New research suggests super-volcanoes can erupt spontaneously without the need for an external trigger such as an earthquake.
Supervolcanic eruptions can change the entire climate of the earth. Two new studies published in the journal of Nature Geoscience have said that such cataclysmic events can occur spontaneously and do not need any triggers to set them off such as an earthquake.
According to an experiment at the European Synchrotron Radiation Facility (ESRF) in Grenoble, the difference in the density between magma and the surround rocks in these super-volcanoes is enough to tear open a huge crack in the earth’s crust per Nature World News.
Super-volcanoes differ from average volcanoes in that they do not actually erupt; they “explode”, tearing a massive hole in the earth’s crust. Before, it was assumed that earthquakes could be connected to these eruptions.
Researchers at ETH Zurich have now been able to determine using X-rays from ESRF the density of the magma. They used the latest technique to artificially produce magma melts under different temperature and pressure conditions. Researchers accounted for differing water content in the magma melt. The team then constructed mathematical models to explain the conditions in a supervolcano.
“Until now, nobody had measured the density of the magma that is present in the magma chambers of super-volcanoes,” EZH’s Wim Malfait told AFP. “Magma is less dense than solid rock, the magma in a magma chamber pushes on the roof of the chamber.”
In a different, separate study on the subject, researchers at the University of Geneva and their colleagues found that buoyancy of the magma is important in the supervolcano explosion.
“It is comparable to a football filled with air under water, which is forced upwards by the denser water around it,” lead author Wim Malfait of ETH Zurich explained in a news release.
The good news is, although super-volcanoes can erupt spontaneously, they rarely happen, usually every 100,000 years or so.