Collaborative Research/RUI: Assessing Multi-scale Holocene Climate Variability in Western North America Using Sediments from Lake Elsinore (Southern CA)

合作研究/RUI：利用埃尔西诺湖（加利福尼亚州南部）的沉积物评估北美西部多尺度全新世气候变化

• 批准号: 0602245
• 负责人: Steven Lund
• 金额: $ 4.79万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0602245&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Assessing; Multi

The availability and quality of freshwater in western North America is directly linked to natural climate variability. The ability to determine climate variations on relevant time scales is limited by the short duration of observational and instrumental records. The need for long, high-resolution paleoclimatological records is particularly acute in Southern California, where over 20 million people are vulnerable to climate variability. This grant will develop the first complete terrestrial Holocene climate record for southern California using sediment from Lake Elsinore and compare this record to other well-dated terrestrial and marine archives from the region. Analysis of historical data indicates that Lake Elsinore is an excellent site for recording climate variability for southern California. Preliminary research on 2 drill cores from the lake's deepest basin indicates a relatively thick (~10m/9,000 yrs - based on 21 AMS 14C dates), continuous Holocene sediment sequence with minimal evidence for sediment discontinuities. Analyses of several sedimentological parameters reveal centimeter-scale variability that is consistent between the 2 cores. This grant supports further analysis of the cored sediment using established climate-sensitive proxy methods. To date, mass magnetic susceptibility, total organic matter, and total carbonate have been analyzed at 1cm contiguous intervals for both deep basin cores. This research grant focuses on two additional analyses: grain size (a proxy for lake basin and drainage basin sediment dynamics) and d18O(calcite) and d13C(calcite) (proxies for lake hydrologic budget and lake/drainage basin productivity, respectively). In conjunction with other paleoclimate records from western North America and the Pacific Ocean, the Lake Elsinore record will be used to better describe the evolution as well as the spatial and temporal patterns of Holocene climate variability over western North America. Furthermore, this record will provide a baseline of Holocene natural climate variability from which Southern California water management organizations - whom funded the initial research - can assess present water management policies. This record will also help to assess the sensitivity of the hydrologic system to a range of climate conditions.The intellectual merit of this study will provide critical information for characterizing and understanding Holocene climate variability on a local and regional scale. This research will also help to answer several important questions regarding Holocene climate evolution and its relationship to larger-scale ocean-atmosphere dynamics. The broader impacts of this work include research experience and thesis preparation for 2 undergraduate students and 1 M.Sc. student. The results of this study will be disseminated to the citizens and managers of Lake Elsinore, Riverside County, California through an interactive web site as well as the development of a field site for use in lab classes at Cal-State Fullerton. As a RUI and Minority Serving Institute, this research will also provide research opportunities for underrepresented individuals in the sciences at CSUF. Lastly, this research will provide socially relevant insight into future water variability in western North America, a region where water resource management is critical to future socio-economic stability.

北美西部淡水的可用性和质量与自然气候变化直接相关。 确定相关时间尺度上气候变化的能力受观察和工具记录的短期限制。在南加州，对长期高分辨率的古气候记录的需求尤为严重，在南加州，超过2000万人容易受到气候变化的影响。 该赠款将使用埃尔西诺湖（Lake Elsinore）的沉积物为南加州的首个完整的全新世气候记录，并将这一记录与该地区的其他良好陆地和海洋档案馆进行比较。对历史数据的分析表明，埃尔西诺湖是记录南加州气候变化的绝佳场所。对来自湖泊最深盆地的2个钻芯的初步研究表明，相对较厚（基于21 AMS 14C日期），连续的全新世沉积物序列，具有最小的沉积物不连续性证据。对几种沉积学参数的分析表明，两大核之间一致的厘米尺度变异性。该赠款支持使用已建立的气候敏感代理方法对芯沉积物的进一步分析。迄今为止，已经以1厘米的连续间隔分析了质量磁化率，总有机物和总碳酸盐。这项研究赠款重点介绍了两个其他分析：晶粒尺寸（湖泊盆地和排水盆地沉积物动力学）和D18O（方解石）和D13C（方解石）（分别用于水文预算的代理和湖泊/排水盆地生产率）。与来自北美西部和太平洋的其他古气候记录一起，Elsinore湖的记录将用于更好地描述北美西部全新世气候变异性的演化以及空间和时间模式。此外，该记录将提供全新世自然气候变异性的基线，南加州水管理组织（资助了最初的研究）可以评估当前的水管理政策。该记录还将有助于评估水文系统对一系列气候条件的敏感性。本研究的智力优点将为表征和理解当地和区域规模上全新世气候变异性提供关键信息。这项研究还将有助于回答有关全新世气候进化及其与大规模海洋 - 大气动力学的关系的几个重要问题。这项工作的更广泛影响包括为2名本科生和1 M.Sc.的研究经验和论文准备。学生。这项研究的结果将通过互动网站以及在Cal-State Fullerton的实验室课程中开发用于加利福尼亚州河滨县的Elsinore湖的公民和经理。作为RUI和少数民族服务研究所，这项研究还将为CSUF科学中代表性不足的人提供研究机会。最后，这项研究将提供对北美西部未来水变异性的社会相关见解，在该地区，水资源管理对未来的社会经济稳定至关重要。