Collaborative Research: An Ultra-High Resolution Holocene Climate Record from a Varved Sediment Sequence from the Adelie Coast, Antarctica (IODP Exp 318)

合作研究：来自南极洲阿德利海岸的 Varved 沉积物序列的超高分辨率全新世气候记录 (IODP Exp 318)

• 批准号: 1129101
• 负责人: Robert Dunbar
• 金额: $ 22.14万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129101&HistoricalAwards=false
• 关键词: Collaborative; Research; Ultra; Resolution; Holocene

A key region for analysis of long- and short-term behavior of the East Antarctic Ice Sheet (EAIS) is the eastern sector of the Wilkes Land margin, located at the seaward termination of the largest subglacial basin in East Antarctica, the Wilkes subglacial basin. The Wilkes subglacial basin may in fact respond to climate variability in a fashion similar to the West Antarctic Ice Sheet. Additionally, a significant portion of all Antarctic Bottom Water may originate from this part of the Antarctic coast, making this region a key player in oceanic circulation patterns. The Integrated Ocean Drilling Program Expedition 318 to Wilkes Land recently obtained nearly 3,000 meters of sedimentary cores. Drill site U1357, obtained a unique ultra-high accumulation rate sedimentary sequence from the Adelie Basin that extends from the latest glacial interval through the Holocene. These seasonally laminated deposits constitute one of the world's most expanded archives of environmental change during the Holocene. The sediments contain a near annual-resolution record of when and how the ice sheet margin retreated from the shelf ~12,000 kyr B.P. They also contain a record of past changes in water temperature, water mass reservoir age, stratification, productivity, sea ice extent, and possibly bottom water production throughout the Holocene. In this collaborative proposal, the P.I.'s request funding for morphometric, stable isotopic, and geochemical analyses of foraminifera recovered from the sediment column. These will be used to produce the first high-resolution (sub-decadal to decadal) foraminiferal isotopic and chemical climate time series from the Antarctic margin.Intellectual Merit - The results from this project will provide, for the first time, the requisite data at subdecadal to decadal resolution to address a number of questions related to oceanographic and climatic changes that occurred on and around Antarctica during the Holocene, including: 1) How does the style and timing of deglaciation along the East Antarctic Margin compare with other parts of the Antarctic Margin? 2) What were the responses of the East Antarctic Margin glacial system to deglaciation as well as global and regional Holocene climate fluctuations? 3) How did oceanic circulation and bottom water production vary during the Holocene? As part of our post-expedition educational outreach, we will organize two additional interactive webcasts targeting science museums and secondary schools during the course of this research. At Stanford, we will continue to disseminate the results of this work to secondary schools via a funded NASA project wherein he is meeting regularly with science teachers from around the SF Bay Area. Additionally, we are engaging up to 8 undergraduate students at Queens College and Stanford University in the project as interns and will guide them through the process of envisioning

分析东南极冰盖（EAIS）长期和短期行为的一个关键区域是威尔克斯陆地边缘的东段，位于东南极洲最大的冰下盆地威尔克斯冰下盆地的向海终端。事实上，威尔克斯冰下盆地可能以类似于西南极冰盖的方式对气候变化做出反应。此外，所有南极底层水的很大一部分可能源自南极海岸的这一部分，使该地区成为海洋环流模式的关键参与者。综合海洋钻探计划 318 号远征队前往威尔克斯地最近获得了近 3000 米的沉积岩芯。钻探地点U1357，获得了阿德利盆地独特的超高堆积率沉积序列，该序列从最新的冰川期延伸到全新世。这些季节性层状沉积物构成了世界上全新世期间环境变化最丰富的档案之一。沉积物包含近年分辨率的记录，记录了冰盖边缘何时以及如何从陆架退缩，距今约12,000 kyr。它们还包含过去整个全新世水温、水体储层年龄、分层、生产力、海冰范围以及可能的底层水产量变化的记录。在这项合作提案中，PI 请求资助对从沉积物柱中回收的有孔虫进行形态测定、稳定同位素和地球化学分析。这些将用于产生南极边缘的第一个高分辨率（亚十年到十年）有孔虫同位素和化学气候时间序列。智力价值 - 该项目的结果将首次提供必要的数据十年间到十年间的决议，以解决与全新世期间南极洲及其周围发生的海洋学和气候变化有关的一系列问题，包括：1）与南极边缘其他地区相比，南极东部边缘的冰消减情况如何？ 2）南极东部边缘冰川系统对冰川消融以及全球和区域全新世气候波动有何反应？ 3）全新世期间海洋环流和底层水产量如何变化？作为我们探险后教育推广的一部分，我们将在本研究过程中组织两次针对科学博物馆和中学的额外互动网络广播。在斯坦福大学，我们将继续通过 NASA 资助的项目向中学传播这项工作的成果，在该项目中，他定期与旧金山湾区各地的科学教师会面。此外，我们还聘请了皇后学院和斯坦福大学的最多 8 名本科生作为实习生参与该项目，并将指导他们完成构想的过程