Altimetry-Derived Gravity Predictions of Bathymetry by the Gravity-Geologic Method
Altimetry-Derived Gravity Predictions of Bathymetry by the Gravity-Geologic Method
复制标题
DOI：
10.1007/s00024-010-0170-5
复制
发表时间：
2011-05-01
影响因子：
2
通讯作者：
Doh, Seong-Jae
中科院分区：
文献类型：
--
作者：
Kim, Jeong Woo;von Frese, Ralph R. B.;Doh, Seong-Jae
重力地质方法 (GGM) 在以南极洲德雷克海峡沙克尔顿断裂带东端为中心的 1.6 度经度 x 1.0 度纬度区域进行了 20 x 20 次测深测量。 GGM 使用布格板近似来处理卫星测高得出的海洋自由空气重力异常和韩国海洋研究与发展研究所的 6,548 个当地船载测深测量数据，以更新周围的偏离轨道测深数据。通过建立稳定 GGM 预测的“调整”密度，可以缓解布格板在模拟可变密度的重力效应、距离长达数公里的崎岖测深地形时的局限性。使用三分之二的船载测深测量值来估计剩余三分之一的测试表明，调谐密度将均方根偏差最小化至约 29 m。尽管局部差异高达几公里，但尊重所有船舶观测结果的最佳 GGM 测深模型与广泛使用的测深模型具有很好的相关性。随着新的重力和测深探测数据的出现，GGM 的分析简单性有助于准确有效地更新测深数据。此外，海洋自由空气重力异常数据的可用性确保 GGM 比简单地将船舶测深覆盖范围外推或内插到未绘制地图的区域更有效。
The gravity-geologic method (GGM) was implemented for 20 by 20 bathymetric determinations in a 1.6 degrees longitude-by-1.0 degrees latitude region centered on the eastern end of the Shackleton Fracture Zone in the Drake Passage, Antarctica. The GGM used the Bouguer slab approximation to process satellite altimetry-derived marine free-air gravity anomalies and 6,548 local shipborne bathymetric sounding measurements from the Korea Ocean Research and Development Institute to update the surrounding off-track bathymetry. The limitations of the Bouguer slab for modeling the gravity effects of variable density, rugged bathymetric relief at distances up to several kilometers, were mitigated by establishing 'tuning' densities that stabilized the GGM predictions. Tests using two-thirds of the shipborne bathymetric measurements to estimate the remaining third indicated that the tuning densities minimized root-mean-square deviations to about 29 m. The optimum GGM bathymetry model honoring all the ship observations correlated very well with widely available bathymetry models, despite local differences that ranged up to a few kilometers. The great analytical simplicity of GGM facilitates accurately and efficiently updating bathymetry as new gravity and bathymetric sounding data become available. Furthermore, the availability of marine free-air gravity anomaly data ensures that the GGM is more effective than simply extrapolating or interpolating ship bathymetry coverage into unmapped regions.