The Japan Meteorological Agency recorded a Magnitude 5.8 Earthquake at a depth of 20 km in the southeast of Fukushima Prefecture on Honshū Island, Japan, at 2.25 am Japan Standard Time on Friday 20 September 2013 (5.25 pm on Thursday 19 September, GMT). There are no reports of any damage or casualties arising from this quake, however it was felt across much of northern and eastern Honshū.
The approximate location of the 20 September 2013 Fukushima Earthquake. Google Maps.
Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. To the east of northern Honshū lies the Japan Trench, along which the Pacific Plate is being subducted beneath the Okhotsk Plate which underlies northern Japan, passing under the island as it sinks into the Earth. This is not a smooth process, the two plates continuously stuck together then broke apart as the pressure built up, causing Earthquakes in the process.
The epicenter of the Earthquake lies about 50 km to the southwest of the Fukushima I Nuclear Power Plant, which was destroyed by a tsunami following a Magnitude 9.0 Earthquake off the Japanese coast on 11 March 2013. The site has been leaking radioactive water into the sea since 7 August 2013, a leak which Japanese authorities are currently struggling to halt. While this quake does not appear to have made matters at the sight any worse, it does serve to emphasize that any long term solution to the site's problems must be able to cope with further Earthquakes.
See also Magnitude 6.9 Earthquake in the Izu Islands to the south of Japan, Japanese city covered in ash by eruption on Sakurajima Volcano, Eruptions on Sakurajima, Magnitude 6.0 Earthquake east of the Oshika Peninsula, Japan and Eruption on Suwanosejima.
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