HR: 11:55h
AN: T31H-07    [PDF]
TI: Anatahan Eruption of May, 2003: Integrated Response of the MARGINS Community
AU: * Hilton, D R
EM: drhilton@ucsd.edu
AF: Geosciences Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093 United States
AU: Fischer, T P
EM: Fischer@unm.edu
AF: Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131 United States
AU: Wiens, D A
EM: doug@seismo.wustl.edu
AF: Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130 United States
AU: Camacho, J T
EM: juantcamacho@hotmail.com
AF: Emergency Management Office, Capital Hill, Saipan, 96950 United States Minor Outlying Islands
AB: Following the May 10 eruption, the MARGINS office responded by authorizing helicopter surveillance of the eruption and ship deployment to visit Anatahan. The helicopter flights allowed for (a) visual inspection of the impact of the eruption, (b) identification of the source of the eruption (east crater), (c) collection of bombs and tephra from the eruption, and (d) deployment of a seismometer. The ship visit followed, and consisted of (a) maintenance and data retrieval from a previously-deployed seismic station, (b) collection of more samples, and (c) deployment of COSPEC instrumentation (for volatile flux measurement). The eruption has therefore presented the MARGINS community with an unique opportunity to integrate geophysical, geochemical and volcanological observations of an active, SiO$_{2}$-rich volcano located on a targeted margin. This presentation will highlight on-going studies of the May event which will be presented in detail in the accompanying special session. Topics to be presented include (1) seismicity associated with the eruption, which was well monitored by a PASSCAL broadband seismograph fortuitously installed on Anatahan 4 days prior to the eruption, (2) geochemistry of the erupted products. This includes ICP analysis of the major and trace element chemistry, electron microprobe analysis on selected mineral phases, plus the isotope systematics (Sr-Nd-Pb-Hf-O-U-series) of selected samples, (3) volcanological observations on eruption initiation and evolution plus estimates of volatile flux rates within 11 days of the start of the eruption, and (4) hazard assessment of the eruption and mitigation strategies.
DE: 1010 Chemical evolution
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3640 Igneous petrology
DE: 8015 Local crustal structure
SC: Tectonophysics [T]
MN: 2003 Fall Meeting