Etna has a new peak: it has become taller

The cause was about 50 eruptions since February 16, 2021 in the Southeast crater. The new height record is 3,357 meters above sea level and its shape has also changed.

Etna is growing, has become higher and has a new peak. This was revealed by the National Institute of Geophysics and Volcanology, which reported the new height record that touched 3,357 meters above sea level. The cause was the approximately 50 eruptions that since February 16, 2021 have affected the Southeast crater. During these paroxysmal events, significant amounts of pyroclastic material and lava layers accumulated on the cone of the Southeast Crater, the youngest and most active of the volcano's four. This has also led to a transformation of Etna's outline and the formation of a new peak.

Etna's new height and peak

Satellite image processing has shown that the Southeast crater has surpassed the Northeast crater, which for 40 years has been considered Etna's peak. The figure has an uncertainty of 3 meters and was obtained through the processing of two triplets of images from the Pléiades satellite captured between July 13 and 25, 2021, as part of the international partnership Geohazard Supersites and Natural Laboratories.

The two sets of satellite images, produced at a spatial resolution of 1 meter, were aligned with each other and compared with a digital surface model from 2015. After overcoming some problems for the correct topographic reconstruction of the area, the obtained digital model showed that the highest point of the volcano is on the northern rim of the Southeast crater at 3,357 meters (+ or - 3 meters). To locate the new summit, the cloud effect and the plume of gas emitted from the summit craters were eliminated and the model derived from the acquisition of 25 July was integrated with the model derived from the acquisition of 13 July for the southeastern portion covered by gas in the summit area.

The summit of Etna has always been considered the Northeast crater that, with the eruptions of September 1980 and February 1981, had reached the maximum height of 3,350 meters. Over the years, the peak has lowered due to the collapse of its edges until it reached 3,326 meters, according to surveys made in 2018. At 3,357 (or at a minimum 3,354 meters), the summit of the Southeast Crater has currently taken the record away from its "big brother" and, should the paroxysmal events continue, it may even continue to grow.

A team of American chemists has instead identified a substance in the volcanic activity that led to the most important mass extinction in history that could clarify what caused the great devastation at the end of the Paleozoic.

Stefania Bernardini