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The current unrest phase at Campi Flegrei Caldera, Italy from 2000 to present is evidenced by increasing seismicity rates and magnitude, gas emissions and remarkable ground deformation. We consider multi-technique geodetic data to constrain the recent surface deformations and study the possible hazard implications. Time-series from the COSMO-SkyMed satellite mission and GNSS data in the period 2013-2020 show an increasing rate of uplift at the caldera center, reaching a total of about 1 m in the town of Pozzuoli during 2010-2020. Horizontal deformation confirms the inflationary trend. Also, new GNSS seafloor measurements, located in the Gulf of Pozzuoli and available from 2017 to 2020, show a nearly radial pattern. The use of these data in the analysis, in addition to the inland GNSS and InSAR data, helps constraining the 3D pattern of deformation also in the submerged part of the Campi Flegrei caldera.3D finite element models are developed including the elastic heterogeneous structure of the medium based on the newest seismic tomography of the area of Campi Flegrei. We consider the potential action of a plumbing system composed of a general (without fixing the shape a-priori) “central” source, and a deep tabular layer placed at 7.5 km depth.The results show that the central source is placed below the caldera floor, at 4.5 km depth, and has a shape of a thick spheroid with axes ratio of about 0.8 and 0.5. The use of the sill-like source, as suggested by several previous studies for the 2011-2013 time window, lead to three-four fold higher misfits. We interpret our solution as a thickened sill for which the vertical dimension is not negligible such as for the sill-like source, but has a finite dimension of about half the horizontal extension.No significant contributions from the deep tabular layer are evidenced by the inversions, but the hypothesis of a deep reservoir cannot be fully ruled out, since its activity may be masked by the central shallower source. Also, the implementation of seafloor measurements leads to results compatible with the inland GNSS data alone. In order to understand the evolution of the current inflation process, the results are compared to previous models from the beginning of the present unrest phase (2011 - 2013) and also previous unrest phases (1980-1984).This work is part of the multidisciplinary project LOVE-CF, financed by the Istituto Nazionale di Geofisica e Vulcanologia, to study the dynamics of Campi Flegrei caldera.

Coseismic ground displacement of Turkey/Syria earthquakes of 6th February 2023 from Sentinel-1 SAR data

This work provides the mean ground deformation rates and ground displacement time series of the Campi Flegrei caldera (Italy) retrieved by satellite remote sensing data analysis from 1992 to 2021. Synthetic Aperture Radar (SAR) images acquired by ERS 1–2 (1992–2002), Envisat (2003–2011) and Cosmo-SkyMed (2011–2021) are processed by multi-temporal SAR Interferometry (InSAR) approach using the same technique, parameters and reference system, to obtain for the first time a homogeneous and time-continuous dataset. The validation of the InSAR products is carried out by comparison with the measurements provided by precise levelling lines and cGNSS stations. The produced outcomes offer an overview on the temporal behaviour of ground deformation at Campi Flegrei along an unprecedented time window of about 30 years and can be exploited by the scientific community for supporting and improving the knowledge of the dynamics of the caldera.

In this paper we describe the results of an experimental implementation of the recent guidelines issued by the Italian regulatory body for monitoring hydrocarbon production activities. In particular, we report about the pilot study on seismic, deformation, and pore pressure monitoring of the Mirandola hydrocarbon cultivation facility in Northern Italy. This site hosts the Cavone oil field that was speculated of possibly influencing the 2012 ML 5.8 Mirandola earthquake source. According to the guidelines, the monitoring center should analyse geophysical measurements related to seismicity, crustal deformation and pore pressure in quasi real-time (within 24–48 h). A traffic light system would then be used to regulate underground operations in case of detecting significant earthquakes (i.e., events with size and location included in critical ranges). For these 2-year period of guidelines experimentation, we analysed all different kinds of available data, and we tested the existence of possible relationship between their temporal trends. Despite the short time window and the scarce quantity of data collected, we performed the required analysis and extracted as much meaningful and statistically reliable information from the data. We discuss here the most important observations drawn from the monitoring results, and highlight the lessons learned by describing practical issues and limitations that we have encountered in carrying out the tasks as defined in the guidelines. Our main goal is to contribute to the discussion about how to better monitor the geophysical impact of this kind of anthropogenic activity. We point out the importance of a wider seismic network but, mostly, of borehole sensors to improve microseismic detection capabilities. Moreover, the lack of an assessment of background seismicity in an unperturbed situation -due to long life extraction activities- makes it difficult to get a proper picture of natural background seismic activity, which would be instead an essential reference information for a tectonically-active regions, such as Northern Italy.

The geodetic dataset used in the research article entitled "

We analyse SAR and GPS data to constrain the land subsidence induced by natural and anthropogenic activity along the northern Adriatic coasts (Northern Italy). We develop a procedure in order to cross-validate our results by comparing the retrieved independent InSAR measurements with GPS ground displacements. The results show a good agreement between the different geodetic techniques both in terms of deformation rate and time series. We detected several localized subsidence phenomena with rates of about 2–4 mm/yr along the investigated area likely due to aquifer overexploitation, hydrocarbon extraction activities and natural compaction of the sedimentary basin.

Subsidence can be caused by multiple natural or anthropogenic factors. Natural factors account for compaction of recent sedimentary deposits, oxidation and shrinkage of organic soils. Anthropogenic factors include the pumping of groundwater for human use and the exploitation of hydrocarbon reservoir, both inland and off-shore. The area of Ravenna (Northern Italy) is affected by both anthropogenic and natural subsidence. Natural contribution is due to the compaction of the deposits of the Po plain, of approximately 2 mm/yr. This phenomenon has dramatically increased since the 1950s because of shallow groundwater pumping and deep gas production from several on-shore and off-shore reservoirs in the Upper Adriatic Sea basin.In this work, we used SAR, GPS and levelling data to investigate the deformation detected at Lido Di Dante, located along the coastal area of Ravenna. This area is subject to gas pumping of the Angela-Angelina gas field, a gas reservoir exploited since 1973, with platform located very close to the coast, at approximately 2 km from the shoreline. We analysed SAR data from multiple missions from 1992 to 2018. In particular, the ESA’s archives were exploited considering ERS data (ascending and descending orbits, spanning 1992-2000), ENVISAT data (ascending and descending orbits, 2003-2010) and Sentinel-1 satellites (ascending and descending orbits, 2015-2018) and ASI’s images acquired by Cosmo-SkyMed (ascending orbit, 2011-2017). The GPS data are provided by Eni S.p.A. In particular, we consider the GPS ANGA, located offshore on the Angela-Angelina platform, and the GPS FIUN, located near Lido Di Dante. The levelling data are from Eni S.p.A. archives, span 1983-2017.The subsidence detected by InSAR (Interferometric SAR) time series at Lido Di Dante from 1992 to 2018 is approximately 250 mm. The ERS time series show a change in the slope between 1997 and 1998, when the Angela-Angelina platform came into operation. There is a general correlation between gas extraction and surface deformation, indeed the subsidence increases when the gas production increases. Therefore, to better analyze the correlation between gas extraction and observed deformation, the exploited reservoir is modelled as a closing crack (dislocation tensile fault), whose contraction rate is constrained by data inversions. The results indicate that the subsidence in the area of Lido di Dante is the sum of natural contribution due to soil compaction and of hydrocarbon extraction activities during the periods of massive extraction.In order to better discriminate the factors affecting subsidence we build a Finite Element Model, by means of the software Comsol Multiphysics. The geometry of reservoir has been deduced by literature, while the pressure inside the reservoir is modulated by the GPS signals at ANGA between 1998 and 2018. The results show that the contraction of reservoir due to gas pumping produces measurable deformation along the coastline. The vertical and horizontal cumulative displacements between 1998 and 2018 reach the maximum values of 28 cm and 15-20 cm, respectively.

In this work we exploit X- and C-band InSAR data for detecting local deformation phenomena induced by the 2016–2017 Central Italy seismic sequence. Our goal is to highlight the usefulness of multi-band InSAR analysis for Hazard assessing and Rapid Mapping purposes when in-situ investigations are difficult or dangerous to be performed. Indeed, local seismic-induced effects (such as landslides, avalanches, subsidence, etc.) could severely impact the environment and the population in the surrounding of areas hit by earthquakes. We focused on four areas, named Monte Vettore, Podalla, Bolognola and Cicconi, where InSAR outcomes revealed how the main seismic events of the sequence activated several landslides and secondary faults interested by deformation of ~ 2–3 cm along the satellite Line-of-Sight (LoS). The use of multi-band InSAR data allows the observation of multi-scale deformation phenomena with both different spatial resolution and coverage, highlighting the limits and constraints of different SAR sensors. Moreover, it ensures the crosschecking of displacement patterns retrieved through different InSAR products, especially when no ground truth or in situ ancillary data are available for validation purposes. As a result, the retrieved InSAR information can support the Scientific Community and the Institutions in the management of crisis emergencies.

We investigate a large geodetic data set of interferometric synthetic aperture radar (InSAR) and GPS measurements to determine the source parameters for the three main shocks of the 2016 Central Italy earthquake sequence on 24 August and 26 and 30 October (Mw 6.1, 5.9, and 6.5, respectively). Our preferred model is consistent with the activation of four main coseismic asperities belonging to the SW dipping normal fault system associated with the Mount Gorzano-Mount Vettore-Mount Bove alignment. Additional slip, equivalent to a Mw ~ 6.1–6.2 earthquake, on a secondary (1) NE dipping antithetic fault and/or (2) on a WNW dipping low-angle fault in the hanging wall of the main system is required to better reproduce the complex deformation pattern associated with the greatest seismic event (the Mw 6.5 earthquake). The recognition of ancillary faults involved in the sequence suggests a complex interaction in the activated crustal volume between the main normal faults and the secondary structures and a partitioning of strain release.

We use both Synthetic Aperture Radar (SAR) and Optical data to constrain the co-seismic ground deformation produced by the 2018 Mw 7.5 Sulawesi earthquake. We exploit data processing techniques mainly based on pixel cross-correlation approach, applied to Synthetic Aperture Radar (SAR) and optical images to estimate the North–South (NS) displacement component. This component is the most significant because of the NNW–SSE geometry of the fault responsible for the seismic event, i.e., the Palu-Koro fault, characterized by a strike-slip faulting mechanism. Our results show a good agreement between the different data allowing to clearly identify the surface rupture due to the fault slip. Moreover, we use SAR and optical intensity images to investigate several secondary phenomena generated by the seismic event such as tsunami, landslides, and coastal retreat. Finally, we discuss differences between SAR and optical outcomes showing strengths and disadvantages of each one according to the investigated phenomenon.

The use of SAR data for imaging hazardous events is nowadays a well-consolidated approach. Thanks to the synoptic capabilities of satellite data, their high spatial resolution and high revisit time, fast and accurate analysis can be performed at both regional and local scale. This work presents the results of SAR Interferometry applied to a multi-hazard event induced by the eruption of Etna volcano, occurred in late December 2018. We analyse both the syn-eruptive deformation of volcano edifice and the effects of an induced M w 4.9 earthquake and a small-scale landslide by exploiting ESA Sentinel-1 data. The data highlight a main horizontal displacement of the Etna summit of more than 40 cm and 65 cm along west and east directions, respectively. The earthquake caused about 15 cm displacement toward east and 20 cm toward west. Finally, approximately 5 cm displacement along satellite Line of Sight was observed associated to the landslide.

Campi Flegrei caldera (Italy) was affected by a new unrest phase during 2011–2013. We exploit two COSMO-SkyMed data sets to map the deformation field, obtaining displacement rates reaching 9 cm/yr in 2012 in the caldera center. The resulting data set is fitted in a geophysical inversion framework using finite element forward models to account for the 3-D heterogeneous medium. The best fit model is a north dipping mixed-mode dislocation source lying at ~5 km depth. The driving mechanism is ascribable to magma input into the source of the large 1982–1984 unrest (since similar source characteristics were inferred) that generates initial inflation followed by additional shear slip accompanying the extension of crack tips. The history and the current state of the system indicate that Campi Flegrei is able to erupt again, and the advanced techniques adopted provide useful information for short-term forecasting.

Como historic centre, located at the SW branch of Lake Como (northern Italy), is prone to subside because of a thick sequence of late Pleistocene to Holocene glacio-lacustrine, palustrine and alluvial sediments in the subsoil. After the 1950s, the combination of natural causes and anthropogenic activities amplified subsidence-induced differential settlements at building foundation depths, resulting in damage on the superstructures. This work presents the first subsidence vulnerability analysis of the historic buildings in Como city centre by combining hydrogeological and stratigraphic features, in situ damage investigations, and remote sensing Synthetic Aperture Radar (SAR) data acquired by Cosmo-SkyMed mission. First, the relationships between local hydrogeological features and vertical displacements retrieved by SAR Interferometry (InSAR) analysis were qualitatively assessed. This highlighted that cumulative vertical InSAR-derived settlements have a stronger linear correlation with the groundwater level rather than the thickness of compressible soil units at the city scale. The largest vertical displacements are located in the NW sector of the city centre and along the shore of Lake Como, where they remark the pre-Roman shoreline. Then, the cause-effect relationships between building damage severity and Subsidence-Related Intensity (SRI) parameters were investigated using a probabilistic approach based on empirical fragility curves. To this aim, two InSAR-derived SRI parameters were tested for both masonry and reinforced concrete buildings: differential settlements and relative rotations. The former resulted to relate better to distinct damage levels in Como historic centre. The analyses performed can contribute to the management of the inestimable architectural and cultural heritage of Como historic centre.

We present new 40Ar/39Ar data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36 kyr) overruns the recurrence time (31 kyr) in the last 100 kyr. New interferometric synthetic aperture radar data, covering the years 1993–2010, reveal ongoing inflation with maximum uplift rates (>2 mm/yr) in the area hosting the most recent (

This study focuses on testing the SAR coherence changes from Sentinel-1 data to detect burned areas and to compare the results with optical Sentinel-2 derived burned area product to be used as validation. Visible Infrared Imaging Radiometer Suite (VIIRS) data at 350 m resolution was used to identify active fires locations. We focused on a sequence of wildfires that affected the Sila mountain area during the summer of the 2017. This area of the Calabria region (southern Italy) was interested by a range of fires for the second half of July and the whole month of August ([1], [2]) due also to an extremely dry and hot summer. We used a pair of optical images acquired from Sentinel- 2 satellites on 24 July 2017 (pre-events) and 23 August 2017 (post-events). Firstly, we computed the Normalized Difference Vegetation Index (NDVI) for both images and calculated the difference between these two (dNDVI) at 10m resolution; the results put in evidence several areas characterized by vegetation reduction, with dNDVI values up to 0.3-0.4. Concerning the SAR data, we evaluated the coherence changes by exploiting two pairs of Sentinel-1 SAR data over the same area. Both pairs were acquired along descending orbit, respectively before (on July, 19th and 31st) and after (on September, 5th and 17th) the fires occurred in the Sila mountain area. The coherence was computed separately for the first (γpre) and the second pair (γpost) and the difference γpost - γpre was calculated. In this way, we evaluated the difference in coherence between September, i.e. post-fires, and July, i.e. pre-fires expecting a higher coherence after burning, due to the vegetation reduction. In several areas, the coherence seems to be consistent with the fire events showing increments up to 0.20-0.25. However, the increasing of coherence difference could also be due to other reasons such as the soil moisture variations in the proximity of lakes/rivers or the seasonal cultivation changes. Further analysis integrating more information such as the SAR amplitude signal and the cross-polarized backscattering coefficient will be conducted in order to better evaluate and discriminate any contributions.

In this study, multi-frequency Synthetic Aperture Radar Interferometry (InSAR) data are used to constrain the ground deformation due to the August 21st, 2017, Ischia earthquake. InSAR results are the input data to infer the source model of the seismic event. C-band Sentinel-l and X-band COSMO-SkyMed© InSAR results show a displacement pattern in the epicentral area, with a maximum value of ~3.5 cm and a dominant vertical component. Preliminary analytical and numerical models suggest that the retrieved InSAR ground displacements are due to the combination of two phenomena: the tectonic dislocation caused by the slip on the fault plane and the surficial disnlacernent caused by the triggering of shallow landslides.

We exploit C-band Sentinel-1 and L-band ALOS-2 Synthetic Aperture Radar Interferometry (InSAR) data to constrain the seismic source of the $\mathrm{M}_{\mathrm{w}}$ 6.0 intraplate earthquake occurred on May 20, 2016 in the central Australia. It is an uncommon seismic event since it occurred in a region characterized by low seismic activity. The retrieved source modeling revealed that the earthquake nucleated along a NW-SE-oriented reverse fault with a significant strike-slip component.

We measured ground displacements before and after the 2009 L’Aquila earthquake using multi-temporal InSAR techniques to identify seismic precursor signals. We estimated the ground deformation and its temporal evolution by exploiting a large dataset of SAR imagery that spans seventy-two months before and sixteen months after the mainshock. These satellite data show that up to 15 mm of subsidence occurred beginning three years before the mainshock. This deformation occurred within two Quaternary basins that are located close to the epicentral area and are filled with sediments hosting multi-layer aquifers. After the earthquake, the same basins experienced up to 12 mm of uplift over approximately nine months. Before the earthquake, the rocks at depth dilated, and fractures opened. Consequently, fluids migrated into the dilated volume, thereby lowering the groundwater table in the carbonate hydrostructures and in the hydrologically connected multi-layer aquifers within the basins. This process caused the elastic consolidation of the fine-grained sediments within the basins, resulting in the detected subsidence. After the earthquake, the fractures closed, and the deep fluids were squeezed out. The pre-seismic ground displacements were then recovered because the groundwater table rose and natural recharge of the shallow multi-layer aquifers occurred, which caused the observed uplift.

We use X-band Cosmo-SkyMed InSAR data to highlight several subsidence phenomena resting on some railway and road infrastructures in Lombardia region, Northern Italy, mainly induced by anthropogenic activities. We show eight case studies, namely “Como,” Erba, Oggiono, Valmadrera, Olginate, Verduggio, Melzo, and San Giuliano M., where we detect local subsidence effects affecting several railway and highway lines with deformation rates of about 5 mm/year. The geological features of this part of Italy and the large presence of industrial areas in the surrounding of Milano, Lecco, and Como cities lead to such phenomena. The stability and security of the nested road and railway network could be affected by these surface deformation fields. To guarantee the safety of people, continuous maintenance of the condition of railways and roads together with the monitoring of the conditions of the lands on which they rest on should be done.

In this work, we propose an improved algorithm to constrain the 3D ground displacement field induced by fast surface deformations due to earthquakes or landslides. Based on the integration of different data, we estimate the three displacement components by solving a function minimization problem from the Bayes theory. We exploit the outcomes from SAR Interferometry (InSAR), Global Positioning System (GNSS) and Multiple Aperture Interferometry (MAI) to retrieve the 3D surface displacement field. Any other source of information can be added to the processing chain in a simple way, being the algorithm computationally efficient. Furthermore, we use the intensity Pixel Offset Tracking (POT) to locate the discontinuity produced on the surface by a sudden deformation phenomenon and then improve the GNSS data interpolation. This approach allows to be independent from other information such as in-situ investigations, tectonic studies or knowledge of the data covariance matrix. We applied such a method to investigate the ground deformation field related to the 2014 Mw 6.0 Napa Valley earthquake, occurred few kilometers from the San Andreas fault system., This work has been supported by the project FIRB RBAP10ZC8K_002. Research by JF has been supported by the Spanish Ministry of Economy and Competitiveness research project ESP2013-47780-557 C2-1-R and the EU 7th FP MED-SUV project (contract 308665). It is a contribution to the Moncloa Campus of International Excellence.

On 21 May 2016, an Mwp 6.1 earthquake occurred along the Petermann Ranges in Central Australia. Such a seismic event can be classified as a rare intraplate earthquake because the affected area presents low seismicity, being at the center of the Indo-Australian plate. Also, the architecture and kinematics of shear zones in the Petermann Orogen are largely unknown. We used Sentinel-1 C-band descending data and ALOS-2 L-band ascending data to constrain the causative fault. Our analysis revealed that the earthquake nucleated along an unmapped secondary back-thrust of the main feature of the area, namely the Woodroffe thrust.