Mr Frew said he took some comfort from the 10,000-year-old podocarp alpine forest on the western side of Mt Ruapehu that still stands today.
Ohakune was still "a long way away" from Mt Ruapehu, he said, and during the 1996/97 eruption, there was only one night where they saw any of the activity, and that was spectacular. There was only slight ash fall from the north.
However, Mr Frew said his mother had told him that during the 1945/47 ash eruptions there were significant ash falls over the Raetihi/Ohakune area.
The ash is an incredibly heavy material and wreaks havoc because of its corrosive properties, said Turangi man Brian Gurney, who was visiting Ohakune.
Mr Gurney told the Chronicle the 1996/97 eruption cost him a new roof. But because it was five years after the eruption that he noticed the corrosion, the insurance company would not pay because he had not put in a tentative claim at the time.
"The ash had gone in under the lap of the roof and corroded the downpipes and spoutings," he said.
But this time he knows the damage ash can cause. He is also ready with a wheelbarrow and shovel and his wife has stocked the essentials such as toilet paper.
Visit Ruapehu Trust general manager Mike Smith said there was a 2km safety zone around Mt Ruapehu's summit.
School groups held outdoor education in geography and science at this time of the year, but he had not heard of any cancellations.
He said November was the "shoulder season" between the end of the ski season and start of the summer activities that were growing in the region with the bike and walking tracks development, but they had not yet noticed extra people coming to the area.
Ruapehu District Council staff throughout the organisation were on "general readiness" and trained in civil defence response, which is a legislative requirement. Council communications manager Paul Wheatcroft said Mt Ruapehu was an active volcano and the alert was always at level 1.
In determining risk, staff were issued with goggles and dust masks.
He said the mountain was "bubbling along" and there had not been a change in status.
Ohakune iSite manager Ken Hill said they had had a few inquiries, and posted the latest information about any mountain activity for visitors who came in to the town.
At the Winstone Pulp mill at Karioi, the technical manager Gustav Ban said an internal precaution had been issued to all staff to not go into or near the Whangaehu River.
Recent measurements at Ruapehu indicate that the likelihood of an eruption has increased, GNS Science said.
Volcanologist Nico Fournier said GNS was monitoring the Crater lake 24/7 with instruments on the mountain and flew to the crater, where they suspended a bucket to gather a water sample, which was then sent to laboratories at Wairakei and Wellington.
On November 16, the scientists reported that the temperature beneath the crater lake was about 800C but the lake itself only 20C, which did not give any immediate warning there would be an eruption. The temperature suggests the vent is partly blocked, which may be leading to a pressure build-up beneath the crater lake.
There is a heightened likelihood of eruptions over the coming weeks to months.
"Since late October, small earthquakes have been occurring about 5km beneath the summit area of Ruapehu, but these may not be directly related to the high temperatures beneath crater lake as they are much deeper."
