New Additional Correction Terms for Attenuation Relations of Peak Amplitudes and Response Spectra Corresponding to the Anomalous ismic Intensity in Northeastern Japan

Abstract

We improved additional correction terms for empirical attenuation relations to represent anomalous seismic intensity of subduction zone. New additional terms for the empirical attenuation relations by Kanno et al.(2005) were determined not only for peak values but also for response spectra. We introduced distance from the volcanic front, instead of the trench axis, to observation site as a new parameter of the correction term, which is reflecting anomalous Q structure beneath northeast Japan, and the distance from volcanic front was a better explanation than the distance from trench. The coverage of the correction terms extended up to longitude 138 degree east. We also inspected dependence on source characteristics between interplate and intraslab events. The dependence of ground motion amplitude on the event category was considerable, even without the focal depth identification.