Ocean circulation beneath Larsen C Ice Shelf, Antarctica from in situ observations
Ocean circulation beneath Larsen C Ice Shelf, Antarctica from in situ observations
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DOI：
10.1029/2012gl053187
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发表时间：
2012-10
影响因子：
5.2
通讯作者：
K. Nicholls;Keith Makinson;E. Venables
中科院分区：
文献类型：
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作者：
K. Nicholls;Keith Makinson;E. Venables
研究人员利用热水钻孔获取Larsen C冰架北部和南部两个地点的海洋数据。在这两个地点，整个水柱都低于地表冰点，温度-盐度特征与最高盐度34.65 psu的高盐度陆架水源一致。在南部站点，在8天的时间内，冰基0.08°C的热驱动和0.2 ms - 1 rms的水速导致融化速度为1.3±0.2 ma - 1。结合现有的船舶数据，有证据表明，冰下空洞只有在表面冰点时才会被水冲刷。这意味着报道的拉森C冰架表面海拔的下降不太可能是由于基底融化速度加快而变薄的结果。
Hot‐water drilled access holes were used to obtain oceanographic data from beneath two sites on Larsen C Ice Shelf, one in the north and one in the south. At both sites the entire water column was colder than the surface freezing point, and the temperature‐salinity characteristics are consistent with a High Salinity Shelf Water source of maximum salinity 34.65 psu. At the southern site the 0.08°C thermal driving at the ice base and the 0.2‐m s−1 rms water speed resulted in a melt rate of 1.3 ± 0.2 m a−1, as measured over an eight‐day period. When combined with the available ship‐based data, the evidence suggests that the sub‐ice cavity is flushed only by water at the surface freezing point. This implies that the reported decrease in surface elevation of Larsen C Ice Shelf is unlikely to be a result of thinning due to an increasing rate of basal melting.