S33C-4541:
Application of τc*Pd for identifying damaging earthquakes for earthquake early warning

Wednesday, 17 December 2014
Po-Lun Huang1, Ting-Li Lin1 and Yih-Min Wu2, (1)NCKU National Cheng Kung University, Tainan, Taiwan, (2)NTU National Taiwan University, Taipei, Taiwan
Abstract:
Earthquake Early Warning System (EEWS) is an effective approach to mitigate earthquake damage. In this study, we used the seismic record by the Kiban Kyoshin network (KiK-net), because it has dense station coverage and co-located borehole strong-motion seismometers along with the free-surface strong-motion seismometers. We used inland earthquakes with moment magnitude (Mw) from 5.0 to 7.3 between 1998 and 2012. We choose 135 events and 10950 strong ground accelerograms recorded by the 696 strong ground accelerographs. Both the free-surface and the borehole data are used to calculate τc and Pd, respectively. The results show that τc*Pd has a good correlation with PGV and is a robust parameter for assessing the potential of damaging earthquake. We propose the value of τc*Pd determined from seconds after the arrival of P wave could be a threshold for the on-site type of EEW.