First earthquake seafloor images back from SOC marine geologists in the Indian Ocean

Southampton Oceanography Centre marine geologists on board HMS Scott in the Indian Ocean earthquake zone have been sending back the first results of their seafloor survey.

Dr Tim Henstock and Dr Lisa McNeill were invited by the Royal Navy to join the survey ship HMS Scott during the offshore investigation of the earthquake zone. It is the first time that the seafloor has been observed so soon after an earthquake of this magnitude, which measured 9.0 on the Richter scale.

The earthquake occurred on Boxing Day 2004 some 40 kilometres below the seafloor where the Indian Plate is colliding with the Burman Plate. This collision has resulted in the Indian Plate being subducted (pushed underneath) the Burman Plate, and it was a sudden movement of these two plates that led to the devastating earthquake and tsunami.

The first results have yielded far more than the scientists had hoped for. Coloured contour maps of the seabed clearly show the boundary between the deep, flat Indian Plate, and the heavily deformed edge of the Burman Plate (boundary marked on images with a white dashed line).

These initial results will form the basis for further study in the area, as part of an international research effort. Dr Lisa McNeill said: "As a geologist I am really grateful for this opportunity to collect data across the earthquake zone. From this we hope to understand better the geological processes which produced the earthquake and ultimately help to determine future earthquake and tsunami hazards so that everyone can be aware and prepared."