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《美国复苏与再投资法》（公法111-5）资助的。了解美国西部更新世冰川记录的最新发展揭示了在北部，中部，中部落基山脉和科罗拉多州中部高原的最后一次冰川间间冰河转变开始的空间变异性（GIT；时间〜17-10 ka）。这种可变性可能反映了这些区域之间由于极地喷射的位置和伴随风暴轨迹的位置的变化而引起的这些区域之间的差异，或者可能是大盆地植物湖泊作为作为下风山脉的水分来源的重要性。在确定北北中部大盆地冰川和湖泊波动的程度，时机和年表时，该项目填补了美国西部冰川和古气候历史的广泛空间差距，并为验证区域气候模型的气候记录提供了急需的补充。知识分子的优点：中北部大盆地中的许多山脉和山间山谷都包含大量冰川和Pluvial湖泊波动的证据。但是，在该区域中，冰川和湖泊对气候变化的反应几乎是未知的，并且在这一深刻的气候变化时间间隔内温度和/或降水变化的性质尚不清楚。在最新更新世期间，使用该地区的冰川和Pluvial Lake Records推断气候变化，这是当前的极大兴趣。首先，大盆地的位置是美国西部内部冰川和普鲁维亚湖地区的中心位置，为检查气候敏感，小冰川和湖泊的响应提供了重要的潜力，这些潜力与北美冰片的撤退以及伴随的伴随的伴随的气候变化以及伴随的区域尺度大气循环相关的气候变化。其次，冰川湖沉积物的出色保存为宇宙表面暴露日期和光学刺激的发光（OSL）日期提供了理想的目标。最后，在最后一个GIT期间，山地冰川靠近封闭的巴丁湖湖泊提供了一种罕见的环境，在该环境中，冰川和湖泊质量平衡的组合数值模型可用于在古温度和降水量上设置狭窄的限制。更广泛的影响：这项研究是由两个主要是本科机构的教师进行的，现场和分析工作的各个方面得到了米德尔伯里学院和纽约州立大学Geneseo的学生研究人员的帮助。通过该项目生产的地图由内华达州矿业和地质局发布，使这些流行区域的冰川历史可供休闲用户使用。内华达州采矿和地质网站的Earthcache网站正在开发，以提供有关研究区域流行地区地质和第四纪历史的信息。此外，向USDA-ForeSt服务，土地管理局和国家公园管理局提供了映射和所有其他结果，这些服务几乎管理了所有拟议的研究领域。