Collaborative Research: Using a Combined Basin Analysis, Isotopic, and Modeling Approach to Reconstruct the LGM through Early Holocene Hydroclimate for Glacial Lake Mojave.

水是加州最关键、最不可预测的资源。作为一个以农业为主的经济体，CA的社会经济成功和可持续性与水资源的可获得性密切相关。作为美国最大的州经济，加州的健康对美国的健康至关重要。为了了解现代和未来的水资源可获得性，科学家们着眼于过去来预测未来--这是一个被称为古气候学的研究领域。像莫哈韦沙漠这样的干旱环境对水的可获得性特别敏感。因此，干旱环境是研究水循环过去变化的绝佳场所。该项目将以银湖(CA)为重点，结合地质学、水文学和建模方法，研究地球历史上最近的、气候最活跃的时期之一--从最后一次冰川盛期(距今约24,000年)到全新世早期(距今约8,000年)--水资源可获得性变化的幅度、幅度和频率。最重要的是，我们的新的跨学科方法将使我们能够量化过去水可获得性的变化，并评估导致这些变化的气候驱动因素。加州州立大学富勒顿分校和圣地亚哥峡谷学院(均为西班牙裔服务机构)将与布朗大学(一所主要的研究活跃大学)合作，为总共15名受资助的学生和1名博士后创造多样化的教育和研究体验。这种多院校合作为两年制大学生转学四年制大学提供了一条明确的途径，并在代表性不足的群体中建立了积极的科学认同感和归属感。这项研究将使用盆地分析(即从中心到海岸)、同位素和建模相结合的方法来重建最小湖泊深度、最小湖泊体积和冰川晚期至全新世早期必要的水文气候条件的定量记录，以填充冰川莫哈韦湖表面上的末端盆地-银湖盆地。现有和新的海滩或近岸地貌地点将使用基于无人机的运动结构摄影测量来识别和表征。这些海岸数据及其各自的年龄将与确定日期和分析的沉积物岩心结合起来，以量化24-8ka期间最小湖泊深度的变化，从而量化湖泊体积的变化。结合这些地质数据，项目组将应用氧同位素约束的湖泊系统非稳定状态水文模型，以量化在冰川晚期至全新世早期填充和维持银湖所需的必要条件。最后，这项工作的结果将与各种气候强迫相比较，以评估大盆地南部水文气候变化的主要驱动因素。该奖项由地球科学部和大气和地球空间科学部通过古气候展望计划共同资助，并增加了各种机构的研究能力、能力和基础设施，如地球观测组织拥抱DCL所概述的。该奖项反映了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。

Water is California’s (CA) most critical and unpredictable resource. As a predominantly agricultural economy, CA’s socioeconomic success and sustainability are closely tied to water availability. And as the United States' largest state economy, the health of CA is important to the health of the United States. To understand modern and future water availability, scientists look to the past to inform the future – a field of study called paleoclimatology. Arid environments like the Mojave Desert are especially sensitive to water availability. As a result, arid environments are excellent sites for studying past changes in the water cycle. This project will focus on Silver Lake (CA) and combine geological, hydrological, and modeling methods to examine the amplitude, magnitude, and frequency of changes in water availability across one of the most geologically recent and climatically dynamic periods in Earth’s history – the period from the Last Glacial Maximum (ca. 24,000 years before present) to the early Holocene (8,000 years before present). Most importantly, our novel and transdisciplinary methods will allow us to quantify past changes in water availability and assess the climatic drivers that cause these changes. Cal-State Fullerton and Santiago Canyon College (both Hispanic Serving Institutions) will partner with Brown University (a major research-active university) to create a diverse educational and research experience for a total of 15 funded students and 1 post-doc. This multi-institutional collaboration provides a clear pathway for 2-year college students to transfer into 4-year universities and establishes a positive science identity and a sense of belonging in underrepresented groups. This research will use a combined basin analysis (i.e.,core-to-shore), isotopic, and modeling approach to reconstruct a quantitative record of minimum lake depth, minimum lake volume, and the requisite hydroclimatic conditions during the Late Glacial to Early Holocene necessary to fill the Silver Lake Basin, the ostensible terminal basin of Glacial Lake Mojave. Existing and new beach or near-shore geomorphic sites will be identified and characterized using UAV-based, Structure-from-Motion photogrammetry. These shore data, and their respective ages, will be coupled with dated and analyzed sediment cores to quantify changes in minimum lake depth, and thus lake volume, from 24-8 ka. Coupled with these geological data, the project team will apply oxygen isotopic constrained, non-steady state hydrologic models of the lake system to quantify the requisite conditions necessary to fill and sustain Silver Lake during the Late Glacial to Early Holocene. Finally, the results from this work will be compared to a variety of climatic forcings to evaluate the primary drivers of hydroclimatic change in the southern Great Basin. This award is co-funded by the Division of Earth Sciences and Division of Atmospheric and Geospace Sciences by way of the Paleo Perspectives on Present and Projected Climate program, and increases research capabilities, capacity and infrastructure at a wide variety of institution types, as outlined in the GEO EMBRACE DCL.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.