Etna 2004–2005: An archetype for geodynamically-controlled effusive eruptions

The 2004–05 eruption of Etna was characterised by outpouring of degassed lava from two vents within Valle del Bove. After three months of eruption lava volumes were estimated to be between 18.5 and 32 × 106 m3, with eruption rate between 2.3 and 4.1 m3/s. Petrological analyses show that magma is resident in the shallow plumbing system, emplaced during the last South-East Crater activity. SO2 flux data show no increase at the onset of the eruption and SO2/HCl ratios in gas emitted from the eruptive fissure are consistent with a degassed magma. No seismic activity was recorded prior to eruption, unlike eruptions observed since the 1980's. The purely effusive nature of this eruption, fed by a degassed, resident magma and the fracture dynamics suggest that magmatic overpressure played a limited role in this eruption. Rather, lateral spreading of Etna's eastern flank combined with general inflation of the edifice triggered a geodynamically-controlled eruption.Published1-4partially_ope

Major eruptive style changes induced by structural modifications of a shallow conduit system: the 2007–2012 Stromboli case

Stromboli is known for its mild, persistent explosive activity from the vents located within the summit crater depression at the uppermost part of the Sciara del Fuoco (SdF) depression. Effusive activity (lava flows) at this volcano normally occurs every 5–15 years, involving often the opening of eruptive fissures along the SdF, and more rarely overflows from the summit crater. Between the end of the 2007 effusive eruption and December 2012, the number of lava flows inside and outside the crater depression has increased significantly, reaching a total of 28, with an average of 4.8 episodes per year. An open question is why this activity has become so frequent during the last 6 years and was quite rare before. In this paper, we describe this exceptional activity and propose an interpretation based on the structural state of the volcano, changed after the 2002–2003 and even more after the 2007 flank effusive eruption. We use images from the Stromboli fixed cameras network, as well as ground photos, plume SO2 and CO2 fluxes released by the summit crater, and continuous fumarole temperature recording, to unravel the interplay between magma supply, structural and morphology changes, and lava flow output. Our results might help forecast the future behaviour and hazard at Stromboli and might be applicable to other openconduit volcanoes.partially supported by the Project INGV-DPC Paroxysm V2/03, 2007–2009 funded by the Istituto Nazionale di Geofisica e Vulcanologia and the Italian Civil ProtectionPublished8413V. Dinamiche e scenari eruttiviJCR Journalrestricte

Combining thermal imaging with photogrammetry of an active volcano using UAV : an example from Stromboli, Italy

The authors would like to thank the Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Catania (INGV‐CT) for granting permission to conduct the UAV surveys over the Stromboli volcano. This work was supported by the School for Early Career Researchers at the University of Aberdeen, UK. Dougal Jerram is partly funded through a Norwegian Research Council Centres of Excellence project (project number 223272, CEED). The team would like to thank Angelo Cristaudo for logistical help during the fieldwork efforts on Stromboli.Peer reviewedPostprin

Changes in the eruptive style of Stromboli Volcano before the 2019 paroxysmal phase discovered through SOM clustering of seismo-acoustic features compared with camera images and GBInSAR data

Two paroxysmal explosions occurred at Stromboli on 3 July and 28 August 2019, the first of which caused the death of a young tourist. After the first paroxysm an effusive activity began from the summit vents and affected the NW flank of the island for the entire period between the two paroxysms. We carried out an unsupervised analysis of seismic and infrasonic data of Strombolian explosions over 10 months (15 November 2018–15 September 2019) using a Self-Organizing Map (SOM) neural network to recognize changes in the eruptive patterns of Stromboli that preceded the paroxysms. We used a dataset of 14,289 events. The SOM analysis identified three main clusters that showed different occurrences with time indicating a clear change in Stromboli’s eruptive style before the paroxysm of 3 July 2019. We compared the main clusters with the recordings of the fixed monitoring cameras and with the Ground-Based Interferometric Synthetic Aperture Radar measurements, and found that the clusters are associated with different types of Strombolian explosions and different deformation patterns of the summit area. Our findings provide new insights into Strombolian eruptive mechanisms and new perspectives to improve the monitoring of Stromboli and other open conduit volcanoes