Image Name                   :  egm96crn
Boundaries                   :  Lat 9N to 28N ; Lon 274E to 302E
Color Scale, Upper (Red)     : +15.8 meters and higher
Color Scale, Lower (Magenta) : -70.7 meters and lower 
Data Max value               : +15.8 meters
Data Min value               : -70.7 meters
Illuminated from the         :  East 


  This is an image generated from 2'x2' geoid undulations covering the
Caribbean Sea and surrounding areas.  These undulations were
generated from the EGM96 spherical harmonic model of the Earth's external
gravitational potential.  Some interesting features to note about this image are:

  Unlike the CARIB97/DCAR97 models, the resolution of the EGM96
grid is 30'.  Thus, even though the values are gridded at 2' spacings, 
features smaller than 30' wide are not resolved in the model.  Many of 
the features in this image can been seen in the CARIB97 image, but with
somewhat less detail here.

  The geoid high, is an elongated red spot running through Central America
into Panama.  This coincides with the rise in bathymetry from the floor of
the Caribbean Sea up to the continental land masses. 

  The magenta/purple low, curving around the right side of the image, is the
effect of the Puerto Rico Trench on the geoid.  The abyssal drop of the trench
to over -28,000 feet, induces a change of -30 meters in the geoid over 100 km
(a 300 ppm tilt). 
  
  The small high in Colombia is in an area of no gravity measurements.  However, the
EGM96 field shows this high, and it corresponds well with the Sierra Nevada de
Sta. Marta Mountains (with peaks over 18,000 feet).

das/dgm 10/18/96