HR: 1340h
AN: V43B-1428    [Abstracts]
TI: Validation of TITAN2D flow model code for pyroclastic flows and debris avalanches at Soufri\`{e}re Hills Volcano, Montserrat, BWI
AU: * Widiwijayanti, C
EM: cwidiwij@geosc.psu.edu
AF: Dept. Geosciences, Penn State University, University Park, PA 16802 United States
AU: Voight, B
AF: Dept. Geosciences, Penn State University, University Park, PA 16802 United States
AU: Hidayat, D
AF: Dept. Geosciences, Penn State University, University Park, PA 16802 United States
AU: Patra, A
AF: Dept. Mechanical and Aerospace Eng., University at Buffalo, Buffalo, NY 14260 United States
AU: Pitman, E
AF: Dept. Mathematics, University at Buffalo, Buffalo, NY 14260 United States
AB: Soufri\`{e}re Hills Volcano (SHV), Montserrat, has experienced numerous episodes of dome collapses since 1996. They range from relatively small rockfalls to major dome collapses, several $>$10x10$^{6}$ m$^{3}$, and one $>$100x10$^{6}$ m$^{3}$ (Calder, Luckett, Sparks and Voight 2002; Voight et al. 2002). The hazard implications for such events are significant at both local and regional scales, and include pyroclastic surges, explosions, and tsunami. Problems arise in forecasting and hazards mitigation, particularly in zoning for populated areas. Determining the likely extent of flow deposits is important for hazard zonation. For this, detailed mapping (topography of source areas and paths, material properties, structure, track roughness and erosion) has an important role, giving clues on locations of future collapse and runout paths. Here we present an application of a numerical computation model of geophysical mass flow using the TITAN2D code (Patra et al. 2004; Pitman et al. 2004), to simulate dome collapses at SHV. The majority of collapse-type pyroclastic flows at SHV are consistent with an initiation by gravitational collapse of oversteepened flanks of the dome. If the gravity controls the energy for such processes, then the flow tracks can be predicted on the basis of topography, and friction influences runout. TITAN2D is written to simulate this type of volcanic flow, and the SHV database is used to validate the code and provide calibrated data on friction properties. The topographic DEM was successively updated by adding flow deposit thicknesses for previous collapses. Simulation results were compared to observed flow parameters, including flow path, deposit volume, duration, velocity, and runout distance of individual flows, providing calibration data on internal and bed friction, and demonstrating the validity and limitations of such modeling for practical volcanic hazard assessment.
DE: 8400 VOLCANOLOGY
DE: 8419 Eruption monitoring (7280)
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting