Strong motions during the 2007 Niigata-Chuetsu-oki earthquake at down-hole sites in the Kashiwazaki-Kariwa Nuclear Power Station

Digitizing the pen-writing monitoring-record and estimation of strong motions at depths

Abstract

Two down-hole array strong-motion digital records on IC-memory cards at the Kashiwazaki-Kariwa Nuclear Power Station of Tokyo Electric Power Company during the main shock of the 2007 Niigata-Chuetsu-oki earthquake (Mj=6.8) were overwritten by succeeding aftershocks due to the less memory-capacity of the recording system. However, the monitoring pen-writing records were remained; therefore, we tried to retrieve the waveforms during the main shock by digitizing the pen-writing records using a CAD system and we prepared the report for estimating the strong-motions at some down-hole sites.