EGU2020-11001
https://doi.org/10.5194/egusphere-egu2020-11001
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Volcanic Jet Noise from the Kilauea Fissure 8 Lava Fountain

Julia Gestrich1, David Fee1, John Lyons2, Matthew Patrick3, Carolyn Parcheta3, Ulrich Kueppers4, and Valeria Cigala4
Julia Gestrich et al.
  • 1Alaska Volcano Observatory, University of Alaska Fairbanks, Fairbanks, United States of America (jegestrich@alaska.edu)
  • 2Alaska Volcano Observatory, U.S. Geological Survey, Anchorage, United States of America
  • 3Hawaiian Volcano Observatory, U.S. Geological Survey, Hilo, United States of America
  • 4Department of Earth and Environmental Sciences, Ludwig-Maximilians-University, Munich, Germany

Seismic and acoustic signals are important for remote real time and post-eruption analysis of volcanic eruptions. To properly interpret these signals it is critical to connect their characteristics with eruption parameters. In this study, we present an analysis of the infrasound emissions by the sustained lava fountain at Fissure 8 during the 2018 eruption of Kilauea Volcano, Hawaii. This eruption was one of the largest and most destructive events in Hawaii’s historic times. Large (35.5 km2) lava flows covered much of the Lower East Rift Zone (LERZ) and destroyed property and infrastructure. This activity was dominated by high lava effusion rates at Fissure 8 and lava fountains up to 80 m tall. The energetic output of gas and lava produced sustained, broadband acoustic waves which were recorded by a four-element infrasound array deployed 0.6 km northwest of the fountain. The spectrum of the infrasound is similar to that of man-made jets and is termed volcanic jet noise. We compare the spectrum of the recorded infrasound signal with models developed for man-made jets such as rockets and jet engines. These models predict different spectral shapes for fine scale turbulence (FST), produced by incoherent movement of the gases, and large scale turbulence (LST), produced by coherent instability waves. The dominance of one or the other turbulent noise source is highly directional. We compare the infrasonic signals with observations of fountain properties, such as pyroclast velocity and height, to help understand the jet noise signals and determine quantitative fountain properties from the infrasound. The results of this work will contribute to the understanding of the physics of lava fountain sound generation, its dependence on eruption parameters, and ultimately provide a tool for rapid assessment of eruption style and dynamics.

How to cite: Gestrich, J., Fee, D., Lyons, J., Patrick, M., Parcheta, C., Kueppers, U., and Cigala, V.: Volcanic Jet Noise from the Kilauea Fissure 8 Lava Fountain, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11001, https://doi.org/10.5194/egusphere-egu2020-11001, 2020.

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