TY - JOUR
T1 - Modulation of seismic activity in Kīlauea's upper East Rift Zone (Hawai'i) by summit pressurization
AU - Wauthier, Christelle
AU - Roman, Diana C.
AU - Poland, Michael P.
N1 - Funding Information:
We thank the staff of the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) for providing data and feedback for this work, in particular Asta Miklius for GPS processing, Wes Thelen for raw seismic waveform data, and Matt Patrick for suggestions and background information regarding the correlation between the summit lava lake level and Kilauea's upper East Rift Zone seismicity rates. The HVO GPS network is operated in collaboration by the USGS, Stanford University (Stanford, California, USA), and Pacific GPS Facility at the University of Hawai'I (Honolulu). We are grateful to Emily Montgomery-Brown, Cindy Ebinger, and two anonymous reviewers for their comments, which substantially improved the manuscript.
Publisher Copyright:
© 2019 Geological Society of America.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019
Y1 - 2019
N2 - Kīlauea Volcano (Hawai'i, USA) is underlain by a complex, laterally extensive magmatic plumbing system. Although in recent decades it has mainly erupted through vents along the middle East Rift Zone and summit caldera, eruptions can occur anywhere along its laterally extensive rift zones, as demonstrated by the dramatic eruptive activity of 2018. Forecasting eruptive activity requires an understanding of whether an episode of volcano-seismic unrest at Kīlauea and similar volcanoes is caused directly at the edges of an active intrusion or reservoir, or in a volume of wall rock at a distance from the intrusion. Seismic unrest in Kīlauea's upper East Rift Zone (UERZ) has to date been interpreted as the result either of magma intrusion in this region of the volcano or of stresses due to seaward flank migration. However, recent observations suggest that UERZ seismicity may result from variable pressurization of Kīlauea's summit magma system. We analyze seismic and deformation (multi-temporal interferometric synthetic aperture radar [InSAR] and GPS) data during a period of variable summit deformation and UERZ seismicity in mid- to late 2007 and calculate Coulomb stress changes on UERZ faults due to modeled summit inflation or deflation. UERZ seismicity during our study period can be explained entirely by stresses arising from pressure changes within Kīlauea's summit reservoirs. Furthermore, a comparison of UERZ fault plane solutions (FPSs) calculated for this study to published UERZ FPSs for previous periods suggests that the UERZ has undergone a transition from a mechanically strong, discontinuous, and immature magma transport system to a mature, mechanically weak, and fully connected transport system over the course of the 1983-2018 eruption.
AB - Kīlauea Volcano (Hawai'i, USA) is underlain by a complex, laterally extensive magmatic plumbing system. Although in recent decades it has mainly erupted through vents along the middle East Rift Zone and summit caldera, eruptions can occur anywhere along its laterally extensive rift zones, as demonstrated by the dramatic eruptive activity of 2018. Forecasting eruptive activity requires an understanding of whether an episode of volcano-seismic unrest at Kīlauea and similar volcanoes is caused directly at the edges of an active intrusion or reservoir, or in a volume of wall rock at a distance from the intrusion. Seismic unrest in Kīlauea's upper East Rift Zone (UERZ) has to date been interpreted as the result either of magma intrusion in this region of the volcano or of stresses due to seaward flank migration. However, recent observations suggest that UERZ seismicity may result from variable pressurization of Kīlauea's summit magma system. We analyze seismic and deformation (multi-temporal interferometric synthetic aperture radar [InSAR] and GPS) data during a period of variable summit deformation and UERZ seismicity in mid- to late 2007 and calculate Coulomb stress changes on UERZ faults due to modeled summit inflation or deflation. UERZ seismicity during our study period can be explained entirely by stresses arising from pressure changes within Kīlauea's summit reservoirs. Furthermore, a comparison of UERZ fault plane solutions (FPSs) calculated for this study to published UERZ FPSs for previous periods suggests that the UERZ has undergone a transition from a mechanically strong, discontinuous, and immature magma transport system to a mature, mechanically weak, and fully connected transport system over the course of the 1983-2018 eruption.
UR - http://www.scopus.com/inward/record.url?scp=85072025759&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072025759&partnerID=8YFLogxK
U2 - 10.1130/G46000.1
DO - 10.1130/G46000.1
M3 - Article
AN - SCOPUS:85072025759
VL - 47
SP - 820
EP - 824
JO - Geology
JF - Geology
SN - 0091-7613
IS - 9
ER -