Imaging trench-line disruptions: Swath mapping of subduction zone

摘要

Analogous to other subduction zones in the world where the heavier oceanic plate shoves below the lighter continental plate, crustal movement along the Sumatra-Andaman trench line over the last two centuries released enormous stress causing earthquakes of highest impunity and generating, at times, devastating tsunamis. Such significant earth movements are presumed to have wide-ranging implications, stretching from geology to climate and to astronomy. A sea expedition within three months from the 2004 Sumatra-Andaman earthquake, and during the 2005 Sumatra earthquake is able to image the exact trench line, west of the Andaman Island. The multibeam bathymetry, gravity and fractal studies of about twenty-five thousand square kilometres off the west of Andaman Island have brought out several interesting features unknown earlier, including atypical disruption of the trench line.