Characterizing the glaciological conditions at Halvfarryggen ice dome, Dronning Maud Land, Antarctica
Characterizing the glaciological conditions at Halvfarryggen ice dome, Dronning Maud Land, Antarctica
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DOI：
10.3189/2013jog12j134
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发表时间：
2013-03
影响因子：
3.4
通讯作者：
R. Drews;C. Martín;D. Steinhage;O. Eisen
中科院分区：
文献类型：
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作者：
R. Drews;C. Martín;D. Steinhage;O. Eisen
摘要：我们提出了一种综合方法（包括现场数据、遥感和各向异性冰流模型）来描述南极洲沿海 Dronning Maud 地 Halvfarryggen 冰穹的特征。这是冰芯科学国际合作伙伴关系的潜在钻探地点，该合作伙伴关系已确定需要冰芯来覆盖过去几千年的大气条件。我们从雷达数据中推导出表面地形、冰地层，以及由于首选风向和变化的表面坡度而在 400 到 1670 kg m−2 a−1 之间变化的累积率。地层学显示了分水岭下方的背斜和向斜。我们将 Dansgaard-Johnsen 年龄深度尺度从等时线的侧面转移到冰厚度上部 20-50% 的分界线，并表明它们与全斯托克斯各向异性冰流模型的结果进行了很好的比较，该模型预测 (1) 11 ka BP 冰在冰厚度的 90% 处，(2) 至少 2700-4500 年的时间稳定分界线，(3)基础温度低于熔点（−12°C 至 -5°C）；(4) 高度发达的晶体取向织物（COF）。我们建议钻入深层背斜的顶端，在记录长度和时间分辨率之间提供良好的折衷，并促进各向异性 COF 和冰流相互作用的研究。
Abstract We present a comprehensive approach (including field data, remote sensing and an anisotropic ice-flow model) to characterize Halvfarryggen ice dome in coastal Dronning Maud Land, Antarctica. This is a potential drill site for the International Partnerships in Ice Core Sciences, which has identified the need for ice cores covering atmospheric conditions during the last few millennia. We derive the surface topography, the ice stratigraphy from radar data, and accumulation rates which vary from 400 to 1670 kg m−2 a−1 due to preferred wind directions and changing surface slope. The stratigraphy shows anticlines and synclines beneath the divides. We transfer Dansgaard–Johnsen age–depth scales from the flanks along isochrones to the divide in the upper 20–50% of the ice thickness and show that they compare well with the results of a full-Stokes, anisotropic ice-flow model which predicts (1) 11 ka BP ice at 90% of the ice thickness, (2) a temporally stable divide for at least 2700–4500 years, (3) basal temperatures below the melting point (−12°C to −5°C) and (4) a highly developed crystal orientation fabric (COF). We suggest drilling into the apices of the deep anticlines, providing a good compromise between record length and temporal resolution and also facilitating studies of the interplay of anisotropic COF and ice flow.