HR: 0800h
AN: V21A-0392    [Abstracts]
TI: Forecasting Lava Flow Hazards by Using a Combined Stochastic/Thermo-Rheological Approach
AU: * Wright, R
EM: wright@higp.hawaii.edu
AF: Hawaii Institute of Geophysics and Planetology, 1680 East-West Road, Honolulu, HI 96822, United States
AU: Harris, A J
EM: harris@higp.hawaii.edu
AF: Hawaii Institute of Geophysics and Planetology, 1680 East-West Road, Honolulu, HI 96822, United States
AU: Garbeil, H
EM: harold@higp.hawaii.edu
AF: Hawaii Institute of Geophysics and Planetology, 1680 East-West Road, Honolulu, HI 96822, United States
AB: There are many methods for predicting the area most likely to be inundated with lava during a volcanic eruption. At its simplest, such forecasting may involve the application of volcano-specific empirical length/effusion rate relationships to estimate flow length. At their most complex, such predictions may involve iteratively solving a system of equations that characterize the effects that cooling-induced changes in rheology have on the ability of lava to flow downhill, given spatial variations in slope determined from a digital elevation model. Here we describe results obtained by combining two recently published flow simulation models that provide an efficient means to predict the final dimensions (i.e. potential lengths and widths) of a lava flow. The model of Favalli et al., (2005) uses a stochastic approach to predict possible flow paths by calculating drainage paths using a vent location and a DEM. A family of possible flow paths is produced by iteratively adding random noise to the DEM and, at each step, re-running the drainage model. For large numbers of iterations the resulting family of paths results in impressive simulation of likely flow widths as a function of distance from the vent, but does not constrain flow length. The FLOWGO model presented by Harris and Rowland (2001) predicts the maximum potential length of a cooling-limited flow by estimating the effect that cooling-induced changes in rheology have on flow velocity. While FLOWGO allows for prediction of flow length, it provides no information regarding the potential area over which the lava may expand. Both models are computationally simple. Here, we present results obtained by combining these two approaches. By using the stochastic approach to predict all the areas that a lava flow could possibly invade (in effect forecasting the maximum potential flow width at all distances from the vent) and the thermo-rheological model to terminate these paths once the predicted cooling-limited length for the flow has been attained, this hybrid approach allows for computationally efficient simulations of lava flow hazards. A variety of case studies pertaining to Mount Etna will be used to demonstrate the potential of this approach. We also show how this model can be driven by satellite-derived lava effusion rates. As these data can be obtained in near-real-time, such an approach will allow flow simulations to be updated in response to changing eruption conditions.
DE: 8425 Effusive volcanism
DE: 8488 Volcanic hazards and risks
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting