Skip Links

USGS - science for a changing world

Opne-File Report 00-509

SMSIM—Fortran Programs for Simulating Ground Motions from Earthquakes: Version 2.0—a Revision of OFR 96–80–A

By David M. Boore

Thumbnail of and link to report PDF (928 kB)Introduction

A simple and powerful method for simulating ground motions is based on the assumption that the amplitude of ground motion at a site can be specified in a deterministic way, with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to distance from the source. This method of simulating ground motions often goes by the name "the stochastic method." It is particularly useful for simulating the higher-frequency ground motions of most interest to engineers, and it is widely used to predict ground motions for regions of the world in which recordings of motion from damaging earthquakes are not available. This simple method has been successful in matching a variety of ground-motion measures for earthquakes with seismic moments spanning more than 12 orders of magnitude. One of the essential characteristics of the method is that it distills what is known about the various factors affecting ground motions (source, path, and site) into simple functional forms that can be used to predict ground motions. SMSIM is a set of programs for simulating ground motions based on the stochastic method.

This Open-File Report is a revision of an earlier report (Boore, 1996) describing a set of programs for simulating ground motions from earthquakes. The programs are based on modifications I have made to the stochastic method first introduced by Hanks and McGuire (1981). The report contains source codes, written in Fortran, and executables that can be used on a PC. Programs are included both for time-domain and for random vibration simulations. In addition, programs are included to produce Fourier amplitude spectra for the models used in the simulations and to convert shear velocity vs. depth into frequency-dependent amplification. The revision to the previous report is needed because the input and output files have changed significantly, and a number of new programs have been included in the set.

First posted December 21, 2000

For additional information, contact:
Earthquake Science Center, Menlo Park, CA
U.S. Geological Survey
345 Middlefield Road MS 977
Menlo Park, California 94025

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Boore, David M., 2000, SMSIM—Fortran Programs for Simulating Ground Motions from Earthquakes: Version 2.0—a Revision of OFR 96–80–A: U.S. Geological Survey Open-File Report 00-509, 57 pp.,




Program Overview

Compilation and Modification

SMSIM Programs

Site-Amplification Programs



Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Wednesday, December 07, 2016, 06:16:05 PM