Empirical relationships between aftershock area dimensions and magnitude for earthquakes in the Mediterranean Sea region     

Konstantinos I. Konstantinou  Gerassimos A. Papadopoulos  Anna Fokaefs  Katerina Orphanogiannaki 《Tectonophysics》2005,403(1-4):95-115

Fault dimension estimates derived from the aftershock area extent of 36 shallow depth (≤ 31 km) earthquakes that occurred in the Mediterranean Sea region have been used in order to establish empirical relationships between length, width, area and surface-wave/moment magnitude. This dataset consists of events whose aftershock sequence was recorded by a dense local or regional network and the reported location errors did not exceed on average 3–5 km. Surface-wave magnitudes for these events were obtained from the NEIC database and/or published reports, while moment magnitudes as well as focal mechanisms were available from the Harvard/USGS catalogues. Contrary to the results of some previously published studies we found no evidence in our dataset that faulting type may have an effect on the fault dimension estimates and therefore we derived relationships for the whole of the dataset. Comparisons, by means of statistical F-tests, of our relationships with other previously published regional and global relationships were performed in order to check possible similarities or differences. Most such comparisons showed relatively low significance levels (< 95%), since the differences in source dimension estimates were large mainly for magnitudes lower than 6.5, becoming smaller with increasing magnitude. Some degree of similarity, however, could be observed between our fault length relationship and the one derived from aftershock area lengths of events in Greece, while a difference was found between our regional and global fault length relationships. A calculation of the ratio defined as the fault length, derived from our relationships, to the length estimated from regional empirical relationships involving surface ruptures showed that it can take a maximum value of about 7 for small magnitudes while it approaches unity at Ms 7.2. When calculating the same ratio using instead global empirical relationships we see the maximum value not exceeding 1.8, while unity is reached at Mw 7.8, indicating the existence of a strong regional variation in the fault lengths of earthquakes occurring in the Mediterranean Sea region. Also, a relationship between the logarithms of the rupture area and seismic moment is established and it is inferred that there is some variation of stress drop as a function of seismic moment. In particular, it is observed that for magnitudes lower than 6.6 the stress drop fluctuates around 10 bar, while for larger magnitudes the stress drop reaches a value as high as 60 bar.  相似文献   

Organization of Emergency Response After a Major Disaster Event in an Urban Area with the Help of an Automatic Vehicle Location and Control System   总被引：3，自引：0，他引：3  

Paraskevas Savvaidis  Konstantinos Lakakis  Ioannis Ifadis 《GPS Solutions》2002,5(4):70-79

The quick response of civil authorities after a major disaster event in an urban area is essential for the reduction of damages and impacts to human lives. One of the first critical problems to be solved at the very early stages of response is the optimum management of emergency vehicles and real time knowledge of the accessibility of the road network. In this article the concept of using a number of emergency vehicles as sensors for monitoring the traffic conditions in an urban area after a major disaster event is described. The fleet management system used for this taks is working with ral time DGPS. The system makes use of existing vehicle fleets in the urban area, rapidly collecting data and covering the whole road network. It records travel times with the help of the GPS system for every road segment driven through by each vehicle sensor, thus providing a digital time database from which traffic parameters can be also computed. It can be used for real time monitoring of traffic conditions under disaster or emergency situations where all the previously available data become invalid or unreliable. ? 2002 Wiley Periodicals, Inc.  相似文献   

Spatial‐Scene Similarity Queries     

Konstantinos A Nedas  Max J Egenhofer 《Transactions in GIS》2008,12(6):661-681

Assessing spatial scenes for similarity is difficult from a cognitive and computational perspective. Solutions to spatial‐scene similarity assessments are sensible only if corresponding elements in the compared scenes are identified correctly. This matching process becomes increasingly complex and error‐prone for large spatial scenes as it is questionable how to choose one set of associations over another or how to account quantitatively for unmatched elements. We develop a comprehensive methodology for similarity queries over spatial scenes that incorporates cognitively motivated approaches about scene comparisons, together with explicit domain knowledge about spatial objects and their relations for the relaxation of spatial query constraints. Along with a sound graph‐theoretical methodology, this approach provides the foundation for plausible reasoning about spatial‐scene similarity queries.  相似文献   

The fine and coarse particulate matter at four major Mediterranean cities: local and regional sources     

Konstantinos Dimitriou  Pavlos Kassomenos 《Theoretical and Applied Climatology》2013,114(3-4):375-391

Particulate air pollution is associated with adverse health effects to the population exposed. The aim of this paper is the identification of local and regional sources, affecting PM₁₀ and PM_2.5 levels in four large cities of southern Europe, namely: Lisbon, Madrid, Marseille, and Rome. Air pollution data from seven sampling sites of the European Union network were used. These stations were selected due to their ability of monitoring PM_2.5 concentrations and providing reliable series of data. Each station’s background was also taken into account. Pearson correlation coefficients and primal component analysis components were extracted separately for cold and warm periods in order to define the relationships among particle matters (PM_s) and gaseous pollutants (CO, NO₂, SO₂, and O₃) and evaluate the contributions of local sources. Possible seasonal variations of PM_2.5/PM₁₀ ratio daily values were also used as markers of PM sources, influencing particulate size distribution. Particle emissions were primarily attributed to traffic and secondarily to natural sources. Minimum daily values of PM_2.5/PM₁₀ ratio were observed during warm periods, particularly at suburban stations with rural background, due to dust resuspension and also due to the increase of biogenic coarse PM (pollen, dust, etc.). Hybrid Single-Particle Lagrangian Integrated Trajectory Model trajectory model was used in order to compute the 4-day backward trajectories of the air masses that affected the four cities which are under study during days with recorded PM₁₀ exceedances, within a 5-year period (2003–2007), at 300, 750, and 1,500 m above ground level (AGL). The trajectories were then divided to clusters with a K-means analysis. In all four cities, the influence of slow-moving air masses was associated with a large fraction of PM₁₀ exceedances and with high average and maximum daily mean PM₁₀ concentrations, principally at the 300 m AGL analysis. As far the issue of the increased PM₁₀ concentrations, the results were weaker in Marseille and particularly in Rome, probably due to their greater distance from Northwest Africa, in comparison to Madrid and Lisbon. Dust intrusions from the Sahara desert and transportation of Mediterranean/Atlantic sea spray, were characterized as primary regional sources of exogenous PM₁₀ in all four cities. Continental trajectories from the industrialized northern Italy affected PM₁₀ levels particularly in Marseille and Rome, due to their more eastern geographical position.  相似文献   

Assessment of freely available DSMs for automatic karst feature detection     

Maria Kakavas  Konstantinos G. Nikolakopoulos  Aggeliki Kyriou  Helen Zagana 《Arabian Journal of Geosciences》2018,11(14):388

The purpose of this work is to present the detection and qualification of natural karst depressions in southern Ksiromero, SW Aitoloakarnania Prefecture, Western Greece, by the use of freely available digital surface model (DSM) data in line with the geographical information systems—GIS. The study area is a part of the Ionian geotectonic zone whose geological background consists of the Triassic evaporates and Triassic carbonate breccias. The after-Triassic carbonate series, which consist of the Jurassic limestones, the Cretaceous limestones and the Eocene limestones, are also presented in the study area. Several DSMs such as ASTER GDEM, SRTM DEM, ALOS Global DSM, and a DSM generated from Sentinel-1 data were evaluated so as to be used for the automatic karst detection. Furthermore, a karst detection procedure applied on DSMs was performed with the aid of analogue and digital air photos. Additionally, the aforementioned procedure was applied also on DEM with the aid of digitized contours referring to topographic maps characterized by a scale of 1/50,000. All the detected features have been also validated via in situ observations. Finally, all DSMs presented herein are characterized by similar percentage of success in terms of automatic karst detection, regardless their spatial resolution and height accuracy. Their rate varies from 66 to 73%.  相似文献   

Application of the Multiple Benchmark System (MBS) to selected case study projects     

Konstantinos Anagnostopoulos  Alexandros Flamos  John Psarras 《Climate Policy》2013,13(1):45-63

Abstract

Joint Implementation (JI) and the Clean Development Mechanism (CDM) have been established under the Kyoto Protocol as project-based instruments to mitigate greenhouse gases of the industrialized countries to the levels imposed by their Kyoto commitments. An unresolved issue associated with the implementation of these two flexibility mechanisms, concerns the choice of the appropriate baseline for calculating the emission reductions in JI or CDM projects. This article describes a computerized tool that constructs and compares different types of standardized baselines and benchmarks. The analysis focuses on the suitability of several different types of benchmarks for assessing the emission reductions of certain types of projects. The analysis is also expanded into a discussion of the extent to which benchmarks reduce the crediting of non-additional projects and limit the risk of missed additional investments. This tool has been applied to actual JI and CDM projects in the Russian Federation and Indonesia.  相似文献   

Assessment of rural community and agricultural development using geomorphological–geological factors and GIS in the Trikala prefecture (Central Greece)     

George D. Bathrellos  Kalliopi Gaki-Papanastassiou  Hariklia D. Skilodimou  Georgios Aim. Skianis  Konstantinos G. Chousianitis 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(2):573-588

In this study, the potential land use planning for rural communities and agricultural development is examined with a multi-criteria analysis and Geographical Information System. For this purpose, geological, geomorphological and socio-economic data and natural hazard maps were chosen as major factors affecting both land uses. The Analytical Hierarchical Process method was applied to evaluate these factors and the uncertainty of their weight alterations estimated. Three scenarios were developed for each land use to examine the effect of uncertainty to the suitability assessment results, leading to the corresponding potential suitability maps. The areas of very high suitability are distributed mainly at the plain part of the study area. The proposed methodology comprises a case application concerning physical factors in conjunction with natural hazard maps in the land use planning procedure.  相似文献   

Geochemistry of surface sediments and heavy metal contamination assessment: Messolonghi lagoon complex,Greece   总被引：2，自引：2，他引：0  

Aristomenis P. Karageorgis  Andreas Sioulas  Evangelia Krasakopoulou  Christos L. Anagnostou  George A. Hatiris  Harikleia Kyriakidou  Konstantinos Vasilopoulos 《Environmental Earth Sciences》2012,65(6):1619-1629

The Messolonghi lagoon complex in Western Greece receives agricultural and domestic effluents both from point and diffused sources. Surface sediments were analyzed for grain size, organic carbon, total nitrogen, total sulfur, major and minor elements, aiming at the identification of geochemical relationships between all variables. Enrichment factors and the modified degree of contamination methods were applied to assess potential heavy metal enrichment related to human activities. Sediment texture was highly variable, with muddy sediments prevailing. In the central sector of the Messolonghi lagoon, organic carbon contents were high. Principal factor analysis revealed the following main groups of variables with common geochemical behavior: (1) terrigenous aluminosilicates (2) organic matter, (3) biogenic carbonates, (4) mineral quartz-aluminosilicates, and (5) Mn-oxides. Enrichment factors estimated for V, Cr, Mn, Co, Ni, Cu, Zn, and Pb using local pre-industrial sediment showed that all metals exhibit almost natural background levels, except for Pb, which was found to be slightly elevated (legacy of leaded fuel). Estimation of contamination factors concluded in similar results, whereas the overall modified degree of contamination was at the lowest level, therefore suggesting that this transitional water body has not been affected by anthropogenic activities. The data set may be considered as a baseline for future monitoring projects according to EU policy.  相似文献   

Potential suitability for urban planning and industry development using natural hazard maps and geological–geomorphological parameters     

George D. Bathrellos  Kalliopi Gaki-Papanastassiou  Hariklia D. Skilodimou  Dimitrios Papanastassiou  Konstantinos G. Chousianitis 《Environmental Earth Sciences》2012,66(2):537-548

During the planning of an urban environment, usually only economic and social parameters are taken into account. As a result, urban areas are susceptible to natural disasters, which cause extensive damages in them, because the cities or towns have been repeatedly located in vulnerable areas. In this study, for the protection of human environment, is proposed a unique approach of urban planning and sustainable development. The study area is Trikala Prefecture (Western Thessaly, Central Greece). An integrated evaluation of the suitable areas for urban growth and light industry development is proposed by using mainly natural hazards as well as geological–geomorphological–geographical characteristics of the study area. The used parameters were correlated by using the analytical hierarchical process (AHP) method and incorporated into a geographic information system (GIS) in order to produce the corresponding suitability maps. The study area is classified in five categories of very high, high, moderate, low, and very low suitability for urban growth and industrial development. Moreover, the spatio-temporal changes of the urban limits are studied since 1885 for the three major towns (Trikala, Kalambaka and Pyli) of the study area. These changes sketch out the urban growth trend. The comparison between the urban growth trend with the potential suitability for urban growth and industrial development of these towns lead to discrepancies. These can be attributed mainly to the fact that in the majority of cases, only geographical, social, and economical factors were used for urban development, whereas in our study, natural hazards, geomorphological, and geographical parameters were quantified and taken into account.  相似文献   

On the Motivation and Foundation of Natural Time Analysis: Useful Remarks     

Panayiotis A. Varotsos  Nicholas V. Sarlis  Efthimios S. Skordas 《Acta Geophysica》2016,64(4):841-852

Since its introduction in 2001, natural time analysis has been applied to diverse fields with remarkable results. Its validity has not been doubted by any publication to date. Here, we indicate that frequently asked questions on the motivation and the foundation of natural time analysis are directly answered if one takes into account the following two key points that we have considered as widely accepted when natural time analysis was proposed: first, the aspects on the energy of a system forwarded by Max Planck in his Treatise on Thermodynamics; second, the theorem on the characteristic functions of probability distributions which Gauss called Ein Schönes Theorem der Wahrscheinlichkeitsrechnung (beautiful theorem of probability calculus). The case of the time series of earthquakes and of the precursory Seismic Electric Signals are discussed as typical examples.  相似文献