others parts of Himalayas. Furthermore, our results reveal a variation in the geometry of the Main Himalayan Thrust between eastern Nepal and western Bhutan.The second part focuses on several paleoseismic studies along the west and central bhutanese Himalayan front. Different sites were investigated during three fieldwork campaigns. Detritic charcoals sampling and modeling suggest the occurrence of at least five surface-rupturing earthquakes during the last ~2700 years. These results demonstrate that the present-day low seismicity rate observed in Bhutan is not representative of the seismic activity at longer time scale. At regional scale, they also take part of a broader discussion on the probability of occurrence of a magnitude 9 earthquake along the Himalayan arc
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Zhang, Xiaoliu. "MRI-based active shape model of the human proximal femur using fiducial and secondary landmarks and its validation." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6349.
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Osteoporosis, associated with reduced bone mineral density and structural degeneration, greatly increases the risk of fragility fracture. Magnetic resonance imaging (MRI) has been applied to central skeletal sites including the proximal femur due to its non-ionizing radiation. A major challenge of volumetric bone imaging of the hip is the selection of regions of interest (ROIs) for computation of regional bone measurements. To address this issue, an MRI-based active shape model (ASM) of the human proximal femur is applied to automatically generate ROIs. The challenge in developing the ASM for a complex three-dimensional (3-D) shape lies in determining a large number of anatomically consistent landmarks for a set of training shapes. This thesis proposes a new method of generating the proximal femur ASM, where two types of landmarks, namely fiducial and secondary landmarks, are used. The method consists of—(1) segmentation of the proximal femur bone volume, (2) smoothing the bone surface, (3) drawing fiducial landmark lines on training shapes, (4) drawing secondary landmarks on a reference shape, (5) landmark mesh generation on the reference shape using both fiducial and secondary landmarks, (6) generation of secondary landmarks on other training shapes using the correspondence of fiducial landmarks and an elastic deformation of the landmark mesh, (7) computation of the active shape model. A proximal femur ASM has been developed using hip MR scans of 45 post-menopausal women. The results of secondary landmark generation were visually satisfactory, and no topology violation or notable geometric distortion artifacts were observed. Performance of the method was examined in terms of shape representation errors in a leave-one-out test. The mean and standard deviation of leave-one-out shape representation errors were 0.34mm and 0.09mm respectively. The experimental results suggest that the framework of fiducial and secondary landmarks allows reliable computation of statistical shape models for complex 3-D anatomic structures.
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Li, Run [Verfasser], Gerhard [Gutachter] Gompper, Matthias [Gutachter] Sperl, and Marisol [Gutachter] Ripoll. "Hydrodynamics of colloidal ellipsoids and helices under shear flow and active deformation / Run Li ; Gutachter: Gerhard Gompper, Matthias Sperl, Marisol Ripoll." Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1188810847/34.
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Kasimoglu, Ismail Hakki. "Estimation of a Coronary Vessel Wall Deformation with High-Frequency Ultrasound Elastography." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19762.
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Elastography, which is based on applying pressure and estimating the resulting deformation, involves the forward problem to obtain the strain distributions and inverse problem to construct the elastic distributions consistent with the obtained strains on observation points. This thesis focuses on the former problem whose solution is used as an input to the latter problem. The aim is to provide the inverse problem community with accurate strain estimates of a coronary artery vessel wall. In doing so, a new ultrasonic image-based elastography approach is developed. Because the accuracy and quality of the estimated strain fields depend on the resolution level of the ultrasound image and to date best resolution levels obtained in the literature are not enough to clearly see all boundaries of the artery, one of the main goals is to acquire high-resolution coronary vessel wall ultrasound images at different pressures. For this purpose, first an experimental setup is designed to collect radio frequency (RF) signals, and then image formation algorithm is developed to obtain ultrasound images from the collected signals. To segment the noisy ultrasound images formed, a geodesic active contour-based segmentation algorithm with a novel stopping function that includes local phase of the image is developed. Then, region-based information is added to make the segmentation more robust to noise. Finally, elliptical deformable template is applied so that a priori information regarding the shape of the arteries could be taken into account, resulting in more stable and accurate results. The use of this template also implicitly provides boundary point correspondences from which high-resolution, size-independent, non-rigid and local strain fields of the coronary vessel wall are obtained.
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BRIGHENTI, FABIO. "Data analysis of active geological processes by development of geomatic models - Analisi e sviluppo di modelli geomatici per l’acquisizione di dati provenienti da differenti sistemi geologici attivi." Doctoral thesis, Università degli studi di Catania, 2022. http://hdl.handle.net/20.500.11769/537037.
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This research describes the surface expressions (deformation) of active geological processes linked to certain space-time relationships, localised in central Sicily, through geodetic, geophysical and geological analyses. The surface expressions of active geological processes have been distinguished into two types, those linked to long-term deformation stages of tectonic origin (regional scale) and the transient ones (local scale) linked to deformation processes resulting from the main tectonic dynamics. This research also provides guidelines for monitoring and surveying phenomena consequent to active tectonic processes, formulated according to geological, kinematic and seismological models. These guidelines have been synthesised considering the special characteristics of the individual methodologies and instruments used during this project.
The first part of the thesis introduces the concepts of active geological processes, their monitoring and relief, the study areas (open-air laboratories) being studied by the GEODynamics & GEOMatic Laboratory research group, and the one being studied located in central Sicily (Central Sicily Laboratory). Based on the conceptual model of the Central Sicily Laboratory, the geological, kinematic and seismological models and possible scenarios were defined.
Subsequently, the applied methodologies, the principles on which they are based and their application were introduced. The main objective of the research is to detect and define the surface kinematic behaviour that characterises the study area and consequently define the parameters useful for the development of statistical, analytical and numerical models.
SAR interferometric data were processed, according to the A-DInSAR techniques of Permanent Scatters (PS) by means of StaMPS-MTI to obtain the field deformation of the Laboratory of Central Sicily. GNSS campaigns were also carried out on some sites of the IGM95 network integrated with data from the permanent networks on the Sicilian territory (RING, RDN and TopgeoLive).
The integration between PS and GNSS data makes it possible to define the real velocity field and to validate the velocity field obtained through PS.
In addition, a geodetic topographic (3D) detail analysis was carried out by APR (remotely piloted aircraft) photogrammetry in the area affected by sedimentary volcanism (Maccalube di Santa Barbara, Caltanissetta) to monitor and detect deformations related to mud volcano activity.
The results obtained made it possible to draw up a seismotectonic map of the Laboratory of Central Sicily supported by horizontal and vertical kinematic data and to define guidelines for monitoring geological processes in areas affected by active tectonics.
Finally, areas have been identified in which the acting dynamics need to be investigated with further studies, such as areas affected by interseismic disequilibrium (Hyblean Plateau), areas in which phenomena of decoupling of regional deep and local surface deformation processes are detected (western slopes of Etna), and areas that bear witness to uplift of tectonic origin (south-western area of western Sicily.
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Ibarra, Federico [Verfasser], Manfred R. [Akademischer Betreuer] Strecker, and Magdalena [Akademischer Betreuer] Scheck-Wenderoth. "The thermal and rheological state of the Central Andes and its relationship to active deformation processes / Federico Ibarra ; Manfred R. Strecker, Magdalena Scheck-Wenderoth." Potsdam : Universität Potsdam, 2021. http://d-nb.info/1234058758/34.
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Stockmeyer, Joseph M. "Active deformation over multiple earthquake cycles in the southern Junggar fold and-thrust belt, NW China and fractured reservoir characterization using 3D geomechanical restorations." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493253.
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This dissertation investigates natural deformation processes over multiple earthquake cycles in the seismically active, southern Junggar basin, NW China and additionally explores the capabilities of 3D geomechanical restoration as an effective tool for fractured reservoir characterization. Chapter 1 presents a detailed 3D fault model of the active Southern Junggar Thrust (SJT) – constrained by seismic reflection data – in the southern Junggar basin. This work demonstrates the significance of mid-crustal detachments as a physical mechanism to accommodate destructive, multi-segment earthquakes in active thrust sheets. Moreover, it highlights the efficacy of surface folds to delineate fault geometries at depth in the absence of subsurface data constraints. Chapter 2 describes active thrust sheet deformation across the Tugulu anticline, which sits in the hanging wall of the SJT, from Late Quaternary to present. Holocene terrace deformation records of surface faulting and folding yield consistent fault slip rates. We develop a quantitative method for extracting fault slip rates from terrace fold geometries using a mechanical modeling approach, yielding a 250 kyr history of SJT slip. This study provides new insights into natural fold growth associated with fault slip. Moreover, it addresses several shortcomings of traditional seismic hazards assessment methodologies. Chapter 3 characterizes the styles, timing, and sequence of deformation across southern Junggar. Southern Junggar underwent extension followed by tectonic inversion and shortening, forming a series of imbricate structural wedges. A kinematic model for the evolution of shear fault-bend fold wedges is presented. We discuss the implications of structural style, fold growth and thrusting sequence on the ~175 Myr evolution of this fold-and-thrust belt and its petroleum system. Chapter 4 investigates the impact of natural fold strains on fractured reservoir properties in the Permian Basin, West Texas. This study details the ability of 3D geomechanical restorations to accurately model natural strain distributions associated with fold growth. Modeled strains from geomechanical restorations are integrated with proxies for natural deformation and production data to describe how tectonic strain impacted observed gas production, water cuts and reservoir temperatures. When used in conjunction with additional datasets, geomechanical restoration shows promise for predictive abilities in characterizing conventional and unconventional fractured reservoir properties.<br>Earth and Planetary Sciences
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Kim, Haeng Yoong. "Characteristic Behaviors and Structural Segmentation of Active Faults as Accumulative Deformation of Tectonic Landform along the Shinano River Fold and Thrust zone, central Japan." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/148361.
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Lienhard, Julian [Verfasser], and Jan [Akademischer Betreuer] Knippers. "Bending-active structures : form-finding strategies using elastic deformation in static and kinetic systems and the structural potentials therein / Julian Lienhard. Betreuer: Jan Knippers." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2014. http://d-nb.info/1055944583/34.
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VanderBeek, Brandon. "New Perspectives on Mid-Ocean Ridge Magmatic Systems and Deformation in the Uppermost Oceanic Mantle from Active- and Passive-Source Seismic Imaging in Cascadia." Thesis, University of Oregon, 2019. http://hdl.handle.net/1794/24205.
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In this dissertation, I use seismic imaging methods to constrain the evolution of the oceanic upper mantle across the Juan de Fuca (JdF) and Gorda plates. This work begins by studying the geometry of the mantle magmatic system and patterns of mantle flow beneath the northern JdF ridge in relation to ridge-parallel changes in accretionary processes. I find that the dynamics of lithospheric rifting exert the primary control on the distribution of shallow mantle melts and variations in crustal thickness and composition. The orientation of mantle divergence beneath the JdF ridge, as inferred from seismic anisotropy, is oblique to the overlying plate divergence direction. Similar observations made at the East Pacific Rise and Mid-Atlantic ridge suggest plate motions alone do not control mantle flow patterns. On the contrary, stresses exerted at the base of the plate by the asthenospheric flow field may contribute to changes in plate motion prompting a reorientation of oceanic spreading segments. The mantle anisotropic fabric of the JdF plate interior is then investigated to identify whether the rotated mantle flow field observed beneath the JdF ridge persisted throughout the recent geologic past. However, observations suggest that the anisotropic structure created at the ridge partially reorganizes off-axis obscuring the paleo-flow geometry. Next, I focus on how the physical state of the oceanic lithosphere evolves with time. Using local earthquake arrival times I test whether the seismic velocity structure of the upper mantle lithosphere is thermally controlled or dominated by heterogeneities introduced upon accretion at the ridge or by subsequent deformation off axis. Despite extensive surficial evidence of faulting across the Gorda plate, deformation appears to be restricted to crustal depths and mantle velocities are explained by conductive cooling. In contrast, the velocity structure of the JdF plate is inconsistent with conductively-cooled mantle. Hydration of the mantle lithosphere associated with tectonic discontinuities is invoked to explain anomalously slow P-wave speeds. Lastly, a joint inversion of teleseismic body and surface wave data is proposed to image the geometry of mantle upwelling and melt production beneath the JdF and Gorda Ridges.
This dissertation includes previously published and unpublished coauthored material.
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Teshebaeva, Kanayim [Verfasser], and Helmut [Akademischer Betreuer] Echtler. "SAR interferometry analysis of surface processes in the Pamir – Tien Shan active orogens - emphasis on coseismic deformation and landslides / Kanayim Teshebaeva ; Betreuer: Helmut Peter Echtler." Potsdam : Universität Potsdam, 2016. http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96743.
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Teshebaeva, Kanayim [Verfasser], and Helmut Peter [Akademischer Betreuer] Echtler. "SAR interferometry analysis of surface processes in the Pamir – Tien Shan active orogens - emphasis on coseismic deformation and landslides / Kanayim Teshebaeva ; Betreuer: Helmut Peter Echtler." Potsdam : Universität Potsdam, 2016. http://d-nb.info/1218400927/34.
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van, der Wal Jorien Leonorah Ninon Verfasser], Klaus [Akademischer Betreuer] [Reicherter, and Frank [Akademischer Betreuer] Lehmkuhl. "Active tectonics of a slowly deforming continental interior : Deformation and quaternary landscape evolution in southern Mongolia / Jorien Leonorah Ninon van der Wal ; Klaus Reicherter, Frank Lehmkuhl." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1241891486/34.
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VIČIČ, BLAŽ. "High resolution earthquake relocation along Idrija fault system in Western Slovenia and its application in understanding the deformation along the active faults of NW External Dinarides." Doctoral thesis, Università degli Studi di Trieste, 2018. http://hdl.handle.net/11368/2922574.
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Northeastern Italy and Western Slovenia lies in the region of moderate earthquake activity.
In the past, rare strong earthquakes struck the region, namely 1511 Idrija M 6.9, Friuli 1976
series of M 6+ and 1998 and 2004 M 5.6 and 5.2 Ravne fault earthquakes. Multiple geodetic, geomorphologic and geologic studies show, that IFS is an active fault system, with slip rates up to 3.8 mm/yr over all the faults.
Since 2006 area of IFS is covered by relatively dense network of broadband stations recording in continuous mode. To better understand the IFS itself, a detailed seismologic study was performed in this study.
To gain the knowledge of fault system geometry, physics of faulting and temporal behavior, the data of all the stations in the region was analyzed. First, time series were analyzed using classic STA/LTA detection algorithm for the detection of earthquakes. After the initial scan of the database, arrival times of phases of detected earthquakes were manually repicked to obtain as precise arrival times of phases as possible. The magnitude of completeness for the catalog obtained in such way was 0.9. To obtain lower magnitude of completeness, additional manual inspection of waveforms was performed. New micro earthquakes were added to the existing database.
For the detection of even lower magnitude earthquakes, all the earthquakes of magnitudes above 0.8 were selected as a template earthquakes. Matched filter detection of earthquakes was performed on the selected stations with simultaneous picking of precise phases as obtained from cross correlation around the P or S arrival times between template earthquake and the detected earthquake. The newly obtained earthquakes were added to the database lowering the magnitude of completeness to -0.7.
Manually relocated earthquakes and earthquakes obtained from matched filter detection clearly illuminated active faults of IFS, showing activity along all the faults of the system. From cross sections perpendicular to the IFS clear geometry was defined for the central part of the system. Cross section showed that earthquakes along Ravne fault are much more shallow than on other faults of the system and illuminate a SW dipping fault which probably connects to Idrija fault at depth. Idrija fault was only active in its northern extend in the analyzed period, with deeper earthquakes illuminating vertical fault plane. Predjama and Selce fault were mostly active in the central and southern part of the system. Earthquakes along these two faults show vertically dipping faults. Finally, earthquake activity along Raša fault is mostly present in its central and southern extend and show a fault plane dipping towards NE.
High resolution detection of the earthquakes also gave a better understanding of temporal earthquake evolution along the IFS. Temporal clustering was observed in the years 2009-2010 and in the late 2017. In 2009-2010 majority of the system shows high activity, with swarms taking place in northern and central part of the system and multiple mainshock-aftershock series in southern part. Similar, in 2017 multiple swarms and mainshock series happened in the southern part of the system.
Combining the detected temporal clustering with the datasets of extensometer mounted on Predjama fault we observed that in the same time period as the 2009-2010 elevated activity happened, also a surface deformation was present. We modeled the surface deformation and earthquake activity using Coulomb stress changes. Best fit was given to the changes of normal stresses along the Idrija fault, which led to the unclamping of the faults parallel to Idrija fault, increasing the earthquake rates along these faults and causing the surface deformations due to the extraction and migration of fluids at depth.
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Amokrane, Mounir. "Étude et mise en œuvre de couplage thermoélectrique en vue de l'intensification d'échange de chaleur par morphing électroactif." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/11499/1/amokrane_partie_1_2.pdf.
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Le développement et l’utilisation de nouveaux matériaux, tel que le carbure de silicium (SiC) et le nitrure de gallium (GaN), a permis un accroissement sensible des densités d’énergie traitées par les nouveaux composants de l’électronique de puissance, assortie d’une augmentation de leur compacité. Parallèlement à ces progrès technologiques, la généralisation de l’électricité en tant que vecteur d’énergie primaire au sein de systèmes de plus en plus répartis, incluant des moyens de traitement de l’information au plus près de la fonction réalisée, ouvre la voie à une nouvelle génération de systèmes mécatroniques hautement intégrés. Or, l’émergence de ces nouvelles fonctions soulève une question critique liée au mode de refroidissement de ces éléments. Cette question est intimement couplée aux aspects énergétiques et à leur impact environnemental, imposant une amélioration significative des rendements énergétiques mesurés à l’échelle de la fonction complète. C’est dans ce contexte que l’étude présentée traite tout d’abord de systèmes de récupération de la chaleur résiduelle dissipée au sein de systèmes électroniques de puissance en vue d’alimenter de manière autonome des capteurs, où autres systèmes fonctionnels, via l’énergie « ambiante » ainsi récupérée. Parmi les consommateurs plus particulièrement ciblés, des fonctions innovantes d’intensification par voie électromécanique des échanges de chaleurs au sein d’échangeurs thermique sont étudiées et mises en œuvre. A terme, l’idée serait ainsi d’alimenter les systèmes d’actionnement assurant l’optimisation des échanges de chaleur au sein du système de refroidissement d’une carte électronique au moyen même de la chaleur qu’elle dissipe, récupérée sous forme d’énergie électrique. A cette fin, les différents procédés de conversion de la chaleur en électricité sont examinés, modélisés et mis en œuvre dans la suite de ce travail. Deux types de conversion d’énergie complémentaires sont tour à tour considérés : La conversion par effet thermoélectrique, utilisant l’effet Seebeck qui a lieu en présence d’un gradient de température et l’effet pyroélectrique qui apparait en présence de variation temporelle de la température. Ces deux phénomènes sont analysés et décrits à l’aide de modélisations physiques et comportementales, incluant une approche expérimentale ayant nécessité la mise en place de bancs d’essai spécifiques. L’électricité récupérée par conversion pyroélectrique est par la suite mise en forme grâce à des systèmes de redressement à faible tension de seuil spécialement développés. La faisabilité de systèmes d’alimentation autonomes de capteurs déportés, où de systèmes d’émission (ponctuelle) de mesure, est alors concrètement démontrée en se basant sur les résultats obtenus. Ouvrant la voie à un concept de refroidissement actif des puces électroniques, tirant directement parti de la chaleur dissipée pour son alimentation grâce aux deux procédés préalablement étudiés, la problématique de l’intensification des transferts de chaleur au sein de boucles de refroidissement mécaniquement activées est abordée dans la dernière partie du mémoire. Cette activation est réalisée à l’aide d’un système d’actionnement multicellulaire réparti à base d’actionneurs piézoélectriques. Développée en étroite collaboration avec des équipes de thermodynamiciens, l’idée est de réaliser un pompage de fluide ainsi qu’une modification des échanges de chaleur au sein d’un système de transfert de chaleur en activant les parois de l’échangeur de chaleur par déformation. Le système d’actionnement préconisé est tout d’abord étudié et simulé par un calcul par éléments finis. Un prototype est construit et caractérisé sous conditions réelles dans un deuxième temps. Le système d’actionnement multicellulaire composé d’un ensemble d’actionneurs et d’un système d’alimentation paramétrable multivoies est alors intégré au sein d’un banc d’essai d’échange de chaleur spécifiquement développé. Cette expérience constitue une première étape fondamentale dans la mise au point de systèmes électroactifs, potentiellement autonomes, permettant l’intensification des échanges de chaleur au sein de boucles de refroidissement à haute performance destiné à l’électronique de puissance.
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Benavente, Escobar Carlos Lenin. "Neogene tectonic and exhumation of the Andes Centrales, Southern Peru." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAU021/document.
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L’histoire et les mécanismes de soulèvement des Andes centrales ont fait l'objet de débats animés depuis les années 1970. Notre étude se concentre sur l’analyse de la déformation Cénozoïque et de l'exhumation des Andes Centrales dans la région du Sud Pérou : à Cuzco, et dans la région de Nazca entre les cordillères Occidentale et Côtière. En effet, plusieurs auteurs soulignent le rôle du raccourcissement tectonique dans l'épaississement de la croûte, dans l’avant-arc Chilien ou à l’Est dans la région Subandine. Dans les modèles de déformation tectonique active issus du GPS, aucun raccourcissement ni transpression n’est pris en compte sur la bordure Occidentale des Andes au Cénozoïque ou dans les modèles de déformation crustale issus du GPS. La nouvelle cartographie des systèmes de failles actives dans la région sud du Pérou donnent un aperçu de la déformation active à l’échelle crustale pour la marge Pacifique des Andes Centrales. La géomorphologie et les paysages de l'avant-arc andin ont classiquement été présentés comme fossiles depuis le Miocène, sans évidence de structures actives accommodant la déformation cénozoïque. Cependant, les surfaces géomorphologiques bien préservées développées dans l'avant-arc du sud du Pérou fournissent d'excellents marqueurs et des évidences de déformation très nettes depuis le Cénozoïque jusqu’au Quaternaire récent. Ces marqueurs montrent tous un soulèvement des Andes le long de la marge ouest depuis les derniers Millions d’années. Bien que l’initiation et l’évolution de l'exhumation et du soulèvement cénozoïque aient été étudié dans les canyons de Colca et de Cotahuasi, il demeure peu contraint dans le segment nord de l'avant – arc, i.e., dans la région de Nazca. Dans cette étude, nous avons choisi d’apporter de nouvelles données (U-Th)/He et traces de fission sur apatite (AHe) et (AFT) respectivement dans cette région. L’échantillonnage a porté sur la Cordillère Occidentale entre Cañete et Nazca le long de deux nouvelles coupes transversales à la topographie. Le profil Age/Distance à la côte indique une mise en place de relief dans la région Andine au début du Miocène et une évolution découplée des deux systèmes de cordillères Cotière et Occidentale en terme d’exhumation dans le temps. A l’échelle Quaternaire, nous avons cartographié les failles actives pour déterminer leur géométrie, cinématique et les âges maximaux de l’activation de ces failles. Ceci afin de discuter du rôle de cette activité tectonique, précédemment supposée Miocène, dans le soulèvement et l’exhumation de l’avant-arc Andin. Nous avons utilisé la production et l’accumulation du 10Be cosmogénique dans les roches pour déterminer les âges d'exposition d’un escarpement tectonique marquant les derniers épisodes co-sismiques de la faille de Purgatorio. Nos nouveaux résultats, contrastent avec des conclusions précédentes qui concluaient à de l’extension et des vitesses lentes le long de l’avant arc Andin (<0.1mm/an). Les âges très récents indiquent une morphologie « historique » (free face) et deux tremblements de terre Mw6-7 sur ce système de failles transpressives qui se connectent au système principal d’Incapuquio. Les données suggèrent non seulement une déformation active significative de l’avant-arc, mais soulignent aussi l’existence d’un aléa sismique qui n’est toujours pas pris en compte pour les failles crustales dans les Andes. Tandis que l’hypothèse acceptée est que la déformation active est localisée dans le bassin d’avant pays subandin, ou à l’est de la cordillère orientale, nos données suggèrent qu’une partie de la déformation active se localise aussi sur la marge Occidentale ainsi que le long de la faille d'Incapuquio. De plus, les failles observées en néotectonique accommoderaient le partitionnement de la déformation le long de la subduction oblique et ceci n’a jamais été discuté précédemment. Ce mouvement, rigide, en bloc serait du à la présence du craton accrété sur le flanc Ouest et à sa rigidité<br>ABSTRACTTiming and mechanisms of uplift in the Central Andes have been a matter of debate since at least the 1970’s. Our study focuses on Cenozoic deformation and exhumation of the Central Andean forearc in Peru, in Cuzco region, and between the Western Cordillera and the Coastal Cordillera in Nazca region. Our new mapping of active faults provides new insights into the Cenozoic to present-day crustal deformation of the Central Andean Western margin. Until now, apart from some local studies, the geomorphology of the Andean forearc has classically been presented as a remnant Miocene landscape with no significant active structures accommodating the Cenozoic deformation. Thanks to new high-resolution optical imagery, the well-preserved geomorphic surfaces developed within the forearc of southern Peru provide excellent regional markers to map patterns of deformation. Pertaining to the Cenozoic history, while the timing of uplift-related exhumation and Cenozoic exhumation has been studied in Colca and Cotahuasi canyons, it remain poorly constrained in the northern segment of the Central Andean forearc. I report new apatite (U–Th)/He (AHe) and fission track (AFT) ages from the western Cordillera between Cañete and Nazca along two new cross sections. The ages in Nazca region reflect relatively recent (since ~10Ma) relief creation along the western margin of the Altiplano, similar to what is described south in Colca region.The Quaternary tectonic history is revealed by the newly mapped fault segments affecting the Miocene deposits within forearc. Through field and remote mapping, I determined fault geometries and maximum ages for the activity of the faults systems based on stratigraphic relationships in order to assess the role of this tectonic activity in the Western Cordillera uplift and exhumation.To understand the Holocene tectonic history, we use in situ produced 10Be to determine the exposure ages of the free face and tectonic scarp of the Purgatorio Fault in order to map the temporal evolution of its seismotectonic activity. Our new results display evidence of transpression and the formation of meter-high coseismic scarps as well as very recent exposure ages indicating a youthful fault morphology and Mw6-7 earthquakes occurring along the Purgatorio fault segments. These new data are in contrast with some previous conclusions for this region which suggest extension and/or slow rates of deformation for this region and time period. Further, these new data not only suggest significant active deformation within the forearc, but also highlight a potential seismic hazard for the region that not take into account crustal forearc faults.While the general assumption is that active deformation is localized in the Subandean fold and thrust belt, or east of the Western Cordillera in the Altiplano, our data support a model where active deformation is occurring in the western margin as well, along the Incapuquio Fault and other neotectonic faults that accommodates the partitioning of the subduction oblique convergence.These crustal active faults and more precisely the “not migrating to the trench” Incapuquio fault zone reveal the rigid motion of the forearc. Our new model is nevertheless compatible with the recently published GPS data that measure a southeastward movement at 4–5 mm/yr relative to a stable South America reference frame. This rigid motion is in part due to the presence of the rigid Greenvillian accreted craton, that behave as a sliver, and rather tilt than deform through time
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Duffy, Brendan Gilbert. "Development of Multichannel Analysis of Surface Waves (MASW) for Characterising the Internal Structure of Active Fault Zones as a Predictive Method of Identifying the Distribution of Ground Deformation." Thesis, University of Canterbury. Geological Sciences, 2008. http://hdl.handle.net/10092/2051.
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Bulk rock strength is greatly dependent on fracture density, so that reductions in rock strength associated with faulting and fracturing should be reflected by reduced shear coupling and hence S-wave velocity. This study is carried out along the Canterbury rangefront and in Otago. Both lie within the broader plate boundary deformation zone in the South Island of New Zealand. Therefore built structures are often, , located in areas where there are undetected or poorly defined faults with associated rock strength reduction. Where structures are sited near to, or across, such faults or fault-zones, they may sustain both shaking and ground deformation damage during an earthquake. Within this zone, management of seismic hazards needs to be based on accurate identification of the potential fault damage zone including the likely width of off-plane deformation. Lateral S-wave velocity variability provides one method of imaging and locating damage zones and off-plane deformation. This research demonstrates the utility of Multi-Channel Analysis of Surface Waves (MASW) to aid land-use planning in such fault-prone settings. Fundamentally, MASW uses surface wave dispersive characteristics to model a near surface profile of S-wave velocity variability as a proxy for bulk rock strength. The technique can aid fault-zone planning not only by locating and defining the extent of fault-zones, but also by defining within-zone variability that is readily correlated with measurable rock properties applicable to both foundation design and the distribution of surface deformation. The calibration sites presented here have well defined field relationships and known fault-zone exposure close to potential MASW survey sites. They were selected to represent a range of progressively softer lithologies from intact and fractured Torlesse Group basement hard rock (Dalethorpe) through softer Tertiary cover sediments (Boby’s Creek) and Quaternary gravels. This facilitated initial calibration of fracture intensity at a high-velocity-contrast site followed by exploration of the limits of shear zone resolution at lower velocity contrasts. Site models were constructed in AutoCAD in order to demonstrate spatial correlations between S-wave velocity and fault zone features. Site geology was incorporated in the models, along with geomorphology, river profiles, scanline locations and crosshole velocity measurement locations. Spatial data were recorded using a total-station survey. The interpreted MASW survey results are presented as two dimensional snapshot cross-sections of the three dimensional calibration-site models. These show strong correlations between MASW survey velocities and site geology, geomorphology, fluvial profiles and geotechnical parameters and observations. Correlations are particularly pronounced where high velocity contrasts exist, whilst weaker correlations are demonstrated in softer lithologies. Geomorphic correlations suggest that off-plane deformation can be imaged and interpreted in the presence of suitable topographic survey data. A promising new approach to in situ and laboratory soft-rock material and mass characterisation is also presented using a Ramset nail gun. Geotechnical investigations typically involve outcrop and laboratory scale determination of rock mass and material properties such as fracture density and unconfined compressive strength (UCS). This multi-scale approach is espoused by this study, with geotechnical and S-wave velocity data presented at multiple scales, from survey scale sonic velocity measurements, through outcrop scale scanline and crosshole sonic velocity measurements to laboratory scale property determination and sonic velocity measurements. S-wave velocities invariably increased with decreasing scale. These scaling relationships and strategies for dealing with them are investigated and presented. Finally, the MASW technique is applied to a concealed fault on the Taieri Ridge in Macraes Flat, Central Otago. Here, high velocity Otago Schist is faulted against low velocity sheared Tertiary and Quaternary sediments. This site highlights the structural sensitivity of the technique by apparently constraining the location of the principal fault, which had been ambiguous after standard processing of the seismic reflection data. Processing of the Taieri Ridge dataset has further led to the proposal of a novel surface wave imaging technique termed Swept Frequency Imaging (SFI). This inchoate technique apparently images the detailed structure of the fault-zone, and is in agreement with the conventionally-determined fault location and an existing partial trench. Overall, the results are promising and are expected to be supported by further trenching in the near future.
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Cáceres, Calix Diego José. "Earthquake Sources and Hazard in northern Central America." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3389.
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<p>Northern Central America is a tectonically complex zone defined by its borders with Cocos and North America plates. The Middle America subduction zone and the strike-slip motion along the North America-Caribbean plate boundary, in that order, control most of its deformation. The interaction between the different elements of the studied area is evident from the high seismicity in the region, especially along plate boundaries. Also in the interior of the region, seismicity shows that deformation takes place, though in lesser degree. In a time window of 30 years, three earthquakes with moment magnitude larger than 7 struck northern Central America evincing the need to estimate the seismic hazard for the zone. To tackle the problem, we compiled a catalogue of hypocenters commencing in 1964, defined seismogenic sources and described the evolution of earthquake activity through a Poisson model. Probabilistic seismic hazard (PSH) calculations for the next 50 years were performed. The highest estimate of seismic hazard was obtained for the zone adjacent to the subduction zone. Because of the fundamental importance of demarcating seismogenic sources in the PSH analysis, i.e. defining the seismotectonic model, we extended the catalogue to cover 102 years for the whole northern Central America. We have studied the North America-Caribbean plate boundary in order to refine the fault representation. Different techniques were used, like that of body-waveform modeling, allowing us to limit the extent of depth of faulting to 20 km. The seismic moment tensor was used to estimate the deformation velocities on known tectonic structures, including those of the Honduras depression and borderland faults. Finally, we made use of the Coulomb stress criterion to determine the relation between earthquake occurrence and static stress changes following major earthquakes.</p>
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Souza, Franciane Colares 1979. "Efeito da atmosfera modificada e da variação de temperatura durante armazenagem na qualidade do figo "roxo de Valinhos"." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257047.
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Orientador: Antonio Carlos de Oliveira Ferraz<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola<br>Made available in DSpace on 2018-08-11T01:53:24Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007<br>Resumo: A cultura do figo (Ficus carica L.) no estado de São Paulo iniciou-se no começo do século XX na região de Campinas e Valinhos, e desde 1990 vem ganhando destaque na região, responsável por 90% da produção nacional de figos de mesa, e tem conseguido espaço no mercado europeu no período de entressafra. O figo 'Roxo de Valinhos' é altamente perecível, com curta vida útil em condições ambientais, de 1 a 3 dias, razão pela qual deve ser comercializado rapidamente. Como não são aplicadas técnicas para conservação do figo, para que chegue em condição aceitável na Europa, a solução encontrada pelos produtores foi antecipar sua colheita, colhendo-o no estádio verde, bem mais cedo que o utilizado para o figo destinado ao mercado interno, prejudicando seu sabor e aparência. O objetivo deste trabalho foi avaliar o desempenho da atmosfera modificada ativa na qualidade e vida útil do figo 'Roxo de Valinhos¿. Utilizou-se o figo no estádio meio maduro (rami), armazenado com atmosfera modificada passiva (AMP) e atmosfera modificada ativa (AMA) com 20% de CO2 e 6,5% de O2, acondicionado em filme de polietileno de baixa densidade (PEBD) de 30µm, e armazenado durante uma semana sob quatro regimes térmicos (RT), com umidade relativa de 90±5%. Os RT avaliados foram temperatura constante de 20ºC±1ºC (RT1), temperatura constante de 10ºC±1ºC (RT2), temperatura de 20ºC±1ºC nas primeiras 48 horas de armazenamento seguida de um degrau negativo de 10ºC a partir o terceiro dia (RT3) e temperatura de 10ºC±1ºC no primeiro dia de armazenamento, seguidas por um degrau positivo de 10ºC no segundo dia, com diminuição para 10ºC do terceiro dia até o final do armazenamento (RT4). Para avaliação do desempenho das condições de atmosfera e regimes térmicos na qualidade do figo foram realizadas medidas de temperatura da polpa do figo, concentração gasosa nas embalagens (CO2, O2 e etileno), perda de massa, sólidos solúveis, acidez titulável, firmeza de polpa e aparência. As embalagens com AMA não mantiveram a concentração inicial de CO2 em 20%, devido à alta taxa de permeabilidade do filme a esse gás. A partir do quarto dia, a concentração de CO2 apresentou tendência de equilíbrio para os tratamentos com AMP e AMA, sem alterações significativas até o final do armazenamento. Os tratamentos com AMP e AMA mantiveram baixos índices de perda de massa, próximos a 1,5%, boa aparência e melhores índices de firmeza até o final do armazenamento, enquanto as frutas do tratamento testemunha não apresentaram condições de comercialização a partir do quarto dia. Foi evidenciado que o RT1 apresentou a pior condição para armazenamento do figo, favorecendo a perda de massa e ocorrência de podridão das frutas, e não foi observada diferença entre as frutas armazenadas com AMP e AMA<br>Abstract: The production fig (Ficus carica L.) began in the state of São Paulo at the beginning of XX century in the area of Campinas and Valinhos, and since 1990 this production is getting prominence as responsible for 90% of the national production of fresh figs, including exports to Europe. The ' Roxo of Valinhos' fig is highly perishable, lasting 1 to 3 days in room conditions, and therefore it shall be marketed quickly. Since conservation techniques are not usually applied in figs, the solution found by the producers for the product arrive in acceptable condition in Europe was to anticipate harvest, picking it in the green stadium, much earlier than used for the fig destined to the internal market, harming its flavor and appearance. The objective of this work was to evaluate the effect of an active modified atmosphere in quality and shelf life of the 'Roxo of Valinhos' fig. Figs were harvested at the middle stadium of ripening, stored with passive modified atmosphere and active modified atmosphere (20%CO2 and 6,5%O2), wrapped with low density 30µm polyethylene film (LDPE), and stored during one week under four thermal regimes (RT), with relative humidity of 90±5%. Thermal regimes (TR) used were constant temperature of 20ºC±1ºC (TR1), constant temperature of 10ºC±1ºC (TR2), temperature of 20ºC±1ºC in the first 48 hours of storage followed by a negative step of 10ºC in the third day (TR3) and temperature of 10ºC±1ºC in the first day of storage, followed for a positive step of 10ºC in the second day, with decrease for 10ºC of the third day to the end of the storage (TR4). For evaluation of the performance of the combination of atmosphere conditions and thermal regimes in the quality of the fig, there were performed measurements of pulp temperature, gaseous concentration in the packages (CO2, O2 and C2H4), weight loss, soluble solids, titritable acidity, pulp firmness and appearance. The packages with active modified atmosphere didn't maintain the initial concentration of CO2, due to the high diffusion rate of the film to that gas CO2 concentration achieved equilibrium at the fourth day for both of the treatments with passive and active modified atmosphere, without significant changes until the end of storage period. The treatments with modified atmosphere showed low indexes of weight loss, good appearance and little changes in firmness index till the end of storage, while the fruits of the control treatment didn't present marketable conditions at the fourth day. TR1 resulted in worst condition for storage of the fig, favoring weight loss and decay occurrence. No difference was observed among fruits stored with active and passive modified atmosphere<br>Mestrado<br>Tecnologia Pós-Colheita<br>Mestre em Engenharia Agrícola
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Lavi, Ido. "Physical modeling of cell motility and morphodynamics." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS237.
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Cette thèse introduit un modèle hydrodynamique minimal de polarisation, migration et déformation d'une cellule vivante confinée entre deux surfaces parallèles. Le cytoplasme cellulaire, décrit comme une goutte visqueuse, est entraîné par une force active contrôlée par un soluté diffusif. Une analyse de stabilité linéaire révèle que l'activité du soluté déstabilise d'abord un mode global de polarisation et de translation, induisant une motilité cellulaire par rupture spontanée de symétrie. Pour une activité plus grande, le système traverse une série de bifurcations de Hopf conduisant à des oscillations couplées de la forme de la goutte et de la concentration de soluté. Nous trouvons également des solutions non linéaires de type onde progressive associées à des formes polarisées ressemblant à des observations expérimentales. De plus, nous avons développé des simulations numériques de ce problème basées sur la méthode des éléments finis. L'étude numérique a mis en évidence la stabilité des solutions de type onde progressive, l’existence d’attracteurs oscillants et l’apparition d’une singularité du bord à temps fini. En intégrant des interactions mécaniques avec l'environnement extérieur, nous avons exploré la diffusion cellulaire en présence de parois et d'obstacles stationnaires, la migration à travers des micro-géométries imposées et les collisions cellule-cellule. Ces simulations ont capturé une gamme de motifs non triviaux résultant de la mémoire intrinsèque et de la déformabilité de la cellule. Globalement, notre étude fournit un paradigme mathématique de systèmes actifs déformables qui couplent l'hydrodynamique de Stokes à des transducteurs de force diffusifs<br>This thesis introduces a minimal hydrodynamic model of polarization, migration, and deformation of a biological cell confined between two parallel surfaces. Our model describes the cell cytoplasm as a viscous droplet that is driven by an active cytoskeleton force, itself controlled by a diffusive cytoplasmic solute. A linear stability analysis of this two-dimensional system reveals that solute activity first destabilizes a global polarization-translation mode, prompting cell motility through spontaneous-symmetry-breaking. At higher activity, the system crosses a series of Hopf bifurcations leading to coupled oscillations of droplet shape and solute concentration profiles. At the nonlinear level, we find traveling-wave solutions associated with unique polarized shapes that resemble experimental observations. In addition, we developed a numerical simulation of our moving-boundary problem based on the finite element method. The numerical study demonstrated the stability of our traveling-wave solutions, the existence of sustained oscillatory attractors, and the emergence of a finite-time pinch-off singularity. By incorporating mechanical interactions with the external environment, we explored cell scattering from stationary walls and obstacles, migration through imposed micro-geometries, and cell-cell collisions. These exercises capture a range of nontrivial patterns resulting from the intrinsic memory and deformability of the cell. Altogether, our work offers a mathematical paradigm of active deformable systems in which Stokes hydrodynamics are coupled to diffusive force-transducers
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Alvarado, cevallos Alexandra patricia. "Néotectonique et cinématique de la déformation continentale en Equateur." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00870332.
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Situé dans le contexte d'une subduction rapide, (vitesse de convergence de 6-8 cm/an), l'Equateur est particulièrement exposé au risque sismique. La composante de la sismicité qui est directement attribuée au processus de subduction est depuis quelques années l'objet de nombreuses études, mais la sismicité "indirecte" due aux processus de déformation dans la plaque supérieure reste peu étudiée. Pourtant, les populations sont directement exposées à cette séismicité intracontinentale, qui reste dangereuse en raison de sa faible profondeur et distance aux zones densément peuplées.Le premier objectif de cette thèse est l'étude de la cinématique régionale, dominée par la présence d'un grand système de failles continentales décrochantes qui s'étend depuis la marge active (Golfe de Guayaquil) jusqu'à la frontière Colombienne. De nombreuses failles associées au processus d'extrusion du Bloc Nord Andin montrent une trace géomorphologique très nette mais ne sont pourtant pas cartées car les accès terrain ne permettent pas de conclure sur leur activité. L'analyse des photos aériennes, d'images satellite et de MNT à différentes échelles nous a permis d'établir tout d'abord un catalogue tectonique des structures majeures, homogène et systématique, puis de déterminer la cinématique de la plupart des structures actives en Equateur à l'échelle Quaternaire. De plus, nous avons intégré l'information sismologique (sismicité et mécanismes au foyer) et géodésique disponible à partir des réseaux nationaux de l'Equateur. Ceci nous a permis d'apporter des contraintes cinématiques sur le fonctionnement de ces structures et comparer les processus de déformation instantanés et cumulés à l'échelle du Quaternaire. Le système tectonique majeur d'Equateur Chingual-Cosanga-Pallatanga-Puná (CCPP) montre une vitesse moyenne de 7 à 8 mm/an par rapport à Sud Amérique. Les structures qui le définissent sont principalement transpressives dextres, avec une distribution nette de la composante décrochant sur les failles de direction NE-SW, et de la composante inverse sur les structures plutôt NS. Ce système tectonique majeur permet l'extrusion vers le nord du Bloc Nord-Andin. Notre interprétation implique l'existence et la définition d'un nouveau microbloc, isolé sur le flanc Ouest de la structure CCPP, qui est limité à l'ouest par les systèmes chevauchants de Quito et Latacunga, et à l'est par les failles du système Chingual Cosanga, depuis environ 3 Ma.Dans un deuxième temps, l'analyse des marqueurs morphologiques de la déformation et de l'évolution des réseaux de drainage associée à un travail de détail sur le terrain et de datations nous ont permis d'étudier cette deuxième région particulière des Andes d'Equateur. Le système de chevauchements de Quito est formé par des failles inverses aveugles qui produisent en surface une série de plis en échelon à vergence Ouest dans les dépôts volcaniques Quaternaire. Cette cinématique est confirmée par l'analyse de la sismicité superficielle et locale, et les mécanismes au foyer issus du réseau national RENSIG. Les données GPS montrent un taux de raccourcissement EW de 4 mm/an, accommodé sur cette structure compressive particulièrement active à l'échelle régionale. En profondeur le système de faille de Quito se connecte probablement vers l'ouest à l'ancienne suture, qui marque la limite des terrains océaniques accrétés au continent. L'analyse du réseau de drainage souligne de plus la propagation du système de failles de Quito vers le nord et vers l'Est, depuis le Quaternaire récent.Pour finir, à partir de ces nouveaux modèles locaux et régionaux de déformation Quaternaire pour l'Equateur, nous avons caractérisé et défini 19 nouvelles sources sismogéniques pour la croûte continentale. Cet apport permettra d'intégrer la tectonique active dans les futurs calculs d'aléa sismique pour aider à la définition du risque sur le territoire Equatorien.
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Hall, Eric K. "A study of slender beams: finite deformations, chaotic vibrations, and active control." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/12919.
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PANARA, YURI. "Fracture pattern and surface deformations induced by active buried faults: seismotectonic implications." Doctoral thesis, Università degli studi di Pavia, 2020. http://hdl.handle.net/11571/1317328.
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Fedosov, Boris. "Non-Abelian reduction in deformation quantization." Universität Potsdam, 1997. http://opus.kobv.de/ubp/volltexte/2008/2510/.
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We consider a G-invariant star-product algebra A on a symplectic manifold (M,ω) obtained by a canonical construction of deformation quantization. Under assumptions of the classical Marsden-Weinstein theorem we define a reduction of the algebra A with respect to the G-action. The reduced algebra turns out to be isomorphic to a canonical star-product algebra on the reduced phase space B. In other words, we show that the reduction commutes with the canonical G-invariant
deformation quantization. A similar statement in the framework of geometric quantization is known as the Guillemin-Sternberg conjecture (by now completely proved).