Image Name                   :  boug97cr
Boundaries                   :  Lat 7N to 30N ; Lon 272E to 304E
Color Scale, Upper (Red)     :  150 mgals and higher
Color Scale, Lower (Magenta) : -150 mgals and lower 
Data Max value               :  252.0 mgals
Data Min value               : -367.1 mgals
Illuminated from the         :  East 

  This is an image generated from 2'x2' terrain-corrected Bouguer gravity 
anomalies covering the Caribbean Sea and surrounding areas.  Some 
interesting features to note about this image are:

  The "sideways 'J'" magenta feature in the central and right side of the
image is the geoid signal induced by the extensions of the Puerto
Rico Trench (which exceeds 28,000 feet deep in some areas).  This 
trench marks an edge between the North American and Caribbean plates.
Near Puerto Rico, the N. American plate is sliding past the Caribbean
plate.  Further east, where the southward curving signal is noticed,
the N. American plate is subducting beneath the Caribbean plate.

  The high (yellow/orange) on the southeast side of Cuba is supported by
only a few data, but does represent a known high in the Bouguer anomaly
field.  This high is possibly due to an extension of the Cayman ridge
feature through the southeast edge of Cuba.

  The various channels, troughs and ridges, are easily located by their
impact on the geoid.  For example, one can see the Yucatan channel
running from the Gulf of Honduras, along the east coast of the Yucatan
Peninsula, and around the north side of Cuba.  Also the parallel
Cayman trough and Cayman ridge systems are seen running from the 
Gulf of Honduras to the south side of Cuba.

  The larger "bumps" seen in the oceans are the effect of seamounts on
the gravity field.

  Finally, some very fine lineations are seen in parts of this image.
These are ship tracks where measured gravity is offset slightly from
altimetric gravity anomalies.  

das/hjs 07/09/1997