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Alexander Eleftheriou Carolina Filizzola Nicola Genzano Teodosio Lacava Mariano Lisi Rossana Paciello Nicola Pergola Filippos Vallianatos Valerio Tramutoli 《Pure and Applied Geophysics》2016,173(1):285-303
Real-time integration of multi-parametric observations is expected to accelerate the process toward improved, and operationally more effective, systems for time-Dependent Assessment of Seismic Hazard (t-DASH) and earthquake short-term (from days to weeks) forecast. However, a very preliminary step in this direction is the identification of those parameters (chemical, physical, biological, etc.) whose anomalous variations can be, to some extent, associated with the complex process of preparation for major earthquakes. In this paper one of these parameters (the Earth’s emitted radiation in the Thermal InfraRed spectral region) is considered for its possible correlation with M ≥ 4 earthquakes occurred in Greece in between 2004 and 2013. The Robust Satellite Technique (RST) data analysis approach and Robust Estimator of TIR Anomalies (RETIRA) index were used to preliminarily define, and then to identify, significant sequences of TIR anomalies (SSTAs) in 10 years (2004–2013) of daily TIR images acquired by the Spinning Enhanced Visible and Infrared Imager on board the Meteosat Second Generation satellite. Taking into account the physical models proposed for justifying the existence of a correlation among TIR anomalies and earthquake occurrences, specific validation rules (in line with the ones used by the Collaboratory for the Study of Earthquake Predictability—CSEP—Project) have been defined to drive a retrospective correlation analysis process. The analysis shows that more than 93 % of all identified SSTAs occur in the prefixed space–time window around (M ≥ 4) earthquake's time and location of occurrence with a false positive rate smaller than 7 %. Molchan error diagram analysis shows that such a correlation is far to be achievable by chance notwithstanding the huge amount of missed events due to frequent space/time data gaps produced by the presence of clouds over the scene. Achieved results, and particularly the very low rate of false positives registered on a so long testing period, seems already sufficient (at least) to qualify TIR anomalies (identified by RST approach and RETIRA index) among the parameters to be considered in the framework of a multi-parametric approach to t-DASH. 相似文献
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Christian Pin Eladio Lin Emilio Pascual Teodosio Donaire Alfonso Valenzuela 《Tectonophysics》2002,352(1-2)
Because the Hercynian overprint was extremely weak, the Sierra de Córdoba (southeastern Ossa-Morena Zone, OMZ) provides an excellent opportunity to study the tectonic evolution of sequences deposited close to the Late Neoproterozoic–Early Palaeozoic boundary. In order to put constraints on the sources and geodynamic significance of the Late Proterozoic magmatism, a representative set of 18 igneous rocks, and 3 interbedded sedimentary rocks from the San Jerónimo Formation have been studied for major and trace element geochemistry and for the Sm–Nd isotopic systematics. The igneous rocks are generally porphyritic to microporphyritic andesites, with abundant plagioclase (±amphibole) phenocrysts. With the exception of two intrusive rocks, possibly not related to the Late Proterozoic episode, all the samples display positive Nd550 Ma values, ranging from +2.9 to +7.6. Most of them, with +4<Nd550 Ma<+6, exhibit LREE enrichment, high La/Nb ratios, and elevated Zr/Nb ratios ranging from 21 to 32. There is no obvious correlation between the shape of REE patterns, La/Nb ratios and Nd550 Ma values, precluding simple models of late-stage interaction with typical crustal components having low Nd and high LREE/HREE and La/Nb ratios. Based on their major element composition and enriched, continental crust-like trace element characteristics, combined with distinctly positive Nd initial values, the Córdoba andesites document an episode of crustal growth through the addition of calc-alkaline magmas, extracted from a mantle reservoir which was strongly depleted in LREE on a time-integrated basis. The occurrence of interlayered sediments of continental provenance (negative Nd values) does not favour a purely ensimatic arc setting, remote from continental land masses, for this subduction-related magmatism, but the geochemical data suggest an active margin environment located on relatively juvenile crust. In any case, the Córdoba andesites document the addition of materials chemically similar to the bulk continental crust which were extracted from mantle sources with strong time-integrated LREE depletion. Therefore, they provide evidence for crustal growth related to Cadomian orogenic events during Late Proterozoic times. 相似文献
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Marouane Temimi Teodosio Lacava Tarendra Lakhankar Valerio Tramutoli Hosni Ghedira Riadh Ata Reza Khanbilvardi 《水文研究》2011,25(16):2623-2634
The objective of this work is to demonstrate the potential of using passive microwave data to monitor flood and discharge conditions and to infer watershed hydraulic and hydrologic parameters. The case study is the major flood in Iowa in summer 2008. A new Polarisation Ratio Variation Index (PRVI) was developed based on a multi‐temporal analysis of 37 GHz satellite imagery from the Advanced Microwave Scanning Radiometer (AMSR‐E) to calculate and detect anomalies in soil moisture and/or inundated areas. The Robust Satellite Technique (RST) which is a change detection approach based on the analysis of historical satellite records was adopted. A rating curve has been developed to assess the relationship between PRVI values and discharge observations downstream. A time‐lag term has been introduced and adjusted to account for the changing delay between PRVI and streamflow. Moreover, the Kalman filter has been used to update the rating curve parameters in near real time. The temporal variability of the b exponent in the rating curve formula shows that it converges toward a constant value. A consistent 21‐day time lag, very close to an estimate of the time of concentration, was obtained. The agreement between observed discharge downstream and estimated discharge with and without parameters adjustment was 65 and 95%, respectively. This demonstrates the interesting role that passive microwave can play in monitoring flooding and wetness conditions and estimating key hydrologic parameters. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Shaking table tests of a reinforced concrete waffle–flat plate structure designed following modern codes: seismic performance and damage evaluation 
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下载免费PDF全文 Shaking table tests were conducted on a scaled reinforced concrete waffle–flat plate structure. It represented a conventional construction design under current building codes in the Mediterranean area. The test structure was subjected to a sequence of four seismic simulations of increasing magnitude. Each simulation was associated with a seismic hazard level characterized by the mean return period PR. The test structure performed well for the simulations associated with PR = 95, 475 and 975 years but collapsed under the maximum considered earthquake of PR = 2475 years. Damage concentrated at column bases, where the maximum chord rotation reached 93% of the ultimate capacity, and at the transverse beams of the exterior plate‐to‐column connection that failed in torsion. It is shown that most (from 85% to 90%) of the energy input by the earthquake that contributes to damage is dissipated by the plate. The capacity curve of the tested structure estimated from the experimental base shear vs. top displacement relationship allowed us to compute the overstrength (1.4). It is close to the maximum established by European code EN 1998‐1 (1.5). Based on a detailed study of the test results, potential updates to current codes and design recommendations are suggested. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Microgranular enclaves as evidence of rapid cooling in granitoid rocks: the case of the Los Pedroches granodiorite,Iberian Massif,Spain 总被引：13，自引：2，他引：11
Teodosio?DonaireEmail author Emilio?Pascual Christian?Pin Jean-Louis?Duthou 《Contributions to Mineralogy and Petrology》2005,149(3):247-265
Microgranular enclaves from the Los Pedroches granodiorite (LPG) (Los Pedroches Batholith, Iberian Massif, Spain) have Sr-Nd isotopic and mineral chemical compositions close to those of their host. This similarity is not related to restite unmixing, as indicated by the igneous textures of the enclaves. A number of other geological and geochemical lines of evidence, including the high REE and HFSE contents of the microgranular enclaves relative to the host granitoid, strongly suggest that this similarity cannot be explained by magma mixing. Alternatively, a crystallization process by rapid cooling within the host granitoid magma could explain the geochemical and textural characteristics of the microgranular enclaves, including shape, grain size, mineralogy, texture, chemistry and Sr-Nd isotopic composition. Such a crystallization occurred at the walls of the magma conduits through which the granitic magmas were emplaced in the upper crust. This process should be considered as an alternative hypothesis to magma mixing for the generation of some microgranular enclaves, especially where no direct evidence exists for the presence of basic magmas coeval with granitoids, and where there is a lack of isotopic contrast between hosts and enclaves. As the process is favoured by feeder-dyke related emplacement, we suggest that abundance of microgranular enclaves can be related to the mechanism of emplacement of granitoid bodies.This revised version was published online in March 2005 with corrections to the accepted date.
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