A strong earthquake was recorded off the coast of Japan’s Fukushima Prefecture on Thursday morning local time.
The US Geological Survey said the quake, which was measured at 5.5-magnitude, took place about 40 to 50 miles from Fukushima Prefecture, which was hard-hit during the 2011 quake.
It’s unclear if there was any damage or injuries.
The quake had a depth of 6.2 miles, said the USGS.
AP update on quakes: Scientists try to decipher Idaho earthquake swarms
BOISE, Idaho (AP) — The latest earthquake swarm in central Idaho could help scientists better understand quake belts extending from Yellowstone National Park.
The most recent swarm in the Challis area started this week and so far 20 quakes have been recorded, the largest a magnitude 3.7 on Monday.
“There’s obviously a fault down there at depth to produce these, and the town of Challis happens to be built on top of it,” said scientist Mike Stickney of the Montana Bureau of Mines and Geology based in Butte, Montana. “We have no indication that it’s leading to a larger event.”
The quakes are occurring at the northern tip of the Lost River Fault but it’s not clear if that fault is involved or if an unknown fault is at work. The Lost River Fault caused Idaho’s largest recorded quake, a magnitude 6.9, rumbling in 1983 near 12,667-foot Borah Peak, Idaho’s tallest peak.
Scientists brought in portable seismographs to monitor an earthquake swarm last summer. Most were removed after the swarm stopped but one was left in place.
It “completely stopped and then just a couple days ago it started up again,” said Melanie Corrigan, a dispatcher with the Custer County Sheriff’s Office. “People are just like, ‘Oh, great, here we go again.'”
She said no damage has been reported.
Stickney said the quakes are being produced by different triggers, indicating a complex process that’s poorly understood. The swarms are occurring within the Centennial Tectonic Belt extending west from Yellowstone National Park. The Intermountain Seismic Belt extends north and south from Yellowstone through multiple states.