A multidisciplinary analysis of the February 10, 2022 event published in Nature Communications Earth & Environment
An integrated and multidisciplinary approach has allowed a team of researchers from theNational Institute of Geophysics and Volcanology (INGV) to reconstruct the dynamics that led to the formation of a Pyroclastic avalanche on Etna on February 10, 2022. A systematic review “Trigger mechanism and propagation dynamics of pyroclastic density currents at basaltic volcanoes”, conducted by researchers from the Etna Observatory and the Pisa section of the INGV, was recently published in the scientific journal Nature Communications Earth & Environment.
Pyroclastic avalanches, also known as pyroclastic currents, are high-speed flows consisting of hot gases, ash and volcanic fragments. These are among the most dangerous phenomena in volcanic environments, capable of developing suddenly and rapidly covering large portions of the flanks of the volcanic edifice. The event under study was generated in correspondence with a fracture that opened on the southern flank of the cone of the Southeast Crater (CSE), during a particularly intense eruptive phase.
“The integrated analysis of ground-based observations, video recordings, satellite images, petrographic data and numerical models has highlighted how the rapid accumulation of unstable material, combined with high residual temperatures and alteration of surface deposits, led to a gravitational collapse of the cone flank”, declares Daniel Andronicus, researcher at INGV and co-author of the study.
The resulting pyroclastic flow involved a volume of about one million cubic meters of material, propagating up to the area of the craters formed during the 2002-2003 eruption, an area of frequent hiking interest. The event left a deep scar on the CSE cone, also visible in satellite observations.
Numerical simulation of the 2022 event suggests that the avalanche propagated with a high kinetic energy determined not only by gravitational collapse, but also by the onset of processes that favored its high mobility, including the progressive fragmentation of the material during the descent and the expansion of hot fluids from the body of the cone.
“The calibration of the numerical model has also allowed us to produce an updated hazard map for the summit area of Etna, useful for supporting decisions regarding tourist access during eruptive phases”, points out Francesco Zuccarello, INGV researcher and co-author. “It is a fundamental tool to strengthen prevention and risk management in a constantly evolving context”.
Just a few weeks ago, on June 2nd, a new pyroclastic avalanche occurred on the north-eastern slope of the CSE, which formed a deposit extending up to almost 3 km away, confirming the results obtained from the hazard map and the importance of these studies in supporting civil protection for the protection of hikers and workers operating in the summit area.
The work is part of the activities of the PANACEA project – Dynamic Planet, funded by Ministry of University and Research (MUR), and constitutes an important contribution to the understanding of the mechanisms that can trigger potentially dangerous events in active volcanoes, with operational applications in hazard assessment and emergency management.
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National Institute of Geophysics and Volcanology (INGV)
Photos - INGV researchers at work to study a stratigraphic section on the pyroclastic avalanche deposit