Why Monitor the Water Discharge from Yellowstones Rivers?
Chemical geothermometry* and the chemical composition of fluids from thermal springs and shallow drill holes document a linear relationship between the chloride concentration and fluid enthalpy. On this basis nearly all of the sampled thermal waters in Yellowstone can be related to a deep water source containing about 400 ppm chloride at an enthalpy of 1,570 J/g (about 335-340°C) (Fournier, 1989). The chloride-enthalpy relationship suggests that advective heat flux can be estimated from total chloride discharge from the park. In Yellowstone, nearly all of the chloride discharged from springs eventually enters one of the four major rivers draining Yellowstone National Park: the Yellowstone and Madison Rivers east of the continental divide, and the Snake and Fall Rivers west of the divide (map). Using the chloride-inventory method**, which corrects for background chloride (~1-2 ppm) contributed by precipitation and low-temperature rock weathering, long-term river discharge and chloride c
