Bedmap2: improved ice bed, surface and thickness datasets for Antarctica
Bedmap2: improved ice bed, surface and thickness datasets for Antarctica
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DOI：
10.5194/tc-7-375-2013
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发表时间：
2013-01-01
期刊：
影响因子：
5.2
通讯作者：
Zirizzotti, A.
中科院分区：
文献类型：
--
作者：
Fretwell, P.;Pritchard, H. D.;Zirizzotti, A.
我们提出了Bedmap2，一套新的网格化产品，描述了南纬60度以南的南极洲的表面高程、冰厚度、海底和冰下床高程。我们使用来自各种来源的数据得出这些产品，包括自2001年原始Bedmap汇编（Bedmap1）以来完成的许多实质性调查。特别是，Bedmap 2冰厚网格由2500万次测量值组成，比Bedmap 1中使用的多两个数量级。在南极洲的大部分地区，冰川下地貌的可见度比以前高得多，许多地区数据覆盖范围的改善显示了山脉、山谷、盆地和海槽的全貌，而以前在当地调查中只显示了其中的一些片段。Bedmap 2的衍生统计数据显示，南极冰盖中所含的冰量（2700万km（3））及其对海平面上升的潜在贡献（58 m）与Bedmap 1相似，但冰盖的平均厚度要大4.6%，冰床平均深度降低72m，冰床面积增加10%。Bedmap2汇编突出显示了冰盖下的几个区域，这些区域的河床高程远低于Bedmap1所示的最深河床。这些产品沿着数据覆盖面和不确定性网格为详细模拟南极冰盖过去和未来的演变提供了新的机会。
We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60 degrees S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data-coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km(3)) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72m lower and the area of ice sheet grounded on bed below sea level is increased by 10 %. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.