Using a Structure Correction Method to Improve the Location Accuracy of the Hotan Seismic Array

Abstract

A structure correction method is investigated and used to improve the location results of the Wenchuan, Pishan, and 171 other earthquakes using the Hotan seismic array data. Systematic slowness anomalies are found between frequencywavenumber analysis and the location results from the China Earthquake Network Center, and all slowness error vectors point to about 300°. It is found that the back-azimuth and slowness errors change from positive to negative as the back-azimuth of different ray paths turns from north to south and from east to west, respectively. This phenomenon can be attributed to a dipping layer beneath the array with strike, dip, and velocity contrast of 210°, 45°, and 0.78, respectively. After correction for this dipping structure, the location results of the two main sequences are improved by 25.5% and 70.8% in terms of back-azimuth and slowness, respectively. Moreover, the location results of the other 171 earthquakes are improved by 28.5% and 7.1% in terms of back-azimuth and slowness, respectively.

Continental Earthquakes: Physics, Simulation, and Data Science—Introduction

“…Wu et al (2019) discussed the basic principles of phase-coded technology and conducted synthetic and experimental evaluations of two different CET implementations. Hao and Li (2019) compared the locations of 173 earthquakes (including the 2008 Wenchuan earthquake) using the Hotan seismic array data and those from the China Earthquake Network Center (CENC). By such comparison they identified a dipping layer beneath the array, which is useful for the 'structure-correction' of the seismic array processing.…”