November 5, 2012
Volcanic Eruptions Predicted With Satellite Imagery
Brett Smith for redOrbit.com - Your Universe Online
In a new report published in the journal Geophysical Research Letters, two scientists showed they may now be able to detect signs of an impending volcanic eruption by analyzing satellite imagery.Using Interferometric Synthetic Aperture Radar (InSAR) over the active volcanoes in Indonesia's west Sunda arc, the vulcanologists from University of Miami uncovered evidence that showed the ℠inflation´ of several volcanoes prior to their eruption, likely the result of rising magma.
"Surveying entire volcanic regions using satellite data is of primary importance to the detection of ground deformation prior to the onset of eruptions,” said study co-author Estelle Chaussard, a geophysicist at the university. “If volcanic inflation is observed, it can help us to predict where the next eruption may occur. Moreover, 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.”
The over 800 InSAR images of 79 volcanoes used in the study were taken between 2006 and 2009 by the ALOS satellite, part of the Japanese Space Exploration Agency (JAXA) program. The scientists were able to detect signs of inflation at six volcanic centers, three of which erupted after the surveillance period.
Based on their observations and the 0.6-2.0 mile depth of the magma reservoirs located beneath the active volcanoes, the scientists were able to conclude that surface deformation is a common precursor of volcanic eruptions at these locations.
"The notion of detecting deformation prior to a volcanic eruption has been around for a while," said study coauthor Falk Amelung, a University of Miami professor who has been investigating active volcanoes for the past 15 years. "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."
The report added that the depth of these magma chambers correlates directly to the risk for a significant eruption, with a shallow chamber making the eruption event more likely.
The study is significant because it shows the first remotely detected evidence of a precursor to a volcanic eruption, which could be translated into better early warning systems for those living near active volcanoes.
"The monitoring of changes to the Earth's surface helps us to better predict the onset of volcanic activity, which can have devastating impacts on human life," said Amelung. "Like with earthquakes and tsunamis, however, we cannot predict activity with certainty, but we hope that new tools like satellite remote sensing will help us to gather critical information in near real-time so we can anticipate the risk of eruptions and deploy resources in a timely manner."
The scientists said they plan to continue studying the active volcanoes in the region using a newer satellite from JAXA, the ALOS-2, which is scheduled for launch next year. That area of Indonesia is currently home to 13 percent to the world´s active volcanoes.