A global mapping program of those geologic parameters that may influence acoustic propagation through the ocean floor has evolved a number of mappable parameters including bathymetry, physiographic provinces, surface sediments, sediment thickness, paleomagnetic anomalies and age of seafloor, inferred thickness of lithosphere, heat flow, potential temperature of deepest waters, areas of possible bottom current activity, acoustic velocity of deepest waters, acoustic velocity in uppermost sediments, calculated ratios of acoustic velocity along water-sediments interfaces, possible petrologic provinces within lithosphere, roughness of acoustic basement, regional structure, and earthquake locations.

Mapping efforts present maximum detail consistent with data and application of established geologic principles. In areas lacking sufficiently definitive data, a reasonable interpretive fabric is shown. By interrelating appropriate parameters, greater interpretive accuracy is routinely possible.

The principal correlations between parameters are

End_Page 741------------------------------

those that fall within the province of plate tectonic theory. Relations between several of these parameters are obvious, e.g., bathymetry and physiographic provinces, and paleomagnetic anomalies and seafloor age. New generations of model reliabilities will occur as further interrelations are found.

The current suite of theories describing overall geologic phenomena, e.g., seafloor spreading and marine sedimentation, are adequate in first order, basinwide terms. Second and third order accuracies are not possible without interpretation on a regional scale.

End_of_Article - Last_Page 742------------