HR: 1340h
AN: V53A-1139 [Abstracts]
TI: Source Models of the June 17th, 2007 Kilauea Intrusion: Monte Carlo Optimization
AU: * Sinnett, D K
EM: dsinnett@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305,
United States
AU: Montgomery-Brown, E D
EM: emilyd@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305,
United States
AU: Segall, P
EM: segall@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305,
United States
AU: Miklius, A
EM: asta@usgs.gov
AF: USGS Hawaiian Volcano Observatory, PO Box 51, Hawaii National Park, HI 96718, United
States
AU: Poland, M
EM: mpoland@usgs.gov
AF: USGS Hawaiian Volcano Observatory, PO Box 51, Hawaii National Park, HI 96718, United
States
AU: Yun, S
EM: sangho.yun@gmail.com
AF: U.S. Geological Survey, 345 Middlefield Road MS 977, Menlo Park, CA 94025, United
States
AU: Zebker, H
EM: zebker@pangea.stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305,
United States
AB:
Father's Day, 17 June 2007, marked the beginning of the 56th episode of the ongoing eruption of Kilauea volcano,
Hawaii. The episode culminated in a short-lived eruption approximately 6 km west of Pu\`{}u \`{}O\`{}o and 13 km
southeast of Kilauea summit. The interruption of magma supply to, and withdrawal from, the reservoir beneath
Pu\`{}u \`{}O\`{}o caused cessation of activity and ~100 m of crater floor subsidence there. The continuous and
campaign GPS, electronic tiltmeter, and seismic networks, as well as InSAR captured the episode in fine detail.
Visual inspection of the data show subsidence at Kilauea summit and Pu\`{}u \`{}O\`{}o, which fed the inflating
dike. We began by modeling the intrusion with a Mogi source beneath Kilauea summit and a dislocation with
uniform opening beneath the east rift zone embedded in an isotropic, homogenous, elastic, half space. We invert
for the 12 source parameters (length, width, depth, dip, strike, horizontal position, and opening of the dike, and
position, depth, and volume change of the Mogi source) using Monte Carlo optimization. The inversion used
three component displacement data from 23 continuous and campaign GPS stations, diurnally and tidally filtered
tilt from 6 stations, and an ENVISAT InSAR interferogram spanning 04/12/07 to 06/21/07 decimated using a
quadtree algorithm. The optimum model included ~-4.1 * 106 m3 of volume loss from a reservoir 3
km beneath the summit, and a total dike volume of ~19*106 m3 (~4.84 km length x 2.45 km
width x 1.6 m opening at 2.4 km depth). The discrepancy between summit volume loss and total dike volume
suggests that other sources must have fed the dike. A crude estimate of volume loss from Pu\`{}u \`{}O\`{}o is
8.5*106 m3 accounting for ~ 66% of the volume of the dike. The eruption site lies inside the
eastern edge of the model, and ~0.5 km to the south of the best fit dike top. The best fit dike top parallels
the northern margin of an area of ground cracking near Makaopuhui and terminates at its western margin near
Mauna Ulu. The western termination is ~2.5 km east of the westernmost observed ground cracks. Within
95% bounds the dike top may intersect the eruption area and extend to all regions of ground cracking. It is also
interesting to note that this dike is located in an area between the 1997 and 1999 intrusions. The best fit single
dislocation model explains only 35% of the variance in the data. This is in part due to the inadequacies of a
single planar dike with uniform opening to explain surface deformation and perhaps to inelastic deformation
associated with ground cracking near the western edge of the dike. Models with distributed opening, in which the
dike plane honors the optimization results as well as the region of decorrelation in the ENVISAT interferogram,
explain 69% of the data (Montgomery-Brown et al., this session).
DE: 8400 VOLCANOLOGY
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting