See online documentation

Application to Download 3D focal mechanisms Authors: Keith A. Labay and Peter J. Haeussler Utilization: View earthquake focal mechanism symbols three dimensionally Platform: Windows Interface: ArcScene® 9.x Input: A GIS point dataset of earthquake locations containing strike, dip, and rake values for a nodal plane of each earthquake Examples: Available at website Manual: Available at website Download: See online documentation
3D Focal Mechanisms is a tool for viewing earthquake focal mechanism symbols a few dimensionally. This tool operates within the Environmental Systems Research Institute (ESRI®) GIS software program ArcScene® 9.x. The program requires as input a GIS point dataset of earthquake locations containing strike, dip, and rake values for a nodal plane of each earthquake. Other information, such as depth and magnitude of the earthquake Microsoft Office Ultimate 2007, may also be included in the dataset. By default for each focal point, 3DFM will create a black and white sphere or “beach ball” that is oriented based on the strike, dip, and rake values. If depth values for each earthquake are included, the focal symbol will also be placed at its appropriate location beneath the Earth's surface.
3D velocity modeling Authors: Cliff Thurber (most recently modified by Donna Eberhart-Phillips) Platform: Unix Other: arc2cnv.c C code to convert phase data from hypoinverse archive format Download: simulps12.for (197k), simin.tar.Z (79k)
simulps12.for: Fortran code (VMS compatible) for 3-D velocity model determination and hypocentral location with local earthquake data. Full inversion, not tomography, this is the program written by Cliff Thurber and modified by others (most recently Donna Eberhart-Phillips).

simin.tar.Z: Example input files for simulps12.for, including the VMS command file. These don't form a complete set that go together, but do show all the different types of input files. This a Unix tar compressed with the Unix compress command.
cleanstrain+ Author: John Langbein Utilization: Analyze strainmeter data in order to estimate tidal coefficients and pressure admittance Platform: Unix and/or Mac OS X (Requires Fortran compiler for Mac OS X) Interface: Command line Input: Time series of strainmeter data Output: Cleaned-up strainmeter data Docs: Online documentation: installation, manual, examples Download: cleanstrain+
Cleanstrain+ is a program to process strainmeter data. This code will simultaneously estimate the tidal constituents, pressure admittance, offsets, rate changes, and other terms using least-squares but, importantly, incorporating the temporally correlated nature of strain data (that is, the power spectra is red).
CLUSTER2000 Author: Paul Reasenberg Use: Identify clusters (e.g., aftershocks) in an earthquake catalog Platform: Unix, or any platform with Fortran Interface: Parameters read from standard input Input: Catalog text file Output: Several text files Docs: Comments in source code Download: Fortran source code (35k), Makefile (233b)
CLUSTER2000 recognizes clusters in space-time in an earthquake catalog. It is intended for use in removing aftershocks or "declustering" the catalog. The methods used are described in "Second-Order Moment of Central California Seismicity, 1969-1982" (P. Reasenberg, JGR v.90., pp.5479-5495, 1985). The current version (CLUSTER2000x) reads catalogs in a variety of standard formats. However, it is not fully Y2000 compatible. While it reads the Y2K formats for HYPOINVERSE and HYPO71 Windows 7 Ultimate, CLUSTER2000x requires all data to belong to one century.
Coulomb 3 Authors: Shinji Toda, Ross Stein, Jian Lin, Volkan Sevilgen Utilization: Stress-triggering software program Platform: Matlab on Windows, Mac or Unix Interface: Menu driven Output: Grahics and text Manual: Online documentaiton Download: See online documentation
Coulomb 3 is designed to investigate Coulomb stress changes on mapped faults and earthquake nodal planes, and is intended both for publication-directed research and for university teaching and instruction.

One can calculate static displacements (on any surface or at GPS stations), strains, and stresses caused by fault slip, magmatic intrusion or dike expansion. Problems such as how an earthquake promotes or inhibits failure on nearby faults, or how fault slip or dike expansion will compress a nearby magma chamber, are germane to Coulomb. Geologic deformation associated with strike-slip faults, normal faults, or fault-bend folds is also a useful application. Calculations are made in an elastic halfspace with uniform isotropic elastic properties following Okada [1992].

We believe that one learns best when one can see the most and can explore alternatives quickly. So the principal feature of Coulomb is ease of input, rapid interactive modification, and intuitive visualization of the results. The program has menus, sub-menus, check-items, and dialogue boxes to ease operation. The internal graphics are suitable for publication, and can be easily imported into illustration or animation programs for further enhancements.
Earthquake Directivity Model Author: Paul Spudich Utilization: Calculate seismic directivity Platform: Any platform running MATLAB Interface: MATLAB command line Input: Function calling arguments Output: .txt and .mat files Examples: Contained in downloadable file Download: See online documentation
Isodirect1 is a MATLAB-language function for modeling seismic directivity at user-selected sites around a user-defined fault. Isodirect1.m implements the Spudich and Chiou (Earthquake Spectra, 2008) directivity model. The results of isodirect1.m should be combined with the ground motion predictions of a non-directive predictive model like any of the four NGA models. Input to isodirect1.m consists of the coordinates of a set of sites where directivity predictions are desired, the coordinates of the corners of one or more fault segments, hypocenter location, earthquake magnitude and slip rake, desired periods for output. Output consists of directivity amplifications for all input sites, plus many intermediate results, such as the points on the fault closest to the input sites, rupture distances, etc.
Earthquake Information Distribution System (EIDS) Contacts: Jeremy Fee and Dave Oppenheimer Utilization: Distribution of earthquake data over the Internet Platform: Any O/S that supports Java Interface: Runs in background Output: Files containing information about earthquakes Download: See online documentation
The Earthquake Information Distribution System (EIDS) provides a method for receiving earthquake data over the Internet in near-real time. EIDS replaces the Quake Data Distribution System (QDDS) and provides either CUBE or EQXML formatted output messages.
FPFIT, FPPLOT and FPPAGE Authors: Paul Reasenberg and David Oppenheimer Use: Calculate and plotfault-plane solutions from first-motion data Platform: Unix Interface: Command line Output: Grahics and text Examples: Included in dowload file Manual: Online documentation and USGS Open-File report Tutorial: Included in dowload file Download: fpfit_source.tar (1.3 MB)
FPFIT is a Fortran program that computes double-couple fault plane solutions from P-wave first motion data using a grid search method. The companion programs FPPLOT and FPPAGE plot the results on stereo nets for interactive viewing or for printing. There are additional programs in the package to create summary tables and to plot P&T axes for suites of mechanisms on stereo nets.
Ground Motion Parameter Calculator Author: E.V. Leyendecker, Arthur Frankel, Kenneth Rukstales, Eric Martinez, Nicolas Luco, Jeremy Fee, Ned Field Office Standard 2010, Nitin Gupta, Vipin Gupta Utilization: Calculate estimated ground motions for building design Platform: Any O/S that supports Java Interface: Java Graphic User Interface (GUI) Output: Images and Text Download: See online documentation
Hazard curves, uniform hazard response spectra, and design parameters are available for sites in the 50 states of the United States, Puerto Rico and the U.S. Virgin Islands. Additionally, design parameters are available for Guam and American Samoa.
HASH 1.2 Authors: Jeanne Hardebeck and Peter Shearer Utilization: Calculates earthquake focal mechanisms Platform: Unix Interface: Command line / text input files Output: Text files Examples: Included in download file Manual: PDF included in download file Download: hash.v1.2.tar.gz (1 MB)
HASH is a Fortran 77 code that computes double-couple earthquake focal mechanisms from P-wave first motion polarity observations, and optionally S/P amplitude ratios. HASH is designed to produce stable high-quality focal mechanisms, and tests the solution sensitivity to possible errors in the first-motion input and the computed take-off angles. The technique is described by Hardebeck and Shearer (BSSA 92, pp. 2264-2276, 2002.) Examples are provided for data in FPFIT input format. The code is designed to be as input-format independent as possible, so only minor editing is needed to use data in other formats.
hypoDD Author: Felix Waldhauser Maintenance: Felix Waldhauser, Bruce Julian, Bill Ellsworth, Keith Richards-Dinger Use: Implements the double-difference earthquake location algorithm Platform: Unix Interface: Command line / text input files Output: Text files Examples: Examples, More examples Manual: PDF and PostScript files in tar file Download: HYPODD_1.0.tar.gz (14 MB)
HypoDD is a Fortran computer program package for relocating earthquakes with the double-difference (DD) algorithm of Waldhauser and Ellsworth (2000). The DD technique takes advantage of the fact that if the hypocentral separation between two earthquakes is small compared to the event-station distance and the scale length of velocity heterogeneity, then the ray paths between the source region and a common station are similar along almost the entire ray path (Frechet, 1985; Got et al., 1994).
HYPOINVERSE earthquake location program Author: Fred Klein Utilization: Locate earthquakes and determine magnitudes in a local or regional seismic network Platform: Unix or Vax, Fortran source code Interface: Command line, files or keyboard Input: ASCII text Output: ASCII text Examples: Sample runs in distribution directory Manual: Extensive open-file document, in Microsoft Word and postscript formats Tutorial: Simple examples included in manual Download: hyp2000 (2 MB)
HYPOINVERSE2000 determines earthquake locations and magnitudes from seismic network data like first-arrival P and S arrival times, amplitudes and coda durations. The present version HYPOINVERSE2000 is in routine use by the Hawaiian Volcano Observatory, The Northern California Seismic Network, the Nevada network, and many other networks. It is the standard location program supplied with the Earthworm seismic acquisition and processing system and has thus gotten wide use. Crustal models can be multiple to cover different regions, and either flat layer or flat layer with linear velocity gradients. It is Y2000 compatible.
MacR1D Author: Jim Luetgert Utilization: 1-D travel time calculation Platform: Mac OS 9 Interface: Menu driven Output: PICT file Download: MacR1D.zip
MacR1D is a one-dimensional seismic travel-time calculator for Macintosh. Travel-times vs distance are calculated for P and S arrivals (sorry, no converted phases or multiples) for sources at any depth. These may be compared to observed travel-times. This is a very quick way to define 1-d velocity models from observed arrival pics.
MacRay Author: Jim Luetgert Use: General purpose 2-D seismic seismic ray tracer Platform: Mac OSX or PC Interface: Menu driven Output: PICT file Examples: Included in download file Manual: MS Word document included in download file Download: Mac OSX - MacRay_V2 (1.9 Mb); PC - RAY84PC (1.2 Mb)
MacRay is a general purpose two-dimensional seismic ray-tracer for Macintosh. Originally written to trace rays through 2-dimensional p-wave models, MacRay has grown to support 2-d models defined in Vp, Vs and density. In addition to being able to model the full range of simple to complex raypaths, the 2-d gravity response of the model may also be calculated. For surveys providing seismic P, S and converted wave arrivals in addition to gravity measurements, the full suite of physical properties may be modeled; Vp, Vs, density, Poisson's ratio, Vp/Vs, Shear modulus, Bulk modulus, Young's modulus, Lame's parameter, lithostatic pressure.

With the addition of an assumed or measured geothermal gradient, we can model the pressure and temperature conditions at any point in our earth model. A recent addition to MacRay allows you to define the features of a pressure-temperature diagram (e.g. metamorphic grade, solidus) and map those P-T regions back into the earth model.

The PC version is a port of Ray84 written for Vax. It was ported by Hans Thybo of Copenhagen University, Denmark.
OpenSHA Authors: Ned (Edward) Field (USGS/SCEC) Windows 7 Pro Product Key, Nitin Gupta (USC/SCEC), and Vipin Gupta (USC/SCEC) Utilization: Open-source seismic hazard analysis Platform: Any O/S that supports Java Manual: See online documentation Download: See online documentation
OpenSHA is an effort to develop object-oriented, web- & GUI-enabled, open-source, and freely available code for conducting Seismic Hazard Analyses (SHA). Our goal is to provide a framework where any arbitrarily complex (e.g., physics based) earthquake-rupture forecast, ground-motion Office 2010 Home And Student, or engineering-response model can "plug in" for analysis without having to change what’s being plugged into.
PQLX Authors: Dan McNamara, Richard Boaz Usage:Evaluate seismic station performance Platform:Unix Interface:GUI Input:standard seismic data formats Output:MySQL database, images, plots Examples: See sample data and response file Download: See online documentation
PQLX is open-source software system for evaluating seismic station performance and data quality. The computer software consists of a server and client but also includes data extraction and manipulation tools. Given waveform data and instrument response files, PQLX server calculates trace statistics, Power Spectral Densities (PSD), and Probability Density Functions (PDF) and writes the results to a MySQL database for quick access.
Probabilistic Seismic Hazard Calculation Application Authors: Art Frankel and Chuck Mueller Use: Programs used to construct the 1996 National Seismic Hazard Maps Platform: Unix, Fortran source codes, some C subroutines Interface: command line Download: See online documentation
Computer codes used to construct the 1996 U.S. National Seismic Hazard Maps.
Quake Data Distribution System (QDDS) Contacts: Dave Oppenheimer Usage: Distribution of earthquake data over the Internet Platform: Any O/S that supports Java Interface: Runs in background Output: Files containing information about earthquakes Examples: Included in dowload file Download: QDDS has been replaced by EIDS
The Quake Data Distribution System (QDDS) provides a method for distributing earthquake data over the Internet in near-real time using a structure similar to a classical client-server system called a hub-leaf system. Leaves are of two types — transient and permanent. Transient leaves can only receive messages distributed by the hubs. Transient leaves can self-register with the hubs and immediately begin receiving earthquake information. Permanent leaves (i.e., seismic networks) can also originate information and send it to one or more hubs for redistribution to permanent and transient leaves.

QDDS has been replaced by EIDS
Quake Data Merge Real Time Merged Catalog (QDM) Contacts: Alan Jones and Dave Oppenheimer Usage: Produces a single, merged earthquake catalog using the most authoritative earthquake information Platform: Any O/S that supports Java Interface: Runs in background Output: Files containing information about earthquakes Examples: Included in dowload file Download: See online documentation
The Quake Data Merge Real Time Merged Catalog (QDM) software program receives earthquake summary information and additional text from seismographic networks, eliminates duplicate and redundant information reported by different seismic networks, and produces a single, authoritative earthquake catalog. The process to generate this "composite" catalog follows selection rules set out by the ANSS to determine which earthquake information has the most authoritative information. This catalog can be used as input to other applications that require access to earthquake information in near-real time. The most likely method for receiving the event and text information is through the QDDS system.
SATSI Authors: Jeanne Hardebeck and Andy Michael Utilization: Spatially and/or temporally varying stress field from focal mechanisms Platform: Unix (or any platform with C) Interface: Command line / text input files Output: Text files Examples: Included in download file Download: SATSI.tar (360k)
SATSI (Spatial And Temporal Stress Inversion) is a modified version of Michael's (JGR 1984, 1987) code that inverts focal mechanism data for a spatially and/or temporally varying stress field. The inversion finds the least complex stress field model that is consistent with the data. It uses an adaptive smoothing method that discriminates between variations that are or aren't strongly required by the data and retains only variations that are well-resolved. The technique is described and validated in Hardebeck and Michael (JGR 111, B11310, doi:10.1029/2005JB004144, 2006.) The tar file contains C codes implementing the inversion method for 2D and 4D stress fields (1D and 3D fields can be treated as simplified cases), and example input data and Perl scripts.
ShakeCast “Lite” – ShakeMap RSS Reader Authors: Kuo-Wan Lin and David Wald Use: Automated ShakeMap delivery to users, facilitating use of ShakeMap products and post-download post-commands (script startup) Platform: Unix, Windows Interface: Scripts / text configuration files Output: ShakeMap products and post-commands (Google Earth, Browser, etc.) Examples: Available at website Manual: Included in download file Download: See online documentation
Delivers maps of areas affected by an earthquake. Areas of interest can be defined, and shaking thresholds can be set to trigger automatic notifications. Easy to integrate with in-house systems.
Slick Package Author: Andy Michael Utilization: Stress inversion from slip data Platform: Unix, PC (or any platform with C) Interface: Command line, can be run as batch mode Bound Program: Onnet, Stereonet plotting package Output: Text, graphics via onnet stereonet plotting program Examples: Included in download file Manual: ASCII Text and Postscript files in included in download file Tutorial: Included in download file Download: Unix - stress.tar.Z (41k); PC - stresspc.zip (160k)
The slick package uses fault slip data (either field observations or from focal mechamism) to find the stress tensor that best explains the observations. Inputs are the orientation and slip direction of a set of fault planes. Outputs are the oreintation and shape of the stress ellipsoid, including confidence regions, and statistics used to judge the success of the inversion. This method uses the linear inversion agorithm and non-parametric bootstrap statistics.

Unix: The code to invert fault slip data for the stress tensor. format is compressed tar. To extract on a Unix system use the command % zcat stress.tar.Z | tar xf - It will expand into a number of files in your current directory. You also need to get the onnet plotting package.

PC: Same as stress.tar.Z but containing Leigh House of Los Alamos' conversion of the computer software to PC compatibility. The zip was done with Zip 1.0 (29 September 1991).
Slope Performance During an Earthquake Authors: Randall W. Jibson and Matthew W. Jibson Usage: Using Newmark’s method and simplified decoupled analysis to model slope performance during earthquakes Platform: Any O/S that supports Java Interface: Java GUI Manual: Available in download file Download: See online documentation
This program package is designed to allow users to conduct Newmark sliding-block analysis and simplified decoupled analysis to estimate co-seismic slope displacements.
strainz17: Earthquake strains and rotations Author: Paul Spudich Usage: Calculate strains and rotations of an array Platform: Any platform running MATLAB Interface: MATLAB command line Input: Seismograms from several stations, via function's calling arguments Output: .txt, .mat, and .pdf files Examples: Contained in downloadable file Download: See online documentation
Strainz17.m is a MATLAB-language function for deriving the best-fitting uniform strain tensor and rigid body rotation as functions of time, based on ground displacement or velocity recordings made on an array of sensors. Strainz17.m implements the theory in Spudich et al. (J. Geophys. Res., 1995) and Spudich and Fletcher (Bull. Seismol. Soc. Am., 2008). In addition to the strainz1717.m function, the downloadable file provides sample input and output data, and it provides functions for running the sample test cases.
VISCO1D Author: Fred Politz Use: Calculate displacements/velocities and strain/strain rates Platform: Unix, Fortran source codes Interface: Command line Input: Viscoelastic model parameters, finite-fault source parameters Output: Viscoelastic-relaxation deformation fields at earth's surface or at depth Manual: 1.3 Mb .pdf file Download: 2.1 Mb .zip file
VISCO1D-v3 is a program package to calculate quasi-static deformation on a layered spherical Earth from a specified input source (fault plane parameters) at specified points on the surface or at depth.

It uses a spherical harmonic expansion of the global deformation field and evaluates a sum of viscoelastic normal modes in a semi-analytic computation.

Version 3 of VISCO1D-v3 is now available (updated on Jan. 29, 2007).