EVALUATING THE PHYSIOGRAPHIC AND CLIMATIC CONTROLS ON ROCK GLACIERS AND PROTALUS RAMPARTS IN THE DRY ANDES, SAN JUAN, ARGENTINA

Recent environmental legislation in Argentina protects ground ice, including that in rock glaciers and protalus ramparts, as important sources of water reserves in the Dry Andes. However, the true extent of ground ice coverage – and therefore its impact on regional hydrology – is not well known in this remote and little-studied terrain. This study investigates the physiographic and climatic factors controlling the distribution of rock glaciers and protalus ramparts using a digital inventory from two different locations of the Dry Andes in the San Juan Province, Argentina. Principal components analysis of the inventory data indicates that south and west-trending slopes favor the formation of rock glaciers, whereas north and east-trending slopes favor the formation of protalus ramparts. These results, when coupled with other data, indicate that protalus ramparts and rock glaciers form in unique physiographic settings where slope, elevation, and solar radiation are the primary controls on their presence/absence. Our methods and results can be applied to other areas in the Dry Andes to identify analogous conditions aiding land-use and environmental protection decisions.