After a private overflight conducted Tuesday, the teacher-researcher at the University of Colima Nick Varley, was able to see something he foresaw few days before through Mexico Webcams: a small lava dome growing in the crater of the volcano of Colima.
A week earlier, he no longer saw the night glow in the crater, “something that can not be explained by the emergence of fresh magma”. So to learn about the situation, he and several of his students have paid a flight to the volcano’s crater to observe directly whether he had a new dome or not.
Since July last year, the common behavior of the volcano’s eruptions were explosive, no magma buildup.
The scientist from the University of Colima explains, in a broad sense there are two types of eruptions: effusive and explosive. In the effusive case, magma, passively, is in the form of a viscous liquid, something like toothpaste. This magma reaches the surface slowly forms a dome that can then fill the crater, and under its own weight with the help of gravity, it overflows and slips on the flanks of the volcano.
In explosive eruptions, the most important are the gas. With them, the output is more violent than passive. Magma comes out, but also with ash and rocks (called “ballistic” by experts), although with the distance, we can see only ashes.
With this flight, they could see that there is a small dome, about 25 meters in diameter and 10 high, which is still low in a crater about 300 meters in diameter. In addition, they noticed a point of the dome, with the thermal imaging camera, or there are temperatures of 700 degrees Celsius. This measure, if asked directly, he said, would be The hottest area in the crater measured when hovering there a month ago, he said, corresponds to that which has been “invaded” by the new dome. In addition, the current crater, said Nick Varley, is deeper than in previous years. “This means it will take longer to be filled with magma.”
The new dome, has he said, “marks a new episode of the effusion, and it is important to be aware of, because if we increase its growth rate, it could increase the possibility of another collapse, as in July last year, which would create a potentially hazardous situation. “
A rough estimate has he said, the growth rate of the dome would be 0.02 cubic meters per second. But to get a more exact value, other measures are needed, because the growth of a dome can be up to 10 cubic meters per second.
February 20 , 2016. Colima , Mexico :
Source : Ucol.mx