Strong M6.1 earthquake hits near Tokyo, Japan
Image credit: TW/SAM, Google
A strong earthquake registered by the JMA as M6.1 hit near Tokyo, Japan at 13:41 UTC (22:41 LT) on October 7, 2021, at a depth of 80 km (50 miles). The USGS is reporting M5.9 at a depth of 62 km (38 miles), EMSC M5.9 at 80 km (50 miles).
The epicenter was located 3.7 km (2.3 miles) SSW of Chiba (population 919 729), 6 km (3.7 miles) NNE of Ichihara (population 283 531) and 18.4 km (11.4 miles) SE of Honcho (population 560 743), Chiba, Japan.
There are about 38 000 000 people living within 100 km (62 miles).
2 774 000 people are estimated to have felt strong shaking, 26 981 000 moderate, and 16 485 000 light, according to the USGS PAGER.
The quake registered an intensity of 5+ on Japan's seismic scale of zero to seven in Tokyo's Adachi Ward, as well as Kawaguchi City and Miyashiro Town.
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.
Authorities said there have been no reports of major damage.
The earthquake disrupted public transport throughout the Metropolitan area, NHK reports.
One train in Tokyo's Adachi Ward derailed after making an emergency stop, injuring at least three people, NHK reported.
The tremor ruptured water pipes in several neighborhoods.
Emergency crews rushed to a fire that broke out in a building outside the capital, and the wall of a building in northern Tokyo collapsed.
JMA warns that more earthquakes of similar intensity are possible over the next week or so.
The officials say an intensity of 5+ was recorded in Tokyo's 23 wards and Saitama for the first time since the M9 earthquake in March 2011.
Estimated population exposure to earthquake shaking
Selected cities exposed
Regional seismicity
Teo Blašković founded The Watchers in 2011 and edited it until 2026, covering seismic and volcanic activity, extreme weather, space weather and near-Earth objects. Articles on this page are his archive.
Earlier reporting
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