for National Geographic magazine
What are the secrets of a volcanic eruption? A few hundred courageous scientists around the world are trying to figure out the answers, often at great personal risk.
One of them, geologist Michael Ramsey, has spent 12 years investigating volcanic behavior, and is now using thermal infrared technology and data from NASA and weather satellites to determine when and how violently volcanoes will erupt—research that will help to save lives.
Thermal infrared imaging, which captures pictures of radiated energy invisible to the human eye, helps scientists like Ramsey track potentially deadly patterns of heat in and around some of the world's 1,500 active volcanoes.
(See more photos of volcanoes.)
Data gleaned from these images can already alert them to volcanic activity before it becomes dangerous, and may one day help them better forecast eruptions.
"Ten percent of the global population lives underneath active volcanoes," says Ramsey, an associate professor at the University of Pittsburgh. "This is an issue that affects people around the world."
The View From Space
On high-resolution images shot by satellites circling our planet, active volcanoes stand out like lights on a Christmas tree. They glow bright white as they ramp up for an eruption, and the speed with which they cool down can tell scientists much about their geological composition, which in turn helps them predict whether the volcanoes will erupt violently.
With funding from the National Geographic Society's Committee for Research and Exploration, Ramsey and his research partner, geologist Adam Carter, were able to fine-tune information they received from the Earth-imaging ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor on NASA's Terra satellite by cross-referencing it with ground samples and images Carter collected at one of 29 active volcanoes on the Kamchatka Peninsula, in far eastern Russia.
In the days leading up to an eruption, Carter used a handheld infrared camera known as the FLIR (Forward Looking Infrared Radiometer) to capture color images of the Bezymianny volcano's lava dome and ash deposits on its flank, as well as record their surface temperatures.
"Bezymianny is remarkably punctual," Carter says. "It typically erupts twice a year. We wanted to track it and see if there were any warning signs."
As it turned out, there were. Poring over their data, Carter and Ramsey were able to identify a thermal precursor signal—a crucial moment four days before a December 2006 eruption when ASTER's data showed the temperature in the lava dome had shot up by at least 68 degrees Fahrenheit (20 degrees Celsius).
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