A study recently published in Remote Sensing characterized the "hidden" eruption of Etna, identified by the INGV monitoring system but made invisible by the clouds
A volcanic eruption occurred during a snowstorm at the end of May, which generated a pyroclastic flow remained "unnoticed" for about 10 days, until the weather conditions improved and researchers were able to access the summit areas of the volcano.
It might seem like literature but that's what happened last year May 21, 2023 on 'Etna, as described in the study “A Hidden Eruption: The 21 May 2023 Paroxysm of the Etna Volcano (Italy)” created by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV),Sapienza University of Rome,University of L'Aquila and University of Cagliari.
“Our work, in addition to scientifically describing the eruptive event that affected the South-East crater of Etna, wanted to draw attention to the importance and effectiveness of the INGV remote monitoring systems”, explains Emanuela De Beni, volcanologist ofINGV Etna Observatory (INGV-OE) and co-author of the study. “In fact, although the bad weather had obscured the video surveillance cameras installed on the volcano, the other volcanological monitoring stations worked correctly and the signals promptly arrived at our Operations Room in Catania, signaling to us that aneruption with lava fountain and emission of two flows, one towards the South and the other towards the East”.
A week after the eruption, INGV researchers went to the summit area to carry out surveys with drones and proceed with the mapping and quantification of the erupted products.
“Once we arrived on site we realized that a deposit that we had not been aware of until then had actually overlapped the southern flow", goes on De Beni. “After careful soil investigations and sedimentological analyzes we discovered that it was a 'pyroclastic current of density (PDC - Pyroclastic Density Current), i.e. a flow of magmatic material mixed with gas at high temperatures that had descended at high speed from the flanks of the volcano".
At that point, the field and drone surveys were accompanied by the analysis of satellite images and radar data provided by the airports of Catania-Fontanarossa and Reggio Calabria-Tito Minniti and by a plant on Monte Lauro (SR), as well as the study in-depth analysis of the volcanic tremor and infrasound provided by the INGV monitoring systems.
All this made it possible to reconstruct the issue of a column of ash (so-called plume) of height between 10 and 15 kilometers, the result of an eruption divided into three phases: one first weakly Strombolian phasea whirlpool bath, actual Strombolian phase and finally one lava fountain.
Etna, a continuously changing volcano, has once again made it clear how it can generate various and potentially dangerous volcanological phenomena, which must be constantly monitored.
“Three drone campaigns were necessary, during which 2.311 thermal and non-thermal images were captured, then processed to create the map and quantification of the erupted products, and another field campaign aimed at sampling the current deposit pyroclastic", he adds again De Beni.
“This teamwork has once again highlighted the fundamental importance of the remote volcanological monitoring system of the INGV-OE, but also of the anchor essential direct observation of the 'land geologist' which allowed us to recognize the pyroclastic flow, otherwise not remotely identifiable", concludes the researcher.
Link to the study on Remote Sensing
Useful links:
National Institute of Geophysics and Volcanology (INGV)
Etna Observatory (INGV-OE)
Sapienza University of Rome
University of L'Aquila
University of Cagliari
A volcanic eruption occurred during a snowstorm at the end of May, which generated a pyroclastic flow remained "unnoticed" for about 10 days, until the weather conditions improved and researchers were able to access the summit areas of the volcano.
It might seem like literature but that's what happened last year May 21, 2023 on 'Etna, as described in the study “A Hidden Eruption: The 21 May 2023 Paroxysm of the Etna Volcano (Italy)” created by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV),Sapienza University of Rome,University of L'Aquila and University of Cagliari.
“Our work, in addition to scientifically describing the eruptive event that affected the South-East crater of Etna, wanted to draw attention to the importance and effectiveness of the INGV remote monitoring systems”, explains Emanuela De Beni, volcanologist ofINGV Etna Observatory (INGV-OE) and co-author of the study. “In fact, although the bad weather had obscured the video surveillance cameras installed on the volcano, the other volcanological monitoring stations worked correctly and the signals promptly arrived at our Operations Room in Catania, signaling to us that aneruption with lava fountain and emission of two flows, one towards the South and the other towards the East”.
A week after the eruption, INGV researchers went to the summit area to carry out surveys with drones and proceed with the mapping and quantification of the erupted products.
“Once we arrived on site we realized that a deposit that we had not been aware of until then had actually overlapped the southern flow", goes on De Beni. “After careful soil investigations and sedimentological analyzes we discovered that it was a 'pyroclastic current of density (PDC - Pyroclastic Density Current), i.e. a flow of magmatic material mixed with gas at high temperatures that had descended at high speed from the flanks of the volcano".
At that point, the field and drone surveys were accompanied by the analysis of satellite images and radar data provided by the airports of Catania-Fontanarossa and Reggio Calabria-Tito Minniti and by a plant on Monte Lauro (SR), as well as the study in-depth analysis of the volcanic tremor and infrasound provided by the INGV monitoring systems.
All this made it possible to reconstruct the issue of a column of ash (so-called plume) of height between 10 and 15 kilometers, the result of an eruption divided into three phases: one first weakly Strombolian phasea whirlpool bath, actual Strombolian phase and finally one lava fountain.
Etna, a continuously changing volcano, has once again made it clear how it can generate various and potentially dangerous volcanological phenomena, which must be constantly monitored.
“Three drone campaigns were necessary, during which 2.311 thermal and non-thermal images were captured, then processed to create the map and quantification of the erupted products, and another field campaign aimed at sampling the current deposit pyroclastic", he adds again De Beni.
“This teamwork has once again highlighted the fundamental importance of the remote volcanological monitoring system of the INGV-OE, but also of the anchor essential direct observation of the 'land geologist' which allowed us to recognize the pyroclastic flow, otherwise not remotely identifiable", concludes the researcher.
Link to the study on Remote Sensing
Useful links:
National Institute of Geophysics and Volcanology (INGV)
Etna Observatory (INGV-OE)
Sapienza University of Rome
University of L'Aquila
University of Cagliari
Image: Graphic diagram of the publication.Geographic location of the study area;
The snowstorm obscured the visible and thermal cameras of the INGV-OE monitoring system;
The geophysical signals, such as tremor and infrasound, promptly arrived in the operations room, announcing the lava fountain;
Drone and ground surveys made it possible to identify the existence of a pyroclastic density current and to map and quantify the volcanic products;
The results obtained made it possible to reconstruct the evolution of the hidden event.