FRESHWATER RESOURCE EVALUATION OF THE UPPER CAMP BIRD III ROCK GLACIER, SAN JUAN MOUNTAINS, COLORADO

Decreased rainfall, reduced snowpack, shorter snow seasons, and changes in timing, frequency, and intensity of precipitation events are expected as a result of climatic variability in some areas of the world, whereas other regions will suffer from the opposite effects. In the first scenario, the window for recharge for three water sources in periglacial environments: glaciers, aquifers, and rock glaciers, could decrease.

Rock glaciers occur in permafrost areas and are comprised of rock fragments, fine sediments, and ice. Internally, they can be ice-cemented or ice-cored. Externally, a mantle of rubble insulates and prevents their response to short-term temperature increases.

Rock glaciers are alpine aquifers because they constitute a highly porous reservoir that can store water. There are complex relationships between inputs and outputs of ground and surface water, as well as phase changes (solid-liquid) that complicate the pathways for water flow within rock glaciers. Heterogeneity of materials, as well as the poor sorting distinctive of the debris conforming them, add complexity to the determination of the hydrological characteristics of rock glaciers.

The proposed research will characterize the internal structure, as well as estimate the volume of ice stored within a rock glacier to evaluate its potential for freshwater resources. The rock glacier of interest is located on the third level of Camp Bird Mine (CBM) in Ouray, Colorado.

Geophysical methods will be used to determine the subsurface characteristics of the CBM III rock glacier. Information from the geophysical surveys will complement the geologic and geomorphological mapping carried out using traditional methods as well as remote sensing techniques.

Knowing the internal makeup of the rock glacier is integral to determine the hydrological properties of its building materials and will provide the necessary information to create a hydrogeological model of the CBM III rock glacier. Furthermore, we plan to capture rainwater and compare stream outputs of the rock glacier using O and H stable isotope composition of surface and groundwater to identify possible recharge zones. Water characterization will aid in the evaluation of the rock glacier as a potential source of freshwater.