Volcanic Crater Lake Primed To Spill (NZ)

New Scientist ^ | 1-11-2007 | Emma Young

[blam]

Volcanic crater lake primed to spill

12:41 11 January 2007
NewScientist.com news service
Emma Young

Ruapehu is one of the world's most active volcanoes. The deep crater lies between its peaks and fills with a lake between big eruptions

The crater lake of New Zealand’s Mount Ruapehu is brimming and could burst at any time, releasing at least one million cubic metres of water and sending a mudflow – or lahar – gushing down the volcano.

The last Mt Ruapehu lahar, in 1953, was on a similar scale. It swept away a railway bridge, killing 151 people travelling across it. Some local newspapers are raising the prospect of another potential disaster – but scientists say they are scare-mongering.

A new automatic monitoring and alarm system, in combination with alterations to bridges and roads, and detailed predictions of the track of a lahar, mean the public should not be at risk, says Harry Keys, a geologist with the New Zealand Department of Conservation (DoC) in Tongariro/Taupo, the area that encompasses Mt Ruapehu.

Local claims that a simple engineering fix was rejected because of protests from Maori, who consider the mountain sacred, are also wrong, Keys says. Bulldozing a trench through the dam to let water escape slowly would have been a short-term solution to only this lahar threat. “What we have in place now is the best solution for managing lahars in the long term,” he says.

Alpine sports Mt Ruapehu, which is 2797 metres high, is in the North Island, about 40 km southwest of Lake Taupo, and is hugely popular for skiing, kayaking and hiking.

Its crater lake has been filling up since spectacular volcanic explosions in 1995 and 1996, which deposited ash and rocks around the crater. The lake’s level jumped...

[XEHRpa]

The cracks of Mt. Doom??

[SamAdams76]

It’s a stone groove.