Precursory Seismicity and Explosion Seismoacoustics of the Recent Phreatomagmatic Eruption of Semisopochnoi Volcano, Alaska
Description:
The main explosive phase of the ongoing phreatomagmatic eruption of Semisopochnoi volcano, Alaska began shortly after a complete upgrade of the monitoring network in 2021. The network now comprises six broadband seismometers, three broadband infrasound sensors, and two web cameras. The new network is capturing an unprecedented, high-quality record of the eruption that we are using to investigate explosion source processes and the evolving configuration and state of the shallow magmatic system throughout the eruption.
We are generating a near real-time explosion catalog through a novel implementation of the REDPy repeating event detector algorithm on the local infrasound network. We further refine the catalog through a workflow that includes a network matched filter and event locations using reverse time migration. The catalog contains over 1000 events to date, providing a rich research dataset to study the relationships between explosion earthquakes and infrasound, as well as the influence of local topography and seasonal atmospheric variability on the infrasound signals. The catalog events show a high degree of similarity in the infrasound waveforms with only one dominant family occurring since explosions began in July 2021, indicating a repeating source process. We also explore the seismicity preceding the onset of explosions and find a family of repeating long-period events that began ~1 month before the onset of explosions. We are investigating how the character of these events evolved with multiple techniques (e.g., frequency index, coda wave interferometry) to determine their source process and whether they could be used to provide early warning of impending explosive activity during future eruptions. This work highlights the potential of modern monitoring networks to produce research-grade data, even at remote volcanoes, which aids in advancing our knowledge by diversifying the types and styles of eruptions observed globally.
Session: Seismology's Role in Assessing Volcanic Hazard at Multiple Time Scales
Type: Oral
Date: 4/18/2023
Presentation Time: 08:15 AM (local time)
Presenting Author: John J. Lyons
Student Presenter: No
Invited Presentation:
Authors
John Lyons Presenting Author Corresponding Author jlyons@usgs.gov U.S. Geological Survey, Alaska Volcano Observatory |
Alicia Hotovec-Ellis ahotovec-ellis@usgs.gov U.S. Geological Survey, California Volcano Observatory |
Alexandra Iezzi aiezzi@usgs.gov U.S. Geological Survey, Cascades Volcano Observatory |
Matthew Haney mhaney@usgs.gov U.S. Geological Survey, Alaska Volcano Observatory |
David Fee dfee1@alaska.edu Alaska Volcano Observatory |
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Precursory Seismicity and Explosion Seismoacoustics of the Recent Phreatomagmatic Eruption of Semisopochnoi Volcano, Alaska
Category
Seismology's Role in Assessing Volcanic Hazard at Multiple Time Scales