Basic Study on Causes of Cut-off Frequency f_max of Earthquake

Abstract

In order to investigate causes of cut-off frequency f_max, that is important for strong ground motion prediction, we conducted deep seismic motion observations at depths of 300 m (Vs = 2.8 km/s) and 1000 m (Vs = 3.2 km/s) of hard rock site. As a result, we showed that high-cut filter based on f_max may correspond to an attenuation characteristic, so-called "bedrock characteristic", in a deep bedrock layer (generally corresponds to the 3.6 km/s layer) deeper than the seismic bedrock which had not been considered before.