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Monitoraggio di medio-lungo termine dell'area urbana di Maierato (frana del 15 febbraio 2010 e dintorni) con dati COSMO-SkyMed

Manyurbanareasallovertheworldareaffectedbyawidespectrumofdangersrelatedtoeithernaturalphenomena or human activities. Among natural phenomena, slow-moving landslides are widespread and their interaction with the urban environment often originate detrimental effects to existing facilities (e.g., buildings and infrastructures) withrelatedsocialconsequencesandeconomiclosses.Forthesereasons,landslidehazardandvulnerabilityanalysesrepresentkeystepsforareliablepredictionoftheexpecteddamagetoexposedfacilitiesaswellasforproperly designing and implementing the most suitable risk mitigation strategies. Synthetic Aperture Radar (SAR) data processed via advanced interferometric techniques (DInSAR), such as the onebasedontheuseofSARTomography,canbeextremelyusefulinprovidinglong-termground/facilitydisplacementarchives.Inthisregard,theavailabilityofrecenthigh-resolutionX-BandSARdatapromotedthemonitoring capabilities in urban environments, leading to a major step toward the risk analysis at single facility level. In this study, with reference to an urban area located in Calabria region (southern Italian Apennines) - were the existence of several slow-moving landslides of different types interacting with masonry and reinforced concrete buildings can be recognized - the DInSAR-derived differential settlements experienced by a given building are combined with the corresponding damage severity level (recorded via in-situ surveys) to retrieve the relationship between cause (differential settlements) and effect (damage) for both masonry and reinforced concrete buildings. The obtained results represent the knowledge basis to generate more sophisticated tools (e.g. fragility and vulnerability curves) useful for risk analysis purposes.

High and very-high resolution remote sensing data provided by the processing of Synthetic Aperture Radar (SAR) images via Differential Interferometry techniques (DInSAR) allow detecting ground surface displacements that can be used in monitoring/control of urban areas and integrated within procedures aimed at analyzing the vulnerability of affected facilities (e.g. structures and infrastructure). In this regard, this paper presents the results of a study that combines DInSAR data and information gathered from damage surveys to buildings interacting with slow-moving landslides. In particular, relationships between cause (DInSAR-derived differential settlements of buildings) and effect (recorded building damages) are retrieved and empirical fragility and vulnerability curves (to be used for damage forecasting purposes) are generated. Considering the encouraging outcomes, the adopted methodological approach can be successfully integrated within a more general framework for the management of slow-moving landslide risk to which urban areas are exposed.

Here we present the results of the inversion of a new geodetic data set covering the 2012 Emilia seismic sequence and the following 1 year of postseismic deformation. Modeling of the geodetic data together with the use of a catalog of 3-D relocated aftershocks allows us to constrain the rupture geometries and the coseismic and postseismic slip distributions for the two main events (M-w 6.1 and 6.0) of the sequence and to explore how these thrust events have interacted with each other. Dislocation modeling reveals that the first event ruptured a slip patch located in the center of the Middle Ferrara thrust with up to 1 m of reverse slip. The modeling of the second event, located about 15 km to the southwest, indicates a main patch with up to 60 cm of slip initiated in the deeper and flatter portion of the Mirandola thrust and progressively propagated postseismically toward the top section of the rupture plane, where most of the aftershocks and afterslip occurred. Our results also indicate that between the two main events, a third thrust segment was activated releasing a pulse of aseismic slip equivalent to a M-w 5.8 event. Coulomb stress changes suggest that the aseismic event was likely triggered by the preceding main shock and that the aseismic slip event probably brought the second fault closer to failure. Our findings show significant correlations between static stress changes and seismicity and suggest that stress interaction between earthquakes plays a significant role among continental en echelon thrusts.

We show the results of the inversion of a new geodetic dataset, involving both remote sensing and ground-based data: high precision levelling data, GPS observations and Differential Synthetic Aperture Radar Interferometry (DInSAR) products covering the 2012 Emilia seismic sequence and the following one year of post-seismic deformation. As far as DInSAR analysis, we used data acquired by the RADARSAT-2 (RSAT2) satellite from the Canadian Space Agency and by the COSMO-SkyMed (CSK) constellation developed by the Italian Space Agency in cooperation with the Ministry of Defense. For what attains the RSAT2 mission, we considered a single interferometric pair only, involving the 30 April and 17 June 2012 stripmap acquisitions, aimed at measuring the cumulative coseismic ground displacement due to the two mainshocks (20 and 29 May 2012). As for the CSK mission, a dataset of 12 stripmap images covering a time interval of almost one year, from 27 May 2012 to 7 May 2013, allowed measuring the coseismic displacement field relevant to the 29 May mainshock as well as one year of post-seismic deformation. To retrieve the CSK deformation time series relevant to the post-seismic sequence, we applied the Small BAseline Subset (SBAS) algorithm [Berardino et al., 2002], specifically the one in Fornaro et al. [2009]. By use of the geodetic dataset together with a catalog of relocated aftershocks, we modeled rupture geometries, and the coseismic and post-seismic slip distributions for the two main events (MW 6.1 and 6.0) of the sequence, allowing us to suggest the influence of structure and/or lithology on slip propagation in intracontinental settings. Moreover, we explored how these thrust events have interacted with each other and, defining the Coulomb stress changes, how first mainshock triggered following activity. Our results also indicate that between the two main events, a third thrust segment was activated by first mainshock, releasing a pulse of aseismic slip equivalent to a MW 5.8 event. We also hypothesized that the aseismic slip event probably brought the second fault closer to failure. Generally, we found that among continental en echelon thrusts, stress transfer and interaction between earthquakes and aseismic slip may play an important role in the way they activate during a seismic sequence. References Berardino, P., Fornaro, G., Lanari, R. and Sansosti, E (2002). A new algorithm for surface deformation monitoring based on small baseline differential SAR interferograms, IEEE Trans. Geosci. Remote Sens., 40, 2375-2383 Fornaro, G., Pauciullo, A. and Serafino, F. (2009). Deformation monitoring over large areas with multipass differential SAR interferometry: a new approach based on the use of spatial differences, Int. J. Remote Sens., 30, 1455-1478.

Nel febbraio del 2010, e nell'inverno 2008-2009, numerose aree urbane della Calabria sono state interessate da diffusi fenomeni di frana. Fra queste il popoloso quartiere di Ianò, nel comune di Catanzaro, dove si determinò una grave condizione di emergenza. L'area di interesse risulta in larga parte classificata a rischio molto elevato (R4) nel PAI Calabria. Per le finalità indicate nell'Ordinanza P.C.M. n. 3862/2010 e negli approfondimenti successivi, sono stati condotti rilievi, indagini e monitoraggi. L'area su cui insiste il quartiere di Ianò, a Nord del centro di Catanzaro, è caratterizzata dalla presenza di creste costituite dalle testate di strato di arenarie e di concavità morfologiche riempite da colluvioni. Le frane presenti sono del tipo scorrimento roto-traslazionale, a volte con evoluzione in colata della porzione terminale. In particolare, le frane del febbraio 2010 sono prevalentemente riattivazioni parziali di fenomeni franosi preesistenti. Per finalità conoscitive e per supportare la gestione della fase di post-emergenza è stata realizzata una rete integrata di monitoraggio (verticali attrezzate con piezometri e con tubi inclinometrici, capisaldi GPS). L'attività di monitoraggio ha tratto beneficio dall'elaborazione di una serie di immagini radar ad apertura sintetica (SAR), acquisita dal satellite TerraSAR-X, attraverso tecniche di Interferometria Differenziale. L'uso dell'approccio interferometrico ha condotto alla stima di mappe di spostamento sull'intera area di interesse, con accuratezze sub-centimetriche e risoluzioni spaziali dell'ordine di 2 m. Nella nota, partendo da una valutazione del rischio residuo da frana condotta su base geologico-geomorfologica, sono proposti alcuni semplici criteri per integrare progressivamente nella stessa valutazione le indicazioni desumibili dall'elaborazione di dati satellitari e dal monitoraggio geotecnico degli spostamenti.

The inversion of multitemporal DInSAR and GPS measurements unravels the coseismic and postseismic (afterslip) slip distributions associated with the 2009 M-W 6.3 L'Aquila earthquake and provides insights into the rheological properties and long-term behavior of the responsible structure, the Paganica fault. Well-resolved patches of high postseismic slip (10-20 cm) appear to surround the main coseismic patch (maximum slip approximate to 1 m) through the entire seismogenic layer above the hypocenter without any obvious depth-dependent control. Time series of postseismic displacement are well reproduced by an exponential function with best-fit decay constants in the range of 20-40 days. A sudden discontinuity in the evolution of released postseismic moment at approximate to 130 days after the main shock does not correlate with independent seismological and geodetic data and is attributed to residual noise in the InSAR time series. The data are unable to resolve migration of afterslip along the fault probably because of the time interval (six days) between the main shock and the first radar acquisition. Surface fractures observed along the Paganica fault follow the steepest gradients of postseismic line-of-sight satellite displacements and are consistent with a sudden and delayed failure of the shallow layer in response to upward tapering of slip. The occurrence of afterslip at various levels through the entire seismogenic layer argues against exclusive depth-dependent variations of frictional properties on the fault, supporting the hypothesis of significant horizontal frictional heterogeneities and/or geometrical complexities. We support the hypothesis that such heterogeneities and complexities may be at the origin of the long-term variable behavior suggested by the paleoseismological studies. Rupture of fault patches with dimensions similar to that activated in 2009 appears to have a approximate to 500 year recurrence time interval documented by paleoseismic and historical studies. In addition to that, paleoseismological evidence of large (>0.5 m) coseismic offsets seems to require seismic events, recurring every 1000-2000 years, characterized by (1) multisegment linkage, (2) surface ruptures larger than in 2009, and (3) complete failure of the 2009 coseismic and postseismic patches.

Summary The immunohistochemical features of 5 ductal adenomas of the breast were investigated. The tumours were composed by tubular glands lined by cells with both luminal and basalt/myoepithelial immunophenotypes. Tubules were encircled by an intact basement membrane as demonstrated by staining for laminin and type IV collagen. Areas of dense fibrosis, a usual finding in these lesions, stained for fibronectin, type III collagen and contained vimentin and actin positive spindle cells, consistent with myofibroblasts. These observations confirm a double epithelial and myoepithelial differentiation in these lesions and seem to support the suggestion that ductal adenomas result from sclerosis of ductal papillomas.

We report a case of oesophageal carcinosarcoma with prominent rhabdomyoblastic differentiation. Immunohistochemically, the rhabdomyblasts were mainly reactive to vimentin, cytokeratin, desmin, muscle-specific actin, myosin, and myoglobin, and were surrounded by laminin and type IV collagen-positive basement membranes. The tumour had dual differentiation, carcinomatous and sarcomatous, but also showed evident features of transition between the two components; suggesting a common origin. An epithelial-mesenchymal conversion could be the pathogenetic mechanism involved in the histogenesis of this lesion. The word carcinosarcoma, from a descriptive point of view, seems the most suitable to describe a tumour composed of both carcinomatous and true sarcomatous elements.

Four-dimensional synthetic aperture radar (SAR) imaging, also known as differential SAR tomography, is a new research topic in the framework of coherent multitemporal/multibaseline SAR processing that extends the interferometry concept. Four-dimensional SAR imaging-based processing could improve the capability of ground-scatterer monitoring with respect to classical differential interferometric SAR processing. The first results on the applicability of such an advanced tomographic SAR processing to real spaceborne data were recently discussed in the literature. In this letter, we present the results of an experiment with a data set that demonstrates the potentialities of this new technique for monitoring complex targets, such as infrastructures.

In this letter, an analytical description of the 2-D and 3-D imaging of ground-based synthetic aperture radar data is given. The ability of the 3-D imaging to separate targets along the elevation direction will also be shown, thus allowing their complete localization in space. The validation of the proposed method is done by exploiting simulated data.

The superposition of contributions from different stable targets within the same pixel is a phenomenon that may impair the imaging and monitoring of ground scatterers via the multipass synthetic aperture radar (SAR) interferometry technique. Three-dimensional SAR imaging, also known as SAR tomography, uses multiple views to profile the scattering power at different heights. This technique has been shown to be capable of separating interfering target responses on real data. Differential SAR tomography has been recently proposed as a technique that extends the potentialities of SAR tomography to the target deformation monitoring. It performs a 4-D space-velocity imaging that enables not only separating interfering targets in elevation but also distinguishing their single slow deformation velocities. This work addresses for the first time the application of 4-D SAR imaging to real data to determine the height and mean deformation velocity of single scatterers and double-scattering mechanisms interfering at high resolution in the same pixel. It also discusses the postprocessing steps required to identify the presence of stable single and double scatterers after elevation-velocity focusing. Moreover, it proposes a technique for the extraction of time series from interfering targets to measure possible nonlinear temporal deformations.