Collaborative Research: Paleohistory of the Larsen Ice Shelf System: Phase II

合作研究：拉森冰架系统的古历史：第二阶段

• 批准号: 0338220
• 负责人: Scott Ishman
• 金额: --
• 依托单位: Southern Illinois University at Carbondale
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2009-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0338220&HistoricalAwards=false
• 关键词: Collaborative; Research; Paleohistory; Larsen; Ice

The Larsen Ice Shelf is the third largest ice shelf in Antarctica and has continued a pattern of catastrophic decay since the mid 1990's. The proposed marine geologic work at the Larsen Ice Shelf builds upon our previous NSF-OPP funding and intends to test the working hypothesis that the Larsen B Ice Shelf system has been a stable component of Antarctica's glacial system since it formed during rising sea levels 10,000 years BP. This conclusion, if supported by observations from our proposed work, is an important first step in establishing the uniqueness and consequences of rapid regional warming currently taking place across the Peninsula. Our previous work in the Larsen A and B embayments has allowed us to recognize the signature of past ice shelf fluctuations and their impact on the oceanographic and biologic environments. We have also overcome many of the limitations of standard radiocarbon dating in Antarctic marine sequences by using variations in the strength of the earth's magnetic field for correlation of sediment records and by using specific organic compounds (instead of bulk sediment) for radiocarbon dating. We intend to pursue these analytical advances and extend our sediment core stratigraphy to areas uncovered by the most recent collapse of the Larsen B Ice Shelf and areas immediately adjacent to the Larsen C Ice Shelf. In addition to the core recovery program, we intend to utilize our unique access to the ice shelf front to continue our observations of the snow/ice stratigraphy, oceanographic character, and ocean floor character. Sediment traps will also be deployed in order to measure the input of debris from glaciers that are now surging in response to the ice shelf collapse. This proposal is a multi-institutional, international (USAP, Italy, and Canada) effort that combines the established expertise in a variety of disciplines and integrates the research plan into the educational efforts of primarily undergraduate institutions but including some graduate education. This is a three-year project with field seasons planned with flexibility in order to accommodate schedules for the RVIB L.M. Gould. The Antarctic Peninsula is undergoing greater warming than almost anywhere on Earth, perhaps associated with human-induced greenhouse effects. Our proposed work contributes to understanding of these changes where they are occurring first and with greatest magnitude and impact upon the environment.

拉森冰架是南极洲第三大冰架，自 20 世纪 90 年代中期以来一直持续着灾难性的衰退。拟议的拉森冰架海洋地质工作以我们之前的 NSF-OPP 资助为基础，旨在检验以下工作假设：拉森 B 冰架系统自海平面上升 10,000 年来形成以来，一直是南极洲冰川系统的稳定组成部分血压。如果得到我们拟议工作的观察结果的支持，这一结论是确定目前整个半岛快速区域变暖的独特性和后果的重要的第一步。我们之前在拉森 A 和 B 海湾的工作使我们能够认识到过去冰架波动的特征及其对海洋和生物环境的影响。我们还通过利用地球磁场强度的变化来关联沉积物记录以及使用特定的有机化合物（而不是散装沉积物）进行放射性碳测年，克服了南极海洋序列中标准放射性碳测年的许多局限性。我们打算追求这些分析进展，并将我们的沉积岩心地层学扩展到拉森 B 冰架最近崩塌所覆盖的区域以及紧邻拉森 C 冰架的区域。除了核心恢复计划外，我们还打算利用我们独特的冰架前沿通道来继续观察雪/冰地层、海洋特征和海底特征。还将部署沉积物收集器，以测量冰川碎片的输入，这些碎片目前因冰架崩塌而激增。该提案是一项多机构、国际（USAP、意大利和加拿大）的努力，结合了各个学科的既定专业知识，并将研究计划整合到主要是本科机构但包括一些研究生教育的教育工作中。这是一个为期三年的项目，现场季节规划灵活，以适应 RVIB L.M. Gould 的日程安排。南极半岛正在经历比地球上几乎任何地方都更严重的变暖，这可能与人类引起的温室效应有关。我们提出的工作有助于了解这些变化首先发生的地方，以及对环境影响最大的地方。