MRI: Acquisition of a Cavity Ring-Down Spectrometer for Analyzing Stable Isotopes in Water Samples at Middlebury College

这项重大研究仪器(MRI)计划奖支持购买空腔衰减式光谱仪(CRDS)，用于分析水样中氧的稳定同位素。CRDS将支持米德尔伯里学院地质学系的研究和研究培训，该学院是一家非授予博士学位的机构。这所非授予博士学位的院校的本科生将使用CRDS进行体验式学习，以获得所需的高级论文。总体而言，地质系在所有级别的班级中通常每年提供约300个座位，预计这些学生中的大多数将有机会在他们的课程和研究中使用这种仪器。CRDS还将为来自周边机构的同事和学生提供服务，这些学生将被邀请来米德尔伯里进行分析，作为他们自己研究的一部分。因此，在米德尔伯里获得一台用于分析水同位素的CRDS将为该地区的本科生提供大量的学习机会和实践研究培训。该仪器将被广泛用于地质系的Jeffrey Munroe博士和Peter Ryan博士的研究计划。将由研究与开发中心推动的研究包括：调查记录于2010年1月31日的全新世古气候；多年生洞穴冰沉积的稳定氧和同位素；研究岩石冰川作为高山地貌地表水资源的作用；岩溶作用；有害化合物在裂隙地下水含水层中的运移和去向研究。门罗正在积极研究多年生洞穴冰沉积的稳定同位素组成和冰川化学，以编制全新世古气候记录，正在调查岩石冰川作为高山地貌地表水来源的意义，以及常年冰融化对岩石冰川流出的贡献，并正在努力根据洞穴中的稳定同位素建立长期的古气候记录。正确解释这些记录需要关于现代降水的稳定同位素组成的信息，并收集了洞穴中具有洞穴洞穴的滴水。CRDS将用于分析最近部署的自动滴水采样器采集的水样。瑞安是一名低温地球化学家，他将使用该仪器对佛蒙特州含水层的补给、流动和排放进行各种研究，因为它与透射率和成分有关。Ryan和本科生的合作者调查了裂隙岩石含水层中地质成因砷的来源，评估了富含铀的碳酸盐含水层中的非均质性，并考虑了农业和工业污染物的迁移和去向。购买CRDS将是所有这些项目向前迈出的重要一步，允许测量水中的稳定同位素，并促进将其用作地下水流动的示踪剂。这一奖励反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Major Research Instrumentation (MRI) Program award supports acquisition of a cavity ring-down spectrometer (CRDS) for analysis of stable isotopes of oxygen in water samples. The CRDS will support research and research training in the Geology Department at Middlebury College, a non-Ph.D. granting institution. Undergraduate students at this non-Ph.D.-granting institution will be engaged in experiential learning using the CRDS for required senior theses. In total, the Geology Department typically offers ~300 seats/year in classes at all levels, and it is expected that the majority of these students will have the opportunity to use this instrument during their coursework and research. The CRDS will also serve colleagues and their students from surrounding institutions who will be invited to come to Middlebury to make analyses as part of their own research. Acquisition of a CRDS for analyzing water isotopes at Middlebury will, therefore, catalyze significant learning opportunities and hands-on research training for undergraduate students in this region.The instrument will be used extensively in the research programs of Drs. Jeffrey Munroe and Peter Ryan in the Department of Geology. Research to be facilitated by the CRDS will include: investigations of Holocene paleoclimate as recorded in in the stable oxygen and isotopes of perennial cave ice deposits; studies of rock glaciers as surface water resources in alpine landscapes; karst processes; and studies of the transport and fate of deleterious compounds in fractured groundwater aquifers. Munroe is actively studying the stable isotopic composition and glaciochemistry of perennial cave ice deposits in order to develop Holocene paleoclimate records, is investigating the significance of rock glaciers as sources of surface water in alpine landscapes, and the contribution of melting perennial ice to rock glacier outflow, and is working to develop a long-term paleoclimate records from stable isotopes in cave speleothems. Properly interpreting these records requires information about the stable isotopic composition of modern precipitation and dripwater in the caves with the speleothems were collected. The CRDS will be used in analyzing water samples collected with a recently deployed automatic drip water sampler. Ryan is low-temperature geochemist who will use the instrument in a variety of studies of aquifer recharge, flow and discharge in Vermont, as it relates to transmissivity and composition. Ryan and undergraduate student collaborators have investigated the sources of geogenic arsenic in fractured rock aquifers, evaluated heterogeneity in a uranium-rich carbonate aquifer, and considered the transport and fate of agricultural and industrial contaminants. Acquisition of a CRDS will be a major step forward for all of these projects, allowing measurements of stable isotopes in water and facilitating their use as tracers of groundwater flow.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.