Foundation of china nsfc under contract number 41074100, program for new century excellent. Fourthorder finitedifference psy seismograms 1429 buried source can be inserted within a small homogeneous region of the grid around the source point. They include several types of problems and programming paradigms. Interaction with rough topography causes significant p. The relative orientations of vesicles and phenocrysts in the pumice were analyzed in the software package quant3d. Class orientation, pdes and integral equations, overview of relevant mathematical methods, introduction to fortran programming, opengl redbook codes, introduction to symplectic integration hw1. The hcl operator so produced links directly with any of the hcl optimization algorithms. The numerical scheme is developed from the firstorder system of hyperbolic elastic equations of motion and constitutive laws expressed in particle velocities and stresses. Pdf numerical modeling of wave processes during shelf. Efficient and automatic implementation of the adjoint. The difference of seismogram showed that the second order and high. Contribute to seg2017 tlehall development by creating an account on github. The fourier method required a factor of 20 less computer storage than the equivalent secondorder finitedifference calcu lation. Geller department of earth and planetary physics, faculty of science, tokyo uni.
A survey of techniques for predicting earthquake ground. Optimally accurate second order timedomain finite difference scheme for computing synthetic seismograms in 2d and 3d media nozomu takeuchi, robert j. This code is equipped with a frequencyindependent attenuation model based. First, we used a twodimensional homogeneous model to verify the reflected wave absorption efficiency of our new boundarymatched algorithm. Microseismic source inversion in anisotropic media ubc. A derivative of a function is approximated by the socalled finitedifference formula which uses. The provided seismograms are numerically subtracted trace by trace to furnish the isolated groundroll. Both liaos and lindmans absorbing boundary conditions are implemented for the exterior boundaries to efficiently truncate the computation domain for. A 4th order accurate psv wave staggered grid finite difference. Fourth order finitedifference psv seismograms, geophysics, 5311. The staggered grid finitedifference fd formulation proposed by 27 is the most widely. To investigate the detailed structural properties of the oceanic crust of subducting oceanic plate, we analyzed highfrequency 1 to 16 hz trapped p waves during earthquakes that occurred near the oceanic crust of the philippine sea plate. Geller department of earth and planetary physics, faculty of science, tokyo university, hongo 7.
High order accurate finite difference modeling of seismo. This paper presents a numerical program for the simulation of elastic wave propagation and scattering in threedimensional 3d cylindrical coordinates based on the firstorder velocitystress finitedifference scheme on staggered grids. A firstorder kspace model for elastic wave propagation. Solving the lotkavolterra model using explicit, implicit, and symplectic euler methods, matlab files 2. The fourthorder finitedifference method required twothirds the. Fourthorder finitedifference scheme for p and sv wave. Fourthorder finitedifference psv seismograms nasaads.
Finitedifference elastic modelling below a structured. The viscoelastic wave equation was solved using fourth order in space and second order in time 2931 29. Interpretation of the modeconverted psv wave volume was guided by the interpretation of the pwave volume and proceeded by picking and mapping a number of reflection events in both the orthogonalcomponent volumes components c1 and c2 for phases i and ii, respectively. Mpi provides sourcecode portability of messagepassing programs across a variety of architectures. Read multihole seismic modeling in 3d space and crosshole seismic tomography analysis for boulder detection, journal of applied geophysics on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Simulation of topographic effects on seismic waves from. Parsimonious finitevolume frequencydomain method for 2d. Optimally accurate second order timedomain finite difference scheme for computing synthetic seismograms in 2d and 3d media april 2000 physics of. Staggeredgrid method in 2d psv wave propagation modelling using graphics. Pdf stability and grid dispersion in the psv 4thorder in space, 2ndorder in time. Over the past four or five decades many advances have been made in earthquake groundmotion prediction and a variety of procedures have been proposed. Advances in co2 capture and storage technology results 20042009 edited by lars eide. Psv wave finite difference algorithm, fourth order spatial accu.
Please consider these following points, when running the solver. Finitedifference elastic modelling below a structured free surface peter m. If the address matches an existing account you will receive an email with instructions to reset your password. Choose the order of the approximation for example, the 4th order. Spectralelement simulations of elastic wave propagation. The fourth order forward finitedifference operator, e. Mpi is a public domain software which is available in fortran and c. Free and smooth boundaries in 2d finitedifference schemes for transient elastic waves b. Levander, fourthorder finitedifference psv seismograms, geophysics 53. I describe the properties of a fourthorder accurate space, secondorder accurate time, twodimensional psv finitedifference scheme based on the madariagavirieux staggeredgrid formulation. Finite difference time domain simulations of dynamic. Some of these procedures are based on explicit physical models of the earthquake source, travelpath and recording site while others lack a strong physical basis and seek only to replicate observations.
Threedimensional 3d finite difference fd simulations were performed for southern vancouver island using an anelastic wave propagation awp simulation code awpodc. Summary electromagnetic em heating is becoming a popular method for heavyoil recovery because of its costefficiency and continuous technological improvements. Psv wave timedomain finitedifference algorithm with realistic damping and a combined study of effects of sediment rheology and basement focusing, acta geophysica, 62, 12141245. Axisymmetric modeling has often been used in global seismology to r. Optimal staggeredgrid finitedifference schemes based on least. Considering a seismically active leech river valley fault. Sahar 2014 3d viscoelastic finitedifference code and modelling of basement focusing effects on ground motion characteristics, computational. The text also contains a users guide to the fortran 95 program package 1dfd which is. This becomes a serious limitation for datuming data acquired using 3d conventional landacquisition layouts, because of the typical sparse spacing of either the sources or receivers. Sedimentary rocks and shales in particular are known to be anisotropic, sometimes strongly so, and hydraulic fracturing is now common practice in shale plays to enhance the extraction of hydrocarbons. The medium model was created based on topography profile of selected line intersecting mount merapi, where 200 meters thick lowvelocity layer has been added. A finite difference program simulates the elastic wave propagation in the model, providing both an acoustic seismogram and elastic one which contains the groundroll and also the acoustic response. The distinct trapped p waves observed by the dense seismic network of the kantotokai region, japan, did not show any.
The source is the same as previously described and is located at, m with a time step of 0. Read summation by parts operators for finite difference approximations of secondderivatives with variable coefficients, journal of scientific computing on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Common datuming approaches, like the kirchhoff or finitedifference methods, require reasonable sampling of the sources and receivers. Parallel 3d viscoelastic finite difference seismic modelling. A pseudospectral model of linear elastic wave propagation is described based on the first order stressvelocity equations of elastodynamics. Automatic code generation package for finite difference. Numerical modeling of wave processes during shelf seismic exploration article pdf available in procedia computer science 96. Several results and images obtained through commercial programs and through inhouse software developments illustrate the topics discussed. The finitedifference method for seismologists nuquake.
Finite difference modeling of wave progpagation in. A number of industries in the netherlands, among which chemical plant and pipeline owners as well as nde service companies have initiated a joint industry project to develop a model and corresponding software tool podgenerator to assess. Fourthorder finitedifference psv seismograms levander, alan r. In this study, a numerical modelling of p sv wave propagation in elastic heterogeneous medium has been done using fourth order finite difference method. Fourth order finitedifference psv seismic seismograms. Global shwave propagation using a parallel axisymmetric. The 2d finite difference numerical modelling of psv wave. Seismograms article about seismograms by the free dictionary. Geo 2008 conference abstracts geoarabia geoscienceworld. Paralel 3d viscoelastic finite difference seismic modelling. Summation by parts operators for finite difference. Velocity increase in the uppermost oceanic crust of.
Staggered grid method in 2d psv wave propagation modelling using graphics. The base elastic physical model representative of the local geology beneath. Carbon dioxide capture for storage in deep geologic formations results from the co2 capture project volume three. Virieux, free and smooth boundaries in 2d finitedifference schemes for transient elastic waves, geophysical journal international, volume 172, issue 1. Mge2011kg07, the knowledge innovation program of chinese academy of sciences no. Please redirect your searches to the new ads modern form or the classic form. One of the ways to understand the hydraulic fracturing process is through the microearthquakes that it generates. To make use of the efficiency of network computers a parallel 3d viscoelastic finite difference fd code is implemented which allows to distribute the work on several pcs or workstations connected via standard ethernet in an inhouse network. Pdf a comparison of secondorder and highorder of finite. We have developed an opensource software package, opensource seismic wave propagation code openswpc, for parallel numerical simulations of seismic wave propagation in 3d and 2d psv and sh viscoelastic media based on the finite difference method in localtoregional scales. Download limit exceeded you have exceeded your daily download allowance. Superposition method for modelling boundaries between. Finite difference, a python software package that automates the transformation of mathe. For iterative calculations of synthetic seismograms with limited computer resources, a fast and accurate modeling method is needed.
Accuracy of the staggeredgrid finitedifference method of the. Levanderfourthorder finitedifference psv seismograms. Accuracy of finitedifference modeling of the acoustic wave equation. Fourthorder finitedifference psv seismograms, geophysics, 5311. The program is applied to onelayer medium and complex medium marmousi2. Optimally accurate secondorder timedomain finite difference scheme for the elastic equation of motion. Anders and sjogreen, bjorn, abstractnote here, we develop a numerical method for simultaneously simulating acoustic waves in a realistic.
This program is able to calculate the soil amplification, based on. In this study, a numerical modelling of psv wave propagation in elastic heterogeneous medium has been done using fourth order finitedifference method. History matching of electromagnetically heated reservoirs. The software package blob3d was used to quantify vesicle sizes, shapes, and distributions of four samples of the white pumice from highresolution xray computed tomography hrxct scans. Mahidol university center for scientific computing mcsc. Fwm2da is a fortran program for 2d finitedifference timedomain. The difficulty for the purposes of this report is that the software here has as yet not. Since the longtime instability only affects the late stage of the simulation, while impacts very little on the simulation accuracy at the.
Wavefield snapshots and synthetic seismograms are produced to illustrate the. Fourthorder finitedifference pw seismograms 1427 where ia and w are the displacement components in x and z, u, and w, are the particle velocities, rij are the stresses, h and u are the lame parameters with u the rigidity, and p is the density. Pdf stability and grid dispersion of the psv 4thorder staggered. The model is extrapolated outside the volume of interest in all directions about two times the model length to avoid any edge effects. It exploits the relationship that the viscosity of hydrocarbons decreases for increasi.
28 305 1253 489 1106 941 1259 17 302 182 339 1338 1103 1179 516 141 388 1071 1084 378 801 1288 1110 1411 1254 534 450 844 1060 771 1498 1097 421 961 399 296 116 1023 1390 132 159 536 1190 280 9 1248 1459 572