What is the slope of the U.S. continental slope?

Extensive high-resolution, multibeam bathymetry of five U.S. continental margins provides new, detailed information about the angle of continental slopes in different sedimentary and tectonic settings. The steepest continental slope examined is the passive-carbonate west Florida slope (4.4° regional slope and 12.0° mean local slope). The steepest of the four clastic continental slopes is the passive New Jersey-Maryland slope (2.5° and 7.6°). Less steep, at both regional and local scales, are the more rugged, technically active and probably unstable salt-tectonized Louisiana slope (0.5° and 2.9°), strike-slip California slope (1.8° and 5.2°) and convergent Oregon slope (2.0° and 5.2°). Frequency grids of local slope magnitude vs. depth and dip direction for the two passive continental slopes reflect present-day morphology predominantly being shaped by lithology (west Florida), sedimentation (New Jersey-Maryland), and downslope-directed erosion (New Jersey-Maryland, west Florida). The grids for the three technically active continental slopes reflect morphology partly (California) to predominantly (Louisiana, Oregon) being shaped by tectonics.

Duke Scholars

Author Lincoln F. Pratson Earth and Climate Sciences