HR: 1340h
AN: V53A-1132    [Abstracts]
TI: Seismic and Infrasound Recordings from Kilauea Volcano: Volcanic Tremor, Lava Outbreaks, and Fissure Eruptions
AU: Fee, D
EM: dfee@isla.hawaii.edu
AF: University of Hawaii, Manoa, 73-4460 Queen K Hwy, #119, Kailua Kona, HI 96740, United States
AU: Garces, M
EM: milton@isla.hawaii.edu
AF: University of Hawaii, Manoa, 73-4460 Queen K Hwy, #119, Kailua Kona, HI 96740, United States
AU: * Orr, T
EM: torr@usgs.gov
AF: U.S. Geological Survey, Hawaiian Volcano Observatory, Volcano, HI 96785, United States
AB: The continuous effusion from the Pu‘u ‘O‘o crater complex, the active vent of Kilauea Volcano, Hawaii, produced nearly continuous tremor for years. Recently this tremor was recorded by two infrasound arrays, one at 12.5 km and one at 2.5 km, as well as a broadband seismometer at the closer array. These recordings exhibit significant temporal changes. A sharp, complex spectral peak of ~0.6 Hz is present in nearly the entire dataset, and tends to bifurcate and shift frequency over time. Although the seismic wavefield at Kilauea is complex and path effects appear to play a significant role, this spectral peak is also weakly manifested in the seismic recordings. Array processing of the infrasonic data reveals an abundance of broadband signal as well. Most of the signal appears to originate from the main crater region. However, the 2.5 km array detected the presence of a skylight with growing hornitos ~400 m south of Pu‘u ‘O‘o on the active lava tube system. On June 19th, 2007, the magmatic system at Pu‘u ‘O‘o changed. An intrusion of magma reached the surface 6 km west of the crater complex. The timing and location of the lava outbreak were determined acoustically using array processing. Two distinct acoustic pulses were recorded from the correct azimuth, both exhibiting harmonics. The 7/21 fissure eruption also produced clear infrasound signals. The onset of the fissure eruption east of P‘u‘ ‘O‘o was apparent beginning around midnight on 7/21 and was focused between ~1.5-5 Hz. Although the fissure eruption continued to produce infrasound, the character of the recorded signal changes over time. A third infrasound array was placed closer to P‘u‘ ‘O‘o and the fissure to help further constrain the eruption. More detailed results on acoustic signals from the Father's Day Intrusion and Fissure eruption will be presented.
DE: 8419 Volcano monitoring (7280)
DE: 8425 Effusive volcanism
DE: 8485 Remote sensing of volcanoes
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting