DESTRUCTIVE LAHARS DON'T FOLLOW HAZARD MODELS.

The article presents a field study conducted on the lahar surging down the Whangaehu River channel from Mount Ruapehu which found lahars to become more destructive as they travel along river channels. Theoretical models are cited to suggest lahars to dissipate in energy as it flows downslope. The observed lahar is described to have behaved like an open system, and incorporated brine-free river water and sediment to gain energy for long-distance travel.