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

该奖项支持一个项目，为正在进行的南极西部冰盖分裂（WAIS）深冰芯提供冰稳定同位素（Delta-D, Delta-O18）的基石分析之一。WAIS Divide钻探项目是一个多机构合作的项目，旨在获得南极洲中西部连续的高分辨率冰芯记录，该项目在2010年初达到了2560 m的深度；预计需要一到两个季节才能到达冰盖床（约3300米），再加上额外的四个季节进行钻孔测井和其他活动，包括拟议的重复取心。目前的提案要求支持完成对WAIS Divide岩芯到基地的分析，那里的年龄将达到~100,000年或更长。这些分析将成为研究末次冰川期气候和冰川学中许多悬而未决的问题的基础，这些问题的重点是南极西部冰盖的动态，以及南极西部气候与北极地区、热带太平洋和全球其他地区气候的关系，时间尺度从几年到几万年不等。这项工作的一个新方面是，华盛顿大学在利用同位素示踪剂建立环流模型的气候建模方面越来越多的专业知识，这将有助于对数据的解释。另一个重要的新方面是在科罗拉多大学完成并使用了高分辨率、半自动采样系统，该系统将允许通过激光光谱连续分析同位素比率，有效分辨率为~2厘米或更小，为大部分岩心提供年际时间分辨率。由于稳定冰同位素的连续流分析是一种相对较新的测量方法，我们将在华盛顿大学使用传统的离散采样和质谱分析，每~10-20米进行平行测量，以补充它们。这项工作的智力价值和总体目标是看到内陆WAIS成为西南极洲的参考冰同位素记录。这项工作的更广泛影响是，本项目产生的数据直接涉及与政策相关的紧迫问题，如南极西部冰盖的稳定性，以及过去和未来的海平面变化，以及南方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的现代同位素分析技术的发展，其应用范围远远超出冰芯。该项目将包括一名研究生和一名博士后，他们将与两家私家侦探一起工作，并在两家机构花时间。数据将通过南极冰川学数据中心迅速提供，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.