Japan warns of slightly increased risk of mega-quake after a 7.7-magnitude one

An official of the Japan Meteorological Agency speaks near a monitor showing a tsunami alert during a news conference at the agency in Tokyo, Monday, April 20, 2026, after an earthquake that struck off the northern Japanese coast. (Masanori Kumagai/Kyodo News via AP) 2026-04-20T08:19:59Z Tokyo (AP) — An earthquake registering a preliminary magnitude of 7.7 off northern Japan on Monday prompted a short-lived tsunami alert and the advisory of a higher risk of a possible mega-quake for coastal areas there. The Cabinet Office and the Japan Meteorological Agency said there was a 1% chance for a mega-quake, compared to a 0.1% chance during normal times, in the next week or so following the powerful quake near the Japan-trenches" class="entity-link entity-location" data-entity-id="119762" data-entity-type="location">Chishima and Japan trenches. Officials said the advisory was not a quake prediction but urged residents in 182 towns along the northeastern coasts to raise their preparedness while continuing their daily lives. Prime Minister Sanae Takaichi, speaking to reporters, urged residents in the affected area to confirm their designated shelters and evacuation routes and to check emergency food and grab bags so they can run immediately when the next big one hits. “The government will do our utmost in case of an emergency,” she said. It was the second such advisory for the region in recent months. One was issued following a 7.5-magnitude quake in December but no mega-quake occurred. The Fire and Disaster Management Agency said one person in Aomori, north of Iwate, was injured after falling Monday. Still, Monday’s earthquake and tsunami warning were a reminder to the quake-prone area of the March 2011 disaster that ravaged large swaths of the northern coast, triggering a nuclear crisis in Fukushima. (