Calibrations of Sensor Misorientation Angles for TASTE in Xinjiang and Its Influence on Measurement of SKS Wave Splitting

Based on the rigorous constraints on the data from the 66 broadband transportable stations of the Tarim seismic array for the lithospheric signature of mantle plume (TASTE), the calibrations of the sensor misorientation angles were achieved by three internationally commonly used methods — P-wave principal component analysis method, transverse P-wave energy minimization method and Rayleigh-wave correlation coefficient method. The results obtained from these three methods demonstrated remarkable consistency with correlations ranging from 0.64 to 0.91. Following the integration analysis, the final sensor misorientation angles were established. Among the stations, 62 stations exhibited relatively stable sensor orientations. None of the stations showed evidence of north-south reversals, nor did their sensor misorientation angles display systematically time-dependent variations. When compared with magnetic declination, it was observed that the sensor misorientation angles of 40 stations fell within ±3° of the magnetic declination. This suggests that the TASTE network experiences a low level of external interference, thereby ensuring the high quality of the station deployment. Two examples of SKS wave splitting were used to evaluate the influence of sensor misorientation angles on shear wave splitting measurements. The necessity of calibrating sensor misorientation angles in seismology was demonstrated.