Alpine glacier resilience and Neoglacial fluctuations in the Teton Range, Wyoming linked to Holocene snowfall trends in the western U.S.

Abstract:

Geological evidence indicates glaciers in the western U.S. fluctuated in response to Holocene (past ~11,700 years) changes in temperature and precipitation. However, because moraine chronologies are discontinuous and skewed toward recent centuries, Holocene glacier fluctuations and their climatic drivers remain ambiguous, and future glacier changes are uncertain. Here, we construct a continuous 10,000-year record of glacier activity in the Teton Range, Wyoming, using glacial and environmental indicators in proglacial lake sediments. The spectacular geomorphology of the Teton Range has attracted scientific investigation into its glaciers for nearly a century, but like most mountain ranges in the western US, essentially nothing was known about its glacial history between the Late Glacial maximum and the recent Little Ice Age. We show that Teton glaciers persisted in some form through early Holocene warmth, likely as small debris-covered glaciers or rock glaciers. Subsequent Neoglacial ice expansion began ~6.3 ka, with two prominent glacier maxima at ~2.8 and 0.1 ka that were separated by a multi-centennial phase of ice retreat. Comparisons with sedimentary datasets contained in a nearby non-glacial lake and regional paleoclimate records suggests glacier activity was dominantly controlled by winter precipitation variability superposed on long-term Holocene temperature trends, offering key insights into western U.S. glacier resilience and vulnerability to future warming.