Search

The deformation style of active volcanoes can provide insight into the structural evolution of their edifices, volcanic activity and associated hazards. The Somma‐Vesuvius volcano is considered one of the most dangerous on the planet due to its proximity to the megacity of Naples (Southern Italy). Thus, understanding its deformation style and corresponding long‐term structural evolution are critical aspects for risk reduction. Although a large amount of data has already been collected about Somma‐Vesuvius, the deformation style affecting its volcanic edifice is still debated. Therefore, we devised an integrated approach to clarify the current state of deformation of this volcano. In particular, we combined analog experiments and finite element (FE) modeling to constrain the current deformation style affecting Somma‐Vesuvius and determine the physical parameters controlling its structural evolution. The analog models were built at a scale of 1:100,000 using sand mixtures (brittle analog) and polydimethylsiloxane (ductile analog). The FE models were implemented by considering a three‐dimensional time‐dependent fluid‐dynamic approach performed at both the analog model scale (1:100,000) and actual volcano scale (1:1). We obtained an FE model and a corresponding analog one that faithfully reproduced the observed deformation velocity patterns revealed by differential interferometric synthetic aperture radar (DInSAR) and GPS measurements at Somma‐Vesuvius. Overall, our results support the hypothesis that a combined gravitational spreading‐sagging process governs the deformation style of Somma‐Vesuvius. Plain Language Summary: Volcanic edifices of sufficient mass are capable of deforming substrata under their own weight; this deformation in turn can deform the volcanic edifices themselves. Identifying the deformation style characterizing a volcanic edifice is useful when considering the evolution of its volcanic activity. Vesuvius is considered one of the most dangerous volcanoes on the planet due to its proximity to the megacity of Naples (Southern Italy). Thus, understanding its deformation style and corresponding structural evolution are critical aspects for risk reduction. In order to analyze the deformation process of Vesuvius we used two different modeling techniques: analog modeling and Finite Element numerical modeling. The analog modeling approach allows us to reproduce real processes by using scaled models and media considered analog to natural materials under a physical point of view. The combination of analog and numerical modeling allowed us to constrain the current deformation style affecting Somma‐Vesuvius and to determine the physical parameters controlling its structural evolution. Finally, we compared our results with the observed deformation velocity patterns revealed by Differential Interferometric Synthetic Aperture Radar and GPS measurements at Vesuvius. Overall, the results support the hypothesis that a combined gravitational spreading‐sagging process governs the deformation style of Somma‐Vesuvius. Key Points: Analog and numerical modeling highlighted an active spreading‐sagging process at the Somma‐Vesuvius volcanoA comparison of models with differential interferometric synthetic aperture radar (DInSAR) deformation data validated the modeling proceduresThe spreading process affecting the Vesuvius volcano allowed inferring about the near‐future eruption style [ABSTRACT FROM AUTHOR]

Uturuncu volcano (southwestern Bolivia) is localized within one of the largest updoming volcanic zones, the Altiplano Puna Volcanic Complex (APVC). In several geodetic studies the observed uplift phenomenon is analyzed and modeled by considering a deep source, related to the Altiplano Puna Magma Body (APMB). In this framework, we perform a multiscale analysis on the 2003–2010 ENVISAT satellite data to investigate the existence of a multi-source scenario for this region. The proposed analysis is based on Cross-correlation and Multiridge method, pointing out the spatial and temporal multiscale properties of the deformation field. In particular, we analyze the vertical component of ground deformation during two time interval: within the 2005–2008 time interval an inflating source at 18.7 km depth beneath the central zone of the APVC is retrieved; this result is in good agreement with those proposed by several authors for the APMB. Between August 2006 and February 2007, we identify a further inflating source at 4.5 km depth, beneath Uturuncu volcano; the existence of this latter, located just below the 2009–2010 seismic swarm, is supported by petrological, geochemical, and geophysical evidence, indicating as a possible interpretative scenario the action of shallow, temporarily trapped fluids. [ABSTRACT FROM AUTHOR]

Monitoring crustal deformation in active volcanic areas could not be an easy task. In this sense, remote sensing can make the difference with respect to in-situ techniques, due to its capability to provide dense measurements at large spatial scale and at relatively low cost. In particular, the Differential Synthetic Aperture Radar Interferometry (DInSAR) is becoming one of the usual techniques to measure ground deformation in any atmospheric conditions and with a high accuracy level.The increasing diffusion of the use of DInSAR is also due to the recent large availability of huge and easily accessible SAR data archives. Indeed, since late 2014, the Copernicus Sentinel-1 constellation is globally providing SAR data with a repeat-pass frequency that, in the best cases, is of 6 days. Just to understand the impact of such Earth Observation program, it is worth noting that nowadays the Sentinel-1 system acquires about 12 TB of SAR data per day all over the Earth.It is therefore clear that with such a huge, global, constant and reliable availability of data it is possible to use the DInSAR technique for monitoring purposes, such as those related to the measurements of the ground motion in volcanic areas.In this work we present the implementation of an operative service for monitoring the crustal deformation in active volcanoes through the use of DInSAR technique and Sentinel-1 data. The designed system is fully automatic and the process is triggered by the availability, for every monitored volcano site, of a new SAR data in the Sentinel-1 catalogues acquired from both ascending and descending passes. The data, per each orbit, are then ingested and processed through the well-known Parallel Small BAseline Subset (P-SBAS) DInSAR technique in order to generate the displacement time series. The so-retrieved Line of Sight (LOS) measurements are then combined to compute the Vertical and East-West component of the deformation, which are directly understandable by the end user.The system is currently operative for the main active Italian volcanoes, such as the Campi Flegrei caldera, Mt. Vesuvius, Ischia, Mt. Etna and Stromboli, but it can be easily extended to include other volcanic areas on Earth. Indeed, although the service is intended to serve the Italian Department of Civil Protection, it is based on widely used IT standards so that it can be easily ported to several computing environments, such as those made available by the Copernicus DIAS. Moreover, it is planned to make available the generated DInSAR results to the Solid Earth community through the EPOS Research Infrastructure. Retrieved deformation results and their implication in the volcano behavior understanding will be discussed at the conference.This work is supported by: the 2019-2021 IREA-CNR and Italian Civil Protection Department agreement; the H2020 EPOS-IP project (GA 676564); the I-AMICA (PONa3_00363) project; and the IREA-CNR/DGS-UNMIG agreement. [ABSTRACT FROM AUTHOR]

In this study, we combine two interferometric techniques Synthetic Aperture Radar (SAR) and Ambient Noise Tomography (ANT) to investigate the 2011-13 unrest phenomenon at Campi Flegrei Caldera (Southern Italy). In particular, the SAR Interferometry (InSAR) images both the spatial and the temporal features of the occurred ground deformation, while the ANT provides independent structural seismic constraints necessary to interpret deformation dynamics. For the first time we apply the Total Horizontal Derivative (THD) analysis to the ground deformation field detected via SAR Interferometry and COSMO-SkyMed data to better identify the complexity of the caldera structure. We superimpose the THD maps and the epicenters of the earthquakes, recorded between January 2011 and December 2013, on the ANT images obtained using seismic interferometry, with the aim of linking these different, independent, observations. The comparison of the THD and ANT results shows that the caldera rim and the residuals of previous eruptions limit the horizontal propagation of the magmatic intrusion within the sill-like structures. The best correlation between the THD and ANT images is achieved at a seismic period of 1.2 s, corresponding to ~1 km; however, the spatial correlation is persistent at least down to ~ 1.7 km (2 s). The maxima values of the THD results describe a spatial pattern coinciding with the high-velocity structure between Solfatara and Pisciarelli, the area where most of the background seismicity is located during the 2011-2013 period.The proposed combined application of SAR and seismic interferometry techniques represents a good option to quantitatively model in space and time the characteristics and nature of the deformation source; indeed, it can provide a new perspective to understand the origin of real-time deformation signal at volcanoes where magma propagation within sills is expected, as for the Campi Flegrei Caldera case. [ABSTRACT FROM AUTHOR]

Mount Etna is a large basaltic stratovolcano located on the eastern coast of Sicily (Southern Italy) and it is one of the best-known and most intensely monitored volcanoes of the planet, implying significant recent progress in the knowledge of its dynamics. Among others, the availability of space-borne SAR data provides accurate information on the volcano morphology and deformation, particularly during emergency phases, when it is difficult or even impossible to carry out in-situ surveys. Therefore, a fast availability and processing of the SAR data is crucial to help understanding the on-going volcano dynamic.Since 24 December 2018, a new intense Etna activity has started and it has been associated with a relevant seismic sequence that culminated with a Mw 4.9 earthquake, occurred on 26 December 2018 on the lower part of the Eastern volcano flank. In this work, we investigate both the volcanic eruption process and the Mw 4.9 mainshock nucleation by using DInSAR measurements, seismological data and analytic modelling. In particular, we exploit the DInSAR measurements obtained from coseismic SAR data pairs collected by the Sentinel-1 and COSMO-SkyMed satellites from ascending and descending orbits. All of these data have been processed immediately after their availability and have been shared with the National Authorities to manage the volcano crisis. By benefiting from the availability of different orbits (ascending and descending), we retrieve the Vertical and East-West components of the displacements affecting the analyzed area. The obtained results show that the East-West component presents the most significant displacement entities, whose maximum values exceed about 30 cm towards West and about 50 cm towards East close to the volcano summit. In addition, in the area in correspondence to the 26 December main shock, maximum eastward and westward displacements of 12-14 cm and 15-17 cm are observed, respectively.Moreover, we analyse the distribution of the relocated hypocentres in order to identify the involved and activated structures and, to better constrain the geometry and characteristics of the main sources, we extend our analysis by applying a modelling approach based on the analytical method. In particular, we invert DInSAR measurements to get the combination of seismic and vulcanic sources that better predict the displacement field; non-linear and linear modeling inversions are performed to retrieve source geometries, tensile and shear component distributions. [ABSTRACT FROM AUTHOR]