A strong magnitude-7.5 earthquake struck off the coast of Papua New Guinea on Saturday, according to the U.S. Geological Survey. The tremor hit at 1:04 GMT and was centered 75 kilometers, or 47 miles, southwest of the town of Panguna on Bouganville Island, a province of Papua New Guinea with a population of about 175,000 people.
The earthquake hit at a depth of 31 kilometers. Geoscience Australia said shaking was probably felt within a wide radius with localized damage possible.
According to the Associated Press, the Pacific Tsunami Warning Center issued a tsunami warning for Papua New Guinea and the Solomon Islands. However, officials weren’t sure if a tsunami had been generated, and the alert was later rescinded.
The USGS said there was a low likelihood of casualties and no injuries have been reported at this point.
Bougainville has been rocked by at least six strong tremors in the past week or so, Reuters reports, including a magnitude 7.3 earthquake on April 11. According to the USGS, since April 11, there have been 45 earthquakes of magnitude 4.5 or greater in the region, including a magnitude 6.6 tremor just 12 hours before Saturday’s 7.5 quake.
"Certainly it has been very active, more active than usual," Jonathan Bathgate, a seismologist at Geoscience Australia, told Reuters. "[The spate of earthquakes] is relieving some pressure on this faultline, but we can't rule out another large earthquake."
Papua New Guinea is a hotspot for seismic activity, given its location on the so-called Pacific Ring of Fire, a horseshoe-shaped series of oceanic trenches and plate movements that stretches from the tip of South America over to Southeast Asia. About 90 percent of the world’s earthquakes occur along this ring. The Pacific Island nation sits on the Australia-Pacific plate boundary which stretches 4,000 kilometers from the Sunda trench, also called the Java trench, in the west to the Solomon Islands in the east.
Since 1900, the New Guinea region has experienced 22 magnitude-7.5 or greater earthquakes.
It wasn’t initially clear whether Saturday’s tremor, whose epicenter was located near a sparsely populated area of Bouganville Island, had caused any significant damage.
"Because it's such a large event there's a possibility of damage in that area," seismologist Emma Mathews told AFP. "But it's nothing out of the ordinary for such an earthquake-prone country."