Image processing applied to gravity and topography data covering the continental U.S.

A great deal of digital topographic information and gravity data exist that cover the continental United States. For instance, data sets that can be purchased from the National Oceanic and Atmospheric Administration (NOAA) include (a) elevations averaged over 30 s of latitude and longitude for the coterminus United States and (b) over a half million gravity readings from stations distributed across the entire country, although in an irregular manner. Both the topography and the gravity data sets are fundamental to the understanding of the structure of the crust and lithosphere, and especially to the understanding of the relationships between topography and structure [McGinnis et al., 1979; McNutt, 1981; and others].