Bedrock topography and wind erosion sites in East Antarctica: observations from the 2002 US-ITASE traverse
Bedrock topography and wind erosion sites in East Antarctica: observations from the 2002 US-ITASE traverse
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DOI：
10.3189/172756405781813258
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发表时间：
2005
影响因子：
2.9
通讯作者：
B. Welch;R. Jacobel
中科院分区：
文献类型：
--
作者：
B. Welch;R. Jacobel
摘要：2002 年美国国际横贯南极科学考察 (US-ITASE) 穿越过程中收集的深穿透雷达数据的冰地层显示，有证据表明存在明显的侵蚀面和漂流盆地，该盆地与大力神圆顶（南纬 87°420，西经 108°）和南极之间先前未发现的 1400 m 冰下山有关。 3MHz 雷达剖面图以与冰流方向成 458 度左右的角度穿过三座冰下山脉。冰地层顶部 500m 处的横切反射体被解释为当山顶上的冰变形时风蚀造成的角度不整合。不整合面与雷达卫星高反射率区域局部相关。邻近导线的几个附近地点具有类似的相对较高的雷达卫星反射率，表明这些地点也可能正在发生活跃的风蚀。根据地表风冲刷和冰下地形之间的局部相关性，我们解释了附近明亮的雷达卫星反射率簇，以表明存在小范围的冰下山脉。利用浅层和深层雷达追踪与冲刷地点相关的等时地层到附近的定年冰芯的能力，提供了利用风冲刷区域以利用浅层取芯设备获取年代清楚的较旧冰的可能性。
Abstract Ice stratigraphy from deep-penetrating radar data collected during the 2002 US International Trans-Antarctic Scientific Expedition (US-ITASE) traverse shows evidence of a significant erosion surface and drift-filled basin related to a previously undiscovered 1400m subglacial mountain between Hercules Dome (87˚420 S, 108˚ W) and South Pole. The 3MHz radar profile crosses three subglacial mountains at approximately 458 to the ice-flow direction. Cross-cutting reflectors in the top 500m of ice stratigraphy are interpreted as angular unconformities resulting from wind erosion as the ice deforms over the mountain tops. The unconformities correlate locally with zones of high RADARSAT reflectivity. Several nearby sites with similar relatively high RADARSAT reflectivity adjacent to the traverse indicate that active wind erosion may be taking place at these locations as well. Based on the local correlation between surface wind scour and subglacial topography, we interpret the nearby cluster of bright RADARSAT reflectivity to indicate the presence of a small range of subglacial mountains. The ability to trace isochronal stratigraphy, associated with scour sites using shallow and deep radar, to nearby dated ice cores presents the possibility of exploiting wind-scour zones to access well-dated older ice with shallow-coring equipment.