Skip to content

The first instrumentally detected hydrothermal explosion in Yellowstone National Park

Michael P. Poland1, Alex M. Iezzi1, Jamie Farrell2, R. Greg Vaughan3

  • Affiliations: 1U.S. Geological Survey, Cascades Volcano Observatory, Vancouver, WA, USA; 2Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA; 3U.S. Geological Survey, Astrogeology Science Center, Flagstaff, AZ, USA 

  • Presentation type: Poster

  • Presentation time: Monday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 231

  • Programme No: 2.4.20

  • Theme 2 > Session 4

Abstract

Hydrothermal explosions are an underappreciated hazard in Yellowstone National Park, and their impact and importance were demonstrated by the well-observed event on July 23, 2024, at Biscuit Basin. To monitor hydrothermal activity, the Yellowstone Volcano Observatory is installing monitoring stations in geyser basins, with sensors including broadband seismic, GNSS, meteorological, and infrasound. The first such station was installed in Norris Geyser Basin in September 2023. Infrasound array data from that site recorded an impulsive signal coming from the northeast on April 15 at 20:56 UTC (14:56 local time). Data from nearby broadband seismometers are indicative of a ground-coupled airwave, suggesting that a small explosion had occurred. High-resolution satellite imagery from the explosion source direction indicated a drop in the level of water in hot springs between April 2 and 21, and field observations in May identified the presence of newly disrupted ground, including a crater 3 meters in diameter surrounded by clasts of silica sinter. Recognition of the explosion confirms the utility of hydrothermal monitoring and argues for expansion of the network at Norris Geyser Basin and in other thermal areas to better characterize the process, assess any precursors that might aid with forecasting, and detect future explosions to establish their frequency and patterns of occurrence. The July 23, 2024, explosion at Biscuit Basin was only weakly detected in retrospect at a broadband seismic station a few kilometers away, emphasizing the importance of both local infrasound and seismic monitoring.