A joint microtremors measurement in the Fukui basin to discuss the effects of surface geology on seismic motion during the 1948 Fukui, Japan, earthquake

摘要

A joint research project on application of microtremors has been promoted since1997 with the support by the Ministry of Education, Science and Culture, Japan. One of principalresearch activities in 1997 was to have made a cooperative measurement of microtremors in theFukui basin. Because the 1948 Fukui earthquake was really a catastrophic disaster including 3,769death and 36,200 totally collapsed houses, but there was only a few information about seismic,geological and geotechnical data in the area. The joint microtremor measurements provided newtypes of information such as the distribution of predominant period, the distribution of amplificationcharacteristics due to local soil conditions and underground structure themselves. Such resultsenabled us to discuss the site effects comparing them with the 1995 Hyogoken-Nanbu (Kobe)earthquake for example.