ATTENUATION RELATION OF JMA SEISMIC INTENSITY APPLICABLE TO NEAR SOURCE REGION

Abstract

Using about 28,000 records from over 500 events up to August 2005, we determined an attenuation relation of JMA (Japan Meteorological Agency) seismic intensity, which is applicable to near source region. The determined attenuation relation was verified by comparing with data of recent earthquakes: the 2003 Off Tokachi, Off Miyagi and 2004 Chuetsu earthquakes of inter-plate, slab and crustal events respectively. Fairly agreement can be seen in these comparisons at close distance to the source. Iso-seismic intensity area by our relation is well corresponding to results of previous studies.