List of foreshocks and aftershocks of the 2011 Tōhoku earthquake


This is a list of foreshocks and aftershocks of the 2011 Tōhoku earthquake. Japan had experienced 900 aftershocks after the M9.1 earthquake on March 11, 2011 with about 60 aftershocks being over magnitude 6.0 and three over magnitude 7.0. For conciseness, only earthquakes with magnitudes greater than 7.0 or an intensity greater than lower-6 on the shindo scale are listed here. Mw refers to the moment magnitude scale, while Mjma, Mjma, or Mj refer to the Japan Meteorological Agency seismic intensity scale.

Foreshocks

Main shock

Aftershocks

Possibly related earthquakes

The following earthquakes are possibly related to the 2011 Tōhoku earthquake. However, agreement toward the relationships has not been reached among the researchers.
Japan TimeMagnitudeCoordinatesDepthIntensity Comment
2011-03-12 03:59Mw 6.3, Mj 6.78 km
2 km		upper 6Possibly a triggered earthquake.
2011-03-12 04:31Mj 5.91 kmlower 6Possibly a triggered earthquake.
2011-03-12 05:42Mj 6.32 kmlower 6Possibly a triggered earthquake.
2011-03-15 22:31Mw 6.0, Mj 6.49 kmupper 650 injured. Power outage. Near presumed location of magma chamber of Mount Fuji.
Sinistral strike-slip fault. Possibly a triggered earthquake.

USGS

Other