The Japan Meteorological Agency recorded a Magnitude 4.8 Earthquake at a depth of about 80 km, under Chiba Prefecture on Honshū Island, Japan, slightly before 0.55 am Japan Standard Time on Saturday 6 January 2018 (slightly before 3.55 pm on Friday 5 January GMT). There are no reports of any damage or casualties associated with this event, but many people have reported feeling the event across eastern Honshū Island.
The approximate location of the 6 January 2018 Chiba Prefecture Earthquake. USGS.
Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Eastern Honshū area lies on the boundary between the Pacific, Eurasian and Philippine Plates, where the Pacific Plate is passing beneath the Eurasian and Philippine Plates as it is subducted into the Earth. This is not a smooth process; the rocks of the two plates constantly stick together, only to break apart again as the pressure builds up, causing Earthquakes in the process.
Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
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