Role of bathymetry in tsunami amplification - evidences from Andhra Pradesh coast

摘要

Interpretation of satellite images representing both the pre- and post-tsunami of 26 December 2004 revealed three isolated locations along the Andhra Pradesh coast where the tsunami amplified despite its overall diminishing strength northward from Tamil Nadu. The digital elevation models generated from the depth contours traced from the National Hydrographic Charts indicated landward convexities in the 5 m depth contour juxtaposing the three locations. Apparently, the tsunami amplified locally as itentered these narrow canyon-like zones and threw up sediment onto casuarina plantations, aquaculture ponds, saltpans and other land-use features. The study highlights the possible role of nearshore bathymetry in tsunami amplification.