"Home to more than 10,000 thermal features, Yellowstone has experienced over 20 large hydrothermal explosions producing craters from 100 to over 2500 meters in diameter during the past 16,000 years. Using new mapping, sampling, and analysis techniques, this volume documents a broad spectrum of ages and geologic settings for these events and considers additional processes and alternative triggering mechanisms that have not been explored in previous studies. Although large hydrothermal explosions are rare on the human time scale, the potential for future explosions in Yellowstone is not insignificant, and events large enough to create a 100-m-wide crater might be expected every 200 years. This work presents information useful for determining the timing, distribution, and possible causes of these events in Yellowstone, which will aid in the planning of monitoring strategies and the anticipation of hydrothermal explosions."--Publisher's description.

This dissertation investigated the role of biology in several biogeochemical cycles in acid sulfate chloride (ASC) geothermal springs in Yellowstone National Park (YNP). Elemental sulfur (S°) is associated with many geothermal springs, yet little is known about the organisms involved in its cycling. The aqueous and solid phase geochemistry near the source of Dragon Spring, an ASC spring in the Norris Geyser Basin (NGB) of YNP, was used to guide the enrichment and isolation of two novel S°-reducing Crenarchaeota affiliated with the order Desulfurococcales. Both isolates are chemoorganotrophs, dependent on complex peptide-containing carbon sources, S°, and anaerobic conditions for respiration-dependent growth. Physiological characterization suggests the isolates are adapted to the physicochemical conditions of Dragon Spring which is supported by quantitative PCR analysis which indicates that the isolates represent a significant fraction of the microbial community associated with S° precipitates in several ASC geothermal springs in the NGB in YNP.

Learn about Yellowstone National Park's history and varied attractions, including Old Faithful, Lower Geyser Basin, and Tower Fall, as well as its resident wildlife.