SCIENTISTS will continue to monitor Mt Tongariro closely following yesterday’s “small scale” eruption.
The volcano came to life at 11.50pm (NZ time) yesterday, sending rock and ash a kilometre into the air and causing threat warnings across the central North Island.
The ash cloud from the eruption is quickly moving east and out of New Zealand.
It was the first time since 1897 it had erupted, GNS science said.
While there had been no escalation in background seismicity today, it could still blow depending on what was causing the unrest, GNS Brad Scott said at a press conference in Taupo.
”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,” Fairfax NZ reported.
”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 would determine what is causing 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.”
Checks of all huts and tracks around Mt Tongariro had revealed no injured or dead people, Conservation Department Ruapehu-Whanganui area manager Nic Peet.
The Ketetahi hut was significantly damaged.
”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.”
Three men who were at the Mangatepopo hut, which was not in the volcanoes firing line, walked out safely.
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, but the rest of the national park remains open.
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.