Seismic activity on the border of Tochigi and Gumma Prefs.

An M4.1 earthquake occurred on 6 February in area (b) at a depth of 11km. Activity in this area intensified in early January and ended in mid-February. Also, microearthquake activity has been continuing since mid-February in area (d). Moreover, there was activity in December, with a maximum M4.1 event, in area (d) on the southeast side of area (b).

Japan Meteorological Agency

Seismic Activity in Japan February 2000