April 9, 2009

Earthquake’s tsunami risk studied

U.S. geoscientists say the 2007 Solomon Islands earthquake might point to previously unknown increased earthquake and tsunami risks.

Professor Kevin Furlong of Pennsylvania State University and his colleagues studied the unusual tectonic plate geography and the sudden change in direction of the April 1, 2007, tsunami-generating earthquake. The magnitude 8.1 earthquake occurred east of Papua, New Guinea, off the coast of the Solomon Islands and its subsequent tsunami killed about 50 people, destroyed much property and was larger than expected.

This area has some of the fastest moving plates on Earth, said Furlong. It also has some of the youngest oceanic crust subducting anywhere.

Subduction occurs when one tectonic plate moves beneath another plate and in the Solomon Islands quake there were three plates involved, two of them subducting beneath the third while sliding past each other.

The researchers -- including Professors Thorne Lay of the University of California-Santa Cruz and Charles Ammon of Penn State -- said they were intrigued by the occurrence of a great earthquake where the three plates meet and investigated further.

They report their findings in the journal Science.