RUI Collaborative Proposal: Climate and Chronology of the Last Glacial-Interglacial Transition, North-Central Great Basin, U.S.A.

RUI 合作提案：美国中北部大盆地末次冰期-间冰期转变的气候和年代学

• 批准号: 0902586
• 负责人: Jeffrey Munroe
• 金额: $ 15.15万
• 依托单位: Middlebury College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0902586&HistoricalAwards=false
• 关键词: RUI; Collaborative; Proposal; Climate; Chronology

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Recent developments in the understanding of Pleistocene glacial records in the western U.S. reveal spatial variability in the onset of the last glacial-interglacial transition (GIT; the time ~17-10 ka) among the northern, middle, southern Rocky Mountains, and the central Colorado Plateau. Such variability may reflect differences in precipitation among these areas caused by shifts in the location of the polar jet and accompanying storm tracks, or possibly the importance of Great Basin pluvial lakes as moisture sources for downwind mountain ranges. In determining the extent, timing, and chronology of glacier and lake fluctuations in the north-central Great Basin, this project fills a broad spatial gap in the understanding of glacial and paleoclimate history in the western U.S., and provides a much needed addition to climate records used to validate regional climate models. Intellectual Merit: Numerous mountain ranges and intermountain valleys in the north-central Great Basin contain abundant evidence of glacier and pluvial-lake fluctuations during the last GIT. However, the timing of glacier and lake responses to climate changes during this transition is virtually unknown in this region, and the nature of temperature and/or precipitation changes during this interval of profound climate change is poorly understood. Using glacier and pluvial-lake records from this region to infer climate changes during the Latest Pleistocene is of great current interest for several reasons. First, the location of the Great Basin, central among well-dated glacial and pluvial-lake locales in the interior western U.S., provides significant potential for examining the response of climate-sensitive, small glaciers and lakes to climate changes associated with the retreat of North American ice sheets and accompanying reorganization of regional-scale atmospheric circulation. Second, the excellent preservation of glacial and pluvial-lake deposits provides ideal targets for cosmogenic-surface exposure dating and optically-stimulated luminescence (OSL) dating. Finally, the proximity of mountain glaciers to closed-basin pluvial lakes during the last GIT affords a rare setting in which combined numerical modeling of glacier and lake mass balance can be used to set narrow limits on paleo-temperature and precipitation. Broader Impacts: This research is carried out by faculty from two predominantly undergraduate institutions, and all aspects of field and analytical work are aided by student researchers from Middlebury College and SUNY Geneseo. Maps produced through this project are published by the Nevada Bureau of Mining and Geology, making the glacial history of these popular areas available to recreational users. EarthCache sites are in development for the Nevada Bureau of Mining and Geology website to provide information about the geology and Quaternary history of popular localities in the study area. Additionally, mapping and all other results are provided to the USDA-Forest Service, the Bureau of Land Management, and the National Park Service, which manage nearly all of the proposed study areas.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。美国西部更新世冰川记录的最新进展揭示了北方、中部、南部落基山脉和中部科罗拉多高原之间末次冰期-间冰期过渡（GIT;时间~17-10 ka）开始时的空间变异。这种变化可能反映了这些地区之间的降水差异，这是由于极地急流和伴随而来的风暴路径的位置发生变化造成的，也可能反映了大盆地洪积湖作为顺风山脉水分来源的重要性。在确定大盆地中北部冰川和湖泊波动的范围、时间和年表方面，该项目填补了美国西部冰川和古气候历史理解方面的一个广泛的空间空白，并为用于验证区域气候模型的气候记录提供了急需的补充。智力优势：大盆地中北部的许多山脉和山间山谷包含了大量的冰川和洪积湖波动的证据。然而，在这一过渡期间，冰川和湖泊对气候变化的反应的时间在这一地区几乎是未知的，在这一深刻的气候变化期间，温度和/或降水变化的性质知之甚少。利用这一地区的冰川和洪积湖记录来推断晚更新世的气候变化是当前人们非常感兴趣的，原因有几个。首先，大盆地的位置，位于美国西部内陆地区古老的冰川和洪积湖地区的中心，为研究气候敏感的小型冰川和湖泊对与北美冰盖退缩和伴随的区域尺度大气环流重组有关的气候变化的反应提供了巨大的潜力。其次，冰川和洪积湖沉积物的良好保存为宇宙成因地表暴露测年和光释光测年提供了理想的目标。最后，在最后一次GIT期间，山地冰川与封闭盆地洪积湖的接近提供了一种罕见的环境，其中冰川和湖泊质量平衡的联合数值模拟可用于设定古温度和降水的狭窄限制。更广泛的影响：这项研究是由来自两个主要的本科院校的教师进行的，现场和分析工作的各个方面都得到了来自Middlebury College和SUNY Geneseo的学生研究人员的帮助。通过这个项目制作的地图由内华达州采矿和地质局出版，使这些受欢迎地区的冰川历史可供娱乐用户使用。地球缓存网站正在为内华达州矿业和地质局网站开发，以提供有关研究地区流行地点的地质和第四纪历史的信息。此外，地图和所有其他结果提供给美国农业部林业局，土地管理局和国家公园服务，管理几乎所有的拟议研究领域。