UPDATE: The tsunami alert has been stood down by the Pacific Tsunami Warning Center. More to come..
A powerful earthquake with a preliminary magnitude of 7.2 has struck the Pacific Ocean near the Vanuatu Islands, seismologists say. There was no immediate word on damage or casualties but a tsunami alert has been issued. (more)
The earthquake, which struck at 8:23 GMT on Sunday, was centered about 81 kilometers (50 miles) northwest of Port-Olry a town in Sanma province on the island of Espiritu Santo, or 407 kilometers (253 miles) northwest of the capital Port-Vila. It struck about 35 kilometers (21.7 miles deep).
The Pacific Tsunami Warning Center, which put the earthquake's preliminary magnitude at 7.2, said a tsunami is possible and issued a tsunami threat message for Vanuatu. "Hazardous tsunami waves from this earthquake are possible within 300 km of the epicenter along the coasts of Vanuatu," it said.
It was not immediately clear whether a tsunami warning was in effect because the Pacific Tsunami Warning Center no longer issues formal warnings, and there was no immediate word from the Vanuatu Tsunami Warning Center.
The United States Geological Survey (USGS) estimated that some 186,000 people in the region may have felt the earthquake, including an estimated 18,000 people who may have experienced "strong" to "very strong" shaking. There was no immediate word about damage or casualties.
Vanuatu is on the so-called 'Pacific Ring of Fire', an arc of fault lines circling the Pacific Basin that is prone to frequent and large earthquakes. On average, the island nation and the surrounding waters are struck by about three powerful earthquakes every year. Volcanic eruptions also occur frequently in the region.
In August 2011, two powerful earthquakes measuring 7.1 and 7.4 on the Richter scale struck about 63 kilometers (39 miles) south-southwest of Port-Vila. Tsunami waves of up to 1.05 meter (3.4 feet) were observed on the island of Efate, but there were no reports of damage.