Lambert冰川流域物质平衡和南极冰盖变化

Mass Balance in the Lambert Glacier Basin and Variability of the Antarctic Ice Sheet

对Lambert冰川流域的现场考察资料和浅冰芯研究结果显示 ,该流域东侧和西侧积累速率分布和过去几十年的变化具有明显差异 :东侧平均积累速率较西侧高 ;近 5 0年东侧处于增加状态 ,西侧则为明显减小。冰量平衡计算表明 ,该冰川流域目前处于物质正平衡状态 ,因而冰盖将趋于增厚。据现有资料估计分析 ,整个南极冰盖处于微弱负平衡。如果南极地区气候变暖 ,物质平衡将向正平衡方向发展 ,因而不会引起海平面上升。但是西南极冰盖的不稳定性可能随气候持续变暖而增强 ,成为引起海平面上升的最重要潜在因素。

The snow accumulation measurements and shallow core studies carried out in recent years show that the accumulation is higher in east than in west parts of the Lambert Glacier basin.According to the mass budget calculations,the ice flux across a investigation route is larger than the total accumulation over the upstream area were calculated,meaning that the Lambert Glacier basin is in a positive mass balance and hence the ice thickness will be increasing.Based on the data available,it is believed that Antarctic Ice Sheet is in a thin negative mass balance.If climate is worming,the mass balance of the ice sheet will tend to be positive,which will not result in sea level rise.However,the instability of West Antarctic Ice Sheet will increase with the climatic worming and thus will become the most important in the factors causing the sea level rise.