利用测高重力梯度异常反演中国南海海底地形

Recovery of Ocean Depth Model of South China Sea from Altimetric Gravity Gradient Anomalies

摘要: 根据位理论和挠曲均衡补偿理论,推导了重力梯度异常垂直分量与海深之间的关系。利用Geosat、ERS-1/2、T/PJ、ason-1、EnviSat-1卫星测高数据计算得到的南海海域重力梯度异常垂直分量,采用FFT求解法,反演了南海海域的海底地形,并与LDEO船测海深数据进行了比较,两者之差的RMS较大,在大于5 000m的海域达到了595.1 m。

Abstract: Based on the theory of potential and flexural isostatic compensation,the relationship between ocean depth and the vertical component of gravity gradient anomalies is derived.Using the vertical component of gravity gradient anomalies computed with Geosat,ERS-1/2,T/P,Jason-1,EnviSat-1 altimeter data,the ocean depth model of the South China Sea is predicted using a FFT method.Then the predicted ocean depth model is compared with LDEO ocean depth.The RMS of the difference between the predicted model and LDEO achieves 591.7 m when ocean depth is greater than 5 000 m.