Magnitude 6.8 Quake Jolts Japan Off Fukushima, Tsunami Advisory Lifted

Source: Reuters

Magnitude 6.8 quake jolts Japan off Fukushima, tsunami advisory

TOKYO | Fri Aug 19, 2011 1:54am EDT

(Reuters) - A strong earthquake with a preliminary magnitude of 6.8 jolted northeastern Japan off Fukushima prefecture on Friday and a 50 cm tsunami advisory was issued for the coast of Miyagi and Fukushima prefectures, the Japan Meteorological Agency said.

The tsunami advisory was issued for the coastal areas that suffered severe damage from a massive quake and tsunami in March.

Tokyo Electric Power Co said no abnormalities had been found at radiation monitoring posts at the crippled Fukushima Daiichi nuclear power plant and that cooling operations at the damaged reactors were continuing.


Read more: http://www.reuters.com/article/2011/08/19/us-japan-quake-idUSTRE77I0S620110819

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The "Megaquake" of March 11 appears to have activated some of those faults.

It's normal in geologic-time scale, not so normal in human-time scale.

The room started shaking, but not violently. But it lasted a long time-- maybe 30-40 seconds (long for an earthquake). I knew from that it was a pretty big one, and figured it was from the Fukushima/Miyagi area, which was confirmed when I checked Yahoo Japan Weather. Fortunately, the most intensive seismic intensity on the mainland was a 5-, meaning that there may have been some minor damage.

By the way, there had been an earthquake earlier (last night) here in the Ibaraki area (70 miles south of the Fukushima border). Suddenly, there was a loud bang and jolt that was like someone had dropped a 10-ton weight on the street outside, and that was followed by a quivering motion that lasted about 15 seconds.

07:58 UTC : All the agencies have recalculated the earthquake by a seismologist and these are their updated results :
USGS : 6.2 @ 43.6 km
GFZ : 6.2 @ 52 km
EMSC : 6.3 @ 48 km
JMA : maintains their initial information at 6.8 @ a depth of 20 km (JMA is the official Japanese seismological agency)

only 2 injuries reported so far
http://earthquake-report.com/2011/very-strong-aftershock-out-of-the-honshu-coast-japan/