The Importance of Debris Glaciers in Debris Glaciers in the Geomorphological and Hydrological Systems of the Santiago Mountain Range: Fundamentals and First Results
Keywords:
Rubble’s glaciers, permafrost, periglacialAbstract
The rock glaciers of the Andes of Santiago de Chile are unsuspicious, but important water resources and play a key role within the debris transport system of this semiarid high mountain area. The significance of these bodies of debris and ice within the geomorphologic and hydrologic system is shown in the case of the Casa de Piedra valley. This subcatchment of the Yeso river is situated very close to the El Yeso reservoir, which is of outstanding importance for the drinking water supply to Santiago. In the Casa de Piedra valley, recent sporadic permafrost in the form of active rock glaciers reaches down to 3000 m a.s.l. Between 3500 and 3800 m a.s.l., active rock glaciers occupy even 16% of the total debris-covered area and represent the predominant landform. Therefore discontinuous mountain permafrost has to be assumed above 3500 m a.s.l. In the study area, debris rock glaciers are observed as well as morrainic rock glaciers, the latter in lower altitudes in the neighborhood of dead ice bodies and the corresponding end morraines. The transition to the nival zone takes place around 3800 m a.s.l. at the recent equilibrium line of glaciers. In the Casa de Piedra valley, more frozen water is stored in active rock glaciers than in “true” glaciers. This situation may be assumed to be representative of many of the small catchments in the Andes of Santiago with elevations below approx. 5000 m a.s.l.
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