Tohoku Region
# A dotted line shows the aftershock area of the 2011 off the Pacific Coast of Tohoku Earthquake.
① During February, within the aftershock area of "the 2011 off the Pacific Coast of Tohoku Earthquake," there were 11 earthquakes of M5.0 or over (refer to Kanto-Chubu Region). In addition, there were 3 earthquake with a maximum seismic intensity 4 or over.
② On February 17, there was a M6.9 earthquake (maximum seismic intensity 4) offshore Sanriku. In addition to tsunami with height of 27 cm at Kuji Port, Iwate prefecture, slight tsunami was observed along the Pacific coast from Hokkaido to Iwate prefecture. Afterwards in the vicinity of the epicenter, there was an active seismicity, such as a M6.5 earthquake (maximum seismic intensity 3) on 20th and a M6.4 (maximum seismic intensity 2) on 21th.
③ On February 17, there was a M5.7 earthquake(maximum seismic intensity 5 Upper) offshore Iwate prefecture.
④ On February 26, there was a M5.0 earthquake(maximum seismic intensity 4) offshore Miyagi 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, other earthquakes with remarkable activity.]
N: total number of events in the figure
Japan Meteorological Agency
Ministry of Education, Culture, Sports, Science and Technology
[Evaluation of Seismic Activities for February 2015 (March 10, 2015)]