During cruise TS03 in the Southern Mariana Trench,a series of active and passive seismic surveys were carried out using Ocean Bottom Seismometer(OBS)produced in China,aiming at cross-trench crustal structure and local seismicity.However,abnormal direct-water-wave events were found on the seismic section of POBS04,and a large GAP between data files was also noticeable during data processing.These abnormal data bring uncertainty to the following relocation of OBSs and seismic tomography.To analyze these abnormal data,arrival times of direct water wave were calculated and then compared with the air-gun signals in SAC file.Our results show that the internal time of POBS04 was incorrect because of data missing,which then resulted in early arrival of air-gun signals.Based on these findings,we delayed the arrival time of air-gun signals in SAC software to be identical to calculated arrival time of direct water wave.After that,correct SEGY file can be converted and plotted.This study reveals a new kind of abnormal data.This procedure assists in OBS relocation and seismic tomography,and provides new references for abnormal data correction and OBS upgrade.
关键词
海底地震仪(OBS)/数据丢失异常/内部时间校正/挑战者深渊
Key words
Ocean Bottom Seismometer(OBS)/Abnormal data missing/Internal time correction/Challenger Deep
维普
万方数据