Kamchatka, a remote peninsula in northeastern Russia, is home to the world’s most explosive volcano. In the journal Contributions to Mineralogy and Petrology, researchers examined small nodules of primitive magma that were erupted and preserved among other materials.
The Kamchatka volcano Shiveluch has experienced more than 40 powerful eruptions over the past 10,000 years. The last giant eruption occurred in 1964, as a result of which a new crater was formed and covered an area of almost 100 km² with pyroclastic flows. But at present, Shiveluch is erupting in the same way as it was 20 years ago.
Researchers at the University of Washington in St. Louis set out to understand what makes Shiveluch erupt, it will help study the global water cycle and gain insight into the aquatic systems of other volcanoes.
“The minerals in these nodules retain traces of early magma evolution, deep in the earth’s crust.”
Andrea Goltz, PhD student at the Department of Earth and Planetary Sciences in Arts and Sciences
The researchers found that the conditions inside Shiveluch included about 10-14% water by weight. Most volcanoes contain less than 1% water. For volcanoes in the subduction zone, the average value is usually 4%, rarely exceeds 8%, and such a volcano is considered superaqueous.
The only way to get primitive, pristine materials at low temperatures is to add a lot of water. Adding water to the rock has the same effect as adding salt to ice – it lowers the melting point. In this case, there is so much water that the temperature drops to the point at which the minerals crystallize.