A magnitude 5.8 earthquake struck off of North Korea in the Sea of Japan on Thursday, but was not likely to cause damage, according to the U.S. Geological Survey (USGS).
A quake of that size is unusual for that area but not unprecedented, USGS seismologist Julie Dutton told Reuters. She said the last large quake in that part of the Sea of Japan was back in 1994.
North Korea causes seismic events when it conducts underground nuclear bomb tests, but there was nothing to indicate this quake was a man-made event. Additionally, all of North Korea’s underground nuclear tests have been conducted on land.
A Pentagon spokesman said initial indications showed that the quake did not result from a nuclear test.
The quake, which struck early in the morning on Thursday, was very deep, 334.1 miles (or 538 km) below the seabed. Its epicenter was 112 miles (or 180 km) southeast of the North Korean city of Chongjin.
Initially, it was reported as a magnitude 6.0 but was later revised to 5.8.