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，为正在进行的西南极冰盖分水岭（WAIS）深冰芯提供基础分析之一，冰的稳定同位素（Delta-D，Delta-O 18）。WAIS分水岭钻探项目是一个多机构项目，目的是从西南极洲中部获得连续的高分辨率冰芯记录，该项目于2010年初达到2 560米的深度;预计还需要一个或两个实地季节才能到达冰盖床（~ 3 300米），另外还需要四个季节进行钻孔测井和其他活动，包括拟议的重复取芯。 目前的提案要求支持完成对WAIS分水岭核心到基底的分析，其中年龄将为10万年或更长。这些分析将成为调查末次冰期气候和冰川学中若干未决问题的基础，重点是南极西部冰盖的动态以及南极西部气候与北方极地地区、热带太平洋和地球仪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环流模型进行气候建模方面的专业知识不断增加，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一个高分辨率、半自动化取样系统，该系统将允许通过激光光谱法以约2厘米或更低的有效分辨率对同位素比率进行连续分析，为大多数岩芯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法，每隔~10-20 m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，该项目产生的数据直接涉及与政策有关的南极西部冰盖稳定性问题和当前问题，从而涉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。该项目还将有助于利用激光光谱学发展现代同位素分析技术，其应用范围远远超出冰芯。该项目将涉及一名研究生和博士后，他们将与两名PI一起工作，并在这两个机构工作。将通过南极冰川学数据中心迅速提供数据，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.