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DomeA(冰穹A)位于东南极冰盖中央,是南极冰盖最高点.冰盖演化模式显示,DomeA区域很可能保存了过去超过百万年的地球古气候和古环境记录,被认为是深冰芯钻孔的理想位置.冰厚和冰下地形是模式评估冰芯年代尺度和深冰芯钻孔选址的重要依据.中国第21次和24次南极科学考察(CHINARE 21,2004/05;CHINARE 24,2007/08)期间,车载冰雷达系统被用于DomeA区域中心30km×30km范围内冰盖的三维调查,成功获得高分辨率、高精度冰厚和冰下地形数据,得出140.5m×140.5m网格分辨率冰厚分布和冰下地形DEM.调查结果显示,DomeA中心方形区域内的冰厚平均值为2233m,冰厚最小值1618m,昆仑站位置冰厚最大,为3139m;冰下地形起伏相对剧烈,海拔范围949～2445m,呈现典型、清晰的山地冰川作用地貌格局,很可能反映了冰盖早期的演化过程.依据冰厚分布和冰下地形特征,认为昆仑站位置适合开展首支分辨率高、年代久远深冰芯的钻探.不过,冰盖内部层序结构和冰底消融情况仍需进一步研究确定.
DomeA is located in the center of the East Antarctic Ice Sheet and is the highest point of the Antarctic ice sheet.The evolution of the ice sheet shows that the DomeA region is likely to have preserved the Earth’s paleoclimatic and paleoenvironmental records over the past million years and is considered to be deep Ice core drilling ideal location.Ice thickness and ice topography is an important basis for the model to evaluate ice core chronology and deep ice core drilling site.China’s 21st and 24 Antarctic Scientific Expeditions (CHINARE 21, 2004/05 ; CHINARE 24, 2007/08), the on-board ice radar system was used for three-dimensional investigation of ice sheets in the 30-km × 30-km radius of the DomeA area. The high-resolution, high-precision ice thickness and ice topography data were successfully obtained, yielding 140.5 m × 140.5m grid resolution ice thickness distribution and ice topography DEM.The results show that the average ice thickness in the center of DomeA is 2233m and the minimum ice thickness is 1618m.The maximum ice thickness at Kunlun Station is 3139m, Under the ice, the terrain undulates violently, with an elevation range of 949 ~ 2445m, showing a typical and clear glacial geomorphological pattern, which may reflect the early evolution of ice sheet.According to ice thickness distribution and ice topography, To carry out the first high resolution, However, the internal structure of the ice sheet and the ice-bottom ablation still need to be further studied and confirmed.