Soil-gas radon anomalies in three study areas of Central-Northern Calabria (Southern Italy)     

G. Iovine  I. Guagliardi  C. Bruno  R. Greco  A. Tallarico  G. Falcone  F. Lucà  G. Buttafuoco 《Natural Hazards》2018,91(1):193-219

Soil-gas radon concentrations and exhalation rates have generally been observed to be anomalously high along active faults in many parts of the world. The soil-gas method is based on the principle that faults and fractures in rocks are highly permeable pathways along which gases can migrate upward from deep crust and mantle to soil cover, retaining their source signatures. The present study summarizes the influence of fault zones on anomalous radon concentrations in soil by integrated geophysical and geo-structural analyses in three study areas of Central-Northern Calabria (Southern Italy). Soil-gas radon surveys have been carried out by means of an alpha scintillation counting system, at 12,509 locations between 2002 and 2004. A geostatistical approach has been used to estimate the spatial distribution of soil radon concentrations. Relations among soil-gas distribution and geo-structural features have been evaluated by ordinary multi-Gaussian kriging. Highest soil radon concentrations (ca. 90 kBq m^?3) have been measured in the Rossanese sector. In the three study areas, no appreciable differences can be noticed among lithotypes, with the highest concentration values (ca. 89 kBq m^?3) measured in alluvial deposit and in clay. Measurements of soil-gas radon reveal anomalies clearly connected to the tectonic structures. Increased signals are linearly distributed along regional WNW–ESE trending shear zones, with main pathways of concentration also recognizable along the E–W fault system in the Rossanese sector, the N–S fault system in the Crati Graben and the Catanzaro Trough, and the NE–SW fault system in the Catanzaro Trough. The distribution of epicentres of historical earthquakes occurred between 1184 and 2001 confirms the recent activity of the same fault systems. Soil-gas radon concentrations generally increase, as expected, with decreasing distance to the faults.  相似文献   

Thermodynamic modeling assisted by multivariate statistical image analysis as a tool for unraveling metamorphic P-T-d evolution: an example from ilmenite-garnet-bearing metapelite of the Peloritani Mountains, Southern Italy     

Patrizia Fiannacca  Deborah Lo Pò  Gaetano Ortolano  Rosolino Cirrincione  Antonino Pezzino 《Mineralogy and Petrology》2012,106(3-4):151-171

An ilmenite-garnet-bearing schist from the medium-grade metapelite complex of the Mandanici Unit in the Peloritani Mountains has been investigated to constrain the P-T conditions attained in this sector of the southern European Hercynian chain. Microprobe investigations assisted by statistical handling of X-ray maps via principal component analysis allowed us to better elucidate the porphyroblast-matrix relationships, the geometry of the elemental distribution in garnet porphyroblasts and the average volume percentage of the reactant garnet during retrograde metamorphic evolution. Selected microprobe data were then used to constrain, by means of P-T pseudosections, the main P-T stages of the metamorphic evolution, using the XRF bulk-rock chemistry as the equilibrium chemical composition for the prograde and peak stages and an effective bulk-rock composition for the retrograde one. Peak metamorphic P-T estimates (~530?°C; 0.9?GPa) are consistent with a Hercynian crustal thickening stage at middle-lower crustal conditions, while subsequent evolution, constrained at 420–460?°C; 0.30–0.60?GPa, depicts a retrograde clockwise P-T trajectory linked to exhumation under likely extensional shearing conditions. The results obtained in this paper lead to envisage a new scenario for the crustal evolution of the Peloritani Mountains and stimulate a revision of previous interpretations in the light of the new investigation techniques.  相似文献   

Foreword to the special issue: the European project UPStrat-MAFA     

Ragnar Sigbjörnsson  Gaetano Zonno  Carlos Sousa Oliveira 《Bulletin of Earthquake Engineering》2016,14(7):1773-1776

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Defining structural robustness under seismic and simultaneous actions: an application to precast RC buildings     

Domenico Asprone  Raffaele De Risi  Gaetano Manfredi 《Bulletin of Earthquake Engineering》2016,14(2):485-499

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Linear versus non-linear earthquake location and seismogenic fault detection in the southern Tyrrhenian Sea, Italy     

D. Presti  B. Orecchio  G. Falcone  G. Neri 《Geophysical Journal International》2008,172(2):607-618

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Alluvial terraces on the Ionian coast of northern Calabria, southern Italy: Implications for tectonic and sea level controls     

Gaetano Robustelli  Federica Luc  Fabio Corbi  Teresa Pelle  Francesco Dramis  Giandomenico Fubelli  Fabio Scarciglia  Francesco Muto  Domenico Cugliari 《Geomorphology》2009,106(3-4):165-179

In this paper we present the results of an integrated geomorphological, pedological and stratigraphical study carried out along the Ionian coast of northern Calabria (southern Italy). This area is characterised by the occurrence of five orders of alluvial terraces that are striking features of the landscape, where large and steep catchments debouch from the mountain front to the hilly coastal belt.Field investigations indicate that the deposits of all five terraces are suggestive of shallow gravel-bed braided streams.On the basis of the age of the Pleistocene substratum and morphostratigraphic correlation with marine terraces cropping out in the nearby areas, each order has been associated to specific marine oxygen isotope stages.Consequently, we focused on the interplay of allocyclic factors influencing stream aggradation/degradation. Soil features and other climatic proxies suggest that climate didn't play an important role with respect to tectonic and base-level changes in controlling fluvial dynamics.In particular, we recognised that during the middle Pleistocene the study area experienced a period of subaerial landscape modelling, as suggested by the thick and complex alluvial sequence of the highest terrace (T1). The onset of regional uplift marks a change in the geomorphic scenario, with tectonic and eustatically driven changes in base-level working together in causing switches in fluvial aggradational/erosional phases (T2–T5 terraces). Because of the uplift, river dissection occurred during phases of sea level fall, whereas aggradation phases occurred during periods of climate amelioration (sea level rise) just before highstands were attained.As a consequence, the stepped terraces in the study area reflect the interplay between tectonics (uplift) and sea level changes, in which terraces define episodes of relative sea level fall during the late Quaternary.  相似文献   

Soil-gas radon anomalies in three study areas of Central-Northern Calabria (Southern Italy)     

Iovine  G.  Guagliardi  I.  Bruno  C.  Greco  R.  Tallarico  A.  Falcone  G.  Luc&#;  F.  Buttafuoco  G. 《Natural Hazards》2017,86(1):193-195

One of the most critical issues in the management of post-earthquake emergency is the prompt identification of the most damaged urban areas. Rapid detection of damage distribution is crucial for Civil Protection during the management of the first emergency phase, in order to both address assistance teams and identify priorities in planning the usability inspections, thus permitting people to go back, as safe as possible, to their houses. Generally, the estimation of building usability is performed by means of a building-by-building survey based on a form to be filled out by expert technicians (Masi et al. 2016). Different countries adopt different forms whose result in terms of usability is dependent essentially on building damage and, in some cases, vulnerability conditions of buildings. When the affected area is large, usability inspections can require a lot of time and a huge number of expert technicians. Therefore, great efforts have been made during past earthquakes in order to define rapid procedures to identify areas not severely damaged and then potentially with a low percentage of unusable buildings. In this framework, many experiences have been carried out worldwide in order to identify, in the immediate aftermath of an earthquake, the damage distribution through remote sensing approaches, possibly combined to field survey data (e.g., Saito and Spence 2004; Yamazaki et al. 2004; Chesnel et al. 2007; Zhai et al. 2016; An et al. 2016; Huang et al. 2016).

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Retrospective Forecasting of M ≥ 4.0 Earthquakes in New Zealand     

R. Console  M. Murru  G. Falcone 《Pure and Applied Geophysics》2010,167(6-7):693-707

We have applied a variation of the Epidemic Type Aftershock Sequence (ETAS) model, which is a stochastic triggering epidemic model incorporating short-term clustering, to data collected by the New Zealand Seismological Observatory-Wellington (Geonet) for forecasting earthquakes of moderate and large magnitude in the New Zealand region. The model uses earthquake data only, with no explicit use of tectonic, geologic, or geodetic information. In this epidemic-type model every earthquake is regarded, at the same time, as being triggered by previous events and triggering following earthquakes. A maximum likelihood estimate of the model parameters has been performed on the learning period from 1960 to 2005 for earthquakes of magnitude 4.0 and larger. Forecast verification procedures have been carried out in a forward-retrospective way on the January 2006 to April 2008 data set, making use of statistical tools as the log-likelihood ratio, the Relative Operating Characteristics (ROC) diagrams, the Molchan error diagrams, the probability gain and the R-score. These procedures show that the clustering epidemic model achieves a log-likelihood ratio per event of the order of some units, and a probability gain up to several hundred times larger than a time-independent spatially uniform random forecasting hypothesis. The results show also that a significant component of the probability gain is linked to the time-independent spatial distribution of the seismicity used in the model.  相似文献   

Analytical versus observational fragilities: the case of Pettino (L’Aquila) damage data database   总被引：2，自引：1，他引：1  

Flavia De Luca  Gerardo M. Verderame  Gaetano Manfredi 《Bulletin of Earthquake Engineering》2015,13(4):1161-1181

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The at-rest earth pressure coefficient prediction using simple elasto-plastic constitutive models     

Antonio Federico  Gaetano Elia  Agnese Murianni 《Computers and Geotechnics》2009,36(1-2):187-198

The paper deals with the theoretical prediction of the at-rest earth pressure coefficient for normally consolidated soils (k_0(NC)) using simple elasto-plastic constitutive models. In the first part of the work, the k_0(NC) expressions derived from critical state soil mechanics models are critically discussed. It is shown that, adopting typical values of the models parameters, the experimental k_0(NC) values are usually over-predicted. In the second part, a possible modification of the critical state model formulation, which allows to predict lower k_0(NC) values for a fixed angle of shearing resistance, is considered. Finally, a discussion of the results and some brief conclusions are proposed.  相似文献