The eruption of Etna is finished which in the day of yesterday produced one burning cloud from the South-East crater and the formation of Three lava flows Main: one directed to the south, a second to the east, branches out in more arms, and the last one, originating at the base of the northern side of the southeast crater, headed to the north. Already on the evening of June 2, the INGV had updated the alert by bringing it back to the yellow level: theStrombolian activity had been recorded in decrease, with only one weak emission of ashes.
But the highest volcano in Europe, among the most active in the world, is also at the center of the recent study Pressurized Magma Storage in Radial Dike Network Beneath Etna Volcano Evidenced with P-Wave Anisotropic Imagingpublished in the magazine Communications Earth & Environment and conducted by a team of researchers from Department of Geosciences of the University of Padua coordinated by Gianmarco del Piccolo And Manuele Factory: analyzing the seismic wavesin fact, the researchers managed to map the structure of the magmatic system that exists below Monte Etna, thus managing to explain how the magma escapes from summit craters and from lateral mouths of the volcano.
What the study on the lifts of the Magma of Etna states
The Etna, therefore, can also erut laterallythrough cracks present along the sides of the volcano, and not only by summit craters. But why does this happen? The study managed to demonstrate the existence of a network of “dici vertical», That is, some fractures filled with magma which extend between 6 and 16 km deep. It is precisely these fractures that have formed one Radial network, which in turn gave rise to a system of “preferential ways” for the ascent of the magma: this explains why the eruptive activity of Etna takes place from the summit craters and the side mouths on the volcano. According to observations, a deep magmatic system, characterized by high pressure pressures.
In the map below, taken from the study, there is clearly the radial distribution of the dicchi in the volcanic subsoil.
How the map of the internal structure of Etna was built
In particular, the team of researchers used a particular seismological techniqueor the “Seismic tomography “: it is a geophysical investigation method that allows to obtain detailed subsoil images thanks to theanalyses of the propagation of seismic waves In the subsoil, whose behavior depends on the physical properties of the material they cross on which a “3D map” can be indirectly reconstructed of how the interior of the volcano is made. The seismic waves, in fact, change based on the type of material they cross: in the case of fractures in the rock, for example, the seismic waves will tend to spread more slowly along certain directions related to those of the fractures themselves.
Based on a probabilistic approach, the researchers managed to analyze beyond 37,000 seismic signalscollected between 2006 and 2016 under Etna, thus realizing a sort Tac “of the volcano thanks to the use of seismic waves instead of the classics X -rays. By collecting this data you can trace thearchitecture of the volcanic plant (and consequently to migration paths of magma) because this is related to the so -called “elastic anisotropia»(The property of a material to present different behaviors depending on the direction along the elastic stresses) which are closely linked to the state of stress of the crust, That is, the state of solicitation to which the crustal rocks are subject, which is deductible from the propagation maps of the seismic waves.
Because this study is important
In other words, the developed method could lead to more reliable predictions of the preferential streets where the magma and fluids in crustbut also to a greater one comprehension of the effect of the stress in crustal environments In seismic areas, geothermal fields or oil fields. The technique used, among other things, also allowed to evaluate the degree of uncertainty of the results, thus making the simulations of the paths of the magma through the crust, with consequent implications for the evaluation of the volcanic danger.
Unfortunately, however, this new knowledge is not enough to directly predict how and when the future Etna eruptions: the forecast of volcanic eruptions is extremely complex and currently represents a still open field of research.
