USGS: 7.8 Quake Hits Sumatra, Tsunami Watch Lifted

BY kgardiner  April 6, 2010 at 8:20 PM EDT

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A 7.8-magnitude earthquake struck early Wednesday morning local time near Sumatra, Indonesia, according to the U.S. Geological Survey. The quake triggered a tsunami warning in the region, but the Indonesian government lifted it within several hours.

Officials reported no immediate major damage or casualties.

Susan Potter, a USGS geophysicist, told The Rundown that the quake happened in a particularly active tectonic area, about 325 miles west of Kuala Lumpur, Malaysia, and about 880 miles northwest of Jakarta. Hear our full conversation:

“What you have is one tectonic plate diving beneath another,” she said. “When this occurs, you have earthquakes in the plate that’s subducting, and in the plate above.”

Potter said the quake is one of several rated higher than 7.0 so far this year. She said the USGS expects about 17 similar-sized quakes worldwide every year.