RIVERSIDE--Experts are not surprised by the powerful undersea earthquake and tsunami near American Samoa.

The number of dead and missing is growing, but the toll is expected to fall far short of the 2004 Indonesia quake that sent a killer tsunami across the Indian Ocean.

Dr. Katherine Kendrick, a USGS geologist at UC Riverside, said both were caused by tectonic plates slipping beneath another.

“It’s a slightly different kind of mechanism, but still capable of generating tsunami waves.”

Those were estimated at 15-feet in the South Pacific. A tsunami 'advisory' was issued for the entire California coast, but no unusual waves were seen.

Dr. Kendrick says the improved Pacific tsunami warning system appears to have worked.

“Initially, there was a broad tsunami warning. But, when it was evaluated, it was narrowed.”

The epicenter of the South Pacific quake was 4,000 miles from Los Angeles. (INT)

Story Date: October 2, 2009