Officials have canceled a tsunami watch in the Indian Ocean region, hours after an 8.6-magnitude earthquake struck off the northwestern coast of Indonesia.
The quake hit Wednesday about 430 kilometers southwest of Banda Aceh, the provincial capital and largest city in the province of Aceh, at an estimated depth of 22 kilometers. An 8.2-magnitude aftershock was reported by the U.S. Geological Survey about two hours after the initial earthquake.
The U.S. Pacific Tsunami Warning Center originally issued a tsunami watch for several countries in the region after the quake. But it says local authorities can now assume the threat has passed since sea level readings indicate the danger has diminished or is over for most areas.
A seismology expert said the earthquake's movement was horizontal rather than vertical, creating less risk of a large displacement of water needed to trigger a tsunami.
People on motorcycles rush to higher ground after earthquake in Aceh, Indonesia, April 11, 2012. (VOA Photo - Budi Nahaba)
Indonesian President Susilo Bambang Yudhoyono said the situation is "under control" in Aceh and there is no immediate threat from a tsunami.
No casualties have been reported so far from the quake, which sent citizens in Aceh scurrying out of buildings and into the crowded streets.
Aceh was the worst-effected area by the December 2004 Indian Ocean tsunami that was triggered by a 9.1-magnitude quake. That tsunami killed an estimated 230,000 people, about half of them in Aceh province.
Preacher Salman Iqbal leads post-earthquake prayer in Ulee Kareng, Banda Aceh, April 11, 2012. (VOA Photo - Budi Nahaba)
Sutopo Nugroho from Indonesia's National Disaster Agency says the country's warning system has improved since then. “The early warning system in Aceh and Padang and west of coast of Sumatra is already well done, and we have already give(n) instruction to mosques and church(es) to give information to the people," he said.
Video footage from Indonesia
Wednesday's quake was at approximately the same depth as the 2004 Indian Ocean quake. It reportedly rattled buildings as far away as Singapore, Thailand, and India. Officials issued coastal evacuation orders throughout the region, and authorities scrambled to evacuate beaches.
Somchai, the general manager of the Centara Beach Resort on Karon Beach in Phuket, Thailand, told VOA that while government sirens came late, his resort was prepared.
"We directly called the guests to the room. For all of them. And we put the warning alarm so they can hear everywhere in the hotel. And now our guests, most of them, [have] come up to the meeting point," Somchai said.
If early projections do not change, Wednesday's quake would be tied for the ninth largest since 1900.
The massive quake that devastated coastal northeastern Japan last year was a magnitude 9.0 and killed around 19,000 people.