冲绳海槽北段的重磁场特征及地质意义

１９９２年之前，国内对冲绳海槽的调查研究主要集中在海槽的中部和南部，而对其北段的调查研究工作却很少。根据实测的重磁异常，较深入地分析了海槽北段的地球物理场特征，构造活动地壳结构及应力状态，结果表明冲绳海槽北段同样具有强烈的地壳构造活动。

GRAVITY AND MAGNETIC CHARACTERISTICS OF THE NORTH PART OF THE OKINAWA TROUGH AND GEOLOGICAL INTERPRETATION

Different from surveys before 1992,this investigation result shows that the north part of the Okinawa Trough has the same intensive modern crustal tectonic activities as the south part such as intensive magmatic activity,frequent earthquakes,high heat flow,well developed grabens,active faults and thinning lithosphere and crust. From calculations,the crustal thickness of the Okinawa Trough is from 18km to 26km,thinner than typical continental crust but thicker than typical oceanic crust and thus a typical transitional type.Great positive space anomaly over the Trough means extreme excess material below it.The mantle uplift gives a large floating force which thins the Moho and puts the crust into nonisostatic state.