Sensor provides volcanic data

Harry Pinkerton, professor of Physical Volcanology and head of the Environmental Science Department at the University of Lancaster is analysing the rheological properties of molten lava. This information will be used to create realistic models of lava flows, which will then be used to predict the final lengths and advance rates of lava flows on volcanoes. The models will also be used to analyse the way that giant lava flows on Earth and other planetary bodies are formed. According to Prof Pinkerton, this has important implications for the current debates on factors that caused major climate changes in the geological record. The research will also help minimise damage during future eruptions, and will be directly transferable to research relating to Mars and other planets where volcanic activity is prevalent. The research has been conducted with equipment he has developed based on a high performance torque sensor developed by Oxfordshire based Sensor Technology. Prof Pinkerton said: "We sink a paddle into a lava flow, drive it at different speed from 0.1 to 60rpm and record the lava's resistance to movement on to a pc." It is not just the speed that is varied, but also the depth of penetration into the lava. This procedure is then repeated several times at different locations in the lava flow to build up a detailed mathematical model of the actual flow. All the sensing and data capture is done through a Torqsense unit, which is robust enough for such arduous fieldwork, yet sensitive enough that it can detect the slightest change in dynamics. It is a non-contact transducer that uses surface acoustic waves to create frequency dependent strain gauges to measure the change in resonant frequency in the paddle's drive shaft as it is subjected to strain. This measurement is directly related to the torque, a key parameter in Prof Pinkerton's analysis – and in many industrial control situations where its unique technology and variety of outputs can offer significant advantages. "The simplicity of the Torqsense technology makes our field work possible," added Pinkerton. "It's an Olympian feat to lug masses of equipment up a Mediterranean mountain and into a seeringly hot lava field. You want to be confident that everything is going to work no matter how many hours you stay there."