Deep crustal imaging by wide-angle seismic data using seismic interferometry

海底地震仪（OBS）获得的广角地震反射和折射调查数据对于限制长波地震速度和深部结构是有效的，但OBS的大间距（通常为5或6公里）阻碍了我们应用波形反演和地震偏移等波形分析技术。地震干涉测量法（SI）有可能克服这一困难，因为我们可以通过将SI应用于OBS数据，将稀疏的海底接收器集重设为密集的海面接收器集。利用叠前深度偏移（PSDM）技术合成的密集广角数据，可以实现高分辨率地震构造成像。研究了SI + PSDM方法有效成像精细地震构造的技术细节。因此，我们仅使用稀疏的OBS数据就成功地对深度超过10km的海底、沉积物和深反射体进行了成像。

Wide-angle seismic reflection and refraction survey data obtained by Ocean Bottom Seismometers (OBSs) are effective for constraining long-wavelength seismic velocities and deep structures, but the large OBS spacing, typically 5 or 6 km, prevents us from applying waveform analysis techniques like waveform inversion and seismic migration. Seismic Interferometry (SI) has a potential to overcome this difficulties, because we can redatum sparse sea floor receiver gathers into dense sea surface receiver gathers by applying SI to OBS data. The syntheseized dense wide-angle data enable us to image high-resolution seismic structure by applying Pre-Stack Depth Migration (PSDM). We studied technical details for effective imaging of detailed seismic structure by SI + PSDM method. Consequently, we successfully imaged seafloor, sediments, and deep reflectors at a depth of more than 10km by using only sparse OBS data.