High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet

南极西部冰盖 ITASE 横断面下方冰雪地层的高分辨率雷达剖面图

• 批准号: 0088035
• 负责人: Steven Arcone
• 金额: $ 3.32万
• 依托单位: Department of Army Cold Regions Research & Engineering Lab
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0088035&HistoricalAwards=false
• 关键词: Resolution; Radar; Profiling; Snow; Ice

0088035 ArconeThis award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the InternationalTrans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitativelyassess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radarwill also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program.

0088035 Arcone该合同支持继续获取沿国际跨南极科学考察队(U.S.-ITASE)美国部分的穿越路线规划的核心地点之间的高分辨率雷达反射冰雪地层剖面。其目的是利用这些剖面来建立数百公里以上降雪地层层位的结构和连续性，并定量评估地形和冰移对积雪的影响。其他目标是确定单个地点所代表的气候范围，并调查降雪反射的原因。雷达还将用于识别导线车辆前面的裂缝，以保护导线上科学家和辅助人员的安全。与ITASE其他研究人员的合作将使用雷达地平线作为岩心测年固定的连续等时参考，以计算历史积雪率。一次雷达系统使用400 MHz(中心频率)短脉冲天线，这种天线(经过处理)可以穿透50-70米。这是沿导线路线超过200年沉积层位所需的深度。如果对深度大于70米感兴趣，还将记录200 MHz的剖面。处理将通过数据压缩(叠加)来完成，以揭示远距离地层变形，距离增益校正以赋予信号幅度适当的权重，以及GPS校正以调整当前冰盖地形的记录。近地表地层学将使地形和冰移的影响分开。这项工作对美国-ITASE项目的成功至关重要。