Ruapehu Update 003

Contributed by:

Dr Graeme Wheller, a Consultant Geologist

with Volcanex International Pty Ltd

g.wheller@geol.utas.edu.au

'The Australian'  - Tuesday 26 September 1995

VOLCANO GETS UP STEAM FOR BIGGEST BLOW IN 450 YEARS

by Pattrick Smellie (New Zealand Correspondent)

The central North Island of New Zealand was on civil emergency alert last
night, waiting for what threatens to be Mt Ruapehu volcano's most
spectacular eruption in 450 years.

The mountain spewed rock, mud and ash over hundreds of square kilometres in
a string of eruptions yesterday which pushed up a steam plume as high as
10km and deposited ash on eastern coastal towns up to 140km away.

Families from an army base at Waiouru, near the base of the mountain, were
evacuated last night to allow soldiers to be ready for any emergency.

As activity intensified, volcanologists declared a stage-four alert, on a
scale of five, denoting "a large imminent eruption" and danger to human life.

"On the pattern to date, I would suggest that we are likely to see a big
eruption probably some time in the next day or so," said Dr Harry Bees, a
Department of Conservation scientist working on the mountain. "The kettle is
boiling vigorously now."

But the volcanologists who upgraded the alert and are monitoring the
mountain around the clock were more cautious. "We have no idea whether this
will last for days or weeks, or whether it will die down," said a spokesman
for the Institute of Nuclear and Geological Sciences, Mr Colin Wilson. "It
all depends how much magma (molten rock) the volcano has stored up since its
last eruption."

Eruptions so far have more than equalled Ruapehu's biggest recent eruption,
in 1945, and that eruption was its biggest for 400 years. Mudflows have
already reached as far as a railway bridge across the Tangiwai River, where
151 people died when a volcanic mudflow wiped the bridge out in one of New
Zealand's worst disasters, on Christmas Eve 1953.

At sunset last night, a typical eruption was under way, with sheets of mud
and rock leaping from the mountain's top, while huge billowing clouds formed
and spiralled upwards at great 
speed. The usually snow-covered mountain's eastern side is black with ash
falls, while a huge black streak runs down its western side where one of the
mudflows has been running.

"There were bits as big as cars going maybe 500m up in the air," said Mr
Winnie Sage, a commercial pilot who reported heavy bookings for nights to
look at the eruptions until a nofly zone was declared yesterday.

Late yesterday, population centres covering about 100,000 people in a 100km
radius around the mountain were placed on general alert and authorities in
towns closest to the mountain were still consideriner whether to declare a
state of civil emergency.

However, while roads circling the mountain were closed overnight, there has
so far been no evacuation of tourists and business owners. Police are
warning sightseers against going anywhere near the mountain.