| Title: |
Volcanic gas changes prior to Stromboli's major explosions are statistically significant |
| Authors: |
Aiuppa A.; Bitetto M.; Curcio L.; Delle Donne D.; Lages J.; Lo Bue Trisciuzzi G.; Tamburello G.; Vitale A.; Cannavo F.; Coltelli M.; Coppola D.; Innocenti L.; Insinga L.; Lacanna G.; Laiolo M.; Massimetti F.; Pistolesi M.; Privitera E.; Ripepe M.; Voloschina M.; Cilluffo G. |
| Contributors: |
Aiuppa, A.; Bitetto, M.; Curcio, L.; Delle Donne, D.; Lages, J.; Lo Bue Trisciuzzi, G.; Tamburello, G.; Vitale, A.; Cannavo, F.; Coltelli, M.; Coppola, D.; Innocenti, L.; Insinga, L.; Lacanna, G.; Laiolo, M.; Massimetti, F.; Pistolesi, M.; Privitera, E.; Ripepe, M.; Voloschina, M.; Cilluffo, G. |
| Publication Year: |
2025 |
| Collection: |
ARPI - Archivio della Ricerca dell'Università di Pisa |
| Subject Terms: |
CO2; Eruption forecasting; Major explosion; SO2; Statistical analysi; Stromboli; Volcanic gases |
| Description: |
The generally mild activity of mafic, open-vent volcanoes is punctuated by the periodic occurrence of sudden, larger-than-normal explosive eruptions. Examples of these sudden mafic explosive events are the so-called “major explosions” that occur (2 to 4 times a year on average) at Stromboli volcano in Italy. These relatively small explosions (Volcanic Explosivity Index, VEI < 1) occur without no obvious precursory change in surface activity, and therefore pose a threat to volcanologists/monitoring staff, and to the population in the most severe cases. Past work has found a link between periods of high CO2/SO2 ratios in the volcanic gas plume and the occurrence of such explosions, but this association has never been statistically verified. Here, we report on nearly continuous observations of volcanic gas plume CO2 and SO2 concentrations and ratios in a diluted plume, as well as SO2 flux measurements, recorded in a four year (2020 to 2023) activity period of Stromboli volcano, during which 22 such major explosions took place. Using the Conditional Logit model and the Receiver Operating Characteristic (ROC) analysis, we establish a statistical association between the occurrence of major explosions and periods of reduced SO2 concentrations (very significant) and fluxes, and high CO2/SO2 ratios (significant), in the volcanic plume. These findings are interpreted in light of a simplified conceptual model that explains major explosions as caused by gas bubble accumulation at a rheological discontinuity, resulting from deceleration of the shallow convecting magma that supplies the “regular” Strombolian activity. Using results of statistical analysis, we develop a volcanic gas-based Composite indicator that successfully forecasts (by a-posteriori analysis) 71 % of the events on timescales of week(s). However, we find that this Composite indicator is associated with a large (32 %) False Positive rate and hence low precision (20 %). The significant role of SO2 concentrations in the model indicates that other factors, ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
ELETTRONICO |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/wos/WOS:001461472600001; volume:462; numberofpages:16; journal:JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH; https://hdl.handle.net/11568/1336975 |
| DOI: |
10.1016/j.jvolgeores.2025.108325 |
| Availability: |
https://hdl.handle.net/11568/1336975; https://doi.org/10.1016/j.jvolgeores.2025.108325 |
| Rights: |
info:eu-repo/semantics/openAccess ; license:Creative commons ; license uri:http://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.EBF338ED |
| Database: |
BASE |