A massive earthquake of magnitude of 9.0 occurred Friday 11 March, off the Pacific coast of the northeastern part of the Japanese main land (Tohoku Region), causing devastating damages. The Japan Meteorological Agency named this earthquake the 2011 Great East Japan Earthquake.
||Magnitude 7.6 at 11 March 2011 15:15 JST (06:15 UTC)
||(magnitude 7 or greater)
||(magnitude 6 or greater)
||(magnitude 5 or greater)
More Info on Aftershock / Aftershock Outlook
After the earthquake on 11 March, many weather observation data from AMeDAS (JMA's automated weather observation and collection system) stations in Northern Japan had been suspended due to tsunami damage, network failure, and power outage. As of 15 April, JMA has resumed most of its AMeDAS stations. You can see the related story on recovery of weather observation systems.
In addition, NTT docomo (a mobile telecommunication company in Japan) has provided JMA with meteorological observation data at its 5 environmental monitoring stations (verified and notified in advance) near the tsunami affected areas in Tohoku District, based on the Meteorological Service Law.
Seismometers, seismic intensity stations, and tidal gauges are also recovered as follows.
||Number of troubled facilities
||Total number of facilities
|11 March 2011
||16 May 2012
||(Tohoku District) 26
|Seismic Intensity Stations
||(Tohoku District) 87
||(Tohoku District) 25