Tonnes of pumice wash ashore in Lake Taupō

Twins Finn and Otis (left) and Oisin play in the huge raft of pumice at Waitetoko Beach, Tauranga Taupo Bay, Lake Taupō. Photo / Dan Hutchinson

A huge raft of pumice has gathered in a Lake Taupō bay, possibly as a result of debris generated by recent earthquake activity which has then been washed down rivers on the eastern side of the lake.

The strange phenomenon can be found at Waitetoko Beach in Tauranga Taupō Bay and stretches for about 1km along the shoreline and is about 20 metres wide.

GNS Science geologist Dr Michael Rosenberg said there has not been any eruption activity to cause the pumice raft.

A huge pumice raft gathers in Waitetoko Beach, Tauranga Taupo Bay, Lake Taupō. Photo / Dan Hutchinson

“If the pumice pieces are rounded, like most typical beach/river-washed pumice are, it is most likely they were washed down the nearby river and could be a result of earth movement.

“We know that some of the land around the Taupō area is already unstable due to extended periods of rain, and some areas were also affected by the 30th November earthquake.

“We are seeing areas of erosion, and weak areas that are vulnerable. It’s possible a new slip has occurred, or that an existing one has moved further and slumped into the river catchment, and that has generated the pumice raft.”