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This work is aimed at showing that an effective integration of advanced remote sensing methods and new ICT technologies allows the full exploitation of large volumes of Earth Observation (EO) data, contributing to deeply investigate the Earth System processes and to address new challenges within the Big Data scenario. In particular, we present an automatic pipeline implemented within the Amazon Web Services (AWS) Cloud Computing platform for the interferometric processing of large Sentinel- 1 (S1) multi-temporal SAR datasets, aimed at analyzing Earth surface deformation phenomena at wide spatial scale. The developed processing chain is based on the advanced DInSAR approach referred to as Small BAseline Subset (SBAS) technique, which allows producing, with centimeter to millimeter accuracy, surface deformation time series and the corresponding mean velocity maps from a temporal sequence of SAR images. The implemented solution addresses the aspects relevant to i) S1 input data archiving; ii) interferometric processing of S1 data sequences, performed in parallel on the AWS computing nodes through both multi-node and multi-core programming techniques; iii) storage of the generated interferometric products. The experimental results are focused on a national scale DInSAR analysis performed over the whole Italian territory by processing 18 S1 slices acquired from descending orbits between March 2015 and April 2017, corresponding to 2612 S1 acquisitions.

In Switzerland, more than 60% of the territory is mountainous, and this characteristic is a main natural resource attracting every year millions of tourists. However, this peculiarity exposes the country also to hazard potential due to the effect of different slope processes (e.g. deep seated gravitational deformations, rock avalanches, rock falls, debris flows, etc.). Moreover, the value of infrastructures and the strategic importance of transportation corridors present in Switzerland expose also neighboring countries to direct and indirect risks in case of catastrophic events. In this scenario, studying surface deformation may help understanding mountain processes, detecting preparatory conditions for potential failure events, and eventually planning countermeasures. Among EO methods, spaceborne radar interferometry has demonstrated great advantages to perform this task. Moreover, the recent advent of the Copernicus Sentinel-1 (S1) constellation has increased our capability to observe surface deformation over wide regions with higher revisit times. Here we present the results obtained by processing 107 images acquired from S1 constellation between April 20, 2015 and March 11, 2018. Differential interferograms were computed and combined taking advantage of the P-SBAS algorithm to obtain ground velocities and displacement time series at the country scale. We discuss the potential of such datasets in alpine countries such as Switzerland, as well the challenges for their thoughtful utilization.

In this work we implement a completely automatic interferometric processing chain, based on the well-known advanced DInSAR algorithm referred to as Parallel Small BAseline Subset (P-SBAS), for the generation of Sentinel-1 (S-1) Interferometric Wide Swath (IWS) deformation mean velocity maps and time-series of very wide areas, implemented within the Amazon Web Services (AWS) Elastic Cloud Compute environment. Our processing chain consists of the initial data query to the S-1 archive that we created on the AWS S3 storage, then the data transfer to the AWS computing nodes, the data processing and, finally, the transfer of the obtained interferometric results back to the original S3 storage.

We are writing this comment because many aspects of the analysis presented by Nappi et al. (2018) are debatable. In particular, a major issue is relevant to the conclusion suggested by Nappi et al. (2018) about a seismogenic normal fault with northward dip; this finding is not grounded because the Authors do not really present a causative source model and, above all, their statement is clearly not consistent with the DInSAR, GPS and seismological measurements presented in the manuscript previously published by De Novellis et al. (2018). Moreover, we also report an evident error in the geologic map proposed by Nappi et al. (2018), see Figure 3 of their manuscript.

Trabajo presentado en la European Geosciences Union General Assembly, celebrada en Viena (Austria), del 23 al 28 de abril de 2017, EPOS, the European Plate Observing System, is a long-term plan to facilitate the integrated use of data, data products, software and services, available from distributed Research Infrastructures (RI), for solid Earth science in Europe. Indeed, EPOS integrates a large number of existing European RIs belonging to several fields of the Earth science, from seismology to geodesy, near fault and volcanic observatories as well as anthropogenic hazards. The EPOS vision is that the integration of the existing national and trans-national research infrastructures will increase access and use of the multidisciplinary data recorded by the solid Earth monitoring networks, acquired in laboratory experiments and/or produced by computational simulations. The establishment of EPOS will foster the interoperability of products and services in the Earth science field to a worldwide community of users. Accordingly, the EPOS aim is to integrate the diverse and advanced European Research Infrastructures for solid Earth science, and build on new e-science opportunities to monitor and understand the dynamic and complex solid-Earth System. One of the EPOS Thematic Core Services (TCS), referred to as Satellite Data, aims at developing, implementing and deploying advanced satellite data products and services, mainly based on Copernicus data (namely Sentinel acquisitions), for the Earth science community. This work intends to present the technological enhancements, fostered by EPOS, to deploy effective satellite services in a harmonized and integrated way. In particular, the Satellite Data TCS will deploy five services, EPOSAR, GDM, COMET, 3D-Def and MOD, which are mainly based on the exploitation of SAR data acquired by the Sentinel-1 constellation and designed to provide information on Earth surface displacements. In particular, the planned services will provide both advanced DInSAR products (deformation maps, velocity maps, deformation time series) and value-added measurements (source model, 3D displacement maps, seismic hazard maps). Moreover, the services will release both on-demand and systematic products. The latter will be generated and made available to the users on a continuous basis, by processing each Sentinel-1 data once acquired, over a defined number of areas of interest; while the former will allow users to select data, areas, and time period to carry out their own analyses via an on-line platform. The satellite components will be integrated within the EPOS infrastructure through a common and harmonized interface that will allow users to search, process and share remote sensing images and results. This gateway to the satellite services will be represented by the ESA- Geohazards Exploitation Platform (GEP), a new cloud-based platform for the satellite Earth Observations designed to support the scientific community in the understanding of high impact natural disasters. Satellite Data TCS will use GEP as the common interface toward the main EPOS portal to provide EPOS users not only with data products but also with relevant processing and visualisation software, thus allowing users to gather and process on a cloud-computing infrastructure large datasets without any need to download them locally

We investigate the ground deformation pattern and the source geometry responsible of the 2016 Central Italy seismic sequence (CISS) by joint exploiting the Multisensors and Multiorbits satellite measurements (i.e. Sentinel-1 and ALOS 2) and the integration with the available geological/structural and seismological data. To this purpose we integrate these measurements in a physically-based optimization model scenario. We consider the new seismic sequence that struck Umbria-Marche Apennines (Central Italy) since the month of August 2016. This seismic sequence started with the Amatrice earthquake (MW 6.0) occurred on August 24th. This event nucleated along a SW dipping extensional lineament, called the Mt. Gorzano fault (e.g. Boncio et al., 2004), and caused 299 casualties and severe damages to buildings and historical monuments, devastating Amatrice itself, Accumoli and other surrounding small towns. During the following months, very numerous aftershocks have nucleated and the CISS has migrated northward (e.g. Tinti et al., 2016). On October 26th two intense events occurred with ML 5.4 and ML 5.9, respectively. Moreover, on October 30th the strongest event of the sequence occurred with MW 6.5 close to the small town of Norcia and nucleated along the Mt. Vettore extensional fault (e.g. Galadini & Galli, 2003). The involved area is still active and a lot of earthquake nucleate every day: up to now, the INGV seismic network has recorded more than 30000 events. Despite to the tectonic complexity of the 2016 CISS, we achieved a good determination/description of the ground deformation pattern thanks to the big amount of SAR data acquired by Sentinel-1 (ESA) and ALOS 2 (JAXA) satellites, characterized by small temporal baselines and from different orbits (ascending and descending orbits). In this way, we can analyse in greater detail the ground deformation pattern of the individual seismic events, also decomposing the vertical component and the east-west one. In this context SAR data are a fundamental tool to better understand the spatio-temporal evolution of 2016 CISS. In this context, the present study, benefiting from satellite and in situ information, will investigate, through a numerical optimization multiphysics approach, the most suitable geological scenario that governed the spatial and temporal evolution of the Amatrice-Norcia seismic sequence. References Boncio, P., Lavecchia, G., Milana, G., & Rozzi, B. (2004). "Seismogenesis in Central Apennines, Italy: an integrated analysis of minor earthquake sequences and structural data in the Amatrice-Campotosto area." Annals of Geophysics, vol. 47, issue 6, December 2004. Galadini, F., & Galli, P. (2003). "Paleoseismology of silent faults in the Central Apennines (Italy): the Mt. Vettore and Laga Mts. faults." Annals of Geophysics, vol. 46, issue 5, October 2003. Tinti, E., Scognamiglio, L., Michelini, A., & Cocco, M. (2016). "Slip heterogeneity and directivity of the ML 6.0, 2016, Amatrice earthquake estimated with rapid finite-fault inversion." Geophysical Research Letters, vol. 43, issue 20.

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 (M-w 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 VettoreMount Bove alignment. Additional slip, equivalent to a Mw similar to 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 present the main activities and the most significant results that the Institute for Electromagnetic Sensing of the Environment (IREA) of the National Research Council (CNR) has retrieved within the framework of its collaboration with the Ministry of Economic Development (MiSE) - Directorate- General for Safety of Mining and Energy Activities National Mining Office for Hydrocarbons and Georesources (DGS-UNMIG). In particular, this agreement aims at detecting and monitoring surface deformation affecting the areas of particular interest for the DGS-UNMIG through space-borne Differential SAR (Synthetic Aperture Radar) Interferometry (DInSAR) analysis and multi-parameters and multi-physics modelling. The first ones provide information on the spatial distribution of the retrieved ground displacements and their temporal evolution, the second on the geological/geophysical processes that characterize the investigated areas. In this work, we present the preliminary results retrieved via interferometric analysis performed by exploiting SAR data acquired from the first (ERS-ENVISAT) and second (Sentinel-1) generation sensors over the Emilia-Romagna Region (North Italy) and the entire Italian Peninsula, respectively. Moreover, we performed a 3D geological-structural model of the Cavone site (Emilia-Romagna) and a 3D FEM (Finite Element Method) model for simulating the co-seismic dislocation of the M6.0 and M5.8 seismic events, which occurred on 20/05/2012 and 29/05/2012 over Emilia-Romagna region, respectively.

In the last decades Earth Observation (EO) from space has very fast evolved through the development of remote sensing data-acquisition systems, contributing to the creation of a Big EO Data scenario. In this work, we present a Cloud Computing solution for the advanced interferometric (DInSAR) processing chain based on the Parallel SBAS (P-SBAS) approach, aimed at processing Sentinel-1 (S1) Interferometric Wide Swath (IWS) data for the generation of large spatial scale deformation maps and corresponding displacement time series in an efficient, automatic and systematic way. The presented approach has been used to perform a national-scale DInSAR analysis over Italy, involving the processing of more than 3000 S1 IWS images acquired from both ascending and descending orbits. Details on the cloud infrastructure and processing times will be presented.

Detection and monitoring of deformations affecting cultural heritage sites and their surroundings represent a key issue for developing strategies for their preservation, particularly in the case of extended archaeological areas. In this chapter, we first introduce the differential SAR interferometry (DInSAR) techniques that, thanks to their capability of performing noninvasive deformation analyses, provide valuable information about the spatial and the temporal evolution of the detected displacements. Subsequently, we present the DInSAR results achieved over the whole archaeological site of the ancient Roman city of Pompeii (Italy), and focus on some historical buildings where small displacements, involving portions or the whole complex structure, have been detected. The performed analysis confirms the relevance of the DInSAR techniques for developing sustainable strategies aimed at the preservation of cultural and historical heritage sites.

In this work we present an efficient interferometric processing chain, based on the advanced DInSAR algorithm referred to as Parallel Small BAseline Subset (P-SBAS), for the generation of Sentinel-1A (S1A) Interferometric Wide Swath deformation time-series, which is able to exploit distributed computing architectures. The presented S1A P-SBAS processing chain has been successfully implemented within the ESA Geohazard Exploitation Platform to provide an on-demand automatic service for the unsupervised generation of P-SBAS displacement time-series. To give an idea of the effectiveness of the presented S1A processing chain, as a preliminary result we show a 12-days interferometric analysis at continental scale, carried out by exploiting 150 S1A interferometric pairs acquired over Europe for an overall covered area of about 7,500,000 km2.

On 24 August 2016, at 01:36 UTC¸ the intra-Apennine extensional fault system of Central Italy released a destructive earthquake (MW 6.0). It produced widespread damage and fatalities, killing about 300 people and severely destroying the town of Amatrice and surrounding villages. After few hours, the Amatrice earthquake was followed by a significant aftershock (MW 5.5), which nucleated 15 km NW-ward. The epicentral area of the seismic sequence extends in the NNW-SSE direction, for a length of about 25-30 km. It is located at the hanging-wall of the WSW-dipping Vettore-Gorzano active extensional fault system. During the days following the main shock, a significant number of Synthetic Aperture Radar (SAR) data have been acquired from different passes and angles by the L-band ALOS-2, C-band Sentinel-1 and X-band COSMO-SkyMed satellites. This allowed us to map in a very short time the co-seismic ground displacements through the Differential SAR Interferometry (DInSAR) technique, and also to evaluate their Vertical and East-West components with high details. The generated interferometric pattern is characterized by a double-eyed co-seismic shape that spans 20 km along the NNW-SSE direction and that well coincides with the epicentral areas. We modeled the seismic source that well fit the Mw 6.2 event. In particular, for this analysis, we separately applied an analytical Okada approach as well as a 3D Finite Element (FE) numerical modeling, the latter jointly exploiting DInSAR measurements and structural-geological data. The model obtained via the FE approach suggests that the Amatrice 2016 earthquake nucleated at 8 km deep along the intersection line between the Vettoretto-Redentore and the Northern Gorzano faults, and instantly geminated in two rupture patches that radiated with an approximate bilateral symmetry on the two fault planes. The two rupture patches covered differently shaped slip area, with aspect ratio that well recalls the shape of the interferometric lobes of ground subsidence at the two faults hanging wall. The different shapes of the two lobes are partially associated to the different dip-angle of the Vettoreto-Redentore and Gorzano faults (50° ad 60° respectively). In summary, we found evidences of bilateral rupture propagating along two en-echelon faults connected at the hypocenter.

We investigate the ground deformation and source geometry of the 2016 Amatrice earthquake (Central Italy) by exploiting ALOS2 and Sentinel-1 coseismic differential interferometric synthetic aperture radar (DInSAR) measurements. They reveal two NNW-SSE striking surface deformation lobes, which could be the effect of two distinct faults or the rupture propagation of a single fault. We examine both cases through a single and a double dislocation planar source. Subsequently, we extend our analysis by applying a 3-D finite elements approach jointly exploiting DInSAR measurements and an independent, structurally constrained, 3-D fault model. This model is based on a double fault system including the two northern Gorzano and Redentore-Vettoretto faults (NGF and RVF) which merge into a single WSW dipping fault surface at the hypocentral depth (8 km). The retrieved best fit coseismic surface deformation pattern well supports the exploited structural model. The maximum displacements occur at 5-7 km depth, reaching 90 cm on the RVF footwall and 80 cm on the NGF hanging wall. The von Mises stress field confirms the retrieved seismogenic scenario.