A Model of Water Movement in Rock Glaciers and Associated Water Characteristics

A rock glacier physically and chemically influences the water which passes through it and acts as a concentrating rather than a filtering mechanism. A model for the hydrological system of rock glaciers includes direct precipitation, runoff from adjacent slopes, ice and snow from avalanching, groundwater, and initial glacial and/or periglacial ice. The primary outputs of the hydrological system are surface runoff, subsurface discharge, subsurface seepage, sublimation, and evaporation. Four subsystems, cliff and talus, surface, subsurface, and groundwater, constitute the cascading system. The model reveals many intricate pathways through a rock glacier and the necessity for careful assessment of observed differences between the quality of water input and output. Because the nature of the internal characteristics of rock glaciers must be acquired primarily from external data, water exiting rock glacier systems was analyzed. It was noted that exiting water had higher ion concentrations than entering forms; water input had total dissolved loads ranging from 1.5 to 6.0 mg l–1, whereas outputs had total dissolved loads ranging from 8.0 to 54.0mg l–1;silica concentrations ranged from 0–0.1 mg l–1 in inputs to 1.9–6.0 mg l–1 in outputs; alkalinity values for inputs ranged from 1.3 to 2.7 mg l–1 CaCO3, whereas outputs ranged from 18.1 to 44.4 mg l–1 CaCO3; 160and total hardness values for inputs were 0.0 mg l–1 CaCO3, whereas outputs ranged between 21.0 and 50.1 mg l–1 CaCO3. Water flowing through three rock glaciers decreased in pH. Inputs into the rock glaciers had pH values ranging between 6.4 and 7.0, whereas outputs had pH values ranging between 7.2 and 8.5. Peak discharge of the three rock glaciers occurred between 0900 and 1200 hours daily, before daily maximum temperature occurred.