Strong and shallow M6.1 earthquake hits near the coast of Hokkaido, Japan

A strong and shallow earthquake registered by the JMA as M6.1 hit near the coast of Hokkaido, Japan at 09:18 UTC on March 28, 2023. The agency is reporting a depth of 20 km (12.4 miles). The USGS is reporting M6.2 at a depth of 30 km (18 miles); EMSC M6.0 at a depth of 40 km (25 miles).

The epicenter was located 129.3 km (80.1 miles) ENE of Misawa (population 42 805), 131 km (81.2 miles) ENE of Hachinohe (population 239 046), and 133.6 km (82.8 miles) E of Mutsu (population 49 220), Japan.

1 078 000 people are estimated to have felt light shaking, according to the USGS PAGER.

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.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google