etopo5.northern.bat.Z 8.3 Mb etopo5.southern.bat.Z 7.9 Mb These two files contain worldwide bathymetric and elevation data in meters with a 5 minute by 5 minute latitude/longitude data density. The data set was originally produced by the Defense Mapping Agency. The files were obtained from NGDC and renamed from NGDC ETOPO5 (DBDB5 + topography). The .Z filename means the files were compressed with the Unix 'compress' command. These files are much smaller than the ASCII originals, but are now in binary form. Tell your FTP software to use a binary transfer, then uncompress the files on your system. On most Unix systems, type something like: uncompress etopo5.northern.bat.Z Each file is about 28 Mb in uncompressed ASCII. BACKGROUND The two data files on tape ETOPO5 are renamed files from the NGDC ETOPO5 (DBDB5 + topography) data as of 4/7/86. The files (NORTHERN.BAT and SOUTHERN.BAT) cover the northern and southern hemispheres and consist of integer bathy/elevation values in meters every 5 minutes of lat/long. The values are recorded starting at 90N 000E (for NORTHERN.BAT) or 00N 000E (for SOUTHERN.BAT), incrementing at 5 minutes of longitude eastward for 4320 values (360 degrees). The next logical record is 5 minutes south and contains 4320 values starting at 000E again. This pattern continues for 1080 logical records (90 degrees). Note -- 1 logical record (4320 values) = 4 physical records of 1080 values. For more information, contact: Norman Maher, US Geological Survey nmaher@octopus.wr.usgs.gov Fri Aug 13 13:36:54 PDT 1993