基于改进的FA2BOUG法研究北极美亚海盆区域的布格重力异常特征

Calculation of Bouguer gravity anomaly in the Arctic Amerasia Basin based on improved FA2BOUG method

为获得更为精确的北极美亚海盆区域的布格重力异常特征,利用最新发布的全球空间重力异常数据、水深数据和沉积层厚度数据,采用改进的FA2BOUG法计算了该区的布格重力异常值。计算过程中考虑到沉积物效应,进行了等效地形转换,让其替换FA2BOUG法中的原始水深数据进行完全布格校正(Bullard A、B和C)。结果显示,北极美亚海盆的布格重力异常介于150×10^-5~400×10^-5 m/s^2之间,深海地区数值较大,且由深海地区逐渐向海岸带附近逐渐变小,而海岭地区主要在200×10^-5 m/s^2左右变化。

In order to obtain more accurate Bouguer gravity anomaly characteristics in the Amerasia Basin,an improved FA2 BOUG method is adopted in this study to calculate the Bouguer gravity anomaly in this area by using the latest published free-air gravity anomaly data,bathymetric data,and sediment thickness data.Considering the sedimentary effect during the calculation,an equivalent terrain transformation was performed to replace the original bathymetric data in the FA2 BOUG method with a complete Bouguer correction(Bullard A,B and C).The results show that the Bouguer gravity anomaly in Amerasia Basin ranges from 150×10^-5 to 400×10^-5 m/s^2.The value in the deep sea area is larger and it gradually decreases from the deep sea area to the coast,whereas the value in the ridge areas varies around 200×10^-5 m/s^2.