By Simon Shepherd
A new early warning radar has been set up at Mount Ruapehu to help provide immediate notice of an eruption or a lahar.
The technology's installation comes as the temperatures in the crater lake rise, and scientists say they want to be ready for a possible eruption.
"We knew that Ruapehu was going to awaken sooner or later," says volcanologist Gert Lube. "So it would be good to have something that could measure volcanic eruptions directly."
With help from colleagues in Germany, volcanologists have installed a radar dish on Mount Ruapehu's Whakapapa skifield. The device sends out a pulsed beam, which can instantly measure the speed and size of particles that thrown our during an eruption.
"Through this we should be able to tell the energy of the explosion," says volcanologist Shane Cronin. "We should be able to calculate how large eruptions might be, how large eruption columns might get, and what sort of ash fall we might get from them."
Current warning systems measure seismic activity and shockwaves sent out by an explosion. But if the weather is bad, no one can see what exactly is going on.
Volcanologists already use radar technology on the most active volcanoes around the world, such as Mount Stromboli on the Italian island of Sicily.
However scientists need Mount Ruapehu to rumble one more time to be sure its new radar is pointed in the right direction.
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