The evolution of small canyons influenced by landslides: a case in LW area, north of the South China Sea
Presented by Dr. Xishuang LI on 23 Sep 2013 from 17:15 to 19:15
Type: Poster presentation
Session: Poster session
Dozens of small canyons arrange closely in the modern shelf break in LW area, north of South China Sea (SCS). These canyons have been formed and eroded since the middle Miocene. The significant terrain feature of these canyons are asymmetry cross-sections in which eastern flanks are steeper than the west. Multibeam bathymetry data and sub-bottom profiles revealed large quantities of small recent landslides in the canyon walls. Some larger landslides in the canyon head region were identified with multi-channel seismic data. The trigger mechanism of landslides in LW area is gravitational overloading, slope angle and properties of soil. Sliding direction of these landslides is perpendicular, parallel or oblique to the canyon axis. This indicates a complex process of mass transportation. We propose that the canyon was mainly excavated by turbidite current in the low sea level stage when the coast line advanced to the ocean and sediments supply in the upper slope was high. However, the canyon was mainly filled with mass sediments transported by landslides in the high sea level stage when the coast lines advanced to the land and sediments supplied to the upper slope reduced sharply.
Location: GEOMAR East shore
Address: Wischhofstr. 1-3 / D-24148 Kiel