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Journal articles on the topic 'Computational geochemistry'

Author: Grafiati

Published: 6 September 2023

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1

Buccianti, Antonella. "Advanced computational geochemistry." Computers & Geosciences 37, no. 5 (2011): 645. http://dx.doi.org/10.1016/j.cageo.2011.03.012.

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Gao, Wenlei, Gian Matharu, and Mauricio D. Sacchi. "Fast least-squares reverse time migration via a superposition of Kronecker products." GEOPHYSICS 85, no. 2 (2020): S115—S134. http://dx.doi.org/10.1190/geo2019-0254.1.

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Least-squares reverse time migration (LSRTM) has become increasingly popular for complex wavefield imaging due to its ability to equalize image amplitudes, attenuate migration artifacts, handle incomplete and noisy data, and improve spatial resolution. The major drawback of LSRTM is the considerable computational cost incurred by performing migration/demigration at each iteration of the optimization. To ameliorate the computational cost, we introduced a fast method to solve the LSRTM problem in the image domain. Our method is based on a new factorization that approximates the Hessian using a s

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Liu, Faqi, Guanquan Zhang, Scott A. Morton, and Jacques P. Leveille. "An optimized wave equation for seismic modeling and reverse time migration." GEOPHYSICS 74, no. 6 (2009): WCA153—WCA158. http://dx.doi.org/10.1190/1.3223678.

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The acoustic wave equation has been widely used for the modeling and reverse time migration of seismic data. Numerical implementation of this equation via finite-difference techniques has established itself as a valuable approach and has long been a favored choice in the industry. To ensure quality results, accurate approximations are required for spatial and time derivatives. Traditionally, they are achieved numerically by using either relatively very fine computation grids or very long finite-difference operators. Otherwise, the numerical error, known as numerical dispersion, is present in t

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Rustad, J. R., W. Dzwinel, and D. A. Yuen. "Computational Approaches to Nanomineralogy." Reviews in Mineralogy and Geochemistry 44, no. 1 (2001): 191–216. http://dx.doi.org/10.2138/rmg.2001.44.06.

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5

Yong, Peng, Romain Brossier, and Ludovic Métivier. "Parsimonious truncated Newton method for time-domain full-waveform inversion based on the Fourier-domain full-scattered-field approximation." GEOPHYSICS 87, no. 1 (2021): R123—R146. http://dx.doi.org/10.1190/geo2021-0164.1.

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To exploit Hessian information in full-waveform inversion (FWI), the matrix-free truncated Newton method can be used. In such a method, Hessian-vector product computation is one of the major concerns due to the huge memory requirements and demanding computational cost. Using the adjoint-state method, the Hessian-vector product can be estimated by zero-lag crosscorrelation of the first-/second-order incident wavefields and the second-/first-order adjoint wavefields. Different from the implementation in frequency-domain FWI, Hessian-vector product construction in the time domain becomes much mor

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Ignetik, Rainer. "Response by R. Ignetik to the author's reply." GEOPHYSICS 54, no. 11 (1989): 1502. http://dx.doi.org/10.1190/1.1486970.

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It would be interesting to compare the two computational algorithms proposed by Raiche with Boerner and West's approach, to see which of the three is computationally fastest under similar conditions. I also note that although the semi-analytic algorithm proposed by Raiche is more elegant and may require less storage, the paper does not make it entirely clear whether we get a real reduction in computing time; reduced computational time was the motivation for the procedure in the first place.

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Bensdorp, Silvian, Steen A. Petersen, Peter M. van den Berg, and Jacob T. Fokkema. "An approximate 3D computational method for real-time computation of induction logging responses." GEOPHYSICS 79, no. 3 (2014): E137—E148. http://dx.doi.org/10.1190/geo2013-0233.1.

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Over many years, induction logging systems have been used to create well formation logs. The major drawback for the utilization of these tools is the long simulation time for a single forward computation. We proposed an efficient computational method based on a contrast-type of integral-equation formulation, in which we applied an approximation for the 3D electromagnetic field. We assumed that the dominant contribution in the integral equation is obtained by the contribution around the singularity of Green’s kernel. It is expected that the approximation yields reliable results when the (homoge

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Carcione, José M., Christina Morency, and Juan E. Santos. "Computational poroelasticity — A review." GEOPHYSICS 75, no. 5 (2010): 75A229–75A243. http://dx.doi.org/10.1190/1.3474602.

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Computational physics has become an essential research and interpretation tool in many fields. Particularly in reservoir geophysics, ultrasonic and seismic modeling in porous media is used to study the properties of rocks and to characterize the seismic response of geologic formations. We provide a review of the most common numerical methods used to solve the partial differential equations describing wave propagation in fluid-saturated rocks, i.e., finite-difference, pseudospectral, and finite-element methods, including the spectral-element technique. The modeling is based on Biot-type theorie

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9

Goes, Saskia. "Computational methods for geodynamics." Geophysical Journal International 184, no. 2 (2010): 974. http://dx.doi.org/10.1111/j.1365-246x.2010.04898.x.

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10

Zhang, Yang, and M. Nafi Toksöz. "Impact of the cracks lost in the imaging process on computing linear elastic properties from 3D microtomographic images of Berea sandstone." GEOPHYSICS 77, no. 2 (2012): R95—R104. http://dx.doi.org/10.1190/geo2011-0126.1.

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With the current developments in imaging/computational techniques and resources, computational rock physics has been emerging as a new field of study. Properties of rocks are examined by carrying out extensive numerical simulations on rocks that have been digitized using high-resolution X-ray CT scans. The ultimate goal of computational rock physics is to supplement the traditional laboratory measurements, which are time consuming, with faster numerical simulations that allow the parameter space to be explored more thoroughly. We applied the finite-element method to compute the static effectiv

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Momma, Koichi, Toshiro Nagase, Yasuhiro Kudoh, and Takahiro Kuribayashi. "Computational simulations of the structure of Japan twin boundaries in quartz." European Journal of Mineralogy 21, no. 2 (2009): 373–83. http://dx.doi.org/10.1127/0935-1221/2009/0021-1893.

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12

Löer, Katrin, Andrew Curtis, and Giovanni Angelo Meles. "Relating source-receiver interferometry to an inverse-scattering series to derive a new method to estimate internal multiples." GEOPHYSICS 81, no. 3 (2016): Q27—Q40. http://dx.doi.org/10.1190/geo2015-0330.1.

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We have evaluated an explicit relationship between the representations of internal multiples by source-receiver interferometry and an inverse-scattering series. This provides a new insight into the interaction of different terms in each of these internal multiple prediction equations and explains why amplitudes of estimated multiples are typically incorrect. A downside of the existing representations is that their computational cost is extremely high, which can be a precluding factor especially in 3D applications. Using our insight from source-receiver interferometry, we have developed an alte

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Boonyasiriwat, Chaiwoot, Paul Valasek, Partha Routh, Weiping Cao, Gerard T. Schuster, and Brian Macy. "An efficient multiscale method for time-domain waveform tomography." GEOPHYSICS 74, no. 6 (2009): WCC59—WCC68. http://dx.doi.org/10.1190/1.3151869.

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This efficient multiscale method for time-domain waveform tomography incorporates filters that are more efficient than Hamming-window filters. A strategy for choosing optimal frequency bands is proposed to achieve computational efficiency in the time domain. A staggered-grid, explicit finite-difference method with fourth-order accuracy in space and second-order accuracy in time is used for forward modeling and the adjoint calculation. The adjoint method is utilized in inverting for an efficient computation of the gradient directions. In the multiscale approach, multifrequency data and multiple

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Chen, Jing-Bo. "High-order time discretizations in seismic modeling." GEOPHYSICS 72, no. 5 (2007): SM115—SM122. http://dx.doi.org/10.1190/1.2750424.

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Seismic modeling plays an important role in explor-ation geophysics. High-order modeling schemes are in demand for practical reasons. In this context, I present three kinds of high-order time discretizations: Lax-Wendroff methods, Nyström methods, and splitting methods. Lax-Wendroff methods are based on the Taylor expansion and the replacement of high-order temporal derivatives by spatial derivatives, Nyström methods are simplified Runge-Kutta algorithms, and splitting methods comprise substeps for one-step computation. Based on these methods, three schemes with third-order and fourth-order ac

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Wei, Wei, Li-yun Fu, and Gerrit Blacquière. "Fast multifrequency focal beam analysis for 3D seismic acquisition geometry." GEOPHYSICS 77, no. 2 (2012): P11—P21. http://dx.doi.org/10.1190/geo2010-0327.1.

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A method for the efficient computation of multifrequency focal beams for 3D seismic acquisition geometry analysis has been developed. By computing them for all the frequency components of seismic data, single-frequency focal beams can be extended to multifrequency focal beams. However, this straightforward method involves considerable computer time and memory requirements, especially in complex media settings. Therefore, we propose a rapid 3D multifrequency focal beam method in which only a few single-frequency focal beam computations are followed by a number of smart interpolations. The 3D wa

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van Duin, Adri C. T., and Jaap S. Sinninghe Damsté. "Computational chemical investigation into isorenieratene cyclisation." Organic Geochemistry 34, no. 4 (2003): 515–26. http://dx.doi.org/10.1016/s0146-6380(02)00247-4.

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Dvorkin, Jack, Naum Derzhi, Elizabeth Diaz, and Qian Fang. "Relevance of computational rock physics." GEOPHYSICS 76, no. 5 (2011): E141—E153. http://dx.doi.org/10.1190/geo2010-0352.1.

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To validate the transport (fluid and electrical) and elastic properties computed on CT scan pore-scale volumes of natural rock, we first contrast these values to physical laboratory measurements. We find that computational and physical data obtained on the same rock material source often differ from each other. This mismatch, however, does not preclude the validity of either of the data type — it only implies that expecting a direct match between the effective properties of two volumes of very different sizes taken from the same heterogeneous material is generally incorrect. To address this si

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18

Donnellan, Andrea, Peter Mora, Mitsuhiro Matsu’ura, and Xiang-Chu Yin. "Computational Earthquake Science Part I." Pure and Applied Geophysics 161, no. 9-10 (2004): 1823–25. http://dx.doi.org/10.1007/s00024-004-2533-2.

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Donnellan, Andrea, Peter Mora, Mitsuhiro Matsu’ura, and Xiang-chu Yin. "Computational Earthquake Science PART II." Pure and Applied Geophysics 161, no. 11-12 (2004): 2119–22. http://dx.doi.org/10.1007/s00024-004-2552-z.

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Hu, Jiangtao, Junxing Cao, Huazhong Wang, Shaoyong Liu, and Xingjian Wang. "3D traveltime computation for quasi-P-wave in orthorhombic media using dynamic programming." GEOPHYSICS 83, no. 1 (2018): C27—C35. http://dx.doi.org/10.1190/geo2016-0558.1.

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A fractured area, such as a fault area, usually induces orthorhombic anisotropy. Ignoring orthorhombic anisotropy may degrade the subsurface image by creating a well mistie and blurring the image. Traveltime computation is essential for many processing techniques, such as depth imaging and tomography. Solving the ray-tracing system and eikonal equation are two popular methods for traveltime computation in isotropic media. However, because the ray-tracing system becomes complex and the eikonal equation becomes highly nonlinear, their applications in orthorhombic media become complex. We have de

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21

Gao, Kai, and Lianjie Huang. "An efficient vector elastic reverse time migration method in the hybrid time and frequency domain for anisotropic media." GEOPHYSICS 84, no. 6 (2019): S511—S522. http://dx.doi.org/10.1190/geo2018-0644.1.

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Vector elastic reverse time migration (ERTM) produces subsurface elastic images with correct polarities using multicomponent seismic data. However, the decomposition of elastic wavefields into vector P- and S-wavefields is computationally expensive, particularly in heterogeneous and complex anisotropic media. We have developed a computationally efficient vector ERTM method in the hybrid time and frequency domain by combining three existing techniques. Rather than decomposing elastic wavefields into vector qP- and qS-wavefields during time-domain wavefield propagation, we conduct the wavefield

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22

Zhang, Wensheng, and Hui Zheng. "A multiscale method for wave propagation in 3D heterogeneous poroelastic media." GEOPHYSICS 84, no. 4 (2019): T237—T257. http://dx.doi.org/10.1190/geo2018-0482.1.

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A new multiscale method for wave simulation in 3D heterogeneous poroelastic media is developed. Wave propagation in inhomogeneous media involves many different scales of media. The physical parameters in the real media usually vary greatly within a very small scale. For the direct numerical methods for wave simulation, a refined grid is required in mesh generation to maintain the match between the mesh size and the material variations in the spatial scale. This greatly increases the computational cost and computer memory requirements. The multiscale method can overcome this difficulty due to t

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23

Song, Guojie, Xinmin Zhang, Zhiliang Wang, Yali Chen, and Puchun Chen. "The asymptotic local finite-difference method of the fractional wave equation and its viscous seismic wavefield simulation." GEOPHYSICS 85, no. 3 (2020): T179—T189. http://dx.doi.org/10.1190/geo2019-0066.1.

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Viscous seismic wave propagation simulation using the fractional order equation has attracted much recent attention. However, conventional finite-difference (FD) methods of the fractional partial difference equation adopt a global difference operator to approximate the fractional derivatives, which reduces the computational efficiency dramatically. To improve the efficiency of the FD method, we have developed a reasonable truncated stencil pattern by strict mathematical derivation and adopted an asymptotic local FD (ALFD) method. Theoretical analysis and numerical results indicate that the ALF

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24

Xiong, Zonghou. "Symmetry properties of the scattering matrix in 3-D electromagnetic modeling using the integral equation method." GEOPHYSICS 57, no. 9 (1992): 1199–202. http://dx.doi.org/10.1190/1.1443334.

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Modeling large three‐dimensional (3-D) earth conductivity structures continues to pose challenges. Although the theories of electromagnetic modeling are well understood, the basic computational problems are practical, involving the quadratically growing requirements on computer storage and cubically growing computation time with the number of cells required to discretize the modeling body.

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25

Redfern, Simon A. T. "Advances in computer modelling of mineral properties." Mineralogical Magazine 59, no. 397 (1995): 585–87. http://dx.doi.org/10.1180/minmag.1995.059.397.01.

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The following six papers were presented at a meeting, held in September 1994, which reviewed some of the recent advances in the application of computational methods to mineralogy. Talks covered the developing and challenging field of ab initio quantum mechanical computations as well as new applications and insights afforded by the use and refinement of the more established methods of empirical simulation and modelling. The former attempt to solve Schrdinger's equation for the material in question, and in doing so determine the energy surface and electronic structure. The latter use parameteriz

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Ferriss, Elizabeth D. A. Essene, and Udo Becker. "Computational study of the effect of pressure on the Ti-in-zircon geothermometer." European Journal of Mineralogy 20, no. 5 (2008): 745–55. http://dx.doi.org/10.1127/0935-1221/2008/0020-1860.

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Boehm, Christian, Mauricio Hanzich, Josep de la Puente, and Andreas Fichtner. "Wavefield compression for adjoint methods in full-waveform inversion." GEOPHYSICS 81, no. 6 (2016): R385—R397. http://dx.doi.org/10.1190/geo2015-0653.1.

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Adjoint methods are a key ingredient of gradient-based full-waveform inversion schemes. While being conceptually elegant, they face the challenge of massive memory requirements caused by the opposite time directions of forward and adjoint simulations and the necessity to access both wavefields simultaneously for the computation of the sensitivity kernel. To overcome this bottleneck, we have developed lossy compression techniques that significantly reduce the memory requirements with only a small computational overhead. Our approach is tailored to adjoint methods and uses the fact that the comp

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Ehlers, T. A. "Computational Tools for Low-Temperature Thermochronometer Interpretation." Reviews in Mineralogy and Geochemistry 58, no. 1 (2005): 589–622. http://dx.doi.org/10.2138/rmg.2005.58.22.

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29

Michelena, R. J., and J. M. Harris. "Tomographic traveltime inversion using natural pixels." GEOPHYSICS 56, no. 5 (1991): 635–44. http://dx.doi.org/10.1190/1.1443080.

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Traditionally in the problem of tomographic traveltime inversion, the model is divided into a number of rectangular cells of constant slowness. Inversion consists of finding these constant values using the measured traveltimes. The inversion process can demand a large computational effort if a high‐resolution result is desired. We show how to use a different kind of parameterization of the model based on beam propagation paths. This parameterization is obtained within the framework of reconstruction in Hilbert spaces by minimizing the error between the true model and the estimated model. The t

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Sun, H., and G. T. Schuster. "2‐D wavepath migration." GEOPHYSICS 66, no. 5 (2001): 1528–37. http://dx.doi.org/10.1190/1.1487099.

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Prestack Kirchhoff migration (KM) is computationally intensive for iterative velocity analysis. This is partly because each time sample in a trace must be smeared along a quasi‐ellipsoid in the model. As a less costly alternative, we use the stationary phase approximation to the KM integral so that the time sample is smeared along a small Fresnel zone portion of the quasi‐ellipsoid. This is equivalent to smearing the time samples in a trace over a 1.5‐D fat ray (i.e., wavepath), so we call this “wavepath migration” (WM). This compares to standard KM, which smears the energy in a trace along a

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Egbert, Gary D., and Anna Kelbert. "Computational recipes for electromagnetic inverse problems." Geophysical Journal International 189, no. 1 (2012): 251–67. http://dx.doi.org/10.1111/j.1365-246x.2011.05347.x.

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32

Yin, Xiang-chu, Peter Mora, Andrea Donnellan, and Mitsuhiro Matsuura. "Computational Earthquake Physics PART I: Introduction." Pure and Applied Geophysics 163, no. 9 (2006): 1737–40. http://dx.doi.org/10.1007/s00024-006-0112-4.

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Yin, Xiang-chu, Peter Mora, Andrea Donnellan, and Mitsuhiro Matsu'ura. "Computational Earthquake Physics PART II: Introduction." Pure and Applied Geophysics 163, no. 11-12 (2006): 2259–61. http://dx.doi.org/10.1007/s00024-006-0138-7.

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34

Reshef, Moshe, and David Kessler. "Practical implementation of three‐dimensional poststack depth migration." GEOPHYSICS 54, no. 3 (1989): 309–18. http://dx.doi.org/10.1190/1.1442656.

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This work deals with the practical aspects of three‐dimensional (3-D) poststack depth migration. A method, based on depth extrapolation in the frequency domain, is used for the migration. This method is suitable for structures with arbitrary velocity variation, and the number of computations required can be directly related to the complexity of the given velocity function. We demonstrate the superior computational efficiency of this method for 3-D depth migration relative to the reverse‐time migration method. The computational algorithm used for the migration is designed for a multi‐processor

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35

Shragge, Jeffrey. "Solving the 3D acoustic wave equation on generalized structured meshes: A finite-difference time-domain approach." GEOPHYSICS 79, no. 6 (2014): T363—T378. http://dx.doi.org/10.1190/geo2014-0172.1.

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The key computational kernel of most advanced 3D seismic imaging and inversion algorithms used in exploration seismology involves calculating solutions of the 3D acoustic wave equation, most commonly with a finite-difference time-domain (FDTD) methodology. Although well suited for regularly sampled rectilinear computational domains, FDTD methods seemingly have limited applicability in scenarios involving irregular 3D domain boundary surfaces and mesh interiors best described by non-Cartesian geometry (e.g., surface topography). Using coordinate mapping relationships and differential geometry,

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36

Biondi, Biondo, and Gopal Palacharla. "3-D prestack migration of common‐azimuth data." GEOPHYSICS 61, no. 6 (1996): 1822–32. http://dx.doi.org/10.1190/1.1444098.

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In principle, downward continuation of 3-D prestack data should be carried out in the 5-D space of full 3-D prestack geometry (recording time, source surface location, and receiver surface location), even when the data sets to be migrated have fewer dimensions, as in the case of common‐azimuth data sets that are only four dimensional. This increase in dimensionality of the computational space causes a severe increase in the amount of computations required for migrating the data. Unless this computational efficiency issue is solved, 3-D prestack migration methods based on downward continuation

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37

Robertsson, Johan O. A., and Chris H. Chapman. "An efficient method for calculating finite‐difference seismograms after model alterations." GEOPHYSICS 65, no. 3 (2000): 907–18. http://dx.doi.org/10.1190/1.1444787.

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Seismic modeling, processing, and inversion often require the calculation of the seismic response resulting from a suite of closely related seismic models. Even though changes to the model may be restricted to a small subvolume, we need to perform simulations for the full model. We present a new finite‐difference method that circumvents the need to resimulate the complete model for local changes. By requiring only calculations in the subvolume and its neighborhood, our method makes possible significant reductions in computational cost and memory requirements. In general, each source/receiver l

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38

Brown, R. James. "Computational errors in closed‐form expressions with an electromagnetic example: The conducting‐sphere response." GEOPHYSICS 53, no. 8 (1988): 1122–25. http://dx.doi.org/10.1190/1.1442550.

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Errors are expected to result from the numerical evaluation of approximate mathematical expressions such as truncated series and finite‐element solutions, from exact expressions based on approximate theory (e.g., perfect gas law), or from analysis based on field data. Many theoretical problems in science—and geophysics is no exception—involve a wholly correct mathematical expression that is beset with computational difficulties arising solely from numerical calculations using the expression. For example, even with modern computers, computation from a slowly convergent series expression can dem

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Feng, Xiaolei, Zvi Steiner, and Simon A. T. Redfern. "Fluorine incorporation into calcite, aragonite and vaterite CaCO3: Computational chemistry insights and geochemistry implications." Geochimica et Cosmochimica Acta 308 (September 2021): 384–92. http://dx.doi.org/10.1016/j.gca.2021.05.029.

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Pafeng, Josiane, Subhashis Mallick, and Hema Sharma. "Prestack waveform inversion of three-dimensional seismic data — An example from the Rock Springs Uplift, Wyoming, USA." GEOPHYSICS 82, no. 1 (2017): B1—B12. http://dx.doi.org/10.1190/geo2016-0079.1.

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Applying seismic inversion to estimate subsurface elastic earth properties for reservoir characterization is a challenge in exploration seismology. In recent years, waveform-based seismic inversions have gained popularity, but due to high computational costs, their applications are limited, and amplitude-variation-with-offset/angle inversion is still the current state-of-the-art. We have developed a genetic-algorithm-based prestack seismic waveform inversion methodology. By parallelizing at multiple levels and assuming a locally 1D structure such that forward computation of wave equation synth

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Bleistein, Norman, Jack K. Cohen, and Frank G. Hagin. "Computational and asymptotic aspects of velocity inversion." GEOPHYSICS 50, no. 8 (1985): 1253–65. http://dx.doi.org/10.1190/1.1441996.

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We discuss computational and asymptotic aspects of the Born inversion method and show how asymptotic analysis is exploited to reduce the number of integrations in an f-k like solution formula for the velocity variation. The output of this alternative algorithm produces the reflectivity function of the surface. This is an array of singular functions—Dirac delta functions which peak on the reflecting surfaces—each scaled by the normal reflection strength at the surface. Thus, imaging of a reflector is achieved by construction of its singular function and estimation of the reflection strength is

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Alekseev, A. S., M. M. Lavrentiev, V. G. Romanov, and M. E. Romanov. "Theoretical and computational aspects of seismic tomography." Surveys in Geophysics 11, no. 4 (1990): 395–409. http://dx.doi.org/10.1007/bf01902967.

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Zhao, Yan, Ningbo Mao, and Zhiming Ren. "A stable and efficient approach of Q reverse time migration." GEOPHYSICS 83, no. 6 (2018): S557—S567. http://dx.doi.org/10.1190/geo2018-0022.1.

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Amplitude energy attenuation and phase distortion of seismic waves caused by formation viscoelasticity reduce the resolution of reverse time migration (RTM) images. Q-RTM often is used to compensate the attenuation effects and improve the resolution of seismic imaging. However, serious high-frequency noise and tremendous amplitude will be produced during the wavefield extrapolation of Q-RTM, resulting in its inability to be imaged. Many Q-RTM algorithms solve the problem of instability through low-pass filtering in the wavenumber domain, but the method is less efficient in computation and has

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Yang, Dikun, and Douglas W. Oldenburg. "Survey decomposition: A scalable framework for 3D controlled-source electromagnetic inversion." GEOPHYSICS 81, no. 2 (2016): E69—E87. http://dx.doi.org/10.1190/geo2015-0217.1.

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Numerical modeling and inversion of electromagnetic (EM) data is a computationally intensive task. To achieve efficiency, we have developed algorithms that were constructed from a smallest practical computational unit. This “atomic” building block, which yields the solution of Maxwell’s equations for a single time or frequency datum due to an infinitesimal current or magnetic dipole, is a self-contained EM problem that can be solved independently and inexpensively on a single core of CPU. Any EM data set can be composed from these units through assembling or superposition. This approach takes

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Amestoy, Patrick, Romain Brossier, Alfredo Buttari, et al. "Fast 3D frequency-domain full-waveform inversion with a parallel block low-rank multifrontal direct solver: Application to OBC data from the North Sea." GEOPHYSICS 81, no. 6 (2016): R363—R383. http://dx.doi.org/10.1190/geo2016-0052.1.

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Wide-azimuth long-offset ocean bottom cable (OBC)/ocean bottom node surveys provide a suitable framework to perform computationally efficient frequency-domain full-waveform inversion (FWI) with a few discrete frequencies. Frequency-domain seismic modeling is performed efficiently with moderate computational resources for a large number of sources with a sparse multifrontal direct solver (Gauss-elimination techniques for sparse matrices). Approximate solutions of the time-harmonic wave equation are computed using a block low-rank (BLR) approximation, leading to a significant reduction in the op

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Sen, Mrinal K., and Indrajit G. Roy. "Computation of differential seismograms and iteration adaptive regularization in prestack waveform inversion." GEOPHYSICS 68, no. 6 (2003): 2026–39. http://dx.doi.org/10.1190/1.1635056.

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Seismic waveform inversion is a highly challenging task. Nonlinearity, nonuniqueness, and robustness issues tend to make the problem computationally intractable. We have developed a simple regularized Gauss‐Newton–type algorithm for the inversion of seismic data that addresses several of these issues. The salient features of our algorithm include an efficient approach to sensitivity computation, a strategy for band‐limiting the Jacobian matrix, and a novel approach to computing regularization weight that is iteration adaptive. In this paper, we first review various forward modeling and differe

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Liu, Hongwei, and Houzhu Zhang. "Reducing computation cost by Lax-Wendroff methods with fourth-order temporal accuracy." GEOPHYSICS 84, no. 3 (2019): T109—T119. http://dx.doi.org/10.1190/geo2018-0196.1.

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Explicit time-marching finite-difference stencils have been extensively used for simulating seismic wave propagation, and they are the most computationally intensive part of seismic forward modeling, reverse time migration, and full-waveform inversion. The time-marching step, determined by both the stability condition and numerical dispersion, is a key factor in the computational cost. In contrast with the widely used second-order temporal stencil, the Lax-Wendroff stencil is more cost effective because the time-marching step can be much larger. It can be proved, using theory and numerical tes

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Furumura, Takashi, B. L. N. Kennett, and Hiroshi Takenaka. "Parallel 3-D pseudospectral simulation of seismic wave propagation." GEOPHYSICS 63, no. 1 (1998): 279–88. http://dx.doi.org/10.1190/1.1444322.

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Three‐dimensional pseudospectral modeling for a realistic scale problem is still computationally very intensive, even when using current powerful computers. To overcome this, we have developed a parallel pseudospectral code for calculating the 3-D wavefield by concurrent use of a number of processors. The parallel algorithm is based on a partition of the computational domain, where the field quantities are distributed over a number of processors and the calculation is concurrently done in each subdomain with interprocessor communications. Experimental performance tests using three different st

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Blatter, Daniel, Anandaroop Ray, and Kerry Key. "Two-dimensional Bayesian inversion of magnetotelluric data using trans-dimensional Gaussian processes." Geophysical Journal International 226, no. 1 (2021): 548–63. http://dx.doi.org/10.1093/gji/ggab110.

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SUMMARY Bayesian inversion of electromagnetic data produces crucial uncertainty information on inferred subsurface resistivity. Due to their high computational cost, however, Bayesian inverse methods have largely been restricted to computationally expedient 1-D resistivity models. In this study, we successfully demonstrate, for the first time, a fully 2-D, trans-dimensional Bayesian inversion of magnetotelluric (MT) data. We render this problem tractable from a computational standpoint by using a stochastic interpolation algorithm known as a Gaussian process (GP) to achieve a parsimonious para

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Harkrider, David G. "The early years of computational seismology at Caltech." Bulletin of the Seismological Society of America 78, no. 6 (1988): 2105–9. http://dx.doi.org/10.1785/bssa0780062105.

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