Geometric
Mobility
parameter
•Surges and column collapse flows are systematically more mobile (they spread further for a given volume) than dome collapse flows and avalanches.
•
•Order of magnitude difference in their mobility ratios
•
•These are expanded currents where fluidization and/or turbulence play dominant role in particle support mechanism.
Also look at Mobility as defined by A (area inundated) - how far it is able to spread.

1. Dome collapse pfs consistent with debris avalanches
2. Pumice flows - spread thinner than Dome collapse flows and cold debris avalanches
3. AV2/3 = geometric mobility parameter suggested by this analyses where resisting shear stress is assumed as ~ constant.
4. This is independent of volume, large scatter.
5. Pumice flows are almost are an order of magnitude more mobile than dome collapse flows of a
 similar volume