Lahar

Lahar are a mass of flowing volcanic debris and water with a consistency similar to wet concrete. ³⁸²⁴  In its most extreme form this volcanic slurry may move at speed, covering large distances and be tens of meters high burying everything in its path. People caught in the path of a lahar have a high risk of death from severe crush injuries, drowning or asphyxiation. ⁴⁷¹⁶ Lahars often flow along river valleys previously carved by water. They are usually triggered by eruptions and may involve a combination of explosive hot debris and melting snow and ice but may also be caused by heavy rain and snow melt bursting a volcano’s crater rim. Lahars are a well documented hazard on Mount Ruapehu ³⁸²⁵  with 13 recorded since 1945. The Department of Conservation has established an early warning system ³⁸²⁶  for Mount Ruapehu, which has successfully warned of several lahars.

Last updated at 10:50AM on February 8, 2018