Collaborative Research: Western Divide West Antarctic Ice Cores (WAISCORES) Site Selection

该奖项支持一项地面地球物理测量计划，以详细绘制冰流、积累速率、内部分层和冰厚度的空间变化，这些地点已被确定为在西南极洲钻探下一个深冰芯的有希望的地点。主要的调查工具是利用高频和低频探冰雷达对内层和河床的地形进行成像，利用GPS重复测量计算现今地表速度场，利用合成孔径雷达（SAR）干涉测量计算区域速度场，利用短岩心计算现今积累速率。收集到的数据将被用来作为随时间变化的冰流和温度模型的输入，这些模型将预测年龄、冰层厚度和温度的深度变化。除了在钻探前对预期条件进行估计外，模型预测与最终从岩心中恢复的数据之间的不匹配将有助于推断该地区的变薄和气候（积累和温度）历史。在罗斯海海湾和阿蒙森海之间的西部分水岭已被确定为最符合为深钻地点制定的标准的区域。利用航空地球物理方法进行的初步选址已经确定了西部分水岭上几个可能的钻探地点，在那里气候记录应该得到最好的保存。这项工作将在很大程度上为南极洲西部下一个深冰芯的最终选址做出贡献。

This award supports a program of ground-based geophysical measurements to map in detail the spatial variations of ice flow, accumulation rate, internal layering and ice thickness at the sites which have been identified as promising locations to drill the next deep ice core in West Antarctica. The main investigative tools are a high- and low-frequency ice penetrating radar to image the topography of internal layers and the bed, repeat GPS surveys to calculate the present day surface velocity field, synthetic aperture radar (SAR) interferometry to calculate the regional velocity field, and short firn cores to calculate present day accumulation rates. The data which will be collected will be used to as input to time-dependent ice flow and temperature models that will predict depth variation of age, layer thickness, and temperature. As well as yielding an estimate of expected conditions before drilling, the mismatch between the model prediction and data eventually recovered from the core will help infer thinning and climate (accumulation and temperature) histories for the region. The Western Divide, between the Ross Sea Embayment and the Amundsen Sea, has been identified as the region which best satisfies the criteria which have been established for a deep drilling site. Preliminary site selection using airborne geophysical methods has identified several potential drill sites on the Western Divide where the climate record should be best preserved. This work will contribute in a major way to the final site selection for the next deep ice core in West Antarctica.