Migration of mechanical perturbations estimated by seismic coda wave interferometry during the 2018 pre-eruptive period at Kīlauea volcano, Hawaii

Abstract

We use seismic ambient noise correlation and coda wave interferometry to estimate velocity variations at high temporal resolution, during the pre-eruptive period and the onset of the 2018 eruption of Kilauea volcano. A progressive velocity increase is observed from March to the end of April. It is followed by rapid decrease starting a few days before the onset of the East Rift Zone (ERZ) eruption and then by sharp velocity drop when the eruption started. The change of trend from velocity increase to decrease is progressively delayed by a few days from the summit caldera toward the ERZ. The location of the velocity perturbations shows a migration of the sources of velocity changes from the summit caldera toward the ERZ before the eruption. Using a model of pressure source, we show that the simultaneous caldera inflation and velocity increase probably result from an anisotropic distribution of fault and crack orientations. The velocity decrease could be due to damaging processes above the shallow reservoir and to plastic deformations around the caldera. We introduce a forward model of rock damage associated with the volcano-tectonic seismicity to calculate the velocity decrease. The good agreement between the calculated and the observed velocity variations shows that a large part of the velocity decrease results from damage of the medium. The delayed onsets of velocity decrease and the source migration of velocity perturbations are probably related to progressive fault openings in the Southern and Eastern parts of the caldera and to magma transfer toward the ERZ.

Migration of Mechanical Perturbations Estimated by Seismic Coda Wave Interferometry During the 2018 Pre‐Eruptive Period at Kīlauea Volcano, Hawaii

“…The continuous waveforms were processed to compute the NCFs using the code MSNoise (available via http:// www.msnoise.org). The NCFs used in this paper are available via the Zenodo archive (https://doi.org/10.5281/ zenodo.8104792) (Muzellec et al, 2023). GPS data are archived with the University NAVSTAR Consortium (UNAVCO; https://www.unavco.org) and radial tilt data are available in Johanson and Miklius (2019).…”

“…The seismic catalog used in this paper is available from the United States Geological Survey (USGS) (https://earthquake.usgs.gov/earthquakes/search/) and via the Zenodo archive (https://doi. org/10.5281/zenodo.8104792) (Muzellec et al, 2023).…”

“…GPS data are archived with the University NAVSTAR Consortium (UNAVCO; https://www.unavco.org/) and radial tilt data are available in Johanson and Miklius (2019). The GNSS data used in this paper are also available via the Zenodo archive (https://doi.org/10.5281/zenodo.8104792) (Muzellec et al., 2023). The seismic catalog used in this paper is available from the United States Geological Survey (USGS) (https://earthquake.usgs.gov/earthquakes/search/) and via the Zenodo archive (https://doi.org/10.5281/zenodo.8104792) (Muzellec et al., 2023).…”

“…GPS data are archived with the University NAVSTAR Consortium (UNAVCO; https://www.unavco.org) and radial tilt data are available in Johanson and Miklius (2019). The GNSS data used in this paper are also available via the Zenodo archive (https://doi.org/10.5281/zenodo.8104792) (Muzellec et al, 2023). The seismic catalog used in this paper is available from the United States Geological Survey (USGS) (https://earthquake.usgs.gov/earthquakes/search/) and via the Zenodo archive (https://doi.…”

“…The seismic data analyzed in this paper are available from the Incorporated Research Institutions for Seismology (IRIS) Data Management Center under network code HV (http://ds.iris.edu/mda/HV/). A code to download the seismic data is available via the Zenodo archive (https://doi.org/10.5281/zenodo.8104792) (Muzellec et al., 2023). The continuous waveforms were processed to compute the NCFs using the code MSNoise (available via http://www.msnoise.org/).…”