[Benjamin]

The hot crater lake on White Island has now completely dried up as explosive rocks, mud and gas continue to be thrown into the air from the active volcano.

White Island has been spewing a steady stream of gas since activity heated up in December. It's the most active the volcano has been since 2000.

GNS Science vulcanologist Brad Scott said a "small tuff cone" was forming on the bottom of the crater lake, and the active vent was producing "vigorous bursts" of mud, rock, steam and gas up to 100 metres into the air.

"GNS Science's past monitoring of the island shows that new eruptive episodes often develop out of this type of activity," Scott said.

"Small muddy lakes sometimes form in craters. As the unrest develops geysering and explosions occur through these lakes, becoming more vigorous with time."

He said the activity did not necessarily mean an explosion or full-scale eruption would happen, although one could at any time.

Even though there was an elevated risk to tourists on the island, conditions weren't so dangerous that people could not travel there.

Tourism has, in fact, been booming at White Island as the volcano heats up, with visitors eager to see some explosive action.

Frontier Helicopters is one of three helicopter tour operators which fly around the island.

Owner Mark Law said there had definitely been a greater interest in the activity from visitors lately.

"It is our busy season, so it's a little hard to gauge whether or not more people are coming to visit the island because of it, but there is a greater awareness about the island from tourists, definitely," he said.

Law said company worked closely with GNS to assess the safety and in a worst-case scenario – a full scale eruption – it would simply mean they would not be able to fly as close.

"The only thing is, if it gets to any serious level of activity there's an exclusion zone which we operate by, because you can never tell just how far it will throw rocks," Law said.

At this stage, it was still possible to get reasonably close to the crater.

One of the pilots from Frontier was able to get about 180 metres away to film some spectacular footage of the explosions on Monday.

http://www.stuff.co.nz/science/82414...medium=twitter

Cool little video on the site.