Measured and Estimated Seafloor Topography

IGPP, 0225
Scripps Institution of Oceanography
La Jolla, CA92093-0225
U.S.A.
phone: (619) 534-7109. FAX: (619) 534-9873

poster/oral: web page

D.T. Sandwell, Walter H.F. Smith, Stuart M. Smith, C. Small

We are constructing a complete bathymetric map of the oceans at a 3-10 km resolution by combining all of the abailable depth soundings collected over the past 30 years with high resolution marine gravity information provided by the Geosat, ERS-1/2, and Topex/Poseidon altimeters. Detailed bathymetry is essential for understanding physical oceanography and marine geophysics. Currents and tides are controlled by the overall shapes of the ocean basins as well as the smaller sharp ocean ridges and seamounts. Because erosion rates are low in the deep oceans, detailed bathymetry reveals the mantle convection patterns, the plate boundaries, the cooling/subsidence of the oceanic lithosphere, the oceanic plateaus, and the distribution of off-ridge volcanoes. Current global digital bethymetry maps (e.g. ETOPO-5) lack many important details such as a 400km-long ridge that rises to within 135 m of sea level. Moreover, they are contaminated by long-wavelength errors (~2000 km) which prevent accurate identification of seafloor swells associated with mantle plumes [Smith,1993].