Date: 11 May 2016
GNS Science have issued a Volcanic Alert Bulletin today and raised the Volcanic Alert Level to 2 ("moderate to heightened unrest"). The bulletin summarises recent measurements at Ruapehu and notes the data imply a higher likelihood of activity.
The Summit Hazard Zone is the area within two kilometres of the centre of Crater Lake. It encompasses all the peaks in the summit area with Te Heuheu Peak on the north end of the summit area at the edge of the zone.
Climbers and trekkers should refer to the Summit Hazard Zone map or use their map and GPS reading skills, to determine when they are approaching the zone.
"We recommend climbers, trampers and walkers do not enter the zone” says Paul Carr DOC Operations Manager for Tongariro. “Guiding companies should also heed the advice and not take people into the zone."
He said it was important to remember Ruapehu was always active and went through periods of activity, and therefore was being constantly monitored.
DOC keeps in close communications with GNS Science who continue to monitor the mountain closely. The department has also discussed the situation with Ngāti Tūwharetoa through Ngāti Hikairo ki Tongariro, Ngāti Rangi and Ngāti Uenuku, and advised Ruapehu Alpine Lifts and other local government agencies such as the New Zealand Police.
"We will update the warning when more information is available. Both the DOC and GeoNet websites will be kept updated," Paul said.
The Eruption Detection and Lahar Warning systems operated by the department are all fully operational and continue to be tested regularly says Dr Harry Keys, DOC Technical Advisor Volcanology.
No ski areas, other facilities or roads on Ruapehu or elsewhere in Tongariro National Park are affected by this warning.
"People should be aware of an increased possibility of lahars on the Round the Ruapehu Mountain Track.
"Rivers draining the Crater Lake and Summit Hazard Zone might suddenly rise so people approaching the Whangaehu, Mangaturuturu, Whakapapaiti and Whakapapanui streams in particular should be conscious of potential lahar noise from upstream, and make their way across these streams quickly," says Harry.
Mt Tongariro and the Tongariro Alpine Crossing are not affected.