Collaborative Research: A place-based, student-led research project in the Pioneer Mountains, Montana: an investigation of very dry, alpine glaciation proximal to the Laurentide Ic

该项目将结合当地地球科学学生和体验式的、基于地点的教育方法，重建蒙大拿州西南部先锋山脉的冰川历史。这个项目将使蒙大拿州西部大学第一代代表性不足的大学生沉浸在气候研究中。学生们将与美国国家科学基金会支持的佛蒙特大学社区宇宙成因设施合作，调查该地区的冰川历史。研究人员将验证这样一种假设，即位于大冰原附近、经历低温和异常低降水的冰川，可能比劳伦泰德（即加拿大）冰原的最大值（约21000年前）早得多地达到当地冰范围的最大值。他们将通过对先锋山脉的冰川冰碛进行采样和定年来实现这一目标，由于大陆分水岭沿线的山脉阻挡，该山脉今天的降水量非常低。先锋山的冰川冰碛序列可能为山地冰川对地球长期轨道波动和伴随的气候变化的响应机制提供新的认识。这个基于地点的研究项目将为本科生提供一个身临其境的机会，让他们更好地了解自己州的景观，形成它们的地貌过程，以及它们提供的重要气候信息，其中许多学生来自蒙大拿州的农村。本研究将深入了解末次冰期期间劳伦泰德冰原（LIS）附近大陆气候区冰川的前进和后退，该区域位于一个异常干燥的山脉，冰川年代学尚未研究过。先锋山脉是蒙大拿州西部少数花岗岩覆盖的山脉之一，因此可以使用石英中的10Be测定宇宙核素暴露年龄，从而产生该地区的第一个冰碛年代学。研究人员将测试在美国东部和西北发现的最大冰时间的差异是由于区域气候差异造成的，比如由美国的存在驱动的反气旋风模式，还是非气候因素（例如，低气压和响应时间）。这样的大气压力系统会使西风的海洋水汽流偏离北落基山脉，因此先锋队的冰川极大期可能先于LIS极大期和前面提到的冰川系统。这项工作的结果将促进对极端干燥和极冷条件下温度依赖冰川的理解，为了解世界上最冷、最干燥地区的当前冰川如何应对现代气候变暖提供见解。该项目由地貌和土地利用动力学计划（GLD）和促进竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will incorporate local geoscience students and an experiential, place-based educational approach to reconstruct the glacial history of the Pioneer Mountains in southwest Montana. This project will immerse first-generation, under-represented college students at the University of Montana Western in climate research. Students will investigate the region’s glacial history in collaboration with the NSF-supported Community Cosmogenic Facility at University of Vermont. The investigators will test the hypothesis that glaciers, located near large ice sheets and experience both cold temperatures and exceptionally low precipitation, may have reached local ice extent maximums considerably earlier than the Laurentide (i.e., Canadian) Ice Sheet maximum (~21,000 years ago). They will do this by sampling and dating glacier moraines in the Pioneer Mountains, which today have very low precipitation due to blocking by ranges along the Continental Divide. Glacier moraine sequences from the Pioneer Mountains may shed new understanding into the mechanisms by which mountain glaciers respond to Earth’s long-term orbital fluctuations and concomitant climatic changes. This place-based research project will provide the undergraduate students, many of whom are from rural Montana, with an immersive opportunity to better understand their own states’ landscapes, the geomorphic processes that formed them, and the important climatic information they provide.This research will provide insight into glacier advance and retreat during the last glaciation in continental climatic regions that were proximal to the Laurentide Ice Sheet (LIS), in an exceptionally dry mountain range where the glacial chronology has not been studied. The Pioneer Mountains are one of the few ranges in western Montana underlain by granite, making it feasible to use 10Be in quartz for cosmogenic nuclide exposure ages and thus produce the first moraine chronologies for the region. The investigators will test whether the differences in maximum-ice times found in eastern ID and northwestern WY are due to regional climatic contrasts, such as anticyclonic wind patterns driven by the presence of the LIS or non-climatic factors (e.g., hypsometry and response time). Such atmospheric pressure systems would deflect westerly maritime moisture flux away from the northern Rocky Mountains as the LIS developed, and therefore the glacier maxima in the Pioneers may precede the LIS maxima and the aforementioned glacier systems. Results from this work will advance the understanding of temperature-dependent glaciers under extremely dry and very cold conditions, providing insight about how current glaciers in the coldest, driest regions of the world may respond to modern climate warming. This project is jointly funded by the Geomorphology and Land-use Dynamics Program (GLD) and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.