Rapid Detection of Earthquake Rupture Directivity Using Strong Ground Motion Data in Taiwan

Cheng-Feng Wu,Ting-Li Lin,Ying-Chi Chen

doi:10.5194/egusphere-egu2020-22441

Abstract

&lt;p&gt;In the past decade, there have been several disaster earthquakes occurred in Taiwan.&lt;br&gt;From the observed data of the disaster earthquakes, the stations located in the source&lt;br&gt;rupture direction have obvious directivity pulses, and the distribution of the earthquake&lt;br&gt;disaster is related to the peak ground velocity. Therefore, how to use a large and high-&lt;br&gt;dense seismic database to develop a near-real-time detection system on the earthquake&lt;br&gt;rupture directivity, which is a very important task in Taiwan. In this study, we determine&lt;br&gt;the earthquake rupture directivity using near-field velocity data from 1991 to 2018, which&lt;br&gt;were collected under the Taiwan Strong Motion Instrument Program (TSMIP). The used&lt;br&gt;method is mainly constructed in the interpolation of the peak-ground-velocity map and&lt;br&gt;the directional attenuation regression analysis. Through the analysis of moderate-to-large&lt;br&gt;magnitude (M L &gt; 5.5) seismic events, the source rupture directivity can be detected&lt;br&gt;effectively and quickly by the applied method. The detection results are also comparable&lt;br&gt;with those from the previous source studies. We also find out a linear relationship between&lt;br&gt;the directivity effect and earthquake magnitude. Since the TSMIP station may provide&lt;br&gt;real-time services in the future, the detection system proposed by this research can quickly&lt;br&gt;provide disaster prediction information, which is of great importance for earthquake&lt;br&gt;emergency response and hazard mitigation.&lt;/p&gt;

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