MRI: Integrated Sampling and Analysis Platform for the Investigation of Lake Geochemistry Over a Range of Temporal and Spatial Scales

[01:15 . 900]该主要研究仪器（MRI）奖将使研究人员能够组装一个具有成本效益和技术复杂的仪器平台，用于协调湖泊生物地球化学调查。该平台位于Godfrey Marine的一艘浮船上，配备了四种基于fia的在线仪器（Fe、H2O2和营养分析）、CTD（温度、深度、电导率、pH、eH、O2、荧光）、GPS导航和振动检测系统。该仪器提供了测量水柱和沉积物中多种地球化学参数的能力，测量范围包括时间尺度（秒到世纪）和空间尺度（厘米到公里）。实地工作将集中在贝尔格莱德湖，在那里缅因两种一般类型的湖泊并存，可以进行比较。综合采样分析平台将用于研究这些湖泊中铁、H2O2、NO3-和PO43-的时空分布。这项调查的关键是估计地下水的营养输入和营养的历史埋藏，因为它与内部营养负荷有关。系统中的流体流动将使用Visual MODFLOW软件进行建模，该软件根据季节和流域尺度上的实际物理和化学流体流动进行校准。利用该平台将获得流域沉积物的振动孔。使用标准的沉积学技术，将开发从海洋到淡水条件过渡的详细历史记录。将绘制和评估反映长期时空变化的盆地地层元素分析。利用这些数据，再加上每日、每周、每月和每年获得的类似化学数据，湖泊地球化学动力学将在几个尺度上进行评估。学生的参与是本研究不可分割的一部分。学生研究助理将在夏季期间帮助项目的各个方面。此外，每年约有40名学生将积极使用集成采样和分析平台，作为两门地质学和两门化学课程的一部分。在一定的空间和时间范围内的数据分析将被用来建立研究项目之间的联系。这样的研究工作将提供学生通常认为不相关的学科之间的联系，帮助他们认识到地球过程是系统过程

0115900KingThis Major Research Instrumentation (MRI) award will allow the investigators to assemble a cost-effective and technically sophisticated instrument platform for coordinated biogeochemical investigations in lakes. The platform is based in a Godfrey Marine pontoon boat equipped with: four on-line FIA-based instruments (Fe, H2O2, and nutrient analysis), CTD (temperature, depth, conductivity, pH, eH, O2, fluorescence), GPS navigation, and a vibracoring system. This instrument provides the capability to measure multiple geochemical parameters in the water column and sediments over a range of scales - both temporal (seconds to centuries) and spatial (cm to km). Fieldwork will be concentrated in the Belgrade Lakes, where both general types of Maine lakes coexist and can be compared. The integrated sampling and analysis platform will be used to investigate the spatial and temporal distribution of iron, H2O2,, NO3-, and PO43- in these lakes. Critical to this investigation is an estimate of nutrient inputs from ground waters and historical burial of nutrients as it pertains to internal nutrient loading. Fluid flow through the system will be modeled using Visual MODFLOW software calibrated against actual physical and chemical fluid flow over seasonal, and watershed scales. Vibracores of watershed sediments will be obtained using the platform. Using standard sedimentological techniques a detailed historical record of the transition from marine to freshwater conditions will be developed. Stratigraphic elemental analyses across the basins, reflecting long-term temporal and spatial changes, will be mapped and assessed. Using these data, coupled with similar chemical data obtained on a daily, weekly, monthly, and yearly basis, lake geochemical dynamics will be evaluated over several scales.Student participation is an integral part of this study. Student research assistants will help with all aspects of the project during the summer months. In addition, approximately 40 students a year will actively use the integrated sampling and analysis platform as part of two Geology and two Chemistry courses. Analysis of data over a range of space and time will be used to draw connections between the research projects. Such research efforts will provide the linkages between what students generally consider unrelated disciplines, helping them to recognize that Earth processes are system processes.***