Experts thought they had the volcano figured out

Jul 26, 2010 10:59 GMT  ·  By

The key to being able to predict when a volcano will next erupt is understanding the inner workings of that specific mountain. While general analysis can be applied to all volcanoes of a certain type, truly precise predictions can only be achieved if experts analyze each mountain individually. When it comes to Italy's Stromboli volcano, most members of the international scientific community believed until recently that they had the mountain figured out. But new data shows that they actually still have a lot to learn, ScienceDaily reports.

This particular volcano has been erupting ever 5 to 20 minutes for several thousands of years. Lava and ash is spewed hundreds of meters into the air, with the molten rock then falling on the edge of the mountain and forming featured known as “streams of fire.” For decades, experts have believed that the eruptions were caused by swimming-pool-sized bubbles of gas. They believed that these features were traveling upwards from the Earth's mantle, passing through layers of magma. It was believed that, when the bubbles reached the surface, they popped, producing the eruption.

A new paper developed by scientists at the Massachusetts Institute of Technology (MIT) shows that this hypothesis may in fact be wrong. In charge of the work was graduate student Jenny Suckale, who is based at the Institute's Department of Earth, Atmospheric and Planetary Sciences (EAPS). She created an advanced computer model of the magma flows underneath Stromboli, which seems to indicate that the previous theory is wrong. Suckale explains that the bubbles could not possible be causing the eruptions, because that would mean they do not respect the basic laws of fluid mechanics.

The experts propose that the Stromboli eruptions are actually caused by a plug-like structure, made out of a material similar to a sponge. Very small bubbles keep rising from the mantle, and accumulate below the plug, exerting increasing pressure on it. Every few minutes, the pressure becomes so large that the obstacle fractures, allowing for some of it to be released. Suckale says that fellow volcanogists who have been living in error for so many years did so because they tended to believe that the motion of bubbles in a volcano is the same as is it in a lab tank, which is obviously not the case.