Of those, there were
14 with a magnitude over 5,
30 with a magnitude of 5,
174 with a magnitude of 4,
707 (magnitude 3),
1,904 (magnitude 2)
and 3,928 (magnitude 1), the agency said on its website.
For the whole year, the agency said there were 9,723 earthquakes and aftershocks, seven times the number in 2010.
An agency official said that although the number of aftershocks has been decreasing, it will be many years before seismic activity returns to pre-March 11 levels.