The volcanic alert level for Ruapehu has been increased from level 1 to level 2 due to an increase in the output of volcanic gas from Mt Ruapehu's Crater Lake.
Wanganui District Council emergency manager Matthew Smith said GNS Science advised of the change yesterday.
"It is important to emphasise
that an increased level of unrest is not yet an eruption of Mt Ruapehu and does not mean an eruption will occur," he said.
"GNS will continue their monitoring of Mt Ruapehu and at the local level, Whanganui Civil Defence Emergency Management will review volcanic hazard plans while the duty officer continues to receive any updates."
Mr Smith said that in the event of a very large eruption the possible hazard for Whanganui district was volcanic ash fall, but the prevailing wind direction would take ash from Mt Ruapehu towards the East Coast. GNS duty volcanologist Geoff Kilgour said the temperature of Ruapehu's Crater Lake had been rising since mid-April and for the last couple of days had ranged between 45C and 46C.