HR: 11:50h
AN: T12C-07    [Abstracts]
TI: Quasi-Periodic Slow Earthquakes and Their Association With Magmatic Activity at Kilauea Volcano, Hawai`i
AU: * Brooks, B A
EM: bbrooks@soest.hawaii.edu
AF: School of Ocean and Earth Science and Technology, University of Hawaii, 1680 East-West Rd., Honolulu, HI 96822, United States
AU: Foster, J H
EM: jfoster@soest.hawaii.edu
AF: School of Ocean and Earth Science and Technology, University of Hawaii, 1680 East-West Rd., Honolulu, HI 96822, United States
AU: Sandwell, D
EM: dsandwell@ucsd.edu
AF: Scripps Institution of Oceanography, 8602 La Jolla Shores Drive, La Jolla, CA 92093, United States
AU: Poland, M
EM: mpoland@usgs.gov
AF: USGS Hawaii Volcano Observatory, PO Box 51, Hawaii National Park, HI 96718, United States
AU: Myer, D
EM: dmyer@ucsd.edu
AF: Scripps Institution of Oceanography, 8602 La Jolla Shores Drive, La Jolla, CA 92093, United States
AU: Wolfe, C
EM: cecily@soest.hawaii.edu
AF: School of Ocean and Earth Science and Technology, University of Hawaii, 1680 East-West Rd., Honolulu, HI 96822, United States
AU: Patrick, M
EM: mpatrick@mtu.edu
AF: Department of Geological/Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, United States
AB: Since 1998 the mobile south flank of Kilauea volcano, Hawai`i, has been the site of multiple slow earthquake (SE) events recorded principally with continuous GPS. One spatially coincident family of these SEs exhibited a high degree of periodicity (774 +/- 7 days) from 1998 to 2005 suggesting the next SE would be in mid-March, 2007. In fact, no anomalous deformation occurred there until the June 17 Father's day dike intrusion that caused up to 1m of opening along Kilauea's east rift zone. We analyzed deformation related to the Father's day event using GPS, tilt, ALOS and Envisat interferometry, microseismicity, and elastic dislocation modeling. Our analysis reveals significant motions of far-field sites that cannot be explained by dike-related deformation and that are very similar to previous SE displacements of the same sites, strongly suggesting that a SE occurred. Inclusion of this event in the overall time series yields SE repeat times of 798 +/- 50 days, apparently maintaining the quasi- periodicity of the Kilauea events. Furthermore, the timing of dike- and SE-related deformation and stress modeling suggest the Father's day dike triggered the slow earthquake. We explore the connection between magmatism and SEs at Kilauea and find a potential correlation between SE-timing and eruptive activity since 2000. This suggests the possibility that a mechanistic understanding of Kilauea SEs may require consideration of magmatic processes in addition to fault zone processes.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1209 Tectonic deformation (6924)
DE: 8123 Dynamics: seismotectonics
SC: Tectonophysics [T]
MN: 2007 Fall Meeting