U.S. Geological Survey General Earthquake Observation System National Strong Motion Program

GEOS Data FTP Site

This site contains earthquake and aftershock data collected by the United States Geological Survey (USGS) General Earthquake Observation System (GEOS) project in Menlo Park, California.

The digital recordings can be transferred using Netscape Navigator or Microsoft Explorer or via anonymous FTP from https://ca.water.usgs.gov/nsmp/GEOS/.

File Format Assistance

The following are provided to assist in interpreting the binary file format.

  • HEADER.DOC - description of data file headers
  • BBFILE.C - machine-independent C program source code for reading binary GEOS data, outputting ASCII

    The following are for use on PCs only. To use, save to disk first.

  • GEOSDEMO.EXE or GEOSDEMO.EXE (http) - Windows95 (98/NT4+) plotting demo for binary GEOS data
  • 3472355P4.GAO - sample binary GEOS file that the above plotting program uses by default
  • BBFILE.EXE or BBFILE.EXE (http) - compiled PC-DOS version of C program for reading binary GEOS data, outputting ASCII

    Note: BBFILE.EXE outputs only to the screen and now (as of 22-Apr-2014) recognizes long filenames so in order to use this to create ASCII files from online data sets use the syntax:
    BBFILE 3472355P1.GAO >> 3472355P4.GAO.TXT
    where 3472355P1.GAO is the filename of the binary GEOS data file, the >> redirects the screen output to a file, and 3472355P4.GAO.TXT is a legitimate DOS filename for the output ASCII data.

    U.S. Department of the Interior
    The USGS Home Page is at http://www.usgs.gov
    The USGS Geologic Division Home Page is at http://geology.usgs.gov
    The USGS National Strong Motion Program Home Page is at http://earthquake.usgs.gov/monitoring/nsmp

    The GEOS Home Page is at /GEOS/geos.html
    The URL of this page is /GEOS/data.html
    e-mail: glassmoyer@usgs.gov
    or address:
    Gary Glassmoyer
    345 Middlefield Road M/S 977
    Menlo Park, California 94025