【摘要】 给出海底地形起伏与垂直重力梯度异常之间的响应函数关系。据此,联合船测海深和垂直重力梯度异常数据,构建了全球75°S—70°N范围内1′×1′海底地形模型。以船测海深为检核参考,考察了本文模型在印度洋南部和西北太平洋地区的精度。结果表明,在考察区域内,本文模型精度优于ETOPO1、GEBCO和DTU10模型,且在印度洋南部与SIO的最新海底地形模型V15.1精度相当,在西北太平洋地区略优于V15.1。探讨了高次项和地壳均衡现象的影响量级,发现两者对反演结果的影响很小,可以忽略。通过与重力异常反演结果的比较,发现垂直梯度异常反演在中短波长部分(100~200km)表现较优。在西北太平洋地区,联合重力异常和垂直梯度数据进行海底地形反演计算,反演结果的精度较V15.1模型提高了约29.5%,说明联合这两种数据可以计算精度更高的海底地形模型。更多还原

【Abstract】 The response function between bathymetry and vertical gravity gradient anomalies is derived.A global bathymetry model was formed using vertical gravity gradient anomalies and ship soundings based on the response function.The latitude rang of the model is 75°S—70°N and the resolution is 1′×1′.Comparing to ship soundings,the accuracy of the model in South India Ocean and Northwest Pacific was evaluated.The result shows that,in the discussed region,the accuracy of the model predicted in this paper is better than ETOPO1,GEBCO and DTU10,and in Northwest Pacific,the accuracy is slightly better than the latest V15.1model from SIO,the accuracy in South India Ocean is consistent with V15.1.The influence of high order terms and crust isostasy were discussed.It found that both of the two factors have nearly no effect on the result and can be ignored.The predicted model was compared with the model formed using gravity anomalies too.The result shows that,in the wave length 100 to 200km,the vertical gravity gradient anomalies are preferred to gravity anomalies.In Northwest Pacific,comparing with V15.1,the accuracy of the predicted model is increased by about 29.5%when these two kinds of data were combined.It indicates that a bathymetry model of higher accuracy can be formed combining gravity anomalies and vertical gravity gradient anomalies.更多还原