Single and multibeam echosounder surveys delineate Tsunami wave impacted depressions off Chellanum, Kerala

Detailed bathymetric surveys using the single beam echo-sounder (BATHY-1500) and Multi-beam echo-sounder (MBES-Seabat - 8111) along the nearshore sector off Chellanum coast of Kerala has brought out shore parallel depressions having depths of about 5 to 6m abruptly beyond the 4m level in the nearshore sector. The otherwise smooth and undulating shoreward gradient displays this abrupt anomalous depression as a recently developed feature. The Tsunami waves that lashed this part of the shore are seen to have caused extensive damage along the Chellanum coast. It is probable that the heavy impact of the tsunami wave in the nearshore could have scooped out the clayey sediments from the nearshore and caused these shore parallel depressions.