Tongariro eruption spews ash, damages hut
MIKE WATSON AND TIM DONOGHUE
The Tongariro eruption has caused significant damage to a nearby tramping hut.
Mt Tongariro erupted for the first time in more than 100 years at 11.50pm on Monday, throwing rocks and spewing ash from the Te Mari craters.
The eruption lasted about two minutes and there were no lahars or lava flows. It was followed by a series of small earthquakes.
No one was found injured or dead during a police search of all huts and tracks around Mt Tongariro, Conservation Department Ruapehu-Whanganui area manager Nic Peet.
However, the Ketetahi hut - within 1.5 kilometres of the crater - was significantly damaged by falling debris.
"The track into the hut has got boulders of up to a metre in cross section that have landed on the track and caused impact craters and the hut itself has holes through the roof, the floor and the bunks inside it."
People could have been injured or killed had they been inside it, Mr Peet said.
Three men who were at the Mangatepopo hut, which was not in the volcanoes firing line, walked out safely this morning.
The Tongariro Alpine Crossing, the Tongariro Northern Circuit and the four huts on the mountain were now closed for public safety reasons, Mr Peet said.
The rest of the national park remains open, including the Whakapapa and Turoa skfields on Mt Ruapehu.
In the next 24 to 72 hours the department will be working with GNS on a risk assessment of the Tongariro National Park facilities and access to tracks.
Inspector Brett Crowe of Taupo police said it will work closely with the experts to determine what assistance they can provide.
The eruption generated an ash plume and ash fall, which blanketed nearby properties with about five to 15 millimetres of ash.
The latest advisory from GNS Science says eruption activity has subsided and while steam clouds are being observed at the historically active Te Maari craters, there is now no ash being produced from the volcano, and there have been no lahars or lava flows.
GNS scientists have revised their alert code down from red (eruption is forecast to be imminent) to orange (volcano is exhibiting heightened unrest with increased likelihood of eruption).
Civil Defence has cancelled its "Volcanic Activity Potential Threat to New Zealand" alert.
GNS scientist Brad Scott said there was strong seismic activity for about 15 to 20 minutes after the eruption, however in the 24 hours prior and hours since, there had not been any significant activity.
The eruption was driven by the hydrothermal system, generating steam rather than molten lava.
GNS was monitoring the activity on the mountain. It had also collected ash samples for assessment.
There were five reported eruptions from the Te Mari craters between 1855 and 1897 but they had been dormant until now, the GeoNet website said.
FURTHER TROUBLE POSSIBLE IF MAGMA BEHIND ERUPTION
Though there had been no escalation in background seismicity today, the mountain could blow its top again depending on what is causing the unrest, GNS scientist Brad Scott said at a press conference in Taupo this afternoon.
‘‘If it is steam driven ... it’s unlikely to do much more because once the initial pressure drops occurred you’ll just get smaller activity.
‘‘If it is being driven by a longer term magmatic process with molten material being intruded into the volcano it may take days to weeks before that sort of shows itself.’’
Ash samples will determine what is driving the activity, he said. ‘‘It’s really just a watch this space scenario.’’
There was some seismicity detected at 10.30am, which ‘‘may have been some further small scale eruptions or activity, Mr Scott said.
However, there were no visual observations to confirm or deny whether anything happened
"The only thing that’s really come to light that’s a little bit exciting is a photograph on a Facebook page taken by some alpine guides on the Tongariro Crossing this morning just on dawn and that shows three vents active in the Te Mari crater area.
"They all appear at this time ... to be new vents. So we’re not dealing with a single vent that’s been in eruption."
ERUPTION 'LIKE THUNDER AND LIGHTNING'
A man who lives 6km from Mt Tongariro said the eruption was "like thunder and lightning and fireworks".
David Bennett, who lives on the southern shores of Lake Rotoaira, said he and other locals stood and watched the eruption.
"It was spectacular. There were rumbling sounds and thunder and lightning coming out from the base of the eruption," Mr Bennett said.
"It's a volcano. If it goes. It will go. We'll all be vaporised. Ruapehu and Ngauruhoe have erupted regularly over the years. Now it is Tongariro's turn."
He said he considered himself fortunate no rocks landed on his or the other 12 houses on the southern shores of Lake Rotoaira.
Mr Bennett's wife, Robyn, said she had not been able to sleep following the eruption.
"It looked like a huge mushroom cloud. There's a very strong sulphur smell in the air and it was very hard to breath last night."
Mrs Bennett said she and her husband could still hear the mountain rumbling from their home this morning.
"The ash plume is rolling down the side of the mountain. I feel safe and I am not leaving."
'IT'S LIKE AN OLD GIANT FARTED'
Kerry Wakelin, who works for Adventure HQ, said: "I saw flashes and lightning and a big black cloud. I thought it was a big storm."
She had worked at the Whakapapa Ski Field during the major eruptions on Mt Ruapehu in the mid-1990s.
"When Ruapehu blew back then I had my bags packed and was freaking out. Last night I went to bed and had a good night's sleep," Ms Wakelin said.
She reported feeling small earthquakes in the area during the past two days.
"The latest eruption is like a big old giant who has woken up, farted, rolled over and gone back to sleep," Ms Wakelin said.
'I HEARD IT RUMBLING LIKE A TRAIN'
Titahi Bay truck driver Tama Coker was heading across the Desert Road while the eruption was happening last night.
"I thought it was lightning and then it started raining sand. It was pretty thick. I heard it rumbling like a train."
Mr Coker said when he drove through the Desert Rd he could not see the white lines on the road.
"I could just see the yellow glare on the mountain. I only had visibility of about 10 to 15 feet in front of me. It was a bit scary.
"It's something I'll probably never see again in my lifetime."
RESIDENTS TOLD TO CHECK WATER
Police urged residents to check water supplies to make sure they were not contaminated.
There was no immediate health risk to the community and there was no need to remain inside or keep doors and windows closed, police said.
Only people in the local vicinity of the eruption who had a predisposition to respiratory issues were at risk, police said.
Three people were evacuated from Mangatepopo Hut in Tongariro National Park and other huts were still being searched by police and Conservation Department staff.
Tuwharetoa co-ordinator Bubs Smith said 24 people from the settlement were evacuated.
Ruapehu Area DoC community relations officer Bhrent Guy said nobody had stayed in the Ketetahi Hut on Mt Tongariro's northern slopes last night.
State Highway 46 is covered with a thick dark grey paste, just east of the Ketetahi hot springs entrance.
The Turoa and Whakapapa skifields are open.
A thin coat of ash has coated cars and streets in Wairoa, 150km northeast of the eruption.
While no ash has been reported in Napier there have been wide reports of a sulphuric smell.
Inspector Ian Harris, of police central communications, said there had been no reports of injuries or damage because of the eruption and no evacuation notices had been issued, he said.
The Tongariro Power Scheme has been shut down as a precautionary measure.
Some flights to and from Gisborne, Rotorua, Taupo, Napier and Palmerston North have been delayed or cancelled due to the eruption.
Hawke's Bay Airport had suspended all flights.
Wellington Airport is advising travellers to check with their airlines on how the eruption may have affected their flight.
One flight scheduled to land this morning from Gisborne has been cancelled and other North Island flights have been delayed.
An Air New Zealand flight scheduled to leave for Taupo at 11.15am has also been cancelled.
Flights between Wellington and Auckland would probably be unaffected, as they were travelling "well above that plume".
- © Fairfax NZ News
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