Tohoku Region

a) On February 10, there was a M5.4 earthquake (maximum seismic intensity 4) off-shore of Fukushima prefecture.
b) Since February 13, there was a series of earthquakes off-shore of Sanriku and a M5.5 earthquake was the largest (maximum seismic intensity 1).
c) On February 27, there was a M5.2 earthquake (maximum seismic intensity 3) off-shore of Fukushima prefecture.

J-EGG500 from the Japan Oceanographic Data Center, GTOPO30 from the US Geological Survey, and ETOPO2v2 from the National Geophysical Data Center in the U.S. were used for the topographic and bathymetric data.

[Earthquake(s) mentioned have one or more of the following features: M6.0 or greater or maximum seismic intensity 4 or greater, M4.5 or greater and maximum seismic intensity 3 or greater on shore, M5.0 or greater and maximum seismic intensity 3 or greater in the ocean area.]

N: total number of events in the figure

Japan Meteorological Agency
Ministry of Education, Culture, Sports, Science and Technology
[Seismic Activity for February 2011 (March 9, 2011)]