Magnitude 6.1 Earthquake Strikes Offshore Japan, 144 km Southeast of Hasaki

A strong earthquake struck off Japan's Pacific coast on Friday evening local time. The U.S. Geological Survey put the quake at magnitude 6.1, striking at 10:39 UTC on November 6, 2026 — 7:39 p.m. in Japan — with its epicentre 144 km (89 miles) southeast of Hasaki, in Chiba Prefecture, at a depth of 29 km (18 miles). The USGS has reviewed the event, catalogued as us7000twg9.

It was the second magnitude 6.1 earthquake of the day worldwide, and the first magnitude 6 or larger quake in three days — a reminder that a quiet stretch on the global catalog can end without warning.

The USGS located the epicentre at 34.968 degrees north, 142.118 degrees east — well offshore in the Pacific, east of Chiba Prefecture and roughly 237 km from Tokyo. The agency recorded the magnitude as 6.1 on the moment magnitude scale (Mww), from 134 stations.

Depth figures differ slightly between agencies, as they often do in the first hours: the USGS puts the depth at 29 km, while the Japan Meteorological Agency's figure, as reported, is about 10 km. Either way it was a shallow offshore event, far enough from the coast that shaking on land was moderate rather than severe.

No. The Japan Meteorological Agency issued no tsunami alert for the quake, and the USGS record for the event carries no tsunami flag. The quake was centred far offshore, and neither agency treated it as a tsunami source.

That distinction matters for offshore Japan quakes: magnitude alone does not make a tsunami — the quake has to move the seafloor vertically, and forecasters check that within minutes. In this case, both the national agency and the USGS stood down the tsunami question almost immediately.

No damage had been reported in the coverage reviewed on Friday. The USGS PAGER system issued a green alert for the event, meaning little or no damage is expected — the system's lowest alert level.

People did feel it. The USGS received 27 felt reports for the event, with a maximum community-reported intensity (CDI) of 4.2 — shaking strong enough to rattle dishes and wake sleepers near the coast, well short of damaging levels. Instrumental estimates put moderate shaking (MMI V) around Hasaki and light shaking (MMI IV) in Tokyo.

No — it was one of two magnitude 6.1 events inside 24 hours. The other struck the Fiji region at 17:21 UTC on November 5, but at 535 km (332 miles) deep it was far too deep to cause strong shaking at the surface, and it too drew a green rating. In total, the USGS catalog recorded 11 earthquakes of magnitude 4.5 or more and 184 of all sizes worldwide in the 24 hours to 12:22 UTC on November 6 — and no magnitude 6 or larger quake had struck in the three days before that window.

Two same-magnitude quakes in one day, one shallow and one extremely deep, are a neat illustration of why depth matters as much as magnitude: Friday's Japan event, at 29 km, was felt in a capital city; Thursday's Fiji event, at 535 km, passed almost unnoticed at the surface.

WorldEye's earthquake tracker plots the USGS feed as events are reviewed and posted, so a quake like Friday's appears on the globe alongside the day's smaller seismicity — and the aftershocks, if any follow, will show up in the same view.

USGS magnitudes and depths can be revised as more station data arrives; the figures in this story are the reviewed values as of Friday morning, U.S. time. For official information in Japan, the Japan Meteorological Agency remains the authority.