Geophysical Investigations of Geyser Structure and Eruption Dynamics at Spouter, Geyser, Yellowstone National Park

Download or read book Geophysical Investigations of Geyser Structure and Eruption Dynamics at Spouter, Geyser, Yellowstone National Park written by Daniel A. Ciraula and published by . This book was released on 2021 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yellowstone National Park is home to roughly 500 geysers, making it the most concentrated geyser field in the world and the perfect environment to study these features. Recent studies explore the mechanics of geyser eruptions through laboratory models, focusing on a “bubble trap” hypothesis of eruption initiation where trapped vapors in a laterally offset cavity over-pressurize the system and initiate an eruption event. However, the subsurface geometry of geysers remains uncertain, and models are constructed with simplistic geometries. In this study, I present results from active geophysical surveys to image subsurface geyser structure and constrain the geophysical response of the hydrothermal reservoir of Spouter Geyser, Yellowstone National Park. Furthermore, I build on the structural findings and explore geyser eruption dynamics by measuring the hydrothermal fluid and vapor flux through the structure during the geyser eruption and recharge phases with time-lapse geophysical methods. Through the geophysical investigation, I interpret the shallow geyser conduit structures to ~15 m depth, connecting the geyser surface vents to a low porosity hydrothermal reservoir structure approximately 50 m in diameter and located northeast of Spouter Geyser at depths greater than 15 m. The results of the time-lapse geophysics support the bubble trap model of eruption initiation at Spouter Geyser by identifying changes in water content through the eruption and recharge phases, vapor buildup at the top of the laterally offset hydrothermal reservoir during the recharge phase, and a “flash eruption zone” within the hydrothermal reservoir where the superheated fluids first vaporize.