An Italian-led study has revealed that nanocrystals that form in magma when there is a high amount of titanium and iron make the magma denser and cause the formation of bubbles, two elements that lead to explosive eruptions
New mysteries revealed in the heart of the subsoil that show important mechanisms in the complex and fascinating phenomenon of eruptions – and in particular of explosive eruptions.
A new discovery indicates that at their origin, in volcanoes such as Etna and Stromboli, there are nanocrystals up to 10 thousand times smaller than a human hairwhich are formed in magma when present a high amount of metals such as titanium and iron.
their presence makes the magma denser and causes the formation of bubblestwo elements that favor explosive eruptions.
The news comes from a prestigious source, an international study published in the journal Nature Communications Earth & Environment led by Italy, with the University of Roma Tre and the Institute of Environmental Geology and Geoengineering of the National Research Council (Cnr-Igag).
What exactly happens? She explains it Alessandro Vona of Roma Tre University, one of the authors of the study led by Alex Scarani: The basaltic type magma, which differs from the granitic one because it goes up to the surface instead of solidifying inside the earth’s crust, typical of volcanoes such as Etna and Stromboli and usually does not produce explosive eruptions. However, explosive events are occasionally observed at basaltic volcanoes, generating a heated scientific debate about their causes.
Our work, Vona continues, demonstrates that minimal differences in magma composition can lead to the formation of nanocrystals during its ascent which increase the viscosity and trap gas bubbles.
Researchers are working to link observations made in the laboratory with those in the field at volcanoes around the world.
According to Danilo Di Genova, a researcher at the Institute of Environmental Geology and Geoengineering of the National Research Council (Cnr-Igag) who coordinated the study together with Alessandro Vona, this study represents a further step towards a better understanding of the molecular structure of magmas, which plays a key role during volcanic eruptions.
The results obtained with this study invite the Earth sciences to a critical and systematic review of the data available so far on magma, argues Alessio Zandon of the French University of Orlans, co-author of the study. Zandon comments: These crystals, so small as to be almost invisible if not studied with the right instrumentation, can significantly alter the viscosity.
And as the volcanologist and scholar of the history of Etna Salvo Caffo underlines: By studying volcanoes we analyze the secrets of life on Earth and in the subsoil. Volcanoes are at the origin of life, and through them it is also possible to study the long duration of geological times.
December 3, 2022 (change December 3, 2022 | 21:26)