HR: 1340h
AN: OS23B-1315    [Abstracts]
TI: Pyroclastic Flow Generated Tsunami Waves Detected by CALIPSO Borehole Strainmeters at Soufriere Hills, Montserrat During Massive Dome Collapse: Numerical Simulations and Observations
AU: * Van Boskirk, E J
EM: evanbos@uark.edu
AF: University of Arkansas, Department of Geosciences Ozark Hall Rm #113, Fayetteville, AR 72701 United States
AU: Voight, B
EM: voight@ems.psu.edu
AF: Pennsylvania State University, College of Earth and Mineral Sciences, University Park, PA 16802 United States
AU: Watts, P
EM: phil.watts@appliedfluids.com
AF: Applied Fluids Engineering, Inc, Private Mail Box #237 5710 E. 7th Street, Long Beach, CA 90803 United States
AU: Widiwijayanti, C
EM: cwidiwiji@geosc.psu.edu
AF: Pennsylvania State University, College of Earth and Mineral Sciences, University Park, PA 16802 United States
AU: Mattioli, G S
EM: mattioli@uark.edu
AF: University of Arkansas, Department of Geosciences Ozark Hall Rm #113, Fayetteville, AR 72701 United States
AU: Elsworth, D
EM: elsworth@psu.edu
AF: Pennsylvania State University, College of Earth and Mineral Sciences, University Park, PA 16802 United States
AU: Hidayat, D
EM: hidayat@geosc.psu.edu
AF: Pennsylvania State University, College of Earth and Mineral Sciences, University Park, PA 16802 United States
AU: Linde, A
EM: linde@dtm.ciw.edu
AF: Carnegia Institution Washington, Department of Terrestrial Magnetism 5241 Broad Branch Road, NW, Washington, DC 20015 United States
AU: Malin, P
EM: malin@duke.edu
AF: Duke University, Division of Earth and Ocean Sciences 109 Old Chemistry, Durham, NC 27708 United States
AU: Neuberg, J
EM: J.Neuberg@earth.leeds.ac.uk
AF: Leeds University, School of Earth & Environment Earth Sciences Rm 8/15i, Leeds, LS2 9JT United Kingdom
AU: Sacks, S
EM: sacks@dtm.ciw.edu
AF: Carnegia Institution Washington, Department of Terrestrial Magnetism 5241 Broad Branch Road, NW, Washington, DC 20015 United States
AU: Shalev, E
EM: shalev@duke.edu
AF: Duke University, Division of Earth and Ocean Sciences 109 Old Chemistry, Durham, NC 27708 United States
AU: Sparks, R J
EM: Steve.Sparks@bristol.ac.uk
AF: University of Bristol, Department of Earth Sciences Wills Memorial Building Queen's Road, Bristol, BS8 1RJ United Kingdom
AU: Young, S R
EM: sy@caribsurf.com
AF: Pennsylvania State University, College of Earth and Mineral Sciences, University Park, PA 16802 United States
AB: The July 12-13, 2003 eruption (dome collapse plus explosions) of Soufriere Hills Volcano in Montserrat, WI, is the largest historical lava dome collapse with $\sim$120 million cubic meters of the dome lost. Pyroclastic flows entered the sea at 18:00 AST 12 July at the Tar River Valley (TRV) and continued until the early hours of 13 July. Low-amplitude tsunamis were reported at Antigua and Guadaloupe soon after the dome collapse. At the time of eruption, four CALIPSO borehole-monitoring stations were in the process of being installed, and three very-broad-band Sacks-Evertson dilatometers were operational and recorded the event at 50 sps. The strongest strain signals were recorded at the Trants site, 5 km north of the TRV entry zone, suggesting tsunami waves $>$1 m high. Debris strandlines closer to TRV recorded runup heights as much as 8 m. We test the hypothesis that the strain signal is related to tsunami waves generated by successive pyroclastic flows induced during the dome collapse. Tsunami simulation models have been generated using GEOWAVE, which uses simple physics to recreate waves generated by idealized pyroclastic flows entering the sea at TRV. Each simulation run contains surface wave amplitude gauges located in key positions to the three borehole sites. These simulated wave amplitudes and periods are compared quantitatively with the data recorded by the dilatometers and with field observations of wave runup, to elucidate the dynamics of pyroclastic flow tsunami genesis and its propagation in shallow ocean water.
DE: 8419 Eruption monitoring (7280)
DE: 8494 Instruments and techniques
DE: 4255 Numerical modeling
DE: 4564 Tsunamis and storm surges
DE: 0370 Volcanic effects (8409)
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting