A powerful 7.6-magnitude earthquake struck off northern Japan late Monday, triggering a tsunami of up to 20 inches in Pacific coast communities and warnings of potentially higher surges, the Japanese Meteorological Agency said.
The quake struck at about 11:15 p.m. local time (9:15 a.m. EST) in the Pacific Ocean about 50 miles off the coast of Aomori, the northernmost prefecture of Japan’s main Honshu island, the agency said.
A tsunami of 50 centimeters (about 20 inches) was measured in Kuji port in Iwate prefecture, just south of Aomori, and tsunami levels of 40 centimeters (about 16 inches) to 50 centimeters struck other coastal communities in the region, the agency said.
The agency issued an alert for potential tsunami surges of up to 10 feet in some areas, and Chief Cabinet Secretary Minoru Kihar urged residents to immediately head to higher ground or take shelter inside buildings or evacuation centers until the alert is lifted.
The quake struck northeast of the Aomori town of Hachinohe, and about 30 miles below the sea surface, the meteorological agency said. Hachinohe residents fled their homes to seek shelter in city hall, public broadcaster NHK said.
Several people were injured at a hotel in Hachinohe and a man in the town of Tohoku was slightly hurt when his car fell into a hole, NHK reported.
Kihara said nuclear power plants in the region were conducting safety checks and that so far no problems were detected.
The U.S. National Tsunami Warning Center said there was no tsunami danger for the U.S. West Coast, Canada’s British Columbia or Alaska.
Japanese Prime Minister Sanae Takaichi, in brief comments to reporters, said the government set up an emergency task force to urgently assess the extent of damage. “We are putting people’s lives first and doing everything we can,” she said.
The quake was also felt in the northern hub of Sapporo, where alarms rang on smartphones to alert residents.
A reporter for NHK in Hokkaido described a horizontal shaking of around 30 seconds that made him unable to keep standing as the earthquake struck.
Kyodo via Reuters 
Japan sits on top of four major tectonic plates along the western edge of the Pacific “Ring of Fire” and is one of the world’s most tectonically active countries.
The archipelago, home to around 125 million people, experiences around 1,500 jolts every year.
The vast majority are mild, although the damage they cause varies according to their location and depth below the Earth’s surface.
