Japan earthquake tonight: magnitude 7.5–7.6 off the northeast coast triggers tsunami warnings, late-night evacuations, and rail suspensions

A powerful earthquake struck off northern Japan late Monday night, shaking Hokkaido and the Tōhoku coastline, prompting immediate tsunami warnings and large-scale coastal evacuations. Initial estimates placed the magnitude between 7.5 and 7.6 with an offshore epicenter east of the Aomori–Hokkaido corridor at a depth of roughly 50–60 km. The shaking reached upper 6 on Japan’s 1–7 intensity scale in parts of Aomori—strong enough to topple furniture and damage non-reinforced structures.

Tsunami status and coastal impacts

The national meteorological agency issued tsunami warnings up to 3 meters for stretches of Hokkaido, Aomori, and Iwate shortly after the quake, activating coastal sirens and text alerts. Observed waves were generally below one meter—on the order of 20–70 cm at early gauges—leading to a downgrade from warnings to advisories as the night progressed. Authorities still urged people to stay clear of beaches, river mouths, and harbor walls until all advisories are lifted, noting that dangerous currents and secondary surges can follow smaller initial waves.

Damage snapshot and disruptions

Early reports cited injuries in the single digits and no immediate signs of major structural damage in population centers closest to the shaking. Rail services across portions of Hokkaido and northern Tōhoku were temporarily suspended for track inspections, with late trains canceled or significantly delayed. Utilities recorded brief power outages affecting thousands immediately after the quake; service was restored to most customers overnight, with isolated pockets still being addressed. Operators reported no abnormalities at nuclear power facilities after automatic checks.

Where the quake was felt

• Strong to very strong shaking: coastal Aomori (including Hachinohe area) and southern Hokkaido.

• Moderate shaking: Iwate and Akita prefectures along the Pacific side.

• Light shaking: inland Tōhoku and parts of eastern Hokkaido.

Given the offshore depth and location along the boundary where the Pacific Plate dives beneath northern Honshu and Hokkaido, shaking was broadly distributed, with longer, rolling motion reported in high-rises and newer towers designed to sway.

Aftershocks: what to expect

Seismologists warned that strong aftershocks (M6-class) are possible in the coming days, with numerous smaller events likely through the week. The probability of a significant follow-on shock is highest within 24–72 hours of the main event. Coastal communities should anticipate intermittent advisory updates, as aftershocks can trigger additional small tsunami waves or hazardous currents even if no major sea-level rise is observed.

Guidance for residents tonight and Tuesday

1. Stay away from the water until all tsunami advisories are canceled; avoid breakwaters and river mouths where currents can be strongest.

2. Expect late service changes on trains and ferries; confirm morning schedules as operators finish overnight safety checks.

3. Check for hazards at home: gas smells, fallen heaters, cracked chimneys, and unsecured furniture. If gas is suspected, shut off the valve if safe and call from outside.

4. Prepare for aftershocks: keep a flashlight, shoes, and a charged phone within reach; sleep away from tall shelves or unsecured TVs.

5. Use official alerts: rely on municipal apps, TV/radio, and cell broadcast messages for evacuation, shelter, or “all clear” notices.

Why the tsunami risk was limited this time

Large tsunamis arise when quakes significantly deform the seafloor. Monday’s event, while strong, occurred at an intermediate depth for the region and likely produced modest vertical displacement, consistent with the sub-meter waves recorded at coastal gauges. Even so, modest waves can create chaotic harbor conditions and strong in-harbor currents, which is why shoreline access remains restricted until authorities lift advisories.

What to watch in the next 48 hours

• Revised magnitude and depth as additional stations refine the solution overnight.

• Aftershock pattern: whether activity tracks along the plate interface toward Hokkaido or back toward the Sanriku offshore.

• Infrastructure updates: bridge and embankment inspections on coastal highways; any reports of minor landslides on steep or snow-covered slopes.

• Community needs: warming shelters and temporary accommodations for evacuees who left coastal lowlands during the initial warning window.

A very strong offshore earthquake jolted northern Japan late Monday, triggered short-lived tsunami warnings, and led to precautionary evacuations and transport delays. With observed waves staying mostly under a meter and power restored to most areas, the immediate crisis eased overnight—but aftershocks and lingering marine hazards keep vigilance high into Tuesday.