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Scientists have recreated conditions found in an erupting volcano in the laboratory, offering a new way to understand and forecast future damaging eruptions.
Using rock from Sicily's Mount Etna they found that small-scale simulations of volcanic activity could be scaled up and related to real events, with fractures of 50 mm (2 inches) in the lab corresponding to faults of about 200 metres in nature.
Active volcanoes produce a mix of seismic signals or small earthquakes that can indicate an eruption, but interpreting their significance is notoriously difficult.
So the capacity to analyse these signals under laboratory conditions and understand how they are caused by water, steam, gas or magma rushing through cracks in rock is a significant step forward.
Philip Benson of University College London and colleagues reported their findings in the journal Science.
They reproduced the stresses found inside a volcano by forcing water through drilled cylinders of basalt, at pressures typically found 2.5 km (1.6 miles) underground, and then released it suddenly.
"We can better forecast eruptions and the different cycles of eruptions with better time accuracy as we understand more about the physical mechanisms that go on," Benson told Reuters.
Luigi Burlini of the Institute of Geology in Zurich and Giulio Di Toro of Italy's University of Padua said such experiments made it possible to study stress mechanisms separately — effectively allowing scientists to identify different "instruments" in the seismic "orchestra".
"This understanding should allow for better predictions of the intensity and timing of volcanic eruptions, so that early warning and alerts can save lives," they wrote in a commentary in Science.
Separate research on the Soufriere Hills volcano on the Caribbean island of Montserrat suggests volcanoes are in fact even more complex than expected. ■Reuters
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