Verification and Applicability of “Recipe” of Predicting
Strong Ground Motions for Inland Crustal Earthquakes
Kojiro IRIKURA1, Susumu KURAHASHI2, Ken MIYAKOSHI3
1. Aichi Institute of Technology, Japan, irikura@geor.or.jp
2. Aichi Institute of Technology, Japan
3. Geo-research Institute, Japan

ABSTRACT
Slip heterogeneities inside rupture areas of large earthquakes have been found from the results of the waveform inversion
using strong motion data. Destructive ground motions including short-period components are generated from such
heterogeneities. Asperities are defined as areas with large slip based on slip distributions from the waveform inversion. We
confirmed that the areas generating strong ground motions coincide with the asperities mentioned above. Then, we define acharacterized source model with asperities in an entire rupture area for simulating strong ground motions. We found thatground motions from recent inland-crust earthquakes are well simulated using the characterized source model. Then wedeveloped a “recipe” to construct the characterized source model for predicting strong ground motions.
This recipe gives source modeling for earthquakes caused to specific active faults obtained from geological, geomorphological surveys and geophysical investigations and two kinds of the scaling relationships for the fault parameters.
One is the conventional scaling relations such as rupture area versus seismic moment and fault slip versus seismic moment.
The other is the new ones such as asperity area versus seismic moment and asperity slip versus seismic moment. Based onsuch scaling relationships, the source model for predicting strong ground motions is characterized by the outer, inner, andextra fault parameters. The outer fault parameters are to outline the overall pictures of the target earthquakes such as entire
source area and seismic moment. The inner fault parameters are parameters characterizing stress heterogeneity inside thefault area. The extra fault parameters are considered to complete the source model such as the starting point and propagation
pattern of the rupture.
The verification and applicability of the procedures for characterizing the earthquake sources for strong ground prediction
are examined in comparison with the observed records and broad-band simulated motions for recent disastrous inland
earthquakes.
We show a case of the 2007 Chuetsu-oki (Mw 6.6) as one of examples. This earthquake occurred very close to theKasiwazaki-Kariwa Nuclear Power Plant. Ground motions from this earthquake are well simulated based on thecharacterized source model. We also examined the applicability of the recipe to other recent disastrous earthquakes such as
the 2007 Noto-hanto earthquake, 2005 Fukuoka earthquake, and so on.
We find the “recipe” is useful for predicting design ground motions for earthquake safety designs as long as the source fault
is specified through investigation of active folds and faults and the fault parameters are given considering regional
characteristics.
Key words: strong motion prediction, recipe, characterized source model, asperity, active fault, 2007 Chuetsu-oki
earthquake.

PRESENTER’S BIOGRAPHY
Professor of Aichi Institute of Technology, Professor Emeritus of Kyoto University, Main Subjects: Strong Motion
Seismology, Seismic Hazard Analysis