Paralel 3d viscoelastic finite difference seismic modelling. The 2d finite difference numerical modelling of psv wave. 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. Levander, fourthorder finitedifference psv seismograms, geophysics 53. Foundation of china nsfc under contract number 41074100, program for new century excellent. Fourthorder finitedifference psv seismograms, geophysics, 5311. Accuracy of the staggeredgrid finitedifference method of the. The program is applied to onelayer medium and complex medium marmousi2. 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. Solving the lotkavolterra model using explicit, implicit, and symplectic euler methods, matlab files 2.
Fourth order finitedifference psv seismograms, geophysics, 5311. Common datuming approaches, like the kirchhoff or finitedifference methods, require reasonable sampling of the sources and receivers. Velocity increase in the uppermost oceanic crust of. Choose the order of the approximation for example, the 4th order.
I describe the properties of a fourthorder accurate space, secondorder accurate time, twodimensional psv finitedifference scheme based on the madariagavirieux staggeredgrid formulation. Sahar 2014 3d viscoelastic finitedifference code and modelling of basement focusing effects on ground motion characteristics, computational. The difference of seismogram showed that the second order and high. Axisymmetric modeling has often been used in global seismology to r. A survey of techniques for predicting earthquake ground. The source is the same as previously described and is located at, m with a time step of 0. This program is able to calculate the soil amplification, based on. Summation by parts operators for finite difference.
For iterative calculations of synthetic seismograms with limited computer resources, a fast and accurate modeling method is needed. Mpi is a public domain software which is available in fortran and c. Fourthorder finitedifference scheme for p and sv wave. Parallel 3d viscoelastic finite difference seismic modelling. High order accurate finite difference modeling of seismo. Finite difference modeling of wave progpagation in. 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. Geller department of earth and planetary physics, faculty of science, tokyo uni. Finitedifference elastic modelling below a structured free surface peter m. First, we used a twodimensional homogeneous model to verify the reflected wave absorption efficiency of our new boundarymatched algorithm. The difficulty for the purposes of this report is that the software here has as yet not. Fourthorder finitedifference psy seismograms 1429 buried source can be inserted within a small homogeneous region of the grid around the source point.
Mahidol university center for scientific computing mcsc. Optimally accurate second order timedomain finite difference scheme for computing synthetic seismograms in 2d and 3d media april 2000 physics of. The fourthorder finitedifference method required twothirds the. Mpi provides sourcecode portability of messagepassing programs across a variety of architectures. Pdf a comparison of secondorder and highorder of finite. 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. Optimally accurate second order timedomain finite difference scheme for computing synthetic seismograms in 2d and 3d media nozomu takeuchi, robert j.
Fwm2da is a fortran program for 2d finitedifference timedomain. A firstorder kspace model for elastic wave propagation. A derivative of a function is approximated by the socalled finitedifference formula which uses. A 4th order accurate psv wave staggered grid finite difference.
Efficient and automatic implementation of the adjoint. The provided seismograms are numerically subtracted trace by trace to furnish the isolated groundroll. Pdf stability and grid dispersion in the psv 4thorder in space, 2ndorder in time. 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. Finitedifference elastic modelling below a structured. Staggered grid method in 2d psv wave propagation modelling using graphics. Summary electromagnetic em heating is becoming a popular method for heavyoil recovery because of its costefficiency and continuous technological improvements.
Download limit exceeded you have exceeded your daily download allowance. The hcl operator so produced links directly with any of the hcl optimization algorithms. Microseismic source inversion in anisotropic media ubc. Pdf numerical modeling of wave processes during shelf. Simulation of topographic effects on seismic waves from. Wavefield snapshots and synthetic seismograms are produced to illustrate the. 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. Fourth order finitedifference psv seismic seismograms. Geller department of earth and planetary physics, faculty of science, tokyo university, hongo 7. In this study, a numerical modelling of p sv wave propagation in elastic heterogeneous medium has been done using fourth order finite difference method.
Mge2011kg07, the knowledge innovation program of chinese academy of sciences no. They include several types of problems and programming paradigms. Class orientation, pdes and integral equations, overview of relevant mathematical methods, introduction to fortran programming, opengl redbook codes, introduction to symplectic integration hw1. Staggeredgrid method in 2d psv wave propagation modelling using graphics.
Please redirect your searches to the new ads modern form or the classic form. Carbon dioxide capture for storage in deep geologic formations results from the co2 capture project volume three. The relative orientations of vesicles and phenocrysts in the pumice were analyzed in the software package quant3d. The finitedifference method for seismologists nuquake. Threedimensional 3d finite difference fd simulations were performed for southern vancouver island using an anelastic wave propagation awp simulation code awpodc. Parsimonious finitevolume frequencydomain method for 2d. The fourier method required a factor of 20 less computer storage than the equivalent secondorder finitedifference calcu lation. A pseudospectral model of linear elastic wave propagation is described based on the first order stressvelocity equations of elastodynamics. Finite difference, a python software package that automates the transformation of mathe. 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. Accuracy of finitedifference modeling of the acoustic wave equation. Levanderfourthorder finitedifference psv seismograms. Theodorus permana graduate student tohoku university.
Global shwave propagation using a parallel axisymmetric. Fourthorder finitedifference psv seismograms nasaads. Anders and sjogreen, bjorn, abstractnote here, we develop a numerical method for simultaneously simulating acoustic waves in a realistic. Interaction with rough topography causes significant p. Please consider these following points, when running the solver. The viscoelastic wave equation was solved using fourth order in space and second order in time 2931 29. The distinct trapped p waves observed by the dense seismic network of the kantotokai region, japan, did not show any. Considering a seismically active leech river valley fault. 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. 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.
Automatic code generation package for finite difference. 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. 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. It exploits the relationship that the viscosity of hydrocarbons decreases for increasi. Virieux, free and smooth boundaries in 2d finitedifference schemes for transient elastic waves, geophysical journal international, volume 172, issue 1. The base elastic physical model representative of the local geology beneath. 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. The fourth order forward finitedifference operator, e. Both liaos and lindmans absorbing boundary conditions are implemented for the exterior boundaries to efficiently truncate the computation domain for. History matching of electromagnetically heated reservoirs.
Optimal staggeredgrid finitedifference schemes based on least. This code is equipped with a frequencyindependent attenuation model based. One of the ways to understand the hydraulic fracturing process is through the microearthquakes that it generates. 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. In this study, a numerical modelling of psv wave propagation in elastic heterogeneous medium has been done using fourth order finitedifference method.
Superposition method for modelling boundaries between. Advances in co2 capture and storage technology results 20042009 edited by lars eide. Fourthorder finitedifference psv seismograms levander, alan r. Optimally accurate secondorder timedomain finite difference scheme for the elastic equation of motion. Several results and images obtained through commercial programs and through inhouse software developments illustrate the topics discussed. The numerical scheme is developed from the firstorder system of hyperbolic elastic equations of motion and constitutive laws expressed in particle velocities and stresses. Free and smooth boundaries in 2d finitedifference schemes for transient elastic waves b. The staggered grid finitedifference fd formulation proposed by 27 is the most widely.
Spectralelement simulations of elastic wave propagation. If the address matches an existing account you will receive an email with instructions to reset your password. Numerical modeling of wave processes during shelf seismic exploration article pdf available in procedia computer science 96. Geo 2008 conference abstracts geoarabia geoscienceworld. Psv wave finite difference algorithm, fourth order spatial accu. The text also contains a users guide to the fortran 95 program package 1dfd which is. The medium model was created based on topography profile of selected line intersecting mount merapi, where 200 meters thick lowvelocity layer has been added.