Ruapehu's crater viewpoints now accessible

Ruapehu Bulletin, Volume 13, Issue 615, 5 December 1995, Page 3

Ruapehu's crater viewpoints now accessible

Eruption Alert lowered to Level Two

Experienced climbers and guided parties are now able to view Mt Ruapehu's active crater from two peaks overlooking it. T ahurangi and Paretetaitonga peaks can be ascended by properly equipped people able to make their own judgements about alpine and volcanic hazards, stated Department of Conservation officials last week. Following examination of volcano surveillance data the Institute of Geological and Nuclear Sciences have lowered the alert status for the volcano to Level Two. They warn that close to the active vents there still remains a high risk from sudden eruptions and significant hazards from toxic volcanic gas and that the eruption is not yet over. "Due to volcanic hazards no-one should go within 800 metres of the centre of the present active crater system", said Paul Green, regional conservator of the Tongariro/Taupo Conservancy of the Department of Conservation. "That encompasses all areas inside the crater basin which are within 500 metres of the shore of the former Crater Lake. This means that it is not safe to use the last parts of traditional routes onto the Dome, the Col or Mangaturuturu Saddle. We ad-

vise people to go no closer than Tahurangi or Paretetaitonga peaks". Mr Green emphasised that in certain wind conditions the presence of volcanic gas will make even these peaks dangerous to approach. "But when clear both the two peaks enable excellent views down into the 1 20- 1 50 metre deep crater system," he said. Conservation staff were working on the mountain on Wednesday, fully equipped with alpine gear and gas masks. 'The crater is composed of two main sub-craters both of which are now joined and partly flooded by a steaming lake," said Harry Keys, advisory scientist from the Department of Conservation. "Small boil-ing-like eruptions are occurring periodically in this lake. Smaller craters and vents discharging gas and steam surround the lake and several are encrusted with bright yellow sulphur deposits. At least one vent is npisily discharging gas at high pressure". People climbing on Ruapehu should exercise caution and judgement in addition to precautions normally required above the snowline. They need to be adequately experienced and equipped. Sudden explosive eruptions large enough to threaten people Turn to Page 5

Crater access

FROMPAGE3 up to two kilometres from the crater are still possible although the danger to individuals is now relatively low. Toxic gas is being emitted in sufficient quantities to affect people around and downwind of the crater. There are also significant potential hazards from erupted lahars (mudflows) and secondary debris flows on the Whangaehu Glacier and valley within 2.5 kilometres from the crater which includes the slopes around Whangaehu Hut. "Climbers should have regard to wind direction, gas drift, forecasted weather and the possibility of ash deposits anywhere on the mountain being de-estabilised by rain or snow-melt", advised Mr Keys. "They can then make their decisions on safe routes and distances accordingly". Travel on the Round-the-Mountain track is safe as long as people recognise that there is a potential for secondary hazards, especially during and after periods of rain or melting. Trampers should not dwell in the floors of the valleys. The destruction of the bridges over the Whangaehu and Mangatoetoenui rivers may make it difficult to cross these rivers at times. A water supply has been restored at Rangipo Hut in recognition that it is now safe for people to travel between the T ukino Mountain Road and Mangaehuehu Hut as long as they are careful in the valley floors. Other huts still have their hut water supplies disconnected. However, they all have streams nearby which are safe to drink from unless there is further contamination.