摘要
分析研究了南黄海和东海地区18口石油勘探钻井的井孔崩落特征，结合对琉球岛弧和冲绳海槽地区浅源地震震源机制解的分析，确认了南黄海地区与我国华北地区有类似的现代构造应力场特征；并得出东海地区的最大水平压应力方向为NEE-SWW，最小水平压应力方向为NNW-SSE，它们分别与冲绳海槽地区的最大和最小主压应力方向接近;东海地区地壳上层的水平差应力可能不强，这与该地区没什么地震活动的特点是一致的．根据应力场特征推断，我国东部地区并未受到菲律宾海板块俯冲的推挤作用，而是可能受到垂直于冲绳海槽走向的拉伸作用的影响．
On the basis of borehole breakouts analysis of 18 oil wells in the sea basins and focal mechanism data of shallow earthquakes in the Okinawa trough and Ryukyu arc region, the present-day crustal tectonic stress in the southern Yellow Sea and East China Sea region is studied. On the new evidence mis paper establishes that the Yellow Sea region shows similar directions of principal stress axes as that in North China. The result of thes study indicates that for the East China Sea region the maximum principal compression is in the direction of NEE-SWW, while the minimum compression is in NNW-SSE, both roughly coinciding with the corresponding principal stress directions in the Okinawa trough. It is qinte possible that the differential horizontal stress is rather weak in the East China Sea region, where moderate and strong earth quakes have not been seen. From the characteristics of crustal stress we can infer that eastern China may be affected by the tension in a direction perpendicular tO the trending of the Okinawa trough, instead of suffering from the push of the PhiliPPine Sea plate.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第6期773-781,共9页
Chinese Journal of Geophysics
基金
国家自然科学基金
关键词
构造应力场
井孔崩落
南黄海
东海
震源
地震
Tectonic stress, Borehole breakouts, Southern Yellow Sea, East China Sea
