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University of Canterbury (UC) volcanologists have invented a very expensive super alloy pressure cooker that will help GNS Science better predict volcanic eruptions.
The cooker, a magma brewery, is the brainchild of senior lecturer Ben Kennedy and PhD student Felix Von Aulock.
``It is the first of its kind in New Zealand and better than others that exist elsewhere in the world,’’ Dr Kennedy said today.
``We are a country with a number of active volcanoes and this will significantly help in our research to understand their activity better. We like to know what magma is doing under the crater. Is there any magma? Is the magma rising? Are bubbles growing in the magma? These are the questions that our magma brewery can help with.
``Magma plugs, similarly to corks in champagne bottles, allow pressure to build up in volcanoes. The bubble and gas content are the critical magma properties that control volcano explosivity. However, how these properties develop as the magma solidifies or re-melts remains poorly understood.’’
Our volcano testing machine was built by an independent engineer Pete Jones and in collaboration with the engineering department at UC.
The state of the art high temperature pressure vessel is being used to investigate changes in properties and pressure in rocks from volcanic plugs. The results will be invaluable to hazard mitigation and eruption modelling for volcanic eruptions in New Zealand.
Dr Kennedy said they should be producing data in the next few weeks and carry out ongoing research in the coming years that will be helpful to GNS Science to better predict eruptions.
``The magma we heat gets up to 750degC and we open valves very carefully to release the pressure enough to grow bubbles without explosion, a bit like slowly opening a coke bottle. We do everything up to the point of an explosion.
``We have samples from our Magma Brewery and from White Island that we then explode in Munich, Germany, on a similar machine. We hope to get samples from Tongariro as soon as it is safe to go up there. It’s really ground-breaking stuff.’’
Dr Kennedy is working with Tom Wilson studying the Tongariro eruption on August 6.
`The ash from that eruption was the most electrically conductive they had ever seen, so it would be really nice to produce some in the lab,’’ Dr Wilson said.
``Given the thickness of ash which fell on the power lines, it must have come close to causing a flashover (short circuit).’’