Morphologic signatures in submarine canyons and gullies, central USA Atlantic continental margins

The accumulation of bathymetric and seismic data on many continental margins has provided valuable new insights into variability of seascape morphology. The present challenge is in finding appropriate manners to characterise that morphology so that variations between areas and between potential influences can be recorded. In this paper, we employ hypsometty (area-elevation analysis) and present parameters derived from 65 hypsometric curves which represent distinct slope-basin shapes, based on data from the central USA Atlantic continental slope. The distinction of morphologic signatures has derived from the statistical moments, such as skewness and kurtosis, in describing the hypsornetric curves of the submarine basins. Moreover, basin geometry in planview and network structure, have shown to be remarkably well reflected in the shape of the hypsometric curve. Based on the combined analysis of morphology and submarine processes and scenarios, we propose that concave hypsometry is characteristic of trellis networks that probably initiated by sporadic erosion by sedimentary flows, spilling over the shelf edge. The convex hypsometry that characterises poor- to well- developed dendritic networks, heading at or below the shelf break, is attributed to retrograde erosion and sediment fallout events, respectively. These results present initial step in helping to infer submarine processes from morphology, and provide initial information about the environmental scenarios for areas where the erosional record is unknown. (C) 2012 Elsevier Ltd. All rights reserved.