Late Quaternary History of the Western and East-Central Ross Sea, Antarctica: A Contribution to the West Antarctic Ice Sheet Initiative

南极洲西部和中东部罗斯海的晚第四纪历史：对南极西部冰盖计划的贡献

• 批准号: 9615046
• 负责人: Amy Leventer
• 金额: --
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9615046&HistoricalAwards=false
• 关键词: Late; Quaternary; History; Western; East

OPP 9614287 Andrews OPP 9615046 Leventer Abstract The late Quaternary extent and pattern of retreat of the West Antarctic Ice Sheet is an important control on interpretation of ice core records from the region and it has important ramification regarding the global water budget (in sea level terms), the timing of meltwater contributions to the ocean, and the synchrony (or lack thereof) between events in the Northern and Southern Hemispheres. This award supports continued research on the chronology of ice retreat from the western Ross Sea and an extension of areal coverage for this research to include the eastcentral Ross Sea. The study will use a series of piston, Kasten, and grab samples from research cruises in 1994 and 1995 on the RVIB N.B. Palmer by researchers from Rice University, University of Colorado, Boulder, and Hamilton College. Various physical and biological parameters of the cores will be used to map changes in the environments over time with a concentration on sediment properties, foraminifera, and diatoms. At this time, ninety-two carbon-14 dates (plus 18 pending dates, all based on acceleratormass-spectrometry) have been obtained from cores collected prior to 1994 and from the 1994 and 1995 cruises by the research groups at Hamilton College and the University of Colorado, Boulder. Emphasis will be placed on obtaining additional radiocarbon dates supplemented by several other chronological methods including: sources and ages of volcanic ashes, uranium-series dating of solitary corals, and amino acid racemization. The three major research questions are: 1) What was the position of the grounding line during the Last Glacial Maximum from the western to east-central Ross Sea and what was the timing of retreat from this limit, was it synchronous across the region, and what was the rate of retreat ? 2) Is there evidence from the history of carbonate accumulation on the outer shelf banks, and from cores on the slope of the Ross Sea that the ice was grounded on the shelf break at some time prior to marine isotope stage (MIS) 2, possibly at MIS 4 (Goodwin, person. commun. 1996)? 3) What are the paleoenvironments in the areas of the Ross Sea at the millenial/century time-scales during the latest Pleistocene and the Holocene? In particular, what is the history of changes in surface water productivity and sea ice extent?

OPP 9614287 Andrews OPP 9615046 Leventer 摘要 南极西部冰盖晚第四纪的范围和退缩模式是对该地区冰芯记录解释的重要控制因素，并且对全球水预算（以海平面而言）具有重要影响、融水对海洋贡献的时间，以及北半球和南半球事件之间的同步性（或缺乏同步性）。 该奖项支持继续研究罗斯海西部冰退缩的年代学，并将这项研究的区域覆盖范围扩大到包括罗斯海中东部。 该研究将使用一系列活塞、Kasten，并从 RVIB N.B. 1994 年和 1995 年的研究巡航中采集样本。 Palmer 是由莱斯大学、科罗拉多大学博尔德分校和汉密尔顿学院的研究人员设计的。 岩心的各种物理和生物参数将用于绘制环境随时间的变化图，重点关注沉积物特性、有孔虫和硅藻。 目前，汉密尔顿学院和大学的研究小组已从 1994 年之前以及 1994 年和 1995 年航行中收集的岩芯中获得了 92 个碳 14 年代（加上 18 个待定日期，全部基于加速器质谱法）科罗拉多州博尔德。重点将放在获得额外的放射性碳测年上，并辅之以其他几种年代学方法，包括：火山灰的来源和年龄、孤立珊瑚的铀系列测年以及氨基酸外消旋化。 三个主要的研究问题是：1）末次盛冰期从罗斯海西部到东部中部的接地线位置是什么，从这个界限退缩的时间是什么，整个地区是否同步，以及撤退率是多少？ 2) 外陆架岸碳酸盐堆积的历史以及罗斯海斜坡上的岩心是否有证据表明冰在海洋同位素阶段（MIS）2之前的某个时间在陆架断裂处接地，可能是在 MIS 4（Goodwin，person.commun.1996）？ 3）在最新世和全新世的千年/世纪时间尺度上，罗斯海地区的古环境是什么？特别是地表水生产力和海冰范围的变化历史是怎样的？