Japan Earthquake: After 7.5-Magnitude ‘MegaQuake’, Japan Lifts Tsunami Alerts; 30 Injured, 90,000 Evacuated

A powerful 7.5-magnitude earthquake off Japan’s northeastern coast late on Monday injured at least 30 people, triggered tsunami alerts and prompted evacuations of about 90,000 residents, before authorities lifted all warnings on Tuesday after limited sea surges and no major structural damage were confirmed across the affected region.

The quake, which struck at 11:15 p.m. (1415 GMT), led the Japan Meteorological Agency to warn that waves of up to 3 metres could strike parts of the northeast coast and to urge residents in several prefectures to move to higher ground as a precaution during the night.

Japan Earthquake: Tsunami Warnings, 'Megaquake’ Advisory Issued

Initial tsunami warnings covered Hokkaido, Aomori and Iwate, where ports later recorded waves between 20 and 70 cm, far below the maximum level feared, allowing the JMA to first downgrade the alerts to advisories in the early hours and then cancel all advisories once sea conditions stabilised and reports confirmed no serious coastal flooding.

Prime Minister Sanae Takaichi said authorities were still gathering information from local governments but added that, so far, reports pointed to relatively contained physical damage, though injuries and at least one fire were confirmed, with emergency services continuing checks of buildings and infrastructure in towns that experienced the strongest shaking across Aomori prefecture and nearby areas.

Japan Earthquake intensity and location

The epicentre lay about 80 km off Aomori prefecture at a depth of 54 km beneath the seabed, and on Japan’s seismic intensity scale of 1 to 7, tremors in Hachinohe city reached “upper 6”, a level that can make it hard to remain standing and may cause unsecured furniture or ceiling panels to fall inside homes and commercial buildings.

At a briefing, JMA officials underlined that the risk had not fully passed despite the lifting of tsunami advisories, stressing that strong aftershocks remain possible in the coming days and that residents in the broader region should keep emergency supplies ready and stay attentive to updated announcements as seismologists track continuing activity around the offshore fault zone.

“As of now, I have received reports of 30 people being injured and one fire,” Prime Minister Sanae Takaichi told reporters, while local media showed workers in Hachinohe clearing fallen items inside shopping and commercial centres on Tuesday morning after shelves collapsed and products scattered during the violent shaking overnight.

Japan Tsunami Risk After Major Earthquake

The JMA followed up the main tremor by issuing a wider advisory from Hokkaido down to Chiba prefecture, east of Tokyo, warning residents to stay alert for another powerful shock for a week, reflecting government practice introduced after 2011, when a magnitude 7-level earthquake struck two days before the catastrophic 9.0 event and deadly tsunami off Sendai.

“There is a possibility that further powerful and stronger earthquakes could occur over the next several days,” a JMA official said, noting that the advisory, described by officials as a “megaquake” alert, is designed to remind people to review evacuation routes, secure furniture and check communication plans with family members following any significant tremor in northeastern Japan.

East Japan Railway (9020.T) halted some services in the affected region after the quake as staff inspected tracks and overhead lines, while other train routes in northern Japan experienced delays; normal operations gradually resumed as checks confirmed no serious track distortion or signal malfunction, although commuters faced longer journeys during the morning rush.

No abnormalities were detected at nuclear power facilities run by Tohoku Electric Power (9506.T) and Hokkaido Electric Power (9509.T), according to the utilities, which reported that thousands of households initially lost electricity after the quake but that power had been restored by Tuesday morning, easing concern in an area that still remembers the Fukushima Daiichi nuclear accident in 2011.

Japan Earthquake Impact on Stock Market and Yen

The tremor briefly influenced financial markets, with the yen weakening against major currencies after the news broke and both the dollar and the euro touching session highs, although trading later stabilised as investors assessed early reports indicating limited damage and no disruption to core industrial or financial hubs.

2011 tsunami’s destruction of Fukushima Daiichi

Japan sits in the Pacific “Ring of Fire”, where several tectonic plates meet, and experiences at least one detectable tremor about every five minutes, accounting for around 20% of all global earthquakes of magnitude 6.0 or stronger; the March 11, 2011, disaster in the northeast still stands as Japan’s strongest recorded quake, with a 9.0 magnitude and tsunami that killed nearly 20,000 people and crippled Fukushima Daiichi.

Drawing from lessons learned in 2011, when a smaller quake preceded the main shock by two days, the government now automatically issues a one-week megaquake advisory after major tremors in the region, and officials said this latest alert would remain in force for the stated period even though tsunami warnings had ended and immediate disruptions were easing across the affected communities.

The 2011 tsunami’s destruction of Fukushima Daiichi, which triggered explosions and meltdowns in the worst nuclear incident for 25 years, continues to shape preparedness policies, and the government’s swift tsunami alerts, megaquake advisory and checks on nuclear and transport systems after Monday’s earthquake reflect efforts to limit casualties and disruption when strong quakes strike Japan’s densely populated northeastern coast.