Search

Mt. Etna is one of the most closely monitored volcanoes in the world, due to its almost continuous activity and the several hundred thousand people living on its slopes. Its eruptions mainly affect the summit craters, but the great impact on society from its various activities spurred the expansion of both terrestrial and satellite-based ground deformation monitoring networks over the years.We propose a multi-parameter analysis of ground deformation using tilt, high-rate GNSS measurements and DInSAR interferograms recorded during the 2020-2022 lava fountains, to reconstruct the possible shallow feeding system of the volcano that allowed such rapid magma accumulation and discharge. Our analysis showed that the tilt changes are generally similar in magnitude for each episode (between 0.10 and 0.70 microradians) from January to March, while the beginning of the second cycle, from May to June, is characterized by smaller ground deformations, that, only from July, return to typical magnitudes previously measured in the first cycle. Our aim is to identify the differences among the various fountains and between the two cycles by integrating the three different types of ground deformation data for both the first cycle and the second cycle, using tilt data to constrain the sources responsible for each single violent event and the cumulative deformation measured by DInSAR and GNSS solutions to image the deepest part of the source involved in the period., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

In this work, we study a Mediterranean cyclone, that was called Helios and took place during the period 9–11 February 2023 in the southeastern part of Sicily and Malta Island, by a multiparametric approach combining microseism results with sea state and meteorological data provided by wavemeter buoy, HF Radar, hindcast maps and satellite SEVIRI images. The sub-tropical system Helios caused heavy rainfall, strong wind gusts and violent storm surges with significant wave heights greater than 5 meters. We deal with the relationships between such a system and the features of microseism (the most continuous and ubiquitous seismic signal on the Earth) in terms of spectral content, space-time variation of the amplitude and source locations tracked by means of two different methods (amplitude-based grid search and array techniques). By comparing the location of the microseism sources and the area affected by significant storm surges, derived from sea state data, we note that the microseism location results are in agreement with the real position of the storm surges. In addition, we are able to obtain the seismic signature of Helios using a method that exploits the coherence of continuous seismic noise. Hence, we show how an innovative monitoring system of the Mediterranean cyclones can be designed by integrating microseism information with other techniques routinely used to study meteorological phenomena.

Among the geophysical techniques used to monitor volcanic unrest, only gravimetry can supply direct information on changes in the distribution of underground mass over time and can thus provide unique insight into processes such as magma accumulation in void space or gas segregation at shallow depths. Despite its great potential, time-variable volcano gravimetry is not widely adopted, mainly due to the high cost of instrumentation and the difficulty in assessing the relatively small volcano-related gravity changes against unfavorable environmental conditions.Several past studies from Mt. Etna have highlighted the value of gravity observation for improving our understanding of how volcanoes work and characterizing volcanic hazards. In the early stages of application at Mt. Etna, time-lapse and continuous gravity measurements were accomplished using spring gravimeters. Successively, gravimeters based on different technologies have been employed, including superconducting and quantum devices. In most cases, these applications were world firsts at an active volcano.Here, results from different gravimeter types, that have been used to monitor and study Mt. Etna, are presented. Furthermore, the perspectives opened by emerging technologies are highlighted., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Microseism is the most continuous and ubiquitous seismic signal on the Earth and is caused by the interaction between the atmosphere, the hydrosphere and the Solid Earth. In literature, there are several studies that deal with the relationship between microseism and cyclonic activity considering in particular hurricanes, tropical cyclones and typhoons. However, the relationships between microseism and the small-scale tropical cyclones that occur in the Mediterranean Sea, called Medicanes, have never been analysed. For this reason, we considered the Medicane Apollo, which developed in the Ionian Sea and impacted the eastern part of Sicily during the period 25th October to 5th November 2021 causing heavy rainfall (> 400 mm/48h), strong wind gusts (104 km/h) and violent sea waves (significant wave height > 3.5 m). Furthermore, the heavy rainfall induced by the presence of Apollo, caused damage to infrastructure and agriculture forcing the Sicilian regional government to declare a state of emergency for 32 municipalities (in the provinces of Catania, Messina, Siracusa and Ragusa) that were mostly affected by the Medicane Apollo., peer-reviewed

L’obiettivo del lavoro è stato quello di rendere disponibile uno strumento semplice per l’inversione di dati geodetici registrati dalla rete GPS permanente Etnea. Lo strumento sviluppato offre la possibilità di invertire i dati di deformazione sia in tempo quasi reale che offline. Per quanto riguarda l’algoritmo di inversione, è stato utilizzato un approccio probabilistico basato sul metodo denominato Monte Carlo Markov Chain, in grado di stimare la distribuzione della densità a posteriori dei parametri del modello della sorgente vulcanica. Nello strumento sono disponibili sorgenti di tipo sferico e rettangolare per riuscire a modellizzare sia eruzioni sommitali che intrusioni tensili di dicchi. Il risultato finale in uscita al tool riporta su mappa interattiva, la posizione della sorgente stimata e la distribuzione della densità a posteriori di ciascun parametro del modello. Il software è implementato utilizzando strumenti disponibili gratuitamente come Python, JavaScript, PHP.