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Software For Calculating Earthquake Ground Motions From Finite Faults In Vertically Varying Media
Chapter 85.14 of the IASPEI International Handbook of Earthquake and Engineering Seismology
In 2003 we published in the following references
Spudich, P., and Xu, L., 2003. Software for calculating earthquake ground motions from finite faults in vertically varying media, IASPEI Handbook of Earthquake and Engineering Seismology , Part B, pp. 1633-1634, Academic Press, with associated software on accompanying CD.
Spudich, P , and Xu, L.., 2003. Documentation of software package ISOSYN: Isochrone integration programs for earthquake ground motion calculations, CD accompanying IASPEI Handbook of Earthquake and Engineering Seismology, 72 pp, Academic Press.
Spudich, P ., and Xu, L.., 2003. Documentation of software package COMPSYN: Programs for earthquake ground motion calculations using complete 1-D Green's functions, CD accompanying IASPEI Handbook of Earthquake and Engineering Seismology, 56 pp, Academic Press.
for two FORTRAN 77 software packages, COMPSYN and ISOSYN, for calculating earthquake ground motions caused by ruptures occuring on planar faults of finite spatial extent embedded in vertically varying media.
COMPSYN calculates ground motions using complete synthetic Green's functions, including all rays, near-field and far-field terms, surface waves, leaky modes, etc. However, it does not include the effects of anelastic media.
ISOSYN calculates ground motions using ray theory Green's functions, and is valid at high frequencies (usually > 1 Hz). ISOSYN also contains extensive software for plotting isochrones and other useful quantities on a fault surface.
Both packages were distributed in a zip file named sxv3.11.zip, which contained all necessary FORTRAN source files, as well as source files for visualizing the results of the calculations in device-independent postscript graphic output files. Also included in the packages were documentation and sample input and output files that duplicated several published theoretical seismogram examples. All software required a command-line-oriented operating system and had been successfully run unmodified under DOS and VMS. The version of the software published in the IASPEI Handbook did not run under UNIX or LINUX.
The current version of the software is sxv3.14d, which runs under DOS and UNIX/LINUX. It is much better than sxv3.11 and will handle larger problems, and has fewer minor errors and inaccuracies.
Disclaimer 1: The accuracy of this software is not guaranteed
The software described in this document has been developed for research purposes. The authors have tried to ensure that the basic physics and algorithms of the software are correct. The authors have implemented some tests within the software to verify that the user's input is reasonable. However, because the software was developed as a research tool, there are many possible uses of the software for which it has not been checked, and there are many possible combinations of input parameters that have not been tested. In addition there are some algorithms in the software that give results whose accuracy is controlled by user input, and some algorithms used in this software package produce more accurate results than do other algorithms in this package . It is the complete responsibility of the users of this software to verify that the software produces results that are sufficiently accurate to be acceptable to the user. Although this software has been used by the US Geological Survey and the China Seismological Bureau, no warranty, expressed or implied, is made by the USGS or the United States Government or the China Seismological Bureau as to the accuracy and functioning of the software and related program material, nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS or the CSB in connection therewith. The user is strongly encouraged to use the software to attempt to duplicate published theoretical seismograms calculated for extended earthquake sources. In this way the user will obtain a better appreciation for the accuracy or inaccuracy of the software.
Disclaimer 2: We cannot guarantee to solve all your problem
The users will undoubtedly discover errors in the codes, mistakes in the documentation, and other problems of installation. We hope that the users will notify us of such errors. We will try to offer suggestions to solve user problems when we are notified, but owing to limitations on our time we cannot promise to supply replacement code that repairs every error brought to our attention. Our release of this software is not an implicit promise to maintain the software forever. If the codes malfunction, we ask the user to be sure to read the relevant parts of the documentation thoroughly and carefully consider the error messages before contacting us. In addition, the user should look for error reports and solutions that might be posted on this page.
Disclaimer 3: Some patience and a slight familiarity with FORTRAN are required
You must have a Fortran compiler to use these applications. You are getting the source files, not an executable. Despite the fact that we have successfully compiled these routines on several different machines, operating systems, and compilers, users continue to report to us that their compilers sometimes find minor errors that kill the compilation. If you get a compilation error, you might have to make a slight modification to the Fortran code, or you might have to change compiler switches. You may ask me for advice. Also, these codes can handle very large size problems, but you might have to increase array dimensions to run a large problem. We have tried to include informative error messages when array bounds are exceeded, but you must then know enough Fortran to change an array dimension properly.
If you have read the disclaimers and want to download the software, click the next line:
Yes, I have read the disclaimers and I want sxv3.14d!!
CONTENTS OF THE ZIP FILE:
All files for both packages are contained in a single compressed file sxv3.14d.zip. When you uncompress this file, a complete directory/folder structure containing all files will be created. This directory structure contains all necessary FORTRAN source files, as well as source files for visualizing the results of the calculations in device-independent postscript graphic output files. Also included in the directory structure are documentation and sample input and output files that duplicate several published theoretical seismogram examples. Each subdirectory/folder has a file AAA_READ_ME.TXT that explains the content of the subdirectory/folder. Be sure to read the file AAA_READ_ME.TXT in the top level directory/folder. This file has a section "Quick Start" which will be extremely useful for easy compilation, linking, and running the codes and test examples.