ETOPO5 Data Set
---------------

etopo5.northern.bat.gz   7.5 Mb
etopo5.southern.bat.gz   7.0 Mb

        (etopo5.northern.bat.Z   8.3 Mb)
        (etopo5.southern.bat.Z   7.9 Mb)

        (etopo5.northern.bat    28.0 Mb)
        (etopo5.southern.bat    28.0 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 .gz filename means the files were compressed with the GNU 'gzip' 
utility.  Gzip performs better compression than 'compress' and is
therefore used here.  To uncompress type :

    gzip -d  etopo5.northern.bat.gz
    gzip -d  etopo5.southern.bat.gz

OTHER FORMAT
------------

The file etopo5.nc is the same as etopo5.northern.bat and etopo5.southern.bat
together except that it is written using the netCDF 2.3 library.

If you know how to handle this format, download it instead of the 2 other.
If you don't know it, don't take it !


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).

!!! Please note that the elevation at 90S (south pole) is not given !!!

Note --
1 logical record (4320 values) = 4 physical records of 1080 values.
Use FORTRAN format '1080I6' to read the records.

Fri Aug 13 13:36:54 PDT 1993
------------------------------------------------------
Comments added Mon Jan 30 by roland@modb.oce.ulg.ac.be

Be carefull with the ETOPO5 data set.  There seems to be several errors in it,
especially a westward shift of the data (???).  We would appreciate your
comments on this data set.