HR: 1340h
AN: V53B-1331    [Abstracts]
TI: Airborne CO₂ and H₂S Measurements at Hot Spring Basin, Yellowstone National Park
AU: * McGee, K A
EM: kenmcgee@usgs.gov
AF: U.S. Geological Survey, Cascades Volcano Observatory, 1300 SE Cardinal Ct., #100, Vancouver, WA 98683, United States
AU: Doukas, M P
EM: mdoukas@usgs.gov
AF: U.S. Geological Survey, Cascades Volcano Observatory, 1300 SE Cardinal Ct., #100, Vancouver, WA 98683, United States
AU: Werner, C A
EM: cwerner@usgs.gov
AF: U.S. Geological Survey, Cascades Volcano Observatory, 1300 SE Cardinal Ct., #100, Vancouver, WA 98683, United States
AB: Gas emission-rate measurements at thermal areas located in remote regions with difficult ground access and little topographic relief pose a special challenge to those attempting to assess volcanic hazards in those areas. Several attempts have been made to measure gas emission rates from geyser basins, thermal areas and discrete large fumaroles at Yellowstone National Park through the use of fixed-wing aircraft with an on-board measurement system similar to that employed elsewhere at large stratovolcanoes. Despite minimum flight elevation restrictions and relatively flat terrain that often make access to the lowest margins of the plume difficult in these areas, we have successfully measured plumes of CO₂ and H₂S at several such areas and features at Yellowstone. We report here the results of a series of airborne measurements on 7 Jun 2006 at Hot Spring Basin (HSB), a remote vapor-dominated hydrothermal system just outside the northeast margin of Yellowstone caldera containing multiple gas vents. Using a LI-COR infrared spectrometer and Interscan electrochemical detector system, we detected a 3-km-wide plume approximately 2 km downwind from HSB. Several airborne traverses through a vertical slice of the plume allowed us to construct a cross-section of the plume and yielded emission rates of 170 metric tonnes per day (t/d) for CO₂ and 2 t/d for H₂S, similar to rates measured at Mt. Baker, WA (USA) in September 2000. However, an August 2006 ground-based study of emissions from HSB yielded higher emission rates for both CO₂ and H₂S (Werner et al., this session), suggesting that not all of the diffuse emissions are reflected in the airborne measurement. Although a complete inventory of plume emission rates from the majority of degassing sources in Yellowstone National Park is not yet complete, HSB appears to be a smaller gas emitter than some of the other sources in the Park (e.g., Norris Geyser Basin, Brimstone Basin, Mud Volcano, Grand Prismatic Spring and Mammoth Hot Springs).
DE: 8400 VOLCANOLOGY
DE: 8419 Volcano monitoring (7280)
DE: 8424 Hydrothermal systems (0450, 1034, 3017, 3616, 4832, 8135)
DE: 8430 Volcanic gases
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting