Continuation of Physical Properties of the Greenland Ice Sheet Project II

9321261 Alley该奖项旨在支持一项为期三年的计划，继续对格陵兰冰盖项目二（GISP 2）冰芯进行物理性质测量和定年，重建积累率，并共同解释积累率，污染物和同位素记录。 GISP2冰芯的年代测定在很大程度上依赖于可见的地层，尽管其他指标也很关键。 GISP2核心较深部分的流动不连续性可能会使那里获得的气候记录无效。 因此，关键是要知道在什么深度的气候记录变得可疑。 幸运的是，流动不连续性具有物理特征，可以通过使用光学和声波技术研究颗粒的尺寸、形状和排列及其c轴来检测。 物理数据在冰流建模中也很重要，可以用来确定深冰芯的年代，并了解冰盖过去和未来的变化。 ***

9321261 Alley This award is for support for a three year program to continue the physical properties measurements and dating of the Greenland Ice Sheet Project Two (GISP2) ice core, reconstruct accumulation rates, and jointly interpret the accumulation rate, contaminant and isotopic records. Dating of the GISP2 ice core has relied most heavily on visible strata, although other indicators have been critical. Flow discontinuities in the deeper part of the GISP2 core could invalidate the climate record obtained there. It is thus critical to know at what depth the climate record becomes suspect. Fortunately, flow discontinuities have a physical signature that may be detected by study of the size, shape, and arrangement of grains and their c axes using optical and sonic techniques. Physical data are also important in ice flow modeling for dating of the deep ice core and for understanding any past and future changes in the ice sheet. ***