December 19, 2004
NZ City
The Department of Conservation says a significant lahar on Ruapehu is unlikely to happen before Christmas.
DOC scientist Harry Keys says unseasonably cold weather and a good dumping of snow is slowing the melting into the lake. But although there are seven to eight metres to go before the lake breaches the outlet, scientists are not taking any chances.
Harry Keys says Mount Ruapehu is an active volcano and that means the ongoing risk of lahars, so DOC and the government have made plans to keep people out of harm's way. If warm weather does arrive this summer, DOC warns there could be a major lahar in the next couple of months.
http://home.nzcity.co.nz/news/default.asp?id=45996&c=w
Crater Lake Creeps Higher
December 29, 2004
By MIKE WATSON
Dominion Post
Photo: SPILLING OVER: DOC predicts a lahar from Mt Ruapehu's crater lake could be less than 18 months away. (ROSS GIBLIN/Dominion Post)
Mt Ruapehu's crater lake is at its highest level since the 1995 eruptions having risen 53 centimetres since its last recording three weeks ago.
And the Conservation Department predicts a lahar could happen within 18 months, with the lake level now at 87cm below the crater rim and 9m below the tephra dam the layer of ash, scoria and rocks on top. The dam, which was formed by debris from the 1995-96 eruptions, blocks a channel that once let water flow from the lake.
The lake contains almost nine million cubic metres of liquid. When full, the crater would hold 10.5 million cubic metres, equal to three Westpac Stadiums or 50,000 Olympic-size swimming pools.
Recent rain and mild weather had caused snow melt, which raised the crater lake's level.
Earth scientist Harry Keys said the new level was the highest recorded reading but the lake was not about to burst through its crater outlet.
Specialists believe the tephra dam will not become unstable till the lake level rises another five metres. It has an early warning system which is regularly checked.
Mt Ruapehu eruptions have caused 15 lahars since 1953, when a big lahar wiped out the Tangiwai rail bridge and killed 151 people. The department will monitor the lake now.
http://www.stuff.co.nz/stuff/0,2106,3141752a7693,00.html
Ruapehu Crater Lake Level 'Low to Normal'
January 1, 2005
Dominion Post
The Mt Ruapehu crater lake warning level is at "low to normal", with no increased chance of a lahar happening, the Conservation Department says.
Department scientist Harry Keys said the crater lake was filling at 3900 cubic metres a day (about enough to fill 1-1/2 Olympic swimming pools), which is less than normal for this time of year.
Recent cold conditions have resulted in little snow melt.
At the current rate of filling, the lake will not reach the crater rim tilltill later this month or early February.
Dr Keys said it looked unlikely that the lake would reach an unstable level within five metres of the tephra dam this summer or autumn.
http://www.stuff.co.nz/stuff/0,2106,3144627a7693,00.html
Intervene Over Ruapehu Lake - NZ First
Wednesday, 22 December 2004, 4:39 pm
Press Release: New Zealand First Party
Intervene Over Ruapehu Lake
December 22, 2004
Press Release: New Zealand First Party
NZ First
New Zealand First has asked the Ministers of Internal Affairs and Conservation to urgently consider adopting interventionist strategies on the Ruapehu crater lake to minimise the risk to surrounding areas.
“I am aware that the Ruapehu District Council has a major emergency management plan, that appropriate warning devices are in place, and that Government funding and advice has been available,” said Local Government and Environment spokesperson Jim Peters.
“Notwithstanding the plan, nothing is in place which would really alleviate the dramatic impact should the lake break through its highest bunding level.
“The Government needs to urgently rethink its historical unwillingness to face up to the impact of a potential disaster, and the likely consequences on the downstream and down-country communities,” said Mr Peters.
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