The waters off of Indonesia were rocked by a 7.6-magnitude earthquake at 4:43 a.m. local time Sunday, the US Geological Survey reports. The quake's epicenter was about 150 km (95 miles) off the coast of Manokwari, in the West Papua province, and 170 km (105 miles) from the city of Sorong. It was followed by at least two aftershocks, one measuring 7.5 on the Richter scale.
There were no immediate reports of injuries or damage, although the BBC quoted a police officer in Manokwari saying that power outages made assessing the area difficult.
The strength of the earthquake prompted authorities to issue a tsunami warning for the area, which was hit by an 8.2-magnitude earthquake on February 17, 1996. That quake, and an associated tsunami, killed more than 100 people, according to the USGS. The tsunami warning today was withdrawn within an hour.
The region is the site of several continental plates, in the words of the USGS, "by complex tectonics in which motions of numerous small plates are accommodating large-scale convergence between the Australia, Pacific, and Eurasia plates." The 2004 tsunami that killed about 230,000 people was the result of an earthquake in western Indonesia.
For more on temblors, including what makes them stop, and some surprising places you might experience them, see our guide to earthquakes.
Map of seismic activity, courtesy USGS