Earthquakes: deep magma source found under the Apennines
In the Southern Apennines there is a deep source of magma the ascent of which could generate earthquakes of significant magnitudes and deeper than the seismicity typical of this area.
This is what emerges from a study carried out by researchers at INGV and the Department of Physics and Geology of the University of Perugia, published in the journal Science Advances. The study also developed models useful for the identification of signals attributable to magma ascent in the world’s major mountain ranges, such as the Alps, the Himalayas and the Andes.
The Italian study analysed an anomalous seismic sequence that occurred in December 2013 in the Sannio-Matese area, with magnitudes up to 5. “We discovered that these earthquakes were triggered by magma ascent in the crust at depths between 10 and 25 km”, explained Francesca Di Luccio, INGV geophysicist, who coordinated the study together with Guido Ventura. According to the researcher, this event is anomalous compared to earthquakes in this area and to seismic events in volcanic areas.
The data collected by the researchers have demonstrated that the gases released by this magma intrusion were mainly made up of carbon dioxide, which reached the surface as free gas or dissolved in the aquifers of this Apennine area. “This result”, added Guido Ventura, INGV volcanologist, who contributed to the recent discovery of a chain of submerged volcanoes in the southern Tyrrhenian Sea, “opens up new avenues for the identification of the magma ascent areas in the mountain ranges and highlights the fact that such intrusions can generate earthquakes with significant magnitudes”.
According to the researchers, the study provides new knowledge of the evolution mechanisms of the earth’s crust and for the interpretation of the seismic risk associated with deep magma in mountain ranges.