日本DONET1海域地震动数据及其特征初步分析

本文介绍了日本南开海槽海底的密集型地震海啸网络监测系统(DONET1)及其获取的海域地震动记录基本情况,以及海域地震动的处理方法,分析了其海域地震动幅值、持时和频谱参数的基本特性,以期为DONET1记录的深入研究使用提供参考。分析结果表明:DONET1海域PGA的衰减率和日本陆地的衰减率有较大的差别,而PGV衰减率差别不大,但是整体上PGA和PGV值大于陆地衰减关系预测值;对典型的较大幅值的海域记录分析表明,其5%阻尼比加速度反应谱峰值周期点较大,与我国抗震设计规范相比,反应谱长周期段的谱值整体较大,表明其长周期分量比较丰富;70%和90%能量持时和全球衰减关系预测值相差不大。

Offshore ground motion data in DONET1 of Japan and preliminary analysis on its characteristics

This paper introduces the Dense Ocean Network for Earthquake and Tsunamis(DONET1)in Nankai trough in Japan,the basic information of the recorded offshore ground motion,and the processing method of the offshore motion.This paper analyzes the basic characteristics of the offshore ground motion amplitude,duration and spectrum parameters,so as to provide reference for further study of DONET1 records.The research results show that the attenuation rate of PGA in DONET1 offshore area is different from that of onshore area in Japan,while the attenuation rate of PGV is not significantly different,but on the whole the PGA and PGV values are larger than the prediction values of onshore attenuation relation;the analysis of typical offshore ground motions with large amplitudes shows that the period of maximum value for 5%damping response spectra is significantly large,and the ordinates of response spectra for long periods are larger compared with the seismic design standard,which indicates that the long period components of the offshore motion are more abundant;the prediction value of 70%and 90%significant duration are relatively close.