• Holocene Hydroclimate of Alaska from Isotope Studies of Paleoenvironmental Water
    • Lesleigh Anderson (USGS)
    • October 04, 2019

The importance of a changing climate on Alaskan water and ecosystems underlies the need for long-term perspectives available from the recent geologic past. The proxy explored here is the stable isotopic signature of paleoenvironmental water (oxygen and hydrogen) from the northern interior and south central regions of Alaska contained within geologic archives from lakes, peatlands, trees (fossil and living), and permafrost. We can work towards constraining paleoenvironmental interpretations of the water isotope proxy data with investigations of modern and historic water isotopes (e.g., accumulated snowpack, precipitation, groundwater, streams, rivers and lakes) and by comparisons with additional paleo proxy sensors (e.g., pollen, macrofossils, carbon isotopes, sedimentology).Terrestrial multi-proxy records have long provided abundant evidence for late Quaternary paleohydrologic change and demonstrated significant variations in effective moisture balance (precipitation -v- evaporation).

In this talk we will also discuss additional aspects of the hydrologic cycle, such as shifts in seasonal atmospheric circulation patterns, sub-tropical teleconnections, and topographic effects, which together have complex regional influences on the balance of seasonal precipitation (snow -v- rain), particularly with respect to mountain range orientation. A better understanding of these dynamics also has important implications for the cryosphere, including thermokarst and permafrost in peatlands. In addition to long-term context and baselines, these studies provide insights into the environmental processes and mechanisms that are needed to develop a deeper understanding of the regional patterns of ongoing change.

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