Collaborative Research: Resolving centennial- to millennial-scale trends in glacier extent and lake sedimentation in the Brooks Range, Arctic Alaska

合作研究：解决阿拉斯加北极地区布鲁克斯山脉冰川范围和湖泊沉积的百年至千年尺度趋势

• 批准号: 1107885
• 负责人: William D'Andrea
• 金额: $ 11.27万
• 依托单位: Columbia 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: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1107885&HistoricalAwards=false
• 关键词: Collaborative; Research; Resolving; centennial; millennial

The goal of this collaborative project to reconstruct late Quaternary climate and glacier change in Arctic Alaska, one of few regions in the Arctic where mountain glaciers have left physical records of their former extent, making it valuable for comparing the timing and extent of mountain glacier variability between the lower latitudes and the Arctic. Several features of the climate and glacier history of the Brooks Range contrast with those from the North Atlantic region (which is often taken to represent the entire Northern Hemisphere in records of climate change) and currently available evidence indicates that the history of the Brooks Range more closely resembles glacier records from the southern Hemisphere. The investigators propose to develop records of climate change from lake sediments and records of glacier fluctuations using proglacial lake sediments and beryllium-10 dating of glacial features to address questions centered around four intervals of pronounced global change: (1) Last Glacial Maximum: Did glaciers retreat and temperatures increase in Arctic Alaska during the global LGM, as has been simulated by climate models? (2) Deglaciation: To what extent did climate change in Arctic Alaska coincide with North Atlantic climate fluctuations during deglaciation? (3) Holocene Glaciation: What was the extent of glaciers during (a) the Holocene thermal maximum, and (b) Neoglaciation? (4) Little Ice Age: Was it wetter or drier in the Brooks Range? The research will take place in suitable valleys (floatplane accessible valley with extant glaciers) in the north­central Brooks Range. The project has several educational components, including support four graduate students and several undergraduate students and visits to the community of Anaktuvuk Pass to deliver presentations on climate research and the Brooks Range. The proposed research aims to produce well-dated and quantitative records of glacier and climate variability in the northernmost glaciated region of the U.S. Documenting the past behavior of arctic glaciers when subject to extreme climate events during the late glacial period and warm intervals like the Holocene can provide valuable insight to help better predict responses to future change.

该合作项目的目标是重建北极阿拉斯加的晚第四纪气候和冰川变化，阿拉斯加是北极地区少数几个山地冰川留下了以前范围的物理记录的地区之一，这对于比较低纬度地区和北极之间山地冰川变化的时间和程度很有价值。布鲁克斯山脉的气候和冰川历史的几个特征与北大西洋地区的气候和冰川历史形成鲜明对比（在气候变化记录中，北大西洋地区通常被视为代表整个北半球），目前现有的证据表明布鲁克斯山脉的历史更接近于南半球的冰川记录。研究人员建议利用前冰川湖沉积物和冰川特征的铍 10 测年技术，开发湖泊沉积物中的气候变化记录和冰川波动记录，以解决围绕明显的全球变化的四个间隔的问题：（1）末次盛冰期：正如气候模型所模拟的那样，末次盛冰期期间阿拉斯加北极地区的冰川是否退缩且温度升高？ （2）冰消期：冰消期期间阿拉斯加北极地区的气候变化在多大程度上与北大西洋气候波动一致？ (3) 全新世冰川期：(a) 全新世最热期和 (b) 新冰川期期间冰川的范围有多大？ (4) 小冰河时代：布鲁克斯山脉是更湿润还是更干燥？该研究将在布鲁克斯山脉中北部合适的山谷（可通过水上飞机到达且有现存冰川的山谷）进行。该项目包含多个教育部分，包括支持四名研究生和几名本科生，以及访问 Anaktuvuk Pass 社区，发表有关气候研究和布鲁克斯山脉的演讲。拟议的研究旨在对美国最北端冰川地区的冰川和气候变化进行详细的定量记录。记录北极冰川在晚冰期和全新世等温暖时期遭受极端气候事件时的过去行为，可以提供有价值的见解，帮助更好地预测对未来变化的反应。