Acquisition of an Automated Laser Diffraction Particle Size Analyzer at the University of Massachusetts

这笔拨款支持收购激光衍射粒度分析仪与自动样品制备和导入设备。该仪器将支持马萨诸塞大学阿默斯特分校的教职员工和学生的研究，这些研究需要确定沉积物和土壤中的细粒粒度分布。粒度分析是支持沉积学、自然灾害学、古气候学、地貌学和水文学研究的基本工具。研究极端事件期间河流和河口的泥沙运移、北极古气候调查和断裂带材料力学特性将得到支持。学生将接受仪器程序方面的培训，该仪器将服务于新英格兰地区的机构。此次收购还将支持教师拓展工作，让地区K-12和社区大学的学生参与与社会相关的古环境研究。这种支持与NSF促进科学进步和促进国家健康、繁荣和福利的使命是一致的，因为有针对性的研究旨在了解影响美国东北部的历史飓风记录，记录在陆地和海洋沉积记录中，研究地球气候动力学记录在湖泊沉积物中，以及收购对培训下一代科学劳动力的影响。关于极端洪水期间流体和沉积物输运的基本机制仍然存在很大的不确定性。为了填补这一知识空白，马萨诸塞大学阿默斯特分校的沉积学实验室和弗吉尼亚理工大学的同事们目前正在利用历史洪水的沉积模式来验证和提供极端水流下沉积动力学的数值模拟。泥沙粒度分布？后屏障沼泽和池塘中的S可以变化3个数量级，从海岸粗糙的海滩砂和砾石到向陆地延伸的细粒泥幔。绘制这些沉积物的空间趋势有助于了解极端洪水事件期间沉积物运移的物理特性。激光粒度分析仪还将用于识别嵌入在细粒度湖泊和泻湖沉积物中的粗粒度风暴沉积物，以进一步扩展我们对史前飓风事件的认识，从而更好地了解飓风危害的可能性。粒度分析仪还将通过检查湖泊沉积物粒度的古记录（作为冰川前进和后退的代表）来帮助研究高纬度冰川历史。

This grant supports acquisition of a laser diffraction particle size analyzer with automated sample preparation and introduction devices. The instrument will support faculty and student research at the University of Massachusetts Amherst that requires determination of fine grained particle size distributions in sediments and soils. Grain size analysis is a fundamental tool supporting research in sedimentology, natural hazards, paleoclimatology, geomorphology, and hydrology. Studies of sediment transport in rivers and estuaries during extreme events, Arctic paleoclimate investigations, and fault zone material mechanical properties will be supported by the acquisition. Students will be trained in instrumental procedures and the instrument will serve regional institutions in New England. The acquisition will also support faculty outreach efforts to engage regional K-12 and community college students in societally relevant paleoenvironmental research. This support is congruent with NSF's mission of promoting the progress of science and advancing the national health, prosperity and welfare given the relevance of targeted research aimed at understanding records of historical hurricanes affecting the U.S. Northeast as recorded in the terrestrial and marine sedimentary records, studies of Earth's climate dynamics as recorded in lake sediments and the impact of the acquisition on training the next generation scientific workforce.Significant uncertainty remains regarding the fundamental mechanisms of fluid and sediment transport during extreme flooding. To fill this knowledge gap, the sedimentology lab at the University of Massachusetts Amherst and colleagues at Virginia Tech are currently using patterns in deposition from historical floods to validate and inform numerical simulations of sediment dynamics under extreme flows. Grain size distribution of sediment?s in back barrier marshes and ponds can vary by 3 orders of magnitude, from coarse beach-derived sand and gravel at the coast to fine-grained mud drapes at their landward extents. Mapping spatial trends in these deposits assist in understanding the physics of sediment transport during extreme flood events. The laser particle size analyzer will also be used to identify coarse-grained storm deposits embedded within fine-grained lake and lagoon sediments to further extend our knowledge of pre-historic hurricane events and therefore better understand the probability of hurricane hazards. The particle size analyzer will also aid in studies of high latitude glacial history by examining the paleorecords of lake sediment grain size as a proxy of glacial advance and retreat.