Thursday, December 07, 2006
Better technology could help with prediction of volcano eruptions
Dr. Alina Hale from the Earth Systems Science Computational Centre at the University of Queensland and colleagues have been investigating a type of repetitive earthquake that typically occurs before volcanic eruptions."Quite often these long-period earthquakes are observed before a volcano does something nasty. It's basically an indication that something's going to happen, but no-one has actually worked out how they occur," said Dr. Hale.
Recently, scientists have begun to think the quakes may be caused by areas of instability in volcanic lava called shear bands. But until now there has been no accurate way to explain the connection."It's been eluding us exactly what the volcano is trying to tell us with these signals. People have had a go at trying to correlate shear bands with these earthquakes, but so far it hasn't been convincing," she said.
Speaking at the Australian Institute of Physics conference Brisbane, Hale described how the new model incorporates processes such as the formation of crystals in lava to make the correlation more precise."It was a case of putting two and two together to pinpoint how these signals are being generated," said Dr. Hale.Dr. Hale used real-world data from Soufrière Hills Volcano, which devastated the island of Montserrat, to show that her model confirmed that shear bands were being generated at the depths where long-period earthquakes occur."
We're now getting closer to understanding where and why these signals occur. Basically it could potentially give us the ability to predict eruptions. But, more research needs to be done to further refine scientists' understanding of the processes behind long-period earthquakes," she added.