Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core

STEIG/1043092该奖项支持一个项目，该项目旨在为正在进行的西南极冰盖分水岭(WAIS)深冰芯贡献一项基石分析--冰的稳定同位素(Delta-D，Delta-O18)。WAIS Divide钻井项目是一个多机构项目，旨在从西南极中部获得连续的高分辨率冰芯记录，2010年初达到2560米的深度；预计还需要一到两个野外季节才能到达冰盖床(~3300米)，另外还需要四季进行钻孔记录和其他活动，包括拟议的重复取心。目前的提案要求支持完成对WAIS分水岭核心到基地的分析，那里的年龄将达到约10万年或更长时间。这些分析将构成对上一次冰期气候和冰川学中一些悬而未决问题的调查的基础，重点是西南极冰盖的动态以及西南极气候与北极地区、热带太平洋和地球其他地区气候的关系，时间尺度从数年到数万年不等。这项工作的一个新方面是华盛顿大学在使用同位素示踪剂启用的大气环流模型进行气候建模方面日益增长的专业知识，这将有助于解释数据。另一个重要的新方面是完成和使用科罗拉多大学的高分辨率半自动采样系统，该系统将能够以约2厘米或更低的有效分辨率通过激光光谱学连续分析同位素比率，为大部分岩芯提供年际时间分辨率。由于稳定冰同位素的连续流动分析是一种相对较新的测量方法，我们将使用传统的离散采样和华盛顿大学的质谱仪分析来补充它们，每隔10-20米进行平行测量。这项工作的学术价值和首要目标是看到内陆WAIS成为西南极的参考冰同位素记录。这项工作的更广泛影响是，该项目产生的数据直接涉及与政策有关的紧迫问题，即西南极冰盖的稳定性，以及海平面过去和未来的变化，以及南部高纬度地区气候变化的性质。该项目还将促进使用激光光谱学的现代同位素分析技术的发展，其应用远远超出冰芯。该项目将涉及一名研究生和博士后，他们将与这两家私人投资机构合作，并在两家机构都呆上一段时间。数据将通过南极冰川数据中心迅速提供，供其他研究人员和公众使用。

Steig/1043092This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.