| Rock glaciers are important, but understudied, water reservoirs in semi-arid mountain ranges.
Here we investigate the hydrologic significance of rock glaciers in Idaho's semi-arid Lost River
and Pioneer ranges. Central to this study is an extensive examination of rock glacier hydrological
characteristics, including discharge, temperature, chemistry, and isotopic signatures, across
different sites. A detailed analysis conducted from June to September 2023 across seven rock
glacier streams revealed consistent patterns: rock glacier streams maintain a stable discharge and
exhibit cooler temperatures (<5 °C) compared to non-rock glacier fed streams. Isotopic analyses
suggest that seasonal precipitation dominates water inputs across rock glaciers (d18O: -19 to
-17‰), with minimal evidence of contributions from aged ice, highlighting the complex behavior
of rock glaciers and their probable interannual variability. Moreover, carbon analysis reveals
depleted 14C in biofilms within these streams, underscoring the potential of rock glaciers as
significant reservoirs of ancient carbon. We also identify heterogeneities in hydrologic responses
among rock glaciers that are influenced by variable morphology and topographic setting among
landforms and speculate on a sub-classification of rock glacier springs. By illuminating the
complex interplay between rock glacier structure, hydrologic function, and environmental
implications, this thesis contributes valuable insights into the resilience of alpine hydrologic
systems in the face of ongoing climatic shifts, presenting a compelling case for the broader
acknowledgment and study of rock glaciers in semi-arid regions.
Keywords: rock glaciers, alpine hydrology, water resources, climate change, semi-arid
mountains, hydrograph, stable isotope geochemistry, hydrochemistry, carbon analysi |