Morphotectonic and morphometric analysis of the Nazca plate and the adjacent offshore Peruvian continental slope - implications for submarine landscape evolution

摘要: We use new swath bathymetry data acquired during the RV Sonne cruise GEOPECO and complement them with from adjacent regions to analyse morphotectonics of Peruvian convergent margin. The Nazca plate is not covered sediments therefore has a rough surface along entire trench. styles roughness differ significantly margin linear morphological features trending in various directions, most oblique trench magnitudes few several hundred meters. lower slope locally very at verge failure throughout margin, as result subduction erosion causing over-steepen. Using curvature attributes quantitatively examine morphology Yaquina Mendana areas revealed that latter shows larger local both seaward landward However, amplitude area. identified 125 km2 large slump on Lima middle slope. Morphometric dating suggests an age 74500 years within 35 40% error. Estimated incision rates upper are between 0.1 0.3 mm per year suggesting landscape evolution submarine continental similarly slow than Atacama desert.