Hydrogeological and Hydrochemical Investigations in West Nymph Creek Thermal Area, Yellowstone National Park, USA
Zum Verlinken/Bookmarken: http://dx.doi.org/10.23689/fidgeo-880
Fast changing geothermal features characterize the Yellowstone National Park, USA. Highresolution aerial images were taken to map the hydrothermal study area. The combination of a digital camera and a low flying (< 100 m) helium balloon was a cost and time effective method to get a status quo of the feature’s form and size. The resulting aerial overview has a resolution of 2.5 cm and is presented in a multilayer digital atlas, providing a basis for further surveying. Ground survey included mapping and on-site hydrochemistry of 18 major hydrothermal features. Arsenic concentrations are known to be elevated in Yellowstone (1.7 ± 2 mg/L) - therefore, beside trace element analysis with ICP-AES, three techniques for As speciation were applied: HG-AAS, HPLC-ICP-MS, and on-site SPE with GF-AAS. Surprisingly low total As concentrations made an evaluation of the different methods difficult. Grouping the water samples revealed two water types: steam heated waters (type I) and waters with a deep thermal origin (type II). Thus, a known hydrogeological model (White et al. 1988) is checked for its applicability to the study area.