南海北部海陆过渡带地壳结构的研究现状及展望

首先总结了前人在南海北部海陆过渡带获得的研究成果：由重磁异常、水深及卫星影像等资料推测滨海断裂带存在于南海北部海陆过渡地区：介绍了最近在南海北部海陆过渡地区开展的海陆地震联测试验，其结果显示有一个穿透整个地壳的低速破碎带发育于海陆过渡地区，推测它为滨海断裂带在速度上的表现，另外广泛分布于华南大陆的中地壳低速层在海陆过渡处也有较好发育；总结了天然地震层析成像在南海北部海陆过渡带的研究成果。最后结合目前的研究现状，指出了今后我们的研究方向：在逐步完善目前海陆地震联测试验的基础上，同时开展海陆过渡带的多道地震数据采集及地球化学研究：加强海陆过渡带的地震监测。进行震源机制解和人工地震与天然地震联合成像的研究。

Situation and Prospect of Study on Crustal Structure beneath the Onshore-Offshore Transitional Zone in the Northern Margin of South China Sea

This paper first summarizes the results of previous studies：（1） it is indicated that a fault zone （called Littoral Fault Zone） exists beneath the onshore-offshore transitional zone in the northern margin of South China Sea, according to the gravity and geomagnetic anomalies, water depths and satellite images; （2） a low velocity zone going through the crust was imaged in the northeastern and middle northern of transitional zone respectively by using the onshore-offshore seismic experiment, which may denote Littoral Fault Zone. The low velocity layer in the middle ernst widely developing in South China also was identified in the transitional zone; （3） we give a review on the results of seismic tomography. Combined with recent researches, this paper also gives some prospects on the future study： perfecting the onshore-offshore seismic experiment; carrying out the MCS experiment; using the geochemical method to study the characteristics of the petrology; imaging the deep structure using the man-made and natural seismic data together; monitoring earthquakes occurred in the onshore-offshore transitional zone, and studying the focal mechanisms.