Sonograph mosaics of submarine slope instabilities, Mississippi River Delta

Abstract

Sonograph mosaics of submarine slope instabilities have been compiled from new sonographs that were acquired from an area of the Mississippi delta-front slope in water depths of 10–50 m. The sonographs are free from scale distortions, and tonal and textural patterns indicate considerable topographic variety, including subparallel scarps, blocky areas enclosed by scarps, elongate sinuous channels, depositional lobes, and collapse depressions. These are interpreted as the results of various types of subaqueous mass movement. Adjacent scale-true survey lines have been combined, using accurate navigation, yielding the first-ever composite sonograph mosaics of submarine slope instabilities. The mosaics represent both internal feature detail and spatial associations.