Physical and Structural Properties of the Siple Dome Core

该奖项旨在支持一项研究南极西部simple Dome冰芯的视觉地层学、指数物理性质、松弛特性和晶体结构的项目。这项调查将包括时间优先性质的测量，必须在钻探现场对新钻的岩心进行测量。对于来自脆性冰带的岩芯来说尤其如此，预计这些岩芯将占冰芯的很大一部分。脆性区包括冰，其中由围压释放引起的松弛最大，导致岩心的力学状况发生重大变化，这在处理和分析冰样品以进行捕获气体和化学研究时必须考虑到。这种松弛将通过在钻探现场进行的精确密度测量进行监测，并在美国间隔进行重复测量。其他研究将包括测量岩心的年度分层，直至可以破译视觉地层学的深度，测量作为深度和年龄函数的晶体尺寸，c轴结构研究，以及分析任何含碎屑基冰的物理性质及其与下垫基岩的关系。只有通过仔细记录和分析这些关键属性，我们才能希望准确地评估冰的动态状态和年龄-深度关系，这对破译这个地方的古气候记录至关重要。

This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.