Mount Maunganui is a rhyolite dome that stands 232 metres above sea level at the entrance of the Tauranga Harbour.
In January 2011, Cyclone Wilma triggered several tens of landslides at this site. This study reviews the spatial
distribution of the mass movement associated with the 2011 rainfall event and compares it to the landslide distribution
since 1943. The limit equilibrium method was use to assess the slope stability conditions of a 2011 debris avalanche.
The results demonstrate that slopes at Mount Maunganui are stable but that elevated pore pressure can lead to
landsliding. The rock fall shadow angle of the furthest observed boulder was found to be 30-31° to the top of the
initiation zone and 27-28° to the top of the talus. Using default restitution coefficients for “clean hard bedrock” and “soil
with vegetation cover” materials, the software RocFall was able to capture the extent of the observed boulder field.
