Shallow M6.7 aftershock hits off the coast of Honshu, Japan

The epicenter was located 115 km (72 miles) ENE of Hachinohe (population 239 050) and 116 km (72 miles) NE of Kuji (population 34 420), Iwate, Japan.

127 000 people are estimated to have felt moderate shaking and 2 785 000 light.

Based on all available data, there is no tsunami threat from this earthquake.

The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are resistant to earthquake shaking, though vulnerable structures exist. The predominant vulnerable building types are heavy wood frame and reinforced/confined masonry construction.

Recent earthquakes in this area have caused secondary hazards such as landslides and fires that might have contributed to losses.

This is an aftershock of the major M7.6 earthquake at 14:15 UTC on December 8, which prompted immediate tsunami warnings for Aomori, Iwate, and Hokkaido prefectures, with predicted wave heights up to 3 m (10 feet). Observed tsunami amplitudes, however, were much smaller: about 70 cm (2.3 feet) in Kuji (Iwate) and 50 cm (1.6 feet) at other coastal stations.

By the morning of December 9, official updates indicated at least 30–35 injured nationwide, mostly from falling objects or accidents during evacuation. Roughly 90 000 residents were ordered to evacuate as a precaution against a potential tsunami. All warnings were lifted by early morning, and most residents returned home after inspection of the infrastructure.

At 02:00 JST on December 9, the Japan Meteorological Agency issued a statement assessing the likelihood of a new large-scale earthquake in northern Japan as relatively higher than normal.

According to the agency, the December 8 earthquake occurred within a seismically active zone influencing the hypothetical source area of a megathrust earthquake along the Japan Trench and Kuril Trench system, which extends from offshore Nemuro in Hokkaido to offshore Sanriku in Tohoku.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

References:

¹ M6.7 earthquake Honshu, Japan – USGS – December 12, 2025

² M6.7 earthquake Honshu, Japan – EMSC – December 12, 2025