Investigating the time dynamics of monthly rainfall time series observed in northern Lebanon by means of the detrended fluctuation analysis and the Fisher-Shannon method     

Michele Lovallo  Amin Shaban  Talal Darwich  Luciano Telesca 《Acta Geophysica》2013,61(6):1538-1555

We investigate the time dynamics of monthly rainfall series intermittently recorded on seven climatic stations in northern Lebanon from 1939 to 2010 using the detrending fluctuation analysis (DFA) and the Fisher-Shannon (FS) method. The DFA is employed to study the scaling properties of the series, while the FS method to analyze their order/organization structure. The obtained results indicate that most all the stations show a significant persistent behavior, suggesting that the dynamics of the rainfall series is governed by positive feedback mechanisms. Furthermore, we found that the Fisher Information Measure (the Shannon entropy power) seems to decrease (increase) with the height of the rain gauge; this indicates that the rainfall series appear less organized and less regular for higher-located stations. Such findings could be useful for a better comprehension of the climatic regimes governing northern Lebanon.  相似文献   

Visibility Graph Analysis of the 2003–2012 Earthquake Sequence in the Kachchh Region of Western India     

Luciano Telesca  Michele Lovallo  S. K. Aggarwal  P. K. Khan  B. K. Rastogi 《Pure and Applied Geophysics》2016,173(1):125-132

A visibility graph (VG) is a rather novel statistical method in earthquake sequence analysis; it maps a time series into networks or graphs, converting dynamical properties of the time series into topological properties of networks. By using the VG approach, we defined the parameter window mean interval connectivity time <T_c>, that informs about the mean linkage time between earthquakes. We analysed the time variation of <T_c> in the aftershock-depleted catalogue of Kachchh Gujarat (Western India) seismicity from 2003 to 2012, and we found that <T_c>: i) changes through time, indicating that the topological properties of the earthquake network are not stationary; and, ii) appeared to significantly decrease before the largest shock (M5.7) that occurred on March 7, 2006 near the Gedi fault, an active fault in the Kachchh region.  相似文献   

Analysis of long-term fluctuations in stream flow time series: An application to Litani River, Lebanon     

Amin Shaban  Luciano Telesca  Talal Darwich  Nabil Amacha 《Acta Geophysica》2014,62(1):164-179

Litani River is the largest river in Lebanon and has been affected by several physical and anthropogenic factors that influenced its flow dynamics. By means of the Singular Spectrum Analysis (SSA), the time dynamics of the stream flow of seven sites along the course of Litani River was investigated, extracting for each site the long-term trend. A clear decreasing trend characterizes all the long-term trends of the stream flow. Furthermore, several peaks were identified, consistent with the rainfall rate and snow cover variability.  相似文献   

Investigating the Tsunamigenic Potential of Earthquakes from Analysis of the Informational and Multifractal Properties of Seismograms     

Luciano Telesca  Ashutosh Chamoli  Michele Lovallo  Tony Alfredo Stabile 《Pure and Applied Geophysics》2015,172(7):1933-1943

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Effective use of seismic response envelopes for reinforced concrete structures          下载免费PDF全文

Salvatore Sessa  Francesco Marmo  Luciano Rosati 《地震工程与结构动力学》2015,44(14):2401-2423

By exploiting the theory of the response envelopes formulated by Menun and Der Kiureghian [Envelopes for seismic response vectors. I–Theory, J. Str. Engrg. 2000; 126(3); 467–473], an algorithmic approach for seismic analysis of reinforced concrete frames is presented. It aims to fill a gap between research on spectral analysis of structures and current design practice in which the use of seismic response envelopes, available since early 2000s, is hampered by the lack of efficient and robust implementations. The proposed strategy is based on customary features (such as modal shapes and response spectra) currently adopted in professional practice, and it takes advantage of recently published formulations for the evaluation of stress resultants in arbitrarily shaped reinforced concrete cross‐sections subjected to axial force and biaxial bending. Numerical applications are illustrated in order to show the procedure's efficiency and effectiveness. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Facies and palaeosol analysis in a progradational distributive fluvial system from the Campanian–Maastrichtian Bauru Group,Brazil     

Alessandro Batezelli  Francisco Sergio Bernardes Ladeira  Diego Luciano do Nascimento  Mrcio Luiz DA Silva 《Sedimentology》2019,66(2):699-735

The Upper Cretaceous Bauru Group in south‐east Brazil consists of alluvial strata whose characteristics and distribution indicate a fluvial system developed in a semi‐arid to arid climate. Sections exposed within a 90 000 km² study area in Minas Gerais State (in south‐eastern Brazil) were evaluated using facies and palaeosol analysis to formulate depositional and pedogenic models that may account for geomorphic and climate features. From east to west, the study succession records a gradual decrease in grain size, an increase in the width/thickness ratio in channels, a decrease in the lateral and vertical connectivity of channel deposits, and an increase in overbank deposits. The fluvial architecture indicates a braided channel belt, ephemeral ribbon–channels, and an unconfined fluvial facies from east to west in the study area. The lateral and vertical distribution of facies, stratigraphic architecture and palaeocurrent data suggest proximal, medial and distal portions of a progradational distributive fluvial system. The sedimentary dynamics were marked by the building and abandonment of channels related to processes of aggradation, vegetation growth and palaeosol generation. Macromorphological and micromorphological analyses have identified pedological and mineralogical features that indicate an arid to semi‐arid climate with a provenance from the north‐eastern part of the basin (Alto Paranaiba Uplift). From the proximal to the distal portions of the distributive fluvial system, the palaeosol development is different. In the proximal portion, the palaeosols are absent or poorly developed, allowing a possible general comparison with the present soil order: Inceptisols and Aridisols. In the medial portion of the fluvial system, the palaeosols are well‐developed and characterized by Bt, Btk, C and Ck horizons (Alfisols, Aridisols, Inceptisols and Entisols). Poorly drained to well‐drained palaeosols from the base to the top in the distal plain (Aridisols and Inceptisols) are associated with geomorphic and hydromorphic changes in the fluvial system due to progradational evolution. The genetic relationship between the fluvial architecture and the palaeosols enhances the understanding that the sedimentation and pedogenesis that occurs in different portions of the distributive fluvial system are related to the tectonic and climatic evolution of the basin.  相似文献   

The relationship between lunar hot spots and the geomorphic index     

Luciano B. Ronca 《Earth, Moon, and Planets》1970,2(2):202-210

The previously developed geomorphic index of lunar surfaces is applied to the surface distribution of the lunar hot spots. It was found that the hot spot number density is the highest in areas of intermediate geomorphic index, corresponding to mature maria. Young and old maria and the terrae have fewer hot spots per unit area. An hypothesis is presented relating the probability of formation of a hot spot by impact with the evolutionary stage of the regolith of the target surface. The older is the surface, the deeper is the regolith and also the smaller is the average boulder size. For these reasons hot spots will be less probable. The paucity of hot spots in young maria could also be related with the evolution of the regolith, but fundamental changes in the petro-physics of the mare effusions cannot be ruled out.This paper constitutes contribution no. 04 of the Lunar Science Institute and was performed under NASA Contract No. NSR 09-051-001.  相似文献   

Monofractal and multifractal approaches in investigating scaling properties in temporal patterns of the 1983-2000 seismicity in the western Corinth graben, Greece     

Luciano Telesca  Vincenzo LapennaFilippos Vallianatos 《Physics of the Earth and Planetary Interiors》2002,131(1):63-79

Much recent work has been focused on understanding the statistical properties of time-occurrence series of earthquakes. Investigating into the patterns of seismic sequences reveals evidence of scaling features in temporal behavior. This is shown in the clustering properties of seismicity of the western Corinth graben, Greece from 1983 to 2000. Power-law behavior has been found by means of Allan factor analysis and Fourier spectra for the earthquake sequence, with consistent values for the scaling exponents, that decrease with the threshold magnitude. The analysis of the temporal variation of the scaling exponent, performed with different threshold magnitudes, reveals an enhancing of the clusterization in correspondence to larger events. The multifractal analysis of the temporal distribution of the events has shown a decrease of the intermittent character with the threshold magnitude.  相似文献   

Main features of mudslides in tectonised highly fissured clay shales   总被引：1，自引：3，他引：1  

L. Picarelli  G. Urciuoli  M. Ramondini  L. Comegna 《Landslides》2005,2(1):15-30

AbstractMudslides are widespread in the world, especially in areas occupied by highly-fissured plastic stiff clays. Despite their strong impact on structures, infrastructures and, in general, human activity, the knowledge concerning the causes and mechanisms of mudslides is still rather limited. The paper reports some results of long-term research on mudslides in tectonised highly-fissured plastic clay shales carried out through laboratory and in situ tests, monitoring and numerical analyses.  相似文献   

Circulation in the Great Barrier Reef Lagoon using numerical tracers and in situ data     

John L. Luick  Luciano Mason  Thomas Hardy  Miles J. Furnas 《Continental Shelf Research》2007

Numerical hydrodynamic models of the northeastern Queensland shelf, forced by regional winds and modelled boundary currents in the northern Coral Sea, are used to provide improved estimates of general flow trajectories and water residence times within the Great Barrier Reef (GBR) shelf system. Model performance was checked against a limited set of current metre records obtained at Lark Reef (16°S) and the Ribbon Reefs (15.5°S). Estimates of water parcel trajectories are derived from a series of numerical tracer experiments, with daily releases of neutrally buoyant, un-reactive particles at 320 sites along the coast between Cape York (10.7°S) and Hervey Bay (25°S). Flow trajectories and residence times for tracer particles introduced to the GBR lagoon in the southern—ca. 22°S, central—19°S, and northern reef—14°S are emphasised. For purposes of the analysis, the year was divided into two seasons based on mean alongshore current direction. Most coastal sourced tracers entering the central GBR lagoon between 16° and 20°S during the northward-current season (January–August) primarily encounter the outer-shelf reef matrix after exiting the lagoon at its northern “head” (nominally 16°S), after 50–150 days. Up to 70% of tracer particles entering in the southward-current season (August–December) eventually crossed the lagoon to the outer-shelf reef matrix, with median crossing times between 20 and 330 days. During favourable wind conditions, tracers introduced at the coast may move rapidly across the lagoon into the reef matrix. The tracer experiments indicate that most coastal-sourced tracers entering the GBR lagoon remain near the coast for extended periods of time, moving north and south in a coastal band. Residence times for conservative tracer particles (and implied residence times for water-borne materials) within the GBR shelf system ranged from ca. 1 month to 1 year—time frames that are very long relative to development times of planktonic larvae and cycling times for nutrient materials in the water column, implying they are transformed long before reaching the outer reef matrix.  相似文献