Earth Planets Space, Vol. 63 (No. 2), pp. 145-149, 2011
Yoshihiro Hiramatsu1, Misaki Hayashi2, Aiko Hayashi3, and the group for the joint aftershock observations of the 2007 Noto Hanto Earthquake
1School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
2Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
3Department of Earth Sciences, Faculty of Science, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
(Received July 16, 2010; Revised November 22, 2010; Accepted November 24, 2010; Online published February 28, 2011)
We investigate spatial distribution of similar aftershocks of a large inland earthquake using waveform data obtained by a dense temporary seismic network. Similar earthquakes on the source fault are mainly located around the deeper edge of the major asperity. The cumulative slip estimated from the similar earthquakes ranges from 0.6 to 2.7 cm and coincides with the slip estimated from postseismic crustal movement observed by GPS. The slip velocity estimated from both the slip and the recurrence interval of the similar earthquakes is larger at the edge of the asperity. These results suggest that the afterslip area is spatially complementary to the asperity on the fault surface for inland earthquakes similar to large interplate earthquakes on the plate interface.
Key words: Similar earthquake, asperity, afterslip, inland earthquake, the 2007 Noto Hanto earthquake.