Neotectonic evolution of northwestern-continental Greece     

Dr. Theodor Doutsos  Dr. Nikolaos Kontopoulos  Dr. Dimitris Frydas 《International Journal of Earth Sciences》1987,76(2):433-450

The post-Miocene sedimentary and structural evolution of NW-continental Greece changes from west to east.In the west, along the Ionian coast, the tectonic activity of the Mio-Pliocene marine sedimentation is reflected in olisthostromes and intrafoliated folds. During the emergence of the area at the Pliocene/Pleistocene boundary, low angle thrusting, dissolution cleavage and open NNW to NNE trending folds, were developed. This horizontal shortening is the result of active plate convergence between the Apulian plate and the Aegean plate. Subsequent vertical movements continuing till the precent, produces mainly NNW and ENE directed faults.In the east, between the Ionian coast and Pindus thrust, nonmarine sedimentation began, in the middle Pliocene, on a folded and partially eroded substratum. Long fault bounded intramountaneous basins formed during general uplift and extension in three directions: NNW, ENE and WNW. Extension in both areas, resulting from NNW and ENE faults, is interpreted in terms of the action of upwelling convective currents induced by the Hellenic subduction. As the Aegean back arc extension migrated slowly westwards, the whole study area was gradually affected by WNW trending grabens.

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Zusammenfassung Spätmiozäne Sedimentationsprozesse sowie strukturelle Entwicklung ändern sich in NW kontinental-Griechenland in E-W Richtung.An der Ionischen Küste wurden während der spätmiozänen Absenkung des Sedimentationsraumes mächtige Olisthostrome und intrafoliale Falten gebildet. An der Grenze des Plio/Pleistozäns wurden flache überschiebungen, Lösungsschieferung und NNW bis NNE streichende, geöffnete Falten entwickelt. Diese tektonische Strukturen sind das Ergebnis aktiver Plattenkonvergenz zwischen der apulischen lithosphären-Platte und der ägäischen Platte. Während der postorogenen Aufhebung sind NNW und ENE streichende Verwerfungen entstanden.Im mittleren Pliozän wurden im Raum zwischen Ionischem Meer und der Pindos überschiebung auf dem gefalteten und teilweise erodierten Untergrund vorwiegend limnisch-terrestrische Sedimente abgelagert. Während der postorogenen Ausweitung sind Absenkungsräume in NNW- und ENE Richtung entstanden. Sie sind vermutlich das Ergebnis von Konvektionsströmungen innerhalb der Asthenosphäre, die durch die Hellenische Subduktion hervorgerufen wurden.Die Krustenausdehnung im ägäischen »back-arc basin« hat sich kontinuierlich gegen Westen verlagert, so da\ West-Griechenland zusätzlich von WNW streichenden Grabenstrukturen weitgehend deformiert ist.

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Résumé La partie nord-occidentale de la Grèce continentale montre, d'est en ouest, une modification des processus sédimentaires et structuraux.A l'ouest, le long de la cÔte ionienne, la sédimentation marine subsidente tardi-miocène s'est accompagnée de puissants olisthostromes et de plis intrafoliaux. La limite Pliocène-Pleistocène a vu se développer des charriages peu inclinés et des plis ouverts NNE à NNW accompagnés d'une schistosité de dissolution. Ce raccourcissement horizontal est le résultat de la convergence des plaques apulienne et égéenne. Il a été suivi de mouvements subséquents verticaux, encore actifs aujourd'hui, responsables de failles de directions NNW et ENE.Plus à l'est, entre la cÔte ionienne et le charriage du Pinde, une sédimentation continentale s'est installée, au Pliocène moyen, sur le substratum plissé et partiellement érodé. Au cours du soulèvement post-orogénique, des bassins intramontagneux de grabens se sont formés selon trois directions: NNW, ENE et WNW. Les deux premières sont interprétées comme le résultat de courants de convection induits dans l'asthénosphère par la subduction hellénique. Les grabens WNW seraient en relation avec le déplacement progressif vers l'ouest de la zone d'extension crustale du bassin d'arrière-arc égéen.

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A double DNA approach for identifying Macrorhamphosus scolopax (Pisces, Centriscidae)     

Karaiskou  Nikoletta; Triantafyllidis  Alexander; Margaroni  Maritsa; Karatzas  Dimitris; Triantaphyllidis  Costas 《ICES Journal of Marine Science》2005,62(8):1683-1690

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Western Palaearctic palaeoenvironmental conditions during the Early and early Middle Pleistocene inferred from large mammal communities,and implications for hominin dispersal in Europe     

Ralf-Dietrich Kahlke  Nuria García  Dimitris S. Kostopoulos  Frédéric Lacombat  Adrian M. Lister  Paul P.A. Mazza  Nikolai Spassov  Vadim V. Titov 《Quaternary Science Reviews》2011,30(11-12):1368-1395

Large-scale fluctuations in global climate and resulting changes in ecology had a profound effect on human evolution and dispersal. Though hominin remains are scarce, studies focussing on the more abundant records of fossil land mammal communities can contribute greatly to our knowledge of the palaeoenvironmental circumstances that influenced and directed the global spread of hominins. To produce a comprehensive and accurate account of the evolution of western Palaearctic habitat diversity between 2.6 and 0.4 Ma BP, information generated from large mammal communities from 221 key sites has been included in this study.The palaeoecological conditions of the western Palaearctic during the Early and early Middle Pleistocene were principally controlled by the following key factors: (1) a widespread trend of temperature decrease, (2) the periodicity of the global temperature record, (3) the intensity of single climatic stages, (4) the temporal pattern of climatic variation, (5) geographical position, and (6) the distribution of continental water resources. A general picture of the evolution of western Palaearctic habitat diversity saw the replacement of extensive forested terrain by an alternating sequence of varied savannah-like and forested habitats during the 2.6–1.8 Ma span, as well as an alternation between different types of predominantly open habitats between 1.8 and 1.2 Ma. Both of these processes were governed by 41 ka temperature periodicity. During the 1.2–0.9 Ma time span, irregular climatic fluctuations were more common and habitat variability increased. The subsequent 0.9–0.4 Ma interval, a period controlled by 100 ka periodicity, was by comparison more stable, with longer climatic cycles alternating between open and forested landscapes. During the entire Early and early Middle Pleistocene, assemblages of large mammal communities reveal a distinct trend of decreasing continentality between Eastern and South-Eastern Europe on the one hand, and South-Western and North-Western Europe on the other. This trend was due to the effect of the Atlantic Ocean, while in Southern Europe the relatively low continentality was balanced by influences from the Mediterranean Sea.When plotted against evidence of hominin occurrence, the data on western Palaearctic habitat diversity inferred from large mammal communities indicate clear environmental stimuli for the earliest human dispersal in Europe. These are: (1) a wide range of habitats, implying a high diversity of resources; (2) mild climates with low seasonality, implying a lack of strong environmental fluctuations. Around 1.8 Ma at the latest, hominins of African origin entered the western Palaearctic for the first time, taking advantage of the diversity of habitats and resources, particularly along large river systems. Their subsequent westward spread between 1.7 and 1.3 Ma was restricted to Mediterranean-influenced areas, which offered a high variability of habitats and relatively low seasonality. The increase in environmental diversity, which occurred from 1.2 Ma onwards, opened up South-Eastern and Eastern Europe for hominin occupation. According to the available records, North-Western and Central Europe were initially colonized during late Early to early Middle Pleistocene interglacials, when these regions experienced periods of low seasonality and considerable habitat diversity.  相似文献   

Soil–foundation–structure interaction and vulnerability assessment of the Neoclassical School in Rhodes,Greece     

Anna Karatzetzou  Dimitris Pitilakis  Meta Kržan  Vlatko Bosiljkov 《Bulletin of Earthquake Engineering》2015,13(1):411-428

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Use of rubberised backfills for improving the seismic response of integral abutment bridges     

Sotiris Argyroudis  Anastasia Palaiochorinou  Stergios Mitoulis  Dimitris Pitilakis 《Bulletin of Earthquake Engineering》2016,14(12):3573-3590

Reuse of the 1.5 billion waste tyres that are produced annually is a one of the major worldwide challenges, as waste tyres are toxic and cause pollution to the environment. In recognition of this problem, this paper introduces the reuse of tyres, in the form of derived aggregates in mixtures with granulated soil materials, as previous studies indicated the potential benefits of these materials in the seismic performance of structures. The objective of the present research study is to investigate whether use of rubberised backfills benefits the seismic response of Integral Abutment Bridges (IABs) by enhancing soil-structure interaction (SSI) effects. Numerical models including typical integral abutments on surface foundation with nonlinear conventional backfill material and its alternative form as soil-rubber mixtures are analysed and their response parameters are compared. The research is conducted on the basis of parametric analysis, which aims to evaluate the influence of different rubber-soil mixtures on the dynamic response of the abutment-backfill system under various seismic excitations, accounting for dynamic soil-abutment interaction. The results provide evidence that the use of rubberised backfill leads to reductions in the backfill settlements, the horizontal displacements of the bridge deck, the residual horizontal displacements of the top of the abutment and the pressures acting on the abutment, up to 55, 18, 43 and 47 % respectively, with respect to a conventional backfill comprising of clean sand. Small change in bending moments and shear forces on the abutment wall is also observed. Therefore, rubberised backfills offer promising solution to mitigate the earthquake risk, towards economic design with minimal damage objectives for the resilience of transportation networks.  相似文献   

Inclusion of P–Δ effect in displacement‐based seismic design of steel moment resisting frames     

Aristidis V. Asimakopoulos  Dimitris L. Karabalis  Dimitri E. Beskos 《地震工程与结构动力学》2007,36(14):2171-2188

A procedure for treating the P– Δ effect in the direct displacement‐based seismic design of regular steel moment resisting frames with ideal elastoplastic material behaviour is proposed. A simple formula for the yield displacement amplification factor as a function of ductility and the stability coefficient is derived on the basis of the seismic response of an inelastic single degree‐of‐freedom system taking into account the P– Δ effect. Extensive parametric seismic inelastic analyses of plane moment resisting steel frames result in a simple formula for the dynamic stability coefficient as a function of the number of stories of a frame and the column to beam stiffness ratio. Thus, the P– Δ effect can be easily taken into account in a direct displacement‐based seismic design through the stability coefficient and the yield displacement amplification factor. A simple design example serves to illustrate the application of the proposed method and demonstrate its merits. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Location Performance and Detection Threshold of the Spanish National Seismic Network     

Antonino D’Alessandro  José Badal  Giuseppe D’Anna  Dimitris Papanastassiou  Ioannis Baskoutas  Nurcan M. Özel 《Pure and Applied Geophysics》2013,170(11):1859-1880

Spain is a low-to-moderate seismicity area with relatively low seismic hazard. However, several strong shallow earthquakes have shaken the country causing casualties and extensive damage. Regional seismicity is monitored and surveyed by means of the Spanish National Seismic Network, maintenance and control of which are entrusted to the Instituto Geográfico Nacional. This array currently comprises 120 seismic stations distributed throughout Spanish territory (mainland and islands). Basically, we are interested in checking the noise conditions, reliability, and seismic detection capability of the Spanish network by analyzing the background noise level affecting the array stations, errors in hypocentral location, and detection threshold, which provides knowledge about network performance. It also enables testing of the suitability of the velocity model used in the routine process of earthquake location. To perform this study we use a method that relies on P and S wave travel times, which are computed by simulation of seismic rays from virtual seismic sources placed at the nodes of a regular grid covering the study area. Given the characteristics of the seismicity of Spain, we drew maps for M _L magnitudes 2.0, 2.5, and 3.0, at a focal depth of 10 km and a confidence level 95 %. The results relate to the number of stations involved in the hypocentral location process, how these stations are distributed spatially, and the uncertainties of focal data (errors in origin time, longitude, latitude, and depth). To assess the extent to which principal seismogenic areas are well monitored by the network, we estimated the average error in the location of a seismic source from the semiaxes of the ellipsoid of confidence by calculating the radius of the equivalent sphere. Finally, the detection threshold was determined as the magnitude of the smallest seismic event detected at least by four stations. The northwest of the peninsula, the Pyrenees, especially the westernmost segment, the Betic Cordillera, and Tenerife Island are the best-monitored zones. Origin time and focal depth are data that are far from being constrained by regional events. The two Iberian areas with moderate seismicity and the highest seismic hazard, the Pyrenees and Betic Cordillera, and the northwestern quadrant of the peninsula, are the areas wherein the focus of an earthquake is determined with an approximate error of 3 km. For M _L 2.5 and M _L 3.0 this error is common for almost the whole peninsula and the Canary Islands. In general, errors in epicenter latitude and longitude are small for near-surface earthquakes, increasing gradually as the depth increases, but remaining close to 5 km even at a depth of 60 km. The hypocentral depth seems to be well constrained to a depth of 40 km beneath the zones with the highest density of stations, with an error of less than 5 km. The M _L magnitude detection threshold of the network is approximately 2.0 for most of Spain and still less, almost 1.0, for the western sector of the Pyrenean region and the Canary Islands.  相似文献   

Adriatic ‘opisthobranchs’ (Gastropoda,Heterobranchia): shedding light on biodiversity issues          下载免费PDF全文

Argyro Zenetos  Vesna Mačić  Andrej Jaklin  Lovrenc Lipej  Dimitris Poursanidis  Riccardo Cattaneo‐Vietti  Sajmir Beqiraj  Federico Betti  Diego Poloniato  Lefter Kashta  Stelios Katsanevakis  Fabio Crocetta 《Marine Ecology》2016,37(6):1239-1255

We herein review the Adriatic opisthobranch fauna, provide an updated checklist of 223 species and assess their distribution at regional and country levels. New Adriatic records are provided for 67 opisthobranch taxa, adding three new records for the Italian coastline, five new records for Albania, eight for Croatia and 15 for Montenegro. The presence of Hermaea bifida (Montagu, 1815), Hermaea variopicta (Costa A., 1869) and Facelina annulicornis (Chamisso & Eysenhardt, 1821) is reported for the first time from anywhere in the Adriatic Sea. Including the new findings, our inventory includes 28 species from Albania, 163 from Croatia, 178 from the Italian coastline of the Adriatic, 41 from Montenegro and 74 from Slovenia. No records were available from Bosnia and Hercegovina. Ninety species (40.4%) are widespread, and were recorded from all three main divisions (Northern, Western and Eastern Adriatic), whilst 79 species (35.4%) were reported from only one of them. At sub‐division levels, the Albanian inventory is the most dissimilar to the other country/regional lists, presumably because of the lack of targeted field surveys. The highest similarity is observed amongst the Western Adriatic, Croatia and the Italian Ionian coastline. Seven alien, one possible alien and three cryptogenic opisthobranchs were reliably recorded from the Adriatic Sea. The first Mediterranean records of five species were in the Adriatic Sea, of which four species have not been found elsewhere in the Mediterranean. Shipping and aquaculture are the probable pathways for most of the alien species. A steady rate of one to two alien introductions per decade since the 1970s was evident. The Northern Adriatic coasts are the most affected by alien invasions, probably due to repeated local introductions along with shellfish transfers (oysters, mussels, Manila clams), and heavy maritime transport.  相似文献   

The volcanic debris avalanche on the SE submarine slope of Nisyros volcano, Greece: geophysical exploration and implications for subaerial eruption history     

Isidoros Livanos  Paraskevi Nomikou  Dimitris Papanikolaou  Grigoris Rousakis 《Geo-Marine Letters》2013,33(6):419-431

A spectacular hummocky topography was discovered offshore of the south-eastern slope of the Nisyros island volcano in the eastern sector of the Aegean volcanic arc in 2000–2001, using multibeam bathymetric mapping and seismic profiling, and interpreted as part of a volcanic debris avalanche originating onland. During E/V Nautilus cruise NA011 in 2010, a detailed side-scan sonar and ROV exploration aimed at evaluating the surface morphology of this avalanche field. Combining the new data with selected older datasets reveals that the debris avalanche is characterized by numerous (at least 78) variously sized and shaped hummocks. Some of these are distinctly round, either scattered or aligned in groups, whereas others are elongated in the form of ridges. This is consistent with existing models accounting for variations in the longitudinal and lateral velocity ratio of landslides. Maximum dimensions reach 60 m in height above the sea bottom, 220 m in length and 230 m in width. The structures outline a large tongue-shaped, submarine hummock field of about 22.2 km², approx. 4.8 km wide and 4.6 km long and with an estimated volume of 0.277 km³. Due to its characteristic shape, the collapsed volcanic flank is interpreted to represent a singular failing event, involving a rapid and virtually instantaneous downslope movement of the slide mass into the sea. Indeed, the H/L (height of 280 m vs. run-out of 7 km) ratio for the Nisyros slide is 0.04; plotted against volume, this falls within the theoretical bounds as well as measured values typical of submarine landslides. The timing of the event is probably related to the extrusion of Nikia lavas and their subsequent failure and formation of a main scarp observed at about 120 m depth on an 8-km-long seismic profile and a map of slope angle distribution, at the depth where the palaeo-coastline was located 40 ka ago. An inferred age of ca. 40 ka for the avalanche awaits confirmation based on dating of core material.  相似文献   

Ca(OH)2 Pre‐Treated Bentonite for Phosphorus Removal and Recovery From Synthetic and Real Wastewater          下载免费PDF全文

Giorgos Markou  Dimitris Mitrogiannis  Vassilis Inglezakis  Koenraad Muylaert  Nikolaos Koukouzas  Nikolaos Tsoukalas  Efstratios Kamitsos  Dimitrios Palles  Ioannis Baziotis 《洁净——土壤、空气、水》2018,46(2)

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