As the Icelandic volcano that shut down European airports for a week last month continues to calm down, attention has turned to a neighboring mountain that is potentially much more devastating.
From his lab in Oakland, University of Pittsburgh volcanologist Michael Ramsey is helping to monitor the situation by aiming a thermal infrared camera on a NASA satellite at the volcanoes, providing data crucial to understanding what is going on and what might happen.
With the Eyjafjoll volcano cooling down -- a fact in part confirmed by the thermal images -- "the most critical thing right now is watching the other volcano and making sure there's no hot spot there," said Dr. Ramsey, who is the director of Pitt's Image Visualization and Infrared Spectroscopy Laboratory.
The other volcano is Katla, named after a mythical Icelandic witch and located about 25 miles east of Eyjafjoll. Katla has a well-recorded history of massive eruptions on a scale at least 10 times larger than Eyjafjoll, including eruptions that have altered global climate.
More important to Dr. Ramsey's work, the last three times that Eyjafjoll erupted -- in 1821, 1612 and 920 -- Katla followed shortly thereafter with an eruption of its own, lending at least a theoretical hint of when it might erupt next in a field where making predictions can be dicey.
"Based on the geological record, when one goes, the other does, too," Dr. Ramsey said. "And when it does, Katla generally does the exact same thing, but on a scale multitudes larger. That's what we know."
So it's just a matter of time before Katla erupts?
"Potentially," is as far as Dr. Ramsey will go.
When Eyjafjoll began erupting in March, Dr. Ramsey and a team of scientists charged with monitoring NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on the satellite redirected it to take infrared images of the area around the two volcanoes.
The instrument's sensors are sophisticated enough that it not only tells how hot the volcanoes are, it can measure the presence of objects in the sky above the ground, such as ash or steam, and on the ground, such as lava. From that, scientists can say how much gas, rock, ice, water, ash, sulfur dioxide and lava is coming out of a volcano, which is crucial to understanding its activity.
The images -- which can be seen on the website http://www.pitt.edu/~mramsey/data/iceland/ -- showed Eyjafjoll heating up in the first image on April 1, but nothing going on with Katla. By April 17, three days after it began major eruptions and European airports had been shut down, a massive plume of ash can be seen emanating from it. But by April 19, the images showed a cooling of the volcano, as did images from this Monday, and still no change in Katla.
"So far, she seems to be pretty quiet, but we will watch it for several more months at least before we can say it's not going to go," he said. "But if you look at the history there, it's three-for-three that when one goes, the other follows."
Scientists on the ground in Iceland, who were unable to get close enough to use hand-held thermal cameras themselves, were excited to have the data.
"They have been very helpful," Sigurour Kristinsson, a geologist with the government-run Iceland GeoSurvey institution, said in a phone interview.
This weekend Mr. Kristinsson hopes to be able to get close enough to Eyjafjoll, perhaps within three miles of its crater, to take hand-held, thermal readings on Sunday, the same day ASTER will be taking its next images. Combining the ground readings with ASTER's aerial readings will give an even more complete picture of what is happening there, and maybe tell them more about what might happen with Katla.
He isn't sure that Katla will soon erupt because it's "a very old volcano and hasn't erupted in many years and it might be going into a dormant phase," Mr. Kristinsson said. "But if it goes, it will be a much bigger eruption than what we've seen recently."
Sean D. Hamill: firstname.lastname@example.org or 412-263-2579.