The first images of the seabed battered by the earthquake that triggered Asia’s catastrophic tsunami revealed huge ruptures spanning several miles.
A British naval ship collecting data off the coast of Indonesia’s Sumatra Island produced the digital images using sonar, and they could be used to help develop a tsunami early-warning system for the Indian Ocean region.
The vibrantly colored seabed maps shows that the 9.0-magnitude quake caused the tectonic plates to clash “like the rumpling up of a carpet,” according to Steve Malcolm, the commanding officer of the HMS Scott.
The images show “scars” more than six miles wide resulting from the Dec 26 quake. They depict the line where the Indian tectonic plate suddenly collided with, and was pushed underneath, the Burma plate. The maps, created with multibeam sonar, show ridges as tall as 4,950 feet that were created over thousands of years by the slow collision of the deep, flat Indian plate and the ragged edge of the Burma plate.
The collision has resulted in the Indian plate being gradually shoved under the edge of the Burma plate in a process known as subduction, said Russell Wynn, a marine geologist at the Southampton Oceanography Centre.
President Bush, meanwhile, said that he would ask Congress for $950 million for tsunami relief efforts – up from $350 million committed so far. The pledge would put the United States at the top of the list of donors for the disaster.