Monitoring and structural significance of ground deformations at Campi Flegrei supervolcano (Italy) from the combined 2D and 3D analysis of PS-InSAR, geophysical, geological and structural data

Cities are growing around active volcanoes. Campi Flegrei supervolcano (CF, Italy) is a nested structure formed during two main collapses associated with two caldera-forming eruptions at 39 ka and 15 ka. The last event occurred in AD 1538 (Monte Nuovo volcano). CF hosts 350,000 people and two main uplift phases were recorded in 1968–1972 and 1982–1984 with deformations of about 2 m. The town of Pozzuoli was partially evacuated during the last crisis. Subsequent minor deformations (subsidence and uplift), seismicity, and diffuse CO2 degassing concentrate in the central part of the caldera. Here, we apply the Permanent Scatterers Synthetic Aperture Radar Interferometry (PS-InSAR) to investigate the ground deformations of CF by using data acquired from 1993 to 2007 from ascending and descending tracks by ERS-1 ,ERS-2 and RADARSAT satellites. Deformation maps identify a subsidence interrupted by micro-uplift episodes. These maps are combined with digitized topographic, geological (faults and landslides), seismic, and urbanization data. The merged information allow us to identify the areas involved in the deformation and the volcanotectonic structures activated during the uplift and subsidence episodes. We propose a structural-volcanological model for the unrest pisodes. Data indicate that uplift episodes, which re associated to seismicity, are followed by subsidence episodes accommodated by pre-existing faults. The urbanized areas subjected to the higher deformations and shaking are also identified and mapped. A multi-hazard zonation including landslides is also provided. The approach used here may be utilized to (a) recognize the tectonic and/or volcanic structures activated during ground deformations, (b) to investigate structural models, (c) to evaluate and map multi-risk zonations, and (c) monitor other volcanic areas or nonvolcanic zones subjected to gravity instability or tectonics

Source and dynamics of a volcanic caldera unrest : Campi Flegrei, 1983–84

Acknowledgements We thank Tiziana Vanorio, Antonella Amoruso, Luca Crescentini, Nicholas Rawlinson, Yasuko Takei, and David Cornwell for the valuable suggestions regarding the methodology and interpretation. Reviews from Tim Greenfield and two anonymous reviewers helped improving both clarity of the manuscript and interpretation. The Royal Society of Edinburgh - Accademia dei Lincei Bilateral Agreement, the Santander Mobility Award of the College of Physical Sciences, University of Aberdeen, and the TIDES EU COST action granted L.D.S. travel grants for the realisation of this study. E.D.P. has been supported by the EPHESTO and KNOWAVES projects, funded by the Spanish Ministry of Education and Science.Peer reviewedPublisher PD

Aeromagnetic anomalies reveal hidden tectonic and volcanic structures in the Aeolian Islands, southern Tyrrhenian Sea, Italy

The structures of the Southern Tyrrhenian Sea active volcanoes have been successfully investigated through the use of the magnetic data. Particularly, several high resolution aeromagnetic campaigns have been carried out on the Aeolian Archipelago and its western limit by the Airborne Geophysics Science Team of Istituto Nazionale di Geofisica e Vulcanologia of Roma. The results indicate that the volcanism is controlled by tectonic structures both at local and regional scale. The emplacement of magnetized bodies (e.g. volcanic conduits, dikes swarms, intrusions) is along or strictly correlated with this tectonic framework. The consolidation of highly magnetized material inside the volcanic conduits determines contrast with surrounding less magnetized material producing intense magnetic anomalies. Therefore, modeling of these sources is suggestive of the position and deep extent of eruptive vents, especially in the offshore area, where we do not know where future submarine activity may take place (De Ritis et al., 2005). We present here a case study were the magnetic tool resolved a geological interpretative problem that was not settled earlier. In fact, in the Calabria mainland, widespread, dacitic to rhyolitic pumices with calc-alkaline affinity of Pleistocene age (1-0.7 Ma) are exposed. The tephra falls are related to explosive activity and show thickness decreasing from the Capo Vaticano area southeastward. The lithics indicate a source located not far from Capo Vaticano. The interpretation of the magnetic anomaly field together with the other geological and geophysical data has allowed to discover the presence of a previously unknown volcanic structure (De Ritis et al., 2010), very close to the Calabria Western coast (Capo Vaticano). Aeromagnetic data collected between the Panarea island and the Calabria arc highlight a WNW-ESE elongated positive magnetic anomaly centered on the Capo Vaticano morphological ridge. Forward and inverse modeling show a magnetized body extending from the bathymetric surface to about 3 km of depth. The magnetic properties of such a body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc, i.e. dacites and rhyolites. The combined interpretation of the magnetic and available geological data reveal that (1) the Capo Vaticano WNW- ESE elongated positive magnetic anomaly is due to the occurrence of a WNW-ESE elongated sill; (2) such a sill represents the remnant of the plumbing system of a Pleistocene volcano that erupted explosively producing the pumice tephra exposed in Calabria; and (3) the volcanism is consistent with the Aeolian products, in terms of age, magnetic signature, and geochemical affinity of the erupted products. The results indicate that such volcanism developed along seismically active faults transversal to the general trend of the Aeolian Arc and Calabria block, in an area where uplift is maximized (4 mm/yr). Such uplift could also be responsible for fragmentation of the upper crust and formation of transversal faults along which seismic activity and volcanism occur

Morphometry of the Campi Flegrei caldera (Southern Italy)

A high-resolution Digital Terrain Model (DTM) of Campi Flegrei caldera, obtained from an airborne LiDAR mission, has been analyzed in order to produce a 1:20,000-scale morphometric map of this volcanic area. The map consists of different thematic layers, which include: profile curvature, terrain ruggedness index, elevation range, as well as an up-to-date structural map and building distribution in the densely populated area. Results evidence that most of the relief is related to the occurrence of tuff-cones, tuff-ring, and the outer flanks of the caldera. Higher values of elevation characterize the upper portions of cones, while higher terrain ruggedness index values concentrate on the inner flanks of cones and in areas affected by gravity and erosional processes. The map also evidences the topographic expression of crater rims and of the major morphological scarps, which reflect ancient and uplifted shorelines and present-day cliffs

Equidad en el acceso a la educación de calidad.

El siguiente artículo, toma como base el documento del IV encuentro del foro de Vicepresidente de América central y Dominicana Equidad en el acceso a la educación de calidad evaluando contenidos como: La historia de la equidad y calidad de educación, la evaluación de los progresos y desafíos, Agenda educativa estratégica centroamericana, educación inicial, la definición de las escuelas en los países centroamericanos, la participación social, La educación superior y especializada de alta calidad y su papel en la sociedad del conocimiento, Finalmente, se insiste en que la superación de los problemas educativos que atraviesa la región, los desafíos y metas pendientes, solo es posible encararlos de manera coordinada en el marco de alianzas regionales y de una integración educativa regional

Estimates of fluid pressure and tectonic stress in hydrothermal/volcanic areas:a methodological approach

An analytical approach to estimate the relative contribution of the fluid pressure and tectonic stress in hydrothermal/ volcanic areas is proposed assuming a Coulomb criterion of failure. The analytical procedure requires the coefficient of internal friction, cohesion, rock density, and thickness of overburden to be known from geological data. In addition, the orientation of the principal stress axes and the stress ratio must be determined from the inversion of fault-slip or seismic data (focal mechanisms). At first, the stress magnitude is calculated assuming that faulting occurs in 'dry' conditions (fluid pressure=0). In a second step, the fluid pressure is introduced performing a grid search over the orientation of 1) fault planes that slip by shear failure or 2) cracks that open under different values of fluid pressure and calculating the consistency with the observed fault planes (i.e. strike and dip of faults, cracks, nodal planes from focal mechanisms). The analytical method is applied using fault-slip data from the Solfatara volcano (Campi Flegrei, Italy) and seismic data (focal mechanisms) from the Vesuvius volcano (Italy). In these areas, the fluid pressure required to activate faults (shear fractures) and cracks (open fractures) is calculated. At Solfatara, the ratio between the fluid pressure and the vertical stress ?is very low for faults ( ?=0.16) and relatively high for cracks ( ?=0.5). At Vesuvius, ?=0.6. Limits and uncertainties of the method are also discussed

High-resolution morpho-bathymetry of the Gulf of Naples, Eastern Tyrrhenian Sea

ABSTRACTWe present a high-resolution bathymetric map of the Gulf of Naples (Italy), which is surrounded by the two main volcanic complexes of Mt. Somma-Vesuvius and Phlegrean Fields. The morphology is obtained from swath bathymetric in a Digital Terrain Model with a 5 m grid cell size. Bathymetric data display the main seafloor morphologies with a resolution never obtained before. These morphologies include the Ammontatura and Dohrn Canyons, the Penta Palummo, Nisida, Miseno and Banco della Montagna banks, and the bathymetric features of the submerged sector of the Somma-Vesuvius volcano. Overall, a prevailing volcanic nature characterizes the seafloor morphologies located in the northern sector, while the southern one is dominated by sedimentary features. The Final Map could be useful for the evaluation of the volcano-related hazards in the area

Comparison of multi-state Markov models for cancer progression with different procedures for parameters estimation. An application to breast cancer

Background: the knowledge of sojourn time (the duration of the preclinical screen-detectable period) and screening test sensitivity is crucial for understanding the disease progression and the effectiveness of screening programmes. For this purpose a model of the natural history of the disease is needed. The aim of this work is to provide an illustration of the application of multistate Markov models for breast cancer progression to the data of the Florentine screening programme, in order to estimate the sojourn time and sensitivity for breast cancer screening. Methods: three different multi-state Markov models of increasing complexity were used with three different estimation procedures based on non-linear least squares, maximum likelihood, and on a Bayesian approach. All the models produced estimates for screening sensitivity and mean sojourn time. The data used in our application seem to lead to a non-identifiability problem, since the estimation procedures for both the Maximum Likelihood and Non-Linear Least Squares gave estimates that changed with the parameters’ initial values or difficultly converged. In order to take this problem into account we used the Bayesian Approach by incorporating prior information on all the parameters. Results: the mean sojourn time varied between 2-7 years and 3-5 years for women aged 50-59 and 60-69, respectively. When the model complexity was increased a higher variability in estimates was observed among the estimation procedures. The results of the screening sensitivity estimates were highly variable, both among estimation techniques and models - varying between 63% and 100%, and between 77% and 100% for women aged 50-59 and 60-69, respectively. Conclusions: results are in accord with the literature; those obtained through the Bayesian Approach seem to be more reliable.&nbsp

Epididymal adrenal rest in an orchiectomy specimen with seminoma

Ectopic adrenal tissue is rare but is reported in various locations within the urogenital tract and abdominal structures. The vast majority of adrenal rests represent incidental findings in surgical specimens; thus, their incidence is unknown.1 Notwithstanding, the results of reports on their higher frequency in infants than adults and sex distribution are conflicting.1,2 In male subjects, the paratesticular and inguinal regions represent common sites of ectopic adrenal tissue, given the intimate embryologic relationship between the gonad and the adrenal cortex.3 In testis and paratestis, they are also known as Marchand rest and are most commonly found in the spermatic cord,3 followed by testis4 and epididymis.5,6 In these anatomic locations, ectopic adrenals may be associated with undescended testis, inguinal hernia, epididymal abnormality, and spermatic cord torsion, but none represent a predisposing factor. Also, the association with malignant testicular neoplasms merely represents a matter of chance. As a rule, adrenal rests do not show significant clinical implications. However, they may undergo hyperplasia when the function of the main adrenals is deficient or in congenital adrenal hyperplasia (CAH), an autosomal recessive disease with increased ACTH levels.5,6 Also, adrenal rests may be accidentally removed during surgery, leading to adrenal insufficiency. Finally, ectopic adrenal may harbor benign or malignant tumors resulting in clinically evident dysfunctions.3 The adrenal rests comprise nodules ranging between 1 mm and 1 cm, appearing as encapsulated or well-circumscribed round yellowish masses that may be multiple or bilateral. Microscopic appearance reminds normal adrenal cortex, often arranged in different zones, without medullary tissue.Figure 1 refers to a case of a tiny adrenal rest nodule incidentally observed in an orchiectomy specimen obtained from a 40-year-old man affected by a suspect germ cell tumor of the right testis. The surgical specimen´s gross examination depicted a yellowish-brown nodule measuring 2 mm in its longest axis, located under the visceral mesothelium of the tunica vaginalis near the head of the epididymis (Figure 1A).Figure 1A - Gross orchiectomy specimen displaying a tiny nodule yellowish-brown in color (arrowhead) below the visceral layer of the tunica vaginalis and close to the head of the epididymis (scale bar= 3 cm); B - Encapsulated adrenal rest located between epididymis and rete testis; C - Encapsulated adrenal cortical tissue; D - Immunohistochemical positivity for Melan-A.: Microscopical examination diagnosed a pure testicular seminoma infiltrating the albuginea and the visceral part of the tunica vaginalis (pT2). Histology showed a well-encapsulated nodule between the epididymis head and the rete testis (Figure 1B). The nodule was composed of epithelial cells arranged into an organoid pattern consistent with the adrenal cortex (Figure 1C). No adrenal medullary tissue was present. The cells were immunohistochemically positive for Melan-A monoclonal antibody (clone A103) (Figure 1D). No immunostaining was observed for inhibin α (clone R1), calretinin (clone DAK-Calret 1), and BCL2 oncoprotein (clone 124)

Inverse Modelling of the Reversely Magnetized, Shallow Plumbing System Hosting Oil Reservoirs of the Auca Mahuida Volcano (Payeina retroarc, Neuquén Basin, Argentina)

The Auca Mahuida volcano (2.03–0.88 Ma) located east of the Andean thrust front in the Neuquén basin (Argentina) hosts an oil system of thermogenic origin and is affected by the NW–SE striking-faults. Intrusive bodies and the underlying Jurassic sediments constitute the reservoir rocks. Aeromagnetic data collected in the Auca Mahuida area detected multiple dipolar magnetic anomalies, many of which have reverse polarity. Palaeomagnetic measurements on rock samples collected in the field together with available age determinations indicate that the reversely magnetized sources were mainly emplaced during the Matuyama reverse polarity chron while the normal polarity sources were emplaced during the Olduvai and/or Jaramillo subchrons. The location and geometry of the intrusive bodies is poorly known and the customary magnetic inversion is rendered difficult because of multiple natural remanent magnetization directions. To address these difficulties, a voxel inversion was applied to model the vector residual magnetic intensity (VRMI) transformation of the observed total magnetic intensity data. The modelling showed a 1.5 km deep, subcircular ring-shaped intrusion below the summit of the volcano and a series of NW–SE elongated, fault-controlled intrusive bodies to depths up to 3–4 km. Our results show that magnetic data and VRMI modelling help resolve the geometry of the shallow plumbing system of volcanoes with remanently magnetized sources, and estimate the depth and geometry of potential oil reservoirs in volcanic areas