Doctoral Dissertation Research: A High-Resolution Record of Holocene Climate Change from Big Soda Lake, Nevada

气候变化的氧同位素记录用于量化过去的气候条件，确定过去气候变率的机制，验证过去气候的模式模拟。这项研究将开发内华达州西北部过去4000年气候变化的高分辨率同位素记录。从内华达州法伦附近的大Soda湖恢复的沉积物岩心是季节性层压的，这使得重建大盆地西部全新世气候变化的详细高分辨率记录（即年代际记录）成为可能。该湖主要由地下水提供水源；因此，动物、矿物学和地球化学的变化与气候和人类活动的变化直接相关。一个关键的问题是，与近代历史时期的记录相比，史前地下水水位的变化在多大程度上发生了变化。沉积特征，如地球化学、粒度、磁化率和有机含量将被测量，以确定区域气候变化。将通过多种方法确保准确的时间控制，包括阀（沉积物层）计数、花粉浓度的放射性碳定年、定年的麻药、非本地花粉和铅-210定年。这项研究将通过创造连续的沉积物岩心记录来填补以前研究的重要空白，从而有助于我们目前对气候变化的理解。这项亚年代际分辨率的研究将解决我们对过去气候变化区域变化的理解中的时间差距，并解决阻碍该地区湖泊研究的时间问题。研究结果将为揭示大盆地西部晚全新世气候变化的多变性提供依据。了解这个人口不断增长的旱地地区过去的气候变化，可以帮助预测未来的潜在变化，因为自然和人类活动对水平衡的变化很敏感。作为博士论文研究改进奖，该奖项将为有前途的学生提供支持，使他们能够建立强大的独立研究事业。

Oxygen isotope records of climate change are used to quantify past climatic conditions, to identify mechanisms of past climatic variability, to verify model simulations of past climate. This research will develop a high-resolution isotopic record of climate change in northwestern Nevada over the past 4000 years. Sediment cores recovered from Big Soda Lake near Fallon, Nevada are seasonally laminated which make it possible to reconstruct a detailed high-resolution record (i.e. sub-decadal) of Holocene climate change in the western part of the Great Basin. The lake is primarily fed by groundwater; therefore, changes in the fauna, mineralogy and geochemistry are directly related to changes in climate and human activity. A key question is to what extent prehistoric changes in groundwater levels compare to those recorded during recent historical times. Sedimentary characteristics such as geochemistry, grain size, magnetic susceptibility, and organic content will be measured to identify regional changes in climate. Accurate chronological control will be ensured through multiple methods including varve (sediment layer) counting, radiocarbon dates on pollen concentrations, dated tephras, non-native pollen and lead-210 dating. This research will contribute to our current understanding of climate change in through creation of continuous sediment core records that fill important gaps from previous research. This sub decadal-resolution study will resolve temporal gaps in our understanding of the regional variation of past climate change, and resolve chronological problems that have hindered previous lake studies in the region. The results will provide insight into the variability of late Holocene climate change in the western Great Basin. Understanding past climate change in this drylands region with an expanding population, can help predict potential future change where natural and human activities are sensitive to changes in the water balance.As a Doctoral Dissertation Research Improvement award, this award will provide support to enable a promising student to establish a strong independent research career.