Published: Aug 18, 2010 10:22 PM EDT
Updated: Aug 18, 2010 7:22 PM EDT

LOS ANGELES (AP) - New research reveals that a deadly tsunami that pounded several South Pacific islands last year was spawned by not one but two monstrous earthquakes. Initially, it was thoughtthat a single powerful magnitude-8.1 jolt triggered the tsunami last September. Nearly 200 died in Samoa, American Samoa and Tonga. Scientists now conclude that the disaster was the result of a rare double whammy - two strong earthquakes that hit within minutes of each other.