Seismic characterization of explosive and collapse events at the Kilauea summit during the 2018 eruption
Abstract
Characterizing the large seismic events associated with the eruptions and caldera collapses is important to understanding the mechanism behind the caldera collapse and monitor the overall evolution of the caldera-rift zone system. During the 2018 Kilauea eruption, a total of 62 significant Mw 4.7 to 5.4 seismic events occurred at the summit between May 17 and August 2. Several approaches including moment tensor inversion, particle motion analysis and infrasound simulation are used to constrain the source mechanism, location and depth of these events. Resolving the non double-couple components for shallow volcanic sources using long period seismic waves at teleseismic distances is challenging because there is a trade-off between the vertical compensated-linear-vector-dipole (vertical CLVD) and isotropic components as traction goes to zero at free surface (Kawakatsu 1996). We show that the availability of near-field stations at the summit allow us to resolve the strong isotropic component for the first 12 large events (May 17 to 26). However, for the later events (May 29 to Aug 2), the isotropic components are not well resolved from moment tensor inversion due to signal-clipping at near-field seismic stations. With isotropic constraints from geodetic modeling results, we are able to use long period seismic waves recorded at teleseismic distances to determine the ring-fault geometry, and therefore better understand the role of these large seismic events in modulating the overall eruption sequence.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMV002.0012L
- Keywords:
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- 7280 Volcano seismology;
- SEISMOLOGY;
- 8414 Eruption mechanisms and flow emplacement;
- VOLCANOLOGY;
- 8419 Volcano monitoring;
- VOLCANOLOGY;
- 8488 Volcanic hazards and risks;
- VOLCANOLOGY