Japan’s Environment Ministry announced that due to the March 11th Tohoku earthquake more than 6,000 square kilometers of land across Japan settled by more than 2 centimeters in the last year, the largest-ever since records began in 1978.
Experts and officials are worried about the potential impact on building stability. About half the 30 tested areas in 20 prefectures were recorded as sinking more than 2 centimeters. Seven areas subsided by more than 10 centimeters, and are spread out around the Tohoku and Kanto region, including Tokyo.
Kesennuma in Miyagi Prefecture sank deepest by 73.8 centimeters, followed by Ichikawa in Chiba by 30.9 centimeters. Tsukuba in Ibaraki sank by 15.2 centimeters.
Immediate Subsidence caused by 2001 Tohoku Earthquake
The Geospatial Information Authority of Japan reported immediate subsidence caused by the 2011 Tōhoku earthquake.
In Northern Japan, subsidence of 0.50 m (1.64 ft) was observed on the coast of the Pacific Ocean in Miyako, Tōhoku, while Rikuzentakata, Iwate measured 0.84 m (2.75 ft).
In the south at Sōma, Fukushima, 0.29 m (0.95 ft) was observed. The maximum amount of subsidence was 1.2 m (3.93 ft), coupled with horizontal diastrophism of up to 5.3 m (17.3 ft) on the Oshika Peninsula in Miyagi Prefecture.