Second undersea tremor hits Mindanao, S. Philippines

A magnitude 5.1 hit southern Philippines Thursday but there were no reported casualties and no tsunami alert either, the United States Geological Survey (USGS) reported in its website.

The undersea tremor, which occurred around 4:55 p.m. local time, had a depth of 623.1 kilometers. The epicenter was estimated at 110 km southwest of Cotabato city.

This is the second time Thursday that an undersea tremor occurred at the Moro Gulf.

The Philippines sits on the Pacific "Ring of Fire" where continental plates collide causing frequent seismic and volcanic activity. The worst earthquake in the country happened on August 16, 1976 after a tsunami killed between 5,000 and 8,000 people in the Moro Gulf region in southern Philippines.

Source: Xinhua