Collaborative Research: Quaternary Paleoclimatic Evolution of the Larsen Basin, Offshore Seymour Island, Eastern Antarctic Peninsula

合作研究：南极半岛东部西摩岛近海拉森盆地第四纪古气候演化

• 批准号: 9419232
• 负责人: Thomas Davies
• 金额: $ 5.53万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9419232&HistoricalAwards=false
• 关键词: Collaborative; Research; Quaternary; Paleoclimatic; Evolution

Abstract This award supports a collaborative study of Quaternary glacial marine deposits of the Larsen Basin. These sedimentary deposits are uniquely suited for study of the Modern environmental setting and recent paleoclimatic evolution of the northeastern Antarctic Peninsula continental shelf, an area thought to exhibit pronounced sensitivity to climatic changes. Microfossils from these deposits and their stable isotope compositions provide information on varying oceanographic conditions, ice mass extent, and sediment dispersal. Questions to be answered include: 1) What are the faunal and isotopic responses to glaciation, both proximal and distal to the variety of small and medium ice masses in the area? 2) What is the relationship between physical evidence of ice position, as expressed in sediments and seismic data, and the faunal and isotopic signatures thereof? 3) To what extent is an environmental model of the highly variable interglacial Modern shelf applicable to describing and understanding late Quaternary environments representative of different climatic regimes? Preliminary results of a pilot study using surface and cored sediments indicate that foraminiferal assemblage composition and stable isotope ratios record highly variable Modern and late Quaternary environmental conditions. However, data are needed from a larger number of cores to reconstruct the Antarctic Peninsula late Quaternary environmental history. Methods to be employed in this research are foraminiferal and palynological analyses, foraminiferal carbon and oxygen isotope ratios, and carbon-14 measurements. The primary research objectives of the proposed one-year project are as follows: 1) Provide the first study for the Antarctic Margin Project for drilling in shallow water depths offshore of Seymour Island. The proposed work would serve to provide a sound environmental framework of the Quaternary deposits from which to interpret the Cenozoic record; 2) Establish the first Qua ternary stable isotope chronostratigraphy for Antarctic continental shelf sediments; 3) Document and interpret Quaternary climatic fluctuations, including proposed Holocene warming episodes, as they are preserved in the sediments, biota, and stable isotopic records, and reflect variations in local and regional ice buildup, physical and chemical oceanography, and sediment source areas. This research represents an important contribution to international global change studies.

摘要 该奖项支持对拉森盆地第四纪冰川海洋沉积物的合作研究。 这些沉积矿床特别适合研究南极半岛东北部大陆架的现代环境背景和近期古气候演化，该地区被认为对气候变化表现出明显的敏感性。这些沉积物中的微化石及其稳定同位素组成提供了有关不同海洋条件、冰块范围和沉积物扩散的信息。需要回答的问题包括： 1）该地区各种中小型冰块的近端和远端对冰川作用的动物区系和同位素反应是什么？ 2) 以沉积物和地震数据表示的冰位置的物理证据与其动物群和同位素特征之间有什么关系？ 3）高度变化的间冰期现代陆架的环境模型在多大程度上适用于描述和理解代表不同气候状况的晚第四纪环境？使用地表和岩心沉积物进行的初步研究的初步结果表明，有孔虫组合组成和稳定同位素比率记录了高度可变的现代和晚第四纪环境条件。 然而，需要大量岩心数据来重建南极半岛晚第四纪环境历史。本研究采用的方法是有孔虫和孢粉学分析、有孔虫碳和氧同位素比率以及碳 14 测量。 拟议的为期一年的项目的主要研究目标如下： 1）为南极边缘项目提供第一个在西摩岛近海浅水深度钻探的研究。 拟议的工作将有助于提供一个健全的第四纪矿床环境框架，从中解释新生代记录； 2）建立第一个南极大陆架沉积物四元稳定同位素年代地层学； 3）记录和解释第四纪气候波动，包括​​拟议的全新世变暖事件，因为它们保存在沉积物、生物群和稳定同位素记录中，并反映了当地和区域冰堆积、物理和化学海洋学以及沉积物源区的变化。 这项研究对国际全球变化研究做出了重要贡献。