Shallow M5.6 earthquake hits offshore Honshu, Japan on August 26, 2026 (Updated)

A shallow M5.6 earthquake was recorded at 19:21 UTC on August 26, 2026, about 209 km (130 miles) east-southeast of Ōfunato, Japan. The event originated offshore at a depth of 16.1 km (10 miles), according to data released by the USGS.

The earthquake’s coordinates were 38.2°N, 143.8°E, placing it in the Pacific Ocean off the eastern coast of Honshu, near the Sanriku coast region of Japan. This offshore area is known for its tectonic activity, lying close to the boundary between the Pacific Plate and the Okhotsk Plate.

Critical infrastructure in the region typically includes major seaports, undersea communication cables, and international shipping lanes traversing the northwestern Pacific Ocean. No onshore population centers were immediately adjacent to the epicenter due to its offshore location, though the nearest coastal communities include Ōfunato and Kamaishi.

There is no tsunami threat associated with this earthquake, based on its offshore location and available data.

USGS issued a green alert for this event, indicating a low likelihood of casualties or damage. The maximum estimated intensity was III, with one felt report submitted. The significance index is 483 (on a scale that runs through 1 000), based on magnitude, felt reports, and estimated impact.

Japan is part of the seismically active Pacific Ring of Fire, where the Pacific Plate subducts beneath other tectonic plates, resulting in frequent offshore and coastal earthquakes, including major historic events in this region.

This information was last updated at 16:21 UTC on August 27, 2026.