News JMA warns of more temblors due to "slow slip"

[thomas]

The Japan Meteorological Agency has warned about increased seismic activity in Chiba Prefecture following a recent series of temblors. The agency has detected a "slow slip" phenomenon in the tectonic plates off the coast. Specifically, this slow-slip event is believed to be taking place off the Boso Peninsula, which lies on the boundary between the continental plate and the Philippine Sea plate. Anomalous movement in the Earth's crust was observed starting around Monday. Based on data collected up to Wednesday, approximately 2 centimetres of slippage has occurred along the plate boundary surface.

We had two stronger quakes Thursday night and Friday early morning.

Infographic by Kyodo​

Earthquakes occur when stress on a fault line or the area between tectonic plates builds up and ruptures. A rapid slide on the fault plane, which usually results in an earthquake, is the release of the strain seen over a period of seconds, whereas a slow slide constitutes movements that can continue for days or even years. According to the Japan Meteorological Agency, a relative increase in seismic activity has been observed from Monday off the east coast of Chiba Prefecture, including a magnitude-4.9 quake on Thursday and a M5.2 quake on Friday. Given past quake records in the area, the agency on Friday called on the public to be aware of "strong temblors," citing the possibility of a quake that could register lower 5 on Japan's seismic intensity scale of 7. Lower 5 is a situation where people may need to hold onto something stable, and items on shelves may fall off.

Japan agency warns of more quakes as temblors continue east of Tokyo

Japan's weather agency has warned of more earthquakes in Chiba Prefecture east of Tokyo following a series of temblors in recent days, detecting a movement known as "slow slip" in tectonic plates off the coast.

english.kyodonews.net

Japan warns of more strong quakes as ‘slow slip’ phenomena hits Chiba

Three earthquakes measuring a shindo 4 on the Japanese seismic intensity scale, as well as four measuring a shindo 3, have occurred since Thursday.

www.japantimes.co.jp