本文利用由多源卫星测高资料计算的新版全球重力异常Grav_Alti_WHU，联合船测水深资料，构建了全球75°S—70°N范围的1'×1'海底地形模型BAT_WHU2020。以船测水深、现有模型和多波束测深数据为参考，对模型精度进行了分析评价。结果表明，在中国海域及邻区（104°E—160°E，0°N—50°N），本文模型与船测水深之差值的标准差约70 m，与SIO V19.1模型精度相当，优于ETOPO1、DTU10、GEBCO_08等模型，较此前发布的BAT_VGG模型精度提高了约30%，说明本文模型构建方法可靠、数据处理准确、精度较高。在全球范围内，BAT_WHU2020模型与船测水深之差值的标准差为50~65 m，差值在±200 m范围内的比率超过95%，与SIO V19.1模型精度相当，优于ETOPO1、DTU10、GEBCO_08等模型，较BAT_VGG模型精度提高了27%~36%。以SIO V19.1模型为参考，模型之差的标准差为90~110 m，约90%格网点差值在±200 m以内，约95%格网点差值在±300 m以内，两者一致性良好。最后，讨论了地壳均衡、Parker公式高次项等对成果精度的影响，模型的真实空间分辨率，以及以多波束测深为参考的模型精度问题。分析认为，BAT_WHU2020模型空间分辨率为10~18 km，在马里亚纳海沟、麦夸里海岭地区相对精度为5%~6%。

In this paper, a 1'×1' bathymetry model BAT_WHU2020 in the range of 75°S—70°N is constructed by using the latest version of the global gravity anomaly model derived from the multi-source satellite altimetry data and the shipboard depths. The accuracy of the model is analyzed and evaluated based on ship depths, existing models and multibeam soundings. The standard deviation of the difference between the proposed model and the ship depths in China Sea and its adjacent areas (104°E—160°E, 0°N—50°N) is about 70 m, which is equivalent to the accuracy of SIO V19.1 model, superior to ETOPO1, DTU10, GEBCO_08 model, and about 30% higher than the accuracy of BAT_VGG model published before, which shows that the method in this paper is reliable, and the data processing is accurate and the accuracy is high. The standard deviation of the differences between BAT_WHU2020 model and ship depths is about 50~65 m globally, and the ratio of the difference within ±200 m is greater than 95%. It is showed that the accuracy of BAT_WHU2020 model is equivalent to SIO V19.1, better than ETOPO1, DTU10, GEBCO_08 model, and improved about 27%~36% from the BAT_VGG model. Comparing to SIO V19.1 model, the standard deviation of the model differences is about 90~110 m, about 90% of the grid differences is within 200 m, and about 95% is within 300 m. Finally, the effects of crustal isostasy and high order terms in the Parker's formula on the accuracy of the results, the accuracy of the model compared to multibeam soundings, and the spatial resolution are discussed. It indicates that the spatial resolution of BAT_WHU2020 model is about 10~18 km, and the relative accuracy is about 5%~6% around the Mariana trench and Macquarie ridge.

根据重力地质法（GGM），利用南中国海海域内63179个船测控制点水深将测高自由空间重力异常划分为长波参考场和短波残差场，并反演出了该海域112°E—119°E，12°N—20°N范围的1’×1’海底地形模型，该过程中使用的海水和海底洋壳密度差异常数1.32 g·cm^-3通过实测水深估计得到.利用反演得到的GGM模型对剩余的10529个检核点船测水深插值计算后与实测水深进行比较，其较差结果的均值为-1.64 m，标准差为76.95 m，相对精度为4.06%.此外，根据船测点数量、分布和海底地形的不同，选择了三个海域进行统计，结果表明：在船测控制点分布均匀的海域，GGM模型精度优于ETOPO1模型，在控制点过于分散的海域其精度会有所下降，但好于船测水深的直接格网化结果.为进一步探究检核点的较差结果中出现较大数值的成因，本文对精度较差的点位进行了单独分析，选择了两条船测航迹剖面进行了研究，并分析了检核点的水深较差、相对精度与水深和重力异常的关系，结果表明：GGM模型精度受水深和重力异常的相关性影响较小，受海底地形复杂程度影响较大，地形坡度变化平缓海域的预测精度明显高于海山地区.最后，综合GGM模型和ETOPO1模型优势，利用所有船测水深作为控制，生成了综合的海底地形模型.

The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South China Sea. What data are available, however, and if Hong Kong is used, as it is herein, as an indicator of what the perturbations of other regional cities upon the South China Sea are like, then it is impacted grossly and an ecological disaster has probably already, but unknowingly, happened.

Gravity models are powerful tools for mapping tectonic structures, especially in the deep ocean basins where the topography remains unmapped by ships or is buried by thick sediment. We combined new radar altimeter measurements from satellites CryoSat-2 and Jason-1 with existing data to construct a global marine gravity model that is two times more accurate than previous models. We found an extinct spreading ridge in the Gulf of Mexico, a major propagating rift in the South Atlantic Ocean, abyssal hill fabric on slow-spreading ridges, and thousands of previously uncharted seamounts. These discoveries allow us to understand regional tectonic processes and highlight the importance of satellite-derived gravity models as one of the primary tools for the investigation of remote ocean basins. Copyright © 2014, American Association for the Advancement of Science.