Mount Ruapehu ski season visitors told to avoid 'volcanic hazard zones'

Visitors to the slopes of Mount Ruapehu are being warned to stay at least two kilometres away from the volcano's Crater Lake due to the increased risk of eruption.

Mt Ruapehu is going into ski season under Volcanic Alert Level 2, the same level applied to Whakaari/White Island when it erupted in 2019.

Department of Conservation Tongariro visitor safety ranger Theo Chapman said this had been the longest period of heightened unrest at Ruapehu in decades.

"As such, it has given us opportunity to consider scenarios we had not previously included in the reviews of our eruptive hazard management plans."

High levels of volcanic unrest will affect ski season, DOC says. Photo / Supplied

The department has issued public reminders stating, "eruptions can occur at any time without warning".

To reduce the risk of being exposed to volcanic hazards, it is telling visitors to Mt Ruapehu to minimise time in valleys and rivers that are paths for fast-moving volcanic mud flow and shorten any time spent in the 3km Summit Hazard Zone.

A 2km exclusion zone around the volcano's summit and Crater Lake will be off-limits to visitors.

GeoNet duty volcanologist Craig Miller said as of Tuesday unrest at Mt Ruapehu was moderate with temperatures at the Crater Lake sitting at 28C.

"Within the next three weeks, the most likely outcomes of the ongoing unrest are either minor eruptive activity that is confined to the lake basin or no eruption."

GeoNet has recorded "moderate" unrest at the Crater Lake but the potential for eruption remains. Photo / File

Miller said the next likely scenario was a larger eruption similar to the one which happened in September 2007.

"An eruption of this size would cause life-threatening hazards on the summit plateau and in valleys impacted by lahars."

Miller said the chances for an eruption on the level of the 1995 and 1996 events were higher than in March but remained "very unlikely" in the next three weeks.

"Such an eruption would most likely only follow a sequence of smaller eruptions."

GeoNet has set the Volcanic Alert Level to remain at Level 2 while the Aviation Colour Code remains at Yellow.

Operators of Mt Ruapehu Whakapapa, Turoa and Tukino ski fields were contacted for comment.

DOC has asked visitors to avoid the 2km Exclusion Zone at Mt Ruapehu. Image / Supplied

What to do

Before you go

• Know where the volcanic hazards zones are

• Consider whether you're comfortable with the volcanic risk associated with your trip.

In an eruption

• Move immediately away from the eruption site, staying out of valleys.

• If you're in a valley, move sideways to higher ground.

• If you see flying rocks or a steam and ash cloud coming towards you, take shelter behind a bank or ridge and cover your head with your pack.

Source: Department of Conservation