Although basaltic volcanic systems are particularly acknowledged for producing predominantly effusive activity, these types of volcanoes can also produce explosive activity. Usually these activities occur through the production of lava fountains, such as those produced by Mount Etna. In recent decades this volcano has produced several sequences of lava fountains, also known locally as paroxysmal eruptions. The last sequence began on December 13-14, 2020, and ended on February 21, 2022, producing sixty-two paroxysmal episodes from the South East Crater. This kind of activity is characterized by production of energetic lava fountains, which in some cases reached heightsof 1-2 km above the crater edge. In addition, during these events there is also the production of high eruptive columns, which sometimes rise up to 10-15 km above sea level (asl). The major issue associated with this type of events is the fallout of ballistic particles around the summit craters, sometimes even reaching some of the most touristy areas of the volcano. Considering the frequent occurrence of these activities, it is appropriate to estimate the impact associated with the fallout of these particles. We present in this work field data collected after the lava fountain of February 21, 2022, which produced lava fountains higher than 1000 m above the crater edge and an eruptive column about 10 km a.s.l., directed toward the southeastern side of the volcano. Several large ballistics fell just southeast of the summit craters, in the area of the Barbagallo Craters (at around 2900 m a.s.l.), which is one of the most popular touristic areas on Mt. Etna. After collecting several samples and performing laboratory analysis to derive their size, shape, and density, the values obtained, along with the quantitative analysis of the lava fountain, were compared with results acquired through a and free-available calculator of ballistic trajectories ejected during explosive eruptions, called "Eject! software". We therefore compared the main eruptive conditions occurred during the lava fountain of February 21, 2022 with other data obtained by other remote sensors, including weather data and the relative height of the incandescent jet region (IJR) of the lava fountain during the paroxysmal phase of this eruptive event. However, these paroxysmal episodes occur under widely varying eruptive and meteorological conditions, so we have applied a similar approach to other lava fountains of the 2020-22 sequence (for which large clast fallout has been reported), with different characteristics than the February 21, 2022 event. Thus, knowing the height of the fountain and the intensity of winds, a real-time model could be implemented in the future to assess the impact produced by a lava fountain episode of Mount Etna, in order to mitigate the risk associated with this kind of events, especially to areas densely affected by tourists and hikers.
The 2020-22 sequence of lava fountains episodes of Mt.Etna (Italy): modeling the trajectories of ballistic in the summit area
Costa, Giorgio;Viccaro, Marco
2023-01-01
Abstract
Although basaltic volcanic systems are particularly acknowledged for producing predominantly effusive activity, these types of volcanoes can also produce explosive activity. Usually these activities occur through the production of lava fountains, such as those produced by Mount Etna. In recent decades this volcano has produced several sequences of lava fountains, also known locally as paroxysmal eruptions. The last sequence began on December 13-14, 2020, and ended on February 21, 2022, producing sixty-two paroxysmal episodes from the South East Crater. This kind of activity is characterized by production of energetic lava fountains, which in some cases reached heightsof 1-2 km above the crater edge. In addition, during these events there is also the production of high eruptive columns, which sometimes rise up to 10-15 km above sea level (asl). The major issue associated with this type of events is the fallout of ballistic particles around the summit craters, sometimes even reaching some of the most touristy areas of the volcano. Considering the frequent occurrence of these activities, it is appropriate to estimate the impact associated with the fallout of these particles. We present in this work field data collected after the lava fountain of February 21, 2022, which produced lava fountains higher than 1000 m above the crater edge and an eruptive column about 10 km a.s.l., directed toward the southeastern side of the volcano. Several large ballistics fell just southeast of the summit craters, in the area of the Barbagallo Craters (at around 2900 m a.s.l.), which is one of the most popular touristic areas on Mt. Etna. After collecting several samples and performing laboratory analysis to derive their size, shape, and density, the values obtained, along with the quantitative analysis of the lava fountain, were compared with results acquired through a and free-available calculator of ballistic trajectories ejected during explosive eruptions, called "Eject! software". We therefore compared the main eruptive conditions occurred during the lava fountain of February 21, 2022 with other data obtained by other remote sensors, including weather data and the relative height of the incandescent jet region (IJR) of the lava fountain during the paroxysmal phase of this eruptive event. However, these paroxysmal episodes occur under widely varying eruptive and meteorological conditions, so we have applied a similar approach to other lava fountains of the 2020-22 sequence (for which large clast fallout has been reported), with different characteristics than the February 21, 2022 event. Thus, knowing the height of the fountain and the intensity of winds, a real-time model could be implemented in the future to assess the impact produced by a lava fountain episode of Mount Etna, in order to mitigate the risk associated with this kind of events, especially to areas densely affected by tourists and hikers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
