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

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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.