Bellingshausen Sea bathymetric compilation

The southern Bellingshausen Sea (SBS) is a rapidly-changing part of West Antarctica, where oceanic and atmospheric warming has led to the recent basal melting and break-up of the Wilkins ice shelf, the dynamic thinning of fringing glaciers, and sea-ice reduction. Accurate sea-floor morphology is vital for understanding the continued effects of each process upon changes within Antarctica's ice sheets. Here we present a new bathymetric grid for the SBS compiled from shipborne echo-sounder, spot-sounding and sub-ice measurements. The 1-km grid is the most detailed compilation for the SBS to-date, revealing large cross-shelf troughs, shallow banks, and deep inner-shelf basins that continue inland of coastal ice shelves. The troughs now serve as pathways which allow warm deep water to access the ice fronts in the SBS. Our dataset highlights areas still lacking bathymetric constraint, as well as regions for further investigation, including the likely routes of palaeo-ice streams. The new compilation is a major improvement upon previous grids and will be a key dataset for incorporating into simulations of ocean circulation, ice-sheet change and history. It will also serve forecasts of ice stability and future sea-level contributions from ice loss in West Antarctica, required for the next IPCC assessment report in 2013.别林斯高晋海南部（Southern Bellingshausen Sea, SBS）是西南极洲变化最为迅速的区域之一，海洋与大气变暖已引发近期威尔金斯冰架（Wilkins Ice Shelf）的底部消融与崩解、沿岸冰川的动态变薄以及海冰减少。精准的海底地貌数据是理解各过程对南极冰盖内部变化持续影响的关键基础。本研究构建了一套针对SBS的全新测深网格（bathymetric grid），该数据集整合了船载回声测深仪（shipborne echo-sounder）、定点测深（spot-sounding）与冰下测量（sub-ice measurements）获取的观测数据。这套分辨率为1千米的网格是迄今为止针对SBS最详尽的测深汇编成果，揭示了大型跨陆架槽、浅滩以及延伸至沿岸冰架内陆区域的深层陆架内盆地。这些槽谷如今成为暖深层水抵达SBS冰前缘的主要通道。本数据集同时明确了当前仍缺乏水深约束的区域，以及有待开展进一步研究的区域——包括古冰流（palaeo-ice streams）的潜在流经通道。这套全新的测深汇编成果相较此前的网格实现了大幅改进，将成为融入海洋环流（ocean circulation）、冰盖变化与演化历程模拟的关键数据集，同时也将服务于冰体稳定性以及西南极洲冰损引发的未来海平面上升贡献预测，而这些内容是2013年下一届政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）评估报告所需的核心支撑依据。