EARTHQUAKE SEISMICITY CATALOG VOLUME 1
              DIRECTORY STRUCTURE

The root level directories for this CD are DATA, DOCUMENT
and SOFTWARE. These directories are described in more 
detail below:

VOLUME1

  DATA - Contains directories organized by regions or
    by catalog source. Two levels of catalogs exist - 
    composite catalogs containing data from multiple 
    sources and single source catalogs. The composite
    catalogs contain several listings for most earth-
    quakes whereas the single source catalogs generally
    have only one listing per event. Composite catalogs
    are from the National Geophysical Data Center 
    (NGDC) with the suffix "no".  

    Most catalogs are in both binary (*.BIN extension) 
    and ASCII (*.DAT extension) format. Each data 
    file also has a corresponding *.FMT file (format 
    description) and *.TAB file (information on the 
    contributor, list of variables with maxima and 
    minima, etc.).  

      CAM - Contains earthquake data for Central America 
        divided into the following directories:
          CAMNO, COSR, HDC, RES, SJS, SSS, SYK.

      CANADA - Contains earthquake data for Canada divided
        into the following directories:
          EASTERN, GENERAL, WESTERN.

      CARIBNO - Contains earthquake data for the Caribbean.

      DNAG - Contains earthquake data from the Decade of
        North American Geology Project.

      MEXICO - Contains earthquake data from Mexico in the
        following directories:
          MEXNO, TAC.

      SUPPLMNT - Contains the files FORMTAP.TXT (description 
        of the NGDC catalogs) and STATIONS.LST (a listing of 
        USGS stations). 
        Also contains supplementary data and information
        divided into the following directories:
          ALGORITH, BIBLIOG, FOCMECH, HYPOEL, HYPOINV, 
          INTENSTY, MOMENTS, TRAVTIME, TSUNAMIS, VOLCANOS, 
          WORSTRES.

      TOPO - Contains 5-minute digital elevation data for 
        the world.

      USA - Contains earthquake data from the United States
        divided into the following directories:
          ALASKA, CALIF, CEUS, CNSS, GENERAL, HAWAII,
          HISTORIC, NEUS, NWUS, SEUS, WASH.

      USGS - Contains PCX files of documentation for the
        USGS catalogs.


  DOCUMENT - Contains TERMS files with definitions of the
    variables on the CDs for use with GeoVu: TERMS.TXT 
    (for PC), TERMS.MAC (for Macintosh), and TERMS.UNX 
    (for UNIX). 


  SOFTWARE - Contains directories of the GeoVu and 
    FREEFORM software.

      FREEFORM - Contains the file README.FRE with
        instructions for converting data into different
        formats. Also contains compressed files of the 
        FREEFORM utilities and documentation files divided 
        by type of platform into the following directories:
          DEC, HP9000, PC, SGI, SUN.

      GEOVU - Contains the files README.GEO and 
        EXERCISES.TXT with instructions on installing and 
        running GeoVu on PC, Macintosh, and UNIX platforms. 
        Also contains compressed files of the GeoVu 
        installation files divided by platform into the 
        following directories: 
          MAC, PC, UNIX_SUN, UNIX_SGI.

        DOC_FILES - Contains README files for the MAC, PC,
          and UNIX platforms. Also contains the following 
          documentation files in DOC, EPS and PDF formats:

            GVQUICK (information on installing GeoVu and 
              getting started),
            GVHELP (GeoVu Users Guide, contains 
              information on more advanced features),
            GVTOOLS (additional information on using 
              GeoVu to access your own data).