Dissertations / Theses on the topic 'Seismic instrumentation'

Concrete block masonry is a common building material used worldwide, including Canada. Reinforced masonry buildings, designed according to the requirements of recent building codes, may result in seismically safe structures. However, unreinforced masonry (URM) buildings designed and constructed prior to the development of modern seismic design codes are extremely vulnerable to seismic induced damage. Replacement of older seismically deficient buildings with new and seismically designed structures is economically not feasible in most cases. Therefore, seismic retrofitting of deficient buildings remains to be a viable seismic risk mitigation strategy. Masonry load bearing walls are the most important elements of such buildings, potentially serving as lateral force resisting systems. A seismic retrofit research program is currently underway at the University of Ottawa, consisting of experimental and analytical components for developing new seismic retrofit systems for unreinforced masonry walls. The research project presented in this thesis forms part of the same overall research program. The experimental component includes design, construction, retrofit and testing of large-scale load bearing masonry walls. Two approaches were developed as retrofit methodologies, both involving reinforcing the walls for strength and deformability. The first approach involves the use of ordinary deformed steel reinforcement as internally added reinforcement to attain reinforced masonry behaviour. The second approach involves the use of internally placed post-tensioning tendons to attain prestressed masonry behaviour. The analytical component of research consists of constructing a Finite Element computer model for nonlinear analysis of walls and conducting a parametric study to assess the significance of retrofit design parameters. The results have led to the development of a conceptual retrofit design framework for the new techniques developed, while utilizing the seismic provisions of the National Building Code of Canada and the relevant CSA material standards.

L’érosion des édifices volcaniques résulte d’une série de processus géomorphologiques qui se produisent pendant, avant ou sans éruption. Ce processus implique également le terme « lahar » qui décrit un écoulement rapide de la zone sommitale vers l’aval amenant des matériaux volcaniques mélangés à de l’eau avec une évolution de la dynamique d’écoulement dans l’espace et dans le temps. L’érosion des édifices volcaniques est encore mal connue, particulièrement en raison de la difficulté d’acquisition de données sur le terrain. Pourtant, les lahars ont causé à eux seuls au moins 44 250 morts de 1600 à 2010 dont 52 % à cause d’un seul évènement en 1985 (Nevado del Ruiz, Colombie). Cette étude propose une approche multiscalaire pour mieux comprendre la nature de l’érosion des édifices volcaniques sur le déclenchement et la dynamique des lahars. L’éruption du volcan Merapi (Indonésie) en2010 fut l’occasion de produire de nouvelles données de terrain. La première partie de la thèse, relative au déclenchement des lahars, repose sur des données de terrain et des expérimentations en laboratoire. Le travail de terrain avait pour but de comparer un bassin versant bouleversé par l’éruption de 2010 et un autre bassin versant non bouleversé, par le biais d’observations in-situ et d’instrumentation de terrain. En laboratoire, l’approche expérimentale fut réalisée en utilisant 8 scénarios différents sur un plan incliné. La deuxième partie, liée à la dynamique des lahars en mouvement, fut étudiée à partir du couplage vidéo signaux sismiques. Les dépôts liés à ces lahars furent également analysés et mis en regard de la chronologie des écoulements. Trois ans après l’éruption du Merapi en 2010, les lahars se sont raréfiés. Cependant, les dépôts de cendres juvéniles issues d’une autre éruption d’un volcan voisin (Kelud à Java Est) eurent comme résultat une augmentation significative du nombre de lahars à partir de février 2014. Le déclenchement des lahars fut également favorisé par des glissements de terrain connectés aux thalwegs, comme celui produit dans la nuit du 6 au 7 décembre 2012, que nous avons étudié en détail. La dynamique des deux lahars observés et filmés les 28 février et 18 mars 2014 fut divisée en 4 phases : (1) écoulement hyperconcentré, (2) pic de coulée de débris, (3) corps du lahar, (4) queue du lahar. L’analyse vidéo et l’observation in-situ sur les lahars en mouvement a permis de créer des hydrogrammes détaillés indiquant la profondeur, la vitesse, le débit et le nombre des blocs métriques flottés. La dynamique des lahars sur les différentes topographies du chenal a provoqué une fréquence sismique très différente. La formation des dépôts de lahars fut corrélée à la dynamique des écoulements et nécessita une observation in-situ pour la validation d’interprétation<br>The erosion of volcanic edifices is a series of geomorphological processes that occurs during, before or without eruption. This process also involves the term "lahar" which is characterized by dense mixtures of volcanic materials and water, rapidly flowing from a volcano with important spatio-temporal rheological changes. The erosion of volcanic edifices is still poorly understood, particularly because data collection in the field is difficult. However, lahars have caused at least 44,250 deaths from 1600 to 2010 of which 52%due to a single event in 1985 (Nevado del Ruiz, Colombia).This study proposes a multi-scalar approach to better understand the nature of the erosion of volcanic edifices, especially on lahar initiation process and dynamics. The eruption of the Merapi volcano(Indonesia) in 2010 was an opportunity to produce new data. The first part of this thesis focused on the lahar initiation process, was based on field data and laboratory experiments. The field work was intended to compare a volcanically disturbed watershed by the eruption of 2010 and an undisturbed watershed, by conducting in-situ observations and field instrumentation. In the laboratory, an experimental approach was performed using 8 different scenarios on a flume. The second part of the thesis related to the dynamics of two lahars in motion was conducted using coupling between video footage and seismic signal. Lahar deposits were also analyzed based on the chronology of the flows. Three years after the eruption of Merapi in 2010, the frequency of lahar occurrence decreased. However, juvenile ash fall deposits (volcanic ash) from another eruption of a nearby volcano (Kelud in East Java) in February 2014 resulted a significant increase of lahars occurrence. Lahars triggering process was also favored by a landslides occurring in the night of 6 to 7 December 2012, of which the deposit was connected to the thalweg. The dynamics of the two lahars were observed and filmed on 28 February and18 March 2014. Those lahars were divided into four phases: (1) hyperconcentrated flow, (2) the peak of debris flow, (3) lahar body, and (4) lahar tail. Video analysis and in-situ observation on active lahars allowed us to create detailed hydrographs indicating flow depth, velocity, discharge and the number of floated boulders. Lahar dynamics on different topography of the channel caused a very different seismic frequency. The formation of lahar deposits was correlated with the flow dynamics and required an in-situ observation for the validation of the interpretation<br>Erosi kerucut vulkanik merupakan hasil dari serangkaian proses geomorfologi yang terjadi baik selama,sebelum atau tanpa erupsi. Proses ini juga melibatkan "lahar" yang didefinisikan sebagai aliran cepat daridaerah puncak gunung menuju hilir dengan membawa material vulkanik yang bercampur dengan airdimana dinamika alirannya terus berubah secara spasial dan temporal. Erosi struktur vulkanik masihsedikit ditelaah, terutama karena sulitnya pengumpulan data di lapangan. Padahal, lahar telahmenyebabkan setidaknya 44.250 kematian dari tahun 1600 sampai 2010, dimana 52% -nya terkait denganbencana pada tahun 1985 di gunung Nevado del Ruiz (Kolombia).Penelitian ini mengusulkan pendekatan multi-skalar untuk lebih memahami karakteristik erosi kerucutvulkanik terutama yang terkait dengan pemicu dan dinamika aliran lahar. Letusan Gunung Merapi(Indonesia) pada tahun 2010 memberikan kesempatan untuk menghasilkan data lapangan baru. Bagianpertama dari disertasi ini, mengenai pemicu lahar, dilakukan berdasarkan data lapangan dan experimenlaboratorium. Kegiatan lapangan dimaksudkan untuk membandingkan DAS yang terdampak oleh letusan2010 dan DAS alami, melalui pengamatan in-situ dan instrumentasi lapangan. Di laboratorium,pendekatan eksperimental dilakukan dengan menggunakan 8 skenario yang berbeda pada flume. Bagiankedua dari disertasi ini berkaitan dengan dinamika aliran lahar aktif yang dipelajari dari perpaduanrekaman video dan sinyal seismik. Proses sedimentasi juga dianalisis dengan dipertimbangkan kronologialiran lahar.Tiga tahun setelah letusan Merapi pada tahun 2010, frekuensi kejadian lahar berkurang. Namun,sedimentasi abu vulkanik yang berasal dari gunung api lain (Kelud di Jawa Timur) telah mengakibatkanpeningkatan jumlah lahar yang signifikan sejak Februari 2014. Pembentukan lahar juga dipicu oleh tanahlongsor yang terjadi pada pada malam 6 menuju 7 Desember 2012 dimana materialnya terhubunglangsung ke thalweg. Dinamika dua aliran lahar diamati dan difilmkan pada tanggal 28 Februari dan 18Maret 2014. Lahar tersebut dibagi menjadi empat fase: (1) aliran hyperconcentrated, (2) puncak alirandebris, (3) tubuh lahar, (4) ekor lahar. Analisis video dan pengamatan in-situ pada lahar aktif sangatmembantu pembuatan hidrograf secara rinci terkait dengan kedalaman aliran, kecepatan, debit dan jumlahbatu yang terapung. Dinamika lahar pada topografi sungai yang berbeda menimbulkan frekuensi seismikyang sangat berbeda. Proses sedimentasi lahar sangat berkaitan dengan dinamika aliran lahar dandiperlukan pengamatan in-situ untuk memvalidasi interpretasi yang dibuat<br>La erosión de los edificios volcánicos es el resultado de una serie de procesos geomorfológicos que ocurre durante, antes o sin erupción. Este proceso también involucra el término "lahar", un flujo rápido de la cumbre de volcán hacia el rio que contiene una mezcla de materiales volcánicos y agua con cambio espacial y temporal. La erosión de los edificios volcánicos aún es poco estudiado debido a las dificultades para la obtención de los datos en el campo y además es peligroso. Mientras, los lahares han causado 44 250 muertos desde 1600 a 2010, en el cual de 52% ha sido causado por un evento único en 1985 (Nevado del Ruiz, Colombia). Esta investigación propone un acercamiento multiescalar para entender mejor las características de erosión de los edificios volcánicos, en particular el proceso de descenso y la dinámica de lahares. La erupción del volcán Merapi (Indonesia) en 2010 fue una oportunidad para generar nuevos datos. La primera parte de esta tesis enfocada al proceso de iniciación de descenso de lahares, que fue basada en la obtención de los datos de campo y experimentos en el laboratorio. El trabajo de campo fue realizado con el objetivo de comparar una cuenca hidrográfica afectada por la erupción de 2010 y una otra cuenca natural, a través de la observación in-situ y la instrumentación geofísica en el campo. En el laboratorio, el trabajo fue realizado con 8 escenarios diferentes usando un canal artificial. La segunda parte de esta tesis fue relacionada a la dinámica de movimiento de lahares que se realizó a través del acoplamiento de vídeos y señales sísmicas. Se analizó también el proceso de sedimentación basado en la cronología de los flujos de lahares. Tres años después de la erupción del Merapi en 2010, la frecuencia de ocurrencia de lahares se disminuye. Sin embargo, la sedimentación de ceniza volcánica de otra erupción de un volcán cercano (Kelud en Java Oriental) causó un aumento significativo de la ocurrencia de lahares desde febrero de 2014. La formación de lahares también se provocó por deslizamiento de tierra que se ocurrió en la noche de 6 a 7 de diciembre de 2012, en la que los materiales se juntaron directamente a la vaguada. La dinámica de dos flujos de lahares fue observada y grabada en video el 28 de febrero y 18 de marzo 2014. Estos dos lahares se dividieron en cuatro fases: (1) flujo hiperconcentrado, (2) el pico de flujo de escombros, (3) cuerpo de lahar, (4) cola de lahar. El análisis de video y la observación in-situ de lahares activos nos han ayudado a crear los hidrogramas en detalle que muestran la profundidad del flujo, la velocidad, la descarga y el número de rocas flotadas. La dinámica de lahares en diferentes topografías del canal causó una frecuencia sísmica muy diferente. El proceso de sedimentación de lahares se correlacionó con la dinámica de flujo y se requiere una observación in-situ para validar la interpretación

Les conditions de fonctionnement des sismographes fond de mer imposent le conditionnement des signaux pour limiter les debits d'information lors de l'enregistrement ou de la transmission. Trois methodes deduites de la transformation de fourier, de la transformation de walsh et de la modelisation autoregression sont examines et testes

La sismique monotrace informatisée est une technique qui s'inscrit, dans le domaine des méthodes de prospection géophysique, entre le sondage sismique continu et la sismique pétrolière multitrace. Elle utilise le matériel du sondage sismique continu pour l'acquisition en mer des profils, et le traitement des données se fait simultanément sur micro-ordinateur installé sur le navire. Les nouvelles conditions d'exploration et d'exploitation du plateau continental exigent une précision dans la résolution que la sismique multitrace classique, procédé lourd et couteux, ne peut entièrement satisfaire, mais ou une instrumentation légère et flexible semblable à celle exposée ici trouverait sa place.

Etude du champ magnetique terrestre sur les edifices volcaniques ou dans les regions soumises a une activite sismotectonique. Trois themes de recherche sont developpes: l'acquisition des mesures de terrain, les mesures experimentales realisees en laboratoire, et les simulations numeriques. L'etude de terrain porte sur des resultats obtenus sur les volcans de la soufriere de guadeloupe, la montagne pelee de martinique et le piton de la fournaise a la reunion

<p>This study explores the problems of identifying structural damage in steel frame buildings, through the use of dense instrumentation over the height of the building, and of characterizing the ground motion response in urban Los Angeles following the 2019 Ridgecrest earthquakes, through the use of dense instrumentation from available seismic networks, including the very dense Community Seismic Network.</p> <p>First we explore the possibility of tracing possible nonlinear behavior of a structure by updating an equivalent linear system model in short time segments of the earthquake-induced excitation and response time histories, using a moving time window approach. The stiffness and damping related parameters of the equivalent linear model are estimated by minimizing a measure of fit between the measured and model predicted response time histories for each time window. We explore the effectiveness of the methodology for two example applications, a single-story and a six-story steel moment frame building. For the single-story building, the methodology is shown to be very effective in tracing the nonlinearities, while the six-story building is designed to also reveal the limitations of the methodology, mainly arising from the different types of model errors manifested in the formulation.</p> <p>Next, we investigate the problem of structural damage identification through the use of sparse Bayesian learning (SBL) techniques. This is based on the premise that damage in a structure appears only in a limited number of locations. SBL methods that had been previously applied for structural damage identification used measurements related to modal properties and were thus limited to linear models. Here we present a methodology that allows for the application of SBL in non-linear models, using time history measurements recorded from a dense network of sensors installed along the building height. We develop a two-step optimization algorithm in which the most probable values of the structural model parameters and the hyper-parameters are iteratively obtained. An equivalent single-objective minimization problem that results in the most probable model parameter values is also derived. We consider the example problem of identifying damage in the form of weld fractures in a 15-story moment resisting steel frame building, using a nonlinear finite element model and simulated acceleration data. Fiber elements and a bilinear material model are used in order to account for the change of local stiffness when cracks at the welds are subjected to tension and the model parameters characterize the loss of stiffness as the crack opens under tension. The damage identification results demonstrate the effectiveness and robustness of the proposed methodology in identifying the existence, location, and severity of damage for a variety of different damage scenarios, and degrees of model and measurement errors. The results show the great promise of the SBL methodology for damage identification by integrating nonlinear finite element models and response time history measurements.</p> <p>The final part of the thesis involves studying the ground motion response in urban Los Angeles during the two largest events (M7.1 and M6.4) of the 2019 Ridgecrest earthquake sequence using recordings from multiple regional seismic networks as well as a subset of 350 stations from the much denser Community Seismic Network. The response spectral (pseudo) accelerations for a selection of periods of engineering significance are calculated. Significant spectral acceleration amplification is present and reproducible between the two events. For the longer periods, coherent spectral acceleration patterns are visible throughout the Los Angeles Basin, while for the shorter periods, the motions are less spatially coherent. The dense Community Seismic Network instrumentation allows us to observe smaller-scale coherence even for these shorter periods. Examining possible correlations of the computed response spectral accelerations with basement depth and Vs30, we find the correlations to be stronger for the longer periods. Furthermore, we study the performance of two state-of-the-art methods for estimating ground motions for the largest event of the Ridgecrest earthquake sequence, namely 3D finite difference simulations and ground motion prediction equations. For the simulations, we are interested in the performance of the two Southern California Earthquake Center 3D Community Velocity Models (CVM-S and CVM-H). For the ground motion prediction equations, we consider four of the 2014 Next Generation Attenuation-West2 Project equations. For some cases, the methods match the observations reasonably well; however, neither approach is able to reproduce the specific locations of the maximum response spectral accelerations, or match the details of the observed amplification patterns.</p>

Sensors have been an integral part of human life. Various sensor technologies have contributed in their own ways to fulfill specific requirements for aiding human beings. In this context, fiber optic sensors have several advantages such as availability of large number of components from communication industry, small footprint, easy fabrication, and immunity to Electro Magnetic Interference. In the category of fiber optic sensors, Fiber Bragg Gratings (FBGs) have been found to be very useful, because of their high sensitivity, multi-modal sensing ability, large operational bandwidth, and multiplexing capability. An FBG is a periodic orthogonal perturbation of the refractive index along the longitudinal axis of the core of a single mode optical fiber. The periodic modulation of index of refraction is brought about by exploiting the photosensitivity of a germania- doped silica fiber upon exposure to UV light. FBGs, in the basic form, can sense strain and temperature. However, in recent years, several newer sensing applications of FBGs are being explored and the present thesis is an attempt in this direction. In this thesis work, Fiber Bragg Grating sensor-based devices have been devised for newer applications in bio-medical and engineering fields. Basically, novel packaging methodologies for FBGs are designed and developed, which transduce the measured parameter to a secondary parameter that can be sensed by the FBG. In the field of Cardiology, an FBG Pulse Recorder has been developed which has the ability to acquire the radial arterial pulse pressure waveform. It records the beat-to-beat pulse pressure along with the radial arterial diametrical variations. The FBG Pulse Recorder has been employed to measure the blood pressure in conjunction with a sphygmomanometer, using the unique signatures obtained in the radial arterial pulse pressure waveform. By the same methodology, radial arterial compliance, is evaluated. Also, using two FBG Pulse Recorders at the carotid and radial arterial sites the pulse transit time differential is measured which acts as an indicator of variation in systolic blood pressure and pulse wave velocity. In the field of dentistry, a novel technique for real time dynamic measurement of the maximum individual bite force using Fiber Bragg Grating Bite Force Recorder has been proposed. The results obtained show that bite forces increase along the dental arch and are found to be higher in male than in female. Also, an in-vitro study utilizing the FBG temperature sensor has been carried out to measure the variation of temperature in the pulp chamber during light curing of composite materials. In the field of seismology, a new methodology for real time dynamic monitoring of seismic vibrations, using a Fiber Bragg Grating Seismic Sensor has been proposed. The validation and field tests are carried out in comparison with a commercial seismometer. Further, the feasibility study for an elephant intrusion monitoring system employing the sensor developed has been put forth. Furthermore, a displacement device has been devised which converts displacement into strain on a cantilever beam over which the FBG sensor is bonded with the aid of a pivoted arm. This arm provides the necessary mechanical amplification of the displacement by varying the pivot screw position, facilitating tunable sensitivity for the FBG displacement device. Also, the same device has been used for measurement of vibration and with enhanced sensitivity for surface profilometry with a resolution of 175nm. To summarize, the present thesis demonstrates a comprehensive experimental study which bring out the utility of FBG sensors in variety of challenging applications.

Sensors have become essential elements in human life for safe and comfortable existence in the ever demanding world. Various technologies over decades have contributed in their own way fulfilling innumerable sensing requirements. The discovery of optical sensor technologies has revolutionized the sensing field due to their inherent advantages. Among the large number of fiber optic sensor technologies, FBG based sensors have become widely known and popular within and outside the photonics community and has seen a prominent rise in their utilization. This thesis explores the use of FBG sensors for a wide range of applications scanning across a variety of engineering and medical applications, in the areas of civil engineering, biomechanical engineering, aerospace engineering, geoengineering, etc. It also deals with newer methods of packaging FBG sensors for the measurement of specific engineering parameters like strain, temperature, pressure, displacement and vibration. In the field of civil engineering, FBG sensors are employed for strain sensing on a prism and furthermore tested on a full size brick wallet. During this study, emphasis is made on substituting traditional sensors by specially packaged FBG sensors with the intent of either enhancing the sensing system’s performance or in merging/uniting the inherent advantages of FBG sensors. In the area of biomechanics, a novel sensor methodology using FBG sensors, for measuring surface strains generated on the skin of the calf muscle during various leg exercises is proposed. This methodology is used to address one of the most critical and life threatening issues in long distance air travel, namely the Deep Vein Thrombosis. Further, a FBG sensor based plantar sensing plate, is designed and developed, to measure plantar strain distribution in foot and also to analyze the postural stability. In the field of aerospace engineering, FBG sensors are used for addressing two of the most vital issues; Structural Health Monitoring (SHM) and direct measurement of pressure and temperature on the surface of an aircraft under hypersonic wind flow. Carbon Fiber Composite coupon level testing is carried out to obtain a generic strain calibration factor for the FBG sensor. Further, FBG sensors are exploited for the direct measurement of absolute temperature and pressure on the leeward surface of blunt cone at hypersonic wind speeds. In the domain of geoengineering, the feasibility studies have been undertaken to use a FBG as a seismic sensor and as a bore-well characterizing sensor. A novel FBG seismic sensor package is developed using a single FBG sensor to pick up the seismic waves propagating through the ground generated from earthquakes and ground tremors. Further, FBG sensors are used for measurement of temperature profiles in a bore-well to delineate and characterize the behavior of fractures during seasonal climatic changes. To summarize, the present thesis demonstrates a comprehensive experimental study which bring out the utility of FBG sensors in a variety of challenging applications.

Sensors have become essential elements in human life for safe and comfortable existence in the ever demanding world. Various technologies over decades have contributed in their own way fulfilling innumerable sensing requirements. The discovery of optical sensor technologies has revolutionized the sensing field due to their inherent advantages. Among the large number of fiber optic sensor technologies, FBG based sensors have become widely known and popular within and outside the photonics community and has seen a prominent rise in their utilization. This thesis explores the use of FBG sensors for a wide range of applications scanning across a variety of engineering and medical applications, in the areas of civil engineering, biomechanical engineering, aerospace engineering, geoengineering, etc. It also deals with newer methods of packaging FBG sensors for the measurement of specific engineering parameters like strain, temperature, pressure, displacement and vibration. In the field of civil engineering, FBG sensors are employed for strain sensing on a prism and furthermore tested on a full size brick wallet. During this study, emphasis is made on substituting traditional sensors by specially packaged FBG sensors with the intent of either enhancing the sensing system’s performance or in merging/uniting the inherent advantages of FBG sensors. In the area of biomechanics, a novel sensor methodology using FBG sensors, for measuring surface strains generated on the skin of the calf muscle during various leg exercises is proposed. This methodology is used to address one of the most critical and life threatening issues in long distance air travel, namely the Deep Vein Thrombosis. Further, a FBG sensor based plantar sensing plate, is designed and developed, to measure plantar strain distribution in foot and also to analyze the postural stability. In the field of aerospace engineering, FBG sensors are used for addressing two of the most vital issues; Structural Health Monitoring (SHM) and direct measurement of pressure and temperature on the surface of an aircraft under hypersonic wind flow. Carbon Fiber Composite coupon level testing is carried out to obtain a generic strain calibration factor for the FBG sensor. Further, FBG sensors are exploited for the direct measurement of absolute temperature and pressure on the leeward surface of blunt cone at hypersonic wind speeds. In the domain of geoengineering, the feasibility studies have been undertaken to use a FBG as a seismic sensor and as a bore-well characterizing sensor. A novel FBG seismic sensor package is developed using a single FBG sensor to pick up the seismic waves propagating through the ground generated from earthquakes and ground tremors. Further, FBG sensors are used for measurement of temperature profiles in a bore-well to delineate and characterize the behavior of fractures during seasonal climatic changes. To summarize, the present thesis demonstrates a comprehensive experimental study which bring out the utility of FBG sensors in a variety of challenging applications.

Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time. A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.