Collaborative Research: Chronology of Ice Fluctuations in the South Shetland Islands Since the Last Glacial Maximum

合作研究：自末次盛冰期以来南设得兰群岛冰涨落的年代学

• 批准号: 0338141
• 负责人: John Stone
• 金额: $ 8.39万
• 依托单位: University of Washington
• 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: 2004-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0338141&HistoricalAwards=false
• 关键词: Collaborative; Research; Chronology; Ice; Fluctuations

This award supports a study of the timing of climate changes in the Southern Hemisphere with the goal of reconstructing former ice extent and fluctuations, as well as paleoclimate, along the key latitudinal transect from temperate Tierra del Fuego to the polar Antarctic Peninsula. Samples already in hand will allow the dating of ice fluctuations in the South Shetland Islands (SSI), a critical location where that transect crosses the Antarctic Convergence. Surprisingly little concrete evidence exists concerning former ice extent in the island chain. The results of this study will answer a number of basic questions regarding ice extent and the timing of subsequent deglaciation in the Antarctic Peninsula. A cosmogenic exposure-age chronology will be produced from samples collected at carefully selected moraines on King George and Livingston Islands. A preliminary age of 18,000 years for a large granodiorite boulder from the outer moraine at Marian Cove suggests that the moraine may represent the Last Glacial Maximum (LGM) ice position. These data point to the potential for developing a ~20,000-yr record of ice fluctuations in the SSI, something that has not been achieved previously. Such data could be used not only to settle the long-standing debate over LGM ice extent in the SSI, but also would be valuable in assessing the global synchrony of large climate changes. Both a graduate and undergraduate student will be involved. This work builds on the recent success in dating glacial deposits in the Antarctic as young as 300 years using Beryllium-10 (10Be), as well as on an unexpected opportunity to map moraines and collect exposure-age samples in the SSI in 2002/2003. This research will produce a new understanding of the timing of ice fluctuations in the SSI, the extent and thickness of former ice cover, and may allow the development of a glacial chronology extending from the LGM to the late Holocene. This work will also provide a basis for inter-hemispheric comparisons of climate change and fits within the constraints of the Pole-Equator-Pole (PEP 1) transect to develop high-resolution, well-dated paleoclimate records in the Americas and Antarctic Peninsula.

该奖项支持对南半球气候变化的时机的研究，其目的是重建以前的冰范围和波动以及古气候，沿着从温带Tierra del Fuego到极地南极半岛的关键纬度样品。 已经掌握的样品将允许南开兰州群岛（SSI）的冰波动的日期，这是一个关键的位置，该位置横穿南极收敛。令人惊讶的是，关于岛屿连锁店以前的冰范围的具体证据很少。这项研究的结果将回答许多有关冰范围的基本问题以及南极半岛随后的脱气的时间。从乔治国王和利文斯顿群岛上精心挑选的莫拉尼斯收集的样品中，将产生一种宇宙的暴露年代年表。 来自玛丽安湾（Marian Cove）外部的大型颗粒状巨石的初步年龄为18，000岁，这表明冰ora可能代表了最后的冰川最大（LGM）冰位。这些数据表明，在SSI中产生约20,000年的冰波动记录的潜力，这是以前尚未实现的。此类数据不仅可以用来解决SSI中LGM ICE范围的长期辩论，而且在评估巨大气候变化的全球同步方面也很有价值。研究生和本科生都将参与其中。这项工作是基于最近使用铍10（10BE）在南极的冰川沉积物的最新成功，以及在2002/2003年在SSI中绘制Moraines并收集暴露年龄样本的意外机会。这项研究将对SSI中冰波动的时机，以前的冰覆盖的程度和厚度产生新的了解，并可能允许从LGM延伸到晚期全新世的冰川年表的发展。 这项工作还将为气候变化的半球间比较提供基础，并在钢管备孔（PEP 1）样带的约束中拟合，以在美洲和南极半岛发展高分辨率，良好的古气候记录。