An unexpected volcanic eruption in Nicaragua this past September forced officials to evacuate thousands of people. Events like this threaten people and crops around the world every year, and even close airports. But what if scientists could predict when a volcano is about to blow? Could some of this chaos be avoided?
Scientists already have a few ways to monitor active volcanoes, but they usually require the placement of sensors near or in the dangerous areas to measure for vibrations or changes in gases such as carbon dioxide or sulfur dioxide. But not every government has the ability to monitor all of the volcanoes within its borders.
Now a new solution has arisen: satellites. Scientists at the University of Miami's Rosenstiel School of Marine & Atmospheric Science have proven that satellites can measure the ground around volcanoes to look for changes over time. When the ground "inflates" due to rising magma beneath the surface, the satellites can see the difference. Their work is pending publication in the journal Geophysical Research Letters.
"If volcanic inflation is observed, it can help us to predict where the next eruption may occur," said geophysicist, PhD student and the study's co-author Estelle Chaussard. "In regions like Indonesia, where volcanoes are prevalent and pose a threat to millions of people, and where ground-based monitoring is sparse, remote sensing via satellite could become a major forecasting tool."
Chaussard and co-author Falk Amelung, an associate professor of marine geology and geophysics, used a technique called Interferometric Synthetic Aperture Radar (InSAR) to study 79 active volcanoes in Indonesia's west Sunda arc between 2006 and 2009. The data, which generates maps of surface elevation, showed that the three volcanoes that erupted during this time inflated prior to exploding.
"The notion of detecting deformation prior to a volcanic eruption has been around for a while," Amelung said in a press release. "Because this region is so volcanically active, our use of InSAR has been very successful. We now have a tool that can tell us where eruptions are more likely to occur."
Amelung said this new technique does not allow 100 percent certain prediction — three other volcanoes in the area "inflated" during the period but did not erupt — but it could provide real-time information to help anticipate future volcanic events.
Chaussard and Amelung plan to continue their research by looking at other parts of Indonesia, as well as the Philippines.
Volcanologists aren't the only people who are improving their research with InSAR satellite data. Amelung co-authored another paper this past September, also in Geophysical Research Letters, that examined the 2008 earthquakes in the Reno basin to determine that they were caused by a slip in a previously unrecognized fault line.
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