Studying the fall 2021 eruption with high-speed, high-definition cameras reveals new aspects of explosive volcanism New analysis of the Cumbre Vieja eruption (La Palma, Canary Islands), conducted with qualitative and quantitative observations of the activity of the Tajogaite crater, have provided useful evidence for the physical characterization of the explosive activity of volcanoes, including the Italian ones.
This is what emerges from the study “The Explosive Activity of the 2021 Tajaogaite Eruption (La Palma, Canary Islands, Spain)” conducted by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV),Instituto Tecnológico y de Energías Renovables (ITER) and Canary Volcano Institute (INVOLCAN) of Tenerife (Spain), recently published in the AGU journal 'Geochemistry, Geophysics, Geosystems'.
"The eruption of Tajogaite, which began on 19 September and ended on 13 December 2021, caused extensive damage to the island of La Palma and led to the evacuation of almost 8000 people", explains Piergiorgio Scarlato, INGV volcanologist and co-author of the study. “The explosive activity was characterized by great variability, with the emission of bombs, lapilli and ash in very different ways: this variability provided a rare opportunity to analyze the volcano's behavior in depth and enrich our knowledge knowledge of explosive eruptions".
The explosive activity of the Tajogaite crater, not dissimilar to that of Etna in the early 2000s, due to its persistence and strong variability is not easily attributable within the eruptive 'styles' usually used to describe the activity of volcanoes basaltic.
In two scientific campaigns in the Canary Islands carried out by the research team, the volcano's activity was studied in detail thanks to a large camera deployment comprising a high-speed camera and three high-definition cameras.
"Our instruments have made it possible to obtain unique measurements of the flow of erupted bombs and lapilli, with an average speed of expulsion of the pyroclastic material between 5 and 50 meters per second, with peaks up to over 220 meters per second (about 800 kilometers per second). hour) and flows from a few kilograms up to over 200 tons of material erupted every second, similar to the flow rate of the Tiber river”, explains Jacopo Taddeucci, volcanologist at INGV and co-author of the study.
But what are these marked differences in explosive activity attributable to?
"The variability of explosive activity” continues Scarlato,” it would seem to be controlled by the interaction between various factors, including the flow of magma from the depths, the gas supply, the diameter of the eruptive conduit and the presence of colder and more solidified material inside the conduits. Furthermore, the presence of several eruptive vents active at the same time meant that the magma and the gas were distributed differently from one another, exacerbating the variability of the eruption. On the other hand, similar dynamics have already been observed in other open vent volcanoes, but so far they had been quantified in such detail only for a few eruptions in the Hawaiian Islands and Stromboli".
The use of high-speed cameras has also made it possible to discover that, although apparently continuous and variable, in reality explosive activity is always due to the succession of single 'impulses', very short explosions which are all the more frequent the stronger they are . These pulses offer a new yardstick by which to measure the explosive activity of volcanoes more rigorously than previous qualitative classifications.
"These results are particularly important for us as they underline the need to look at volcanic activity with new eyes, paving the way for a better understanding of the functioning of active basaltic volcanoes in Italy”, concludes Scarlato.
Quote: Taddeucci, J., Scarlato, P., Andronico, D., Ricci, T., Civico, R., Del Bello, E., et al. (2023).
This is what emerges from the study “The Explosive Activity of the 2021 Tajaogaite Eruption (La Palma, Canary Islands, Spain)” conducted by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV),Instituto Tecnológico y de Energías Renovables (ITER) and Canary Volcano Institute (INVOLCAN) of Tenerife (Spain), recently published in the AGU journal 'Geochemistry, Geophysics, Geosystems'.
"The eruption of Tajogaite, which began on 19 September and ended on 13 December 2021, caused extensive damage to the island of La Palma and led to the evacuation of almost 8000 people", explains Piergiorgio Scarlato, INGV volcanologist and co-author of the study. “The explosive activity was characterized by great variability, with the emission of bombs, lapilli and ash in very different ways: this variability provided a rare opportunity to analyze the volcano's behavior in depth and enrich our knowledge knowledge of explosive eruptions".
The explosive activity of the Tajogaite crater, not dissimilar to that of Etna in the early 2000s, due to its persistence and strong variability is not easily attributable within the eruptive 'styles' usually used to describe the activity of volcanoes basaltic.
In two scientific campaigns in the Canary Islands carried out by the research team, the volcano's activity was studied in detail thanks to a large camera deployment comprising a high-speed camera and three high-definition cameras.
"Our instruments have made it possible to obtain unique measurements of the flow of erupted bombs and lapilli, with an average speed of expulsion of the pyroclastic material between 5 and 50 meters per second, with peaks up to over 220 meters per second (about 800 kilometers per second). hour) and flows from a few kilograms up to over 200 tons of material erupted every second, similar to the flow rate of the Tiber river”, explains Jacopo Taddeucci, volcanologist at INGV and co-author of the study.
But what are these marked differences in explosive activity attributable to?
"The variability of explosive activity” continues Scarlato,” it would seem to be controlled by the interaction between various factors, including the flow of magma from the depths, the gas supply, the diameter of the eruptive conduit and the presence of colder and more solidified material inside the conduits. Furthermore, the presence of several eruptive vents active at the same time meant that the magma and the gas were distributed differently from one another, exacerbating the variability of the eruption. On the other hand, similar dynamics have already been observed in other open vent volcanoes, but so far they had been quantified in such detail only for a few eruptions in the Hawaiian Islands and Stromboli".
The use of high-speed cameras has also made it possible to discover that, although apparently continuous and variable, in reality explosive activity is always due to the succession of single 'impulses', very short explosions which are all the more frequent the stronger they are . These pulses offer a new yardstick by which to measure the explosive activity of volcanoes more rigorously than previous qualitative classifications.
"These results are particularly important for us as they underline the need to look at volcanic activity with new eyes, paving the way for a better understanding of the functioning of active basaltic volcanoes in Italy”, concludes Scarlato.
Quote: Taddeucci, J., Scarlato, P., Andronico, D., Ricci, T., Civico, R., Del Bello, E., et al. (2023).
The explosive activity of the 2021 Tajogaite eruption (La Palma, Canary Islands, Spain). Geochemistry, Geophysics, Geosystems, 24, e2023GC010946. https://doi.org/10.1029/2023GC010946
Link to the study: “The Explosive Activity of the 2021 Tajaogaite Eruption (La Palma, Canary Islands, Spain)”
Video link: https://www.youtube.com/shorts/Ydcy25v_bQo
Link to the study: “The Explosive Activity of the 2021 Tajaogaite Eruption (La Palma, Canary Islands, Spain)”
Video link: https://www.youtube.com/shorts/Ydcy25v_bQo
figure 1. INGV researchers at Cumbre Vieja during the explosive activity. In the center, the high-speed camera.
figure 2. Cumbre Vieja eruptive activity 2021 (La Palma, Canary Islands, Spain)
figure 3. INGV researcher at Cumbre Vieja in the first days of the 2021 eruption