Sensor Misorientation of CHINArray-II in Northeastern Tibetan Plateau from P- and Rayleigh-Wave Polarization Analysis

Abstract

Accurate sensor orientation is important in providing reliable data used for seismological analysis such as P-wave receiver function analysis, shear-wave splitting, and ambient noise analysis. In this study, we used three distinct P-wave and Rayleigh-wave polarization analysis methods to estimate actual sensor orientation of 660 stations from CHINArray-II in northeastern margin of Tibetan plateau. We found that ∼42.12%–45.76% of the stations are well oriented with the absolute misorientation angle <3°, 42.42%–45.45% of the stations are fairly oriented with the absolute misorientation angle ranging from 3° to 10°, and 8.94%–11.82% of the stations are oriented with the absolute misorientation angle >10°. We further compared the results of some seismological analyses before and after sensor misorientation correction, such as Rayleigh-wave ellipticity (horizontal-to-vertical ratio) and P-wave receiver functions analysis. We found that when the sensor misorientation angle is large, it may lead to incorrect seismological results. With the same sensor misorientation, its influence on different seismological analysis is also different.