A satellite view of internal waves induced by the Indian Ocean tsunami

A satellite view of internal waves induced by the Indian Ocean tsunami D. A. SANTEK† and A. WINGUTH‡ †Cooperative Institute for Meteorological Satellite Studies, University of WisconsinMadison, Madison, Wisconsin, USA ‡Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA At 08:45 local time (02:45 GMT) on 26 December 2004, one hour and 45 minutes after the Sumatra Earthquakes of magnitude 9.3, a devastating tsunami struck the east coast of Sri Lanka. Nearly two hours and 30 minutes after the wave hit the coast, a weather satellite passed over Sri Lanka’s coastal zone providing a rare glimpse of internal waves along the continental slope due to this tsunami. The satellite imagery indicates wavelike features from the tsunami being reflected, diffracted, and scattered off the steep continental slope and submarine canyons adjacent to Sri Lanka. The energetic wave and its modification to internal waves possibly eroded sediment from the sea floor and transported it to the sea surface. Solitary features generated by internal waves can explain the observed pattern. Future modelling approaches considering these non-linear interactions would be required for a better understanding of the tsunami behaviour in the coastal zone, where its destructive effects are most prominent.