Strong and shallow M6.6 earthquake hits Izu Islands, Japan

A strong and shallow earthquake registered by the JMA as M6.6 hit Izu Islands, Japan at 01:59 UTC on October 5, 2023. The agency is reporting a depth of 10 km (6.2 miles). The USGS is reporting M6.1 at a depth of 10 km (6.2 miles); EMSC M6.1 at a depth of 9 km (5.6 miles).

This is the second M6+ earthquake to hit the region since M6.3 at 11:38 UTC on October 3.

The epicenter was located 535 km (332.5 miles) S of Shimoda and 579.6 km (360.2 miles) SSE of Shizuoka, Japan.

There was no observation of seismic intensity 1 or above, JMA said. Tsunami warnings or advisories were temporarily in effect.

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.

Estimated population exposure to earthquake shaking

Regional seismicity

Featured image credit: TW/SAM, Google