Sample records for corinth rift greece

  1. Ambient noise tomography of the western Corinth Rift, Greece (United States)

    Giannopoulos, Dimitrios; Rivet, Diane; Sokos, Efthimios; Deschamps, Anne; Mordret, Aurelien; Lyon-Caen, Hélène; Bernard, Pascal; Paraskevopoulos, Paraskevas; Tselentis, G.-Akis


    Three years of continuous waveform data recorded at 22 stations from the Corinth Rift Laboratory and the Hellenic Unified Seismological Network are used to perform an ambient noise surface wave tomography of the western Corinth Rift. All available vertical component time-series were cross-correlated to extract empirical Rayleigh-wave Green's functions. Group velocity dispersion curves were measured for each station-pair by applying frequency-time analysis and then inverted to build 2-D group velocity maps between 1 and 6 s period. Finally, we locally inverted these velocity maps using a neighbourhood algorithm to assess the 3-D shear-velocity model of the shallow crustal structure of the western Corinth Rift. Across all studied periods the southern coast of the Corinth Gulf is generally imaged as a region of lower velocities compared to the northern coast. At periods up to 3 s, the spatial variation of the group velocities is correlated with the surface geology of the area. Lower velocities are observed in areas where mostly Plio-Quaternary syn-rift sediments are present, such as offshore regions of the rift, the Mornos delta and the largest part of the southern coast. Higher velocities are observed in pre-rift basement structures which are dominated mostly by carbonates. At periods above 3 s, where Rayleigh-waves begin to sense deeper structures below the sediments within the underlying basement, our study highlights the presence of a distinct zone of lower velocities across the southern part of the rift with an elongation in the WNW-ESE direction. The interpretation of this low velocity includes two arguments, the present-day active tectonic regime and the possible involvement of fluids circulation processes at depth within a highly fractured upper crust in the vicinity of the major faults zones. In general, the results demonstrate good agreement with the major geological and tectonic features of the area, as well as with previous local earthquake tomography

  2. Antecedent rivers and early rifting: a case study from the Plio-Pleistocene Corinth rift, Greece (United States)

    Hemelsdaël, Romain; Ford, Mary; Malartre, Fabrice


    Models of early rifting present syn-rift sedimentation as the direct response to the development of normal fault systems where footwall-derived drainage supplies alluvial to lacustrine sediments into hangingwall depocentres. These models often include antecedent rivers, diverted into active depocentres and with little impact on facies distributions. However, antecedent rivers can supply a high volume of sediment from the onset of rifting. What are the interactions between major antecedent rivers and a growing normal fault system? What are the implications for alluvial stratigraphy and facies distributions in early rifts? These questions are investigated by studying a Plio-Pleistocene fluvial succession on the southern margin of the Corinth rift (Greece). In the northern Peloponnese, early syn-rift deposits are preserved in a series of uplifted E-W normal fault blocks (10-15 km long, 3-7 km wide). Detailed sedimentary logging and high resolution mapping of the syn-rift succession (400 to 1300 m thick) define the architecture of the early rift alluvial system. Magnetostratigraphy and biostratigraphic markers are used to date and correlate the fluvial succession within and between fault blocks. The age of the succession is between 4.0 and 1.8 Ma. We present a new tectonostratigraphic model for early rift basins based on our reconstructions. The early rift depositional system was established across a series of narrow normal fault blocks. Palaeocurrent data show that the alluvial basin was supplied by one major sediment entry point. A low sinuosity braided river system flowed over 15 to 30 km to the NE. Facies evolved downstream from coarse conglomerates to fined-grained fluvial deposits. Other minor sediment entry points supply linked and isolated depocentres. The main river system terminated eastward where it built stacked small deltas into a shallow lake (5 to 15 m deep) that occupied the central Corinth rift. The main fluvial axis remained constant and controlled

  3. The Corinth Rift Laboratory, Greece (CRL) : A Multidisciplinary Near Fault Observatory (NFO) on a Fast Rifting System (United States)

    Bernard, P.; Lyon-Caen, H.; Deschamps, A.; Briole, P.; Lambotte, S.; Ford, M.; Scotti, O.; Beck, C.; Hubert-Ferrari, A.; Boiselet, A.; Godano, M.; Matrullo, E.; Meyer, N.; Albini, P.; Elias, P.; Nercessian, A.; Katsonopoulou, D.; Papadimitriou, P.; Voulgaris, N.; Kapetanidis, V.; Sokos, E.; Serpetsidaki, A.; el Arem, S.; Dublanchet, P.; Duverger, C.; Makropoulos, K.; Tselentis, A.


    The western rift of Corinth (Greece) is one of the most active tectonic structures of the euro-mediterranean area. Its NS opening rate is 1.5 cm/yr ( strain rate of 10-6/yr) results into a high microseismicity level and a few destructive, M>6 earthquakes per century, activating a system of mostly north dipping normal faults. Since 2001, monitoring arrays of the European Corinth Rift Laboratory (CRL, allowed to better track the mechanical processes at work, with short period and broad band seismometers, cGPS, borehole strainmeters, EM stations, …). The recent (300 kyr) tectonic history has been revealed by onland (uplifted fan deltas and terraces) and offshore geological studies (mapping, shallow seismic, coring), showing a fast evolution of the normal fault system. The microseismicity, dominated by swarms lasting from days to months, mostly clusters in a layer 1 to 3 km thick, between 6 and 9 km in depth, dipping towards north, on which most faults are rooting. The diffusion of the microseismicity suggests its triggering by pore pressure transients, with no or barely detected strain. Despite a large proportion of multiplets, true repeaters seem seldom, suggesting a minor contribution of creep in their triggering, although transient or steady creep is clearly detected on the shallow part of some majors faults. The microseismic layer may thus be an immature, downward growing detachment, and the dominant rifting mechanism might be a mode I, anelastic strain beneath the rift axis , for which a mechanical model is under development. Paleoseismological (trenching, paleoshorelines, turbidites), archeological and historical studies completed the catalogues of instrumental seismicity, motivating attempts of time dependent hazard assessment. The Near Fault Observatory of CRL is thus a multidisciplinary research infrastructure aiming at a better understanding and modeling of multiscale, coupled seismic/aseismic processes on fault systems.

  4. Methodology for earthquake rupture rate estimates of fault networks: example for the western Corinth rift, Greece (United States)

    Chartier, Thomas; Scotti, Oona; Lyon-Caen, Hélène; Boiselet, Aurélien


    Modeling the seismic potential of active faults is a fundamental step of probabilistic seismic hazard assessment (PSHA). An accurate estimation of the rate of earthquakes on the faults is necessary in order to obtain the probability of exceedance of a given ground motion. Most PSHA studies consider faults as independent structures and neglect the possibility of multiple faults or fault segments rupturing simultaneously (fault-to-fault, FtF, ruptures). The Uniform California Earthquake Rupture Forecast version 3 (UCERF-3) model takes into account this possibility by considering a system-level approach rather than an individual-fault-level approach using the geological, seismological and geodetical information to invert the earthquake rates. In many places of the world seismological and geodetical information along fault networks is often not well constrained. There is therefore a need to propose a methodology relying on geological information alone to compute earthquake rates of the faults in the network. In the proposed methodology, a simple distance criteria is used to define FtF ruptures and consider single faults or FtF ruptures as an aleatory uncertainty, similarly to UCERF-3. Rates of earthquakes on faults are then computed following two constraints: the magnitude frequency distribution (MFD) of earthquakes in the fault system as a whole must follow an a priori chosen shape and the rate of earthquakes on each fault is determined by the specific slip rate of each segment depending on the possible FtF ruptures. The modeled earthquake rates are then compared to the available independent data (geodetical, seismological and paleoseismological data) in order to weight different hypothesis explored in a logic tree.The methodology is tested on the western Corinth rift (WCR), Greece, where recent advancements have been made in the understanding of the geological slip rates of the complex network of normal faults which are accommodating the ˜ 15 mm yr-1 north

  5. Straight from the source's mouth; a quantitative study of grain-size export for an entire active rift, the Corinth Rift, central Greece (United States)

    Watkins, Stephen E.; Whittaker, Alexander C.; Bell, Rebecca E.; Brooke, Sam A. S.; McNeill, Lisa C.; Gawthorpe, Robert L.


    The volumes, grain sizes and characteristics of sediment supplied from source catchments fundamentally controls basin stratigraphy. However, to date, few studies have constrained sediment budgets, including grain size, released into an active rift basin at a regional scale. The Gulf of Corinth, central Greece, is one of the most rapidly extending rifts in the world, with geodetic measurements of 5 mm/yr in the East to 15 mm/yr in the West. It has well-constrained climatic and tectonic boundary conditions and bedrock lithologies are well-characterised. It is therefore an ideal natural laboratory to study the grain-size export for a rift. In the field, we visited the river mouths of 49 catchments draining into the Corinth Gulf, which in total drain 83% of the rift. At each site, hydraulic geometries, surface grain-size of channel bars and full-weighted grain-size distributions of river sediment were obtained. The surface grain-size was measured using the Wolman point count method and the full-weighted grain-size distribution of the bedload by in-situ sieving. In total, approximately 17,000 point counts and 3 tonnes of sediment were processed. The grain-size distributions show an overall increase from East to West on the southern coast of the gulf, with largest grain-sizes exported from the Western rift catchments. D84 ranges from 20 to 110 mm, however 50% of D84 grain-sizes are less than 40 mm. Subsequently, we derived the full Holocene sediment budget for the Corinth Gulf by combining our grain size data with catchment sediment fluxes, constrained using the BQART model and calibrated to known Holocene sediment volumes in the basin from seismic data (c.f. Watkins et al., in review). This is the first time such a budget has been derived for the Corinth Rift. Finally, our estimates of sediment budgets and grain sizes were compared to regional uplift constraints, fault distributions, slip rates and lithology to identify the relative importance of these controls on

  6. Anomalous stress diffusion, Omori's law and Continuous Time Random Walk in the 2010 Efpalion aftershock sequence (Corinth rift, Greece) (United States)

    Michas, Georgios; Vallianatos, Filippos; Karakostas, Vassilios; Papadimitriou, Eleftheria; Sammonds, Peter


    rift (Greece). Nonlin. Processes Geophys., 20, 713-724. Sokos, E., Zahradník, J., Kiratzi, A., Janský, J., Gallovič, F., Novotny, O., Kostelecký, J., Serpetsidaki, A., Tselentis, G.-A. (2012). The January 2010 Efpalio earthquake sequence in the western Corinth gulf (Greece). Tectonophysics, 530-531, 299-309. Utsu, T., Y. Ogata, Matsu'ura R. S. (1995). The centenary of the Omori formula for a decay law of aftershock activity. J. Phys. Earth, 43, 1- 33.

  7. Physics-based and statistical earthquake forecasting in a continental rift zone: the case study of Corinth Gulf (Greece) (United States)

    Segou, Margarita


    I perform a retrospective forecast experiment in the most rapid extensive continental rift worldwide, the western Corinth Gulf (wCG, Greece), aiming to predict shallow seismicity (depth evaluate the forecasts for six months following the 1995 M = 6.4 Aigio earthquake using log-likelihood performance metrics. For the ETAS realizations, I use seismic events with magnitude M ≥ 2.5 within daily update intervals to enhance their predictive power. For assessing the role of background seismicity, I implement a stochastic reconstruction (aka declustering) aiming to answer whether M > 4.5 earthquakes correspond to spontaneous events and identify, if possible, different triggering characteristics between aftershock sequences and swarm-type seismicity periods. I find that: (1) ETAS models outperform CRS models in most time intervals achieving very low rejection ratio RN = 6 per cent, when I test their efficiency to forecast the total number of events inside the study area, (2) the best rejection ratio for CRS models reaches RN = 17 per cent, when I use varying target depths and receiver plane geometry, (3) 75 per cent of the 1995 Aigio aftershocks that occurred within the first month can be explained by static stress changes, (4) highly variable performance on behalf of both statistical and physical models is suggested by large confidence intervals of information gain per earthquake and (5) generic ETAS models can adequately predict the temporal evolution of seismicity during swarms. Furthermore, stochastic reconstruction of seismicity makes possible the identification of different triggering processes between specific seismic crises (2001, 2003-04, 2006-07) and the 1995 aftershock sequence. I find that: (1) seismic events with M ≥ 5.0 are not a part of a preceding earthquake cascade, since they are characterized by high probability being a background event (average Pback > 0.8) and (2) triggered seismicity within swarms is characterized by lower event productivity when

  8. Ground deformation and associated risk in the Gulf of Corinth (Greece) (United States)

    Del Soldato, Matteo; Raspini, Federico; Del Ventisette, Chiara; Righini, Gaia; Moretti, Sandro


    The potential of repeat-pass satellite SAR (Synthetic Aperture Radar) interferometry has been exploited to detect, map and characterize ground deformations in the western part of the Gulf of Corinth (Greece). The Gulf of Corinth separates the Peloponnesus from the continental Greece and the northern coast area of the Peloponnese peninsula is identified as one of the most rapidly developed intercontinental rift in the Mediterranean region. Active deformations affect the whole study area caused by faults, sub-aerial and sub-marine earthquakes inducing landslides, changing drainage patterns and seismic activity, both historical and recent. ERS and Envisat dataset, covering the period from 1992 to 2008 have been analyzed at both local and wide scale, with the support of thematic maps (i.e. topographic, geomorphologic, geological and land use maps), high-resolution optical images (both aerial and satellite data) and in situ data. The combination of all data allowed to investigate wide urbanized and vegetated areas for the investigation of geological processes to obtain an accurate analysis of the phenomena (i.e. typology, spatial extension, causes and its temporal evolution). A landslide inventory map has been compiled for the study area, integrating, at the scale of single slope, satellite-based ground deformation measurements with geomorphological analysis of landforms, that is, coupling a new remote sensing technique with a conventional approach. Mapped landslides have been classified according to their type and state of activity. Furthermore, interferometric results have been analyzed at a basin scale as support for land subsidence mapping and for investigating of aseismic deformations of active faults.

  9. Basement depth and sedimentary infill from deep seismic reflection data at the western tip of the offshore Corinth Rift (United States)

    Beckers, Arnaud; Tripsanas, Efthymios; Hubert-Ferrari, Aurélia; Beck, Christian; Sakellariou, Dimitris


    The Corinth rift is a young continental rift located in central Greece. The active part of the rift forms an E-W striking depression - the Gulf of Corinth - that is the deepest in its central part. Extensive seismic surveys have imaged the basin's basement and allowed to estimate the total extension across most of the Gulf except its western tip. Extension is high in the central part and decreases westward and eastward, as reflected in the present-day bathymetry. Two decades of GPS measurements have shown that the extension rate increases westwards from ~5 to 10-15 mm yr-1, but this is not consistent with the long term pattern. However, no data allowed so far to estimate the basement depth at the western tip of the Gulf, where the geodetic extension rate is the largest. Such data would allow to check the apparent inconsistency between the present rate and the long-term estimates of crustal extension. We present here an unpublished multichannel seismic line dating from 1979 and crossing the western tip of the Gulf of Corinth. The line is 22 km long and strikes WNW-ESE, from the Mornos delta to the West-Channel fault. A Maxipulse source has been used, allowing to image the basement below the synrift sedimentary infill. To the east, a ~1.6 km deep basin is imaged between the southern margin of the Gulf and an inactive south-dipping fault located between the Aigion and the Trizonia faults. The sedimentary infill consists in an alternation between basin-focused bodies made of incoherent reflections and more extensive high-amplitude reflectors. Attributing this alternation to eustatic variations give an age of 300-350 ka to the oldest well imaged deposits. Northwest of the Trizonia fault, the basement is imaged at shallower depth, i.e. ~450 m. The western tip of the seismic line reaches the Mornos delta, close to the northern shoreline. There, the depth to the basement is larger, reaching ~1.2 km. The infill is made of 3 units : on the basement lies a thin unit of

  10. Crustal structure of the Gulf of Corinth in Central Greece, determined from magnetotelluric soundings

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    G. N. Stavrakakis


    Full Text Available The magnetotelluric sounding method at 15 sites was employed to investigate the electrical properties of the crust and upper mantle near the epicentral region of the June 15 1995, Ms = 6.1, destructive earthquake in the Gulf of Corinth, Central Greece. The magnetotelluric results indicate the presence of a conductive zone in the mid-crust at a depth of 9 to 12 km near the seismogenetic region. The existence of this zone with a thickness of around 7 km can be explained by the presence of fluids in a zone of ductile shear. A second electrical discontinuity was also found at a depth of about 28 km and this may well correspond to the Moho below the Gulf of Corinth.

  11. Temporal pattern in Corinth rift seismicity revealed by visibility graph analysis (United States)

    Hloupis, George


    The investigation of complex time series properties through graph theoretical tools was greatly benefited from the recently developed method of visibility graph (VG) which acts as a hub between nonlinear dynamics, graph theory and time series analysis. In this work, earthquake time series, a representative example of a complex system, was studied by using VG method. The examined time series extracted from the Corinth rift seismic catalogue. By using a sliding window approach the temporal evolution of exponent γ of the degree distribution was studied. It was found that the time period of the most significant event (seismic swarm after major earthquake) in the examined seismic catalogue coincides with the time period where the exponent γ presents its minimum.

  12. A restricted Linked Stress Release Model (LSRM) for the Corinth gulf (Greece) (United States)

    Mangira, Ourania; Console, Rodolfo; Papadimitriou, Eleftheria; Vasiliadis, Georgios


    The earthquake occurrence in the Corinth Gulf (Greece) is modeled by means of the Linked Stress Release Model, which combines the gradual increase of the strain energy due to continuous tectonic loading and its sudden release when an event occurs. The modeling is based on the theory of stochastic point processes and it is determined by the conditional intensity function. The modeled time-dependent seismicity incorporates stress transfer and interactions among the major fault segments that belong either to the western or to the eastern part of the study area. Static stress changes caused by the coseismic slip of eight characteristic events that occurred during the instrumental era were calculated. Their perturbations reveal that earthquakes occurring in the eastern part provoke excitation in the western part while the events that occurred in the western part do not affect the seismicity of the eastern part. This result was taken into account and the values of the model parameters were constrained accordingly. The analysis is also performed on synthetic earthquake catalogs developed by an earthquake simulator algorithm that can replicate the seismic activity in the study area and yields to comparable results.

  13. Fault-based Earthquake Rupture Forecasts for Western Gulf of Corinth, Greece (United States)

    Ganas, A.; Parsons, T.; Segkou, M.


    The western Gulf of Corinth has not experienced a strong earthquake since 1995 (the Ms=6.2 event of Aigion on 15 June 1995; Bernard et al., 1997), although the Gulf is extending fast (over 12 mm/yr of N-S extension from continuous GPS data spanning a period of 9+ years) and its seismic history since 1769 exhibits twelve (12) shallow events with M>6.0. We undertook an analysis of rupture forecasts along the active faults in this area of central Greece, using most updated datasets (active fault maps, fault geometry, fault slip rates, trenching data on past earthquakes, historical and instrumental seismicity, strain) and models for earthquake budget extrapolated from observed seismicity, magnitude-frequency distributions and calculated earthquake rates vs. magnitude for individual faults. We present a unified rupture forecast model that comprises a time-independent (Poisson-process) earthquake rate model, and a time-dependent earthquake-probability model, based on recent earthquake rates and stress-renewal statistics conditioned on the date of last event. The resulting rupture rate maps may be used to update building codes and promote mitigation efforts.

  14. Landscape Response to Active Extensional Faulting and Multiple Local Base Levels: The Perachora Peninsula, Eastern Gulf of Corinth, Greece (United States)

    Bujanowski-Duffy, O.; Brocklehurst, S. H.; Gawthorpe, R. L.; Finch, E.


    We integrate digital topographic analysis, remote sensing and field observations of an active extensional terrain in the Eastern Gulf of Corinth, to elucidate the controls upon spatial and temporal variations in transient landscape evolution. The ~130 km2 Perachora Peninsula is characterised by a suite of E-W trending, mainly northward-dipping normal faults. Interplay between onshore and offshore normal faulting, ongoing regional uplift and eustasy has resulted in a series of reconfigured and diverted drainage networks, with sediment dispersal patterns characterised by trapped endorheic lakes. Quantitative fluvial profile analysis was performed on a 20 m ground-truthed SPOT DEM, with the longitudinal profiles of over 100 ephemeral bedrock streams extracted. Profiles were analysed to determine the size, elevation and distribution of significant long profile convexities (knickpoints) and to develop a map of normalised channel steepness. In addition, field mapping of faults, gorges, wind-gaps, abandoned landscapes, alluvial fans, drainage reversals and drainage capture was conducted to provide details on geomorphic variability across the area and to delimit non-equilibrated portions of the landscape. Using this evidence, along with observations from the planform drainage network, we classify a series of distinct geomorphic domains and deconvolve the key controls and processes which have resulted in such variability in landscape form. The rich variability of controls across the area allows us to determine: i) the role of multiple base levels in controlling landscape evolution and sediment dispersal; ii) active processes in structural relay zones; and iii) insights into the sequence of tectonic events. Our results emphasise how the ongoing evolution of an extensional fault terrain over time-scales of hundreds of thousands of years results in a complex drainage system modified by abandoned landscapes, internal drainage, and steep knickzones. In addition, we demonstrate

  15. Observation and modeling of the seismic seiches triggered in the Gulf of Corinth (Greece) by the 2011 Mw 9.0 Tohoku earthquake (United States)

    Canitano, Alexandre; Bernard, Pascal; Allgeyer, Sébastien


    The study reports an unusual water level rise in the Gulf of Corinth, central Greece, during the passing of the seismic waves of the remote 2011 Mw 9.0 Tohoku earthquake. The seismic seiches were recorded by a tide-gauge located in the marina of the island of Trizonia, in the western side of the gulf. The cross-analysis between the ground motion and the water level changes shows that seiching was initiated by the arrival of the earlier S-waves and then enhanced by the surface waves. The seiching concerns five domains with periods ranging from minute to about 7 min and with water level changes of a few millimeters to a few centimeters. The main seiching period is about 5-7 min and the related water level has a maximum trough-to-peak amplitude of about 6-8 cm. Numerical simulation of the seismic seiches, based on the shallow water equations, allows us to model reasonably well the amplitude of the seiches for most of the period domains, excepted those for the main seiching period at 7 min, which are underestimated by a factor of about 2-3. The largest bathymetric structures of the gulf to be excited in a seiche mode, with eigenperiods of hundreds of seconds, are a few kilometers in size.

  16. Upper crust seismic anisotropy study and temporal variations of shear-wave splitting parameters in the western Gulf of Corinth (Greece) during 2013 (United States)

    Kaviris, George; Spingos, Ioannis; Kapetanidis, Vasileios; Papadimitriou, Panayotis; Voulgaris, Nicholas; Makropoulos, Kostas


    During 2013, the Western Gulf of Corinth (WGoC, Central Greece) experienced a period of increased seismicity, with a total of over 4700 earthquakes. This fact in combination with the existence of dense seismological networks provided an excellent opportunity for the study of crustal seismic anisotropy. Of special note is the seismic crisis period of May-October, during which the main feature was the occurrence of the Helike seismic swarm. Polarigrams and hodograms were employed to analyze local waveforms. This method resulted in 659 measurements of shear-wave splitting parameters, namely the direction of the fast shear-wave (Sfast), the time-delay (Td) between the two split shear-waves and the source polarization direction. A pattern of a general WNW-ESE anisotropy direction, parallel to the GoC's fault systems' strike, is established, with the exception of two stations located in adjacent areas at the north. This is in agreement with the existence of fluid-filled microcracks, oriented according to the regional stress field. The obtained splitting parameters are compared to the results of other anisotropy studies performed in the WGoC. A detailed analysis of the temporal evolution of the normalized time-delay (Tn) was performed to associate temporal stress changes to seismicity fluctuations. Increase in normalized time-delays and drop before the occurrence of the first significant event belonging to the ;July Cluster;, which occurred between the 13th and the 16th of the same month, was observed for most of the analyzed stations.

  17. A Robust Design Capture-Recapture Analysis of Abundance, Survival and Temporary Emigration of Three Odontocete Species in the Gulf of Corinth, Greece.

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    Nina Luisa Santostasi

    Full Text Available While the Mediterranean Sea has been designated as a Global Biodiversity Hotspot, assessments of cetacean population abundance are lacking for large portions of the region, particularly in the southern and eastern basins. The challenges and costs of obtaining the necessary data often result in absent or poor abundance information. We applied capture-recapture models to estimate abundance, survival and temporary emigration of odontocete populations within a 2,400 km2 semi-enclosed Mediterranean bay, the Gulf of Corinth. Boat surveys were conducted in 2011-2015 to collect photo-identification data on striped dolphins Stenella coeruleoalba, short-beaked common dolphins Delphinus delphis (always found together with striped dolphins in mixed groups and common bottlenose dolphins Tursiops truncatus, totaling 1,873 h of tracking. After grading images for quality and marking distinctiveness, 23,995 high-quality photos were included in a striped and common dolphin catalog, and 2,472 in a bottlenose dolphin catalog. The proportions of striped and common dolphins were calculated from the photographic sample and used to scale capture-recapture estimates. Best-fitting robust design capture-recapture models denoted no temporary emigration between years for striped and common dolphins, and random temporary emigration for bottlenose dolphins, suggesting different residency patterns in agreement with previous studies. Average estimated abundance over the five years was 1,331 (95% CI 1,122-1,578 striped dolphins, 22 (16-32 common dolphins, 55 (36-84 "intermediate" animals (potential striped x common dolphin hybrids and 38 (32-46 bottlenose dolphins. Apparent survival was constant for striped, common and intermediate dolphins (0.94, 95% CI 0.92-0.96 and year-dependent for bottlenose dolphins (an average of 0.85, 95% CI 0.76-0.95. Our work underlines the importance of long-term monitoring to contribute reliable baseline information that can help assess the

  18. A precise gravimetric geoid model for the Gulf of Corinth (KTH-COR12) (United States)

    Daras, I.; Papazissi, K.; Pail, R.; Marinou, A.; Fairhead, D.


    Greece is a very active region where three major tectonic plates, the Eurasia, Africa, and Arabia plates meet. The motions of those major plates drive smaller plates, like the Aegean Sea plate, whose shape and motion determine the locations and focal mechanisms of most earthquakes in the region. The northern edge of the Aegean Sea plate is the Eurasian plate which is a divergent boundary responsible for the formation of the Gulf of Corinth. As a result our area of interest is the most rapidly extending rift system in Greece connected with the highest seismic activities in the Euro-Mediterranean region, an estimate of 1 to 1.5 cm/year of north-south extension, frequent seismic swarms, and destructive historical earthquakes. The key to a better monitoring of the regional earth crustal movements is the use of accurate orthometric heights stemming from GPS geometric heights and a precise geoid model. A precise gravimetric geoid model of the Gulf of Corinth has been computed using the least squares modification of Stokes formula developed at KTH (KTH method). In this method, a stochastic approach applies additional information about the potential coefficients and the gravity anomaly errors in combination with the least squares modification of Stokes kernel to minimize the expected global mean square error (MSE). For this purpose, a dataset of local terrestrial gravity anomalies was combined with a global geopotential model, namely the ITG-Grace2010s satellite-only gravity field model. Areas with no terrestrial gravity information (i.e. sea regions) were filled with EGM08 gravity anomaly values. The SRTM90 digital elevation data from Shuttle Radar Topographic Mission (SRTM) of NASA, with a 90m resolution was chosen for the, essential for the computations, DEM. Additionally, GPS/Levelling, mean sea surface (MSS) and mean dynamic topography (MDT) datasets were used for externally evaluating the geoid model. In this poster the methodology behind the construction of the KTH

  19. The Eighteen Associations of Corinth

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    Benedikt Eckhardt


    Full Text Available Recently offered lists of voluntary associations attested at Corinth can be reduced to two or three dubious cases; in general, the association model for the study of Christian groups needs to be carefully scrutinized aned its local context assessed. 

  20. Greece. (United States)


    A brief description of the population characteristics, geographical features, history, current political situation, economy, energy supply, foreign relations of Greece is presented. Greece's population of 9.95 million is 98% Greek, and the official language is Greek. 97% of the population is Greek Orthodox, and 2% is Muslim. Schooling is compulsory for 9 years, and the literacy rate is 89% for women and 96% for men. The infant mortality rate is 13.8, and life expectancy is 72 years for males and 75 years for female. Greece is situated on the southern tip of the Balkan Peninsula and consists of the mainland, the Peleponnesos, and numerous islands including Crete. Most of the land mass is mountainous, large areas are dry, and only 28% of the land is arable. From the earliest time until recently, emigration from Greece to other countries was a common pattern. Since the 1960s, internal migration to urban areas was the dominant migration trend. Currently, 30% of the population lives in Athens. Despite the growing industrialization and urbanization of the population, the Greeks retain many traditional family and social values. Greece was part of the cradle of civilization, and its history is characterized by the rise of the Minoan culture on Crete, the rise and fall of the Myceneans on the Peleponnesos, the development of the city states of Athens and Sparta, the destruction of Athens during the Peloponnesian War, domination by the Macedonians, the creation of the Hellenistic cilivization, conquest by the Roman Empire, the establishment of the Byzantine Empire, and in 1459 conquest by the Ottoman Empire. In the 1820's Greece fought for and finally won its independence, In World War I Greece fought on the side of the Allies. In World War II, the Greeks successfully resisted an invasion from Italy. In 1941, the country was taken over by the Germans, but the Greek resistance movement continued to fight the Germans until liberation. Between 1944-49, there were 2 unsuccessful

  1. Remote Sensing of Environmental Change in the Antirio Deltaic Fan Region, Western Greece

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    Emmanuel Vassilakis


    Full Text Available In the westernmost region of the rapidly widening Corinth rift, Greece, extensive development of roads, bridges and other human infrastructure has caused continuous environmental change over the past twenty years. River networks, the land surface and the coastal environment, have been altered, especially in the areas corresponding to deltaic fans. In this paper we use earth observation systems that have captured these environmental changes, particularly medium (Landsat TM and ETM+ and high (Quickbird resolution satellite images, to identify environmental changes between the periods 1992, 2000, 2002, and 2005. Six pseudo-color multi-temporal images in different spectral areas were created in order to detect changes to the terrestrial and coastal environment caused mainly by direct or indirect human impact. This methodology provided new data for quantifying significant alterations in the environment on different scales. In many cases this revealed their sequence during the time of observation.

  2. Christian prisoners: fifth and sixth century inscriptions from Corinth ...

    African Journals Online (AJOL)

    Among the inscriptions from Corinth (in publication), there are graffiti carved into the floor of a prison in Corinth. They shed interesting light on the hopes, beliefs and opinions of Christians from late antiquity. This study offers an overview of the insights to be gained from these graffiti. Now that IG IV² 3 Fasc. 3. Inscriptiones ...

  3. Combining surface weathering analyses and cosmogenic 36Cl dating on the Pisia fault plane (Eastern Gulf of Corinth) to reveal the Holocene earthquake history (United States)

    Mechernich, Silke; Schneiderwind, Sascha; Mason, Jack; Papanikolaou, Ioannis; Binnie, Steven A.; Dunai, Tibor J.; Reicherter, Klaus


    The deformation of the Corinth rift (Greece) is distributed along several E-W trending active normal faults like the 25-km-long Pisia fault, which experienced up to 110 cm of coseismic displacement during the 1981 Alkyonides earthquake sequence (Mw 6.7). Ages of paleoearthquakes and slip rate estimates of the Pisia fault are not known so far, despite the faults recent strong shaking and its significant destruction that reached until Athens. We mapped the continuous bedrock fault scarp of the central Pisia fault and revealed at least six different weathering stripes, which are interpreted as coseismic slip that stepwise exhumed the Pisia fault plane. The stripes were detected by color changes, lichen colonization, karst features (pitting and solution flute termination), and by the laser backscatter intensity. Their width and thus the amount of coseismic displacement ranges from 50-110 cm suggesting that six to seven paleoearthquakes of Mw 6.5-6.7 have exhumed the lower 5.15 m of the free-face. Forward modeling of 32 36Cl concentrations indicates that the Pisia fault moved at an average slip rate of 0.7 mm/yr during the Holocene. Modeled ages of individual earthquake events reveal recurrence intervals ranging between 0.2 and 3.1 kyr and a declined tectonic activity from this fault during the past 4.5 kyr. The exposure time in between most events was too narrow to be able to differentiate consecutive events based on cusps in the cosmogenic 36Cl concentrations as there is a rather low local 36Cl production rate (38°N, 625 m a.s.l.). Since such recurrence intervals and earthquake clustering phenomena appear to be quite common on active faults, mapping of independent offset features are often necessary to accurately restore the earthquake history on similarly located bedrock fault planes.

  4. ATLAS Virtual Visit Corinth 26.11.2014

    CERN Multimedia


    Students of the 4th Lyceum of Corinth and teachers from Corinthia's prefecture, will take part to an ATLAS Masterclass organized by physicists of the University of Athens, the Institute of Accelerator Systems & Applications and the Ellinogermaniki School.

  5. The Greek Past and Roman Present: Coinage and Local Identity in Early Roman Corinth

    NARCIS (Netherlands)

    Heijnen, S.J.M.


    Just over a century after its destruction by Lucius Mummius, the ancient Greek city of Corinth was re-founded as a Roman colony. Many contemporary sources present this new Corinth as wholly and unswervingly Roman, with no interest in its Greek heritage. However, Corinthian coins dating from the

  6. Seismic tomography of the Gulf of Corinth: a comparison of methods

    Directory of Open Access Journals (Sweden)

    P. Podvin


    Full Text Available At a local scale, travel-time tomography requires a simultaneous inversion of earthquake positions and velocity structure. We applied a joint iterative inversion scheme where medium parameters and hypocenter parameters were inverted simultaneously. At each step of the inversion, rays between hypocenters and stations were traced, new partial derivatives of travel-time were estimated and scaling between parameters was performed as well. The large sparse linear system modified by the scaling was solved by the LSQR method at each iteration. We compared performances of two different forward techniques. Our first approach was a fast ray tracing based on a paraxial method to solve the two-point boundary value problem. The rays connect sources and stations in a velocity structure described by a 3D B-spline interpolation over a regular grid. The second approach is the finite-difference solution of the eikonal equation with a 3D linear interpolation over a regular grid. The partial derivatives are estimated differently depending on the interpolation method. The reconstructed images are sensitive to the spatial variation of the partial derivatives shown by synthetic examples. We aldo found that a scaling between velocity and hypocenter parameters involved in the linear system to be solved is important in recovering accurate amplitudes of anomalies. This scaling was estimated to be five through synthetic examples with the real configuration of stations and sources. We also found it necessary to scale Pand S velocities in order to recover better amplitudes of S velocity anomaly. The crustal velocity structure of a 50X50X20 km domain near Patras in the Gulf of Corinth (Greece was recovered using microearthquake data. These data were recorded during a field experiment in 1991 where a dense network of 60 digital stations was deployed. These microearthquakes were widely distributed under the Gulf of Corinth and enabled us to perform a reliable tomography of

  7. Dolphins in a Scaled-Down Mediterranean: The Gulf of Corinth's Odontocetes. (United States)

    Bearzi, G; Bonizzoni, S; Santostasi, N L; Furey, N B; Eddy, L; Valavanis, V D; Gimenez, O

    The Gulf of Corinth is a 2400-km 2 semi-enclosed inland system (a mediterraneus) in central Greece. Its continental shelf areas, steep bottom relief, and waters up to 500-900m deep offer suitable habitat to neritic and pelagic species. We used photographic capture-recapture, distribution modelling, and direct observations to investigate the abundance, status, habitat preferences, movements, and group size of four odontocete species regularly observed in the Gulf, based on five years (2011-2015) of survey effort from small boats. Striped dolphins (Stenella coeruleoalba) are more abundant (1324 individuals, 95%CI 1158-1515) than was determined from previous estimates. Striped dolphins appear to be confined to the Gulf, where they favour deep and oligotrophic waters, and were encountered in single-species and mixed-species groups. Short-beaked common dolphins (Delphinus delphis) (22 individuals, 95%CI 16-31), individuals with intermediate pigmentation (possibly striped/common dolphin hybrids) (55, 95%CI 36-83), and a single Risso's dolphin (Grampus griseus) were only encountered in mixed-species groups with striped dolphins. Short-beaked common dolphins constitute a discrete conservation unit (subpopulation), and based on the current estimate, would qualify as Critically Endangered according to International Union for the Conservation of Nature (IUCN) Red List criteria. Common bottlenose dolphins (Tursiops truncatus) (39 animals, 95%CI 33-47) occur in single-species groups; they prefer continental shelf waters and areas near fish farms in the northern sector, and several animals appear to move into and out of the Gulf. Additionally, we contribute records of marine fauna and an assessment of the fishing fleet operating in the Gulf. Our study shows that the importance of this vulnerable marine environment has been underestimated, and management action must be taken to mitigate human impact and ensure long-term protection. © 2016 Elsevier Ltd All rights reserved.

  8. The Corinth Rift Laboratory or an in situ Investigation on Interactions between Fluids and Active Faults

    Directory of Open Access Journals (Sweden)

    F. H. Cornet


    leading to a sudden catastrophic acceleration. Of particular interest is the characterization of the structure of the deforming zones and of the progressive localization of deformation. Special attention is given to the role of fluids but also on the influence of faults on regional fluid flow doi:10.2204/

  9. The hydrogeological structure of fault zones in poorly lithified sediment, Gulf of Corinth rift


    Loveless, Sian


    Often, the structure of fault zones cutting poorly lithified sediment examined in outcrop indicate such fault zones should behave as hydraulic barriers, but hydrological observations indicate they behave as conduit-barriers. This thesis investigates the hydrogeological structure of fault zones cutting poorly lithified sediment to better understand the observed conduit-barrier behaviour. The macro- and micro-structure of fault zones was investigated at outcrops of five fault arrays cutting...

  10. CORINTO Y LAS FLUCTUACIONES DE LA ECONOMÍA GRIEGA DURANTE EL SIGLO V ANTES DE NUESTRA ERA (Corinth and the Fluctuations of Greek Economy during the 5th Century BC

    Directory of Open Access Journals (Sweden)

    Pascual Izquierdo-Egea


    Full Text Available La aplicación del método de valoración contextual al análisis del registro funerario de Corinto, representado por Lequeo (Grecia, confirma una fluctuación de la economía similar a la inferida para la Ampurias griega e Iberia durante todo el siglo V antes de nuestra era; integrada por la etapa de expansión de la primera mitad y la de contracción de la segunda parte de dicha centuria. ENGLISH: Mortuary analysis using the contextual valuation method at Corinth (represented by Lechaion, Greece confirms economic fluctuations similar to that inferred for the Greek Ampurias and Iberia throughout the 5th century BC. These fluctuations were integrated by a stage of expansion in the first half and of contraction in the second part of that century.

  11. Augustan Greece in Strabo’s Geography: A Short Survey

    Directory of Open Access Journals (Sweden)

    Marjeta Šašel Kos


    Full Text Available Strabo dedicated books 8 and 9 of his Geography to Greece, which he describes in great detail. While the greater part of his narrative reads like the description of an earlier Greece, he does include some interesting notes on his own period. His descriptions largely refer to passages in Homer, whom he considers the ultimate authority, since the Iliad and Odyssey formed an important part of the then school curriculum. A recurring observation is that a number of Greek settlements, once densely populated, were in his day deserted. There is no doubt that much of Greece was left waste in the Hellenistic period, especially in the period from Polybius (2nd century B.C. to Strabo (the beginning of the Christian era. While the information from Strabo’s own time represents a very small portion of the two books, it is often of great historical interest. He mentions, for example, the rule of Gaius Iulius Eurycles in Sparta; Eurycles came into conflict with Rome because he allegedly abused his friendship with Augustus, appropriating the island of Cythera and tyrannically extending his power through Laconia. Certainly one of the most influential personages in the Greece of his day, he had inscriptions set up in his honour throughout Laconia and elsewhere in the Peloponnese.  Somewhat more attention is devoted by Strabo to Corinth, which he visited personally. According to him, the city’s affluence was due to trade: lying on the Isthmus, it controlled two ports, Cenchreae, from which ships sailed for Asia, and Lechaeum, which was its link to Greece. Strabo describes the dramatic fall of Corinth: in 146 B.C. it was burnt down by the Roman consul, Lucius Mummius, and robbed of practically all its art works, which were then used to adorn the temples in Rome, in other Italian towns and elsewhere in the Mediterranean, since many were sold as war booty. Strabo mentions that Polybius, who was in Corinth at the time, was particularly saddened by the Roman

  12. Haemoragisk Rift Valley Fever

    DEFF Research Database (Denmark)

    Fabiansen, Christian; Thybo, Søren


    A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described.......A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described....

  13. Continental Rifts and Resources (United States)

    Stein, Holly J.


    Nearly all resource-forming systems involve upward mobility of fluids and melts. In fact, one of the most effective means of chemically transforming the earth's crust can be readily observed in the rift environment. Imposition of rifting is based on deeper stresses that play out in the crust. At its most fundamental level, rifting transfers heat and fluids to the crust. Heat delivered by fluids aids both in transport of metal and maturation of hydrocarbons. The oxidizing capacity of fluids on their arrival in the deep crust, whether derived from old slabs, depleted upper mantle and/or deeper, more primitive mantle, is a fundamental part of the resource-forming equation. Oxidizing fluids transport some metals and breakdown kerogen, the precursor for oil. Reducing fluids transport a different array of metals. The tendency is to study the resource, not the precursor or the non-economic footprint. In doing so, we lose the opportunity to discover the involvement and significance of initiating processes; for example, externally derived fluids may produce widespread alteration in host rocks, a process that commonly precedes resource deposition. It is these processes that are ultimately the transferable knowledge for successful mineral and hydrocarbon exploration. Further limiting our understanding of process is the tendency to study large, highly complex, and economically successful ore-forming or petroleum systems. In order to understand their construction, however, it is necessary to put equal time toward understanding non-economic systems. It is the non-economic systems that often clearly preserve key processes. The large resource-forming systems are almost always characterized by multiple episodes of hydrothermal overprints, making it difficult if not impossible to clearly discern individual events. Understanding what geologic and geochemical features blocked or arrested the pathway to economic success or, even worse, caused loss of a resource, are critical to

  14. North America's Midcontinent Rift: when Rift MET Lip (United States)

    Stein, C. A.; Stein, S. A.; Kley, J.; Keller, G. R., Jr.; Bollmann, T. A.; Wolin, E.; Zhang, H.; Frederiksen, A. W.; Ola, K.; Wysession, M. E.; Wiens, D.; Alequabi, G.; Waite, G. P.; Blavascunas, E.; Engelmann, C. A.; Flesch, L. M.; Rooney, T. O.; Moucha, R.; Brown, E.


    Rifts are segmented linear depressions, filled with sedimentary and igneous rocks, that form by extension and often evolve into plate boundaries. Flood basalts, a class of Large Igneous Provinces (LIPs), are broad regions of extensive volcanism due to sublithospheric processes. Typical rifts are not filled with flood basalts, and typical flood basalts are not associated with significant crustal extension and faulting. North America's Midcontinent Rift (MCR) is an unusual combination. Its 3000-km length formed as part of the 1.1 Ga rifting of Amazonia (Precambrian NE South America) from Laurentia (Precambrian North America) and became inactive once seafloor spreading was established, but contains an enormous volume of igneous rocks. MCR volcanics are significantly thicker than other flood basalts, due to deposition in a narrow rift rather than a broad region, giving a rift geometry but a LIP's magma volume. Structural modeling of seismic reflection data shows an initial rift phase where flood basalts filled a fault-controlled extending basin, and a postrift phase where volcanics and sediments were deposited in a thermally subsiding basin without associated faulting. The crust thinned during rifting and rethickened during the postrift phase and later compression, yielding the present thicker crust. The coincidence of a rift and LIP yielded the world's largest deposit of native copper. This combination arose when a new rift associated with continental breakup interacted with a mantle plume or anomalously hot or fertile upper mantle. Integration of diverse data types and models will give insight into questions including how the magma source was related to the rifting, how their interaction operated over a long period of rapid plate motion, why the lithospheric mantle below the MCR differs only slightly from its surroundings, how and why extension, volcanism, and compression varied along the rift arms, and how successful seafloor spreading ended the rift phase. Papers

  15. Permanent Scatterer InSAR Analysis and Validation in the Gulf of Corinth (United States)

    Elias, Panagiotis; Kontoes, Charalabos; Papoutsis, Ioannis; Kotsis, Ioannis; Marinou, Aggeliki; Paradissis, Dimitris; Sakellariou, Dimitris


    The Permanent Scatterers Interferometric SAR technique (PSInSAR) is a method that accurately estimates the near vertical terrain deformation rates, of the order of ∼1 mm year-1, overcoming the physical and technical restrictions of classic InSAR. In this paper the method is strengthened by creating a robust processing chain, incorporating PSInSAR analysis together with algorithmic adaptations for Permanent Scatterer Candidates (PSCs) and Permanent Scatterers (PSs) selection. The processing chain, called PerSePHONE, was applied and validated in the geophysically active area of the Gulf of Corinth. The analysis indicated a clear subsidence trend in the north-eastern part of the gulf, with the maximum deformation of ∼2.5 mm year-1 occurring in the region north of the Gulf of Alkyonides. The validity of the results was assessed against geophysical/geological and geodetic studies conducted in the area, which include continuous seismic profiling data and GPS height measurements. All these observations converge to the same deformation pattern as the one derived by the PSInSAR technique. PMID:22389587

  16. Tropospheric Ozone: a Menace for Crops and Natural Vegetation in Greece

    Directory of Open Access Journals (Sweden)

    Costas Saitanis

    Full Text Available Based on instrumental monitoring (AOT40s and phytodetection (with Bel-W3 and KK6/5 tobacco cultivars data we evaluated ambient ozone phytotoxicity in Greece. In the greater region of Mesogia-Attica, during the summer of 2000, the year before the new airport Eleftherios Venizelos (March 2001 began operating in this region, the AOT40s (ppb*h were 16,325 over 110 days at Spata; 18,646 over 113 days at Markopoulo; 8,093 over 22 days at Artemis and 16,679 over 121 days in Athens. The Bel- W3 and KK6/5 plants were extensively injured at all places with the greatest injury occurring at Artemis. During the same summer, ozone was also monitored in three rural areas of Corinth, at the Astronomical Observatory of Krionerion, Bogdani Hill and Kiato; The highest average daily AOT40 (192 ppb*h was observed in Krionerio, and it was almost equal to that occurred in Athens (193 ppb*h. Bel-W3 and KK6/5 plants placed at 11 rural areas in Corinth showed extended injury. The following year (2001, high injury was observed on other sets of bioindicator plants exposed in a network of 28 locations throughout the greater area of Volos and Pelion Mountain. Symptoms were more severe at Mortias, Xinovrisi, Tsagarada, Makrinitsa and Chania. The AOT40 (May-July was 11,391 and 10,351 ppb*hours for 2001 and 2002 respectively. Severe ozone-like symptoms have also been observed on field-cultivated grape vines, onion and watermelon plants. Synoptically, our investigations suggest that ozone occurs in the Greek mainland at levels that are potentially phytotoxic for sensitive crop species and for sensitive natural vegetation species including forest trees.

  17. Pathology in Greece. (United States)

    Sakellariou, S; Patsouris, E


    Pathology is the field of medicine that studies diseases. Ancient Greece hosted some of the earliest societies that laid the structural foundations of pathology. Initially, knowledge was based on observations but later on the key elements of pathology were established based on the dissection of animals and the autopsy of human cadavers. Christianized Greece under Ottoman rule (1453-1821) was not conducive to the development of pathology. After liberation, however, a series of events took place that paved the way for the establishment and further development of the specialty. The appointment in 1849 of two Professors of Pathology at the Medical School of Athens for didactical purposes proved to be the most important step in fostering the field of pathology in modern Greece. Presently in Greece there are seven university departments and 74 pathology laboratories in public hospitals, employing 415 specialized pathologists and 90 residents. The First Department of Pathology at the Medical School of Athens University is the oldest (1849) and largest in Greece, encompassing most pathology subspecialties.

  18. Medical education in Greece. (United States)

    Georgantopoulou, Catherine


    This paper aims to present an overview of current medical education in Greece. Greece has a centuries-long tradition in practising and teaching medicine. Medical training, although rigorous, is particularly humane. All Medical Schools in Modern Greece are currently, undergoing a series of changes in an effort to modernize training. The medical education system is also getting harmonized to European Standards for Higher Education, relating to Undergraduate, Postgraduate and Continuous Medical Education of doctors. A specific strength of the Greek educational system is its ethos that emphasises good working conditions and excellent support and supervision at all levels. The current overhauls in Higher Education occupy students, academics and the society at large. Political issues, such as accountability, regulation and autonomy of academia are generating debate. The two-cycle, Bachelor-Master, Undergraduate Model, as described in the Bologna Declaration is still to be implemented. Quality control measures are currently introduced in all academic sectors.

  19. CMS Virtual Tour Greece

    CERN Multimedia

    CERN. Geneva


    More than 500 high-school students from 7 locations in Greece visit virtually the CMS experiment. Read more about this record-breaking event here:

  20. Overeducation in Greece. (United States)

    Patrinos, Harry Anthony


    Investigates the question of socioeconomic background and estimates the incidence and labor market impacts of overeducation using data from Greece. Suggests that overeducation is a phenomenon that affects workers as they make their way through the labor market, and that overeducation is concentrated among university-educated workers with a…

  1. Cenozoic rifting in the West Antarctic Rift System (United States)

    Granot, R.; Cande, S. S.; Stock, J. M.; Clayton, R. W.; Davey, F. J.


    The West Antarctic Rift System (WARS) experienced two episodes of Cenozoic rifting. Seafloor spreading at the Adare spreading axis, north of the Ross Sea, from Middle Eocene to Late Oligocene time (43 - 26 Ma), was directly linked with motions within the WARS. For this time interval, marine magnetic anomalies within the Adare Basin and structural features within the Ross Sea constrain the motion between East and West Antarctica. During this episode, widespread intrusive activity took place in the continental part of the rift. Subsequent Late Oligocene until present-day (26 - 0 Ma) extension was characterized by a transition to volcanic activity. Yet, the details of extension during this episode have been poorly resolved. We present preliminary results of new seismic reflection and seafloor mapping data acquired on geophysical cruise 07-01 aboard the R/VIB Nathaniel Palmer in the northern part of the rift. Our results suggest that the style of deformation changed from spreading-related faulting into diffuse normal faulting (tilted blocks) that trend NE-SW with little resultant E-W extension. Recent volcanism is distributed throughout but tends to align with the NE-SW trend, into a localized zone. Formation of the Terror Rift, Ross Sea, within the same time frame suggests that the pole of rotation has changed its position, reflecting a change in the relative magnitudes of tensile stresses along the rift. Moreover, this change was accompanied with a sharp decrease of extension rates.

  2. Greece at CERN

    CERN Multimedia

    CERN Press Office. Geneva


    Greece, one of CERN*'s founding Member States, inaugurated its first Industrial Exhibition at the Meyrin site on Tuesday, 14 October. After a meeting with CERN's Director General, Professor Christopher Llewellyn Smith, Professor Emmanuel Frangoulis, the General Secretary of the Greek Ministry of Industry, accompanied by Prof Emmanuel Floratos, Greek delegate to CERN council visited the DELPHI experiment on the LEP collider, guided by Andromachi Tsirou, a Greek physicist.

  3. Environmental performance reviews: Greece

    Energy Technology Data Exchange (ETDEWEB)



    This report reviews Greece's environmental performance in the light of domestic objectives and international commitments. It is organised in three parts: Part 1 is entitled 'Pollution Control and Nature Conservation; and focuses on water, air management, and biodiversity and nature conservation; Part 2 is entitled 'Integration of Policies' and focuses on institutional aspects and on how policies concerning economics, coastal and urban management, and tourism are integrated with environmental policies; and Part 3 is entitled 'Co-operation with the International Community' and focuses on international environmental topics concerning Greece. In 1997, emissions of sulphur dioxide in Greece were twice the OECD Europe average per GDP, as well as being high in terms per capita. About 70% of these emissions come from power plants, largely fired with local lignite of poor quality. Of late, however, the use of lignite has levelled off, to the accompaniment of an increased use of natural gas. Moreover some units of the country's largest power station, Megalopolis, have recently been equipped for flue-gas desulphurization and two of the refineries have expanded their capacity for desulphurizing oil. Amongst recommendations made by the OECD is a programme for energy conservation and energy efficiency, promotion of natural gas and cleaner vehicles, and improved monitoring and enforcement of regulations. 17 figs., 31 tabs., 4 apps.

  4. Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont (United States)

    Piatak, Nadine M.; Argue, Denise M.; Seal, Robert R.; Kiah, Richard G.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.


    The Pike Hill Copper Mine Superfund site in Corinth, Orange County, Vermont, includes the Eureka, Union, and Smith mines along with areas of downstream aquatic ecosystem impairment. The site was placed on the U.S. Environmental Protection Agency (USEPA) National Priorities List in 2004. The mines, which operated from about 1847 to 1919, contain underground workings, foundations from historical structures, several waste-rock piles, and some flotation tailings. The mine site is drained to the northeast by Pike Hill Brook, which includes several wetland areas, and to the southeast by an unnamed tributary that flows to the south and enters Cookville Brook. Both brooks eventually drain into the Waits River, which flows into the Connecticut River. The aquatic ecosystem at the site was assessed using a variety of approaches that investigated surface-water quality, sediment quality, and various ecological indicators of stream-ecosystem health. The degradation of surface-water quality is caused by elevated concentrations of copper, and to a lesser extent cadmium, with localized effects caused by aluminum, iron, and zinc. Copper concentrations in surface waters reached or exceeded the USEPA national recommended chronic water-quality criteria for the protection of aquatic life in all of the Pike Hill Brook sampling locations except for the location farthest downstream, in half of the locations sampled in the tributary to Cookville Brook, and in about half of the locations in one wetland area located in Pike Hill Brook. Most of these same locations also contained concentrations of cadmium that exceeded the chronic water-quality criteria. In contrast, surface waters at background sampling locations were below these criteria for copper and cadmium. Comparison of hardness-based and Biotic Ligand Model (BLM)-based criteria for copper yields similar results with respect to the extent or number of stations impaired for surface waters in the affected area. However, the BLM

  5. Structural style of the Turkana Rift, Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Dunkelman, T.J.; Karson, J.A.; Rosendahl, B.R.


    Multifold seismic reflection and geologic mapping in part of the eastern branch of the East African Rift system of northern Kenya reveal a major rift structure containing at least 3 km of Neogene sediment fill beneath Lake Turkana. This includes a series of half-graben basins, with centrally located quaternary volcanic centers, which are linked end-to-end by structural accommodation zones. Whereas the geometry of rifting is similar to that of the nonvolcanic western branch of the East African Rift system, the Turkana half-grabens are much smaller and may reflect extension of a thinner lithosphere or development of more closely spaced fracture patterns during rift evolution, or both.


    African Journals Online (AJOL)

    Department of Geology, University of Dar es Salaam. PO. Box 35052, Dar es Salaam, Tanzania. ABSTRACT ,. Detailed geological and structural investigations at the northwestern scarp of the Cenozoic Kilombero Rift allow the drawing of its structural evolution and establishment of stress conditions that prevailed at the ...

  7. Greece Experience of International Tourism

    Directory of Open Access Journals (Sweden)

    Beslan V. Labzhaniya


    Full Text Available Tourism offers a real opportunity to invite investments, decline unemployment and increase production, which will help to overcome crisis and come to sustainable development, badly needed for Greece now.

  8. Greece: Too Strategic To Fail (United States)


    Albanian habiliments.”69 Later the Bavarian-transplanted Greek monarchy used the Guaranteed Loan installments to bolster “The army, the civil list...Metternich’s letter indicates Greece had made little headway in developing an economy capable of repaying its debts. It seems the monarchy was more interested...The bond of a common religion decided the sympathies of Greece in favour of Russia.”82 The Greek monarchy was also directly tied to Russia. On 27

  9. Magmatism in rifting and basin formation (United States)

    Thybo, H.


    Whether heating and magmatism cause rifting or rifting processes cause magmatic activity is highly debated. The stretching factor in rift zones can be estimated as the relation between the initial and the final crustal thickness provided that the magmatic addition to the crust is insignificant. Recent research demonstrates substantial magmatic intrusion into the crust in the form of sill like structures in the lowest crust in the presently active Kenya and Baikal rift zones and the DonBas palaeo-rift zone in Ukraine. This result may be surprising as the Kenya Rift is associated with large amounts of volcanic products, whereas the Baikal Rift shows very little volcanism. Identification of large amounts of magmatic intrusion into the crust has strong implications for estimation of stretching factor, which in the case of Baikal Rift Zone is around 1.7 but direct estimation gives a value of 1.3-1.4 if the magmatic addition is not taken into account. This may indicate that much more stretching has taken place on rift systems than hitherto believed. Wide sedimentary basins may form around aborted rifts due to loading of the lithosphere by sedimentary and volcanic in-fill of the rift. This type of subsidence will create wide basins without faulting. The Norwegian- Danish basin in the North Sea area also has subsided gradually during the Triassic without faulting, but only few rift structures have been identified below the Triassic sequences. We have identified several mafic intrusions in the form of large batholiths, typically more than 100 km long, 20-40 km wide and 20 km thick. The associated heating would have lifted the surface by about 2 km, which may have been eroded before cooling. The subsequent contraction due to solidification and cooling would create subsidence in a geometry similar to basins that developed by loading. These new aspects of magmatism will be discussed with regard to rifting and basin formation.

  10. Neotectonics of the Roer Valley Rift System, the Netherlands.

    NARCIS (Netherlands)

    Houtgast, R.F.; van Balen, R.T.


    The Roer Valley Rift System (RVRS) is located in the southern part of the Netherlands and adjacent parts of Germany and Belgium. The last rifting episode of the RVRS started in the Late Oligocene and is still ongoing. The present-day seismic activity in the rift system is part of that last rifting

  11. Historical earthquake investigations in Greece

    Directory of Open Access Journals (Sweden)

    K. Makropoulos


    Full Text Available The active tectonics of the area of Greece and its seismic activity have always been present in the country?s history. Many researchers, tempted to work on Greek historical earthquakes, have realized that this is a task not easily fulfilled. The existing catalogues of strong historical earthquakes are useful tools to perform general SHA studies. However, a variety of supporting datasets, non-uniformly distributed in space and time, need to be further investigated. In the present paper, a review of historical earthquake studies in Greece is attempted. The seismic history of the country is divided into four main periods. In each one of them, characteristic examples, studies and approaches are presented.

  12. Greece welcomes CERN Accelerator School

    CERN Multimedia

    CAS School


    The CERN Accelerator School (CAS) and the University of the Aegean jointly organised a course on intermediate-level Accelerator Physics in Chios, Greece, from 19 to 30 September, 2011.   CAS Students pose for a group photo in Chios, Greece. This course followed the established format of the intermediate school, with lectures in the mornings and specialised courses in the afternoons. The latter provided “hands-on” education and experience in three topics: “RF Measurement Techniques”, “Beam Instrumentation and Diagnostics” and “Optics Design and Correction”.  Participants selected one of the three courses and followed the chosen topic throughout the school. Guided studies and tutorials on core subjects, seminars and a poster session completed the programme. An excursion included a visit to the Nea Moni monastery, a guided tour of two medieval villages, Pyrgi and Mesta, and finished with a typical Greek me...

  13. Penetration of Photovoltaics in Greece


    Eugenia Giannini; Antonia Moropoulou; Zacharias Maroulis; Glykeria Siouti


    Recently, an interesting experiment was completed in Greece concerning photovoltaic penetration into the electricity production sector. Based on the relevant laws and in accordance to the related European directives, an explosive penetration process was completed in less than three years, resulting in a 7% share of photovoltaics in electricity production instead of the previous negligible share. The legislation was based on licensing simplification and generous feed-in-tariffs. This approach ...

  14. Foreign female immigrants in Greece


    Fakiolas, Rossetos


    Strong push, pull and network formation factors account for the over 600,000 foreign immigrants, mostly economic and with irregular status, who have been since the early 1990s in Greece, a traditionally emigration country. Over a quarter of them are females who have come alone, marking the new trend in female migration. And like their male counterparts, they find jobs due to their wage and job flexibility. The recent Greek policy to regularise irregular or undocumented immigrants (UI), that i...

  15. Health economic evaluation in Greece. (United States)

    Rovithis, Dimitrios


    There is a growing volume of literature on health economic evaluation, with this form of analysis becoming increasingly influential at the decision-making level worldwide. The purpose of this study was to review the current state of health economic evaluation in Greece, with a view to uncovering reasons why its use in this country is limited. A search of the NHS Economic Evaluation Database was undertaken. The search included cost, cost-of-illness, cost-minimization, cost-effectiveness, cost-consequences, cost-utility, and cost-benefit analyses and was narrowed only to Greek authors undertaking solo or joint health economic evaluation in Greece. The search revealed that, in Greece, very little health economic evaluation has been undertaken. The main reason for the lack of interest is that the current chaotic healthcare system structure and financing does not provide the appropriate incentives to stimulate a powerful interest in this type of research. This condition is a result of the lack of a long-term national health policy and the hesitation of the present and past Greek governments to date to proceed to large-scale reforms because of political considerations. The Greek governments have also been content with the good health indicators being achieved. Even if it is accepted that good health prevails in Greece, slower economic growth rates, an ageing population, and the continuous immigration will place increasing pressure on healthcare resources and will necessitate a more rational use of these resources. Health economic evaluation, by weighing benefits against costs, therefore, has an important role to play.

  16. Regional seismic hazard for Revithoussa, Greece: an earthquake early warning Shield and selection of alert signals

    Directory of Open Access Journals (Sweden)

    Y. Xu


    Full Text Available The feasibility of an earthquake early warning Shield in Greece is being explored as a European demonstration project. This will be the first early warning system in Europe. The island of Revithoussa is a liquid natural gas storage facility near Athens from which a pipeline runs to a gas distribution centre in Athens. The Shield is being centred on these facilities. The purpose here is to analyze seismicity and seismic hazard in relation to the Shield centre and the remote sensor sites in the Shield network, eventually to help characterize the hazard levels, seismic signals and ground vibration levels that might be observed or create an alert situation at a station. Thus this paper mainly gives estimation of local seismic hazard in the regional working area of Revithoussa by studying extreme peak ground acceleration (PGA and magnitudes. Within the Shield region, the most important zone to be detected is WNW from the Shield centre and is at a relatively short distance (50 km or less, the Gulf of Corinth (active normal faults region. This is the critical zone for early warning of strong ground shaking. A second key region of seismicity is at an intermediate distance (100 km or more from the centre, the Hellenic seismic zone south or southeast from Peloponnisos. A third region to be detected would be the northeastern region from the centre and is at a relatively long distance (about 150 km, Lemnos Island and neighboring region. Several parameters are estimated to characterize the seismicity and hazard. These include: the 50-year PGA with 90% probability of not being exceeded (pnbe using Theodulidis & Papazachos strong motion attenuation for Greece, PGANTP; the 50-year magnitude and also at the 90% pnbe, M50 and MP50, respectively. There are also estimates of the earthquake that is most likely to be felt at a damaging intensity level, these are the most perceptible earthquakes at intensities VI, VII and VIII with magnitudes MVI, MVII and MVIII

  17. First results from an earthquake early warning system in Western Greece with special focus on the city of Patras and the Rion Antirion bridge (United States)

    Sokos, Efthimios; Tselentis, Akis; Paraskevopoulos, Paraskevas; Serpetsidaki, Anna; Stathopoulos, Aris; Panagis, Akis


    Patras with almost 250.000 residents is the third largest city in Greece and it is an ideal candidate for an Earthquake Early Warning application due to its high seismic hazard, its existing research infrastructure, and the presence of critical structures such as the Rion Antirion bridge. This bridge, completed in 2004 by the GEFYRA consortium, is the world's longest multi-span cable-stayed bridge, it crosses the Gulf of Corinth near Patras linking the town of Rion on the Peloponnese to Antirion on mainland Greece. It is a very important infrastructure for the road network in central Greece since it is the only connection between Peloponnese and central Greece. Patras is located a few hundreds of kilometres from the Hellenic Arc, where very strong and potentially damaging events occur. This distance is large enough to provide a few tens of seconds of warning time, provided that a dense seismic network exists. Under the REAKT project the Virtual Seismologist software was installed in Patras Seismological Laboratory (UPAT) as an early warning system and we present here its initial evaluation. The software was installed in UPAT in May 2013 and is using broad band data from the Hellenic Unified Seismic Network and strong motion data from six accelerographs installed during the first year of REAKT project. During this first year of operation VS has processed a few thousand events. In general the software performs quite well in magnitude estimation (regression between officially reported magnitude and VS magnitude gives correlation coefficient equal to 0.84). The average time that VS needs to evaluate the first magnitude estimate is rather large, of the order of tens of seconds and not yet satisfactory for operational use of early warning. Results of the initial period of early warning operation in western Greece suggest that the network density needs to be enhanced by the addition of extra stations. Nevertheless the application of early warning in the area seems to be

  18. Contrasted continental rifting via plume-craton interaction : Applications to Central East African Rift

    NARCIS (Netherlands)

    Koptev, Alexander; Burov, Evgueni; Calais, Eric; Leroy, Sylvie; Gerya, Taras; Guillou-Frottier, Laurent; Cloetingh, Sierd

    The East African Rift system (EARS) provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides of the old thick Tanzanian craton embedded in a younger lithosphere. Data on the

  19. The endemic flora of Greece

    DEFF Research Database (Denmark)

    Tan, Kit


    The Balkan Peninsula has a rich endemic flora estimated as between 2600 and 2700 taxa; c. 750 are restricted to Greece. Conservationists consider the endemic flora of a country needs protection for all time; there is a tendency to paint an alarming picture. However, unless one knows something...... or quite a lot about the plants, no intelligent steps can be taken towards protecting them. 520 of the c. 750 endemics are listed on the Red Data "endangered list" by the Council of Europe in 1986 but few know the nature or extent of the threat. Work is currently in preparation on an Endemic Flora...

  20. Geothermal resources of rifts: A comparison of the rio grande rift and the salton trough (United States)

    Swanberg, Chandler A.


    The Rio Grande Rift and the Salton Trough are the best developed rift systems in the United States and both share many features common to rifts in general, including geothermal resources. These two rifts have different tectonic and magmatic histories, however, and these differences are reflected in the nature of their geothermal resources. The Salton Trough is a well developed and successful rift. It is the landward extension of the Gulf of California spreading center, which has separated Baja, California, from the remainder of Mexico. Quaternary silicic magmatization has occurred and several of the geothermal resources are associated with recent rhyolitic intrusions. Such resources tend to be high temperature (> 200°C). Greenschist facies metamorphism has been observed in several of the geothermal wells. Localized upper crustal melting is a distinct possibility and there is increasing speculation that very high temperature (> 300°C) geothermal fluids may underlie a large portion of the central trough at depths in excess of 4 km. Low temperature geothermal resources associated with shallow hydrothermal convection are less common and tend to be located on the flanks of the trough or in the Coachella Valley to the north of the zone of active rifting. In contrast, the Rio Grande Rift is less well developed. Recent volcanism consists primarily of mantle-derived basalts, which have not had sufficient residence time within the crust to generate significant crustal melting. The geothermal resources within the Rio Grande Rift do not correlate well with these young basalts. Rather, the quantity of geothermal resources are low temperature (resources are less common and the only discovered example is the Valles Caldera of northern New Mexico ( T = 250-300°C). The deep interiors of the sedimentary basins of the Rio Grande Rift do not appear to be major geothermal exploration targets.

  1. Submarine thermal springs on the Galapagos Rift (United States)

    Corliss, J.B.; Dymond, J.; Gordon, L.I.; Edmond, J.M.; Von Herzen, R. P.; Ballard, Richard D.; Green, K.; Williams, D.; Bainbridge, A.; Crane, K.; Van Andel, T. H.


    The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis

  2. Thermomechanical models of the Rio Grande rift

    Energy Technology Data Exchange (ETDEWEB)

    Bridwell, R.J.; Anderson, C.A.


    Fully two-dimensional, coupled thermochemical solutions of a continental rift and platform are used to model the crust and mantle structure of a hot, buoyant mantle diapir beneath the Rio Grande rift. The thermomechanical model includes both linear and nonlinear laws of the Weertman type relating shear stress and creep strain rate, viscosity which depends on temperature and pressure, and activation energy, temperature-dependent thermal conductivity, temperature-dependent coefficient of thermal expansion, the Boussinesq approximation for thermal bouyancy, material convection using a stress rate that is invariant to rigid rotations, an elastically deformable crust, and a free surface. The model determines the free surface velocities, solid state flow field in the mantle, and viscosity structure of lithosphere and asthenosphere. Regional topography and crustal heat flow are simulated. A suite of symmetric models, assumes continental geotherms on the right and the successively increasing rift geotherms on the left. These models predict an asthenospheric flow field which transfers cold material laterally toward the rift at > 300 km, hot, buoyant material approx. 200 km wide which ascends vertically at rates of 1 km/my between 175 to 325 km, and spreads laterally away from the rift at the base of the lithosphere. Crustal spreading rates are similar to uplift rates. The lithosphere acts as stiff, elastic cap, damping upward motion through decreased velocities of 1 km/10 my and spreading uplift laterally. A parameter study varying material coefficients for the Weertman flow law suggests asthenospheric viscosities of approx. 10/sup 22/ to 10/sup 23/ poise. Similar studies predict crustal viscosities of approx. 10/sup 25/ poise. The buoyant process of mantle flow narrows and concentrates heat transport beneath the rift, increases upward velocity, and broadly arches the lithosphere. 10 figures, 1 table.

  3. Foreign Guests in Ancient Greece

    Directory of Open Access Journals (Sweden)

    Zora Žbontar


    Full Text Available Xenía was a special relationship between a foreign guest and his host in Ancient Greece. The ritual of hosting a foreigner included an exchange of objects, feasting, and the establishment of friendship between people from different social backgrounds. This relationship implied trust, loyalty, friendship, and mutual aid between the people involved. Goods and services were also exchanged without any form of payment. There were no formal laws governing xenía – it was based entirely on a moral appeal. Mutual appreciation between the host and the guest was established during the ritual, but the host did retain a certain level of superiority over the guest. Xenía was one of the most important institutions in Ancient Greece. It had a lot of features and obligations similar to kinship and marriage. In literary sources the word xénos varies in meaning from “enemy stranger”, “friendly stranger”, “foreigner”, “guest”, “host” to “ritual friend”, and it is often hard to tell which usage is appropriate in a given passage. The paper describes the emphasis on hospitality towards foreigners. It presents an example of a depiction indicating xenía is presented, as well as several objects which were traded during the ritual. The paper also addresses the importance of hospitality in Greek drama in general, especially with examples of violations of the hospitality code.

  4. A finite amplitude necking model of rifting in brittle lithosphere (United States)

    Lin, Jian; Parmentier, E. M.


    We formulate a mechanical model describing the formation of rifts as finite amplitude necking of an elastic-plastic layer overlying a fluid substrate. A perfectly plastic rheology is a continuum description of faulting in rift zones. Two important aspects of rift evolution are illustrated by this model: the evolution of the rift width as extension proceeds and the finite strain that occurs. A region at yield initially develops with a width determined by the thickness of the brittle layer, and the internal deformation within this yield zone is proportional to the topographic slope. As extension proceeds, the surface within the rift subsides, and the width of the subsiding yield zone decreases. At any stage of rifting, material in regions just outside the yield zone is deformed but no longer deforming. The width of these deformed regions increases with increasing extension. Vertical forces due to the mass deficit of the rift depression will flex the elastic layer outside the yield zone, creating flanking uplifts. The external force required to maintain active rifting increases with the amount of lithospheric stretching, indicating that rifting is a quasi-static, stable process. Because the yield zone will revert to elastic behavior if the external force causing extension is removed, the model predicts that the rift depression and flanking uplifts will be preserved after extension stops. Our simple mechanical model demonstrates the inherent relationship among graben formation, lithospheric thinning, and rift shoulder uplift in rift zones.

  5. Molecular Epidemiology of Rift Valley Fever Virus (United States)

    Grobbelaar, Antoinette A.; Weyer, Jacqueline; Leman, Patricia A.; Kemp, Alan; Paweska, Janusz T.


    Phylogenetic relationships were examined for 198 Rift Valley fever virus isolates and 5 derived strains obtained from various sources in Saudi Arabia and 16 countries in Africa during a 67-year period (1944–2010). A maximum-likelihood tree prepared with sequence data for a 490-nt section of the Gn glycoprotein gene showed that 95 unique sequences sorted into 15 lineages. A 2010 isolate from a patient in South Africa potentially exposed to co-infection with live animal vaccine and wild virus was a reassortant. The potential influence of large-scale use of live animal vaccine on evolution of Rift Valley fever virus is discussed. PMID:22172568

  6. An attempt to model rift propagation (United States)

    Zwaan, Frank; Schreurs, Guido


    Rift propagation is along-strike growth of an initial small rift structure. Since rift propagation is a major factor in continent-break up (e.g. the opening of the Atlantic) we started a series of models to investigate associated tectonic processes. These analogue models involve either standard extension (continuous along-strike) or scissor-like extension (with an along-strike gradient and a rotation axis). Both the standard and scissor set-ups involve a base of foam and plastic components that transfers distributed extension to the overlying model materials as the model sidewalls are moved apart. The difference between the standard set-up and the scissor set-up is that the sidewalls move apart in a parallel fashion in the former, while in the latter, the sidewalls move around a rotation axis, causing a scissor-like deformation gradient. We use quartz sand layer for the brittle upper crust and a viscous sand/silicone mixture for ductile lower crust (total 8 cm, 1 cm = 5 km). Lines of semi-circular silicone (seeds) on top of the basal viscous layer act as weak zones along deformation focuses because the stronger sand layer on top is thinner and therefore weaker. These 0.75 cm thick seeds are situated at one end of the model (ca. 20 cm long on a model length of 80-90 cm), to initiate a rift structure from which rift propagation could start. Both set-ups encounter the same problems. In contrast with our previous model series (e.g. Zwaan et al., 2016), the seeds cause little localization and almost no rift propagation. Instead, extensional faulting occurs mostly along the sidewalls, especially away from the seeds. Apparently, the models need a seed or weak zone to localize deformation, otherwise the model boundaries provide the weaknesses along which faulting occurs. Tests with lower extension velocities (which should improve rift localization due to lower brittle-ductile coupling) did not improve the results. Neither did the application of a thicker seed (ø up to 1

  7. Volcanic field elongation, vent distribution and tectonic evolution of continental rift: The Main Ethiopian Rift example (United States)

    Mazzarini, Francesco; Le Corvec, Nicolas; Isola, Ilaria; Favalli, Massimiliano


    Magmatism and faulting operate in continental rifts and interact at a variety of scales, however their relationship is complex. The African rift, being the best example for both active continental rifting and magmatism, provides the ideal location to study the interplay between the two mechanisms. The Main Ethiopian Rift (MER), which connects the Afar depression in the north with the Turkana depression and Kenya Rift to the south, consists of two distinct systems of normal faults and its floor is scattered with volcanic fields formed by tens to several hundreds monogenetic, generally basaltic, small volcanoes and composite volcanoes and small calderas. The distribution of vents defines the overall shape of the volcanic field. Previous work has shown that the distribution of volcanic vents and the shape of a field are linked to its tectonic environment and its magmatic system. In order to distinguish the impact of each mechanism, we analyzed four volcanic fields located at the boundary between the central and northern MER, three of them (Debre Zeyit, Wonji and Kone) grew in the rift valley and one (Akaki) on the western rift shoulder. The elongation and shape of the fields were analyzed based on their vent distribution using the Principal Component Analysis (PCA), the Vent-to-Vent Distance (VVD), and the two dimensional symmetric Gaussian kernel density estimate methods. We extracted from these methods several parameters characterizing the spatial distribution of points (e.g., eccentricity (e), eigenvector index (evi), angular dispersion (Da)). These parameters allow to define at least three types of shape for volcanic fields: strong elongate (line and ellipse), bimodal/medium elongate (ellipse) and dispersed (circle) shapes. Applied to the natural example, these methods well differentiate each volcanic field. For example, the elongation of the field increases from shoulder to rift axis inversely to the angular dispersion. In addition, the results show that none of

  8. Molecular Rift: Virtual Reality for Drug Designers. (United States)

    Norrby, Magnus; Grebner, Christoph; Eriksson, Joakim; Boström, Jonas


    Recent advances in interaction design have created new ways to use computers. One example is the ability to create enhanced 3D environments that simulate physical presence in the real world--a virtual reality. This is relevant to drug discovery since molecular models are frequently used to obtain deeper understandings of, say, ligand-protein complexes. We have developed a tool (Molecular Rift), which creates a virtual reality environment steered with hand movements. Oculus Rift, a head-mounted display, is used to create the virtual settings. The program is controlled by gesture-recognition, using the gaming sensor MS Kinect v2, eliminating the need for standard input devices. The Open Babel toolkit was integrated to provide access to powerful cheminformatics functions. Molecular Rift was developed with a focus on usability, including iterative test-group evaluations. We conclude with reflections on virtual reality's future capabilities in chemistry and education. Molecular Rift is open source and can be downloaded from GitHub.

  9. Root zone of a continental rift

    DEFF Research Database (Denmark)

    Kirsch, Moritz; Svenningsen, Olaf


    Mafic magmatic rocks formed between ca. 615 and 560 Ma along the Neoproterozoic margins of Baltica and Laurentia are classically attributed to continental rifting heralding the opening of the Iapetus Ocean. We report new data for the Kebnekaise Intrusive Complex (KIC) exposed in the Seve Nappes i...

  10. Rift Valley fever: A neglected zoonotic disease? (United States)

    Rift Valley fever (RVF) is a serious viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. First isolated in Kenya during an outbreak in 1930, subsequent outbreaks have had a significant impact on animal and human health, as well as national economies. ...

  11. Penetration of Photovoltaics in Greece

    Directory of Open Access Journals (Sweden)

    Eugenia Giannini


    Full Text Available Recently, an interesting experiment was completed in Greece concerning photovoltaic penetration into the electricity production sector. Based on the relevant laws and in accordance to the related European directives, an explosive penetration process was completed in less than three years, resulting in a 7% share of photovoltaics in electricity production instead of the previous negligible share. The legislation was based on licensing simplification and generous feed-in-tariffs. This approach transformed photovoltaic technology from a prohibitively expensive to a competitive one. This work aims to summarize the relevant legislation and illustrate its effect on the resulting penetration. A sigmoid-shape penetration was observed which was explained by a pulse-type driving force. The return on investment indicator was proposed as an appropriate driving force, which incorporates feed-in-tariffs and turnkey-cost. Furthermore, the resulting surcharge on the electricity price due to photovoltaic penetration was also analyzed.

  12. Rio Grande Rift: History of Tectonic Opening and Magmatism (United States)

    van Wijk, J.; Axen, G. J.; Koning, D.


    We describe the mid-Miocene to present opening history of the Rio Grande rift from tectonic subsidence patterns, published Quaternary fault activity, and spatial, temporal and geochemical distributions of volcanism. Rift opening was quite fast until 8 Ma, with tectonic subsidence rates comparable to those of the pre-rupture phase of rifted continent margins, but post-8 Ma rates are slower in all studied localities. Integration of age control reveals that a rift-margin unconformity formed between 8.5 and 3.5 Ma, its exact duration varying depending on location. This partly coincides with uplift of the Ogallala formation in the western Great Plains. The widespread extent of the unconformity suggest that the unconformity records a region-wide dynamic uplift event, possibly resulting from mantle upwelling below the region. This is supported by geoid analyses. The unconformity postdates a change in relative plate motion between the North American and Pacific plates, which may account for the post-8 Ma decrease in subsidence rates. Distribution of Quaternary fault activity is concentrated on the border faults in the northern basins where the rift is in a juvenile stage, but distributed on intra-basin faults further south in the rift where the crust is thinned more. Our analyses show that volcanism in the Rio Grande rift has been of mainly basaltic composition since the Miocene; volcanism during early rifting ranged from basalt to rhyolite. Volcanism has not been evenly distributed in the rift, but concentrated in three large volcanic fields that were located outside of the main rift prior to rift opening, and along the Jemez Lineament which crosses the Rio Grande rift, with sporadic volcanic activity elsewhere. The southern portion of the rift has experienced less volcanic activity than the northern rift, perhaps because it is underlain by fast seismic wave velocity upper mantle that may be linked to colder or compositionally different (Farallon plate subduction related


    Directory of Open Access Journals (Sweden)



    Full Text Available With the economic crisis of recent years there is a wider discussion on issues of employment and unemployment in Greece. Development, attracting new investments, creating new jobs, unemployment rates, brain drain are some of the issues that interests the political, economic and social carriers of the country. This paper presents data on employment and unemployment in Greece for the last decade. Under this framework, data are presented and the relevant findings are discussed.

  14. The Ancient Greece's roots of Olimpism

    Directory of Open Access Journals (Sweden)

    Bubka Sergej Nazarovich


    Full Text Available The paper focused on the phenomena of sport in Ancient Greece along with history, traditions, religion, education, culture and art. Economic and political conditions are analysed which promote or hamper development of Olympic Games in Ancient Greece. Exceptional stability of Ancient Olympic games during more than eleven centuries are noted as well as their influence on the life of Greek polices of those days. Hellenistic period needs of individual consideration.



    Charalambos Tsardanidis; Christina Christodoulidou


    This article analyses the presence of the population of Asian origin in Greece, a relatively recent phenomenon on which academic studies and available statistics are still fairly scarce. Following an analysis of the available sources, and based on their own research, the authors reach the conclusion that while it is from being the majority case, it is clear that Asian communities are notable for their autonomous professional and entrepreneurial activity in Greece, and furthermore that unlike ...

  16. Structural inheritance, segmentation, and rift localization in the Gulf of Aden oblique rift (United States)

    Bellahsen, Nicolas; Leroy, Sylvie; Autin, Julia; d'Acremont, Elia; Razin, Philippe; Husson, Laurent; Pik, Raphael; Watremez, Louise; Baurion, Celine; Beslier, Marie-Odile; Khanbari, Khaled; Ahmed, Abdulhakim


    The structural evolution of the Gulf of Aden passive margins was controlled by its oblique divergence kinematics, inherited structures, and the Afar hot spot. The rifting between Arabia and Somalia started at 35 Ma just before the hot spot paroxysm (at 30Ma) and lasted until 18Ma, when oceanic spreading started. Fieldwork suggests that rift parallel normal faults initiated in the (future) distal margins, after a first stage of distributed rifting, and witness the rift localization, as confirmed by 4-layer analogue models. These faults arise either from crust or lithosphere scale buoyancy forces that are strongly controlled by the mantle temperature under the influence of the Afar hot spot. This implies a transition from a distributed mode to a localized one, sharper, both in space and time, in the West (close to the hot spot) than in the East (far away from the hot spot). In this framework, first order transform F.Z. are here (re-) defined by the fact that they deform continental crust. In the Gulf of Aden, as well as in other continental margins, it appears that these F.Z. are often, if not always, located at continental transfer or "transform" fault zones. Our detailed field-study of an offshore transfer fault zone in the southeastern Gulf of Aden (Socotra Island) shows that these structures are long-lived since early rifting until post rift times. During the early rifting, they are inherited structures reactivated as oblique normal faults before accommodating strike-slip motion. During the Ocean-Continent Transition (OCT) formation ("post syn-rift" times), a significant uplift occurred in the transfer fault zone footwall as shown by stratigraphic and LT thermochronology data. Second order transform F.Z. are defined as deforming only the OCT, thus initiated at the moment of its formation. In the western Gulf of Aden, the hot spot provoked a rift localization strongly oblique to the divergence and, as a consequence, several second order transform F.Z. formed (as

  17. Tectonic Evolution of the Terceira Rift (Azores) (United States)

    Stratmann, Sjard; Huebscher, Christian; Terrinha, Pedro; Ornelas Marques, Fernando; Weiß, Benedik


    The Azores Plateau is located in the Central Atlantic at the Eurasian, Nubian and North-American plates (RRT) Azores Triple Junction. The Terceira Rift (TR) connects the Mid-Atlantic Ridge with the Gloria Fault, hence establishing a transtensional-transform present day plate boundary between the Eurasian and the Nubian plates. Three volcanic islands arose along the TR, Graciosa, Terceira and Sao Miguel. In the geological past, the plate boundary in the Azores area between the Eurasian and Nubian plates was located further south at the East Azores Fracture Zone. The timing of the plate boundary jump, which marks the onset of rifting along the TR, is heavily disputed. Published ages vary from 36 to 1 Ma. Based on bathymetric data and high-resolution marine 2D multi-channel seismic data acquired during M113 cruise of R/V Meteor in 2014/2015 we discuss the structural evolution of the TR and address the question whether the divergence between both plates is entirely accommodated by the TR. The central TR between São Miguel and Terceira, also known as Hirondelle Basin, is up to 70 km wide. Rifting created two asymmetric graben sections separated by a rift parallel horst. The north-eastern and south-western graben sections are ca. 4 km and 3 km deep, respectively, and the corresponding graben floors are tilted towards the central horst. Volcanic cones emerged on the central horst and rift shoulders. Bright spots in the basin fill deposits indicate fluid flow out of the volcanic basement. The seafloor is displaced by faults which suggest recent fault displacement. In the Eastern Graciosa Basin between Terceira and Graciosa Islands the rift narrows to ca. 40 km and shallows to ca. 3200 m water depth. The central horst is no longer detectable. Instead, a buried normal fault and a small escarpment are observed. Shallow faults and block rotation are less pronounced compared to the basins to the south-east and north-west. The Western Graciosa Basin is about 30 km wide and ca

  18. The MOZART Project - MOZAmbique Rift Tomography (United States)

    Fonseca, J. F.; Chamussa, J. R.; Domingues, A.; Helffrich, G. R.; Fishwick, S.; Ferreira, A. M.; Custodio, S.; Brisbourne, A. M.; Grobbelaar, M.


    Project MOZART (MOZAmbique Rift Tomography) is an ongoing joint effort of Portuguese, Mozambican and British research groups to investigate the geological structure and current tectonic activity of the southernmost tip of the East African Rift System (EARS) through the deployment of a network of 30 broad band seismic stations in Central and Southern Mozambique. In contrast with other stretches of the EARS to the North and with the Kapvaal craton to the West and South, the lithosphere of Mozambique was not previously studied with a dense seismographic deployment on account of past political instability, and many questions remain unanswered with respect to the location and characteristics of the EARS to the south of Tanzania. In recent years, space geodesy revealed the existence of three microplates in and off Mozambique - Victoria, Rovuma, Lwandle - whose borders provide a connection of the EARS to the South West Indian Ridge as required by plate tectonics. However, the picture is still coarse concerning the location of the rift structures. The 2006 M7 Machaze earthquake in Central Mozambique highlighted the current tectonic activity of the region and added a further clue to the location of the continental rift, prompting the MOZART deployment. Besides helping unravel the current tectonics, the project is expected to shed light on the poorly known Mesoproterozoic structure described by Arthur Holmes in 1951 as the Mozambique Belt, and on the mechanisms of transition from stable craton to rifted continental crust, through the development of a tomographic model for the lithosphere. The MOZART network is distributed South of the Zambezi river at average inter-station spaces of the order of 100 km and includes four stations across the border in South Africa. Data exchange was agreed with AfricaArray. The deployment proceeded in two phases in March 2011, and November and December 2011. Decommissioning is foreseen for August 2013. We report preliminary results for this

  19. Initial rifting and long-term landscape evolution of the Albertine Rift in East Africa (United States)

    Bauer, F. U.; Glasmacher, U. A.; Ring, U.; Starz, M.; Grobe, R. W.; Mambo, V. S.


    In East Africa, the feedback between tectonic uplift, erosional denudation and associated possible climate changes is being studied by a multidisciplinary research group, 'RiftLink'. The group's focus is the Albertine Rift of the East African Rift System (EARS), and therein rising Rwenzori Mountains that stretch along the border of the D.R. Congo (DRC) and Uganda. Major questions relate to temporal and spatial evolution of the Rwenzori Mountains and surrounding Albertine Rift: is the surface uplift of the Rwenzoris (>5 km) directly linked to rift movements in Neogene times, or was there a topographic high long before [1]. To understand the morphological evolution of an area or landscape, knowledge about phases of (dis-)equilibrium between rock exhumation and rock uplift governed by climatic and tectonic processes is essential. Low-temperature thermochronology, like fission-track and (U-Th-Sm)/He dating on apatite and zircon (AFT, AHe, ZHe) are well established tools to trace rock displacements through the upper crust. And, therefore, provide fundamental information helping to decipher the long-term landscape evolution of an area. Thermokinematic modelling, applied to samples from different parts of the working area allow to better constrain the cooling history and landscape evolution of the Rwenzori Mts as well as surrounding Albertine Rift which will be discussed in the frame of this presentation. Samples taken along and across the Albertine Rift, cover the area around the Rwenzori Mts and the mountain range itself. From thermochronological analyses (AFT, AHe & ZHe) and subsequent thermal modelling a protracted cooling history since Palaeozoic times can be revealed. This allows tracing back the thermal evolution of this area, long before initiation of the EARS, with the latter showing only minor effects on the cooling of the samples. Striking is the distinct cooling pattern within the Rwenzori Mts, where different blocks can be distinguished revealing

  20. Contrasted continental rifting via plume-craton interaction: Applications to Central East African Rift

    Directory of Open Access Journals (Sweden)

    Alexander Koptev


    Full Text Available The East African Rift system (EARS provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides of the old thick Tanzanian craton embedded in a younger lithosphere. Data on the pre-rift, syn-rift and post-rift far-field volcanic and tectonic activity show that the EARS formed in the context of the interaction between a deep mantle plume and a horizontally and vertically heterogeneous lithosphere under far-field tectonic extension. We bring quantitative insights into this evolution by implementing high-resolution 3D thermo-mechanical numerical deformation models of a lithosphere of realistic rheology. The models focus on the central part of the EARS. We explore scenarios of plume-lithosphere interaction with plumes of various size and initial position rising beneath a tectonically pre-stretched lithosphere. We test the impact of the inherited rheological discontinuities (suture zones along the craton borders, of the rheological structure, of lithosphere plate thickness variations, and of physical and mechanical contrasts between the craton and the embedding lithosphere. Our experiments indicate that the ascending plume material is deflected by the cratonic keel and preferentially channeled along one of its sides, leading to the formation of a large rift zone along the eastern side of the craton, with significant magmatic activity and substantial melt amount derived from the mantle plume material. We show that the observed asymmetry of the central EARS, with coeval amagmatic (western and magmatic (eastern branches, can be explained by the splitting of warm material rising from a broad plume head whose initial position is slightly shifted to the eastern side of the craton. In that case, neither a mechanical weakness of the contact between the craton and the embedding lithosphere nor the presence of second plume are required to

  1. Style of rifting and the stages of Pangea breakup (United States)

    Frizon de Lamotte, Dominique; Fourdan, Brendan; Leleu, Sophie; Leparmentier, François; de Clarens, Philippe


    Pangea results from the progressive amalgamation of continental blocks achieved at 320 Ma. Assuming that the ancient concept of "active" versus "passive" rifting remains pertinent as end-members of more complex processes, we show that the progressive Pangea breakup occurred through a succession of rifting episodes characterized by different tectonic evolutions. A first episode of passive continental rifting during the Upper Carboniferous and Permian led to the formation of the Neo-Tethys Ocean. Then at the beginning of Triassic times, two short episodes of active rifting associated to the Siberian and Emeishan large igneous provinces (LIPs) failed. The true disintegration of Pangea resulted from (1) a Triassic passive rifting leading to the emplacement of the central Atlantic magmatic province (200 Ma) LIP and the subsequent opening of the central Atlantic Ocean during the lowermost Jurassic and from (2) a Lower Jurassic active rifting triggered by the Karoo-Ferrar LIP (183 Ma), which led to the opening of the West Indian Ocean. The same sequence of passive then active rifting is observed during the Lower Cretaceous with, in between, the Parana-Etendeka LIP at 135 Ma. We show that the relationships between the style of rifts and their breakdown or with the type of resulting margins (as magma poor or magma dominated) are not straightforward. Finally, we discuss the respective role of mantle global warming promoted by continental agglomeration and mantle plumes in the weakening of the continental lithosphere and their roles as rifting triggers.

  2. Seismicity of the Earth 1900-2013 East African Rift (United States)

    Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio; Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio


    The East African Rift system (EARS) is a 3,000-km-long Cenozoic age continental rift extending from the Afar triple junction, between the horn of Africa and the Middle East, to western Mozambique. Sectors of active extension occur from the Indian Ocean, west to Botswana and the Democratic Republic of the Congo (DRC). It is the only rift system in the world that is active on a continent-wide scale, providing geologists with a view of how continental rifts develop over time into oceanic spreading centers like the Mid-Atlantic Ridge.

  3. The NE Rift of Tenerife: towards a model on the origin and evolution of ocean island rift


    Delcamp, A.; Troll, V.; S. Wiesmaier; R. Paris; Rodríguez González, A.; Pérez-Torrado, F. J.; Rodríguez Badiola, E.; Guillou, H.; Carracedo, J.C; Fernández-Turiel, J.L. (José Luis)


    The NE Rift of Tenerife is an excellent example of a persistent, recurrent rift, providing important evidence of the origin and dynamics of these major volcanic features. The rift developed in three successive, intense and relatively short eruptive stages (a few hundred ka), separated by longer periods of quiescence or reduced activity: A Miocene stage (7266 ± 156 ka), apparently extending the central Miocene shield of Tenerife towards the Anaga massif; an Upper Pliocene stage (2710 ± 58 ka) ...

  4. Pension Systems in Europe. Case of Greece

    Directory of Open Access Journals (Sweden)

    Jarosław Poteraj


    Full Text Available The article presents an insight into the old age pension system in Greece. The introduction is followed by four topic paragraphs: 1. the general information about the country, 2. the historical development of its pension system, 3. the present situation, and 4. challenges and foreseen changes. There, the authorís goal was to present both past and present solutions employed by the Greeceís pension system, in search for ideas worth consideration in international comparisons. In the summary, the author highlights as a particular Greek approach, on the background of other countries, the fact of existing in the Greek reality The National Actuary.

  5. Recent records of hypogeous fungi in Greece

    Directory of Open Access Journals (Sweden)

    Stephanos Diamandis


    Full Text Available Uncertainty among Greek farmers who are in search of new and profitable crops has increased interest in truffle cultivation. Recent research has come up with 23 taxa of hypogeous fungi new for Greece including gastronomically valuable species. Natural ecosystems of Quercus pubescens, Q. frainetto, Q. ilex and Q. coccifera seem to be rich in hypogeous species. Ecosystems with Corylus avellana, Carpinus betulus, Mediterranean pines and even poplar plantations were found to also host hypogeous fungi. These records, supported by historical information about the existence of truffles in Greece, seem to be encouraging hints for systematic truffle cultivation.

  6. Phanerozoic Rifting Phases And Mineral Deposits (United States)

    Hassaan, Mahmoud


    In North Africa occur Mediterranean and Red Sea metallogenic provinces. In each province distribute 47 iron- manganese- barite and lead-zinc deposits with tectonic-structural control. The author presents in this paper aspects of position of these deposits in the two provinces with Phanerozoic rifting . The Mediterranean Province belongs to two epochs, Hercynian and Alpine. The Hercynian Epoch manganese deposits in only Moroccoa- Algeria belong to Paleozoic tectonic zones and Proterozoic volcanics. The Alpine Epoch iron-manganese deposits are of post-orogenic exhalative-sedimentary origin. Manganese deposits in southern Morocco occur in Kabil-Rief quartz-chalcedony veins controlled by faults in andesitic sheets and in bedded pelitic tuffs, strata-form lenses and ore veins, in Precambrian schist and in Triassic and Cretaceous dolomites. Disseminated manganese with quartz and barite and effusive hydrothermal veins are hosted in Paleocene volcanics. Manganese deposits in Algeria are limited and unrecorded in Tunisia. Strata-form iron deposits in Atlas Heights are widespread in sub-rift zone among Jurassic sediments inter-bedding volcanic rocks. In Algeria, Group Beni-Saf iron deposits are localized along the Mediterranean coast in terrigenous and carbonate rocks of Jurassic, Cretaceous and Eocene age within faults and bedding planes. In Morocco strata-form hydrothermal lead-zinc deposits occur in contact zone of Tertiary andesite inter-bedding Cambrian shale, Lias dolomites and Eocene andesite. In both Algeria and Tunisia metasomatic Pb-Zn veins occur in Campanian - Maastrichtian carbonates, Triassic breccia, Jurassic limestone, Paleocene sandstones and limestone and Neogene conglomerates and sandstones. The Red Sea metallogenic province belongs to the Late Tertiary-Miocene times. In Wadi Araba hydrothermal iron-manganese deposits occur in Cretaceous sediments within 320°and 310 NW faults related to Tertiary basalt. Um-Bogma iron-manganese deposits are closely

  7. af ar rift: discovery of a metallogenic province

    African Journals Online (AJOL)

    Rift Valley has caused hydrothermal activity, which is still active in several sites being investigated for geothermal energy. Extinct geothermal fields are also quite common. The possibility that these geothermal systems, related to the continental rifting, have been and may be ore-forming systems cannot be discarded a priori.

  8. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014 (United States)

    Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J.A.W.; Venter, Estelle H.


    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa. PMID:27869589

  9. Lower crustal intrusions beneath the southern Baikal Rift Zone

    DEFF Research Database (Denmark)

    Nielsen, Christoffer; Thybo, Hans


    The Cenozoic Baikal Rift Zone (BRZ) is situated in south-central Siberia in the suture between the Precambrian Siberian Platform and the Amurian plate. This more than 2000-km long rift zone is composed of several individual basement depressions and half-grabens with the deep Lake Baikal at its ce...

  10. Lithosphere Response to Intracratonic Rifting: Examples from Europe and Siberia

    DEFF Research Database (Denmark)

    Artemieva, I. M.; Thybo, H.; Herceg, M.


    of basaltic magmas and consequently in a change in mantle density and seismic velocities. Although kimberlite magmatism is commonly not considered as a rifting events, its deep causes may be similar to the mantle-driven rifting and, as a consequence, modification of mantle density and velocity structure may...


    African Journals Online (AJOL)


    ABSTRACT. The Tanzanian rift system salt lakes present significant cultural, ecological, recreational and economical values. Beyond the wealth of minerals, resources of these rift salt lakes include unique wildlife, for instance Lesser Flamingo (Phoenicopterus minor) and Cichlids (Alcolapia spp), which adapted chemically ...

  12. Structural evolution of the Kilombero rift basin in central Tanzania ...

    African Journals Online (AJOL)

    Detailed geological and structural investigations at the northwestern scarp of the Cenozoic Kilombero Rift allow the drawing of its structural evolution and establishment of stress conditions that prevailed at the different deformational episodes at this rift zone. The structure, where the northwestern scarp of the Cenozoic ...

  13. Combining detrital geochronology and sedimentology to assess basin development in the Rukwa Rift of the East African Rift System (United States)

    Hilbert-Wolf, Hannah; Roberts, Eric; Mtelela, Cassy; Downie, Bob


    We have employed a multifaceted approach to sedimentary provenance analysis in order to assess the timing and magnitude of tectonic events, sedimentation, and landscape development in the Western Branch of the East African Rift System. Our approach, termed 'Sedimentary Triple Dating', integrates: (1) U-Pb dating via LA-ICPMS; (2) fission track; and (3) (U-Th)/He thermochronology of detrital zircon and apatite. We integrate geochronology, thermochronology, and provenance analysis to relate the initiation of rifting events to regional dynamic uplift, sedimentation patterns, and interpret the far-reaching climatic and evolutionary effects of fluctuating rift flank topography in the Rukwa Rift, a segment of the Western Branch. This work provides additional data to support the recent concept of synchronous development of the Western and Eastern branches of the East African Rift System ~25 Ma, and better constrains the age, location and provenance of subsequent rifting and sedimentation events in the Rukwa Rift Basin. Investigation of well cuttings and outcrop samples from the Neogene-Recent Lake Beds Succession in the Rukwa Rift Basin revealed a suite of previously unrecognized tuffaceous deposits at the base of the succession. A population of euhedral, magmatic zircons from a basal Lake Beds tuff and Miocene-Pliocene detrital zircons from well cuttings suggest that Neogene rift reactivation and volcanism began ~9-10 Ma. This timing is consistent with demonstrated rifting in Uganda and Malawi, as well as with the initiation of volcanism in the Rungwe Volcanic Province at the southern end of the Rukwa Rift, and the estimated development of Lake Tanganyika to the north. Moreover, there appear to be a suite of unconformity bounded stratigraphic units that make up the Lower Lake Beds succession, and detrital zircon maximum depositional ages from these units suggests episodic sedimentation in the rift, punctuated by long hiatuses or uplift, rather than steady subsidence and

  14. Academic libraries in Greece: a new perspective


    Raptis, Paschalis; Sitas, Anestis


    The current status of the academic libraries in Greece is examined. A brief summary of each academic institution and its library is given. Collection development, staff, and the bibliographic organization of the materials are described. The bibliographic standards that libraries apply, automation and retrospective conversion are presented. General assessments, short presentation of automation systems and areas for development are also provided.

  15. The Demand for Higher Education in Greece (United States)

    Saiti, Anna; Prokopiadou, Georgia


    This paper focuses on the reasons for enrolment demand in higher education in Greece through data collected from 400 students enrolled in the final year of post-secondary education in the Athens area. Results showed that Greek students choose to follow higher studies for a number of reasons but mainly because higher education offers high-level…

  16. Additional records of Actiniaria (Anthozoa) from Greece

    NARCIS (Netherlands)

    Chintiroglou, Ch.; Hartog, den J.C.


    A small collection of four species of Actiniaria, partly representing new records for Greece and the eastern Mediterranean, is described and discussed. These four species are: Bunodeopsis strumosa Andres, 1881, Edwardsia claparedii (Panceri, 1869), Actinia cari delle Chiaje, 1825, and Phymanthus

  17. The Preparation of School Psychologists in Greece (United States)

    Hatzichristou, Chryse; Polychroni, Fotini


    The paper describes the preparation of school psychologists in Greece. It discusses the social and cultural contexts that have influenced the evolution of the discipline of psychology, the beginning of training programs in school psychology, and the current status of school psychological services. The structure of the Graduate Program of School…

  18. New insights into continental rifting from a damage rheology modeling (United States)

    Lyakhovsky, Vladimir; Segev, Amit; Weinberger, Ram; Schattner, Uri


    Previous studies have discussed how tectonic processes could produce relative tension to initiate and propagate rift zones and estimated the magnitude of the rift-driving forces. Both analytic and semi-analytic models as well as numerical simulations assume that the tectonic force required to initiate rifting is available. However, Buck (2004, 2006) estimated the minimum tectonic force to allow passive rifting and concluded that the available forces are probably not large enough for rifting of thick and strong lithosphere in the absence of basaltic magmatism (the "Tectonic Force" Paradox). The integral of the yielding stress needed for rifting over the thickness of the normal or thicker continental lithosphere are well above the available tectonic forces and tectonic rifting cannot happen (Buck, 2006). This conclusion is based on the assumption that the tectonic stress has to overcome simultaneously the yielding stress over the whole lithosphere thickness and ignore gradual weakening of the brittle rocks under long-term loading. In this study we demonstrate that the rifting process under moderate tectonic stretching is feasible due to gradual weakening and "long-term memory" of the heavily fractured brittle rocks, which makes it significantly weaker than the surrounding intact rock. This process provides a possible solution for the tectonic force paradox. We address these questions utilizing 3-D lithosphere-scale numerical simulations of the plate motion and faulting process base on the damage mechanics. The 3-D modeled volume consists of three main lithospheric layers: an upper layer of weak sediments, middle layer of crystalline crust and lower layer of the lithosphere mantle. Results of the modeling demonstrate gradual formation of the rift zone in the continental lithosphere with the flat layered structure. Successive formation of the rift system and associated seismicity pattern strongly depend not only on the applied tectonic force, but also on the healing

  19. Integrated palaeoenvironmental reconstruction of a Lower Pleistocene section (Sousaki basin, Northeastern Corinth Gulf): using fuzzy logic to decipher long term palaeoenvironmental changes. (United States)

    Papadopoulou, Pinelopi; Iliopoulos, George; Koukouvelas, Ioannis; Rentoumi, Evaggelia; Groumpos, Peter


    Palaeoecological analyses are important tools for the reconstruction of palaeoenvironmental changes. In this paper microfossil assemblages (ostracodes and palynomorphs) of Lower Pleistocene age, are used to reconstruct the biological and physical conditions of the palaeoenvironment during a time interval when palaeoclimatic and palaeoecological data from the Balkan Peninsula are scarce. Lower Pleistocene is an epoch when major changes in the palaeoclimate occurred (commencement of the Quaternary glaciations) affecting the palaeoenvironments worldwide. The studied section, geotectonically belongs to the Northeastern Corinth gulf, and lies near the town Ag. Theodoroi, west of Athens, consisting of alterations of marls and marly limestones with intercalations of organic rich sediments and gypsum beds. Detailed logging of the section was carried out and 76 samples were collected for micropalaeontological analysis. Additionally, 22 samples were studied for their palynological content. The results were statistically processed using standard palaeoecological methods (percentage abundance diagrams, biodiversity indices and multivariate analysis). Our interpretation was further supported by fuzzy logic methods, in order to remove subjectivity from the biostratigraphical data providing a higher degree of detail. Despite this though, their use in geology remains limited until now. In our case study, fuzzy sets examine the data from a more general perspective and contain natural variations that are present in species abundance gradients between evolving environments. The lithological and micropalaeontological analysis revealed a brackish lagoonal environment dominated by the typical brackish ostracode species Cyprideis torosa. The studied sequence shows cyclically changing subenvironments fluctuating from the outer to the inner zone of a lagoon as imposed by the alternating occurrence of the ostracode families Tyrrhenocytheridae and Candonidae and the foraminifera species A

  20. Groundwater fluoride enrichment in an active rift setting: Central Kenya Rift case study

    Energy Technology Data Exchange (ETDEWEB)

    Olaka, Lydia A., E-mail: [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Wilke, Franziska D.H. [Geoforschungs Zentrum, Telegrafenberg, 14473 Potsdam (Germany); Olago, Daniel O.; Odada, Eric O. [Department of Geology, University of Nairobi, P.O Box 30197, Nairobi (Kenya); Mulch, Andreas [Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt (Germany); Institut für Geowissenschaften, Goethe Universität Frankfurt, Altenhöferallee 1, 60438 Frankfurt (Germany); Musolff, Andreas [UFZ-Helmholtz-Centre for Environmental Research, Department of Hydrogeology, Permoserstr. 15, 04318 Leipzig (Germany)


    Groundwater is used extensively in the Central Kenya Rift for domestic and agricultural demands. In these active rift settings groundwater can exhibit high fluoride levels. In order to address water security and reduce human exposure to high fluoride in drinking water, knowledge of the source and geochemical processes of enrichment are required. A study was therefore carried out within the Naivasha catchment (Kenya) to understand the genesis, enrichment and seasonal variations of fluoride in the groundwater. Rocks, rain, surface and groundwater sources were sampled for hydrogeochemical and isotopic investigations, the data was statistically and geospatially analyzed. Water sources have variable fluoride concentrations between 0.02–75 mg/L. 73% exceed the health limit (1.5 mg/L) in both dry and wet seasons. F{sup −} concentrations in rivers are lower (0.2–9.2 mg/L) than groundwater (0.09 to 43.6 mg/L) while saline lake waters have the highest concentrations (0.27–75 mg/L). The higher values are confined to elevations below 2000 masl. Oxygen (δ{sup 18}O) and hydrogen (δD) isotopic values range from − 6.2 to + 5.8‰ and − 31.3 to + 33.3‰, respectively, they are also highly variable in the rift floor where they attain maximum values. Fluoride base levels in the precursor vitreous volcanic rocks are higher (between 3750–6000 ppm) in minerals such as cordierite and muscovite while secondary minerals like illite and kaolinite have lower remnant fluoride (< 1000 ppm). Thus, geochemical F{sup −} enrichment in regional groundwater is mainly due to a) rock alteration, i.e. through long residence times and natural discharge and/or enhanced leakages of deep seated geothermal water reservoirs, b) secondary concentration fortification of natural reservoirs through evaporation, through reduced recharge and/or enhanced abstraction and c) through additional enrichment of fluoride after volcanic emissions. The findings are useful to help improve water management

  1. A Blowing Snow Model for Ice Shelf Rifts (United States)

    Leonard, K. C.; Tremblay, L.; Macayeal, D. R.


    Ice melange (a mixture of snow, marine ice, and ice talus) may play various roles in the rates of propagation of iceberg-calving rifts through Antarctic ice shelves. This modeling study examines the role of windblown snow in the formation and maintenance of ice melange in the "nascent rift" in the Ross Ice Shelf (78 08'S, 178 29'W). The rift axis is perpendicular to the regional wind direction, allowing us to employ a two-dimensional blowing snow model. The Piektuk-Tuvaq blowing snow model (Dery and Tremblay, 2004) adapted the Piektuk blowing snow model for use in sea ice environments by including parameterization for open-water leads within the sea ice. This version of the model was used to study the initial conditions of a freshly-opened rift, as the input of blowing snow into the seawater within the rift promotes marine ice formation by cooling and freshening the surface water. We adapted the Piektuk-Tuvaq model both for the local climatic conditions and to incorporate the geometry of the rift, which is 30m deep and 100m wide (far deeper than a lead). We present the evolution of the topography within the rift for two cases. The first is an ice melange composed exclusively of snow and marine ice, the second uses an initial topography including large chunks of ice talus.

  2. Facies, stratal and stacking patterns of syn-rift sequences along present-day and fossil hyperextended rifted margins (United States)

    Ribes, Charlotte; Epin, Marie-Eva; Gillard, Morgane; Chenin, Pauline; Ghienne, Jean-Francois; Manatschal, Gianreto; Karner, Garry D.; Johnson, Christopher A.


    Research on the formation and evolution of deep-water rifted margins has undergone a major paradigm shift in recent years. An increasing number of studies of present-day and fossil rifted margins allows us to identify and characterize the architecture of hyperextended rifted margins. However, at present, little is known about the depositional environments, sedimentary facies and stacking and stratal patterns in syn-rift sequences within these domains. In this context, characterizing and understanding the spatial and temporal evolution of the stratal and stacking patterns is a new challenge. The syn-rift sequence at rifted margins is deposited during the initial stages of stretching to the onset of oceanic accretion and comprises pre-, syn- and post-kinematic deposits along the margin. A difficulty arises from the fact that the observed stratigraphic geometries and facies relationships result from the complex interplay between sediment supply and creation of accommodation, which in turn are controlled by regional synchronous events (i.e. crustal necking and onset of seafloor spreading) and diachronous events (i.e. migration of deformation during rifting, lags in sediment input to the distal margin). These parameters are poorly constrained in hyperextended rift systems. Indeed, the complex structural evolution of hyperextended systems include an evolution from initially distributed to localized extension (i.e. necking) and the development of poly-phase in-sequence and/or out of sequence extensional faulting associated with mantle exhumation and magmatic activity. This multiphase structural evolution can generate complex accommodation patterns over a highly structured top basement but can only be recognized if there is sufficient sediment input to record the events. In our presentation, we show preliminary results for fossil Alpine Tethys margins exposed in the Alps and seismic examples of the present-day deep water rifted margins offshore Australian-Antarctica, East

  3. Deep seismic sounding in the Turkana depression, northern Kenya Rift (United States)

    Gajewski, Dirk; Schulte, Andreas; Riaroh, Don; Thybo, Hans


    Existing models of the structure and evolution of the Kenya Rift such as pure shear lithospheric extension, extension by simple shear or rift development by diapiric upwelling of an asthenolith, were based upon surface geology and a few geophysical (mainly gravity and seismic) data sets. Since the knowledge of the lithospheric structure plays an important role to distinguish between these different models, the Kenya Rift International Seismic Project was conducted in 1990 in the area of the Kenya Rift. The project involved a detailed multi-fold refraction wide-angle reflection line in the northern Kenya Rift along the western shore of Lake Turkana which is the most prominent feature of the so-called Turkana depression. Under-water explosions were used as sources and a good signal-to-noise ratio was obtained allowing the identification of arrivals from the crust and upper mantle. The most important result of modelling the data is a crustal thickness of 21 km in the area of Lake Turkana, whereas in the area of the Kenya dome the crustal thickness is 34 km. This points to an extension not previously expected in the northern Kenya Rift. The Moho discontinuity appears as a transition zone in the northern part of the profile, whereas in the southern part it changes to a first-order discontinuity. The largest vertical and lateral heterogeneities are observed in the rift infill displaying basins of varying thickness. The upper and lower crust which are separated by the Conrad discontinuity (the velocity changes from 6.2 to 6.4 km/s here) show very little lateral heterogeneity. The P-wave velocity in the upper mantle was modelled to be 7.7 km/s and thus can be distinguished from that in the southern Kenya Rift, where a velocity of 7.5 km/s was observed. The crustal structure of the graben supports a model of a southerly propagation of the rift.

  4. An epidemiological model of Rift Valley fever

    Directory of Open Access Journals (Sweden)

    Nicole P. Leahy


    Full Text Available We present and explore a novel mathematical model of the epidemiology of Rift Valley Fever (RVF. RVF is an Old World, mosquito-borne disease affecting both livestock and humans. The model is an ordinary differential equation model for two populations of mosquito species, those that can transmit vertically and those that cannot, and for one livestock population. We analyze the model to find the stability of the disease-free equlibrium and test which model parameters affect this stability most significantly. This model is the basis for future research into the predication of future outbreaks in the Old World and the assessment of the threat of introduction into the New World.

  5. Rift Valley Fever, Sudan, 2007 and 2010 (United States)

    Aradaib, Imadeldin E.; Erickson, Bobbie R.; Elageb, Rehab M.; Khristova, Marina L.; Carroll, Serena A.; Elkhidir, Isam M.; Karsany, Mubarak E.; Karrar, AbdelRahim E.; Elbashir, Mustafa I.


    To elucidate whether Rift Valley fever virus (RVFV) diversity in Sudan resulted from multiple introductions or from acquired changes over time from 1 introduction event, we generated complete genome sequences from RVFV strains detected during the 2007 and 2010 outbreaks. Phylogenetic analyses of small, medium, and large RNA segment sequences indicated several genetic RVFV variants were circulating in Sudan, which all grouped into Kenya-1 or Kenya-2 sublineages from the 2006–2008 eastern Africa epizootic. Bayesian analysis of sequence differences estimated that diversity among the 2007 and 2010 Sudan RVFV variants shared a most recent common ancestor circa 1996. The data suggest multiple introductions of RVFV into Sudan as part of sweeping epizootics from eastern Africa. The sequences indicate recent movement of RVFV and support the need for surveillance to recognize when and where RVFV circulates between epidemics, which can make data from prediction tools easier to interpret and preventive measures easier to direct toward high-risk areas. PMID:23347790

  6. Simulation of macroseismic field in Central Greece

    Directory of Open Access Journals (Sweden)

    J. Drakopoulos


    Full Text Available The distribution of seismic intensity is generally influenced by major geological and tectonic features and, on a smaller scale, by local geological conditions, such as the type of surface soil, the surface-to-bedrock soil structure in sedimentary basins and the depth of the saturated zone, The present paper attempted to determine the distribution of macroseismic intensities based on published attenuation laws in the area of Central Greece, using the epicentral intensity, magnitude, length and direction of fault and a considerable number of observation sites, for which the above mentioned information is available, The expected intensity values were then compared to those observed in the same sites, from four earthquakes in Volos, Central Greece, for which the fault plane solutions are also known. The deviations of the observed values from the theoretical model were then related to the local geological conditions and the corresponding correction factor determined for each site.

  7. Youth unemployment in Greece: Measuring the challenge


    Bell, David N.F.; Blanchflower, David G.


    A historically high level of youth unemployment presents Greece with a huge social and economic challenge. This paper analyses various dimensions of this challenge. We argue that though the conventional definition of "youth" is the 16-24 age group, there is a strong case for considering 25 to 29-year-olds as sharing common problems with conventionally defined youth. There are also grounds for examining why females seem to fare worse than males in the Greek labour market. The negative effects ...

  8. Low lower crustal velocity across Ethiopia: Is the Main Ethiopian Rift a narrow rift in a hot craton? (United States)

    Keranen, K.M.; Klemperer, S.L.; Julia, J.; Lawrence, J. F.; Nyblade, A.A.


    [1] The Main Ethiopian Rift (MER) is a classic narrow rift that developed in hot, weak lithosphere, not in the initially cold, thick, and strong lithosphere that would be predicted by common models of rift mode formation. Our new 1-D seismic velocity profiles from Rayleigh wave/receiver function joint inversion across the MER and the Ethiopian Plateau indicate that hot lower crust and upper mantle are present throughout the broad region affected by Oligocene flood basalt volcanism, including both the present rift and the adjacent Ethiopian Plateau hundreds of kilometers from the rift valley. The region of hot lithosphere closely corresponds to the region of flood basalt volcanism, and we interpret that the volcanism and thermal perturbation were jointly caused by impingement of the Afar plume head. Across the affected region, Vs is 3.6-3.8 km/s in the lowermost crust and ???4.3 km/s in the uppermost mantle, both ??0.3 km/s lower than in the eastern and western branches of the East African Rift System to the south. We interpret the low Vs in the lower crust and upper mantle as indicative of hot lithosphere with partial melt. Our results lead to a hybrid rift mode, in which the brittle upper crust has developed as a narrow rift along the Neoproterozoic suture between East and West Gondwana, while at depth lithospheric deformation is distributed over the broad region (??400 km wide) thermally perturbed by the broad thermal upwelling associated with the Afar plume head. Development of both the East African Rift System to the south (in cold, strong lithosphere) and the MER to the north (in hot, weak lithosphere) as narrow rifts, despite their vastly different initial thermal states and depth-integrated lithospheric strength, indicates that common models of rift mode formation that focus only on temperature, thickness, and vertical strength profiles do not apply to these classic continental rifts. Instead, inherited structure and associated lithospheric weaknesses are

  9. Electrifying Greece with solar and wind energy

    Directory of Open Access Journals (Sweden)

    Mentis Dimitris


    Full Text Available Ensuring energy security, reducing GHG emissions and boosting the competitiveness of a country’s economy by attracting investments and technical knowhow are of paramount importance considering the targets of “20-20-20” set by the European community. Being the cradle of civilization, Greece appears today as a country caught in a prolonged hard economic and social crisis, the way out of which its citizens are looking forward as well as the entire European Union. Establishment of the leading renewable energy sources like solar and wind in Greece will not only increase the independence of its own electrification but will also provide with a foundation for developing the market of international trade of “green” energy. This paper initially highlights the current status of photovoltaics and wind turbines in Greece. Furthermore, this study evaluates whether a higher penetration of the above mentioned green energy sources would have positive impact in the economy of the country or not and in what extent they could decline the CO2 emissions until 2020, comparing to the corresponding levels in 2010.

  10. The precursory earthquake swarm in Greece

    Directory of Open Access Journals (Sweden)

    D. Rhoades


    Full Text Available The Hellenic subduction region displays the same precursory swarm phenomenon as has been found in comparable regions of New Zealand and Japan. In the earthquake catalogue of the Aristotle University of Thessaloniki, 10 past sequences of precursory swarms and related major mainshock events have been identified. These correlate, in respect of location, magnitude and time, with the 9 sequences previously identified in New Zealand, and 9 in Japan, bringing the total of sequences to 28, and the totals of related events (allowing for clustering to 56 precursory swarms and 42 mainshock events. The results add strength to the hypothesis that swarms are long-range predictors of mainshock events. A close similarity between the swarm and aftershock magnitudes in a given sequence is also confirmed in Greece, supporting the proposal that swarms are an integral part of the seismogenic process in subduction regions. Further, the modelling of swarms as part of an overall increase in seismicity, the onset of which marks the onset of seismogenesis, is well illustrated from past sequences in Greece. Formal tests are being carried out in Greece, in parallel with New Zealand and Japan, to ascertain the performance of the hypothesis as a basis for long-range synoptic forecasting.

  11. Medical Informatics Education & Research in Greece. (United States)

    Chouvarda, I; Maglaveras, N


    This paper aims to present an overview of the medical informatics landscape in Greece, to describe the Greek ehealth background and to highlight the main education and research axes in medical informatics, along with activities, achievements and pitfalls. With respect to research and education, formal and informal sources were investigated and information was collected and presented in a qualitative manner, including also quantitative indicators when possible. Greece has adopted and applied medical informatics education in various ways, including undergraduate courses in health sciences schools as well as multidisciplinary postgraduate courses. There is a continuous research effort, and large participation in EU-wide initiatives, in all the spectrum of medical informatics research, with notable scientific contributions, although technology maturation is not without barriers. Wide-scale deployment of eHealth is anticipated in the healthcare system in the near future. While ePrescription deployment has been an important step, ICT for integrated care and telehealth have a lot of room for further deployment. Greece is a valuable contributor in the European medical informatics arena, and has the potential to offer more as long as the barriers of research and innovation fragmentation are addressed and alleviated.

  12. Novel phleboviruses detected in ticks, Greece. (United States)

    Papa, Anna; Kontana, Anastasia; Tsioka, Katerina; Chaligiannis, Ilias; Sotiraki, Smaragda


    Since 2009, when severe fever with thrombocytopenia syndrome virus and Heartland virus have been identified and associated with disease in humans, the interest on tick-borne phleboviruses is increasing rapidly. The aim of the present study was to investigate the presence of tick-borne phleboviruses in Greece and compare them with respective ones detected worldwide. Ticks collected from goats and sheep in 60 sites of 13 regional units of Greece were grouped in pools (1-3 ticks per pool) and tested for the presence of phleboviral RNA. Six of 210 pools were positive; they consisted of Rhipicephalus sanguineus ticks collected from sheep in 3 regional units of Greece: Pella (2/30, 6.7%), Imathia (2/21, 9.5%), and Ioannina (2/28, 7.1%). The overall tick minimum infection rate was 2.1%. The sequences of the Greek phlebovirus (provisionally named Antigone virus) form a distinct clade in the tick-borne phleboviruses, differing by >40% from the currently known phleboviruses. Any probable implication of these viruses to public health remains to be elucidated. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Amagmatic Lithospheric Rifting as Expressed in the Red Sea (Invited) (United States)

    Cochran, J. R.


    The Red Sea is an active analog for the rifting that produced most of the non-magmatic passive continental margins of the Atlantic and Indian Oceans. Specifically, it cuts through old (Pre-Cambrian) lithosphere well away from other plate boundaries and rifting is within 30° of orthogonal to the trend of the rift. Observations in the Red Sea therefore provide insights that can be applied to older, relict non-magmatic margins Although rifting in the Red Sea has been basically amagmatic, magmatism at two crucial times was important in defining the location of the rift and of initiating active extension and rifting. The onset of rifting was preceded by massive volcanism in Ethiopia and southern Yemen. The major volume of lava was erupted over a short period from 31-29.5 Ma. This event appears to have defined the location of the triple junction between the Red Sea, Gulf of Aden and Ethiopian rifts. Although rifting along the Gulf of Aden may have initiated at the time of the Afar volcanism, this magmatic episode was not accompanied by significant extension in the region that was to become the Red Sea and there is no sign of continuing extension in the Red Sea beginning at that time. The onset of rifting and extension in the Red Sea immediately follows a massive episode of dike intrusion that occurred over a short period of time at 24-21 Ma. Diking extended for 1700 km along the entire length of the Red Sea with no discernable temporal pattern. The diking event coincides with deposition of the first clearly syn-rift sediments at locations from the Gulf of Suez to Eritrea as well as the beginning of uplift and denudation. The diking event may have enabled rifting and extension in the Red Sea. There is no evidence of additional volcanism within the Red Sea rift from 21 Ma to the initiation of seafloor spreading. Seismic reflection and potential field data from the northern Red Sea show that large, rotated fault blocks of continental crust underlie the basin. Rifting is

  14. A Statistical Model of Rift Valley Fever Activity in Egypt

    National Research Council Canada - National Science Library

    John M. Drake; Ali N. Hassan; John C. Beier


    Rift Valley fever (RVF) is a viral disease of animals and humans and a global public health concern due to its ecological plasticity, adaptivity, and potential for spread to countries with a temperate climate...

  15. Metallogeny of the midcontinent rift system of North America (United States)

    Nicholson, S.W.; Cannon, W.F.; Schulz, K.J.


    The 1.1 Ga Midcontinent rift system of North America is one of the world's major continental rifts and hosts a variety of mineral deposits. The rocks and mineral deposits of this 2000 km long rift are exposed only in the Lake Superior region. In the Lake Superior region, the rift cuts across Precambrian basement terranes ranging in age from ??? 1850 Ma to more than 3500 Ma. Where exposed, the rift consists of widespread tholeiitic basalt flows with local interlayered rhyolite and clastic sedimentary rocks. Beneath the center of Lake Superior the volcanic and sedimentary rocks are more than 30 km deep as shown by recent seismic reflection profiles. This region hosts two major classes of mineral deposits, magmatic and hydrothermal. All important mineral production in this region has come from hydrothermal deposits. Rift-related hydrothermal deposits include four main types: (1) native copper deposits in basalts and interflow sediments; (2) sediment-hosted copper sulfide and native copper; (3) copper sulfide veins and lodes hosted by rift-related volcanic and sedimentary rocks; and (4) polymetallic (five-element) veins in the surrounding Archean country rocks. The scarcity of sulfur within the rift rocks resulted in the formation of very large deposits of native metals. Where hydrothermal sulfides occur (i.e., shale-hosted copper sulfides), the source of sulfur was local sedimentary rocks. Magmatic deposits have locally supported exploration and minor production, but most are subeconomic presently. These deposits occur in intrusions exposed near the margins of the rift and include CuNiPGE and TiFe (V) in the Duluth Complex, U-REE-Nb in small carbonatites, and breccia pipes resulting from local hydrothermal activity around small felsic intrusions. Mineralization associated with some magmatic bodies resulted from the concentration of incompatible elements during fractional crystallization. Most of the sulfide deposits in intrusions, however, contain sulfur derived from

  16. Ship emissions and their externalities for Greece (United States)

    Tzannatos, Ernestos


    The existing and emerging international and European policy framework for the reduction of ship exhaust emissions dictates the need to produce reliable national, regional and global inventories in order to monitor emission trends and consequently provide the necessary support for future policy making. Furthermore, the inventories of ship exhaust emissions constitute the basis upon which their external costs are estimated in an attempt to highlight the economic burden they impose upon the society and facilitate the cost-benefit analysis of the proposed emission abatement technologies, operational measures and market-based instruments prior to their implementation. The case of Greece is of particular interest mainly because the dense ship traffic within the Greek seas directly imposes the impact of its exhaust emission pollutants (NO x, SO 2 and PM) upon the highly populated, physically sensitive and culturally precious Greek coastline, as well as upon the land and seas of Greece in general, whereas the contribution of Greece in the global CO 2 inventory at a time of climatic change awareness cannot be ignored. In this context, this paper presents the contribution of Greece in ship exhaust emissions of CO 2, NO x, SO 2 and PM from domestic and international shipping over the last 25 years (1984-2008), utilizing the fuel-based (fuel sales) emission methodology. Furthermore, the ship exhaust emissions generated within the Greek seas and their externalities are estimated for the year 2008, through utilizing the fuel-based (fuel sales) approach for domestic shipping and the activity-based (ship traffic) approach for international shipping. On this basis, it was found that during the 1984 to 2008 period the fuel-based (fuel sales) ship emission inventory for Greece increased at an average annual rate of 2.85%. In 2008, the CO 2, NO x, SO 2 and PM emissions reached 12.9 million tons (of which 12.4 million tons of CO 2) and their externalities were found to be around 3

  17. A Middle-Upper Miocene fluvial-lacustrine rift sequence in the Song Ba Rift, Vietnam

    DEFF Research Database (Denmark)

    Lars H., Nielsen; Henrik I., Petersen; Nguyen D., Dau


    The small Neogene Krong Pa graben is situated within the continental Song Ba Rift, which is bounded by strike-slip faults that were reactivated as extensional faults in Middle Miocene time. The 500 m thick graben-fill shows an overall depositional development reflecting the structural evolution...... development sedimentation rate outpaced the formation of accommodation space and fluvial activity increased again. During periods when the general sedimentation rate was in balance with the creation of accommodation space the environment changed frequently between lake deposition and intermittent vigorous...

  18. Control of rift asymmetry and segmentation on the thermal architecture of hyperextended rift systems: insights from Pyrenean field observations and numerical modelling (United States)

    Lescoutre, Rodolphe; Tugend, Julie; Brune, Sascha; Manatschal, Gianreto


    Mid-Cretaceous rift basins are exposed in the Pyrenees providing key information on rifted domain formation that is not available at present-day rift system. Substantial paleotemperature and thermochronological data have been collected and published in numerous recent papers. These data show a strong heterogeneity in the distribution of peak temperatures within the Cretaceous rift basins. Locations that experienced relatively high or low temperatures appear to cluster in specific areas along strike. These areas have been interpreted as either reflecting hot and cold conditions during rifting, or alternatively, a change in the polarity of a strongly asymmetric rift systems. In this study, we test if the observed variability of peak temperatures can be explained by segmentation and a change in polarity of an asymmetrical upper/lower plate rift model. To this aim we restore the observed syn- to early post-rift peak temperatures to their paleo-location within sections across the evolving rift system. In the meantime, we conduct numerical models of rift migration leading to asymmetrical extension that are benchmarked with geological and geophysical observations from the Pyrenees. From the models, we extract thermal information at different stages of rifting that are finally compared to the thermal data from the Pyrenean Cretaceous rift basins. This work employs a novel approach by comparing thermal output from numerical modelling with the distribution of peak temperatures and thermal gradient from field data. As such, these results may have substantial implications to further understand the pre-orogenic thermal evolution of the Pyrenean rift system and the role of segmentation. More generally, the results of this work may unravel the role of rift asymmetry and segmentation on the thermal architecture of hyperextended rift basins and margins.

  19. Intellectual Assessment of Children and Adolescents: The Case of Greece (United States)

    Bablekou, Zoe; Kazi, Smaragda


    The article reviews the history of intellectual assessment of children and adolescents in Greece, as well as procedures, current practices, and future directions. Although the history of special education is long in Greece, there has been very sporadic and incoherent legislation and decision making on the subject. Currently, intelligence tests are…

  20. Conducting Qualitative Research on Desertification in Western Lesvos, Greece (United States)

    Iosifides, Theodoros; Politidis, Theodoros


    The main aim of this article is to present some critical methodological strategies employed in a qualitative research study on local socioeconomic development and desertification in western Lesvos, Greece. Through in-depth qualitative interviews with local producers in western Lesvos, Greece, an effort was made to identify and analyze the links…

  1. Genotyping Plasmodium vivax isolates from the 2011 outbreak in Greece

    DEFF Research Database (Denmark)

    Spanakos, Gregory; Alifrangis, Michael; Schousboe, Mette L


    Plasmodium vivax malaria was common in Greece until the 1950s with epidemics involving thousands of cases every year. Greece was declared free of malaria by the World Health Organization in 1974. From 1974 to 2010, an average of 39 cases per year were reported, which were mainly imported. However...

  2. Baikal rift basement: structure and tectonic evolution

    Energy Technology Data Exchange (ETDEWEB)

    Melnikov, A.I.; Mazukabzov, A.M.; Sklyarov, E.V.; Vasiljev, E.P. (AN SSSR, Irkutsk (Russian Federation). Sibirskij Ehnergeticheskij Inst.)


    The Baikal rift zone in East Siberia has, due to its very long history, starting in the Early Precambrian and continuing into the Cenozoic, an heterogeneous structure. Two major structural elements are distinguished: the Siberian craton and the Sayan-Baikal fold system, which is part of the Central Asian Fold Belt. Within the craton, the following units are recognized: the Early Precambrian metamorphic rocks of the basement, the Vendian-Paleozoic sedimentary cover with superimposed Paleozoic and Mesozoic basins and a reworked margin which is transitional between the craton and the fold belt. The Sayan-Baikal fold system comprises the Barguzin, Tuva-Mongolian and Dzhida terranes. The Barguzin and Tuva-Mongolian terranes are composite, consisting of separate Early Precambrian massifs, volcanic-sedimentary and carbonate Phanerozoic terranes, impregnated by granites. They are thus super-terranes. The oldest units are ophiolites, dated around 1.1 - 1.3 Gy in the Barguzin terrane and 0.9 - 1.1 Gy in the Tuva-Mongolian terrane. They associate with complexes of immature island-arc accretionary wedges of mainly terrigenous or terrigeno-volcanic composition with occasional slices of ophiolite and glaucophane schists. (authors). 68 refs., 12 figs., 2 tabs.

  3. Distributional effects of environmental policies in Greece (United States)

    Lekakis, Joseph N.


    Environmental protection policies generate an equity question concerning the fair allocation of environmental benefits and costs. This paper presents evidence from Greece during the 1980s. The findings reveal that Greek environmental policies, in the form of government self-regulatory programs, are mostly regressive in nature. At the regional level these programs combine all forms of vertical equity. Since the public sector finances the majority of related expenditures out of taxes, the regressive elements of environmental policies have been reinforced by discretionary fiscal measures and tax evasion, accompanied by inflation, which have distorted the country's progressive tax system.



    Panagiotis ARTELARIS; George KANDYLIS


    Poverty has been a matter of great academic and political concern for decades. In the recent years, the interest has increased considerably at the European Union level because poverty seems to be a relatively persistent phenomenon and a threat to economic prosperity and social cohesion of the Union. The aim of this paper is to assess and map, for the first time, the distribution of poverty at the NUTS III level in Greece, as well as to evaluate and map the regional impact of the ongoing econo...

  5. (ReConsidering American Studies in Greece

    Directory of Open Access Journals (Sweden)

    Zoe Detsi-Diamanti


    Full Text Available In writing about American studies in Greece, one is tempted to consider for a moment the fact that the field, ever since it placed itself on the international academic map, has been in a constant process of self-discovery and self-becoming. Its openness, which may be taken as evidence for its vibrant existence and its ability to reconstruct and deconstruct itself, has led to new areas of research, new formulations, new critiques, as well as to an essential paradox  : although we currently wit...

  6. Plume-rift interaction in the Deccan volcanic province (United States)

    Sheth, H. C.; Chandrasekharam, D.


    It is widely accepted that the grand volcanic episode of the Deccan in India was a consequence of the passage of the northerly drifting Indian subcontinent over the Réunion starting plume in the Late Cretaceous. This plume also produced the three-rift Cambay triple junction, the three arms being the West Coast graben belt, the Narmada-Tapi rift zone and the Cambay rift. Deccan-related alkalic magmatism both preceded and followed the main tholeiitic phase of ˜ 65 Ma ago by about 3 MY. The uniformly tholeiitic thick basalt sequence of the Western Ghats was derived from direct melting of the plume head, but the tholeiitic-alkalic magmatism of the three rift belts was due to melting of the hydrous lithospheric mantle due to variable amounts of rifting. Any lithospheric loading mechanism for generating post-tholeiite alkalic lavas does not seem feasible for the Deccan; nor can it explain the pre-tholeiite alkaline magmatism in the Deccan. Similarly, conductive heating of the lithosphere by the plume cannot have generated the alkalic melts. Some amount of actual rifting did occur. Direct melt supply from the plume is not necessary for magmatism in the rifts, though it seems to have occurred in some cases. Our documentation of indigenous magmatism for the three rift belts calls into question any attempts at inferring the size of the plume head from synchroneity in geochronologic data alone, and we negate the possibility or necessity of large-distance transport of magmas from the plume through the lithosphere, to feed the rifts. Recent evidence indicates that alkalic magmatism north of the main Deccan outcrop preceded the main tholeiite phase by ˜ 3 MY. The Cambay graben was active 3.5 MY before the main tholeiite phase. As the alkalic complexes at the northern end of this graben are 68.5 Ma in age (so far the oldest well-proven Deccan-related rocks), they are the first expression of the Réunion plume, and the borehole picrites from the triple junction area, until now

  7. Secular and tidal strain across the Main Ethiopian Rift (United States)

    Bilham, Roger; Bendick, R.; Larson, K.; Mohr, P.; Braun, J.; Tesfaye, S.; Asfaw, L.

    Using a combination of laser ranging and GPS data acquired between 1969 and 1997 we derive a separation velocity for the Somali and Nubian plates in Ethiopia (4.5±1 mm/yr at N108±10E). This vector is orthogonal to the NNE-trending neotectonic axis (Wonji fault belt) of the Ethiopian rift axis. Current rifting is concentrated within a 33-km-wide zone that includes a 7-km-wide belt of late Quaternary faulting where maximum surface strain rates are comparable to those at active plate boundaries (0.1 μstrain/yr). The strain-field suggests that thin (<5 km) elastic crust separates thick continental lithosphere, a geometry quite different from oceanic rifting, and a mechanical configuration that favors the amplification of regional strain. Semidiurnal strain tides, however, as measured by kinematic GPS methods are not amplified along or across the rift, indicating that the rift zone's low rigidity applies only at periods of years.

  8. Geoelectric structure of northern Cambay rift basin from magnetotelluric data (United States)

    Danda, Nagarjuna; Rao, C. K.; Kumar, Amit


    Broadband and long-period magnetotelluric data were acquired over the northern part of the Cambay rift zone along an east-west profile 200 km in length. The decomposed TE- and TM-mode data were inverted using a 2-D nonlinear conjugate gradient algorithm to obtain the lithospheric structure of the region. A highly conductive ( 1000 S) layer was identified within the Cambay rift zone and interpreted as thick Quaternary and Tertiary sediments. The crustal conductors found in the profile were due to fluid emplacement in the western part, and the presence of fluids and/or interconnected sulfides caused by metamorphic phases in the eastern part. The demarcation of the Cambay rift zone is clearly delineated with a steeply dipping fault on the western margin, whereas the eastern margin of the rift zone gently dips along the NE-SW axis, representing a half-graben structure. A highly resistive body identified outside the rift zone is interpreted as an igneous granitic intrusive complex. Moderately conductive (30-100 Ω-m) zones indicate underplating and the presence of partial melt due to plume-lithosphere interactions.[Figure not available: see fulltext.

  9. Microphysical Characterization of Aerosol Signatures over Greece

    Directory of Open Access Journals (Sweden)

    Akshath Sharma


    Full Text Available A detailed microphysical characterization is presented for aerosol spectra over three major areas over Greece, namely- the Area West of Crete (AWC, the Greater Thessaloniki area (GTA and the Greater Athens Area (GAA based on measurements made by Varotsos (2005. Aerosol size distributions along with cloud droplet concentrations were gathered from data collected from the Forward Scattering Spectrometer Probe (FSSP-300 and Passive Cavity Aerosol Spectrometer Probe (PCASP-100X flown on a Falcon aircraft over Greece (Varotsos, 2005. However, the microphysical and dynamical characterisation of the observations were left largely unexplored (for this later paper, particularly with regard to their growth and activation into cloud condensation nuclei. A suite of models involving Large Eddy Simulations and an Adiabatic Parcel Model were used to achieve this. The UK Met Office large eddy model (LEM reveals that mild to moderate updraughts in the range of 0.5 ms-1 to 2 ms-1 were present over Athens during June 1997, over the regions containing the aerosol bands. The sophisticated parcel model was then been applied to this data to study the growth of aerosol in the updraughts present and further, to explore the possibility of rainfall. It is found that the grown droplets have radii spanning a range of 6 μm to 100 μm indicating a hundredfold increase over initial size and the region spanning height from 2700 to 3000 meters contains precipitable water.

  10. Tectonics and sedimentology of post-rift anomalous vertical movements: the rifted margin of Morocco (United States)

    Bertotti, Giovanni; Charton, Remi; Luber, Tim; Arantegui, Angel; Redfern, Jonathan


    Roughly 15 years ago it was discovered that substantial parts of the Morocco passive continental margin experienced km-scale, post-rift exhumation. It was predicted that the sands resulting from the associated erosion would be present in the offshore and potentially form hydrocarbon reservoirs. At the same time, anomalous post-rift vertical movements have been documented in various localities of the world and rifted continental margins are at present exciting objects of research. Following intense research efforts the knowledge of the kinematics of vertical movements and their implications for sedimentary systems is increasing. The low-T geochronology initially limited to the classical Meseta-Massif Ancien de Marrakech transect has been expanded reaching the Reguibate Massif to the S and covering, possibly more importantly, one transect in E-W direction along the Anti Atlas. Exhumation occurred along two dominant trends. In N-S direction a several hundred-kilometers long exhuming domain developed roughly parallel to the Atlantic margin. Changes in magnitude and timing of exhumation are observed along this elevated domain associated with E-W trending undulations. The timing of main stage of upward movement of E-W trending highs seems to be Late Jurassic-Early Cretaceous in the Meseta and High Atlas and somewhat older, Early to Middle Jurassic, in the Anti-Atlas and Reguibate. The discovery of E-W trending highs and lows has major implication for sediment distribution and dispersal. At the large scale, it means that the drainage basins were smaller than initially predicted. This seems to be compatible with the paucity of sands encountered by recent exploration wells drilled offshore Morocco. At the scale of several kilometers, W-E trending anticlines and synclines developed in a generally subsiding coastal environment. These folds often had an expression at the sea floor documented by ravinement surfaces and (Jurassic) reef build-ups on top of the anticlines

  11. The Iceland Plate Boundary Zone: Propagating Rifts, Migrating Transforms, and Rift-Parallel Strike-Slip Faults (United States)

    Karson, J. A.


    Unlike most of the Mid-Atlantic Ridge, the North America/Eurasia plate boundary in Iceland lies above sea level where magmatic and tectonic processes can be directly investigated in subaerial exposures. Accordingly, geologic processes in Iceland have long been recognized as possible analogs for seafloor spreading in the submerged parts of the mid-ocean ridge system. Combining existing and new data from across Iceland provides an integrated view of this active, mostly subaerial plate boundary. The broad Iceland plate boundary zone includes segmented rift zones linked by transform fault zones. Rift propagation and transform fault migration away from the Iceland hotspot rearrange the plate boundary configuration resulting in widespread deformation of older crust and reactivation of spreading-related structures. Rift propagation results in block rotations that are accommodated by widespread, rift-parallel, strike-slip faulting. The geometry and kinematics of faulting in Iceland may have implications for spreading processes elsewhere on the mid-ocean ridge system where rift propagation and transform migration occur.

  12. Petroleum system of the Shelf Rift Basin, East China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, A.C.; Armentrout, J.M.; Prebish, M. [Mobil Oil Corp., Dallas, TX (United States)] [and others


    The Tertiary section of the Oujioang and Quiontang Depressions of the East China Sea Basin consists of at least eight rift-related depositional sequences identified seismically by regionally significant onlap and truncation surfaces. These sequences are calibrated by several wells including the Wenzhou 6-1-1 permitting extrapolation of petroleum system elements using seismic facies analysis. Gas and condensate correlated to non-marine source rocks and reservoired in sandstone at the Pinghu field to the north of the study area provides an known petroleum system analogue. In the Shelf Rift Basin, synrift high-amplitude parallel reflections within the graben axes correlate with coaly siltstone strata and are interpreted as coastal plain and possibly lacustrine facies with source rock potential. Synrift clinoform seismic facies prograding from the northwest footwall correlate with non-marine to marginal marine conglomerate, sandstone and siltstone, and are interpreted as possible delta or fan-delta facies with reservoir potential although porosity and permeability is low within the Wenzhou 6-1-1 well. Post-rift thermal sag sequences are characterized by parallel and relatively continuous seismic reflections and locally developed clinoform packages. These facies correlate with porous and permeable marine sandstone and siltstone. Shales of potential sealing capacity occur within marine flooding intervals of both the synrift and post-rift sequences. Traps consist of differentially rotated synrift fill, and post-rift inversion anticlines. Major exploration risk factors include migration from the synrift coaly source rocks to the post-rift porous and permeable sandstones, and seismic imaging and drilling problems associated with extensive Tertiary igneous intrusions.

  13. Petroleum system of the Shelf Rift Basin, East China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, A.C.; Armentrout, J.M.; Prebish, M. (Mobil Oil Corp., Dallas, TX (United States)) (and others)


    The Tertiary section of the Oujioang and Quiontang Depressions of the East China Sea Basin consists of at least eight rift-related depositional sequences identified seismically by regionally significant onlap and truncation surfaces. These sequences are calibrated by several wells including the Wenzhou 6-1-1 permitting extrapolation of petroleum system elements using seismic facies analysis. Gas and condensate correlated to non-marine source rocks and reservoired in sandstone at the Pinghu field to the north of the study area provides an known petroleum system analogue. In the Shelf Rift Basin, synrift high-amplitude parallel reflections within the graben axes correlate with coaly siltstone strata and are interpreted as coastal plain and possibly lacustrine facies with source rock potential. Synrift clinoform seismic facies prograding from the northwest footwall correlate with non-marine to marginal marine conglomerate, sandstone and siltstone, and are interpreted as possible delta or fan-delta facies with reservoir potential although porosity and permeability is low within the Wenzhou 6-1-1 well. Post-rift thermal sag sequences are characterized by parallel and relatively continuous seismic reflections and locally developed clinoform packages. These facies correlate with porous and permeable marine sandstone and siltstone. Shales of potential sealing capacity occur within marine flooding intervals of both the synrift and post-rift sequences. Traps consist of differentially rotated synrift fill, and post-rift inversion anticlines. Major exploration risk factors include migration from the synrift coaly source rocks to the post-rift porous and permeable sandstones, and seismic imaging and drilling problems associated with extensive Tertiary igneous intrusions.

  14. US-Africa collaborative research on incipient continental rift zones (United States)

    Atekwana, E. A.


    Since 1999, we have been conducting research in Botswana in collaboration with colleagues at the University of Botswana (UB). Recently, we have expanded our research activities to include the University of Zambia (UNZA). The goal of the collaborative efforts center on investigating geologic processes operating during the initial stages of continental extension. During student training, US students partner with peers from UB and UNZA to conduct field-based research within a multi-disciplinary framework focused on investigating the interplay between neotectonics and surficial processes due to rifting. The student projects are designed to: 1) assess the role of pre-existing structures on rift basin development; 2) determine fault kinematics and direction of rift extension; 3) characterize the geometry of the basins; 4) assess current models for fault growth and propagation and linkage to form border faults; 5) investigate environmental change information preserved in rift basin sediments; 6) determine how magma below the rift basin affects surface water chemical properties; and 7) develop tectonic and geologic models for the evolution of rift basins during the incipient stages of continental extension. Our goal is to provide is to improve research and education in developing countries while providing talented and motivated US students with hands-on field research experience in near surface geophysical surveying, field geologic mapping, GPS mapping, and geochemical and hydrogeologic techniques necessary for addressing basic research questions in the geosciences, as well as resources exploration (e.g., hydrocarbon, water resources, mineral, geothermal, etc.). Our US students acquire an enriching cultural experience, make personal contacts, and build relationships that will form the core of future international research collaborations. At the same time, project activities introduce the African students to state-of the art geophysical equipment and research methodologies

  15. The Global Financial Crisis and its consequences in Greece.


    Boiteux, Tristan; Ussing, Jonatan


    In Greek and German newspapers we can point the persistency of a constant conflict in the past few years. The German newspapers criticise Greece’s gestion and culture as factors of the financial crisis striking in Greece. On the other hand, Greek newspapers blame Angela Merkel and Germany for the austerity plans implemented in Greece. It is to be understood that Greece is indebted to some EU member states that have loaned money, one being of course Germany (The Economist 2013). There is ...

  16. Some characteristics of the seismicity and the stress field in the Panxi rift zone (United States)

    Zheng, Jian-Zhong; Xu, Wen-Yue; Liu, Jin; Zou, Ying


    Some characteristics of the horizontal distribution of the earthquakes, the focus depth distribution, distribution of the earthquakes with time, b-values, fault slip rates and stress field in the Panxi rift zone have been investigated. The results are as follows: (1) Earthquakes with M ⩾ 4.7 occurred mainly along the major faults in the Panxi rift zone. Earthquake activity is greater along the sides of the Panxi rift zone than along its axis. Earthquakes with M ⩾ 6 occurred along the bounding faults of the Panxi rift zone. The small earthquakes exhibit a random distribution. (2) The focal depths along the axis of the Panxi rift zone are shallow (5-20 km), but the focal depths outside the rift zone are deeper (6-40 km). (3) The b-values in the Panxi rift zone are 0.58-0.75. (4) The correlation of the seismicity between the Panxi rift zone and the eastern India-Eurasian collision zone is high. (5) The fault planes in the Panxi rift zone are nearly vertical and strike-slip. The fault slip rates in the Panxi rift zone are 0.13-0.19 cm/yr. (6) The maximum principal compressive stress axis in the Panxi rift zone is nearly horizontal, NNW-SSE in direction. According to the above results, a dynamic model for the aborting process of the Panxi rift zone is suggested.

  17. Sensitivity of the East African rift lakes to climate variability (United States)

    Olaka, L.; Trauth, M. H.


    Lakes in the East African Rift have provided excellent proxies to reconstruct past climate changes in the low latitudes. The lakes occupy volcano-tectonic depressions with highly variable climate and hydrological setting, that present a good opportunity to study the climatic and hydrogeological influences on the lake water budget. Previous studies have used lake floor sediments to establish the sensitivity of the East African rift lakes. This study focuses on geomorphology and climate to offer additional or alternative record of lake history that are key to quantifying sensitivity of these lakes as archives to external and internal climatic forcings. By using the published Holocene lake areas and levels, we analyze twelve lakes on the eastern arm of the East African rift; Ziway, Awassa, Turkana, Suguta, Baringo, Nakuru, Elmenteita, Naivasha, Natron, Manyara and compare with Lake Victoria, that occupies the plateau between the east and the western arms of the rift. Using the SRTM data, Hypsometric (area-altitude) analysis has been used to compare the lake basins between latitude 80 North and 30 South. The mean elevation for the lakes, is between 524 and 2262 meters above sea level, the lakes' hypsometric integrals (HI), a measure of landmass volume above the reference plane, vary from 0.31 to 0.76. The aridity index (Ai), defined as Precipitation/ Evapotranspiration, quantifies the water available to a lake, it encompasses land cover and climatic effects. It is lowest (arid) in the basin between the Ethiopian rift and the Kenyan rift and at the southern termination of the Kenyan Rift in the catchments of lake Turkana, Suguta, Baringo and Manyara with values of 0.55, 0.43, 0.43 and 0.5 respectively. And it is highest (wet) in the catchments of, Ziway, Awassa, Nakuru and Naivasha as 1.33,1.03 and 1.2 respectively, which occupy the highest points of the rift. Lake Victoria has an index of 1.42 the highest of these lakes and receives a high precipitation. We use a

  18. Imprint of salt tectonics on subsidence patterns during rift to post-rift transition: The Central High Atlas case study (United States)

    Moragas, Mar; Vergés, Jaume; Saura, Eduard; Diego Martín-Martín, Juan; Messager, Grégoire; Hunt, David William


    During Mesozoic time, the extensional basin of the Central High Atlas in Morocco underwent two consecutive rifting events: Permo-Triassic and Early-Middle Jurassic in age. However, a review of the literature reveals that the precise timing of the Early-Middle Jurassic rift and post-rift transition varies depending of the analysed area. The discrepancy about rifting ages is associated with the general lack of normal faulting cutting post-Lower Jurassic strata and the presence of significant salt diapiric activity during Early and Middle Jurassic in the central part of the basin. To evaluate the influence on subsidence patterns of the interaction between both extensional and salt tectonics, we present new subsidence data from diverse paleogeographic and tectonic settings of the Central High Atlas rift basin. From the periphery of the basin, the Djebel Bou Dahar platform-basin system corresponds to a shallow carbonate platform developed on top of a basement high, controlled and bounded by normal faults. The results of the subsidence analysis show long-term and low-rate of tectonic and total subsidence (0.06 and 0.08 mmyr-1 respectively). The roughly parallel evolution of both total and tectonic subsidence curves indicates the tectonic influence of the platform-basin system, as corroborated by the syndepositional fault activity of the outcropping Sinemurian-Pliensbachian normal faults. Contrarily, the rift axis is characterised by the presence of diapiric salt ridges and minibasins as in the Tazoult-Amezraï area and Imilchil diapiric province. Comparison between subsidence curves from the SE flank of the Tazoult salt wall and from Amezraï minibasin centre shows that, from Pliensbachian to Aalenian, the tectonic and total subsidence rates of the Amezraï minibasin (between 0.17-0.32 mmyr-1 and 0.38-0.98 mmyr-1) are two-fold their equivalent rates in the Tazoult salt wall. Amezraï minibasin values are in agreement with the values from Imilchil minibasins (tectonic and

  19. Twins in Ancient Greece: a synopsis. (United States)

    Malamitsi-Puchner, Ariadne


    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality.

  20. Suicide in Greece: 2001-2011. (United States)

    Kontaxakis, V; Papaslanis, Th; Havaki-Kontaxaki, B; Tsouvelas, G; Giotakos, O; Papadimitriou, G Ν


    Since 2008 several European countries have fallen into a financial crisis. This crisis has mainly affected the Greek population. The lower of income and the increase of unemployment as consequences of crisis lead to negative effects on people's mental health. Usually, in periods of economic crisis there is an increase of suicidality of population. The aim of this study is to examine the changes of suicide rates in Greece during the last decade (2001-2011) with particular consideration in the recent period of economic crisis (2008-2011). Data regarding the greek general population and the crude data on suicides were obtained from the Hellenic Statistical Authority (ELSTAT). We assessed the specific suicide rate, i.e. the number of suicide cases per 100.000 inhabitants (SSR) using population data on the 2001 and 2011 census. Yearly and mean total, age and sex-SSR were calculated in five years age groups. There were no suicide cases among children under the age of fifteen. We compared total and male, female SSR during the period before the crisis (2001-2007) and during the crisis (2008-2011). During the decade 2001-2011 a total number of 4133 suicide cases were recorded. There were 3423 (82.8%) male suicides and 710 (17.2%) female suicides. During the decade 2001-2011 total SSR increased by 38.4%. In males increased by 33.1% and in females by 69.6%. In the period before the crisis (2001-2007) total SSR decreased by 3.9%. In males decreased by 8.4% but in females increased by 22.3%. During the period of crisis (2008-2011) total SSR increased by 27.2%. In males increased by 26.9% and in females by 28.5%. There was a statistically significant increase in total SSR during the crisis regarding subjects 50-54 years old (t=3.43, p=0.007) and in total SSR of males (t=2.31, p=0.047) as well as of the males age groups 50-54 (t=3.56, p=0.006), 45-49 (t=2.87, p=0.02), 30-34 (t=2.96, p=0.02). There were no statistically significant differences both in total SSR and in SSR of all

  1. Greece Financial Crisis and Quality of Life. (United States)

    Mechili, Aggelos E; Kalokairinou, Athena; Kaitelidou, Dafni; Diomidous, Marianna


    The last six years the global community is facing an economic crisis that first appeared in USA. This crisis has a lot of impacts especially in health sector. Unemployment, job insecurity and the loss of disposable income have a significant impact in health too. The main objective of this research was to investigate the quality of life of the general population in Greece during the financial crisis. To collect the data it has been used the Greek version of Short Form (36) Health Survey (SF-36v2). In general, income, level of education, cohabitation and parenthood had a significant impact in quality of life. As a conclusion, unemployed participants' score was lower in the entire dimensions and in the two summary scales too.

  2. Legal capacity of the elderly in Greece. (United States)

    Giannouli, Vaitsa; Tsolaki, Magda


    Legal capacity of the elderly people in Greece is of great legal, medical and social importance, but has received little attention till now from medical literature. This paper aims to study whether elderly people with dementia are able to participate in legal contracts like sales, purchases, loans, leases, donations and testaments. We tried to introduce a new test for the above legal-financial contracts and show some preliminary findings. The test consists of six examined relevant domains concerning basic monetary skills, cash transactions, bank statement management, financial conceptual knowledge, knowledge of potential heirs (beneficiaries) and assets/estate and finally the decision making process for different dilemmas on sales, purchases, loans, leases, donations and testaments. We studied 203 people. Eighty three people were healthy, 64 with Alzheimer's disease (AD) (10 with severe AD, 22 with moderate, and 32 with mild AD), 10 with Parkinson's disease (PD), and 46 with amnestic Mild Cognitive Impairment (aMCI). Individuals were included in the study only if they were aged 60 and over and only if they had a partner or a guardian who could give information on the individual's daily living. The exclusion criteria were predefined as follows: history of any other mental health disease and/or any other serious somatic health disease except for their official diagnosis of dementia. Results showed statistically significant differences with all three groups of patients characterized as incapable for legal-financial actions. Patients with severe AD (PImpairment and healthy elders) show a significantly different profile on all examined domains of this new test according to their diagnosis, b) people with MCI from Greece do face problems in the domains outlined above (mainly financial decision making problems), and that c) subsequent changes in the Greek law should be made.

  3. Educational reform in Greece: Central concepts and a critique

    National Research Council Canada - National Science Library

    Panayota Gounari; George Grollios


      The case of Greece as the most recent neoliberal experiment can provide valuable insights not only about a generalized attack on the welfare state and the public good, but also about the radical...

  4. Economic Problems of Greece and Their Influence on International Tourism

    Directory of Open Access Journals (Sweden)

    Kristina A. Menshikova


    Full Text Available The article deals with key economic issues of Greece and their influence on development of international tourism. Such tourist attractions as: popular cities, resorts, wharfs and thermal springs are presented.

  5. Prof. Nanopoulos visits Hill Primary School in Greece

    CERN Multimedia


    This video is an extract of a reportage broadcasted by SKAI TV in Greece about the visit of Prof. Dimitri Nanopoulos to Hill Primary School, the oldest operating school in Greece. The video describes a breakthrough education programme aimed at introducing big ideas in physics, particle physics and cosmology to K-6 students through a pedagogical approach that promotes inquiry, creativity and hands-on experimentation with the use everyday materials.

  6. Promoting Sport Participation in Greece: Issues and Challenges


    Panagiota Balaska; Charilaos Kouthouris


    Due to the absence of national sport participation data in Greece, research and information is still limited. The present paper aimed to report on annual sport participation rates and frequency of sport participation, demographic differences, and constraints on sport participation, among young and middle-aged parents in Greece. Three hundred young and middle-aged parents participated in the study. The results indicated low annual sport participation rates and low frequency of sport participat...

  7. Job satisfaction and employment characteristics of independent accountants in Greece


    Σπάθης, Χαράλαμπος Τ.


    The current study examine the job satisfaction and employment characteristics of independent accountants in Greece. Uses a sample of 306 independent accountants from Greece. The majority of independent accountants (73%) answered that they were satisfied with their choice of career. With respect to satisfaction with i) recognition of the work of an accountant and ii) fees, this is at a satisfactory level, above the middle point of the scale. This shows, however, that independent ac...

  8. First earthworm (Oligochaeta: Lumbricidae record from Sithonia Peninsula (Greece

    Directory of Open Access Journals (Sweden)



    Full Text Available The paper deals with the earthworm diversity of Chalkidiki Peninsula, Greece. Aporrectodea longa (Ude, 1885 proved to be new species for the fauna of Greece and also represents the first earthworm record from Sithonia Peninsula. According to the literature and authors data 14 earthworm taxa are registered from the explored region. The paper underlines lumbricid richness of Chalkidiki Peninsula and provides information about the zoogeographical position of the earthworm species present.

  9. First earthworm (Oligochaeta: Lumbricidae) record from Sithonia Peninsula (Greece)




    The paper deals with the earthworm diversity of Chalkidiki Peninsula, Greece. Aporrectodea longa (Ude, 1885) proved to be new species for the fauna of Greece and also represents the first earthworm record from Sithonia Peninsula. According to the literature and authors data 14 earthworm taxa are registered from the explored region. The paper underlines lumbricid richness of Chalkidiki Peninsula and provides information about the zoogeographical position of the earthworm species...

  10. Pediatric Burns at The Rift Valley Provincial General Hospital ...

    African Journals Online (AJOL)

    Aim To determine the etiology and outcome of pediatric burns (0-12 years). Design A retrospective study of burn victims hospitalized at the Rift Valley Provincial General Hospital, Nakuru, Kenya from April 2004 to March 2007. Method Charts of all children hospitalized for burn injury were reviewed for patient demographics, ...

  11. Pediatric Burns at The Rift Valley Provincial General Hospital ...

    African Journals Online (AJOL)

    surgical/female burn ward were eligible. On average the ward admits 680 patients a year out of which 170 pa- tients (25.7 %) are due to pediatric burns. The Hospital attracts patients mostly from low socioeconomic status. Pediatric Burns at The Rift Valley. Provincial General Hospital, Nakuru,. Kenya. Author: Oduor P.R. ...

  12. Geology of the Elephanta Island fault zone, western Indian rifted ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 1. Geology of the Elephanta Island fault zone, western Indian rifted margin, and its significance for understanding the Panvel flexure. Hrishikesh Samant Ashwin Pundalik Joseph D'souza Hetu Sheth Keegan Carmo Lobo Kyle D'souza Vanit Patel. Volume ...

  13. 3-D Numerical Stratigraphic Forward Modeling of Rifts (United States)

    Lovely, P. J.; Harris, A.; Baumgardner, S. E.; Engelder, T.; Sun, T.; Lyons, R. P.; Granjeon, D.


    Continental rifts are of great interest and relevance to scientists and the general public because they contain numerous depositional environments at relatively compressed spatiotemporal scales, continuous climate records, and hydrocarbon resources. The interaction of climate, sediment routing, and tectonism controls the distribution and continuity of the depositional environments, but these relationships are nonlinear and complex. Conceptual stratigraphic models provide useful insight into facies distribution but are typically qualitative and may not capture the full range of geologically plausible scenarios generated by these interactions. Here, we use a numerical forward stratigraphic model to demonstrate that a deterministic, nonlinear diffusion-based sediment transport model can approximate key tectonostratigraphic processes interpreted from continental rift systems. The sediment transport model acts upon a simple elastic tectonic model that approximates appropriate distributions of subsidence and uplift associated with a schematic fault architecture typical of early stage continental rifting. Comparison of model results to observations of outcrops and the subsurface demonstrates the model's ability to reproduce key tectonostratigraphic features. We also show that such a model may be used to analyze the sensitivity of sand distributions to base-level, sediment, and water flux changes. We present an example analysis with a suite of metrics such as sand thickness, net-to-gross, and mass extraction methods that quantitatively describe the deposits that result from various inputs. This simple sensitivity analysis can be conducted by academic and industry groups to better characterize facies distribution or quantify uncertainties associated with continental rifts.

  14. Probable existence of a Gondwana transcontinental rift system in ...

    Indian Academy of Sciences (India)

    The study indicates a rift system spanning from Arabian plate in the north and extending to southern part of Africa that passes through Indus basin, western part of India and Madagascar, and existed from Late Carboniferous to Early Jurassic. Extensions related to the opening of Neo-Tethys led to the formation of a number of ...

  15. Fluoride Contamination in Drinking Water in the Rift Valley, Kenya ...

    African Journals Online (AJOL)

    A survey of the amount of Fluoride in ground, potable water in Njoro division, Nakuru district and some parts outside the division was conducted to determine the concentration of Fluoride the residents are consuming through water. This area is situated in the Great Rift Valley of East Africa, which is known to have high levels ...

  16. Gravity anomalies, crustal structure and rift tectonics at the Konkan ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 121; Issue 3. Gravity anomalies, crustal structure and rift tectonics at the Konkan and Kerala basins, western continental margin of India. Sheena V Dev M Radhakrishna Shyam Chand C Subrahmanyam. Volume 121 Issue 3 June 2012 pp 813-822 ...

  17. Three-dimensional frictional plastic strain partitioning during oblique rifting (United States)

    Duclaux, Guillaume; Huismans, Ritske S.; May, Dave


    Throughout the Wilson cycle the obliquity between lithospheric plate motion direction and nascent or existing plate boundaries prompts the development of intricate three-dimensional tectonic systems. Where oblique divergence dominates, as in the vast majority of continental rift and incipient oceanic domains, deformation is typically transtensional and large stretching in the brittle upper crust is primarily achieved by the accumulation of displacement on fault networks of various complexity. In continental rift depressions such faults are initially distributed over tens to hundreds of kilometer-wide regions, which can ultimately stretch and evolve into passive margins. Here, we use high-resolution 3D thermo-mechanical finite element models to investigate the relative timing and distribution of localised frictional plastic deformation in the upper crust during oblique rift development in a simplified layered lithosphere. We vary the orientation of a wide oblique heterogeneous weak zone (representing a pre-existing geologic feature like a past orogenic domain), and test the sensitivity of the shear zones orientation to a range of noise distribution. These models allow us to assess the importance of material heterogeneities for controlling the spatio-temporal shear zones distribution in the upper crust during oblique rifting, and to discuss the underlying controls governing oblique continental breakup.

  18. The Reconcavo Basin reservoirs in transition of the pre-rift and rift phases: new discussion; Os reservatorios da Bacia do Reconcavo na transicao das fases pre-rift e rift: nova discussao

    Energy Technology Data Exchange (ETDEWEB)

    Romao, Felipe [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Borghi, Leonardo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)


    The facies analysis of the stratigraphic interval represented by Sergi, Itaparica, and Agua Grande formations (Brotas and Santo Amaro groups) of Reconcavo basin was guided by cores description of the well 1-CAL-1-BA (Caldeirao 1), located in the Northwestern part of the Reconcavo Basin. Sedimentary facies (lithofacies) were described and grouped into four facies association interpreted as fluvial (upper Sergi Fm.), fluvial-lacustrine (Itaparica Fm.), and fluvial-eolian (Agua Grande Fm.) depositional systems; also, forced-regression erosive surfaces (unconformities) and transgressive ones were identified. The analysis of these results points that the upper Sergi Fm. would have subsided as consequence of the early rifting of the basin, creating space for the formation of shallow lake (Itaparica Fm.). This ancient lake undergone several forced regressions due to a continuous early tectonism (rifting), responsible by the sand input into the lake, in a coarsening up cycle topped by the expressive fluvio-eolian system of the Agua Grande Fm. Each forced regression smaller cycle is capped by lake flooding shales. Above this major CU cycle, the intensification of tectonic event subsided the basin and created a deep lake (Candeias Fm.) - the Rift Phase. So, the initial rifting would not have started during a 'Candeias time', but by earlier, in a less intense way. It must be stressed that this interpretation was based solely in only one well, but it's important to keep this new idea in mind for revision or new studies on this interval. (author)

  19. Forecast and Outbreak of Rift valley fever in Sudan, 2007 (United States)

    Background Rift Valley fever (RVF) outbreaks occur during heavy rainfall in various sub-Saharan countries including Kenya, Somalia, and Tanzania and more recently in Saudi Arabia and Yemen. Given the wide geographic and ecological range of RVF virus, it is necessary to monitor large areas for condit...

  20. Rift Valley fever Entomology, Ecology, and Outbreak Risk Factors (United States)

    Rift Valley fever (RVF) is a mosquito-borne zoonotic disease of domestic ruminants and humans in Africa. The disease is most severe in cattle, sheep, and goats, and it causes high mortality in young animals and abortion in adults. Exotic aanimal breeds from areas where RVF is not endemic tend to be ...

  1. Impact of Global Climate on Rift Valley Fever Disease Outbreaks (United States)

    Rift Valley fever is a viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. Since the virus was first isolated in Kenya in 1930 it has caused significant impact to animal and human health and national economies, and it is of concern to the internationa...

  2. Greece's high dentist to population ratio: comparisons, causes, and effects. (United States)

    Koletsi-Kounari, Haroula; Papaioannou, William; Stefaniotis, Theodoros


    Reaching the optimal dentist to population ratio is a common health policy challenge around the world, but while many countries have too few dentists for their populations, Greece is facing the opposite problem. This study was designed to describe and analyze trends in the number and distribution of dentists in Greece over the last thirty years and compare the Greek dentist to population ratio with that of the other twenty-six European Union (EU) countries. Demographic data for Greece were obtained from the Hellenic Dental Association and the National Statistical Service of Greece and were analyzed using nonparametric statistical tests. Data for the other EU countries were derived from various authoritative sources. In Greece, the number of dentists per 10,000 inhabitants increased significantly (pdentists during the decade 1979-88 (30.4 percent) was significant (pdentists practiced in the Attica Prefecture (Athens) (55.2 percent and 52.6 percent, respectively), but this situation changed significantly in 2007 (pdentists remained almost the same from 1982 until 2007, but female dentists' location of practice changed significantly (pdentist to population ratio, Greece has significant oral health access problems.

  3. East Antarctic rifting triggers uplift of the Gamburtsev Mountains. (United States)

    Ferraccioli, Fausto; Finn, Carol A; Jordan, Tom A; Bell, Robin E; Anderson, Lester M; Damaske, Detlef


    The Gamburtsev Subglacial Mountains are the least understood tectonic feature on Earth, because they are completely hidden beneath the East Antarctic Ice Sheet. Their high elevation and youthful Alpine topography, combined with their location on the East Antarctic craton, creates a paradox that has puzzled researchers since the mountains were discovered in 1958. The preservation of Alpine topography in the Gamburtsevs may reflect extremely low long-term erosion rates beneath the ice sheet, but the mountains' origin remains problematic. Here we present the first comprehensive view of the crustal architecture and uplift mechanisms for the Gamburtsevs, derived from radar, gravity and magnetic data. The geophysical data define a 2,500-km-long rift system in East Antarctica surrounding the Gamburtsevs, and a thick crustal root beneath the range. We propose that the root formed during the Proterozoic assembly of interior East Antarctica (possibly about 1 Gyr ago), was preserved as in some old orogens and was rejuvenated during much later Permian (roughly 250 Myr ago) and Cretaceous (roughly 100 Myr ago) rifting. Much like East Africa, the interior of East Antarctica is a mosaic of Precambrian provinces affected by rifting processes. Our models show that the combination of rift-flank uplift, root buoyancy and the isostatic response to fluvial and glacial erosion explains the high elevation and relief of the Gamburtsevs. The evolution of the Gamburtsevs demonstrates that rifting and preserved orogenic roots can produce broad regions of high topography in continental interiors without significantly modifying the underlying Precambrian lithosphere. © 2011 Macmillan Publishers Limited. All rights reserved

  4. Magma ascent and emplacement in a continental rift setting: lessons from alkaline complexes in active and ancient rift zones (United States)

    Hutchison, William; Lloyd, Ryan; Birhanu, Yelebe; Biggs, Juliet; Mather, Tamsin; Pyle, David; Lewi, Elias; Yirgu, Gezahgen; Finch, Adrian


    A key feature of continental rift evolution is the development of large chemically-evolved alkaline magmatic systems in the shallow crust. At active alkaline systems, for example in the East African Rift, the volcanic complexes pose significant hazards to local populations but can also sustain major geothermal resources. In ancient rifts, for example the Gardar province in Southern Greenland, these alkaline magma bodies can host some of the world's largest rare element deposits in resources such as rare earths, niobium and tantalum. Despite their significance, there are major uncertainties about how such magmas are emplaced, the mechanisms that trigger eruptions and the magmatic and hydrothermal processes that generate geothermal and mineral resources. Here we compare observations from active caldera volcanoes in the Ethiopian Rift with compositionally equivalent ancient (1300-1100 Ma) plutonic systems in the Gardar Rift province (Greenland). In the Ethiopian Rift Valley we use InSAR and GPS data to evaluate the temporal and spatial evolution of ground deformation at Aluto and Corbetti calderas. We show that unrest at Aluto is characterized by short (3-6 month) accelerating uplift pulses likely caused by magmatic fluid intrusion at 5 km. At Corbetti, uplift is steady ( 6.6 cm/yr) and sustained over many years with analytical source models suggesting deformation is linked to sill intrusion at depths of 7 km. To evaluate the validity of these contrasting deformation mechanisms (i.e. magmatic fluid intrusion and sill emplacement) we carried out extensive field, structural and geochemical analysis in the roof zones of two alkaline plutons (Ilímaussaq and Motzfeldt) in Greenland. Our results show that the volatile contents (F, Cl, OH and S) of these magmas were exceptionally high and that there is evidence for ponding of magmatic fluids in the roof zone of the magma reservoir. We also identified extensive sill networks at the contact between the magma reservoir and the

  5. The timing of uplift, volcanism, and rifting peripheral to the Red Sea: A case for passive rifting? (United States)

    Bohannon, Robert G.; Naeser, Charles W.; Schmidt, Dwight L.; Zimmermann, Robert A.


    Prior to the formation of the Red Sea the northeastern Afro/Arabian continent had low relief and was largely below sea level from the Late Cretaceous to the early Oligocene. The events leading to the formation of the Red Sea followed the sequence (1) alkaline volcanism and rifting beginning about 30-32 Ma affecting a narrow linear zone in the continent, (2) rotational block faulting and detachment faulting, well underway by 25 Ma, (3) gabbro and diorite magmatism, andesite to rhyolite volcanism, and fine-grained nonmarine sedimentation in the rift between 20 and 25 Ma, (4) fine-grained marine sedimentation in the rift as the early shelves started to subside in the middle Miocene, and (5) uplift of the adjacent continents (about 3 km) and subsidence of the shelves (about 4 km) between 13.8 and 5 Ma. The youth of the uplift is suggested by 44 fission track dates on apatites from rocks of the Proterozoic Arabian Shield that range in age from 13.8 to 568 Ma. The youngest of these ages, coupled with the present high relief along the Arabian escarpment and published heat flow measurements, indicate that 2.5-4 km uplift has occurred in the last 13.8 m.y. The sequence volcanism/rifting followed by uplift leads to our adoption of a passive mantle model for rift origin. Models that require uplift to create the rift are rejected, because of the late uplift. We advocate a model of lithospheric extension caused by two-dimensional plate stress over those requiring tractional drag at the base of the lithosphere caused by vigorous flow in the asthenosphere. It is acknowledged that traction models could explain the observed data, but they imply a rigid, static lithosphere and seem to require a link between the direction of flow in the asthenosphere and plate motions. Neither requirement is necessary in the extension model. The rift starts with mechanical extension in a narrow zone of lithosphere between 25-32 Ma in our model. The thinned lithosphere is replaced by upwelling

  6. The Lake Albert Rift (uganda, East African Rift System): Deformation, Basin and Relief Evolution Since 17 Ma (United States)

    Brendan, Simon; François, Guillocheau; Cécile, Robin; Olivier, Dauteuil; Thierry, Nalpas; Martin, Pickford; Brigitte, Senut; Philippe, Lays; Philippe, Bourges; Martine, Bez


    This study is based on a coupled basin infilling study and a landforms analysis of the Lake Albert Rift located at the northern part of the western branch of the East African Rift. The basin infilling study is based on both subsurface data and outcrops analysis. The objective was to (1) obtain an age model based on onshore mammals biozones, (2) to reconstruct the 3D architecture of the rift using sequence stratigraphy correlations and seismic data interpretation, (3) to characterize the deformation and its changes through times and (4) to quantify the accommodation for several time intervals. The infilling essentially consists of isopach fault-bounded units composed of lacustrine deposits wherein were characterized two major unconformities dated at 6.2 Ma (Uppermost Miocene) and 2.7 Ma (Pliocene-Pleistocene boundary), coeval with major subsidence and climatic changes. The landforms analysis is based on the characterization and relative dating (geometrical relationships with volcanism) of Ugandan landforms which consist of stepped planation surfaces (etchplains and peplians) and incised valleys. We here proposed a seven-steps reconstruction of the deformation-erosion-sedimentation relationships of the Lake Albert Basin and its catchments: - 55-45 Ma: formation of laterites corresponding to the African Surface during the very humid period of the Lower-Middle Eocene; - 45-22: stripping of the African Surface in response of the beginning of the East-African Dome uplift and formation of a pediplain which associated base level is the Atlantic Ocean; - 17-2.5 Ma: Initiation of the Lake Albert Basin around 17 Ma and creation of local base levels (Lake Albert, Edward and George) on which three pediplains tend to adapt; - 18 - 16 Ma to 6.2 Ma: "Flexural" stage (subsidence rate: 150-200 m/Ma; sedimentation rate 1.3 km3/Ma between 17 and 12 Ma and 0.6 km3/Ma from 12 to 6 Ma) - depocenters location (southern part of Lake Albert Basin) poorly controlled by fault; - 6.2 Ma to 2

  7. Geochronological and geochemical assessment of Cenozoic volcanism from the Terror Rift region of the West Antarctic Rift System (United States)

    Rilling, Sarah E.

    The work presented in this dissertation explains results from three different methods to determine the relation between tectonism and rift-related volcanism in the Terror Rift region of the West Antarctic Rift System (WARS). Alkaline lavas from seven submarine features, Beaufort Island and Franklin Islands, and several locations near Mt Melbourne were dated by 40Ar/39Ar geochronology and analyzed for elemental and isotopic chemical signatures. Each chapter addresses a different aspect of the hypothesis that the presence of volatiles, primarily H2O or CO2, in the magma source has led to anomalously high volumes of magmatism after rift-related decompressional melting rather than requiring an active mantle plume source. Chapter 2 provides the temporal framework, illustrating that the sampled features range in age from 6.7 Ma to 89 ka, post-dating the main Miocene age phase of Terror Rift extension. Chapter 3 illustrates the traditional enriched elemental and isotopic chemical signatures to support the overall homogeneity of these lavas and previously analyzed areas of the WARS. This chapter also provides a new model for the generation of the Pb isotopic signatures consistent with a history of metasomatism in the magma source. Chapter 4 provides an entirely new chemical dataset for the WARS. The first platinum group element (PGE) abundances and extremely unradiogenic Os isotopic signatures of Cenozoic lavas from Antarctica provide the strongest evidence of melting contributions from a lithospheric mantle source. The combined results from these three studies consistently support the original hypothesis of this dissertation. New evidence suggests that WARS related lavas are not related to a mantle plume(s) as previously proposed. Instead, they are generated by passive, decompressional melting of a source, likely a combination of the asthenospheric and lithospheric mantle, which has undergone previous melting events and metasomatism.

  8. Albertine Rift, Uganda: Deformation-Sedimentation-Erosion relationships (United States)

    Simon, Brendan; Guillocheau, François; Robin, Cécile; Dauteuil, Olivier; Nalpas, Thierry; Bourges, Philippe; Bez, Martine; Lays, Philippe


    The Albertine Rift is the northern part of the western branch of the East African Rift that runs over a distance of around 2000 km from Lake Albert in the north to Lake Malawi in the south. Lake Albert Basin is assumed to be a classical half-graben initiated around 12 Ma and oriented NNW-SSW, with a major northwesterly bounding fault - the Bunia fault - located along the western Congolese shoreline (Ebinger, 1989; Pickford & al., 1993). The aim of this study is to understand the relationships between deformation, erosion, and sedimentation of the rift through time by restoring (1) the timing and amplitude of vertical movements (subsidence, uplift), (2) the geometry and paleo-environmental evolution (including climate) of the sedimentary infilling and (3) the geomorphological evolution of the surrounding area and associated erosion budget. Seismic data and outcrops studies suggest a much more complex history than previously described. (1) The age model, mainly based on mammal fossils (Pickford et al., 1993; Van Damme and Pickford, 2003), is debated, but the early stage of the rift is probably Middle Miocene. (2) No half-graben geometry has been characterized: the infilling consists of juxtaposed tabular compartments with sharp thicknesses variations along bounding faults, in response of either low rate extensional or combined strike-slip/extensional movements. The following onshore-offshore evolution is proposed: - Middle Miocene (~ 13 Ma) to Late Miocene (?): rifting 1 - differential subsidence along N60° faults - major deepening from fluvio-deltaic to deep lacustrine environments (maximum flooding at 8 Ma) - uplift, erosion and reworking of weathered profiles - first generation of pediments. - Late Miocene (?) to Late Pliocene (~ 3 Ma): quiescence phase - homogenous subsidence - lacustrine clays interbedded with sandy flood-lobes - uplift, erosion and reworking of ferruginous laterite (iron duricrusts) - second generation of pediments. - Late Pliocene (~ 3Ma) to

  9. Comparative riftology: insights from crustal structure into the evolution of continental rifts and passive continental margins (United States)

    Kley, Jonas; Stein, Carol; Stein, Seth; Keller, Randy; Wysession, Michael; Frederiksen, Andrew


    Continental rifts evolve to seafloor spreading and are preserved in passive margins, or fail and remain as fossil features in continents. Rifts at different stages give insight into these different evolutionary paths. Of particular interest is how volcanic passive margins evolve. These features are characterized by sequences of volcanic rocks yielding magnetic anomalies landward of and sometimes larger than the oldest spreading anomalies. Seaward-dipping reflectors (SDR) occur in stretched continental crust landward of the oldest oceanic crust and are underplated by high-velocity lower crustal bodies. How and when these features form remains unclear. Insights are given by the Midcontinent Rift (MCR), formed by 1.1 Ga rifting of Amazonia from Laurentia, that failed once seafloor spreading was established elsewhere. MCR volcanics are much thicker than other continental flood basalts, due to deposition in a narrow rift rather than a broad region, giving a rift's geometry but a LIP's magma volume. The MCR provides a snapshot of the deposition of a thick highly magnetized volcanic section during rifting. Surface exposures and seismic-reflection data in and near Lake Superior show a rift basin filled by inward-dipping flood basalt layers. Had the rift evolved to seafloor spreading, the basin would have split into two sets of volcanics with opposite-facing SDRs, each with a strong magnetic anomaly. Because the rift formed as a series of alternating half-grabens, structural asymmetries between conjugate margins can naturally occur. Hence the MCR shows that many features form prior to breakup. Because the MCR was massively inverted by regional compression long after it failed and was uplifted, its structure is better known than failed rifts that incurred lesser degrees of inversion. It provides an end member for the evolution of actively extending rifts, characterized by upwelling mantle and negative gravity anomalies, in contrast to failed and inverted rifts without

  10. The formation of the south-eastern part of the Dniepr-Donets Basin: 2-D forward and reverse syn-rift and post-rift modelling.

    NARCIS (Netherlands)

    Stovba, S.M.; Maystrenko, Yu.; Stephenson, R.A.; Kusznir, N.J.


    Forward and reverse modelling of structure and stratigraphy has been used to investigate the syn-rift (Late Devonian) and early post-rift (Carboniferous) evolution of the south-eastern part of the Dniepr-Donets Basin (DDB). Modelling was carried out with and without taking into consideration the

  11. Geomorphic and archaeological -historical evidence for past ealihquakes in Greece

    Directory of Open Access Journals (Sweden)

    H. Maroukian


    Full Text Available Geomorphic observations focused on landforms of marine and fluvial origin such as notches, beachrocks, stream channel shifts, alluvial terraces and knickpoints, when combined with historical and archaeological information are able to date seismic events that took place in the past in some places of the Peloponnesus. At thc Eastern Gulf of Corinth, a seismically active area, all the geomorphic observations fit quite well with the deformation field induced by the action of an offshore fault. At Mycenae, a seismically inactive area with no historical evidence of earthquakes, the archaeological information is the only evidence for past earthquakes while geomorphic data indicate the most probable activated fault. At Sparta, an area of low seismicity but with historical evidence of destructive earthquakes, the geomorphic evidence helps to identify the most likely ruptured fault. At Eliki, a seismically active area with well documented historical activity, the geomorphic data serve to define the causative fault.This paper shows that although historical and archaeological data provide evidence far the occurrence of past earthquakes and often their date, geomorphic observations must be used to identify the causative fault.

  12. Site characteristics of Tuber magnatum in Greece

    Directory of Open Access Journals (Sweden)

    Vasilios Christopoulos


    Full Text Available Day after day it is being demonstrated that Greece hides a buried treasure in its forests. The wild black truffles Tuber aestivum, T. uncinatum, T. brumale and T. melanosporum and the white truffle T. borchii and recently T. magnatum are picked in a variety of forest ecosystems all over the country. The information which has been collected has initiated a national programme on truffle cultivation which, so far, has immense appeal, especially among young farmers. The discovery of carpophores of T. magnatum, the most valued white truffle in the market, triggered the interest in studying the site characteristics, botanical and pedological, in order to help farmers to cultivate the species in similar sites. All carpophores were found under hornbeam (Carpinus orientalis along the banks of a creek on alluvial sediment. Soil analyses of four soil samples from truffle nests showed a narrow range of values of pH in water (7.57–7.78 and 1N KCL (6.94–7.07 and a similar granulometric soil texture.

  13. Burns during Easter festivities in Greece. (United States)

    Pallantzas, A; Kourakos, P; Stampolidis, N; Papagianni, E; Balagoura, A; Stathopoulos, A; Polizoi, A; Emvalomata, A; Evaggelopoulou, M; Castana, O


    Easter is the most important holiday for the Greek Church. It is rich in traditions and rituals but during the Greek Easter festivities, especially at midnight Mass on Easter Saturday night, it is customary to throw fireworks around. These fireworks are not part of the true Easter tradition and they are potentially fatal. Unfortunately, in the past few years, the custom has become more and more popular in Greece. There are some local variations, mainly in the Aegean islands, where homemade rockets are used to have a "rocket war". The rockets consist of wooden sticks loaded with an explosive mixture containing gunpowder and launched from special platforms. Many severe injuries involving loss of sight and limbs as well as major burns are also caused by the use of illegal fireworks at Easter. Every year numerous burn victims are hospitalized. The most affected areas are the face, the upper extremities, and the chest, often in association with slight or severe wounds and injuries. This study presents our department's experience with incidents due to the use of fireworks during Easter festivities.

  14. [Financial crisis and mental health in Greece]. (United States)

    Giotakos, O; Karabelas, D; Kafkas, A


    Several studies indicate an association between economic crises and psychological burden. To investigate the possible impact of the current economic crisis on mental health in Greece, the association between two economic indicators (unemployment and average income) and mental health variables (psychiatric clinic admittance, visits to outpatients' departments and emergency units, suicides, homicides, mortality rates and divorces) was studied. The data were gathered by the Greek Statistical Service and some others were provided by the following hospitals: Eginition Hospital, Psychiatric Hospital of Attica, Athens General Hospital and Evaggelismos Hospital. Simple and multiple regression analyses were performed on the data. There was no significant correlation between the level of unemployment, as well as the average income, and admittance to the psychiatric clinics. A significant correlation was isolated between unemployment and visits to outpatients' department (R2 = 0.40, p = 0.001) and emergency unit (R2 = 0.49, p = 0.0002) of Eginition Hospital. The unemployment rate during the period 1981-2008 was positively associated with the number of homicides (R2 = 0.16, beta = 0.000049, p = 0.03), as well as the number of divorces (R2 = 0.20, beta = 0.005, p = 0.02) during the same period. The average income showed positive association with the visits to both outpatients' department (R2 = 0.55, p positive correlation between the average income and divorce rates (R2 = 0.73, p impact of economic crisis on citizens' mental health.


    Directory of Open Access Journals (Sweden)

    Olga Korol


    Full Text Available The purpose. The impact of foreign debt growth on the social and economic performance of Greece was shown. The parameters of GDP, consumption, interest rates, unemployment and government spendings were analyzed. Methodology. Data obtained for 2001-2014 was used for regression analysis, vector autoregression and as well as Kalman filter. Results. A multi-faced analysis of the debt for EU-member states and Greece in particular was performed. The events and decisions of Greek authorities leading to the crisis were summarized in structural and logical scheme. The recommendations for the economic policy of Greece, based on the performed analysis were suggested. The practical applications. Establishment of all weaknesses and empirical testing of the necessary indicators in this study was the basis for the justification of measures to stabilize the economic situation in Ukraine and Greece. Value/originality. The Mandel-Fleming model and the model of balance of savings-investments was used for the first time for the theoretical interpretation of the nature of the debt crisis in Greece, that under the influence of capital inflows caused by the deterioration of the current account balance and interest rate cuts. The increase in foreign borrowings has led to an increase in the budget deficit and reduction in savings. Also for the first time performed regression-correlation analysis, in particular the Kalman filter is used to study the effect of debt on macroeconomic performance of the Greek economy.

  16. Going East or West? Finnish Travelers in Nineteenth Century Greece

    Directory of Open Access Journals (Sweden)

    Letsios Vassilis


    Full Text Available In this article I will discuss two different attitudes of traveling in mid-nineteenth century Greece, at a crucial time for the “western” or “eastern” orientation of the Greek state. To capture this I will demonstrate aspects of the travel writing of two Finnish travelers in nineteenth century Greece. The first recognized in modern Greece the light of classical antiquity and the importance of its conveying to the west, the second focused on contemporary Greece and its connection with the east. The two travelers, with a common starting point and at about the same time, traveled in a very different way in nineteenth century Greece and with their different skills “opened” different ideological horizons in a place that they both “loved” and “hated” for different reasons. How does the binary “east/west?” relate to the travelers’ expectations and predispositions at a time of the development of modern Greek identities and consciousness?

  17. Seismic hazard of the Kivu rift (western branch, East African Rift system): new neotectonic map and seismotectonic zonation model (United States)

    Delvaux, Damien; Mulumba, Jean-Luc; Sebagenzi Mwene Ntabwoba, Stanislas; Fiama Bondo, Silvanos; Kervyn, François; Havenith, Hans-Balder


    The first detailed probabilistic seismic hazard assessment has been performed for the Kivu and northern Tanganyika rift region in Central Africa. This region, which forms the central part of the Western Rift Branch, is one of the most seismically active part of the East African rift system. It was already integrated in large scale seismic hazard assessments, but here we defined a finer zonation model with 7 different zones representing the lateral variation of the geological and geophysical setting across the region. In order to build the new zonation model, we compiled homogeneous cross-border geological, neotectonic and sismotectonic maps over the central part of East D.R. Congo, SW Uganda, Rwanda, Burundi and NW Tanzania and defined a new neotectonic sheme. The seismic risk assessment is based on a new earthquake catalogue, compiled on the basis of various local and global earthquake catalogues. The use of macroseismic epicenters determined from felt earthquakes allowed to extend the time-range back to the beginning of the 20th century, spanning 126 years, with 1068 events. The magnitudes have been homogenized to Mw and aftershocks removed. From this initial catalogue, a catalogue of 359 events from 1956 to 2015 and with M > 4.4 has been extracted for the seismic hazard assessment. The seismotectonic zonation includes 7 seismic source areas that have been defined on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of thermal springs and earthquake epicenters. The Gutenberg-Richter seismic hazard parameters were determined using both the least square linear fit and the maximum likelihood method (Kijko & Smit aue program). Seismic hazard maps have been computed with the Crisis 2012 software using 3 different attenuation laws. We obtained higher PGA values (475 years return period) for the Kivu rift region than the previous estimates (Delvaux et al., 2016). They vary laterally in function of the tectonic

  18. No Moho uplift below the Baikal Rift Zone

    DEFF Research Database (Denmark)

    Nielsen, Christoffer; Thybo, Hans


    The late Cenozoic Baikal Rift Zone (BRZ) in southern Siberia is composed of several individual topographic depressions and half grabens with the deep Lake Baikal at its center. We have modeled the seismic velocity structure of the crust and uppermost mantle along a 360 km long profile of the Baikal.......4-7.6 ± 0.2 km/s), slightly offset to the northeast from the rift axis. We interpret this feature as resulting from mafic intrusions. Their presence may explain the flat Moho by compensation of lower crustal thinning by intrusion of mafic melts. The Pn wave velocities (8.15-8.2 km/s) are normal for the area...

  19. Integrated Numerical Model for the East African Rift System: Plume-induced Rifting and Continental Break-up from Lake Malawi to Red Sea (United States)

    Koptev, A.; Leroy, S. D.; Calais, E.; Gerya, T.


    We present numerical experiments that target to reveal the role of active mantle plume, far-field tectonic forces and pre-existing lithospheric heterogeneities in structural development of the East African Rift system (EARS). Starting with models capturing the essential geophysical features of the central and southern parts of the EARS (two «cratonic» bodies (Tanzanian craton and Bangweulu block) embedded into a «normal» surrounding lithosphere) we show that development of the magmatic Eastern branch, the amagmatic Western branch and its southern prolongation (Malawi rift) can be the result of non-uniform splitting of some hot plume material that has been initially seeded underneath the southern part of Tanzanian craton. The second series of experiments has been designed in order to investigate northern segment of the EARS where Afro-Arabian plate separation is supposed to be related with the impact of Afar mantle plume. These models permit us to reproduce observed orientation and relative position of two spreading axes (Red Sea, Gulf of Aden) and rifting (Main Ethiopian rift) one. All are joining at Afar triple junction. Finally, for laterally extended experiment we have used parameters of the best-fit models for the southern and northern segments of the EARS in order to define the position of Kenyan plume and the velocity boundary conditions. This model cover all rifting and spreading structure associated with both Afar and Kenyan plumes: Red Sea Rift and the Aden Ridge to the north of the Afar Triple Junction; Main Ethiopian Rift running to the south that continues as the Kenyan Rift; Western Rift and its southern prolongation corresponding to Malawi rift.We argue that main features of the EARS can be reproduced in a relatively simple context of the interaction between two mantle anomalies corresponding to Afar and Kenyan plumes and pre-stressed rheologically stratified continental lithosphere containing only first-order structural heterogeneities (such as

  20. Crustal structure on the northeastern flank of the Kenya rift (United States)

    Prodehl, C.; Jacob, A. W. B.; Thybo, H.; Dindi, E.; Stangl, R.


    The KRISP flank line E converges with the Kenya rift at an angle of about 45° and is approximately parallel to the older Anza graben to the north. The depth to the basement is almost zero along the entire onshore part of the profile with higher velocities at the southeastern end indicative of extensive Precambrian gabbroic intrusions in the upper crust. The Moho shallows steadily from about 35 km at the southeastern end of the profile to about 24 km under Lake Turkana. Even though the Moho rises fairly steadily, there is significant heterogeneity in the crust above it. This shows that the extension is unevenly distributed between the upper and the lower crust. The Moho is laminated and variably reflective. Compared to the KRISP cross-line D further south, the crust is unexpectedly thin and shows extension increasing in a northerly direction. This extension is probably not associated with the Anza and Kenya rifting but with the profile's position on the slope of the Kenya dome. The indications are that there is a relatively abrupt change to a 20-km Moho depth near the Lake Turkana Central shotpoint. This change to a mid-rift crustal thickness occurs not at the postulated margin at the southeastern shore of Lake Turkana but at least 50 km further to the northwest. We suggest that the position of this margin may need to be redefined. The P n velocity is quite high at 8.1 km/s. This may indicate either a cold upper mantle or anisotropy. An upper-mantle reflector has been identified between 15 and 20 km below the Moho. It dips gently away from the rift.

  1. Re-Emergence of Rift Valley Fever in Madagascar

    Centers for Disease Control (CDC) Podcasts


    This podcast describes the re-emergence of Rift Valley Fever in Madagascar during two rainy seasons in 2008 and 2009. CDC epidemiologist Dr. Pierre Rollin discusses what researchers learned about the outbreak and about infections in the larger population in Madagascar.  Created: 5/27/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/27/2010.

  2. Strong Performers and Successful Reformers in Education: Education Policy Advice for Greece (United States)

    OECD Publishing (NJ1), 2011


    The future of Greece's well-being will depend on improving educational performance to boost productivity and improve social outcomes. In the current economic context, with the need to get best value for spending, Greece must and can address inefficiencies in its education system. The challenges are significant. For example, Greece lags behind many…

  3. Geophysical exploration of the Boku geothermal area, Central Ethiopian Rift

    Energy Technology Data Exchange (ETDEWEB)

    Abiye, Tamiru A. [School of Geosciences, Faculty of Science, University of the Witwatersrand, Private Bag X3, P.O. Box Wits, 2050 Johannesburg (South Africa); Tigistu Haile [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)


    The Boku central volcano is located within the axial zone of the Central Ethiopian Rift near the town of Nazareth, Ethiopia. An integrated geophysical survey involving thermal, magnetic, electrical and gravimetric methods has been carried out over the Boku geothermal area in order to understand the circulation of fluids in the subsurface, and to localize the 'hot spot' providing heat to the downward migrating groundwaters before they return to the surface. The aim of the investigations was to reconstruct the geometry of the aquifers and the fluid flow paths in the Boku geothermal system, the country's least studied. Geological studies show that it taps heat from the shallow acidic Quaternary volcanic rocks of the Rift floor. The aquifer system is hosted in Quaternary Rift floor ignimbrites that are intensively fractured and receive regional meteoric water recharge from the adjacent escarpment and locally from precipitation and the Awash River. Geophysical surveys have mapped Quaternary faults that are the major geologic structures that allow the ascent of the hotter fluids towards the surface, as well as the cold-water recharge of the geothermal system. The shallow aquifers are mapped, preferred borehole sites for the extraction of thermal fluids are delineated and the depths to deeper thermal aquifers are estimated. (author)

  4. Basement rift control on oil production in eastern Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, J.B.


    Improved understanding of the central North American rift system (CNARS) offers a new interpretation of the basement structure in certain parts of the Mid-Continent. In eastern Kansas, basement structure can be shown to control oil production from some producing fields. Structural control includes rotated blocks along faults created by horst and graben tectonics typically associated with rift zones. A distinctive gravity signature, the Mid-Continent geophysical anomaly (MGA) is related directly to the CNARS and provides good data for interpretation of the basement structure. Some oil fields can be correlated directly with gravity-interpreted basement structure. Aeromagnetic and Landsat information, combined with the gravity data, further define exploration targets along the general trend of basement features. Migration of thermally matured hydrocarbons into pre-Pennsylvanian, rift generated traps in the ancestral north Kansas basin is postulated. The Nemaha ridge subsequently divided that basin into two smaller basins, the present Salina and Forest City basins. Several exploration targets could exist in this area, with the Arbuckle, Simpson, and Viola units being primary targets. The source of hydrocarbons also may lie in the deep but distant Anadorko basin. An additional totally untested hydrocarbons potential exists in the deep Precambrian/Cambrian sedimentary subbasins created along the flanks of the CNARS. Recent data points to sedimentary columns with depths of approximately 15,000 ft (4500 m) which might be hosts to gas reserves similar to the Rome trough potential of the Appalachian region.

  5. Dike intrusions during rifting episodes obey scaling relationships similar to earthquakes (United States)

    L., Passarelli; E., Rivalta; A., Shuler


    As continental rifts evolve towards mid-ocean ridges, strain is accommodated by repeated episodes of faulting and magmatism. Discrete rifting episodes have been observed along two subaerial divergent plate boundaries, the Krafla segment of the Northern Volcanic Rift Zone in Iceland and the Manda-Hararo segment of the Red Sea Rift in Ethiopia. In both cases, the initial and largest dike intrusion was followed by a series of smaller intrusions. By performing a statistical analysis of these rifting episodes, we demonstrate that dike intrusions obey scaling relationships similar to earthquakes. We find that the dimensions of dike intrusions obey a power law analogous to the Gutenberg-Richter relation, and the long-term release of geodetic moment is governed by a relationship consistent with the Omori law. Due to the effects of magma supply, the timing of secondary dike intrusions differs from that of the aftershocks. This work provides evidence of self-similarity in the rifting process. PMID:24469260


    Directory of Open Access Journals (Sweden)

    Artur Adamczyk


    Full Text Available The main objective of this article is to present the way attitudes towards Albanian people and the perception of them has changed in Greece. The Albanians came to Greece following the collapse of the Communist bloc at the beginning of the 1990s. Within time it transpired that it was a mass immigration of approximately 500,000 people. Greece was not prepared for such an enormous influx of foreigners and failed to initiate an effective migration policy. The initial reactions of the Greek politicians, media, and society were negative. Social feelings, however, began to turn in the first decade of the XX century. Albanians ceased to be stigmatised as a threat and started to be perceived in a positive way through the prism of the demands of the Greek economy. The economic and migration crisis, however, lead to the reappearance of a xenophobic mood among the Greeks.

  7. Immigration to Greece: a critical evaluation of Greek policy. (United States)

    Lazaridis, G


    "In the light of the EU's interest in the movement of labour within the Union, the first part of this article looks at the character of Greek migrant labour with the aim of providing an overview of changes in the flow of migrant labour into Greece and of the policies adopted in relation to immigrant labour. It discusses the failure of the Greek government to formulate strategic measures to combat illegal immigration...and the limited (if any) efforts being made to aid the integration of Albanians. The second part of the article concentrates on [the experiences of] Albanian migrant labourers in Greece....[It] also assesses the similarities and differences in the employment positions of Albanian men and women in Greece and the way in which mechanisms of marginalisation differently affect these two categories." excerpt

  8. Isotopic evidence for evolution of sub-continental mantle during Red Sea rifting (United States)

    Pallister, John S.; Hegner, Ernst


    Tertiary igneous rocks from near Al Lith, Saudi Arabia are alkaline to subalkaline and bimodal in composition, and document early and late rift volcanism (≥30 Ma to ~20 Ma, 11 Ma and 3 Ma) in the central part of the Red Sea rift. Isotopic and trace-element data from twenty-five samples are presented and used to characterize basalt sources in the early rift.

  9. Malaria in Greece, 1975 to 2010. (United States)

    Vakali, A; Patsoula, E; Spanakos, G; Danis, K; Vassalou, E; Tegos, N; Economopoulou, A; Baka, A; Pavli, A; Koutis, C; Hadjichristodoulou, C; Kremastinou, T


    Malaria, which was endemic in Greece in the past, was officially eliminated in 1974. Since that time and up to 2010, a number of imported cases (ranging from 19 to 76) have been annually reported. The total number of reported laboratory-confirmed cases between 1975 and 2010 was 1,419. Plasmodium falciparum was identified in 628 (44%) of these cases, while P. vivax was found in 524 (37%). Of the total cases, 1,123 (79%) were male (ratio males vs. females: 3.78). Age was only available for 490 cases, of which 352 (72%) belonged to the 18-40 year-age group. Of the 382 malaria cases reported from 1999 to 2010 for which the region/country of acquisition was known, 210 (55%) were from Africa and 142 (37%) from Asia. The massive introduction of economic migrants, in the period from 1990 to 1991 and from 2006 onwards, mainly from countries where malaria is endemic, resulted in the appearance of introduced sporadic cases. In Peloponnese, Central and East Macedonia, Thrace and East Attica, mosquitoes of the genus Anopheles (e.g. Anopheles sacharovi, A. superpictus and A. maculipenis) that can act as plasmodia vectors are abundant and during the summer of 2011, 27 P. vivax cases were reported in Greek citizens residing in the agricultural area of Evrotas in Lakonia and without travel history. As further P. vivax malaria cases occurred in the Lakonia and East Attica areas in 2012, it is becoming urgent to strengthen surveillance and perform integrated mosquito control that will help eliminate the potential risk of malaria reintroduction and reestablishment.

  10. Coals of Greece: distribution, quality and reserves

    Energy Technology Data Exchange (ETDEWEB)

    Koukouzas, C.; Koukouzas, N. [Institute of Geological and Mineral Exploration, Athens (Greece). Dept. of Energy Resources


    Greek coals occur in a number of sedimentary basins and range in age from Eocene to Quaternary. The petrographic data indicate a wide variation in petrographic and chemical composition. The rank ranges from the transition zone peat-lignite to subbituminous. Lignite constitutes the most abundant type of coal in Greece and the most important of the Greek lignite deposits formed during the Pliocene and Pleistocene in shallow lakes and marshes of closed intramontaine basins. The proved lignite reserves are currently estimated at 6750 MT, excluding the 4300 Mm{sup 3} of Philipi peat in Macedonia. There, 58% (about 3900 Mt) is considered to be economically recoverable. The probable and possible reserves are estimated to be of the order of 4000 Mt. The Kozane-Ptolemais-Amynteo-Florian basins in Macedonia contain most (about 64%) of the nation`s coal resources. These lignites, which are all already being exploited, have a very low calorific value (at Ptolemais-Amynteo, 1400 kcal/kg; at Megalopolis, 900 kcal/kg) and high ash and low sulphur contents. The lignite production for 1992 was over 54 Mt. The greatest centres of lignite production are in Macedonia, at the opencast mines of Ptolemais and Amynteo, and in Peloponnesus, at the opencast mine of Negalopolis. The vast majority (98%) of the extracted lignite is used for electricity generation and feeds power plants which have a total capacity of 4533 MW. The lignite-based power plants accounts for more than 72% of the total electricity generation of the country. 19 refs., 6 figs., 2 tabs.

  11. Development of a Coastal Inventory in Greece (United States)

    Karditsa, Aikaterini; Poulos, Serafim; Velegrakis, Adonis; Ghionis, George; Petrakis, Stelios; Alexandrakis, George; Andreadis, Olympos; Monioudi, Isavella


    Greek coastline that accounts more than 16.000 km hosts hundreds of beaches, which constitute a great touristic destination. However, no gathered information exists relative to its qualitative and quantitative characteristics (e.g. physicogeographical characteristics, artificial structures, nearby land use). Therefore, the development of a coastal database that would successfully concentrate all relative data, in the form of a National Inventory, could be a valuable tool for the management and the sustainable use and exploitation of beaches and the coastal zone. This work presents an example of the development of a beach inventory in the case of the beach zones of Heraklion and Lassithi counties in the Island of Crete, which is one of the most touristic areas in Greece. Data were initially abstracted from satellite images and combined with in situ observations carried out along 98 beaches with shoreline length >100 m. The collected data included geomorphological, topographic and bathymetric mapping, sediment sampling from the subaerial and underwater part and recording of artificial structures. The initial mapping showed that beaches represent only the 18%, with 74% of the total coastline to be rocky while 8% of the coastline host some kind of artificial intervention. The combination of satellite and in situ mapping led to the development of a coastal geomorphological map. Beach widths were found to be limited with the majority of beaches (59%) to have maximum widths less than 25 m, 35% to range between 25 and 50m and about 6% with maximum widths >50m. Concerning beach length, the threshold of 1000 m is overcome only by the 46% of the beaches. Beaches with very smooth slopes (Entrepreneurship" co-funded by the European Regional Development Fund (ERDF) and the Ministry of Education and Relegious Affairs.

  12. Aquatic animal resources in Prehistoric Aegean, Greece. (United States)

    Mylona, Dimitra


    This paper explores the early stages in the history of fishing in the Aegean Sea in Greece, and highlights its formative phases and its specific characteristics in different points in time. This is testified by various physical remains, such as fish bones, fishing tools, and representations in art, which are gathered in the course of archaeological research. The aquatic resources in the Aegean Sea have been exploited and managed for millennia by communities that lived near the water and often made a living from it. The earliest evidence for a systematic, intensive exploitation of marine resources in the Aegean Sea dates to the Mesolithic, eleven millennia ago. In the Neolithic period, the adoption of a sedentary, agro-pastoral way of life led to a reduction in the intensity of fishing and shellfish gathering. Its importance as an economic resource remained high only in certain regions of rich, eutrophic waters. In the Bronze Age, an era of social complexity and centralized economy, the exploitation of aquatic, mostly marine, resources became a complex, multi-faceted activity which involved subsistence, industry and ideology. The range of preferred fish and invertebrate species, the fishing technology, and the processing of fish and shellfish in order to produce elaborate foods or prestige items are all traceable aspects of the complex relationship between humans and the aquatic resources throughout the prehistory of fishing and shellfish gathering in the Aegean area. The broadening of collaboration between archaeology and physical sciences offers new means to explore these issues in a more thorough and nuanced manner.

  13. Environmental tobacco smoke in hospitality venues in Greece. (United States)

    Vardavas, Constantine I; Kondilis, Barbara; Travers, Mark J; Petsetaki, Elisabeth; Tountas, Yiannis; Kafatos, Anthony G


    Exposure to environmental tobacco smoke is a major threat to public health. Greece, having the highest smoking prevalence in the European Union is seriously affected by passive smoking. The purpose of this study was to measure environmental tobacco smoke (ETS) exposure in the non smoking areas of hospitality venues and offices in Greece and to compare the levels of exposure to levels in the US, UK and Ireland before and after the implementation of a smoking ban. Experimental measurements of particulate matter 2.5 microm (PM2.5), performed during a cross sectional study of 49 hospitality venues and offices in Athens and Crete, Greece during February - March 2006. Levels of ETS ranged from 19 microg/m3 to 612 microg/m3, differing according to the place of measurement. The average exposure in hospitality venues was 268 microg/m3 with ETS levels found to be highest in restaurants with a mean value of 298 microg/m3 followed by bars and cafes with 271 microg/m3. ETS levels were 76% lower in venues in which smoking was not observed compared to all other venues (p hospitality venues while levels in Ireland with a total smoking ban are 89% lower and smoke-free communities in the US are 91 - 96% lower than levels in Greece. Designated non-smoking areas of hospitality venues in Greece are significantly more polluted with ETS than outdoor air and similar venues in Europe and the United States. The implementation of a total indoor smoking ban in hospitality venues has been shown to have a positive effect on workers and patrons' health. The necessity of such legislation in Greece is thus warranted.

  14. The role of magmatic loads and rift jumps in generating seaward dipping reflectors on volcanic rifted margins (United States)

    Buck, W. Roger


    The largest volcanic constructs on Earth are the seismically imaged seaward dipping reflector (SDR) units found offshore of many rifted continental margins, including most that border the Atlantic Ocean. Whether their formation requires large magnitude (i.e. 10 s of km) of normal fault slip or results from the deflection of the lithosphere by the weight of volcanic flows is controversial. Though there is evidence for faulting associated with some SDRs, this paper considers the range of structures that can be produced by magmatic and volcanic loading alone. To do this an idealized mechanical model for the construction of rift-related volcanic flow structures is developed. Dikes open as plates move away from the center of a model rift and volcanic flows fill the depression produced by the load caused by dike solidification. The thin elastic plate flexure approximation allows a closed form description of the shape of both the contacts between flows and between the flows and underlying dikes. The model depends on two independent parameters: the flexure parameter, α, and the maximum isostatically supported extrusive layer thickness, w0. For reasonable values of these parameters the model reproduces the observed down-dip thickening of flows and the range of reflector dip angles. A numerical scheme using the analytic results allows simulation of the effect of temporal changes in the locus of magmatic spreading as well as changes in the amount of volcanic infill. Either jumps in the location of the center of diking or periods with no volcanism result in separate units or "packages" of model SDRs, in which the flow-dike contact dips landward, consistent with observations previously attributed only to listric normal fault offset. When jumps in the spreading center are small (i.e. less than α) they result in thicker, narrower volcanic units on one side of a rift compared to those on the other side. This is similar to the asymmetric distributions of volcanic packages seen

  15. The regional structure of the Red Sea Rift revised (United States)

    Augustin, Nico; van der Zwan, Froukje M.; Devey, Colin W.; Brandsdóttir, Bryndís


    The Red Sea Rift has, for decades, been considered a text book example of how young ocean basins form and mature. Nevertheless, most studies of submarine processes in the Red Sea were previously based on sparse data (mostly obtained between the late 1960's and 1980's) collected at very low resolution. This low resolution, combined with large gaps between individual datasets, required large interpolations when developing geological models. Thus, these models generally considered the Red Sea Rift a special case of young ocean basement formation, dividing it from North to South into three zones: a continental thinning zone, a "transition zone" and a fully developed spreading zone. All these zones are imagined, in most of the models, to be separated by large transform faults, potentially starting and ending on the African and Arabian continental shields. However, no consensus between models e.g. about the locations (or even the existence) of major faults, the nature of the transition zone or the extent of oceanic crust in the Red Sea Rift has been reached. Recently, high resolution bathymetry revealed detailed seafloor morphology as never seen before from the Red Sea, very comparable to other (ultra)slow spreading mid-ocean ridges such as the Gakkel Ridge, the Mid-Atlantic Ridge and SW-Indian Ridge, changing the overall picture of the Red Sea significantly. New discoveries about the extent, movement and physical properties of submarine salt deposits led to the Red Sea Rift being linked to the young Aptian-age South Atlantic. Extensive crosscutting transform faults are not evident in the modern bathymetry data, neither in teleseismic nor vertical gravity gradient data and comparisons to Gakkel Ridge and the SW-Indian Ridge suggest that the Red Sea is much simpler in terms of structural geology than was previously thought. Complicated tectonic models do not appear necessary and there appears to be large areas of oceanic crust under the Red Sea salt blankets. Based on

  16. Polyphase Rifting and Breakup of the Central Mozambique Margin (United States)

    Senkans, Andrew; Leroy, Sylvie; d'Acremont, Elia; Castilla, Raymi


    The breakup of the Gondwana supercontinent resulted in the formation of the Central Mozambique passive margin as Africa and Antarctica were separated during the mid-Jurassic period. The identification of magnetic anomalies in the Mozambique Basin and Riiser Larsen Sea means that post-oceanisation plate kinematics are well-constrained. Unresolved questions remain, however, regarding the initial fit, continental breakup process, and the first relative movements of Africa and Antarctica. This study uses high quality multi-channel seismic reflection profiles in an effort to identify the major crustal domains in the Angoche and Beira regions of the Central Mozambique margin. This work is part of the integrated pluri-disciplinary PAMELA project*. Our results show that the Central Mozambique passive margin is characterised by intense but localised magmatic activity, evidenced by the existence of seaward dipping reflectors (SDR) in the Angoche region, as well as magmatic sills and volcanoclastic material which mark the Beira High. The Angoche region is defined by a faulted upper-continental crust, with the possible exhumation of lower crustal material forming an extended ocean-continent transition (OCT). The profiles studied across the Beira high reveal an offshore continental fragment, which is overlain by a pre-rift sedimentary unit likely to belong to the Karoo Group. Faulting of the crust and overlying sedimentary unit reveals that the Beira High has recorded several phases of deformation. The combination of our seismic interpretation with existing geophysical and geological results have allowed us to propose a breakup model which supports the idea that the Central Mozambique margin was affected by polyphase rifting. The analysis of both along-dip and along-strike profiles shows that the Beira High initially experienced extension in a direction approximately parallel to the Mozambique coastline onshore of the Beira High. Our results suggest that the Beira High results

  17. Postspreading rifting in the Adare Basin, Antarctica: Regional tectonic consequences (United States)

    Granot, R.; Cande, S. C.; Stock, J. M.; Davey, F. J.; Clayton, R. W.


    Extension during the middle Cenozoic (43-26 Ma) in the north end of the West Antarctic rift system (WARS) is well constrained by seafloor magnetic anomalies formed at the extinct Adare spreading axis. Kinematic solutions for this time interval suggest a southward decrease in relative motion between East and West Antarctica. Here we present multichannel seismic reflection and seafloor mapping data acquired within and near the Adare Basin on a recent geophysical cruise. We have traced the ANTOSTRAT seismic stratigraphic framework from the northwest Ross Sea into the Adare Basin, verified and tied to DSDP drill sites 273 and 274. Our results reveal three distinct periods of tectonic activity. An early localized deformational event took place close to the cessation of seafloor spreading in the Adare Basin (˜24 Ma). It reactivated a few normal faults and initiated the formation of the Adare Trough. A prominent pulse of rifting in the early Miocene (˜17 Ma) resulted in normal faulting that initiated tilted blocks. The overall trend of structures was NE-SW, linking the event with the activity outside the basin. It resulted in major uplift of the Adare Trough and marks the last extensional phase of the Adare Basin. Recent volcanic vents (Pliocene to present day) tend to align with the early Miocene structures and the on-land Hallett volcanic province. This latest phase of tectonic activity also involves near-vertical normal faulting (still active in places) with negligible horizontal consequences. The early Miocene extensional event found within the Adare Basin does not require a change in the relative motion between East and West Antarctica. However, the lack of subsequent rifting within the Adare Basin coupled with the formation of the Terror Rift and an on-land and subice extension within the WARS require a pronounced change in the kinematics of the rift. These observations indicate that extension increased southward, therefore suggesting that a major change in

  18. From continental to oceanic rifting in the Gulf of California (United States)

    Ferrari, Luca; Bonini, Marco; Martín, Arturo


    The continental margin of northwestern Mexico is the youngest example of the transition from a convergent plate boundary to an oblique divergent margin that formed the Gulf of California rift. Subduction of the Farallon oceanic plate during the Cenozoic progressively brought the East Pacific Rise (EPR) toward the North America trench. In this process increasingly younger and buoyant oceanic lithosphere entered the subduction zone until subduction ended just before most of the EPR could collide with the North America continental lithosphere. The EPR segments bounding the unsubducted parts of the Farallón plate remnants (Guadalupe and Magdalena microplates) also ceased spreading (Lonsdale, 1991) and a belt of the North American plate (California and Baja California Peninsula) became coupled with the Pacific Plate and started moving northwestward forming the modern Gulf of California oblique rift (Nicholson et al., 1994; Bohannon and Parsons, 1995). The timing of the change from plate convergence to oblique divergence off western Mexico has been constrained at the middle Miocene (15-12.5 Ma) by ocean floor morphology and magnetic anomalies as well as plate tectonic reconstructions (Atwater and Severinghaus, 1989; Stock and Hodges, 1989; Lonsdale, 1991), although the onset of transtensional deformation and the amount of right lateral displacement within the Gulf region are still being studied (Oskin et al., 2001; Fletcher et al., 2007; Bennett and Oskin, 2014). Other aspects of the formation of the Gulf of California remain not well understood. At present the Gulf of California straddles the transition from continental transtension in the north to oceanic spreading in the south. Seismic reflection-refraction data indicate asymmetric continent-ocean transition across conjugate margins of rift segments (González-Fernández et al., 2005; Lizarralde et al., 2007; Miller and Lizarralde, 2013; Martín-Barajas et al., 2013). The asymmetry may be related to crustal

  19. The Miocene carnivore assemblage of Greece

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    Koufos, G. D.


    Full Text Available The Miocene carnivore assemblage of Greece includes a great number of taxa, described in numerous articles since the first decades of the 19th Century. The present article is a revision of all these taxa, providing information about their history, localities, age, as well as their stratigraphic distribution and palaeoenvironment. The Early/Middle Miocene carnivore record of Greece is poor as the available fossiliferous sites and material are rare. However, the Late Miocene one is quite rich, including numerous taxa. The Miocene localities with carnivores and their age are given in a stratigraphic table covering the European Mammal zones from MN 4 to MN 13. The type locality, holotype, and some historical and morphological remarks are given for each taxon. Several carnivore taxa were erected from Greek material and new photos of their holotypes are given. The stratigraphic distribution of the Greek carnivore taxa indicates that they are covering the time span from ~19.0-5.3Ma. The majority of the Miocene taxa (Adcrocuta, Hyaenictitherium, Plioviverrops, Protictitherium, Ictitherium, Indarctos, Dinocrocuta, Promephitis disappeared at the end of Miocene. The composition of the Early/Middle Miocene carnivore assemblage of Greece includes mainly viverrids (Lophocyon, Euboictis, while the hyaenids, percrocutids, felids and mustelids are very few. On the contrary the Late Miocene assemblage is richer, including more subfamilies and species; the hyaenids and mustelids dominate, while the viverrids are absent. The Late Miocene carnivore guild structure is similar to that of the modern Serengeti, indicating a relatively open, savannah-like environment.

    La asociación de carnívoros miocenos de Grecia incluye un gran número de taxones, descritos en numerosos artículos desde las primeras décadas del siglo XIX. El presente artículo supone un esfuerzo de síntesis de todos estos taxones, suministrando información sobre su

  20. Aid for the victims of the forest fires in Greece

    CERN Multimedia


    To support the victims of the fires which devastated the Peloponnese at the end of August, the Permanent Mission of Greece in Geneva has informed us that the Greek government has opened an account into which donations may be paid. The funds collected will be used to assist the many victims of these fires. Bank of Greece Account name: Logariasmos Arogis Pyropathon (Hellenic Republic) (account reserved for aid for the victims of the forest fires) SWIFT : BNGRGRAA IBAN : GR 98 0100 0230 0000 0234 1103 053

  1. Motion in the north Iceland volcanic rift zone accommodated by bookshelf faulting (United States)

    Green, Robert G.; White, Robert S.; Greenfield, Tim


    Along mid-ocean ridges the extending crust is segmented on length scales of 10-1,000km. Where rift segments are offset from one another, motion between segments is accommodated by transform faults that are oriented orthogonally to the main rift axis. Where segments overlap, non-transform offsets with a variety of geometries accommodate shear motions. Here we use micro-seismic data to analyse the geometries of faults at two overlapping rift segments exposed on land in north Iceland. Between the rift segments, we identify a series of faults that are aligned sub-parallel to the orientation of the main rift. These faults slip through left-lateral strike-slip motion. Yet, movement between the overlapping rift segments is through right-lateral motion. Together, these motions induce a clockwise rotation of the faults and intervening crustal blocks in a motion that is consistent with a bookshelf-faulting mechanism, named after its resemblance to a tilting row of books on a shelf. The faults probably reactivated existing crustal weaknesses, such as dyke intrusions, that were originally oriented parallel to the main rift and have since rotated about 15° clockwise. Reactivation of pre-existing, rift-parallel weaknesses contrasts with typical mid-ocean ridge transform faults and is an important illustration of a non-transform offset accommodating shear motion between overlapping rift segments.

  2. Analysis of the pre-rift/rifte transition interval (Serraria and Barra de Itiuba formations) from the Sergipe-Alagoas basin; Analise da secao de transicao pre-rifte/rifte (formacoes Serraria e Barra de Itiuba) da Bacia Sergipe-Alagoas

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    Barreiro, C.B.; Mizusaki, A.M.P. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)]. E-mail:;; Garcia, A.J.V. [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)]. E-mail:


    The pre-rift/rift transition is represented by the Serraria and Barra de Itiuba formations. This interval was analyzed through qualitative and quantitative descriptions of cores, electric log analysis and studies of outcropping sections. The integration of surface and subsurface data allowed the stratigraphic characterization of sandstone bodies in the pre-rift/rift. These sandstones bodies were deposited by fluvial braided, lacustrine and deltaic systems (delta plain, delta front and pro delta). The sedimentary deposits characterized in the Serraria Formation are of channel, flooding of the fluvial system and eolic. The upper interval of this formation is characterized by to coarse medium-grained sandstones identified as the Caioba Sandstone. The Barra de Itiuba Formation contains lake, pro delta, frontal bar, distributary mouth, crevasse and distributary channel deposits. The sandstone units were specifically characterized in terms of their potential reservoir quality, and they were characterized the reservoirs R1 (good to medium quality) and Caioba (good quality) from the pre-rift phase, and reservoirs R2 (medium quality) and R3 (medium to good quality) from the rift phase. The reservoirs from pre-rift phase phase show the better reservoirs quality potential of the pre-rift/rift transition in the Sergipe-Alagoas Basin. (author)

  3. High Fluoride and Geothermal Activities In Continental Rift Zones, Ethiopia (United States)

    Weldesenbet, S. F.; Wohnlich, S.


    The Central Main Ethiopian Rift basin is a continental rift system characterized by volcano-tectonic depression endowed with huge geothermal resource and associated natural geochemical changes on groundwater quality. Chemical composition of groundwater in the study area showed a well defined trend along flow from the highland and escarpment to the rift floor aquifer. The low TDS (water at recharge area in the highlands and escarpments evolve progressively into Ca-Na-HCO3 and Na-Ca-HCO3 type waters along the rift ward groundwater flow paths. These waters finally appear as moderate TDS (mean 960mg/l) Na-HCO3 type and as high TDS (> 1000 mg/l) Na-HCO3-Cl type in volcano-lacustrine aquifers of the rift floor. High concentrations of fluoride (up to 97.2 mg/l) and arsenic (up to 98μg/l) are recognized feature of groundwaters which occur mostly in the vicinity of the geothermal fields and the rift lakes in the basin. Fluoride and arsenic content of dry volcaniclastic sediments close to these areas are in the range 666-2586mg/kg and 10-13mg/kg respectively. The relationship between fluoride and calcium concentrations in groundwaters showed negative correlation. Near-equilibrium state attained between the mineral fluorite (CaF2) and the majority of fluoride-rich (>30mg/l) thermal groundwater and shallow cold groundwater. This indicated that the equilibrium condition control the high concentration of fluoride in the groundwaters. Whereas undersaturation state of fluorite in some relatively low-fluoride (waters indicated a dilution by cold waters. Laboratory batch leaching experiments showed that fast dissolution of fluoride from the sediment samples suddenly leached into the interacting water at the first one hour and then remain stable throughout the experiment. The concentrations of leached fluoride from the hot spring deposits, the lacustrine sediments, and the pyroclastic rock are usually low (1% of the total or less than the content in the sediment or rock) but

  4. Fluoride and Geothermal Activities In Continental Rift Zones, Ethiopia (United States)

    Weldesenbet, S. F.


    The Central Main Ethiopian Rift basin is a continental rift system characterized by volcano-tectonic depression endowed with huge geothermal resource and associated natural geochemical changes on groundwater quality. Chemical composition of groundwater in the study area showed a well defined trend along flow from the highland and escarpment to the rift floor aquifer. The low TDS (water at recharge area in the highlands and escarpments evolve progressively into Ca-Na-HCO3 and Na-Ca-HCO3 type waters along the rift ward groundwater flow paths. These waters finally appear as moderate TDS (mean 960mg/l) Na-HCO3 type and as high TDS (> 1000 mg/l) Na-HCO3-Cl type in volcano-lacustrine aquifers of the rift floor. High concentrations of fluoride (up to 97.2 mg/l) and arsenic (up to 98μg/l) are recognized feature of groundwaters which occur mostly in the vicinity of the geothermal fields and the rift lakes in the basin. Fluoride and arsenic content of dry volcaniclastic sediments close to these areas are in the range 666-2586mg/kg and 10-13mg/kg respectively. The relationship between fluoride and calcium concentrations in groundwaters showed negative correlation. Near-equilibrium state attained between the mineral fluorite (CaF2) and the majority of fluoride-rich (>30mg/l) thermal groundwater and shallow cold groundwater. This indicated that the equilibrium condition control the high concentration of fluoride in the groundwaters. Whereas undersaturation state of fluorite in some relatively low-fluoride (waters indicated a dilution by cold waters. Laboratory batch leaching experiments showed that fast dissolution of fluoride from the sediment samples suddenly leached into the interacting water at the first one hour and then remain stable throughout the experiment. The concentrations of leached fluoride from the hot spring deposits, the lacustrine sediments, and the pyroclastic rock are usually low (1% of the total or less than the content in the sediment or rock) but


    Directory of Open Access Journals (Sweden)



    Full Text Available The geographical distribution of the birch (BeTula pendula Roth. in Greece is Limited to the northern mountains (Varnous, Voras, Vennio, Paiko, Beles, Orvilos, Lailias, Pangeo, Phalakro and Rhooope. The unique extensive pure Betula penduta - forest, which covers an area of about 1755 ha, occurs in the western part of the Rhodope mountain range. The other appearances of birch in the Greek area are limited either to small stands or to individuals in mixture with other forest trees. The Betula pendula forest in western Rhodope have been studied using the Braun - B1anquet mtethod with 36 phytosociological relevés. Two associations. Querco dalechampii - Betuletum pendulae (Quercetalia pubescentis and Fago sylvalicae - Betuletum pendulae (Fagetali sylvAticae , as well as rurther subdivisions, are distinguished. Their syntaxonomy as well as informatìon about the site characteristics, structure and syndynamical position of the distinguished communities are given.

  6. How sedimentation affects rift segment interaction during oblique extension: a 4D analogue modelling study (United States)

    Zwaan, Frank; Schreurs, Guido; Adam, Jürgen


    During the early stages of rifting, rift segments may form along non-continuous and/or offset pre-existing weaknesses. It is important to understand how these initial rift segments interact and connect to form a continuous rift system. Previous modelling of rift interaction structures has shown the dominant influence of oblique extension, promoting rift segment linkage (e.g. Zwaan et al., 2016) and eventual continent break-up (Brune et al., 2012). However, these studies did not incorporate sedimentation, which can have important implications for rift evolution (e.g. Bialas and Buck, 2009). Here we present a series of analogue model experiments investigating the influence of sedimentation on rift interaction structures under oblique extension conditions. Our set-up involves a base of compressed foam and plexiglass that forces distributed extension in the overlying analogue materials when the model sidewalls move apart. A sand layer simulates the brittle upper crust and a viscous sand/silicone mixture the ductile lower crust. One of the underlying base plates can move laterally allowing oblique extension. Right-stepping offset and disconnected lines of silicone (seeds) on top of the basal viscous serve as inherited structures since the strong sand cover is locally thinner. We apply syn-rift sediments by filling in the developing rift and transfer zone basins with sand at fixed time steps. Models are run either with sedimentation or without to allow comparison. The first results suggest that the gross structures are similar with or without sedimentation. As seen by Zwaan et al. (2016), dextral oblique extension promotes rift linkage because rift propagation aligns itself perpendicular to the extension direction. This causes the rift segments to grow towards each other and to establish a continuous rift structure. However, the structures within the rift segments show quite different behaviour when sedimentation is applied. The extra sediment loading in the rift basin

  7. Influence of rifting episodes on seismic and volcanic activity in the southern Red Sea region (United States)

    Viltres, Renier; Ruch, Joël; Doubre, Cécile; Reilinger, Rob; Ogubazghi, Ghebrebrhan; Jónsson, Sigurjón


    Rifting episodes cause large changes to the state of stress in the surrounding crust, both instantaneously (elastic stress transfer) and in the years following the episodes (viscoelastic stress transfer), and can significantly influence occurrence of future earthquakes and volcanic eruptions. Here we report on a new project that aims at studying the stress impact of rifting episodes and focuses on the southern Red Sea, Afar and Gulf of Aden region, which has seen a significant increase in rifting activity during the past decade. The Afar rift system experienced a major rifting episode (Dabbahu segment) in 2005-2010 and the southern Red Sea also appears to have had one, indicated by three volcanic eruptions in 2007, 2011-12, and 2013 (the first in the area in over a century), accompanied by several seismic swarms. In addition, Gulf of Aden had an exceptionally strong seismic swarm activity starting in late 2010 that was associated with intrusion of magma in a separate rifting episode. To explore the influence of these recent rifting episodes in the region we will use new geodetic observations, seismicity analysis and modeling. We have analyzed new GPS data collected in Eritrea, in Afar, and in southern Saudi Arabia. Comparisons with older surveys has not only resulted in better GPS velocities for the observed sites, but also revealed changes to velocities at some sites influenced by the rifting activity. We use the results along with seismic data to better constrain the timing, magnitude and duration of the rifting activity in the region. We will then apply elastic and visco-elastic stress transfer modeling to assess the associated stress changes, in particular at locations where volcanic eruptions or intrusions have occurred or where significant seismicity has been detected. The project should provide new information about the impact rifting events and episodes can have on regional volcanic and earthquake activity and how rifting episodes may influence one another.

  8. Occupational Dermatoses by Type of Work in Greece

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    Eleni Zorba


    Conclusion: Prevalence of ODs is high in Greece, contrary to all official reports by the Greek National Institute of Health. There is a need to introduce a nationwide voluntary surveillance system for reporting ODs and to enhance skin protection measures at work.

  9. Plato and Play: Taking Education Seriously in Ancient Greece (United States)

    D'Angour, Armand


    In this article, the author outlines Plato's notions of play in ancient Greek culture and shows how the philosopher's views on play can be best appreciated against the background of shifting meanings and evaluations of play in classical Greece. Play--in various forms such as word play, ritual, and music--proved central to the development of…

  10. Public investment and regional growth and convergence : Evidence from Greece

    NARCIS (Netherlands)

    Rodriguez-Pose, Andres; Psycharis, Yannis; Tselios, Vassilis

    This paper estimates the impact of public investment on regional economic growth and convergence at the NUTS 3 level in Greece. Using a new database of public expenditure per region for the period 19782007, it proposes a model which captures not just the impact of public investment in Greek

  11. Lessons from Greece: A Body, Mind, Spirit Odyssey (United States)

    Lyman, Linda L.


    In Spring Semester 2005, the author was a visiting Fulbright professor at Aristotle University in Greece. The purpose of the Fulbright Program is to increase mutual understanding between the people of the United States and the people of the 150 or so countries that currently participate in the Fulbright Program. In this article, the author looks…

  12. Understanding Curriculum Change in an ELT School in Greece (United States)

    Kostoulas, Achilleas; Stelma, Juup


    This article reports on a case study of a language school in Greece, with a view to putting forward an understanding of the drivers that sustain or delay curricular innovation. Key to this understanding is the construct of intentionality, defined as "purposes" that drive teaching and learning activity. In the article, we describe three…

  13. Knowledge and attitude towards smoking of pregnant women in Greece

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    Athina Diamanti


    Having not being informed and helped adequately, a significant percentage of pregnant women continued to smoke throughout their pregnancy. The failure in imposing the clean indoor air law in public places in Greece has also contributed to the increased passive smoking exposure.

  14. A new Leiobunum species from Greece (Arachnida, Opiliones, Phalangiidae)

    NARCIS (Netherlands)

    Karaman, Ivo M.


    Leiobunum gruberi nov. spec. (Arachnida, Opiliones, Phalangiidae) from northern Greece (Macedonia, Leptokaria) is described and figured. This species is closely related to Leiobunum seriatum Simon, 1878, known from the Near East, Cyprus and eastern Anatolia. A short review of known taxa of the genus

  15. Gender Equality in Employment Utilizing Female Social Entrepreneurship in Greece

    NARCIS (Netherlands)

    Argyrou, A.; Charitakis, Stelios


    Greek women are severely affected by the on-going financial crisis. They deal with the effects of unemployment and they experience a marginalised position in the Greek labour market due to deep-rooted stereotypes which result in inequality of employment opportunities. Greece has ratified the CEDAW

  16. Energy policies of IEA countries: Greece 2006 review

    Energy Technology Data Exchange (ETDEWEB)



    The report provides an in-depth assessment of the energy policies of Greece and makes recommendations on future policy. Lignite, the main domestic fossil fuel resource of Greece, will continue to play a major role in the country's fuel mix in the future. The government and the regulator should consider introducing more advanced generation technology through retrofits or into new lignite power stations. It may be an option to construct a power station using lignite from unopened deposits, for the exploitation of which a new bidding procedure is currently open. Since the previous review in 2002, Greece has also made significant progress in setting the course for reforming its electricity and gas markets. Energy diversification has improved, with natural gas becoming increasingly important. Significant challenges, however, remain. The market power of the incumbent energy suppliers continues to restrict competition. Unless this issue is addressed, a fully competitive energy market is inconceivable. Of particular concern are the arrangements for ownership of the electricity and gas transmission systems. The review suggests various options to overcome these obstacles. Greece is getting close to missing its target set under the Kyoto Protocol and the government is urged to closely monitor the situation. The supply and demand situation is addressed.. Recommendations are made on how to reduce the country's high oil dependence and advice offered to policy makers on steps to develop a long-term energy efficiency policy with measurable targets that tackle the demand side of the Greek energy sector.

  17. Academic Entrepreneurship, Innovation Policies and Politics in Greece (United States)

    Arapostathis, Stathis


    This paper explores the process of the emergence in Greece of the "Triple Helix", and the nature of the "Helix" in the context of the concurrent changes occurring in Greek socio-political affairs. The influence of politics and innovation policies on the relationships between academia and government and industry is considered.…

  18. Vocational Training in the Textiles and Clothing Industries in Greece. (United States)

    Drimousis, I.; Zisimopoulos, A.

    This document examines the circumstances under which vocational training in Greece is provided for jobs in the textile and clothing industries. Its objective is to identify guidelines for vocational training for a skilled work force at regional and national levels and to contribute to job mobility between industries. Statistical data,…

  19. School Psychology in Greece: A System of Change. (United States)

    Theodore, Lea A.; Bray, Melissa A.; Kehle, Thomas J.; Dioguardi, Richard J.


    Discusses origin of school psychology in Greece which emerged with services for mentally disabled in 1937. Explains how laws were instituted with the growing demand for educational services for students with social and emotional needs. Includes discussions on diverse roles of school psychologists, present status of special education, and influence…

  20. Implementing Innovation in Primary EFL: A Case Study in Greece (United States)

    Karavas, Evdokia


    The purpose of this article is to highlight and discuss the strategies used to diffuse and manage a primary ELT innovation in Greece, strategies that proved essential for developing stakeholders' acceptance and ownership of the innovation, thereby facilitating its further development and sustainability. The PEAP Programme, launched in 2010,…

  1. Plant communities on metalliferous soils in northern Greece

    NARCIS (Netherlands)

    Bergmeier, E.; Konstantinou, M.; Tsiripidis, I.; Sykora, K.V.


    We studied dry stony habitats with metalliferous soils (with various amounts of Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) at low to moderate altitudes in 22 localities in northern Greece using 193 original phytosociological relevés with vascular species composition, species abundance and topographical data.

  2. Psychometric Validation of the Youth Social Capital Scale in Greece (United States)

    Koutra, Kleio; Orfanos, Philippos; Roumeliotaki, Theano; Kritsotakis, George; Kokkevi, Anna; Philalithis, Anastasios


    Objectives: This article describes the psychometric validation of the Youth Social Capital scale (YSCS) in 16- to 17-year-old students living in rural and urban areas in Crete, Greece. Methods: Sampling was performed among 27 secondary education units of Heraklion Prefecture. The self-reported questionnaire was answered by 692 participants…

  3. An assessment of the environmental education in Greece ...

    African Journals Online (AJOL)

    This study briefly reviews the Environmental Education (EE) in Greece, examines the teachers' training and participation in E.E. programs as well as the realization and allocation of these programs in secondary education. It also analyzes facilities availability in schools and the factors, which encourage or discourage ...

  4. Reconstruction of the paleo-coastline of Santorini island (Greece ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 1. Reconstruction of the paleo-coastline of Santorini island (Greece), after the 1613 BC volcanic eruption: A GIS-based quantitative methodology. Dimitrios Oikonomidis Konstantinos Albanakis Spyridon Pavlides Michael Fytikas. Volume 125 Issue 1 ...

  5. Pedagogical Beliefs and Attitudes of Computer Science Teachers in Greece (United States)

    Fessakis, Georgios; Karakiza, Tsampika


    Pedagogical beliefs and attitudes significantly determine the professional skills and practice of teachers. Many professional development programs for teachers aim to the elaboration of the pedagogical knowledge in order to improve teaching quality. This paper presents the study of pedagogical beliefs of computer science teachers in Greece. The…

  6. Secondary Education in Greece. Guide to Secondary Education in Europe. (United States)

    Kallen, Denis

    Cultural and national history have profoundly modeled Greek society and continue to play a vital role in Greek policy and in cultural and social life. This handbook provides a brief overview of secondary education in Greece. The first part describes the country's societal, historical, and political background; educational history and current…

  7. Changing Patterns of Finance in Higher Education. Country Study: Greece. (United States)

    Soumelis, Constantin

    The report examines trends and issues concerned with the financing of higher education in Greece from 1974 to 1988. Greek higher education, which is almost all public, has expanded at an average annual rate of 3% during the period with the non-university technical component growing at an annual rate of 17.8%. Though the expansion was facilitated…

  8. Geranium kikianum sp nov (Geraniaceae) from the southern Peloponnese, Greece

    DEFF Research Database (Denmark)

    Tan, K.; Siljak-Yakovlev, S.; Vold, G.


    Geranium kikianum Kit Tan & G. Vold sp. nov. (Geraniaceae) is illustrated and described as a new species endemic to Greece. It occurs beside streams and other wet places in open Pinus nigra forest at the foothills of Mt Taigetos in the southern Peloponnese. It is closely related to G. macrorrhizum...

  9. Let's Play Doctor: Medical Rounds in Ancient Greece. (United States)

    Bockler, Donald


    Biology students are exposed to historical theories of medicine by contrasting modern medicine and germ theory with the humoral theory of medicine in ancient Greece. After spending one day describing basic theories in humoral medicine, the teacher role-plays a Hippocratic physician treating ailing Greek patients in a Hippocratic medical workshop.…

  10. Post-rift deformation of the Red Sea Arabian margin (United States)

    Zanoni, Davide; Schettino, Antonio; Pierantoni, Pietro Paolo; Rasul, Najeeb


    Starting from the Oligocene, the Red Sea rift nucleated within the composite Neoproterozoic Arabian-Nubian shield. After about 30 Ma-long history of continental lithosphere thinning and magmatism, the first pulse of oceanic spreading occurred at around 4.6 Ma at the triple junction of Africa, Arabia, and Danakil plate boundaries and propagated southward separating Danakil and Arabia plates. Ocean floor spreading between Arabia and Africa started later, at about 3 Ma and propagated northward (Schettino et al., 2016). Nowadays the northern part of the Red Sea is characterised by isolated oceanic deeps or a thinned continental lithosphere. Here we investigate the deformation of thinned continental margins that develops as a consequence of the continental lithosphere break-up induced by the progressive oceanisation. This deformation consists of a system of transcurrent and reverse faults that accommodate the anelastic relaxation of the extended margins. Inversion and shortening tectonics along the rifted margins as a consequence of the formation of a new segment of ocean ridge was already documented in the Atlantic margin of North America (e.g. Schlische et al. 2003). We present preliminary structural data obtained along the north-central portion of the Arabian rifted margin of the Red Sea. We explored NE-SW trending lineaments within the Arabian margin that are the inland continuation of transform boundaries between segments of the oceanic ridge. We found brittle fault zones whose kinematics is consistent with a post-rift inversion. Along the southernmost transcurrent fault (Ad Damm fault) of the central portion of the Red Sea we found evidence of dextral movement. Along the northernmost transcurrent fault, which intersects the Harrat Lunayyir, structures indicate dextral movement. At the inland termination of this fault the evidence of dextral movement are weaker and NW-SE trending reverse faults outcrop. Between these two faults we found other dextral transcurrent

  11. Stress perturbation associated with the Amazonas and other ancient continental rifts (United States)

    Zoback, M.L.; Richardson, R.M.


    The state of stress in the vicinity of old continental rifts is examined to investigate the possibility that crustal structure associated with ancient rifts (specifically a dense rift pillow in the lower crust) may modify substantially the regional stress field. Both shallow (2.0-2.6 km depth) breakout data and deep (20-45 km depth) crustal earthquake focal mechanisms indicate a N to NNE maximum horizontal compression in the vicinity of the Paleozoic Amazonas rift in central Brazil. This compressive stress direction is nearly perpendicular to the rift structure and represents a ???75?? rotation relative to a regional E-W compressive stress direction in the South American plate. Elastic two-dimensional finite element models of the density structure associated with the Amazonas rift (as inferred from independent gravity modeling) indicate that elastic support of this dense feature would generate horizontal rift-normal compressional stresses between 60 and 120 MPa, with values of 80-100 MPa probably most representative of the overall structure. The observed ???75?? stress rotation constrains the ratio of the regional horizontal stress difference to the rift-normal compressive stress to be between 0.25 and 1.0, suggesting that this rift-normal stress may be from 1 to 4 times larger than the regional horizontal stress difference. A general expression for the modification of the normalized local horizontal shear stress (relative to the regional horizontal shear stress) shows that the same ratio of the rift-normal compression relative to the regional horizontal stress difference, which controls the amount of stress rotation, also determines whether the superposed stress increases or decreases the local maximum horizontal shear stress. The potential for fault reactivation of ancient continental rifts in general is analyzed considering both the local stress rotation and modification of horizontal shear stress for both thrust and strike-slip stress regimes. In the Amazonas

  12. Lithology and temperature: How key mantle variables control rift volcanism (United States)

    Shorttle, O.; Hoggard, M.; Matthews, S.; Maclennan, J.


    Continental rifting is often associated with extensive magmatic activity, emplacing millions of cubic kilometres of basalt and triggering environmental change. The lasting geological record of this volcanic catastrophism are the large igneous provinces found at the margins of many continents and abrupt extinctions in the fossil record, most strikingly that found at the Permo-Triassic boundary. Rather than being considered purely a passive plate tectonic phenomenon, these episodes are frequently explained by the involvement of mantle plumes, upwellings of mantle rock made buoyant by their high temperatures. However, there has been debate over the relative role of the mantle's temperature and composition in generating the large volumes of magma involved in rift and intra-plate volcanism, and even when the mantle is inferred to be hot, this has been variously attributed to mantle plumes or continental insulation effects. To help resolve these uncertainties we have combined geochemical, geophysical and modelling results in a two stage approach: Firstly, we have investigated how mantle composition and temperature contribute to melting beneath Iceland, the present day manifestation of the mantle plume implicated in the 54Ma break up of the North Atlantic. By considering both the igneous crustal production on Iceland and the chemistry of its basalts we have been able to place stringent constraints on the viable temperature and lithology of the Icelandic mantle. Although a >100°C excess temperature is required to generate Iceland's thick igneous crust, geochemistry also indicates that pyroxenite comprises 10% of its source. Therefore, the dynamics of rifting on Iceland are modulated both by thermal and compositional mantle anomalies. Secondly, we have performed a global assessment of the mantle's post break-up thermal history to determine the amplitude and longevity of continental insulation in driving excess volcanism. Using seismically constrained igneous crustal

  13. Molecular Epidemiology and Emergence of Rift Valley Fever

    Directory of Open Access Journals (Sweden)

    Sall AA


    Full Text Available Rift Valley fever (RVF is a mosquito-borne viral disease which manifested itself during recent epidemics and revealed its significant potential of emergence. Studies on molecular epidemiology undertaken to better understand the factors leading to RVF emergence, have confirmed the mode of circulation of the virus and highlithted probable risks and obstacles for prevention and control. As for several other viral agents, molecular epidemiology is becoming a useful tool in the study of the emergence of RVF as a serious infectious disease.

  14. Environmental tobacco smoke in hospitality venues in Greece

    Directory of Open Access Journals (Sweden)

    Tountas Yiannis


    Full Text Available Abstract Background Exposure to environmental tobacco smoke is a major threat to public health. Greece, having the highest smoking prevalence in the European Union is seriously affected by passive smoking. The purpose of this study was to measure environmental tobacco smoke (ETS exposure in the non smoking areas of hospitality venues and offices in Greece and to compare the levels of exposure to levels in the US, UK and Ireland before and after the implementation of a smoking ban. Methods Experimental measurements of particulate matter 2.5 μm (PM2.5, performed during a cross sectional study of 49 hospitality venues and offices in Athens and Crete, Greece during February – March 2006. Results Levels of ETS ranged from 19 μg/m3 to 612 μg/m3, differing according to the place of measurement. The average exposure in hospitality venues was 268 μg/m3 with ETS levels found to be highest in restaurants with a mean value of 298 μg/m3 followed by bars and cafes with 271 μg/m3. ETS levels were 76% lower in venues in which smoking was not observed compared to all other venues (p Conclusion Designated non-smoking areas of hospitality venues in Greece are significantly more polluted with ETS than outdoor air and similar venues in Europe and the United States. The implementation of a total indoor smoking ban in hospitality venues has been shown to have a positive effect on workers and patrons' health. The necessity of such legislation in Greece is thus warranted.

  15. Magmatism on rift flanks : Insights from ambient noise phase velocity in Afar region

    NARCIS (Netherlands)

    Korostelev, F.; Weemstra, C.; Leroy, S.; Boschi, L.; Keir, D.; Ren, Y.; Molinari, I.; Ahmed, A.; Stuart, G.W.; Rolandone, F.; Khanbari, K.; Hammond, J.O.S.; Kendall, M.K.; Doubre, C.; Al Ganad, I.; Goitom, B.; Ayele, A.


    During the breakup of continents in magmatic settings, the extension of the rift valley is commonly assumed to initially occur by border faulting and progressively migrate in space and time toward the spreading axis. Magmatic processes near the rift flanks are commonly ignored. We present phase

  16. Permo-Triassic intraplate magmatism and rifting in Eurasia: implications for mantle dynamics.

    NARCIS (Netherlands)

    Nikishin, A.M.; Ziegler, P.A.; Abbott, D.; Brunet, M.F.; Cloetingh, S.A.P.L.


    At the transition from the Permian to the Triassic, Eurasia was the site of voluminous flood-basalt extrusion and rifting. Major flood-basalt provinces occur in the Tunguska, Taymyr, Kuznetsk, Verkhoyansk - Vilyuy and Pechora areas, as well as in the South Chinese Emeishen area. Contemporaneous rift

  17. Crustal structure and rift tectonics across the Cauvery–Palar basin ...

    Indian Academy of Sciences (India)

    The Cauvery–Palar basin is a major peri-cratonic rift basin located along the Eastern Continental Margin of India (ECMI) that had formed during the rift-drift events associated with the breakup of eastern Gondwanaland (mainly India–Sri Lanka–East Antarctica). In the present study, we carry out an integrated analysis of the ...

  18. Kinematic and thermal evolution of the Moroccan rifted continental margin: Doukkala-High Atlas transect (United States)

    Gouiza, M.; Bertotti, G.; Hafid, M.; Cloetingh, S.


    The Atlantic passive margin of Morocco developed during Mesozoic times in association with the opening of the Central Atlantic and the Alpine Tethys. Extensional basins formed along the future continental margin and in the Atlas rift system. In Alpine times, this system was inverted to form the High and Middle Atlas fold-and-thrust belts. To provide a quantitative kinematic analysis of the evolution of the rifted margin, we present a crustal section crossing the Atlantic margin in the region of the Doukkala Basin, the Meseta and the Atlas system. We construct a post-rift upper crustal section compensating for Tertiary to present vertical movements and horizontal deformations, and we conduct numerical modeling to test quantitative relations between amounts and distribution of thinning and related vertical movements. Rifting along the transect began in the Late Triassic and ended with the appearance of oceanic crust at 175 Ma. Subsidence, possibly related to crustal thinning, continued in the Atlas rift in the Middle Jurassic. The numerical models confirm that the margin experienced a polyphase rifting history. The lithosphere along the transect preserved some strength throughout rifting with the Effective Elastic Thickness corresponding to an isotherm of 450°C. A mid-crustal level of necking of 15 km characterized the pre-rift lithosphere.

  19. Mapping rift domains within an inverted hyperextended rift system: The role of rift inheritance in controlling the present-day structure of the North Iberian margin (Bay of Biscay) (United States)

    Cadenas, Patricia; Fernández-Viejo, Gabriela; Álvarez-Pulgar, Javier; Tugend, Julie; Manatschal, Gianreto; Minshull, Tim


    This study presents a new rift domain map in the central and western North Iberian margin, in the southern Bay of Biscay. This margin was structured during polyphase Triassic to Lower Cretaceous rifting events which led to hyperextension and exhumation and the formation of oceanic crust during a short-lived seafloor spreading period. Extension was halted due to the Alpine convergence between the Iberian and the European plates which led to the formation of the Cantabrian-Pyrenean orogen during the Cenozoic. In the Bay of Biscay, while the northern Biscay margin was slightly inverted, the North Iberian margin, which is at present-day part of the western branch of the Alpine belt together with the Cantabrian Mountains, exhibits several degrees of compressional reactivation. This makes this area a natural laboratory to study the influence of rift inheritance into the inversion of a passive margin. Relying on the interpretation of geological and geophysical data and the integration of wide-angle results, we have mapped five rift domains, corresponding to the proximal, necking, hyperthinned, exhumed mantle, and oceanic domains. One of the main outcomes of this work is the identification of the Asturian Basin as part of a hyperthinned domain bounded to the north by the Le Danois basement high. We interpret Le Danois High as a rift-related crustal block inherited from the margin structure. Our results suggest that the inherited rift architecture controlled the subsequent compressional reactivation. The hyperextended domains within the abyssal plain focused most of the compression resulting in the development of an accretionary wedge and the underthrusting of part of these distal domains beneath the margin. The presence of the Le Danois continental block added complexity, conditioning the inversion undergone by the Asturian Basin. This residual block of less thinned continental crust acted as a local buttress hampering further compressional reactivation within the platform

  20. Late Jurassic – early Cretaceous inversion of rift structures, and linkage of petroleum system elements across post-rift unconformity, U.S. Chukchi Shelf, arctic Alaska (United States)

    Houseknecht, David W.; Connors, Christopher D.


    Basin evolution of the U.S. Chukchi shelf involved multiple phases, including Late Devonian–Permian rifting, Permian–Early Jurassic sagging, Late Jurassic–Neocomian inversion, and Cretaceous–Cenozoic foreland-basin development. The focus of ongoing exploration is a petroleum system that includes sag-phase source rocks; inversion-phase reservoir rocks; structure spanning the rift, sag, and inversion phases; and hydrocarbon generation during the foreland-basin phase.

  1. Oblique rift opening revealed by reoccurring magma injection in central Iceland

    KAUST Repository

    Ruch, Joel


    Extension deficit builds up over centuries at divergent plate boundaries and is recurrently removed during rifting events, accompanied by magma intrusions and transient metre-scale deformation. However, information on transient near-field deformation has rarely been captured, hindering progress in understanding rifting mechanisms and evolution. Here we show new evidence of oblique rift opening during a rifting event influenced by pre-existing fractures and two centuries of extension deficit accumulation. This event originated from the Bárðarbunga caldera and led to the largest basaltic eruption in Iceland in >200 years. The results show that the opening was initially accompanied by left-lateral shear that ceased with increasing opening. Our results imply that pre-existing fractures play a key role in controlling oblique rift opening at divergent plate boundaries.

  2. [Medical myths and notions in Ancient Greece]. (United States)

    Boulogne, J


    The article deals with the views on health and disease prevalent in Ancient Greece, the cradle of modern European medicine, focusing on the ever-present myths functioning in that realm despite attempts to rationally explain medical phenomena. On the basis of the works of Hippocrates and Galen, the author has distinguished five different epistemological attitudes towards those phenomena: the holistic, macrocosmological, monistic, anti-hypothetical and eclectic. The first was based on the idea of mechanical and logical causes. In medicine it is marked by determinism connected with climatic conditions. Hippocrates believed that health depended on the weather, in particular on the effects of winds, types of water and properties of soil. Myth emerged in this conception in the way matter - earth, water, air and fire - was conceived, particular in the properties ascribed to them: cold, humidity, aridity and warmth. The author charges that this conception was permeated with ethnocentrism and cites examples invoked by Hippocrates on the basis of his observations on the Scythians. The macrocosmological attitude involves subordinating medicine to cosmology. Man's body is a microcosm. The author cites the treatise 'On Diets', in which the greatest importance both in the universe and in processes taking place in the human body as ascribed to two factors - fire and water. Their combination was said to have played a crucial role in the typology of corporal and mental constitutions. Those features, together with the seasons of the year, mode of behaviour and food, constitute the four forces guiding vital processes. The author then presents the embryogenic conception contained in the cosmological treatise. It was based on such things as numerological speculations, hence - despite its rationalistic assumptions, consigns it to the mythic. The third attitude, the monistic approach, presents a treatise ascribed to Hippocrates 'On the Sacred Disease' and dealing with epilepsy. The

  3. Next-generation Geotectonic Data Analysis: Using pyGPlates to quantify Rift Obliquity during Supercontinent Dispersal (United States)

    Butterworth, Nathaniel; Brune, Sascha; Williams, Simon; Müller, Dietmar


    Fragmentation of a supercontinent by rifting is an integral part of plate tectonics, yet the dynamics that govern the success or failure of individual rift systems are still unclear. Recently, analytical and thermo-mechanical modelling has suggested that obliquely activated rifts are mechanically favoured over orthogonal rift systems. Hence, where two rift zones compete, the more oblique rift proceeds to break-up while the less oblique one stalls and becomes an aulacogen. This implies that the orientation and shape of individual rift systems affects the relative motion of Earth's continents during supercontinent break-up. We test this hypothesis using the latest global plate tectonic reconstructions for the past 200 million years. The analysis is performed using pyGPlates, a recently developed Python library that allows script-based access to the plate reconstruction software GPlates. We quantify rift obliquity, extension velocity and their temporal evolution for all small-scale rift segments that constituted a major rift system during the last 200 million years. Boundaries between continental and oceanic crust (COBs) mark the end of rifting and the beginning of sea floor spreading, which is why we use a global set of updated COBs in order to pinpoint continental break-up and as a proxy for the local trend of former rift systems. Analysing the entire length of all rift systems during the last 200 My, we find a mean obliquity of ~40° (measured as the angle between extension direction and local rift trend normal), with a standard deviation of 25°. More than 75% of all rift segments exceeded an obliquity of 20° highlighting the fact that oblique rifting is the rule, not the exception. More specifically, East and West Gondwana split along the East African coast with a mean obliquity of 45°. While rifting of the central and southern South Atlantic segment involved a low obliquity of 10°, the Equatorial Atlantic opened under a high angle of 60°. The separation of

  4. ALVIN investigation of an active propagating rift system, Galapagos 95.5° W (United States)

    Hey, R.N.; Sinton, J.M.; Kleinrock, M.C.; Yonover, R.N.; MacDonald, K.C.; Miller, S.P.; Searle, R.C.; Christie, D.M.; Atwater, T.M.; Sleep, Norman H.; Johnson, H. Paul; Neal, C.A.


    ALVIN investigations have defined the fine-scale structural and volcanic patterns produced by active rift and spreading center propagation and failure near 95.5° W on the Galapagos spreading center. Behind the initial lithospheric rifting, which is propagating nearly due west at about 50 km m.y.−1, a triangular block of preexisting lithosphere is being stretched and fractured, with some recent volcanism along curving fissures. A well-organized seafloor spreading center, an extensively faulted and fissured volcanic ridge, develops ~ 10 km (~ 200,000 years) behind the tectonic rift tip. Regional variations in the chemical compositions of the youngest lavas collected during this program contrast with those encompassing the entire 3 m.y. of propagation history for this region. A maximum in degree of magmatic differentiation occurs about 9 km behind the propagating rift tip, in a region of diffuse rifting. The propagating spreading center shows a gentle gradient in magmatic differentiation culminating at the SW-curving spreading center tip. Except for the doomed rift, which is in a constructional phase, tectonic activity also dominates over volcanic activity along the failing spreading system. In contrast to the propagating rift, failing rift lavas show a highly restricted range of compositions consistent with derivation from a declining upwelling zone accompanying rift failure. The lithosphere transferred from the Cocos to the Nazca plate by this propagator is extensively faulted and characterized by ubiquitous talus in one of the most tectonically disrupted areas of seafloor known. The pseudofault scarps, where the preexisting lithosphere was rifted apart, appear to include both normal and propagator lavas and are thus more lithologically complex than previously thought. Biological communities, probably vestimentiferan tubeworms, occur near the top of the outer pseudofault scarp, although no hydrothermal venting was observed.

  5. An Epidemiological Model of Rift Valley Fever with Spatial Dynamics

    Directory of Open Access Journals (Sweden)

    Tianchan Niu


    Full Text Available As a category A agent in the Center for Disease Control bioterrorism list, Rift Valley fever (RVF is considered a major threat to the United States (USA. Should the pathogen be intentionally or unintentionally introduced to the continental USA, there is tremendous potential for economic damages due to loss of livestock, trade restrictions, and subsequent food supply chain disruptions. We have incorporated the effects of space into a mathematical model of RVF in order to study the dynamics of the pathogen spread as affected by the movement of humans, livestock, and mosquitoes. The model accounts for the horizontal transmission of Rift Valley fever virus (RVFV between two mosquito and one livestock species, and mother-to-offspring transmission of virus in one of the mosquito species. Space effects are introduced by dividing geographic space into smaller patches and considering the patch-to-patch movement of species. For each patch, a system of ordinary differential equations models fractions of populations susceptible to, incubating, infectious with, or immune to RVFV. The main contribution of this work is a methodology for analyzing the likelihood of pathogen establishment should an introduction occur into an area devoid of RVF. Examples are provided for general and specific cases to illustrate the methodology.

  6. Rifting kinematics along the Arabian Margin, Red Sea (United States)

    Pierantoni, Pietro Paolo; Schettino, Antonio; Zanoni, Davide; Rasul, Najeeb


    The Red Sea represents a young basin floored by oceanic, transitional, or thinned continental crust that formed between Nubia and Arabia. According to most authors, rifting between Nubia and Arabia started in the late Oligocene ( 27 Ma) and it is still in progress in the northern part of the Red Sea at latitudes greater than 24°N. Conversely, the area south of 20.3°N displays a linear spreading ridge extending as south as 14.8°N, which formed in the early Pliocene (the first pulse of sea floor spreading occurred during chron C3n.2n, 4.62 Ma). A transition zone (between 24°N and 20.3°N, present-day coordinates) exists between the northern and the southern sectors, characterized by a segmented spreading center that started forming at 2.58 Ma (chron 2A, late Pliocene) in the southernmost area and propagated northwards. Some authors suggest that the present-day NE-SW spreading directions can be extended back to the early Miocene. However, we are going to show, on the basis of geological evidence from the Arabian margin, that at least two phases of rifting, characterized by distinct extension directions, are necessary to explain the observed structural pattern of deformation in a wide area extending from 28°N to 20°N. At present, there is no magnetic evidence for the existence of a linear spreading center in the northern Red Sea at latitudes higher than 24°N. In this area, the syn-rift pattern of deformation along the Arabian margin is only partly coherent with the present day NE-SW sea floor spreading directions and with the observed trend of fracture zones in the Red Sea. In fact, an older set of rift structures was found during 3 field trips performed along the northern and central Red Sea Arabian margin (2015-2016), suggesting the existence of an earlier rifting stage characterized by N-S trending strike-slip faults and E-W normal faults. The objective of the field trips was to investigate the hypothesis that an early phase of N-S extension and formation of

  7. The medical social centres in support of Roma in Greece

    DEFF Research Database (Denmark)

    Andrioti, Despena; Kotrotsou, Christina; Tsakatara, Vanta


    . Medical social centres operate in 33 Roma settlements all over the country. These centres provide vaccination, health promotion, disease prevention and health education services, as well as support in issuing documents and making appointments with health and social services. We recommend that the National......Roma people form the largest ethnic-minority group in Europe. They account for around 10 to 12 million people, and they face racism, discrimination and social exclusion in most countries. The Roma population of Greece currently numbers around 250 000 individuals. They have Greek nationality...... and enjoy the same rights, privileges and responsibilities as any other Greek citizens. Nevertheless, Roma in Greece face multiple inequalities and social exclusion in terms of housing, employment, education, and health and social services. In this report we present the outcome of a bestpractice initiative...

  8. Travelling to Greece for the summer 2011 Special Olympics. (United States)

    Pavli, Androula; Maltezou, Helena C


    The Special Olympics is a non-profit organization that was officially founded in 1968. Nowadays, the Special Olympics have evolved to a Global Movement that offers the opportunity to more than 3 million athletes with mental or physical disabilities from 185 countries to participate. The Special Olympics will take place in Greece from June 25 until July 4, 2011, where 7500 athletes from 185 countries will participate in 22 Olympic-type games. Mass gatherings such as Olympic Games represent a significant challenge for public health. This paper focuses on relevant health and safety issues for all travellers travelling to Greece for the summer 2011 Special Olympic Games. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Supporting sustainable electricity technologies in Greece using MCDM

    Energy Technology Data Exchange (ETDEWEB)

    Doukas, H.; Patlitzianas, K.D.; Psarras, J. [National Technical Univ., Athens (Greece). School of Electrical and Computer Engineering


    The penetration of sustainable technologies in electricity generation is low until now in Greece. However, the recent adoption of legislative rules towards the effective operation of liberalized markets, as well as the increased impact of climate change on the electricity sector towards the period 2008-2012, bring out these technologies as key means for establishing conditions of security, stability and environmental protection. The objective of this paper is to put on the map the sustainable technologies for electricity generation in Greece through the formulation of a collective interactive supportive framework, using an existing multi-criteria decision-making (MCDM) method to elaborate more realistic and transparent outcomes. The approach was implemented under the umbrella of the national Foresight Programme, to assist policy making for sustainable electricity generation technologies. [Author].

  10. From Asia Minor to Greece: History, Memory and Migration

    Directory of Open Access Journals (Sweden)

    Emine Yeşim Bedlek


    Full Text Available History and memory studies are among the most controversial topics of our era. While the official history is made up of state discourse, personal history reaches the reader through the memories of the individuals. The events that leave traces in memory are passed on to future generations by oral history studies. The pasts of individuals whose individual experiences are unpacked by the oral historians give us more detailed information about the traumas individuals. Yiannis Karatzoglou also documents his past in order to pass the traumas of migration due to the Lausanne Convention signed in 1923 between Greece and Turkey. This study examines the impact of the social, cultural and political decisions of Turkey and Greece on individuals through the life story of Yiannis in the light of history and memory.

  11. Historical overview of spinal deformities in ancient Greece

    Directory of Open Access Journals (Sweden)

    Kaspiris Angelos


    Full Text Available Abstract Little is known about the history of spinal deformities in ancient Greece. The present study summarizes what we know today for diagnosis and management of spinal deformities in ancient Greece, mainly from the medical treatises of Hippocrates and Galen. Hippocrates, through accurate observation and logical reasoning was led to accurate conclusions firstly for the structure of the spine and secondly for its diseases. He introduced the terms kyphosis and scoliosis and wrote in depth about diagnosis and treatment of kyphosis and less about scoliosis. The innovation of the board, the application of axial traction and even the principle of trans-abdominal correction for correction of spinal deformities have their origin in Hippocrates. Galen, who lived nearly five centuries later impressively described scoliosis, lordosis and kyphosis, provided aetiologic implications and used the same principles with Hippocrates for their management, while his studies influenced medical practice on spinal deformities for more than 1500 years.

  12. Online Communities: The Case of Immigrants in Greece (United States)

    Panaretou, Ioannis; Karousos, Nikos; Kostopoulos, Ioannis; Foteinou, Georgia-Barbara; Pavlidis, Giorgos

    Immigrants in Greece are an increasing population, very often threatened by poverty and social exclusion. At the same time Greek government has no formal policy concerning their assimilation in Greek society and this situation generates multiple problems in both immigrants and native population. In this work we suggest that new technology can alleviate these effects and we present specific tools and methodologies adopted by ANCE, in order to support online communities and specifically immigrant communities in Greece. This approach has the potential to support immigrant communities' in terms of the organization of personal data, communication, and provision of a working space for dedicated use. The Information System's operational features are also presented, along with other characteristics and state-of-the-art features in order to propose a general direction to the design of online communities' mechanisms.

  13. Long-term coupling and feedbacks between surface processes and tectonics during rifting (United States)

    Theunissen, Thomas; Huismans, Ritske S.


    Whereas significant efforts have been made to understand the relationship between mountain building and surfaces processes, limited research has been done on the relationship between surface processes and extensional tectonics. Here we present high-resolution 2-D coupled tectonic-surface processes modeling of extensional basin formation. The main aim is to find out how erosion and deposition affect the deformation in extensional systems. We test the combined effects of crustal rheology and varying surface process efficiency (erodibility, sea level) on structural style of rift and passive margin formation. The results show that both erosion of rift flank areas and basin deposition enhance localization of crustal deformation. Frictional-plastic extensional shear zones accumulate more deformation during a longer period of time, and loading of offshore basins can generate crustal ductile flow. In extreme cases sediment deposition delays lithospheric rupture. These mechanisms are enhanced when fluvial erosion, transport and deposition are efficient. We show that removal of mass from rift flanks and sedimentary loading in the basin area provide a first order feedback with tectonic deformation and control on rifted margin tectonic-morphology. However, surface processes do not change the first order structural style of rifting, which is largely controlled by crustal rheology. Rift escarpment morphology is function of paleo-topography and sea level. Variation of strain localization in natural rift systems correlates with the observed behavior and suggests similar feedbacks as demonstrated by the forward numerical models.

  14. Upper mantle seismic anisotropy in the intra-continental Kachchh rift zone, Gujarat, India (United States)

    Mandal, Prantik


    Shear wave splitting study of 411 SKS/SKKS phases covering backazimuth range of 13 ° to 305 ° recorded by 12 broadband stations in the Kachchh rift has led to estimates of fast axis orientations and splitting times for 118 good measurements. The average vector mean of fast axis orientation (86 ± 14 °) corresponds to the E-W axis of the Kachchh rift and the delay time (~ 1.6 s) is attributed to the ~ 184 km-thick upper mantle layer with 4% anisotropy. The anisotropic character observed for the Kachchh rift (KR) is comparable to other continental rifts and these are related to the high-temperature, lattice-preferred orientation fabric of olivine, inherited from the mantle flows. The source of the rift-axis parallel anisotropy is traced to the rift-parallel flows within the 76 ± 6 km-thick lithosphere. Additionally, the rift-parallel pockets of partial melts also induce anisotropy within the asthenosphere. Both these are inherited from the plume-lithosphere interaction during the Deccan/Reunion plume episode (~ 65 Ma).

  15. Rift-to-collision transition recorded by tectonothermal evolution of the northern Pyrenees (United States)

    Vacherat, Arnaud; Mouthereau, Frédéric; Pik, Raphaël.; Bellahsen, Nicolas; Gautheron, Cécile; Bernet, Matthias; Daudet, Maxime; Balansa, Jocelyn; Tibari, Bouchaib; Pinna Jamme, Rosella; Radal, Julien


    The impact of rift-related processes on tectonic and thermal evolution of collisional orogens is poorly documented. Here, we study the northern Pyrenees, a region that has preserved a geological record of the transition from rifting to collision. Using modeling of new low-temperature thermochronological data, including fission track and (U-Th)/He on apatite and zircon, we propose a temporal reconstruction of the inversion of the European rifted margin. Our data confirm that rifting and related cooling started in the Late Paleozoic-Triassic. Throughout the Jurassic and Early Cretaceous the European margin recorded slow heating during postrift subdsidence. Modeling of thermochronological data allows distinguishing subsidence and denudation controlled by south dipping normal faults in granitic massifs that reflect a second episode of crustal thinning at 130-110 Ma. Following onset of convergence at 83 Ma, shortening accumulated into the weak and hot Albian-Cenomanian rift basins floored by both hyperextended continental crust and exhumed subcontinental mantle. The lack of cooling during this initial stage of convergence is explained by the persistence of a high geothermal gradient. The onset of exhumation-related cooling is recognized in the whole Pyrenean region at 50-35 Ma. This timing reveals that the main phase of mountain building started when hyperextended rift basins closed and collision between proximal domains of the rifted margin occurred.

  16. Crustal thickness and Moho sharpness beneath the Midcontinent rift from receiver functions

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    Moikwathai Moidaki


    Full Text Available The Mesoproterozoic Midcontinent rift (MCR in the central US is an approximately 2000 km long, 100 km wide structure from Kansas to Michigan. During the 20-40 million years of rifting, a thick (up to 20 km layer of basaltic lava was deposited in the rift valleys. Quantifying the effects of the rifting and associated volcanic eruptions on the structure and composition of the crust and mantle beneath the MCR is important for the understanding of the evolution of continental lithosphere. In this study we measure the crustal thickness (H, and the sharpness of the Moho (R at about 24 portable and permanent stations in Iowa, Kansas, and South Dakota by stacking Pto- S converted waves (PmS and their multiples (PPmS and PSmS. Under the assumption that the crustal mean velocity in the study area is the same as the IASP91 earth model, we find a significantly thickened crust beneath the MCR of about 53 km. The crustal Vp/Vs ratios increases from about 1.80 off rift to as large as 1.95 within the rift, which corresponds to an increase of Poisson’s ratio from 0.28 to 0.32, suggesting a more mafic crust beneath the MCR. The R measurements are spatially variable and are relatively small in the vicinity of the MCR, indicating the disturbance of the original sharp Moho by the rifting and magmatic intrusion and volcanic eruption.

  17. Smoking cessation delivery by general practitioners in Crete, Greece. (United States)

    Girvalaki, Charis; Papadakis, Sophia; Vardavas, Constantine; Petridou, Eleni; Pipe, Andrew; Lionis, Christos


    Tobacco dependence treatment in clinical settings is of prime public health importance, especially in Greece, a country experiencing one of the highest rates of tobacco use in Europe. Our study aimed to examine the characteristics of tobacco users and document rates of tobacco treatment delivery in general practice settings in Crete, Greece. A cross-sectional sample of patients (n = 2, 261) was screened for current tobacco use in 25 general practices in Crete, Greece in 2015/16. Current tobacco users completed a survey following their clinic appointment that collected information on patient characteristics and rates at which the primary care physician delivered tobacco treatment using the evidence-based 4 A's (Ask, Advise, Assist, Arrange) model during their medical appointment and over the previous 12-month period. Multi-level modeling was used to analyze data and examine predictors of 4 A's delivery. Tobacco use prevalence was 38% among all patients screened. A total of 840 tobacco users completed the study survey [mean age 48.0 (SD 14.5) years, 57.6% male]. Approximately, half of the tobacco users reported their general practitioner 'asked' about their tobacco use and 'advised' them to quit smoking. Receiving 'assistance' with quitting (15.7%) and 'arranging' follow-up support (<3%) was infrequent. Patient education, presence of smoking-related illness, a positive screen for anxiety or depression and the type of medical appointment were associated with 4 A's delivery. Given the fundamental importance of addressing tobacco treatment, increasing the rates of 4 A's treatment in primary care settings in Greece is an important target for improving patient care.

  18. Involvement and Loyalty in Recreation Swimming in Greece: Investigating Relationships


    Evangelia Kontogianni; Charilaos Kouthouris; Achilleas Barlas; Vasileiοs Voutselas


    Present study tested the validity of involvement scale (Kyle et al., 2004), examined differences according demographic characteristics and investigated possible relationships between involvement and attitudinal loyalty in context of recreational swimming. Three hundred and forty nine participants (61.9% females) from a major swimming sport center in northern Greece, completed the three dimensional involvement model of Kyle’s et al (2004), and Armitage & Conner’s (1999) attitudinal loyalty’s i...

  19. The Bonny Method of Guided Imagery and Music in Greece


    Dag Körlin; Anna Böhmig


    In this interview Dag Körlin talks about the Guided Imagery and Music (GIM) training programme in Greece and his contribution to its development. He explains some of the main aspects of GIM as a receptive music therapy method; he points out the role of music in the therapeutic process and he talks about the importance of listening. Finally, he refers to the European Network of GIM.

  20. Allergic conjunctivitis and the most common allergens in Northern Greece


    Almaliotis, Diamantis; MICHAILOPOULOS, Pavlos; Gioulekas, Dimitrios; Giouleka, Paschalina; Papakosta, Despina; Siempis, Thomas; KARAMPATAKIS, Vasileios


    Background Ocular allergies affect a great part of the general population and often co exist with other allergic manifestations. In the present study, the prevalence of allergic conjunctivitis and the commonest allergens in allergic patients at an outpatient unit in Thessaloniki, Greece were evaluated. Methods This is a retrospective study regarding allergic patients who referred to an outpatient clinic between the 1st of January of 1996 and the 31st of December 2010. They completed relative ...

  1. Essays on the econometric analysis of electronic banking in Greece


    Giordani, Georgia


    Economic integration within and across countries, deregulation, advances in telecommunications and the growth of the Internet and other communication technologies have dramatically changed the nature and structure of financial services (Claessens et al., 2003). This study examines the adoption of electronic banking (e-banking) services offered by commercial banks in Greece. This is the first empirical investigation on the adoption of e-banking using a logit econometric model which contain...

  2. Greece and the refugee crisis: mental health context


    Christodoulou, George N.; Abou-Saleh, Mohammed T.


    The recent influx of refugees and immigrants to Greece has coincided with the ongoing and deteriorating financial crisis. This situation does not allow the Greek authorities to provide help to the desired extent. Yet, the church, local communities, medical societies and non-governmental organisations are offering good psychosocial support. In parallel with support for refugees it is important to provide support for the citizens of the host country. The rich countries of northern Europe should...

  3. The Bonny Method of Guided Imagery and Music in Greece

    Directory of Open Access Journals (Sweden)

    Dag Körlin


    Full Text Available In this interview Dag Körlin talks about the Guided Imagery and Music (GIM training programme in Greece and his contribution to its development. He explains some of the main aspects of GIM as a receptive music therapy method; he points out the role of music in the therapeutic process and he talks about the importance of listening. Finally, he refers to the European Network of GIM.

  4. Simple shear detachment fault system and marginal grabens in the southernmost Red Sea rift (United States)

    Tesfaye, Samson; Ghebreab, Woldai


    The NNW-SSE oriented Red Sea rift, which separates the African and Arabian plates, bifurcates southwards into two parallel branches, southeastern and southern, collectively referred to as the southernmost Red Sea rift. The southern branch forms the magmatically and seismo-tectonically active Afar rift, while the less active southeastern branch connects the Red Sea to the Gulf of Aden through the strait of Bab el Mandeb. The Afar rift is characterized by lateral heterogeneities in crustal thickness, and along-strike variation in extension. The Danakil horst, a counterclockwise rotating, narrow sliver of coherent continental relic, stands between the two rift branches. The western margin of the Afar rift is marked by a series of N-S aligned right-lateral-stepping and seismo-tectonically active marginal grabens. The tectonic configuration of the parallel rift branches, the alignment of the marginal grabens, and the Danakil horst are linked to the initial mode of stretching of the continental crust and its progressive deformation that led to the breakup of the once contiguous African-Arabian plates. We attribute the initial stretching of the continental crust to a simple shear ramp-flat detachment fault geometry where the marginal grabens mark the breakaway zone. The rift basins represent the ramps and the Danakil horst corresponds to the flat in the detachment fault system. As extension progressed, pure shear deformation dominated and overprinted the initial low-angle detachment fault system. Magmatic activity continues to play an integral part in extensional deformation in the southernmost Red Sea rift.

  5. Consequences of Rift Propagation for Spreading in Thick Oceanic Crust in Iceland (United States)

    Karson, J. A.


    Iceland has long been considered a natural laboratory for processes related to seafloor spreading, including propagating rifts, migrating transforms and rotating microplates. The thick, hot, weak crust and subaerial processes of Iceland result in variations on the themes developed along more typical parts of the global MOR system. Compared to most other parts of the MOR, Icelandic rift zones and transform faults are wider and more complex. Rift zones are defined by overlapping arrays of volcanic/tectonic spreading segments as much as 50 km wide. The most active rift zones propagate N and S away from the Iceland hot spot causing migration of transform faults. A trail of crust deformed by bookshelf faulting forms in their wakes. Dead or dying transform strands are truncated along pseudofaults that define propagation rates close to the full spreading rate of ~20 mm/yr. Pseudofaults are blurred by spreading across wide rift zones and laterally extensive subaerial lava flows. Propagation, with decreasing spreading toward the propagator tips causes rotation of crustal blocks on both sides of the active rift zones. The blocks deform internally by the widespread reactivation of spreading-related faults and zones of weakness along dike margins. The sense of slip on these rift-parallel strike-slip faults is inconsistent with transform-fault deformation. These various deformation features as well as subaxial subsidence that accommodate the thickening of the volcanic upper crustal units are probably confined to the brittle, seismogenic, upper 10 km of the crust. At least beneath the active rift zones, the upper crust is probably decoupled from hot, mechanically weak middle and lower gabbroic crust resulting in a broad plate boundary zone between the diverging lithosphere plates. Similar processes may occur at other types of propagating spreading centers and magmatic rifts.

  6. Exploring virtual reality technology and the Oculus Rift for the examination of digital pathology slides. (United States)

    Farahani, Navid; Post, Robert; Duboy, Jon; Ahmed, Ishtiaque; Kolowitz, Brian J; Krinchai, Teppituk; Monaco, Sara E; Fine, Jeffrey L; Hartman, Douglas J; Pantanowitz, Liron


    Digital slides obtained from whole slide imaging (WSI) platforms are typically viewed in two dimensions using desktop personal computer monitors or more recently on mobile devices. To the best of our knowledge, we are not aware of any studies viewing digital pathology slides in a virtual reality (VR) environment. VR technology enables users to be artificially immersed in and interact with a computer-simulated world. Oculus Rift is among the world's first consumer-targeted VR headsets, intended primarily for enhanced gaming. Our aim was to explore the use of the Oculus Rift for examining digital pathology slides in a VR environment. An Oculus Rift Development Kit 2 (DK2) was connected to a 64-bit computer running Virtual Desktop software. Glass slides from twenty randomly selected lymph node cases (ten with benign and ten malignant diagnoses) were digitized using a WSI scanner. Three pathologists reviewed these digital slides on a 27-inch 5K display and with the Oculus Rift after a 2-week washout period. Recorded endpoints included concordance of final diagnoses and time required to examine slides. The pathologists also rated their ease of navigation, image quality, and diagnostic confidence for both modalities. There was 90% diagnostic concordance when reviewing WSI using a 5K display and Oculus Rift. The time required to examine digital pathology slides on the 5K display averaged 39 s (range 10-120 s), compared to 62 s with the Oculus Rift (range 15-270 s). All pathologists confirmed that digital pathology slides were easily viewable in a VR environment. The ratings for image quality and diagnostic confidence were higher when using the 5K display. Using the Oculus Rift DK2 to view and navigate pathology whole slide images in a virtual environment is feasible for diagnostic purposes. However, image resolution using the Oculus Rift device was limited. Interactive VR technologies such as the Oculus Rift are novel tools that may be of use in digital pathology.

  7. Wastewater Recycling in Greece: The Case of Thessaloniki

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    Andreas Ilias


    Full Text Available In Greece, and particularly in many southeastern and island areas, there is severe pressure on water resources, further exacerbated by the high demand of water for tourism and irrigation in summertime. The integration of treated wastewater into water resources management is of paramount importance to meet future demands. Despite this need, only a few projects of effluent reuse have been implemented, most of them being pilot projects of crop or landscape irrigation. The most important projects which are currently in practice are those of Thessaloniki, Chalkida, Malia, Livadia, Amfisa, Kalikratia, and Chersonissos. In Thessaloniki, at the most important wastewater reuse site, the secondary effluent of the city’s Waste Water Treatment Plant (WWTP (165,000 m3/day is used for agricultural irrigation after mixing with freshwater at a 1:5 ratio. The main crops irrigated are rice, corn, alfalfa and cotton. A few other projects are under planning, such as that at Iraklion, Agios Nikolaos and several island regions. Finally, it should be mentioned that there are several cases of indirect reuse, especially in central Greece. However, the reuse potential in Greece is limited, since effluent from Athens’s WWTP, serving approximately half of the country’s population, is not economically feasible due to the location of the plant.

  8. Carbon Footprint Analysis of Municipalities – Evidence from Greece

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    K. Angelakoglou


    Full Text Available The economical crisis that hit Greece after 2009, significantly affected its energy consumption profile due to the increased price of domestic heating oil and gasoline. The specific study aims at the quantification of the carbon dioxide emissions in municipal level due to energy and fuel consumption. Three different municipalities in North Greece (Kavala, Alexandroupolis and Drama were assessed with the application of three different carbon footprint estimation approaches in each one of them, including two life cycle assessment methods. Results ranged from 511,799 to 571,000, 435,250 to 489,000 and 355,207 to 398,000 tons CO2 and tons CO2-eq. for Kavala, Alexandroupolis and Drama respectively. The analysis per energy type indicated the electrical energy consumption as the key factor affecting the results due to the relatively high CO2 emission coefficient of the electricity produced in Greece. The analysis per sector indicated that a percentage of nearly 75% of the total carbon footprint is assigned to the building sector whereas the private and commercial transport is accountable for the rest. Municipal activities (buildings, facilities, lighting and fleet contributed to a small percentage to the total carbon footprint (approx. 3-8%.

  9. Application of the Standardized Precipitation Index (SPI in Greece

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    Christos A. Karavitis


    Full Text Available The main premise of the current effort is that the use of a drought index, such as Standardized Precipitation Index (SPI, may lead to a more appropriate understanding of drought duration, magnitude and spatial extent in semi-arid areas like Greece. The importance of the Index may be marked in its simplicity and its ability to identify the beginning and end of a drought event. Thus, it may point towards drought contingency planning and through it to drought alert mechanisms. In this context, Greece, as it very often faces the hazardous impacts of droughts, presents an almost ideal case for the SPI application. The present approach examines the SPI drought index application for all of Greece and it is evaluated accordingly by historical precipitation data. Different time series of data from 46 precipitation stations, covering the period 1947–2004, and for time scales of 1, 3, 6, 12 and 24 months, were used. The computation of the index was achieved by the appropriate usage of a pertinent software tool. Then, spatial representation of the SPI values was carried out with geo-statistical methods using the SURFER 9 software package. The results underline the potential that the SPI usage exhibits in a drought alert and forecasting effort as part of a drought contingency planning posture.


    Kani, Chara; Kourafalos, Vasilios; Litsa, Panagiota


    The aim of this study was to describe the current regulatory environment in Greece to evaluate the potential introduction of health technology assessment (HTA) for medicinal products for human use. Data sources consist of national legislation on pricing and reimbursement of health technologies to identify the potential need of establishing HTA and its relevant structure. The pricing procedure regarding medicinal products for human use is based on an external reference pricing mechanism which considers the average of the three lowest Euorpean Union prices. Currently, a formal HTA procedure has not been applied in Greece, and the only prerequisite used for the reimbursement of medicinal products for human use is their inclusion in the Positive Reimbursement List. To restrict pharmaceutical expenditure, a variety of measures-such as clawback mechanisms, rebates, monthly budget caps per physician, generics penetration targeting-have been imposed, aiming mainly to regulate the price level rather than control the introduction of medicinal products for human use in the Greek pharmaceutical market. Greece has the opportunity to rapidly build capacity, implement, and take advantage of the application of HTA mechanisms by clearly defining the goals, scope, systems, context, stakeholders, and methods that will be involved in the local HTA processes, taking into account the country's established e-prescription system and the recently adapted legislative framework.

  11. Political determinants of social expenditures in Greece: an empirical analysis

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    Ebru Canikalp


    Full Text Available A view prominently expounded is that the interaction between the composition and the volume of public expenditures is directly affected by political, institutional, psephological and ideological indicators. A crucial component of public expenditures, social expenditures play an important role in the economy as they directly and indirectly affect the distribution of income and wealth. Social expenditures aim at reallocating income and wealth unequal distribution. These expenditures comprise cash benefits, direct in-kind provision of goods and services, and tax breaks with social purposes.The aim of this study is to determine the relationship between political structure, i.e. government fragmentation, ideological composition, elections and so on, and the social expenditures in Greece. Employing data from the Comparative Political Dataset (CPDS and the OECD Social Expenditure Database (SOCX, a time series analysis was conducted for Greece for the 1980-2014 period. The findings of the study indicate that voter turnout, spending on the elderly population and the number of government changes have positive and statistically significant effects on social expenditures in Greece while debt stock and cabinet composition have negative effects.

  12. Rural primary care in Greece: working under limited resources. (United States)

    Oikonomidou, Eirini; Anastasiou, Foteini; Dervas, Dimitris; Patri, Fani; Karaklidis, Dionisis; Moustakas, Panagiotis; Andreadou, Niki; Mantzanas, Enagellos; Merkouris, Bodossakis


    Establishing sufficient primary health-care services in rural areas is of high interest in developing health systems. The objective of the present study was to describe the state of rural health services, in terms of personnel and equipment, in rural primary care settings in Greece. A questionnaire was sent to all Greek rural settings (RS) (practices) twice during 2007. The questionnaire included questions about the number of doctors in the practice, their specialty, presence of a nurse, population served and average distance from the regional Health Center and hospital. It also included questions about the average number of consultations per day, home visits, maintenance of medical records and medical equipment. Rural primary care settings in Greece. Doctors serving primary care needs during the second half of 2007. s) None. s) Data concerning staffing, function and available equipment of the RS have been collected. Five hundred eighty-two (40.9%) of the rural practitioners replied. Twenty-nine percent of the participants were general practitioners (GPs). Doctors reported average population of responsibility of 2263 citizens and a regular average of 26 consultations per day. A nurse was present in 174 RS (29.5%). Medical records of any form were kept in only 36% of the RS. GPs were more prone to maintain patients files compared with non-specialized doctors. Essential equipment proved to be limited in the majority of the RS. Rural practices in Greece report shortages of medical staff (GPs), nursing staff and equipment.

  13. Littoral sedimentation of rift lakes: an illustrated overview from the modern to Pliocene Lake Turkana (East African Rift System, Kenya) (United States)

    Schuster, Mathieu; Nutz, Alexis


    Existing depositional models for rift lakes can be summarized as clastics transported by axial and lateral rivers, then distributed by fan-deltas and/or deltas into a standing water body which is dominated by settling of fine particles, and experiencing occasional coarser underflows. Even if known from paleolakes and modern lakes, reworking of clastics by alongshore drift, waves and storms are rarely considered in depositional models. However, if we consider the lake Turkana Basin (East African Rift System, Kenya) it is obvious that this vision is incomplete. Three representative time slices are considered here: the modern Lake Turkana, the Megalake Turkana which developed thanks to the African Humid Period (Holocene), and the Plio-Pleistocene highstand episodes of paleolake Turkana (Nachukui, Shungura and Koobi Fora Formations, Omo Group). First, remarkable clastic morphosedimentary structures such as beach ridges, spits, washover fans, lagoons, or wave-dominated deltas are very well developed along the shoreline of modern lake Turkana, suggesting strong hydrodynamics responsible for a major reworking of the fluvial-derived clastics all along the littoral zone (longshore and cross-shore transport) of the lake. Similarly, past hydrodynamics are recorded from prominent raised beach ridges and spits, well-preserved all around the lake, above its present water-level (~360 m asl) and up to ~455 m. These large-scale clastic morphosedimentary structures also record the maximum extent of Megalake Turkana during the African Humid Period, as well as its subsequent regression forced by the end of the Holocene climatic optimum. Several hundreds of meters of fluvial-deltaic-lacustrine deposits spanning the Pliocene-Pleistocene are exposed in the Turkana basin thanks to tectonic faulting. These deposits are world famous for their paleontological and archeological content that documents the very early story of Mankind. They also preserve several paleolake highstand episodes with

  14. A heuristic expert system for forest fire guidance in Greece. (United States)

    Iliadis, Lazaros S; Papastavrou, Anastasios K; Lefakis, Panagiotis D


    Forests and forestlands are common inheritance for all Greeks and a piece of the national wealth that must be handed over to the next generations in the best possible condition. After 1974, Greece faces a severe forest fire problem and forest fire forecasting is the process that will enable the Greek ministry of Agriculture to reduce the destruction. This paper describes the basic design principles of an Expert System that performs forest fire forecasting (for the following fire season) and classification of the prefectures of Greece into forest fire risk zones. The Expert system handles uncertainty and uses heuristics in order to produce scenarios based on the presence or absence of various qualitative factors. The initial research focused on the construction of a mathematical model which attempted to describe the annual number of forest fires and burnt area in Greece based on historical data. However this has proven to be impossible using regression analysis and time series. A closer analysis of the fire data revealed that two qualitative factors dramatically affect the number of forest fires and the hectares of burnt areas annually. The first is political stability and national elections and the other is drought cycles. Heuristics were constructed that use political stability and drought cycles, to provide forest fire guidance. Fuzzy logic was applied to produce a fuzzy expected interval for each prefecture of Greece. A fuzzy expected interval is a narrow interval of values that best describes the situation in the country or a part of the country for a certain time period. A successful classification of the prefectures of Greece in forest fire risk zones was done by the system, by comparing the fuzzy expected intervals to each other. The system was tested for the years 1994 and 1995. The testing has clearly shown that the system can predict accurately, the number of forest fires for each prefecture for the following year. The average accuracy was as high as 85

  15. His Excellency Mr Alexandros Alexandris Ambassador, Permanent Representative of Greece to the United Nations Office at Geneva and other international organizations in Switzerland and Officials from the East Macedonia and Thrace Region Greece

    CERN Multimedia

    Jean-Claude Gadmer


    His Excellency Mr Alexandros Alexandris Ambassador, Permanent Representative of Greece to the United Nations Office at Geneva and other international organizations in Switzerland and Officials from the East Macedonia and Thrace Region Greece

  16. Triassic rift-related sedimentary basins in northern Chile (24° 29°S) (United States)

    Suarez, M.; Bell, C. M.


    Triassic rocks in northern Chile (latitude 24°-29°S) include marine and continental rift-related sedimentary deposits, associated with basaltic, andesitic, and silicic volcanic rocks. Five main successions include the deposits of two marine basins (Profeta and San Félix) separated by three continental basins (Cifuncho, La Ternera, and La Coipa). The marine strata include turbidites and debris flow deposits interpreted as coarse-grained fan-delta sediments. The continental sediments include lacustrine fan delta, open lake, braided river, alluvial fan, and sabkha deposits. The widespread fan-delta systems (both marine and lacustrine), together with abrupt lateral and vertical facies discontinuities and large-scale depositional cycles, are indicative of rift-controlled sedimentation. The associated magmatic activity indicates that this rifting was the product of subduction-related extension or strike-slip movement on the active plate margin. Triassic rifting was followed in Late Triassic to Early Jurassic times by widespread thermotectonic subsidence.

  17. Data-driven modeling to assess receptivity for Rift Valley Fever virus

    National Research Council Canada - National Science Library

    Barker, Christopher M; Niu, Tianchan; Reisen, William K; Hartley, David M


    Rift Valley Fever virus (RVFV) is an enzootic virus that causes extensive morbidity and mortality in domestic ruminants in Africa, and it has shown the potential to invade other areas such as the Arabian Peninsula...

  18. A hierarchical network approach for modeling Rift Valley fever epidemics with applications in North America

    National Research Council Canada - National Science Library

    Xue, Ling; Cohnstaedt, Lee W; Scott, H Morgan; Scoglio, Caterina


    .... In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors...

  19. Data-Driven Modeling to Assess Receptivity for Rift Valley Fever Virus: e2515

    National Research Council Canada - National Science Library

    Christopher M Barker; Tianchan Niu; William K Reisen; David M Hartley


      Rift Valley Fever virus (RVFV) is an enzootic virus that causes extensive morbidity and mortality in domestic ruminants in Africa, and it has shown the potential to invade other areas such as the Arabian Peninsula...

  20. Inflation rates, rifts, and bands in a pāhoehoe sheet flow (United States)

    Hoblitt, Richard P.; Orr, Tim R.; Heliker, Christina; Denlinger, Roger P.; Hon, Ken; Cervelli, Peter F.


    The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping Inflation and rift-band formation is probably cyclic, because the pattern we observed suggests episodic or crude cyclic behavior. Furthermore, some inflation rifts contain numerous bands whose spacing and general appearances are remarkably similar. We propose a conceptual model wherein the inferred cyclicity is due to the competition between the fluid pressure in the flow's liquid core and the tensile strength of the viscoelastic layer where it is weakest—in inflation rifts. The viscoelastic layer consists of lava that has cooled to temperatures between 800 and 1070 °C. This layer is the key parameter in our model because, in its absence, rift banding and stepwise changes in the flow height would not occur.

  1. Micrometre-scale deformation observations reveal fundamental controls on geological rifting. (United States)

    Thun, Johannes; Lokmer, Ivan; Bean, Christopher J; Eibl, Eva P S; Bergsson, Bergur H; Braiden, Aoife


    Many of the world's largest volcanic eruptions are associated with geological rifting where major fractures open at the Earth's surface, yet fundamental controls on the near-surface response to the rifting process are lacking. New high resolution observations gleaned from seismometer data during the 2014 Bárðarbunga basaltic dyke intrusion in Iceland allow us unprecedented access to the associated graben formation process on both sub-second and micrometre scales. We find that what appears as quasi steady-state near-surface rifting on lower resolution GPS observation comprises discrete staccato-like deformation steps as the upper crust unzips through repetitive low magnitude (MW earthquakes, demonstrating that the uppermost crust in the rift zone is exceptionally weak.

  2. Origin of three-armed rifts in volcanic islands: the case of El Hierro (Canary Islands) (United States)

    Galindo Jiménez, Inés; Becerril Carretero, Laura; Martí Molist, Joan; Gudmundsson, Agust


    Rifts zones in volcanic oceanic islands are common structures that have been explained through several theories/models. However, despite all these models it is as yet unclear whether it is the intense intrusive activity or the sector collapses that actually control the structural evolution and geometry of oceanic-island rift zones. Here we provide a new hypothesis to explain the origin and characteristics of the feeding system of oceanic-island rift zones based on the analysis of more than 1700 surface, subsurface (water galleries), and submarine structural data from El Hierro (Canary Islands). El Hierro's geological structure is primarily controlled by a three-armed rift-zone, the arms striking NE, WSW and S. Between the rift axes there are three valleys formed during huge landslides: El Golfo, El Julan, and Las Playas. Our results show: (1) a predominant NE-SW strike of structural elements, which coincides with the main regional trend of the Canary Archipelago as a whole; (2) a clear radial strike distribution of structural elements for the whole volcanic edifice (including submarine flanks) with respect to the centre of the island; (3) that the rift zones are mainly subaerial structures and do not propagate through the submarine edifice; (4) that it is only in the NE rift that structures have a general strike similar to that of the rift as a whole, and; (5) that in the W and S rifts there is not clear main direction, showing the structural elements in the W rift a fan distribution coinciding with the general radial pattern in the island as a whole. Based on these data, we suggest that the radial-striking structures reflect comparatively uniform stress fields that operated during the constructive episodes, mainly conditioned by the combination of overburden pressure, gravitational spreading, and magma-induced stresses. By contrast, in the shallower parts of the edifice, that is, the NE-SW, N-S and WNW-ESE-striking structures, reflect local stress fields related

  3. The magmatic budget of Atlantic type rifted margins: is it related to inheritance? (United States)

    Manatschal, Gianreto; Tugend, Julia; Picazo, Suzanne; Müntener, Othmar


    In the past, Atlantic type rifted margins were either classified as volcanic or non-volcanic. An increasing number of high quality reflection and refraction seismic surveys and drill hole data show a divergent style of margin architecture and an evolution in which the quantity and distribution of syn-rift magmatism is variable, independently of the amount of extension. Overgeneralized classifications and models assuming simple relations between magmatic and extensional systems are thus inappropriate to describe the formation of rifted margins. More recent studies show that the magmatic evolution of rifted margins is complex and cannot be characterized based on the volume of observed magma alone. On the one hand, so-called "non-volcanic" margins are not necessarily amagmatic, as shown by the results of ODP drilling along the Iberia-Newfoundland rifted margins. On the other hand, magma-rich margins, such as the Norwegian, NW Australian or the Namibia rifted margins show evidence for hyper-extension prior to breakup. These observations suggest that the magmatic budget does not only depend on extension rates but also on the composition and temperature of the decompressing mantle. Moreover, the fact that the magmatic budget may change very abruptly along strike and across the margin is difficult to reconcile with the occurrence of plumes or other deep-seated large-scale mantle phenomena only. These overall observations result in questions on how magmatic and tectonic processes are interacting during rifting and lithospheric breakup and on how far inheritance may control the magmatic budget during rifting. In our presentation we will review results from the South and North Atlantic and the Alpine Tethys domain and will discuss the structural and magmatic evolution of so-called magma-rich and magma-poor rifted margins. In particular, we will try to define when, where and how much magma forms during rifting and lithospheric breakup. The key questions that we aim to address

  4. Breaking the paradigm at magma-poor and magma-rich rifted margins (United States)

    Tugend, Julie; Manatschal, Gianreto; Gillard, Morgane; Nirrengarten, Michael; Epin, Marie-Eva; Sauter, Daniel; Autin, Julia; Harkin, Caroline; Kusznir, Nick


    Rifted margins used to be classified into volcanic or non-volcanic passive margins. Because magmatism is evidenced even in so-called 'non-volcanic' settings, this terminology was later adjusted to magma-poor and magma-rich rifted margins. This classification represents a simplification into end-member magmatic types depending on the magmatic budget related to rifting and/or breakup processes. New observations derived from higher quality geophysical data sets and drill-hole data revealed the great diversity of rifted margin architecture and highly variable distribution of rift-related and/or breakup related magmatism. Recent studies suggest that rifted margins have a more complex tectono-magmatic evolution than previously assumed and cannot be characterized based on the observed volume of magma alone. In this study, we present seismic observations from 2D high resolution long-offset deep reflection seismic profiles across the East-Indian and South-Atlantic rifted margins. We aim to compare structural similarities between rifted margins with different magmatic budgets. We apply a systematic seismic interpretation approach to describe and characterize the first-order architecture and magmatic budget of our case examples. The identification of magmatic additions based on seismic observations only is indeed not unequivocal, in spite of the high-resolution dataset. Interpretations are related to large uncertainties in particular at ocean-continent transitions (i.e. outer highs) where most of the magmatism seems to be located. For each line, we present three different interpretations based on offshore and/or onshore field analogues. These interpretations illustrate scenarios for the nature of the outer highs that we believe are geologically meaningful and reasonable, and imply different magmatic budgets at breakup. Based on these interpretations we discuss different mechanisms for lithospheric breakup involving either a gradual or more instantaneous process independently

  5. Teleseismic Investigations of the Malawi and Luangwa Rift Zones: Ongoing Observations From the SAFARI Experiment (United States)

    Reed, C. A.; Gao, S. S.; Liu, K. H.; Yu, Y.; Chindandali, P. R. N.; Massinque, B.; Mdala, H. S.; Mutamina, D. M.


    In order to evaluate the influence of crustal and mantle heterogeneities upon the initiation of the Malawi rift zone (MRZ) and reactivation of the Zambian Luangwa rift zone (LRZ) subject to Cenozoic plate boundary stress fields and mantle buoyancy forces, we installed and operated 33 Seismic Arrays For African Rift Initiation (SAFARI) three-component broadband seismic stations in Malawi, Mozambique, and Zambia from 2012 to 2014. During the twenty-four month acquisition period, nearly 6200 radial receiver functions (RFs) were recorded. Stations situated within the MRZ, either along the coastal plains or within the Shire Graben toward the south, report an average crustal thickness of 42 km relative to approximately 46 km observed at stations located along the rift flanks. This implies the juvenile MRZ is characterized by a stretching factor not exceeding 1.1. Meanwhile, P-to-S velocity ratios within the MRZ increase from 1.71 to 1.82 in southernmost Malawi, indicating a substantial modification of the crust during Recent rifting. Time-series stacking of approximately 5500 RFs recorded by the SAFARI and 44 neighboring network stations reveals an apparent uplift of 10 to 15 km along both the 410- and 660-km mantle transition zone (MTZ) discontinuities beneath the MRZ and LRZ which, coupled with an apparently normal 250-km MTZ thickness, implies a first-order high-velocity contribution from thickened lithosphere. Preliminary manual checking of SAFARI shear-wave splitting (SWS) measurements provides roughly 650 high-quality XKS phases following a component re-orientation to correct station misalignments. Regional azimuthal variations in SWS fast orientations are observed, from rift-parallel in the vicinity of the LRZ to rift-oblique in the MRZ. A major 60° rotation in the fast orientation occurs at approximately 31°E, possibly resulting from the modulation of mantle flow around a relatively thick lithospheric keel situated between the two rift zones.

  6. Imaging the midcontinent rift beneath Lake Superior using large aperture seismic data (United States)

    Trehu, Anne M.; Morel-a-l'Huissier, Patrick; Meyer, R.; Hajnal, Z.; Karl, J.; Mereu, R. F.; Sexton, J.; Shay, J.; Chan, W. K.; Epili, D.; Jefferson, T.; Shih, X. R.; Wendling, S.; Milkereit, B.; Green, A.; Hutchinson, Deborah R.


    We present a detailed velocity model across the 1.1 billion year old Midcontinent Rift System (MRS) in central Lake Superior. The model was derived primarily from onshore-offshore large-aperture seismic and gravity data. High velocities obtained within a highly reflective half-graben that was imaged on coincident seismic reflection data demonstrate the dominantly mafic composition of the graben fill and constrain its total thickness to be at least 30km. Strong wide-angle reflections are observed from the lower crust and Moho, indicating that the crust is thickest (55–60km) beneath the axis of the graben. The total crustal thickness decreases rapidly to about 40 km beneath the south shore of the lake and decreases more gradually to the north. Above the Moho is a high-velocity lower crust interpreted to result from syn-rift basaltic intrusion into and/or underplating beneath the Archean lower crust. The lower crust is thickest beneath the axis of the main rift half-graben. A second region of thick lower crust is found approximately 100km north of the axis of the rift beneath a smaller half graben that is interpreted to reflect an earlier stage of rifting. The crustal model presented here resembles recent models of some passive continental margins and is in marked contrast to many models of both active and extinct Phanerozoic continental rift zones. It demonstrates that the Moho is a dynamic feature, since the pre-rift Moho is probably within or above the high-velocity lower crust, whereas the post-rift Moho is defined as the base of this layer. In the absence of major tectonic activity, however, the Moho is very stable, since the large, abrupt variations in crustal thickness beneath the MRS have been preserved for at least a billion years.

  7. Basement structure and its influence on the structural configuration of the northern North Sea rift (United States)

    Fazlikhani, Hamed; Fossen, Haakon; Gawthorpe, Robert L.; Faleide, Jan Inge; Bell, Rebecca E.


    The northern North Sea rift basin developed on a heterogeneous crust comprising structures inherited from the Caledonian orogeny and Devonian postorogenic extension. Integrating two-dimensional regional seismic reflection data and information from basement wells, we investigate the prerift structural configuration in the northern North Sea rift. Three seismic facies have been defined below the base rift surface: (1) relatively low-amplitude and low-frequency reflections, interpreted as pre-Caledonian metasediments, Caledonian nappes, and/or Devonian clastic sediments; (2) packages of high-amplitude dipping reflections (>500 ms thick), interpreted as basement shear zones; and (3) medium-amplitude and high-frequency reflections interpreted as less sheared crystalline basement of Proterozoic and Paleozoic (Caledonian) origin. Some zones of Seismic Facies 2 can be linked to onshore Devonian shear zones, whereas others are restricted to the offshore rift area. Interpreted offshore shear zones dip S, ESE, and WNW in contrast to W to NW dipping shear zones onshore West Norway. Our results indicate that Devonian strain and ductile deformation was distributed throughout the Caledonian orogenic belt from central South Norway to the Shetland Platform. Most of the Devonian basins related to this extension are, however, removed by erosion during subsequent exhumation. Basement shear zones reactivated during the rifting and locally control the location and geometry of rift depocenters, e.g., in the Stord and East Shetland basins. Prerift structures with present-day dips >15° were reactivated, although some of the basement shear zones are displaced by rift faults regardless of their orientation relative to rift extension direction.

  8. Seismic hazard assessment of the Kivu rift segment based on a new seismotectonic zonation model (western branch, East African Rift system) (United States)

    Delvaux, Damien; Mulumba, Jean-Luc; Sebagenzi, Mwene Ntabwoba Stanislas; Bondo, Silvanos Fiama; Kervyn, François; Havenith, Hans-Balder


    In the frame of the Belgian GeoRisCA multi-risk assessment project focusing on the Kivu and northern Tanganyika rift region in Central Africa, a new probabilistic seismic hazard assessment has been performed for the Kivu rift segment in the central part of the western branch of the East African rift system. As the geological and tectonic setting of this region is incompletely known, especially the part lying in the Democratic Republic of the Congo, we compiled homogeneous cross-border tectonic and neotectonic maps. The seismic risk assessment is based on a new earthquake catalogue based on the ISC reviewed earthquake catalogue and supplemented by other local catalogues and new macroseismic epicenter data spanning 126 years, with 1068 events. The magnitudes have been homogenized to Mw and aftershocks removed. The final catalogue used for the seismic hazard assessment spans 60 years, from 1955 to 2015, with 359 events and a magnitude of completeness of 4.4. The seismotectonic zonation into 7 seismic source areas was done on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of thermal springs and earthquake epicenters. The Gutenberg-Richter seismic hazard parameters were determined by the least square linear fit and the maximum likelihood method. Seismic hazard maps have been computed using existing attenuation laws with the Crisis 2012 software. We obtained higher PGA values (475 years return period) for the Kivu rift region than the previous estimates. They also vary laterally in function of the tectonic setting, with the lowest value in the volcanically active Virunga - Rutshuru zone, highest in the currently non-volcanic parts of Lake Kivu, Rusizi valley and North Tanganyika rift zone, and intermediate in the regions flanking the axial rift zone.

  9. The evolution of the western rift area of the Fimbul Ice Shelf, Antarctica

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    A. Humbert


    Full Text Available This paper studies the evolution of a zone in the Fimbul Ice Shelf that is characterised by large crevasses and rifts west of Jutulstraumen, an outlet glacier flowing into Fimbulisen. High-resolution radar imagery and radio echo sounding data were used to study the surface and internal structure of this rift area and to define zones of similar characteristics. The western rift area is dominated by two factors: a small ice rumple that leads to basal crevasses and disturbs the homogeneity of the ice, and a zone with fibre-like blocks. Downstream of the rumple we found down-welling of internal layers and local thinning, which we explain as a result of basal crevasses due to the basal drag at the ice rumple. North of Ahlmannryggen the ice loses its lateral constraint and forms individual blocks, which are deformed like fibres under shear, where the ice stream merges with slower moving ice masses of the western side. There, the ice loses its integrity, which initiates the western rift system. The velocity difference between the slow moving western part and the fast moving extension of Jutulstraumen produces shear stress that causes the rifts to form tails and expand them to the major rifts of up to 30 km length.

  10. Quantification and restoration of extensional deformation along the Western Iberia and Newfoundland rifted margins (United States)

    Sutra, Emilie; Manatschal, Gianreto; Mohn, Geoffroy; Unternehr, Patrick


    Many recent papers describe the structure of the Iberia and Newfoundland rifted margins; however, none of them propose kinematic restorations of the complete rift system to quantify the amount of extension necessary to exhume mantle and initiate seafloor spreading. In our study, we use two pairs of cross sections considered as conjugate lines: one across the Galicia Bank-Flemish Cap and the other across the Southern Iberia Abyssal Plain-Flemish Pass. Both transects have been imaged by reflection- and refraction-seismic methods and have been drilled during Ocean Drilling Program Legs 103, 149, 173, and 210. Drilling penetrated parts of the rift stratigraphy and the underlying basement. The cross sections can therefore be considered as the best-documented conjugate transects across present-day hyperextended, magma-poor rifted margins. The aim of this paper is threefold: (1) provide a detailed description of the crustal architecture of the two conjugate sections, (2) define the extensional structures and their ages, and (3) quantify the amount of strain and strain rate accommodated along these lines. This paper proposes a quantitative description of extension along the Iberia-Newfoundland rift system and discusses the limitations and problems in quantifying extensional deformation along hyperextended rifted margins.

  11. Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities. (United States)

    Foerster, Rebecca M; Poth, Christian H; Behler, Christian; Botsch, Mario; Schneider, Werner X


    Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen's visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions.

  12. The urban roots of anti-neoliberal social movements: the case of Athens, Greece

    NARCIS (Netherlands)

    Arampatzi, A.; Nicholls, W.J.


    The recent rounds of anti-neoliberal mobilizations in Europe have shown to be rooted in cities. Whereas Madrid has become a central hub in Spain’s social movement, Athens has assumed a central and centralizing role in Greece. Through a case study on Athens, Greece, this paper aims to show how cities

  13. Working with Students with Special Educational Needs in Greece: Teachers' Stressors and Coping Strategies (United States)

    Antoniou, Alexander-Stamatios; Polychroni, Fotini; Kotroni, Christina


    Few studies explore the specific sources of stress, and the coping strategies applied by teachers of children with special educational needs, particularly in small countries such as Greece. The present study investigated the specific work-related stressors affecting special educational needs teachers in Greece and the coping strategies applied by…

  14. The Effect of Education on Economic Growth in Greece over the 1960-2000 Period (United States)

    Tsamadias, Constantinos; Prontzas, Panagiotis


    This paper examines the impact of education on economic growth in Greece over the period 1960-2000 by applying the model introduced by Mankiw, Romer, and Weil. The findings of the empirical analysis reveal that education had a positive and statistically significant effect on economic growth in Greece over the period 1960-2000. The econometric…

  15. Engineering Education and Industry in Greece: Towards a Long Overdue Convergence. (United States)

    Polydorides, Nicos D.


    Discusses (1) the development of engineering education in Greece; (2) industrial development in Greece; (3) relations between engineering education and industry (indicating that they are best characterized by mutual suspicion); and (4) recent developments and future trends in these relationships. (JN)

  16. Geometra papilionaria (Linnaeus, 1758 (Lepidoptera: Geometridae: a new species for the fauna of Greece

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    Tóth, Balázs


    Full Text Available The first record of Geometra papilionaria L. from Greece is provided, extending the known area of the species in the Balkan Peninsula and raising the Geometrinae fauna of Greece to 18 species. A brief characterisation of the collecting site is also given. The voucher specimen is deposited in the Hungarian Natural History Museum, Budapest. With two figures.

  17. Illegal immigration and local labour markets: the case of northern Greece. (United States)

    Lianos, T P; Sarris, A H; Katseli, L T


    "The purpose of the present study is to enhance knowledge on the impact of illegal immigrants in Greece from both Eastern European and other developing countries. Our analysis is based on direct survey information from the four regions in Greece which employ considerable numbers of illegal aliens." (SUMMARY IN FRE AND SPA) excerpt

  18. Emerging Trichinella britovi infections in free ranging pigs of Greece. (United States)

    Boutsini, S; Papatsiros, V G; Stougiou, D; Marucci, G; Liandris, E; Athanasiou, L V; Papadoudis, A; Karagiozopoulos, E; Bisias, A; Pozio, E


    Trichinella infections in humans and pigs have been documented in Greece since 1945 and a high prevalence of infection in pigs occurred in the 1950s. Up to 1984 only sporadic infections in humans were documented, and this zoonosis was not considered as a public health problem until 2009 when a human outbreak caused by the consumption of pork from an organic pig farm occurred. In the present study, we describe the re-emergence of Trichinella spp. infections in free-ranging pigs from organic farms of 3 counties (Dramas, Evros and Kavala) in Northern-Eastern Greece during the period 2009-2012. Totally 37 out of 12,717 (0.29%) free-ranging pigs which were tested during the period in question, were positive for Trichinella spp. larvae. The etiological agent was identified as Trichinella britovi. The average larval burden was 13.7 in the masseter, 6.2 in the foreleg muscles and 7.5 in the diaphragm. The 37 positive animals originated from seven free range pig farms. The practice of organic pig production systems in Greece has grown in popularity over the last years due to the increasing interest of consumers for products considered as traditional. However, this type of pig production increases the risk for Trichinella spp. infections, since animals can acquire the infection by feeding on carcasses or the offal of hunted or dead wild animals. The awareness and education of hunters and farmers is extremely important to reduce the transmission among free ranging pigs and the risk for humans. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Life cycle variation of Myzus persicae (Hemiptera: Aphididae) in Greece. (United States)

    Margaritopoulos, J T; Tsitsipis, J A; Goudoudaki, S; Blackman, R L


    During the years 1995-1999 the life cycle category of 2797 clones of Myzus persicae (Sulzer) was examined. The clones originated from primary and secondary hosts from different localities of North and Central Greece and the island of Crete in the south. Four different overwintering life cycle strategies were found that have also been described for M. persicae and other heteroecious species previously. A geographical variation was found in the proportion of holocyclic clones from tobacco and other secondary hosts associated with the abundance of the primary host in the sampling regions. In Central Macedonia, around the main peach-growing regions, the proportion of holocyclic clones was mostly above 50% and in some cases reached 100%. In localities of East Macedonia, holocyclic clones were also frequent. On the other hand, further south or in north-eastern Greece, where peach is not common, the proportion of holocyclic clones varied between 0 and 33%. Fifty seven percent of examined anholocyclic clones produced males under short day conditions, suggesting that androcyclic clones in Greece represent an important factor of genetic variability. Intermediate clones were sampled from all host-plants but at low frequencies (3.6% of total examined clones and 6.9% of non-holocyclic ones). Moreover, a regional variation was found in different colour forms feeding on tobacco plants. Red clones were predominant in regions where aphids overwinter parthenogenetically on weeds or winter crops. However, almost all clones from the primary host were green. The ecological aspects of life cycle variation are discussed.

  20. Structure and genetic mechanisms of the Precambrian rifts of the East-European Platform in Russia by integrated study of seismic, gravity, and magnetic data (United States)

    Kostyuchenko, S. L.; Egorkin, A. V.; Solodilov, L. N.


    Integrated models of the deep structure and origin of rifts located within the Russian portion of the East-European Platform have been developed from recent DSS results, new gravity and magnetic modelling, and geological and older geophysical data acquired over the last 50 years. The Mezen rift province, the Middle-Russian rift, the Valday rift, the Pachelma rift, and the rifts within the Pre-Caspian depression were studied. All of these rifts were affected by extension and filled with syn-rift sediments at different times through the Riphean (1650-650 Ma). Post-rift sedimentary basins developed from the end of the Neoproterozoic until the Cenozoic. The models indicate that the crustal structure and genesis of the individual rifts are different. The Mezen rift province was formed under a condition of limited extension of the continental crust. The McKenzie pure strain mechanism is acceptable for lithosphere extension in the Middle-Russian rift. The Wernicke model best expresses the Valday and Pachelma rifts. The rift process in the Pre-Caspian area is explained in terms of large-scale sliding apart of lithospheric plates, and approached the stage of development of oceanic crust.

  1. Proterozoic orogenic belts and rifting of Indian cratons: Geophysical constraints

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    D.C. Mishra


    Full Text Available The Aravalli–Delhi and Satpura Mobile Belts (ADMB and SMB and the Eastern Ghat Mobile Belt (EGMB in India form major Proterozoic mobile belts with adjoining cratons and contemporary basins. The most convincing features of the ADMB and the SMB have been the crustal layers dipping from both sides in opposite directions, crustal thickening (∼45 km and high density and high conductivity rocks in upper/lower crust associated with faults/thrusts. These observations indicate convergence while domal type reflectors in the lower crust suggest an extensional rifting phase. In case of the SMB, even the remnant of the subducting slab characterized by high conductive and low density slab in lithospheric mantle up to ∼120 km across the Purna–Godavari river faults has been traced which may be caused by fluids due to metamorphism. Subduction related intrusives of the SMB south of it and the ADMB west of it suggest N–S and E–W directed convergence and subduction during Meso–Neoproterozoic convergence. The simultaneous E–W convergence between the Bundelkhand craton and Marwar craton (Western Rajasthan across the ADMB and the N–S convergence between the Bundelkhand craton and the Bhandara and Dharwar cratons across the SMB suggest that the forces of convergence might have been in a NE–SW direction with E–W and N–S components in the two cases, respectively. This explains the arcuate shaped collision zone of the ADMB and the SMB which are connected in their western part. The Eastern Ghat Mobile Belt (EGMB also shows signatures of E–W directed Meso–Neoproterozoic convergence with East Antarctica similar to ADMB in north India. Foreland basins such as Vindhyan (ADMB–SMB, and Kurnool (EGMB Supergroups of rocks were formed during this convergence. Older rocks such as Aravalli (ADMB, Mahakoshal–Bijawar (SMB, and Cuddapah (EGMB Supergroups of rocks with several basic/ultrabasic intrusives along these mobile belts, plausibly formed during

  2. Style and ideology: The cold war 'blend' in Greece

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    Romanu Keti


    Full Text Available This paper describes cultural policy in Greece from the end of World War II up to the fall of the junta of colonels in 1974. The writer's object is to show how the Cold War favoured defeated Western countries, which participated effectively in the globalisation of American culture, as in the Western world de-nazification was transformed into a purge of communism. Using the careers of three composers active in communist resistance organizations as examples (Iannis Xenakis, Mikis Theodorakis and Alecos Xenos, the writer describes the repercussions of this phenomenon in Greek musical life and creativity.

  3. Satellite spectral data and archaeological reconnaissance in western Greece (United States)

    Cooper, Frederick A.; Bauer, M. E.; Cullen, Brenda C.


    A Macro-geographical reconnaissance of the Western Peloponnesos adopts spectral signatures taken by Landsat-5 Thematic Mapper as a new instrument of archaeological survey in Greece. Ancient records indicate that indigenous resources contributed to the prosperity of the region. Natural resources and Ancient, Medieval, and Pre-modern Folklife in the Western Peloponnesos describes the principal lines of research. For a supervised classification of attested ancient resources, a variety of biophysical surface features were pinpointed: stone quarries, coal mines, forests of oak and silver fir, terracotta-producing clay beds, crops, and various wild but exploited shrubs such as flax.

  4. The disease burden of chronic obstructive pulmonary disease in Greece

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    Kourlaba G


    Full Text Available Georgia Kourlaba,1 Georgios Hillas,2 Theodoros Vassilakopoulos,2 Nikos Maniadakis3 1Evroston LP, 2Department of Critical Care of Evangelismos Hospital, Medical School of National & Kapodistrian University of Athens, 3Department of Health Services Organization and Management, National School of Public Health, Athens, Greece Background: The objective of the study was to estimate the self-reported prevalence of chronic obstructive pulmonary disease (COPD in Greece and to quantify its burden on patients’ daily activities, productivity, and psychological status. Methods: A population-based, random digit-dialed telephone nationwide survey was conducted between July 10, 2015 and July 31, 2015 in order to recruit patients with COPD in Greece. Among the 11,471 persons contacted, 3,414 met the inclusion criterion of age ≥40 years and completed the screening questions regarding COPD. Of the 362 subjects who reported that they had been diagnosed with COPD, 351 completed the survey. Data on demographic and lifestyle characteristics, comorbidities, disease history, perceived disease severity, breathlessness severity, symptoms severity, limitations in daily activities, psychological distress, and productivity were collected. All data were collected through the telephone interview method using a structured questionnaire. Results: The overall self-reported COPD prevalence was 10.6%. Among 351 participants, only 9% reported that they suffered from severe breathlessness. The mean COPD assessment test score was 19.0, with 84% of participants having a COPD assessment test score ≥10. As for the perceived severity of COPD, the majority of subjects considered that their respiratory condition was of moderate (34.2% or mild severity (33.9%. Overall, the participants reported a significant impact of COPD on their daily life. For instance, 61.5% of them reported that their respiratory condition has affected their sports activities. Moreover, 73% of subjects

  5. How Greece handles Europe's worst lignite

    Energy Technology Data Exchange (ETDEWEB)


    Mainland Greece receives 71% of its electricity from lignite-firing. Although the lignite is some of the poorest-quality coal found in Europe, these power stations have found ways to successfully burn this fuel. The article profiles the St. Dimitrios and Megalopolis power stations, and in particular their technology for successful lignite combustion. Aspects covered include: water-washing lances to remove large deposits of ash from the air heater; warm air blowers and heating coils in bunkers to overcome winter freezing; cooling system-corrosion; and planned pollution control equipment e.g. low-NO[sub x] burners and lime injection downstream of the furnace. 1 fig., 6 photos.

  6. Tot Graeci Tot Sententiae: Astronomical Perspective Multiplicity in Ancient Greece (United States)

    Longo, O.


    Ancient Greece was made of a multiplicity of thinking heads, in an atmosphere of (relative) freedom of opinions, in every field of knowledge. then we should not wonder if many astronomical and cosmological theories, survived until our 17th century, had already been formulated by different philosophers and in different regions, cities and periods of Greek history. Geocentric and heliocentric theories, as well as an atomistic theory of an infinite universe (with infinite worlds), could survive without crashing with one another. In the same time, religious opinions regarding the planets and Sun as a series of gods were present, however not on a scientific ground.

  7. Greece and the refugee crisis: mental health context. (United States)

    Christodoulou, George N; Abou-Saleh, Mohammed T


    The recent influx of refugees and immigrants to Greece has coincided with the ongoing and deteriorating financial crisis. This situation does not allow the Greek authorities to provide help to the desired extent. Yet, the church, local communities, medical societies and non-governmental organisations are offering good psychosocial support. In parallel with support for refugees it is important to provide support for the citizens of the host country. The rich countries of northern Europe should help the poorer countries of southern Europe cope with the refugees. A number of important declarations on refugee mental health and related issues have been produced recently, including the Anti-war Declaration of Athens.

  8. Towards the understanding of tropospheric noise in InSAR data based on combined GPS and meteorological data (United States)

    Moschas, Fanis; Saltogianni, Vasso; Yannopoulos, Panayotis; Stiros, Stathis


    An array of GPS/GNSS stations has been established in order to investigate the hydrological bias in satellite positioning signals in various meteorological conditions. The study area is next to the Patraikos and Corinth Gulf (NW Peloponnese, Greece), which is characterized by a spatio-temporal sequences of hydro-atmospheric effects, from snow to sunshine, due to its particular geography and topography. The idea is to analyze GNSS recordings from stations with very high vertical separation (with altitude up to 1600m and with a gradient of up to 20%) as well as collocated and nearby stations, so that there is some control in both the vertical and the horizontal variability of the atmospheric effects, and also a control in the noise of geodetic sensors. Results from GPS data are planned to be combined with meteorological data, as well as satellite radar data, in order to evaluate tropospheric noise in InSAR. This project takes advantage of GPS stations established in wider study area in the framework of the Corinth Rift Laboratory ( and has been partly funded by the PLATO Project of the Greek Secretariat for Research and Technology.

  9. Morphometric and magmatic evolution at the Boset-Bericha Volcanic Complex in the Main Ethiopian Rift (United States)

    Siegburg, Melanie; Gernon, Thomas; Bull, Jonathan; Keir, Derek; Taylor, Rex; Nixon, Casey; Abebe, Bekele; Ayele, Atalay


    Tectono-magmatic interactions are an intrinsic feature of continental rifting and break up in the Main Ethiopian Rift (MER). The Boset-Bericha volcanic complex (BBVC) is one of the largest stratovolcanoes in the MER (with a total area of ˜870 km2), with volcanism largely occurring over the last ˜2 Myr. Despite the fact that 4 million people live within 100 km of the volcano, little is known about its eruptive history and how the volcanic system interacts with rift valley tectonics. Here, we present a detailed relative eruption chronology combined with morphometric analyses of different elements of the volcanic complex and petrological analyses to constrain morphometric and magmatic evolution at the BBVC. Additionally, tectonic activity has been characterised around the BBVC, all based on field observations and mapping using high-resolution digital elevation data. The BBVC consists of the Gudda Volcano and the younger Bericha Volcano, two silicic eruption centres located along the NNE-SSW trending rift axis. The fault population predominantly comprises distributed extensional faults parallel to the rift axis, as well as localised discrete faults with displacements of up to 50 m in the rift centre, and up to 200 m in the NE-SW trending border fault system. Multiple cones, craters and fissure systems are also oriented parallel to the rift axis, i.e. perpendicular to the minimum compressive stress. The eruption history of BBVC can be differentiated into 5 main eruption stages, subdivided into at least 12 eruptive phases with a total of 128 mappable lava flows. Crosscutting relationships of lava flows provide a relative chronology of the eruptive history of the BBVC, starting with pre-BBVC rift floor basalts, pre-caldera and caldera activity, three post-caldera phases at the Gudda Volcano and two phases forming the Bericha Volcano. At least four fissure eruption phases occurred along the rift axis temporally in between the main eruptive phases. Morphometric analyses

  10. Initiation and development of the Kivu rift segment in Central Africa by reactivating un-favorably oriented structural weaknesses (United States)

    Delvaux, Damien; Smets, Benoît


    The Kivu rift region forms the central segment of the western branch of the East African rift system, between the northern termination of the Tanganyika rift and the southern extension of the Edward-George rift. Its structure and geological evolution has been revised in the light of a compilation of existing data on earthquake epicenters, focal depth, focal mechanisms, thermal springs and neotectonic faults. It has long been shown that the link between the Kivu rift basin and the Northern termination of the Tanganyika rift basin forms an accommodation zone in which the Rusizi tectonic depression occupies a central place (Ebinger, 1989). In addition, our compilation suggests that the NNE-trending Kivu rift basin and the N-S northern half of the Tanganyika rift basin initiated as separated, partly overlapping and differently oriented basins. The orientation and development of the Kivu rift basin was controlled by an inferred Mid-Proterozoic crustal shear zone and a Pan-African reverse fault front. It was not optimally oriented with the general (first-order) stress field characterized by roughly E-W extension. In a later stage, the more optimally N-S oriented North Tanganyika basin progressed towards the North and connected to Kivu rift in its middle in a region now occupied by the town of Bukavu. This accommodation zone is marked by Quaternary volcanism, warm thermal springs, frequent and relatively shallow seismicity. The southwestern part of the Kivu rift became progressively abandoned but it is still seismically active and hosts a number of warm thermal springs. This particular architecture influences the present-day stress field. This work is a contribution to the Belgian GeoRisCA project. Ebinger, C.J. 1989. Geometric and kinematic development of border faults and accommodation zones, Kivu-Rusizi Rift, Africa. Tectonics, 8, 117-133

  11. Spatial and Temporal Population Genetics at Deep-Sea Hydrothermal Vents Along the East Pacific Rise and Galapagos Rift (United States)


    Pacific Rise and Galapagos Rift by Abigail Jean Fusaro September 2008 20081117239 50? 𔃼-101 REPORT DOCUMENTATION PAGE 1. REPORT NO. MIT/WHOI...Pacific Rise and Galapagos Rift 5. Report Date September 2008 6. ?. uthor(s) . Abigail Jean husaro 8. Performing Organization...2008. Spatial and Temporal Population Genetics at Deep-Sea Hydrothermal Vents Along the East Pacific Rise and Galapagos Rift. Ph.D. Thesis. MITAVHOI

  12. Sustaining without Changing: The Metabolic Rift of Certified Organic Farming

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    Julius Alexander McGee


    Full Text Available Many proponents of organic farming claim that it is a sustainable alternative to conventional agriculture due to its reliance on natural agro-inputs, such as manure based fertilizers and organic pesticides. However, in this analysis we argue that although particular organic farming practices clearly benefit ecosystems and human consumers, the social context in which some organic farms develop, limit the potential environmental benefits of organic agriculture. Specifically, we argue that certified organic farming’s increased reliance on agro-inputs, such as organic fertilizers and pesticides, reduces its ability to decrease global water pollution. We review recent research that demonstrates the environmental consequences of specific organic practices, as well as literature showing that global organic farming is increasing its reliance on agro-inputs, and contend that organic farming has its own metabolic rift with natural water systems similar to conventional agriculture. We use a fixed-effects panel regression model to explore how recent rises in certified organic farmland correlate to water pollution (measured as biochemical oxygen demand. Our findings indicate that increases in the proportion of organic farmland over time increases water pollution. We conclude that this may be a result of organic farms increasing their reliance on non-farm agro-inputs, such as fertilizers.

  13. The North Galactic Pole Rift and the Local Hot Bubble (United States)

    Snowden, S. L.; Koutroumpa, D.; Kuntz, K. D.; Lallement, R.; Puspitarini, L.


    The North Galactic Pole Rift (NGPR) is one of the few distinct neutral hydrogen clouds at high Galactic latitudes that have well-defined distances. It is located at the edge of the Local Cavity (LC) and provides an important test case for understanding the Local Hot Bubble (LHB), the presumed location for the hot diffuse plasma responsible for much of the observed 1/4 keV emission originating in the solar neighborhood. Using data from the ROSAT All- Sky Survey and the Planck reddening map, we find the path length within the LC (LHB plus Complex of Local Interstellar Clouds) to be 98 plus or minus 27 pc, in excellent agreement with the distance to the NGPR of 98 +/- 6 pc. In addition, we examine another 14 directions that are distributed over the sky where the LC wall is apparently optically thick at 1/4 keV. We find that the data in these directions are also consistent with the LHB model and a uniform emissivity plasma filling most of the LC.

  14. Middle Stone Age starch acquisition in the Niassa Rift, Mozambique (United States)

    Mercader, Julio; Bennett, Tim; Raja, Mussa


    The quest for direct lines of evidence for Paleolithic plant consumption during the African Middle Stone Age has led scientists to study residues and use-wear on flaked stone tools. Past work has established lithic function through multiple lines of evidence and the spatial breakdown of use-wear and microscopic traces on tool surfaces. This paper focuses on the quantitative analysis of starch assemblages and the botanical identification of grains from flake and core tools to learn about human ecology of carbohydrate use around the Niassa woodlands, in the Mozambican Rift. The processing of starchy plant parts is deduced from the occurrence of starch assemblages that presumably got attached to stone tool surfaces by actions associated with extractive or culinary activities. Specifically, we investigate starch grains from stone tools recently excavated in northern Mozambique at the site of Mikuyu; which presumably spans the middle to late Pleistocene and represents similar sites found along the Malawi/Niassa corridor that links East, Southern, and Central Africa. Starch was extracted and processed with a diverse tool kit consisting of scrapers, cores, points, flakes, and other kinds of tools. The microbotanical data suggests consumption of seeds, legumes, caryopses, piths, underground storage organs, nuts, and mesocarps from more than a dozen families. Our data suggest a great antiquity for starch use in Africa as well as an expanded diet and intensification.

  15. A dynamic, climate-driven model of Rift Valley fever

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    Joseph Leedale


    Full Text Available Outbreaks of Rift Valley fever (RVF in eastern Africa have previously occurred following specific rainfall dynamics and flooding events that appear to support the emergence of large numbers of mosquito vectors. As such, transmission of the virus is considered to be sensitive to environmental conditions and therefore changes in climate can impact the spatiotemporal dynamics of epizootic vulnerability. Epidemiological information describing the methods and parameters of RVF transmission and its dependence on climatic factors are used to develop a new spatio-temporal mathematical model that simulates these dynamics and can predict the impact of changes in climate. The Liverpool RVF (LRVF model is a new dynamic, process-based model driven by climate data that provides a predictive output of geographical changes in RVF outbreak susceptibility as a result of the climate and local livestock immunity. This description of the multi-disciplinary process of model development is accessible to mathematicians, epidemiological modellers and climate scientists, uniting dynamic mathematical modelling, empirical parameterisation and state-of-the-art climate information.

  16. An Assembly Model of Rift Valley Fever Virus (United States)

    Rusu, Mirabela; Bonneau, Richard; Holbrook, Michael R.; Watowich, Stanley J.; Birmanns, Stefan; Wriggers, Willy; Freiberg, Alexander N.


    Rift Valley fever virus (RVFV) is a bunyavirus endemic to Africa and the Arabian Peninsula that infects humans and livestock. The virus encodes two glycoproteins, Gn and Gc, which represent the major structural antigens and are responsible for host cell receptor binding and fusion. Both glycoproteins are organized on the virus surface as cylindrical hollow spikes that cluster into distinct capsomers with the overall assembly exhibiting an icosahedral symmetry. Currently, no experimental three-dimensional structure for any entire bunyavirus glycoprotein is available. Using fold recognition, we generated molecular models for both RVFV glycoproteins and found significant structural matches between the RVFV Gn protein and the influenza virus hemagglutinin protein and a separate match between RVFV Gc protein and Sindbis virus envelope protein E1. Using these models, the potential interaction and arrangement of both glycoproteins in the RVFV particle was analyzed, by modeling their placement within the cryo-electron microscopy density map of RVFV. We identified four possible arrangements of the glycoproteins in the virion envelope. Each assembly model proposes that the ectodomain of Gn forms the majority of the protruding capsomer and that Gc is involved in formation of the capsomer base. Furthermore, Gc is suggested to facilitate intercapsomer connections. The proposed arrangement of the two glycoproteins on the RVFV surface is similar to that described for the alphavirus E1-E2 proteins. Our models will provide guidance to better understand the assembly process of phleboviruses and such structural studies can also contribute to the design of targeted antivirals. PMID:22837754

  17. An assembly model of Rift Valley fever virus

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    Mirabela eRusu


    Full Text Available Rift Valley fever virus (RVFV is a bunyavirus endemic to Africa and the Arabian Peninsula that infects humans and livestock. The virus encodes two glycoproteins, Gn and Gc, which represent the major structural antigens and are responsible for host cell receptor binding and fusion. Both glycoproteins are organized on the virus surface as cylindrical hollow spikes that cluster into distinct capsomers with the overall assembly exhibiting an icosahedral symmetry. Currently, no experimental three-dimensional structure for any entire bunyavirus glycoprotein is available. Using fold recognition, we generated molecular models for both RVFV glycoproteins and found significant structural matches between the RVFV Gn protein and the influenza virus hemagglutinin protein and a separate match between RVFV Gc protein and Sindbis virus envelope protein E1. Using these models, the potential interaction and arrangement of both glycoproteins in the RVFV particle was analyzed, by modeling their placement within the cryo-electron microscopy density map of RVFV. We identified four possible arrangements of the glycoproteins in the virion envelope. Each assembly model proposes that the ectodomain of Gn forms the majority of the protruding capsomer and that Gc is involved in formation of the capsomer base. Furthermore, Gc is suggested to facilitate intercapsomer connections. The proposed arrangement of the two glycoproteins on the RVFV surface is similar to that described for the alphavirus E1-E2 proteins. Our models will provide guidance to better understand the assembly process of phleboviruses and such structural studies can also contribute to the design of targeted antivirals.

  18. Butterfly Species Richness in Selected West Albertine Rift Forests

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    Patrice Kasangaki


    Full Text Available The butterfly species richness of 17 forests located in the western arm of the Albertine Rift in Uganda was compared using cluster analysis and principal components analysis (PCA to assess similarities among the forests. The objective was to compare the butterfly species richness of the forests. A total of 630 butterfly species were collected in 5 main families. The different species fell into 7 ecological groupings with the closed forest group having the most species and the swamp/wetland group with the fewest number of species. Three clusters were obtained. The first cluster had forests characterized by relatively high altitude and low species richness despite the big area in the case of Rwenzori and being close to the supposed Pleistocene refugium. The second cluster had forests far away from the supposed refugium except Kisangi and moderate species richness with small areas, whereas the third cluster had those forests that were more disturbed, high species richness, and low altitudinal levels with big areas.

  19. Stress Rotation in the Kachchh Rift Zone, Gujarat, India (United States)

    Mandal, Prantik


    Double difference relocations of the 1402 Kachchh events (2001 2006) clearly delineate two fault zones viz. south-dipping North Wagad fault (NWF) and almost vertical Gedi fault (GF). The relocated focal depths delineate a marked variation of 4 and 7 km in the brittle-ductile transition depths beneath GF and NWF, respectively. The focal mechanism solutions of 464 aftershocks (using 8 12 first motions) show that the focal mechanisms ranged between pure reverse and pure strike-slip except for a few pure dip-slip solutions. The stress inversions performed for five rectangular zones across the Kachchh rift reveal both clockwise and anticlockwise rotation (7 32°) in the σ1 orientation within the rupture zone, favoring a heterogeneous stress regime with an average N-S fault normal compression. This rotation may be attributed to the presence of crustal mafic intrusives (5 35 km depth) in the rupture zone of the 2001 Bhuj main shock. Results suggest a relatively homogeneous stress regime in the GF zone favoring strike-slip motion, with a fault normal N-S compression.

  20. A global census of continental rift activity since 250 Ma reveals a missing element of the deep carbon cycle (United States)

    Brune, Sascha; Williams, Simon; Müller, Dietmar


    The deep carbon cycle connects CO2 concentrations within the atmosphere to the vast carbon reservoir in Earth's mantle: subducted lithosphere carries carbon into the mantle, while extensional plate boundaries and arc volcanoes release it back to Earth's surface. The length of plate boundaries thereby exerts first-order control on global CO2 fluxes on geological time scales. Here we provide a global census of rift length from the Triassic to present day, combining a new plate reconstruction analysis technique with data from the geological rift record. We find that the most extensive rift phase during the fragmentation of Pangea occurred in the Jurassic/Early Cretaceous with extension along the South Atlantic (9700 km) and North Atlantic rifts (9100 km), within East Gondwana (8500 km), the failed African rift systems (4900 km), and between Australia and Antarctica (3700 km). The combined extent of these and other rift systems amounts to more than 50.000 km of simultaneously active continental rifts. During the Late Cretaceous, in the aftermath of this massive rift episode, the global rift length dropped by 60% to 20.000 km. We further show that a second pronounced rift episode starts in the Eocene with global rift lengths of up to 30.000 km. It is well-accepted that volcanoes at plate boundaries release large amounts of CO2 from the Earth's interior. Recent work, however, highlights the importance of deep-cutting faults and diffuse degassing on CO2 emissions in the East African Rift, which appear to be comparable to CO2 release rates at mid-ocean ridges worldwide. Upscaling measured CO2 fluxes from East Africa to all concurrently active global rift zones with due caution, we compute the first-order history of cumulative rift-related CO2 degassing rates for the last 250 Myr. We demonstrate that rift-related CO2 release in the Early Cretaceous may have reached 400% of present-day rates. In first-order agreement with paleo-atmospheric CO2 concentrations from proxy

  1. Re-orientation of the extension direction and pure extensional faulting at oblique rift margins: Comparison between the Main Ethiopian Rift and laboratory experiments

    NARCIS (Netherlands)

    Corti, G.; Philippon, M.|info:eu-repo/dai/nl/370818636; Sani, F.; Keir, D.; Kidane, T.


    In this study, we draw on a unique combination of well-resolved fault-slip data and earthquake focal mechanisms to constrain spatial variations in style of faulting in the obliquely extending Main Ethiopian Rift, East Africa. These data show that both boundary and internal faults - oblique and

  2. Synergy of ASAR and RADARSAT-2 ultra-fine acquisitions for ground deformation monitoring by means of DInSAR and PSI (United States)

    Elias, Panagiotis; Briole, Pierre; Sykioti, Olga


    The Gulf of Corinth study area has been long identified as a site of major importance due to its intense past geophysical activity. It is one of the world's most rapidly extending continental regions and it has one of the highest seismicity rates in the Euro-Mediterranean region, having produced a number of earthquakes with magnitude greater than 5.8: Alkyonides (1981, M=6.7), Aigio (1995, Mw=6.1), and Galaxidi (1992, Mw=5.8). Moreover, the geodetic studies conducted, which were based on GPS observations and InSAR calculations, revealed north - south extension rates across the gulf of up to about 1.5 cm year-1 during the last 20 years. Moreover the south coast of the Corinth rift is uplifting whereas the north part is subsiding. The rifting mechanism observed is crucial for the stability of the region as it can lead to submarine slope failures and possible damaging tsunamis. On land, the same fault system causes landslides. The area or the Gulf of Corinth that presents a major scientific and/or socio-economic interest is Patras broader area, the Psathopyrgos fault zone which is considered to be a presently active structure, the Rion-Patras fault zone, the city of Patras and the Rion-Antirion bridge. Psathopyrgos fault zone acts as a transfer zone between the Corinth and Patras rift. Recently on June 8th, 2008 a Mw=6.4 earthquake occurred in NW Peloponnesus, western Greece, at a distance of 17km southwest of the city of Patras. This event is the largest strike-slip earthquake to occur in western Greece during the past 25 years. The days following the main shock, the seismicity were propagating northward towards the city of Patras. Static (Coulomb) stress transfer analysis indicates loading of faults near the city of Patras. Patras is the third most populated city in Greece with more that 200,000 citizens. The bridge of Rion-Antirion is 2,880m long (its width is 28m) and connects the eastern and western Greece. The bridge has been designed and constructed taking into

  3. Permo-Triassic anatexis, continental rifting and the disassembly of western Pangaea (United States)

    Cochrane, Ryan; Spikings, Richard; Gerdes, Axel; Ulianov, Alexey; Mora, Andres; Villagómez, Diego; Putlitz, Benita; Chiaradia, Massimo


    Crustal anatectites are frequently observed along ocean-continent active margins, although their origins are disputed with interpretations varying between rift-related and collisional. We report geochemical, isotopic and geochronological data that define an ~ 1500 km long belt of S-type meta-granites along the Andes of Colombia and Ecuador, which formed during 275-223 Ma. These are accompanied by amphibolitized tholeiitic basaltic dykes that yield concordant zircon U-Pb dates ranging between 240 and 223 Ma. A model is presented which places these rocks within a compressive Permian arc setting that existed during the amalgamation of westernmost Pangaea. Anatexis and mafic intrusion during 240-223 Ma are interpreted to have occurred during continental rifting, which culminated in the formation of oceanic crust and initiated the break-up of western Pangaea. Compression during 275-240 Ma generated small volumes of crustal melting. Rifting during 240-225 Ma was characterized by basaltic underplating, the intrusion of tholeiitic basalts and a peak in crustal melting. Tholeiitic intrusions during 225-216 Ma isotopically resemble depleted mantle and yield no evidence for contamination by continental crust, and we assign this period to the onset of continental drift. Dissected ophiolitic sequences in northern Colombia yield zircon U-Pb dates of 216 Ma. The Permo-Triassic margin of Ecuador and Colombia exhibits close temporal, faunal and geochemical similarities with various crustal blocks that form the basement to parts of Mexico, and thus these may represent the relict conjugate margin to NW Gondwana. The magmatic record of the early disassembly of Pangaea spans ~ 20 Ma (240-216 Ma), and the duration of rifting and rift-drift transition is similar to that documented in Cretaceous-Tertiary rift settings such as the West Iberia-Newfoundland conjugate margins, and the Taupo-Lau-Havre System, where rifting and continental disassembly also occurred over periods lasting ~ 20 Ma.

  4. Decadal changes in extreme daily precipitation in Greece

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    P. T. Nastos


    Full Text Available The changes in daily precipitation totals in Greece, during the 45-year period (1957–2001 are examined. The precipitation datasets concern daily totals recorded at 21 surface meteorological stations of the Hellenic National Meteorological Service, which are uniformly distributed over the Greek region. First and foremost, the application of Factor Analysis resulted in grouping the meteorological stations with similar variation in time. The main sub groups represent the northern, southern, western, eastern and central regions of Greece with common precipitation characteristics. For representative stations of the extracted sub groups we estimated the trends and the time variability for the number of days (% exceeding 30 mm (equal to the 95% percentile of daily precipitation for eastern and western regions and equal to the 97.5% percentile for the rest of the country and 50 mm which is the threshold for very extreme and rare events. Furthermore, the scale and shape parameters of the well fitted gamma distribution to the daily precipitation data with respect to the whole examined period and to the 10-year sub periods reveal the changes in the intensity of the precipitation.

  5. Energy Payback Time of a Rooftop Photovoltaic System in Greece (United States)

    Rachoutis, E.; Koubogiannis, D.


    Life Cycle Analysis (LCA) is an important tool to quantitatively assess energy consumption and environmental impact of any product. Current research related to energy consumption in buildings moves towards Nearly Zero Energy Building (NZEB). In such a building, an important issue concerns the energy production by renewable sources, including on-site production. The most feasible way to achieve renewable energy utilization in a building level in Greece is by using rooftop Photovoltaic (PV) systems, also promoted in the last decade by the national legislation concerning energy conservation measures. Apart from cost-related issues and payback times, Embodied Energy (EE) and Embodied CO2 (ECO2) emissions have also to be considered against the anticipated corresponding savings. Using a particular PV system as a case study, its basic constitutive materials are determined and their masses are calculated. Embodied energy values are estimated by using embodied energy coefficients available in the international literature. Considering a specific geographic location in Greece for the building on which the PV is installed, the annual energy generated by the system is estimated based on its performance data and curves. The Energy and CO2 Payback Times (EPBT and CO2PBT) are estimated and assessed, as well as future work is suggested.

  6. Euthanasia in Greece: Greek nurses' involvement and beliefs. (United States)

    Patelarou, Evridiki; Vardavas, Constantine I; Fioraki, Ioanna; Alegakis, Thanasis; Dafermou, Maria; Ntzilepi, Penelope


    Euthanasia has become a prominent social and ethical issue in which nurses play an important role. This study evaluated, for the first time in Greece, the acceptance and enactment of passive euthanasia among Greek nursing staff, measured in relation to the type of patients cared for. Passive euthanasia, illegal in Greece, is defined as either withdrawing or withholding life-sustaining treatment. Fifty-one per cent responded that they would not be willing to withhold life-sustaining treatment if legalized, while almost 30% responded that they had withheld life-sustaining treatment from a patient at least once in the past; specifically 47.7% of intensive care unit nurses (OR 8.2; 95% CI: 1.6-41.3), 20% of cancer ward nurses (OR 2.7; 95% CI: 0.5-15.6) and 8.3% of other nurses from other wards (P = 0.001). Age, gender and self-reported levels of religiosity among Greek nurses were not found to affect statistically any variable regarding euthanasia and its enactment.

  7. The number and its symbolism in ancient Greece

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    Doc. dr Milena Bogdanović


    Full Text Available The symbols are of particular importance. They are the heart of the creative life; rather they are its core. They reveal the secrets of the unconscious mind open to the unknown and the infinite. While talking or gestures while express, we use the symbols, noting it or not. All spiritual science, all art and all art techniques encounter on their way symbols. History confirms that the symbols of each object can be obtained symbolic value, whether natural (rocks, trees, animals, planets, fire, lightning, etc... or abstract (geometrical shape, number, pace, ideas, etc.... The use of numbers as symbols is as old as language itself, but one that precedes writing, which symbolize numbers (that is, where the reality behind the external characters. The sheer numbers and their symbolism in ancient Greece and is closely associated with the philosophy and mathematics (namely arithmetic. They summarize their view of the world and everything around them. This paper draws attention to the symbolism of the numbers that were in ancient Greece.

  8. Service quality perceptions in primary health care centres in Greece. (United States)

    Papanikolaou, Vicky; Zygiaris, Sotiris


    The paper refers to the increased competition between health care providers and the need for patient-centred services in Greece. Using service quality methodology, this paper investigates service quality perceptions of patients in Greek public primary health centres. To test the internal consistency and applicability of SERVQUAL in primary health care centres in Greece. SERVQUAL was used to examine whether patients have different expectations from health care providers and whether different groups of patients may consider some dimensions of care more important than others. The analysis showed that there were gaps in all dimensions measured by SERVQUAL. The largest gap was detected in empathy. Further analysis showed that there were also differences depending on gender, age and education levels. A separate analysis of expectations and perceptions revealed that this gap was because of differences in patients' perceptions rather than expectations. THIS paper raises a number of issues that concern the applicability of SERVQUAL in health care services and could enhance current discussions about SERVQUAL improvement. Quality of health care needs to be redefined by encompassing multiple dimensions. Beyond a simple expectations-perceptions gap, people may hold different understandings of health care that, in turn, influence their perception of the quality of services. © 2012 John Wiley & Sons Ltd.

  9. Shame and Anxiety Feelings of a Roma Population in Greece. (United States)

    Gouva, M; Mentis, M; Kotrotsiou, S; Paralikas, Th; Kotrotsiou, E


    Shame is a crucial issue for Roma. The purpose of the present study was to evaluate the severity of shame and anxiety feelings in a Roma population living in Greece and assess the differentiation of these feelings between Roma men and women. A quota sample of 194 Roma adult men and women living in Southern Greece was retrieved. The Experiences of Shame Scale (ESS), the Other As Shamer Scale (OAS) and the Spielberg's State/Trait Anxiety Inventory (STAI) questionnaires were used. Women scored statistically significantly higher than men on ESS, whereas men scored higher on OAS scale (52.27 ± 16.91 vs 45.42 ± 9.98 and 35.93 ± 16.94 vs 30.87 ± 13.72 respectively). Women scored higher than men in both STAI subscales, however significant differences were observed only in State Anxiety scale (48.83 ± 9.26 vs 43.20 ± 9.81). OAS total score was inversely related to state anxiety, whereas ESS total score was positive related to trait anxiety, all correlations being significant at p shame and anxiety. Cultural, social and minority issues contribute to feelings of inferiority and anxiety experience.

  10. Top Income Shares in Greece: 1957-2010

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    Kostas Chrissis


    Full Text Available This paper analyses the evolution of top income shares in Greece for the period 1957 to 2010 following Piketty (2001 methodology. We present the 10%, 5%, 2.5%, 2%, 1.5%, 1%, 0.5% and 0.1% income shares estimates which are based on tax statistics. The empirical results indicate that the behavior of the alternative estimated top income shares is quite similar. A ‘flat’ Ushaped pattern for most cases seems to exist. This common pattern is more apparent for the 2.5-0.1% top income shares. The top 10% and 5% income shares seem to be more volatile, accompanied with an increasing trend by the end of the period. This paper is an attempt to extend the existing research in southern Europe by presenting the relevant Greek experience. For the whole period, country comparisons show that the 1% top income share in Greece is in lower levels than that of USA and the other European countries (Italy, Portugal, Spain, France, Germany.

  11. A clinical and educational telemedicine link between Bulgaria and Greece. (United States)

    Anogianakis, George; Ilonidis, George; Anogeianaki, Antonia; Milliaras, Spyros; Klisarova, Anelia; Temelkov, Temel; Vlachakis-Milliaras, Emmanuel


    During its transition to a free economy, Bulgaria benefited from foreign aid provided by Greece. One of the projects was the clinical and educational telemedicine link between the Medical University of Varna in Bulgaria and the Faculty of Medicine of Aristotle University of Thessaloniki in Greece. This began in 1997. In terms of the educational activities, the Bulgarian side of the network supports (a) electronic design and publishing activities, (b) web hosting and mail server activities and (c) satellite communications. In addition it supports an electronic classroom equipped with personal workstations, multimedia projectors and videoconference facilities. Communications are via the ISDN network. In terms of its telemedicine activities, the network provides remote medical assistance to "language handicapped" travellers and to migrant workers in both countries. The main clinical experience is remote consultations in immunology. This admittedly limited experience demonstrates that telemedicine can be used to provide assistance to remote colleagues. In cases where the patient cannot communicate with the attending physician, the use of telemedicine can greatly improve the quality of care available to travellers and migrant workers.

  12. Service quality perceptions in primary health care centres in Greece (United States)

    Papanikolaou, Vicky; Zygiaris, Sotiris


    Abstract Context  The paper refers to the increased competition between health care providers and the need for patient‐centred services in Greece. Using service quality methodology, this paper investigates service quality perceptions of patients in Greek public primary health centres. Objective  To test the internal consistency and applicability of SERVQUAL in primary health care centres in Greece. Strategy  SERVQUAL was used to examine whether patients have different expectations from health care providers and whether different groups of patients may consider some dimensions of care more important than others. Results  The analysis showed that there were gaps in all dimensions measured by SERVQUAL. The largest gap was detected in empathy. Further analysis showed that there were also differences depending on gender, age and education levels. A separate analysis of expectations and perceptions revealed that this gap was because of differences in patients’ perceptions rather than expectations. Discussion and conclusions  This paper raises a number of issues that concern the applicability of SERVQUAL in health care services and could enhance current discussions about SERVQUAL improvement. Quality of health care needs to be redefined by encompassing multiple dimensions. Beyond a simple expectations–perceptions gap, people may hold different understandings of health care that, in turn, influence their perception of the quality of services. PMID:22296402

  13. Scanning the business external environment for information: evidence from Greece

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    L. Kourteli


    Full Text Available Introduction. This paper examines the business external environment scanning theory for information in the context of Greece. Method. A questionnaire was developed to explore the relationships between general and task business environment, perceived uncertainty, scanning strategy, and sources of information with respect to type of environment, size and industry.The research was based on a sample of 144 private organizations operating in North Greece. Analysis. Data collected were analysed using SPSS. The statistical procedures of chi-squared homogeneity test, ANOVA, Duncan's test of homogeneity of means, and related samples t-test were followed for testing the hypotheses developed. Results. The results show that perceived uncertainty of the general and task business external environment factors depend on the type of the environment, size of organization, and industry where the organizations operate; organizations adapt their scanning strategy to the complexity of the environment; personal sources of information seem to be more important than impersonal sources; external sources of information are equally important with internal sources; and higher levels of environmental uncertainty are associated with higher levels of scanning the various sources. Conclusion. Business external environment scanning of information is influenced by the characteristics of the organizations themselves and by the characteristics of the external environment within which the organizations operate. The study contributes to both environmental scanning theory and has important messages for practitioners.

  14. Reorganisation of Oncologic Care in Greece: A Proposal

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    Emmanouilides Christos


    Full Text Available Cancer is becoming a major public health issue as patients enjoy longer survivals than ever before due to the introduction innovative but expensive drugs in the clinic. In addition, the ageing of the population in Greece is expected to increase the absolute incidence of cancer. The National Health System should rapidly and efficiently adapt to the new challenges, including increased pharmaceutical costs. Resources ought to be allocated rationally and efficiently while maintaining adequate coverage for the insured population. Economising due to large-scale operations should be pursued by the governmental single payor (EOPYY, so that affordable coverage remains feasible. Establishment of mechanisms to deal with new and very costly drugs should be put in place. The major changes in anchor oncologic hospitals are needed in order to play a role as regional leaders in oncologic care, including merging of similar divisions, subspecialisation of services and promotion of clinical research. These major centres could coordinate a host of satellite oncology services in other urban hospitals and in the provinces. In addition, joint operations in training and patient care should be pursued with major private centres, without mutual mistrust or obsolete inflexibilities. The current financial crisis represents an excellent opportunity for revisioning and restructuring oncologic care in Greece, taking into account the societal needs and based on flexibility and efficiency.

  15. Cassini Scientist for a Day: an international contest in Greece (United States)

    Solomonidou, Anezina; Moussas, Xenophon; Xystouris, Georgios; Coustenis, Athena; Lebreton, Jean-Pierre; Katsavrias, Christos; Bampasidis, Georgios; Kyriakopoulos, Konstantinos; Kouloumvakos, Athanasios; Patsou, Ioanna


    The Cassini Outreach Team of NASA's Jet Propulsion Laboratory is being organizing a brilliant school contest in Astronomy focusing in the Saturnian system. This essay contest provides school students all around the worlds with the opportunity to get involved in astronomy and astrophysics and planetary sciences in particular. From 2010 the 'Cassini Scientist for a Day' contest has being one of the most successful as well as important outreach activities of ESA and NASA in Greece with hundreds of participants all over Greece. The number of participants is growing rapidly every year. This type of school competition in Greece is particularly important since Astronomy and Astrophysics and Space Sciences, although very popular, are not included in the school curricula and thus students rarely have the opportunity to experience and participate actively in these subjects. For the years 2010 and 2011, the Space Physics Group of the Astronomy, Astrophysics and Mechanics section of the University of Athens in association with external colleagues has been selected as the co-ordinator of NASA for the competition in Greece. Under the guidance of Cassini Outreach team, the members of the Space Physics Group have informed, explained and spread the rules of the competition at primary, secondary and high schools all over Greece. In general, the students have the option to choose Cassini monitoring between three targets of the Saturnian system, which the participants show that will bring the best scientific result. Their arguments should be summarized in an essay of 500 words more or less. They also have the option to do team work through groups of maximum three students. The participation in the contest for 2010 was unexpectedly high and thoroughly satisfied. The winners awarded through a ceremony which was held in the largest amphitheater at the central building of the University of Athens, that was fully packed. The following year 2011 the participation increased up to 300% while

  16. Thermal and exhumation history of the central Rwenzori Mountains, Western Rift of the East African Rift System, Uganda (United States)

    Bauer, F. U.; Glasmacher, U. A.; Ring, U.; Schumann, A.; Nagudi, B.


    The Rwenzori Mountains (Mtns) in west Uganda are the highest rift mountains on Earth and rise to more than 5,000 m. We apply low-temperature thermochronology (apatite fission-track (AFT) and apatite (U-Th-Sm)/He (AHe) analysis) for tracking the cooling history of the Rwenzori Mtns. Samples from the central and northern Rwenzoris reveal AFT ages between 195.0 (±8.4) Ma and 85.3 (±5.3) Ma, and AHe ages between 210.0 (±6.0) Ma to 24.9 (±0.5) Ma. Modelled time-temperature paths reflect a protracted cooling history with accelerated cooling in Permo-Triassic and Jurassic times, followed by a long period of constant and slow cooling, than succeeded by a renewed accelerated cooling in the Neogene. During the last 10 Ma, differentiated erosion and surface uplift affected the Rwenzori Mtns, with more pronounced uplift along the western flank. The final rock uplift of the Rwenzori Mtns that partly led to the formation of the recent topography must have been fast and in the near past (Pliocene to Pleistocene). Erosion could not compensate for the latest rock uplift, resulting in Oligocene to Miocene AHe ages.

  17. Geological, Mineralogical and Geochemical Aspects for Critical and Rare Metals in Greece

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    Vasilios Melfos


    Full Text Available The European Union (EU is highly dependent on critical and rare metals which are very important for a sustainable development. However, European industry is not able to cover its demands from native sources and it imports commodities from third countries. Greece is one of the EU countries with the most potential for supplying these strategic metallic raw materials in the future, since it hosts a large number of ore deposits. The epithermal- and porphyry-type deposits and the reduced intrusion related systems of the Serbomacedonian and the Rhodope metallogenic provinces in Northeastern Greece are promising targets for a future exploitation and exploration in Sb, Te, Mo, Re, Ga, In, REE and PGE. Greece is the leading producer of Ni and Al in the EU from laterites and bauxites of central and northern Greece. These deposits also contain significant amounts of Co or REE which should be considered in the future plans of the processing industries. REE are found in high contents at the placer deposits between Chalkidiki and Kavala (North Greece and elevated PGE concentrations are associated with the chromitites of northwestern Greece. Therefore, the mineral wealth of Greece can contribute significantly to a sustainable and a competitive economy of Europe.

  18. Tectonic block rotation, arc curvature, and back-arc rifting: Insights into these processes in the Mediterranean and the western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, L M; Ellis, S [GNS Science, PO Box 30368, Lower Hutt (New Zealand); Mann, P [Institute for Geophysics, University of Texas at Austin, Austin, Texas (United States)], E-mail:


    The fastest modern-day tectonic block rotations on Earth (up to 9 degrees/Myr) occur in the forearcs of convergent plate margins where a transition from collision of a bathymetric high to subduction of normal oceanic crust occurs. GPS techniques have enabled accurate documentation of the kinematics of these rotations, leading us to develop a conceptual model where the change from collision to subduction exerts a torque on microplates within the plate boundary zone, causing them to spin rapidly about an axis at the collision point. We have investigated geophysical and geological data from several active plate boundaries (from the western Pacific and Mediterranean regions) to document a compelling spatial and temporal relationship between the transition from collision to subduction, plate boundary curvature, and rapid tectonic block rotations. In some cases, these microplate rotations can initiate back-arc rifting. We also present numerical modelling results supporting our conceptual model for block rotations at collision/subduction transition. Our results suggest that the rate of microplate rotation depends on the incoming indentor velocity, and can be greatly enhanced by: (1) extensional stresses acting at the subduction interface (possibly due to slab roll back), and (2) a low-viscosity back-arc. Where viscosity of the back-arc is low, forearc microplate rotation dominates. In contrast, tectonic escape of strike-slip fault-bounded microplates is predicted in areas where the back-arc viscosity is high. Previous workers have suggested that the kinematics of the Anatolian block and back-arc rifting in the Aegean are influenced by some combination of forces associated with Arabia/Eurasia collision, and/or subduction (including slab rollback) at the Hellenic trench. Based on previous work from active western Pacific arcs, we propose that the collision of two separate indentors (Arabian promontory in the east, Apulian platform in the west), is a fundamental tectonic

  19. Crustal Deformation Field Around Rift Zone In Southeastern Afar Derived From Jers-1/in-sar (United States)

    Ozawa, T.; Nogi, Y.; Shibuya, K.

    Afar is one of the major active rift zones recognized on the ground and located around the triple junction of Arabia, Somalia and Nubian plates. Afar is one of the major rift zones recognized on the ground. The crustal deformation of Afar has been deduced from paleomagnetism, geology and seismology by many scientists. The current crustal deformation must be detected by geodetic measurements. Ruegg et al. (J. Geophys. Res., 1984) showed the crustal deformation across the Asal-Ghoubbet rift with rate of about 60 mm/yr extension derived from triangulation and trilateration. Walpersdorf et al. (J. Geodyn., 1999) show the opening between South Djibouti and Yemen with rate of 16 mm/yr by GPS surveys. Denser observations are required for detailed crustal deformation, however it is difficult to construct such observation network because of harsh environment. The geodetic application of remote sensing is useful in this region, and we apply JERS-1 SAR interferometry in southeastern Afar, which is one of the most active deformation area. In this study, we use six SAR scenes observed from 1996/5/20 to 1997/5/7, and generate five interferograms; these repeat cycles are 88 (2 pairs), 176, 264, 352 days. First, we generate the digital elevation model (DEM) from two 88 repeat cycle pairs applying the multiple pass SAR interferometry method by Kwok and Fahnestock (IEEE Trans. Geosci. Remote Sensing, 1996). Next, the topographic fringes of all pairs are removed using the DEM. The crustal deformation derived from SAR interferometry increases with expanding repeat cycle. Finally, the velocity field is estimated by fitting to linear trend for each pixel. The spreading rate of Asal-Ghoubbet rift derived from SAR interferometry is good agreement with that by Ruegg et al. (J. Geophys. Res., 1984). We can see the crustal deformation with the subsidence sense in the west of Asal-Ghoubbet rift. This suggests that the extension is distinguished in this area. The subsidence sense deformation

  20. Crustal and lithospheric structure of the west Antarctic Rift System from geophysical investigations: A review (United States)

    Behrendt, John C.


    The active West Antarctic Rift System, which extends from the continental shelf of the Ross Sea, beneath the Ross Ice Shelf and the West Antarctic Ice Sheet, is comparable in size to the Basin and Range in North America, or the East African rift systems. Geophysical surveys (primarily marine seismic and aeromagnetic combined with radar ice sounding) have extended the information provided by sparse geologic exposures and a few drill holes over the ice and sea covered area. Rift basins developed in the early Cretaceous accompanied by the major extension of the region. Tectonic activity has continued episodically in the Cenozoic to the present, including major uplift of the Transantarctic Mountains. The West Antarctic ice sheet, and the late Cenozoic volcanic activity in the West Antarctic Rift System, through which it flows, have been coeval since at least Miocene time. The rift is characterized by sparse exposures of late Cenozoic alkaline volcanic rocks extending from northern Victoria Land throughout Marie Byrd Land. The aeromagnetic interpretations indicate the presence of > 5 x 105 km2 (> 106 km3) of probable late Cenozoic volcanic rocks (and associated subvolcanic intrusions) in the West Antarctic rift. This great volume with such limited exposures is explained by glacial removal of the associated late Cenozoic volcanic edifices (probably hyaloclastite debris) concomitantly with their subglacial eruption. Large offset seismic investigations in the Ross Sea and on the Ross Ice Shelf indicate a ~ 17-24-km-thick, extended continental crust. Gravity data suggest that this extended crust of similar thickness probably underlies the Ross Ice Shelf and Byrd Subglacial Basin. Various authors have estimated maximum late Cretaceous-present crustal extension in the West Antarctic rift area from 255-350 km based on balancing crustal thickness. Plate reconstruction allowed crustal extension in late Cenozoic time is unlikely, alternate mechanisms have been proposed for the

  1. Exploring virtual reality technology and the Oculus Rift for the examination of digital pathology slides

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    Navid Farahani


    Full Text Available Background: Digital slides obtained from whole slide imaging (WSI platforms are typically viewed in two dimensions using desktop personal computer monitors or more recently on mobile devices. To the best of our knowledge, we are not aware of any studies viewing digital pathology slides in a virtual reality (VR environment. VR technology enables users to be artificially immersed in and interact with a computer-simulated world. Oculus Rift is among the world′s first consumer-targeted VR headsets, intended primarily for enhanced gaming. Our aim was to explore the use of the Oculus Rift for examining digital pathology slides in a VR environment. Methods: An Oculus Rift Development Kit 2 (DK2 was connected to a 64-bit computer running Virtual Desktop software. Glass slides from twenty randomly selected lymph node cases (ten with benign and ten malignant diagnoses were digitized using a WSI scanner. Three pathologists reviewed these digital slides on a 27-inch 5K display and with the Oculus Rift after a 2-week washout period. Recorded endpoints included concordance of final diagnoses and time required to examine slides. The pathologists also rated their ease of navigation, image quality, and diagnostic confidence for both modalities. Results: There was 90% diagnostic concordance when reviewing WSI using a 5K display and Oculus Rift. The time required to examine digital pathology slides on the 5K display averaged 39 s (range 10-120 s, compared to 62 s with the Oculus Rift (range 15-270 s. All pathologists confirmed that digital pathology slides were easily viewable in a VR environment. The ratings for image quality and diagnostic confidence were higher when using the 5K display. Conclusion: Using the Oculus Rift DK2 to view and navigate pathology whole slide images in a virtual environment is feasible for diagnostic purposes. However, image resolution using the Oculus Rift device was limited. Interactive VR technologies such as the Oculus Rift are

  2. Geometry and kinematics of the Triassic rift basin in Jameson Land (East Greenland) (United States)

    Guarnieri, Pierpaolo; Brethes, Anaïs.; Rasmussen, Thorkild M.


    The Triassic rift basin along the east Greenland margin described in this paper is represented by NE-SW trending basins and highs segmented by NW-SE trending transfer zones. Coarse-grained sediments along the eastern side of Jameson Land are shown to be hosted in half-graben structures belonging to the Carlsberg Fjord Basin that is bounded by NW dipping normal faults mapped and described after fieldwork in the Klitdal area in Liverpool Land. New aeromagnetic and electromagnetic data together with new drill cores allow the reinterpretation of available seismic lines showing the continuation of the Triassic rift basin toward the SW where it is buried under the Upper Triassic postrift sediments and the Jurassic successions of the Jameson Land Basin. The N-S trending Liverpool Land, interpreted as the boundary block of the Triassic basin, is shown to represent a structural high inherited from the Late Carboniferous tectonics and faulted during the Triassic rifting. The Carlsberg Fjord Basin and the Klitdal Fault System described in this paper should be seen as analogues to the Helgeland Basin in the Norwegian offshore that is bounded by the Ylvingen Fault Zone and to the Papa and West of Shetlands Basins that are bounded by the Spine Fault. The Triassic rift zone and transfer faults on both conjugate margins show a straightforward correlation with the trends of the initial spreading line and fracture zones of the northeast Atlantic indicating a possible inheritance of the Triassic rifting.

  3. Structural interpretation of El Hierro (Canary Islands) rifts system from gravity inversion modelling (United States)

    Sainz-Maza, S.; Montesinos, F. G.; Martí, J.; Arnoso, J.; Calvo, M.; Borreguero, A.


    Recent volcanism in El Hierro Island is mostly concentrated along three elongated and narrow zones which converge at the center of the island. These zones with extensive volcanism have been identified as rift zones. The presence of similar structures is common in many volcanic oceanic islands, so understanding their origin, dynamics and structure is important to conduct hazard assessment in such environments. There is still not consensus on the origin of the El Hierro rift zones, having been associated with mantle uplift or interpreted as resulting from gravitational spreading and flank instability. To further understand the internal structure and origin of the El Hierro rift systems, starting from the previous gravity studies, we developed a new 3D gravity inversion model for its shallower layers, gathering a detailed picture of this part of the island, which has permitted a new interpretation about these rifts. Previous models already identified a main central magma accumulation zone and several shallower high density bodies. The new model allows a better resolution of the pathways that connect both levels and the surface. Our results do not point to any correspondence between the upper parts of these pathways and the rift identified at the surface. Non-clear evidence of progression toward deeper parts into the volcanic system is shown, so we interpret them as very shallow structures, probably originated by local extensional stresses derived from gravitational loading and flank instability, which are used to facilitate the lateral transport of magma when it arrives close to the surface.

  4. Strain partitioning evolution and segmentation in hyperextended rift systems: insights from the Bay of Biscay and Pyrenees (United States)

    Tugend, Julie; Manatschal, Gianreto; Kusznir, Nick J.


    The understanding of the formation of hyper-extended domains has greatly benefited from combined studies at present-day and fossil rift systems preserved in collisional orogens. However, even though domains of extreme crustal and lithosphere thinning have been increasingly recognized, the spatial and temporal evolution of their tectonic processes remains poorly constrained. The Bay of Biscay and Pyrenees correspond to a Late Jurassic to Mid Cretaceous rift system including both oceanic and hyper-extended rift domains. The transition from preserved oceanic and rift domains to the West to their complete inversion in the East provide simultaneous access to seismically imaged and exposed parts of a hyper-extended rift system. We combine seismic interpretations and gravity inversion results with field mapping to identify and map former rift domains from the Bay of Biscay margins to their fossil analogues preserved in the Pyrenean orogen. This onshore/offshore map of the rift systems enables us to investigate the spatial and temporal evolution and the strain distribution related to the formation of a strongly segmented rift system preserved at the transition between the European and Iberian plate boundary. The restoration of the hyper-extended domains reveals the occurrence of spatially disconnected rift systems separated by weakly thinned continental ribbons (e.g. Landes High, Ebro block). While the offshore Bay of Biscay represent a former mature oceanic domain, the fossil remnants of hyper-extended domains preserved onshore in the Pyrenean-Cantabrian orogen record distributed extensional deformation partitioned between strongly segmented rift basins (e.g. Basque-Cantabrian, Arzacq-Mauléon basins). Rift system segmentation controls lateral variations of architecture and may be partly inherited from the pre-rift structuration. The relative timing of hyper-extensional processes is diachronous between the different rift systems recording the polyphased evolution of the

  5. Post Rift Evolution of the Indian Margin of Southern Africa (United States)

    Baby, Guillaume; Guillocheau, François; Robin, Cécile; Dall'asta, Massimo


    The objective of this study is to discuss the evolution of the South African Plateau along the Indian margin of Southern Africa. Since the classical works of A. du Toit and L.C. King and the improvement of thermochronological methods and numerical models, the question of the uplift of South African Plateau was highly debated with numerous scenarios: early Cretaceous at time of rifting (Van der Beek et al., J.Geophys.Res., 2002), late Cretaceous (Braun et al., Solid Earth, 2014), late Cenozoic (Burke & Gunnell, Geol.Soc.of America, 2008). Limited attention has been paid on the constraints provided by the offshore stratigraphic record of the surrounding margins. The objective of our study is to integrate onshore and offshore data (seismic profiles and industrial wells) to (1) analyse the infill of the whole margin (21°S to 31°S) from its hinterland to the distal deep water basin, (2) to constrain and quantify the vertical movements. We discuss the impact on accommodation and sediments partitioning, and their significance on South African Plateau uplift history. 1. Sedimentary basins of the Indian margin of Southern Africa are related to the break-up of Gondwana during late Jurassic, resulting in rifts and flexural basins. First marine incursions started during early Cretaceous times (oldest marine outcropping sediments are of Barremian age ~128 Ma). The region developed as a normal continental shelf at the Aptian-Albian transition (~113 Ma). 2. The Cretaceous geological history of the basins is characterized by differential uplift and subsidence of the basement, controlled by structures inherited from break up. As example, major early Cretaceous depocenters of the margin are located on the north of Save-Limpopo uplift (Forster, Paleogography, Paleoclimatology, Paleoecology, 1975) showing an eastward drainage pattern, maybe related to a proto Limpopo drainage. Those observations suggest that the escarpment bordering the Bushveld depression is an old relief inherited

  6. Innate Immune Response to Rift Valley Fever Virus in Goats (United States)

    Nfon, Charles K.; Marszal, Peter; Zhang, Shunzhen; Weingartl, Hana M.


    Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings. PMID:22545170

  7. Response to Rift Valley Fever in Tanzania: Challenges and Opportunities. (United States)

    Fyumagwa, Robert D; Ezekiel, Mangi J; Nyaki, Athanas; Mdaki, Maulid L; Katale, Zablon B; Moshiro, Candida; Keyyu, Julius D


    Rift Valley Fever (RVF) is an arthropod borne viral disease affecting livestock (cattle, sheep, goats and camels), wildlife and humans caused by Phlebovirus. The disease occurs in periodic cycles of 4-15 years associated with flooding from unusually high precipitations in many flood-prone habitats. Aedes and Culex spp and other mosquito species are important epidemic vectors. Because of poor living conditions and lack of knowledge on the pathogenesis of RVF, nomadic pastoralists and agro-pastoralists are at high risk of contracting the disease during epidemics. RVF is a professional hazard for health and livestock workers because of poor biosafety measures in routine activities including lack of proper Personal Protective Equipment (PPE). Direct exposure to infected animals can occur during handling and slaughter or through veterinary and obstetric procedures or handling of specimens in laboratory. The episodic nature of the disease creates special challenges for its mitigation and control and many of the epidemics happen when the governments are not prepared and have limited resource to contain the disease at source. Since its first description in 1930s Tanzania has recorded six epidemics, three of which were after independence in 1961. However, the 2007 epidemic was the most notable and wide spread with fatal human cases among pastoralists and agro-pastoralists concurrent with high livestock mortality. Given all the knowledge that exist on the epidemiology of the disease, still the 2006/2007 epidemic occurred when the government of Tanzania was not prepared to contain the disease at source. This paper reviews the epidemiology, reporting and outbreak-investigation, public awareness, preparedness plans and policy as well as challenges for its control in Tanzania.

  8. Rift Valley fever: Real or perceived threat for Zambia?

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    George Dautu


    Full Text Available Rift Valley fever (RVF in Zambia was first reported in 1974 during an epizootic of cattle and sheep that occurred in parts of Central, Southern and Copperbelt Provinces. In 1990, the disease was documented in nine districts of the provinces of Zambia. In the last two decades, there have been no reports of RVF. This long period without reported clinical disease raises questions as to whether RVF is a current or just a perceived threat. To address this question, World Organisation for Animal Health (OIE disease occurrence data on RVF for the period 2005−2010 in the Southern Africa Development Community (SADC was analysed. From the analysis, it was evident that most countries that share a common border with Zambia had reported at least one occurrence of the disease during the period under review. Due to the absence of natural physical barriers between Zambia and most of her neighbours, informal livestock trade and movements is a ubiquitous reality. Analysis of the rainfall patterns also showed that Zambia received rains sufficient to support a mosquito population large enough for high risk of RVF transmission. The evidence of disease occurrence in nearby countries coupled with animal movement, and environmental risk suggests that RVF is a serious threat to Zambia. In conclusion, the current occurrence of RVF in Zambia is unclear, but there are sufficient indications that the magnitude of the circulating infection is such that capacity building in disease surveillance and courses on recognition of the disease for field staff is recommended. Given the zoonotic potential of RVF, these measures are also a prerequisite for accurate assessment of the disease burden in humans.

  9. The 2007 Rift Valley Fever Outbreak in Sudan (United States)

    Hassan, Osama Ahmed; Ahlm, Clas; Sang, Rosemary; Evander, Magnus


    Rift Valley fever (RVF) is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus (RVFV) affecting humans and a wide range of animals. The virus is transmitted through bites from mosquitoes and exposure to viremic blood, body fluids, or tissues of infected animals. During 2007 a large RVF outbreak occurred in Sudan with a total of 747 confirmed human cases including 230 deaths (case fatality 30.8%); although it has been estimated 75,000 were infected. It was most severe in White Nile, El Gezira, and Sennar states near to the White Nile and the Blue Nile Rivers. Notably, RVF was not demonstrated in livestock until after the human cases appeared and unfortunately, there are no records or reports of the number of affected animals or deaths. Ideally, animals should serve as sentinels to prevent loss of human life, but the situation here was reversed. Animal contact seemed to be the most dominant risk factor followed by animal products and mosquito bites. The Sudan outbreak followed an unusually heavy rainfall in the country with severe flooding and previous studies on RVF in Sudan suggest that RVFV is endemic in parts of Sudan. An RVF outbreak results in human disease, but also large economic loss with an impact beyond the immediate influence on the directly affected agricultural producers. The outbreak emphasizes the need for collaboration between veterinary and health authorities, entomologists, environmental specialists, and biologists, as the best strategy towards the prevention and control of RVF. PMID:21980543

  10. Dendrochronological Investigations of Valonia Oak Trees in Western Greece

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    Andreas Papadopoulos


    Full Text Available Background and Purpose: Valonia oak (Quercus ithaburensis subsp. macrolepis (Kotschy Hedge & Yalt. is an east Mediterranean endemic, xerothermic and deciduous tree of particular interest in forestry. There has been a growing demand lately to include the species in reforestations in Greece which also increased the interest to investigate its response to climate change. The main purpose of this research is to study valonia oak from a dendrochronological – dendroclimatological point of view within its Mediterranean distribution range. Materials and Methods: Sampling took place in characteristic valonia oak stands where cross sections or tree-cores were taken from 40 trees. The cross sections and the tree-cores were prepared and cross-dated using standard dendrochronological methods and tree-ring widths were measured to the nearest 0.001 mm using the Windendro software program. The ARSTAN program was used to standardize the tree-ring data and to calculate dendrochronological statistical parameters. The inter-annual variability of tree-ring width and the radial growth trend were examined. Finally, tree-ring widths to climate relationships were calculated by orthogonal regression in combination with the bootstrap procedure using master residual chronology and monthly precipitation, temperature data and scPDSI drought index, from October of the n-1 year up to November of the n year. Results: The master chronology of valonia oak trees in Western Greece reaches 365 years, with an average ring width of 0.89 mm and with mean sensitivity being 0.21. The variation of the tree-ring widths indicates the influence of climate and human intervention in the past. Tree-ring to climate relationships show that valonia oak growth is positively affected by precipitations in January and March and by drought reduction during June and July. Conclusions: Valonia oak in Western Greece is a species of great interest for dendrochronological and dendroclimatological studies

  11. Two-Dimensional Numerical Modeling of Intracontinental Extension: A Case Study Of the Baikal Rift Formation

    DEFF Research Database (Denmark)

    Yang, H.; Chemia, Zurab; Artemieva, Irina

    The Baikal Rift zone (BRZ) is a narrow ( 10 km) active intra-continental basin, located at the boundary between the Amurian and Eurasian Plates. Although the BRZ is one of the major tectonically active rift zones in the world andit has been a subject of numerous geological...... and geophysical studies, the geodynamic origin and evolution of the BRZ is still debated. We applytwo-dimensional finite difference code to model the lithosphere-scale de-formation in several locations across the strike of the Baikal Rift zone. The model se-tup takes an advantage of regional geophysical models...... on topography,basin depth, the structure of the crust, lithosphere thickness, and the location of major tectonic faults. Our goal is to determine the physical models that reproduce reasonably well the ob-served deformation patterns of the BRZ.We perform a systematic analysis of the pa-rameter space in order...

  12. Tertiary rifting and its related structural development of the southern offshore Korea (United States)

    Sunwoo, Don


    Analysis of regional multi-channel seismic data integrated with exploratory wells has helped to investigate the structural and stratigraphic evolution of the southern offshore Korea. The northeast-southwest trending Taiwan Sinzi Fold Belt separates the area into two regions, the northern East China Sea Shelf Basin and the northern Okinawa Trough, with different structural features. The northern East China Sea Shelf Basin is characterized by Hupijiao Rise and Oligocene and late Miocene folded structures, whereas no uplifted and folded structures exist in the northern Okinawa Trough. However, the basement structure in both regions is much similar. The structure is characterized by a series of half-grabens and tilted fault blocks bounded by listric faults associated with rifting activity. These structures are more distinct in the northern Okinawa Trough. Rifting and extension in the northern East China Sea Shelf Basin, probably initiated in the Paleogene, resulted in a series of grabens and half-grabens. In the late Oligocene, the area west of the Hupijiao Rise experienced compressional tectonism and subsequent erosion flattened the area. In the early Miocene, extension and rifting resumed and the Hupijiao Rise uplifted locally. A second phase of compression, probably triggered by changes in plate motions caused large-scale uplift and folding in the eastern part of the area during the late Miocene. Subsequent erosion leveled the area including the Taiwan Sinzi Fold Belt, resulting in a significant regional unconformity. In contrast, the rifting and extension in the northern Okinawa Trough probably began in late Miocene and continued until early Pleistocene. The most active rifting occurred during early Pliocene and the rifting seems to become weaker during late Pliocene and early Pleistocene. The late Miocene unconformity that eroded the Taiwan Sinzi Fold Belt forms a conformable surface in the northern Okinawa Trough

  13. Very early rift sedimentation in the Turkana depression (EARS, Kenya): example of the Topernawi Formation (United States)

    Nutz, A.; Ragon, T.; Schuster, M.; Ghienne, J. F.


    Sedimentation associated with very early phase of continental rifting remains poorly understood as related deposits lie at deepest part of basins and rarely outcrop at the surface. However, understanding of these sediments are essential first to better-constrain early extensional phase and second in term of potential resources. The Turkana depression is a rift system active since the Paleogene, which makes the connection between Kenyan and Ethiopian domes. The southern area consists of four asymmetrical and juxtaposed grabens: the Lokichar, Turkwell, Kerio and South Lake Basin, which have been intensively documented through oil exploration. The northern part is structured into a single asymmetrical graben, the North Lake basin, less-known even oil exploration started. In this contribution, a sedimentary system preserved on the rift shoulder of the North Lake Basin is presented. Referred to as the Topernawi Fm, it is interpreted as recording the earliest phase of Cenozoic rifting in the area. The Topernawi Fm delineates a relic sedimentary basin of limited extension (3 - 5 km). Boundaries of the basin are inherited from basement structures, more precisely from the reactivation during Late Oligocene to Early Miocene of a previous transfer zone producing N40-50° border faults. Basin fills is up to 80 m thick and includes first alluvial fan associated with the reactivation of these faults and then braided fluvial deposits from axial system. Above, several volcanic events recurrently emplaced pyroclastic deposits, repeatedly reworked by fluvial channels. Subsequently, N-S trend faulting cut the Topernawi system during the development of the North Lake Basin and led to its partial preservation over the present-day rift shoulder. Geological maps, structural sections across Topernawi basin and sedimentary facies are presented. An integrated model is proposed to illustrate the basin evolution. Implications for rifting in Northern Turkana depression are discussed.

  14. Three-dimensional Aquila Rift: magnetized H I arch anchored by molecular complex (United States)

    Sofue, Yoshiaki; Nakanishi, Hiroyuki


    Three-dimensional structure of the Aquila Rift of magnetized neutral gas is investigated by analysing H I and CO line data. The projected distance on the Galactic plane of the H I arch of the Aquila Rift is r⊥ ˜ 250 pc from the Sun. The H I arch emerges at l ˜ 30°, reaches to altitudes as high as ˜500 pc above the plane at l ˜ 350°, and returns to the disc at l ˜ 270°. The extent of arch at positive latitudes is ˜1 kpc and the width is ˜100 pc. The eastern root is associated with the giant molecular cloud complex, which is the main body of the optically defined Aquila Rift. The H I and molecular masses of the Rift are estimated to be M_{H I}˜ 1.4{×} 10^5 M_{⊙} and M_H_2˜ 3{×} 10^5 M_{⊙}. Gravitational energies to lift the gases to their heights are E_{grav: H I}˜ 1.4{×} 10^{51} erg and E_{grav: H_2}˜ 0.3{×} 10^{51} erg, respectively. Magnetic field is aligned along the H I arch of the Rift, and the strength is measured to be B ˜ 10 μG using Faraday rotation measures of extragalactic radio sources. The magnetic energy is estimated to be Emag ˜ 1.2 × 1051 erg. A possible mechanism of formation of the Aquila Rift is proposed in terms of interstellar magnetic inflation by a sinusoidal Parker instability of wavelength of ˜2.5 kpc and amplitude ˜500 pc.

  15. Toward self-consistent tectono-magmatic numerical model of rift-to-ridge transition (United States)

    Gerya, Taras; Bercovici, David; Liao, Jie


    Natural data from modern and ancient lithospheric extension systems suggest three-dimensional (3D) character of deformation and complex relationship between magmatism and tectonics during the entire rift-to-ridge transition. Therefore, self-consistent high-resolution 3D magmatic-thermomechanical numerical approaches stand as a minimum complexity requirement for modeling and understanding of this transition. Here we present results from our new high-resolution 3D finite-difference marker-in-cell rift-to-ridge models, which account for magmatic accretion of the crust and use non-linear strain-weakened visco-plastic rheology of rocks that couples brittle/plastic failure and ductile damage caused by grain size reduction. Numerical experiments suggest that nucleation of rifting and ridge-transform patterns are decoupled in both space and time. At intermediate stages, two patterns can coexist and interact, which triggers development of detachment faults, failed rift arms, hyper-extended margins and oblique proto-transforms. En echelon rift patterns typically develop in the brittle upper-middle crust whereas proto-ridge and proto-transform structures nucleate in the lithospheric mantle. These deep proto-structures propagate upward, inter-connect and rotate toward a mature orthogonal ridge-transform patterns on the timescale of millions years during incipient thermal-magmatic accretion of the new oceanic-like lithosphere. Ductile damage of the extending lithospheric mantle caused by grain size reduction assisted by Zenner pinning plays critical role in rift-to-ridge transition by stabilizing detachment faults and transform structures. Numerical results compare well with observations from incipient spreading regions and passive continental margins.

  16. Coupled large earthquakes in the Baikal rift system: Response to bifurcations in nonlinear resonance hysteresis

    Directory of Open Access Journals (Sweden)

    Anatoly V. Klyuchevskii


    Full Text Available The current lithospheric geodynamics and tectonophysics in the Baikal rift are discussed in terms of a nonlinear oscillator with dissipation. The nonlinear oscillator model is applicable to the area because stress change shows up as quasi-periodic inharmonic oscillations at rifting attractor structures (RAS. The model is consistent with the space-time patterns of regional seismicity in which coupled large earthquakes, proximal in time but distant in space, may be a response to bifurcations in nonlinear resonance hysteresis in a system of three oscillators corresponding to the rifting attractors. The space-time distribution of coupled MLH > 5.5 events has been stable for the period of instrumental seismicity, with the largest events occurring in pairs, one shortly after another, on two ends of the rift system and with couples of smaller events in the central part of the rift. The event couples appear as peaks of earthquake ‘migration’ rate with an approximately decadal periodicity. Thus the energy accumulated at RAS is released in coupled large events by the mechanism of nonlinear oscillators with dissipation. The new knowledge, with special focus on space-time rifting attractors and bifurcations in a system of nonlinear resonance hysteresis, may be of theoretical and practical value for earthquake prediction issues. Extrapolation of the results into the nearest future indicates the probability of such a bifurcation in the region, i.e., there is growing risk of a pending M ≈ 7 coupled event to happen within a few years.

  17. Layered Crustal and Mantle Structure and Anisotropy beneath the Afar Depression and Malawi Rift Zone (United States)

    Reed, Cory Alexander

    Although a wealth of geophysical data sets have been acquired within the vicinity of continental rift zones, the mechanisms responsible for the breakup of stable continental lithosphere are ambiguous. Eastern Africa is host to the largest contemporary rift zone on Earth, and is thus the most prominent site with which to investigate the processes which govern the rupture of continental lithosphere. The studies herein represent teleseismic analyses of the velocity and thermomechanical structure of the crust and mantle beneath the Afar Depression and Malawi Rift Zone (MRZ) of the East African Rift System. Within the Afar Depression, the first densely-spaced receiver function investigation of crustal thickness and inferred velocity attenuation across the Tendaho Graben is conducted, and the largest to-date study of the topography of the mantle transition zone (MTZ) beneath NE Africa is provided, which reveals low upper-mantle velocities beneath the Afar concordant with a probable mantle plume traversing the MTZ beneath the western Ethiopian Plateau. In the vicinity of the MRZ, a data set comprised of 35 seismic stations is employed that was deployed over a two year period from mid-2012 to mid-2014, belonging to the SAFARI (Seismic Arrays For African Rift Initiation) experiment. Accordingly, the first MTZ topography and shear wave splitting analyses were conducted in the region. The latter reveals largely plate motion-parallel anisotropy that is locally modulated by lithospheric thickness abnormalities adjacent to the MRZ, while the former reveals normal MTZ thicknesses and shallow discontinuities that support the presence of a thick lithospheric keel within the MRZ region. These evidences strongly argue for the evolution of the MRZ via passive rifting mechanisms absent lower-mantle influences.

  18. [Medicine in the pre-hippocratic civilization of ancient greece]. (United States)

    Lips Castro, Walter; Urenda Arias, Catalina


    The beginnings of the magical-religious conception of disease would go back to before the development of writing (prehistory). During ancient times the world was conceived as a place where the supernatural was essential for mankind's survival, therefore, explanations of all phenomena, including disease, were based on supernatural causes. With the development of Greek civilization began the establishment of a rational approach to the nature of the world, which gradually included medicine. But the origin of the rational and naturalist perspective of medicine is due in part to the influence of ancient Egyptian civilization. Various terms were used to refer to healing agents at the pre-Hippocratic period of ancient Greece: iatromantis, phôlarcos, ouliads, and asclepiads. Later, in the ancient Greek civilization, healing through prophecy was gradually replaced, though not entirely displaced, by a new medicine, based on a rational theoretical framework about health and disease: téchnê iatrikê.

  19. Oil and Gas Emergency Policy: Greece 2010 update

    Energy Technology Data Exchange (ETDEWEB)



    This publication provides a detailed look at the specific systems in Greece for responding to an oil supply crisis. In 2007, the IEA published ''Oil Supply Security: Emergency Response of IEA Countries''. Rather than waiting for the completion of the current review cycle to renew this full publication, the IEA will provide updates to the country chapters as these become available following the specific country's review. The aim of series of publications is to provide an overview of the IEA oil emergency response system and a detailed look at the specific systems in each IEA country for responding to an oil supply crisis. The 2007 publication represented the findings of a five year review cycle of the emergency response mechanisms in IEA member countries. Since the 2007 publication, the IEA has started a new cycle of reviews which now includes reviewing gas emergency policies.

  20. Transdermal opioid patches for pain treatment in ancient Greece

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Hansen, Steen Honore'; Bartels, Else M.


    Pain treatment in ancient Greece, and through the middle ages in Europe, was to a great extent based on the expertise of the Greek physician Galen (c. 129-200 A.D.). Galen makes particular reference to "Olympic Victor's Dark Ointment" (OVDO), which is listed with a number of collyria. Galen states...... that OVDO can be useful for treating extreme pain and swellings, forming one of the best eye salves. Olympic Victor's Dark Ointment, an opium-based treatment, forms a "patch" when applied externally as an ointment, because it quickly dries to cover a localized region but still retains its elastic properties...... abilities in terms of drug delivery, which could be transferred to modern medicine. Indeed, this may lead to a better choice of morphine use and controlled management in individual patient cases, taking both pain relief and anti-inflammatory aspects into account....

  1. Juvenile (age 13-18) smoking incidence determinants in Greece. (United States)

    Vasilopoulos, Aristidis; Gourgoulianis, Konstantinos; Hatzoglou, Chryssi; Roupa, Zoe


    Smoking is a form of medical addiction, usually adopted during adolescence. The aim was to determine the prevalence of smoking in adolescents, aged 13-18 years old, to investigate their attitudes towards smoking and determine the contribution of social influences to onset and continuation of smoking. An anonymous self-report questionnaire was filled in by 873 high school students of Central Greece. Smoking incidence was 19.2%, with a 13.7% of regular smokers. The presence of a smoker in the family and a smoker friend were correlated with increased smoking rates. School grades were correlated negatively with smoking attitude and positively with allowance. Age was correlated negatively with social influence. Social influence appears stronger on younger ages and is a main determinant of smoking behavior. A more susceptible attitude towards smoking is formed during late adolescence. Certain social predictive factors for attitude towards smoking are proposed. © 2014 Wiley Publishing Asia Pty Ltd.

  2. Headache during airplane travel ("airplane headache"): first case in Greece. (United States)

    Kararizou, Evangelia; Anagnostou, Evangelos; Paraskevas, George P; Vassilopoulou, Sofia D; Naoumis, Dimitrios; Kararizos, Grigoris; Spengos, Konstantinos


    Headache related to airplane flights is rare. We describe a 37-year-old female patient with multiple intense, jabbing headache episodes over the last 3 years that occur exclusively during airplane flights. The pain manifests during take-off and landing, and is located always in the left retro-orbital and frontotemporal area. It is occasionally accompanied by dizziness, but no additional symptoms occur. Pain intensity diminishes and disappears after 15-20 min. Apart from occasional dizziness, no other symptoms occur. The patient has a history of tension-type headache and polycystic ovaries. Blood tests and imaging revealed no abnormalities. Here, we present the first case in Greece. We review the current literature on this rare syndrome and discuss on possible pathophysiology and the investigation of possible co-factors such as anxiety and depression.

  3. Exergy analysis of the energy use in Greece

    DEFF Research Database (Denmark)

    Koroneos, C.J.; Nanaki, E.A.; Xydis, George


    In this work, an analysis is being done on the concept of energy and exergy utilization and an application to the residential and industrial sector of Greece. The energy and exergy flows over the period from 1990 to 2004 were taken into consideration. This period was chosen based on the data...... reliability. The energy and exergy efficiencies are calculated for the residential and industrial sectors and compared to the findings of a previous study concerning the exergy efficiency of the Greek transport sector. The residential energy and exergy efficiencies for the year 2003 were 22.36% and 20.......92%, respectively, whereas the industrial energy and exergy efficiencies for the same year were 53.72% and 51.34%, respectively. The analysis of energy and exergy utilization determines the efficiency of the economy as a whole. The results can play an important role in the establishment of efficiency standards...

  4. Long survival in a 69,XXX triploid infant in Greece. (United States)

    Iliopoulos, Dimitrios; Vassiliou, Georgia; Sekerli, Eleni; Sidiropoulou, Vasiliki; Tsiga, Alexandra; Dimopoulou, Despina; Voyiatzis, Nikolaos


    The live birth of a triploidy infant is a very rare event and death usually occurs within the first hours of life. Triploid cases with a survival of more than two months are infrequent. We report on an infant with a 69,XXX chromosome constitution who survived 164 days. Chromosomal analysis demonstrated a 69,XXX karyotype with no evidence of mosaicism. This is the longest survival reported for this condition to date in Greece and the fourth longest worldwide. The infant was admitted to our clinic several times due to respiratory problems, and supplementary oxygen was required. The improved survival of our case was possibly due to better management of respiratory illness and prematurity, and these are essential factors that physicians should consider carefully with such rare cases.

  5. First results on video meteors from Crete, Greece (United States)

    Maravelias, G.


    This work presents the first systematic video meteor observations from a, forthcoming permanent, station in Crete, Greece, operating as the first official node within the International Meteor Organization's Video Network. It consists of a Watec 902 H2 Ultimate camera equipped with a Panasonic WV-LA1208 (focal length 12mm, f/0.8) lens running MetRec. The system operated for 42 nights during 2011 (August 19-December 30, 2011) recording 1905 meteors. It is significantly more performant than a previous system used by the author during the Perseids 2010 (DMK camera 21AF04.AS by The Imaging Source, CCTV lens of focal length 2.8 mm, UFO Capture v2.22), which operated for 17 nights (August 4-22, 2010) recording 32 meteors. Differences - according to the author's experience - between the two softwares (MetRec, UFO Capture) are discussed along with a small guide to video meteor hardware.

  6. Third Case of Streptococcus suis Infection in Greece

    Directory of Open Access Journals (Sweden)

    Marianneta Chatzopoulou


    Full Text Available Streptococcus suis is a facultative anaerobic, Gram-positive coccus that can cause severe disease to both pigs and humans. Its zoonotic potential was first recognized in 1968 when the first human case of meningitis was reported in Denmark. Since then, over 1600 human cases have been reported worldwide, the vast majority of which originated in Southeast Asia, and, thus, S. suis has been fairly characterized as an emerging pathogen. Infection in humans presents most commonly as bacteremia and/or meningitis while less common clinical manifestations such as endocarditis and septic arthritis can occur. S. suis infection is extremely uncommon in Greece and this is the third human case to be reported. Correct identification is of importance for optimization of antimicrobial treatment and epidemiological monitoring.

  7. Probabilistic seismic hazard assessment in Greece – Part 3: Deaggregation

    Directory of Open Access Journals (Sweden)

    G-A. Tselentis


    Full Text Available The present third part of the study, concerning the evaluation of earthquake hazard in Greece in terms of various ground motion parameters, deals with the deaggregation of the obtained results The seismic hazard maps presented for peak ground acceleration and spectral acceleration at 0.2 s and 1.0 s, with 10% probability of exceedance in 50 years, were deaggregated in order to quantify the dominant scenario. There are three basic components of each dominant scenario: earthquake magnitude (M, source-to-site distance (R and epsilon (ε. We present deaggregation maps of mean and mode values of M-R-ε triplet showing the contribution to hazard over a dense grid.

  8. Precursory seismicity pattern before strong earthquakes in Greece

    Directory of Open Access Journals (Sweden)

    Ioannis Baskoutas


    Full Text Available The temporal variation of seismicity, based on the retrospective analyses of three seismic parameters i.e., number of earthquakes, bvalue and energy released, have shown significant changes. Their remarkable relation with strong earthquakes occurrence was formulated as a qualitative character precursory seismicity pattern, which were interpreted in terms of a strong earthquakes occurrence preparation phases. The main characteristic of this pattern is that permits the identification of two period of low and high probability for an earthquake occurrence, suggesting its utility in the current seismic hazard assessment, by the continuous monitoring of the temporal variation of the seismic parameters in a given area. This paper investigates the qualitative and quantitative characteristics of the proposed precursory seismicity pattern, before al strong earthquakes occurrence in Greece the time period 2000-2008.

  9. Isolation of Mycobacterium malmoense in the island of Crete, Greece

    Directory of Open Access Journals (Sweden)

    Kourbeti I


    Full Text Available Mycobacterium malmoense was isolated from a broncho-alveolar lavage sample of a 73-year-old cancer (small cell lung carcinoma patient in Crete, representing the first reported case of this pathogen in Greece. The isolate was considered to be a colonizer and the patient did not receive any antimycobacterial treatment while he received chemotherapy to which he responded favourably. No signs of pulmonary infection were noted during the course of his disease. This case provides evidence of the ubiquitous nature of this mycobacterial species, believed until recently to favour cooler climates. We, therefore, propose that the index of suspicion for this pathogen should be raised particularly in patients with underlying immunodeficiency, cancer and chronic lung disease, irrespective of the geographic location.

  10. A fiducial reference site for satellite altimetry in Crete, Greece

    DEFF Research Database (Denmark)

    Mertikas, Stelios; Donlon, Craig; Mavrokordatos, Constantin

    With the advent of diverse satellite altimeters and variant measuring techniques, it has become mature in the scientific community, that an absolute reference Cal/Val site is regularly maintained to define, monitor, control the responses of any altimetric system. This work sets the ground...... for the establishment of a Fiducial Reference Site for ESA satellite altimetry in Gavdos and West Crete, Greece. It will consistently and reliably determine (a) absolute altimeter biases and their drifts; (b) relative bias among diverse missions; but also (c) continuously and independently connect different missions......, on a common and reliable reference and also to SI-traceable measurements. Results from this fiducial reference site will be based on historic Cal/Val site measurement records, and will be the yardstick for building up capacity for monitoring climate change. This will be achieved by defining and assessing any...

  11. The Architecture of Physical Culture in Ancient Greece

    Directory of Open Access Journals (Sweden)

    Leon Debevec


    Full Text Available The paper discusses the interaction between the culture of the body and architectural creativity in Ancient Greece. This interaction is rooted in a concern for personal and group security, the basis of which was physical fitness, as well as in the immersion of Greek reality in religion, which depicted gods and goddesses in perfect human bodies. Together with a developed feeling for the community, these two aspects stimulated the design of a special architecture devoted to physical culture. Baths, gymnasiums, palaestras, stadiums, hippodromes and theatres are original flashes of Greek architectural genius. They are golden ‘vessels’ devoted to the admiration of beauty, agility and the expressive power of the body – virtues which paved the way to a godlike semblance for every Greek.

  12. Reengineering NHS Hospitals in Greece: Redistribution Leads to Rational Mergers. (United States)

    Nikolentzos, Athanasios; Kontodimopoulos, Nick; Polyzos, Nikolaos; Thireos, Eleftherios; Tountas, Yannis


    The purpose of this study was to record and evaluate existing public hospital infrastructure of the National Health System (NHS), in terms of clinics and laboratories, as well as the healthcare workforce in each of these units and in every health region in Greece, in an attempt to optimize the allocation of these resources. An extensive analysis of raw data according to supply and performance indicators was performed to serve as a solid and objective scientific baseline for the proposed reengineering of the Greek public hospitals. Suggestions for "reshuffling" clinics and diagnostic laboratories, and their personnel, were made by using a best versus worst outcome indicator approach at a regional and national level. This study is expected to contribute to the academic debate about the gap between theory and evidence based decision-making in health policy.

  13. Physical abuse in the era of financial crisis in Greece. (United States)

    Kontos, Michael; Moris, Demetrios; Davakis, Spyridon; Schizas, Dimitrios; Pikoulis, Emmanouil; Liakakos, Theodoros


    Greece is suffering an economic recession of enormous magnitude, but whether its health has deteriorated as a result, has not yet been well established. We aim to present and analyze differences in demographics and clinical distribution of patients victims of physical abuse examined at the surgical emergency room in an Academic institution in the era of financial crisis. A retrospective database analysis of all patients that were examined to surgical emergency room (ER), between January 1st 2008 and December 31st 2014, was conducted. We only analyzed and evaluated data for the years 2008 to 2014. The number of patients being examined in the ER in 2011 was higher compared with that of 2014 and to 2008 respectively (Pcrisis. Financial crisis seems to have a multivariable effect on epidemiology and clinical diversity of the patients, victims of physical abuse, being examined in the ER.

  14. Evidence of recent plutonic magmatism beneath Northeast Peloponnesus (Greece) and its relationship to regional tectonics (United States)

    Tzanis, A.; Efstathiou, A.; Chailas, S.; Stamatakis, M.


    This work reports evidence of recent tectonically controlled plutonic magmatism related to Neogene volcanism in a broad area of Northeast Peloponnesus (Greece) that is straddled by the Hellenic Volcanic Arc and comprises the Argolid, the Argolic and Saronic gulfs and eastern Corinthia including the province of Crommyonia at the western half of Megaris peninsula (western Attica). We assess the contemporary stress field based on formal inversion of well-constrained crustal earthquake focal mechanisms and determine that it is principally extensional and NE-SW oriented, with σ1 strike and plunge being N64° and 77°, respectively and σ3 strikes and plunge N210° and 10°. This generates WNW-ESE and NW-SE faults, the former being dominant in the Saronic Gulf and the latter in the Argolic. In addition, the analysis predicts E-W and N330° faults with non-trivial right- and left-lateral heave, respectively, which are consistent with the R and R΄ directions of Riedel shear theory and explain a number of observed earthquake focal mechanisms and earthquake epicentre alignments. We also present a semi-quantitative analysis of observed aeromagnetic anomalies by performing numerical modelling of the radially averaged power spectrum with an efficient anomaly separation scheme based on a new type of 2-D Fourier domain filter introduced herein, the Radial Extended Meyer Window. This analysis identifies an extensive complex of magnetized rock formations buried at depths greater than 3 km which, given the geology and geotectonic setting of the area, can hardly be explained with anything other than calc-alkaline intrusions (plutons). At northeastern Corinthia and Crommyonia, this type of intrusive activity is unexceptional, mainly concentrated in the Gulf of Megara-Sousaki areas and consistent with the low-intensity, small-scale Pliocene dacitic volcanism observed therein. Conversely, large-scale elongate anomalies of E-W and N330° orientation have been identified in the Argolid

  15. Soils, slopes and source rocks: Application of a soil chemistry model to nutrient delivery to rift lakes (United States)

    Harris, Nicholas B.; Tucker, Gregory E.


    The topographic evolution of rift basins may be critical to the deposition of lacustrine source rocks such as the organic-rich Lower Cretaceous shales of the South Atlantic margin. Soils have been proposed as a key link between topography and source rock deposition by providing nutrients for the algae growth in rift lakes. Decreasing topographic relief from active rift to late rift has several effects on soils: soils become thicker and finer, erosion of dead surface and soil organic matter decreases, and the fractionation of precipitation between runoff and infiltration may favor increased infiltration. This hypothesis is tested by application of CENTURY, a complex box model that simulates transfer of nutrients within soil pools. The model is first applied to a rainforest soil, with several parameters individually varied. Infiltration experiments show that the concentrations of C, N and P in groundwater decrease rapidly as infiltration decreases, whether due to increased slope or to decreased precipitation. Increased erosion of surface plant litter and topsoil results in substantially decreased nutrient concentrations in groundwater. Increased sand content in soil causes an increase in nutrient concentration. We integrate these variables in analyzing topographic swathes from the Rio Grande Rift, comparing the southern part of the rift, where topography is relatively old and reduced, to the northern rift. C and P concentrations in groundwater increase as slope gradient decreases, resulting in substantially larger C and P concentrations in groundwater in the southern rift than the northern rift. Nitrogen concentrations in groundwater depends on whether infiltration varies as a function of slope gradient; in experiments where the fraction of infiltrated precipitation decreased with increasing slope, N concentrations was also substantially higher in the southern rift; but in experiments where that fraction was held constant, N concentrations was lower in the southern

  16. Presence of third molars in orthodontic patients from northern Greece

    Directory of Open Access Journals (Sweden)

    Barka G


    Full Text Available Georgia Barka,1 Georgios Tretiakov,1 Theodosios Theodosiou,2 Ioulia Ioannidou-Marathiotou31School of Dentistry, 2Biostatistics, Department of Informatics, School of Natural Sciences, 3Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, GreeceObjective: The purpose of the present study was to investigate the frequency of presence of third molar teeth and their distribution in each jaw and each side, according to sex, in a group of orthodontic patients with permanent dentition from northern Greece.Methods: The sample included panoramic radiographs from 220 patients with permanent dentition (mean age 13.62 ± 1.81. The Χ2 test was used to assess the relationships between the variables, and the Fisher's exact test was used in cases where the expected frequencies in each cell were <5.Results: The frequency of third molar presence was 79.1%, and 20.9% was the frequency of third molar agenesis. Intersexual differences in the number of third molars was not statistically significant. There was a correlation between the distribution of third molars on the right and the left side (Fisher's exact test = 100.788; P = 0. The two sides showed the same tendency toward the presence or absence of third molars. A correlation was also found between the distribution of maxillary and mandibular third molars (Fisher's exact test = 24.372; P = 0. In each jaw, the presence or absence of third molars was highly related to the number of third molars found in the other jaw.Conclusion: The present results showed that in this orthodontic group of northern Greek patients, presence accounted for 79.1% and agenesis for 20.9%. No significant difference was found between the frequencies of third molar presence on the left and right sides in either the maxilla or mandible.Keywords: third molars, presence, orthodontic population, Greeks

  17. Integrated flash flood vulnerability assessment: Insights from East Attica, Greece (United States)

    Karagiorgos, Konstantinos; Thaler, Thomas; Heiser, Micha; Hübl, Johannes; Fuchs, Sven


    In the framework of flood risk assessment, vulnerability is a key concept to assess the susceptibility of elements at risk. Besides the increasing amount of studies on flash floods available, in-depth information on vulnerability in Mediterranean countries was missing so far. Moreover, current approaches in vulnerability research are driven by a divide between social scientists who tend to view vulnerability as representing a set of socio-economic factors, and natural scientists who view vulnerability in terms of the degree of loss to an element at risk. Further, vulnerability studies in response to flash flood processes are rarely answered in the literature. In order to close this gap, this paper implemented an integrated vulnerability approach focusing on residential buildings exposed to flash floods in Greece. In general, both physical and social vulnerability was comparable low, which is interpreted as a result from (a) specific building regulations in Greece as well as general design principles leading to less structural susceptibility of elements at risk exposed, and (b) relatively low economic losses leading to less social vulnerability of citizens exposed. The population show high risk awareness and coping capacity to response to natural hazards event and in the same time the impact of the events are quite low, because of the already high use of local protection measures. The low vulnerability score for East Attica can be attributed especially to the low physical vulnerability and the moderate socio-economic well-being of the area. The consequence is to focus risk management strategies mainly in the reduction of the social vulnerability. By analysing both physical and social vulnerability an attempt was made to bridge the gap between scholars from sciences and humanities, and to integrate the results of the analysis into the broader vulnerability context.

  18. Health care practices in ancient Greece: The Hippocratic ideal. (United States)

    Kleisiaris, Christos F; Sfakianakis, Chrisanthos; Papathanasiou, Ioanna V


    Asclepius and Hippocrates focused medical practice on the natural approach and treatment of diseases, highlighting the importance of understanding the patient's health, independence of mind, and the need for harmony between the individual, social and natural environment, as reflected in the Hippocratic Oath. The aim of this study was to present the philosophy of care provision in ancient Greece and to highlight the influence of the Hippocratic ideal in modern health care practices. A literature review was carried out using browser methods in international databases. According to the literature, "healthy mind in a healthy body" was the main component of the Hippocratic philosophy. Three main categories were observed in the Hippocratic provision of care: health promotion, interventions on trauma care, and mental care and art therapy interventions. Health promotion included physical activity as an essential part of physical and mental health, and emphasized the importance of nutrition to improve performance in the Olympic Games. Interventions on trauma care included surgical practices developed by Hippocrates, mainly due to the frequent wars in ancient Greece. Mental care and art therapy interventions were in accordance with the first classification of mental disorders, which was proposed by Hippocrates. In this category music and drama were used as management tools in the treatment of illness and in the improvement of human behavior. The role of Asclepieion of Kos was highlighted which clearly indicates a holistic health care model in care provision. Finally, all practices regarded detailed recordings and evaluation of information within the guidelines. The Hippocratic philosophy on health care provision focused on the holistic health care model, applying standards and ethical rules that are still valid today.

  19. A climatological study of rural surface ozone in central Greece

    Directory of Open Access Journals (Sweden)

    P. D. Kalabokas


    Full Text Available Recent studies show that surface ozone levels at rural sites in Greece are generally high when compared with rural ozone measurements at northern European sites. The area of SE Europe, including Greece, is not very well monitored regarding rural ozone in comparison to central and northern Europe. In order to have the best possible picture of the rural surface ozone climatology in the area, based on the available data-sets of long-term continuous monitoring stations, the 10-year measurement records (1987-1996 of the Athens peripheral station of Liossia, (12 km N of the city center and the urban background station of Geoponiki (3 km W as well as the 4-year record (1996-1999 of the rural station of Aliartos (100 km NW of Athens, are analyzed in this paper. The data for Liossia and Geoponiki stations are screened for cases of strong airflow from rural areas (N-NE winds stronger than 5 m/s. The variation characteristics of the average rural ozone afternoon levels (12:00-18:00, with the best vertical atmospheric mixing, are mainly examined since these measurements are expected to be representative of the broader area. In all three stations there is a characteristic seasonal variation of rural ozone concentrations with lowest winter afternoon values at about 50 μg/m3 in December-January and average summer afternoon values at about 120 μg/m3 in July-August, indicating that high summer values are observed all over the area. The rural summer afternoon ozone values are very well correlated between the three stations, implying spatial homogeneity all over the area but also temporal homogeneity, since during the 13-year period 1987-1999 the rural afternoon ozone levels remained almost constant around the value of 120 μg/m3.

  20. Fluoride content of bottled waters available in Northern Greece. (United States)

    Ahiropoulos, V


    The aim of this study was to evaluate the fluoride content of bottled drinking waters commercially available in northern Greece and to report on the accuracy of the labelling of fluoride concentration. Twenty-two randomly selected commercial brands of bottled water were obtained from three supermarkets in Thessaloniki, Greece. Three bottles of each brand were purchased. Following calibration, six tests were conducted on each bottle using a combination fluoride-ion selective electrode (Orion, 96-09-00, MA, USA). The average reading for each brand was estimated and also compared with the fluoride content printed on the label. The mean (+/- SD) fluoride content of the bottled water samples was 0.35 (+/- 1.00) mg F/L with a range from 0.05 to 4.8 mg F/L. Only 18% (N = 4) of brands tested mention the fluoride concentration on the label, and 90% (N = 22) had a tested fluoride between 0.05 and 0.21 mg F/L. Of the remaining two brands, one was found to contain 0.3 mg F/L without having the fluoride concentration indicated on the label, and the other was labelled at 6 mg F/L, whereas the concentration was estimated as 4.8 mg F/L. The use of bottled water may be a significant source of systemic fluoride and therefore be considered as a risk factor for dental fluorosis in young children. This article shows that bottled drinking waters contain differing concentrations of fluoride. The manufacturers' labelling of fluoride concentrations may be inaccurate. When prescribing fluoride supplements, dentists should be aware of the fluoride content of bottled waters used by paediatric patients, especially brands with a concentration higher than 0.3 mg F/L. In view of the wide variation of fluoride concentration in the tested bottled waters, regulatory guidelines for controlling concentration in order to prevent dental fluorosis are recommended.

  1. Nurses perceptions about the nurse's social role in Greece

    Directory of Open Access Journals (Sweden)

    Lavdaniti M.


    Full Text Available B A C K G R O U N D : There is great evidence in nursing literature about the nurses’ perceptions on their role. Moststudies are focused on nursing practice and the actual role in hospitals, and other skills on basic-, intermediate- andadvanced- level patient care. In Greece, there are no studies examining the social role of nurses and nurses’ perceptionsabout it.A I M : Τo assess how nurses in Greece perceive their social role and investigate the factors influencing their social role.M A T E R I A L - M E T H O D : 342 nurses working in hospitals in the wider area of Thessaloniki were recruited inthis study. Data collection was carried out through one self-completed questionnaire developed by the researchers.R E S U L T S : 47.5% (n=162 agreed that society expects from nurses a particular behaviour, and almost half of theparticipants [51.8% (n=176] totally agreed that nurses are practicing a ‘litourgima’. 49.1% (n=165 agreed that nursesare health educators in society and another 46.3% (n=157 totally agreed that nurses undertake actions in order toeliminate patient discrimination. 47.6% (n=160 of the participants totally agreed that nurses should be dedicated toquality improvement and 40.9% of the sample (n=138 agreed that nurses should provide care during an epidemicwhile 41.3% totally agreed that nurses execute duties of other professionals. 45.7% (n=155 totally agreed that nursesshouldn’t deny care for patients with infectious diseases. A high percentage of nurses (60.1%, n=197 agreed that apart of the nursing role is patient advocacy.C O N C L U S I O N S : The findings of the present study indicate the importance of nurses’ social role, which mayallow them to empower patients to further recognize the role of nursing during hospitalization.

  2. The distribution of volcanism in the Beta-Atla-Themis region of Venus: Its relationship to rifting and implications for global tectonic regimes (United States)

    Airey, M. W.; Mather, T. A.; Pyle, D. M.; Ghail, R. C.


    A new analysis of the spatial relationships between volcanic features and rifts on Venus provides new constraints on models of planetary evolution. We developed a new database of volcanic features for the Beta-Atla-Themis (BAT) region and used nearest neighbor measurements to determine relationships between different types of volcanic features and the rifts. Nearest neighbor analysis shows that all the dome-type and corona-type subpopulations tend to cluster. Rift associations were inferred from the deviation of a feature's population distribution (as a function of distance from rift) from that of a random population. Dome-type features in general have no discernible relationship with rifts. Most corona-type features have a strong association with rifts, with intermediate and large volcanoes also tending to occur close to or on rifts. Shield fields, on the other hand, tend to occur away from rifts. Our new evidence supports classifications of rifts on Venus into different types, possibly by age, with a shift from globally dispersed (more uniform) volcanism toward the more rift-focused distribution, which suggests a shift in tectonic regime. Our observations are consistent with recent models proposing the evolution of Venus from a stagnant lid regime to a subcrustal spreading regime. We also present evidence for a failed rift on Venus and note that this process may be analogous, albeit on a larger scale, to a proposed model for the evolution of the East African rift system.

  3. Comparison of hydrothermal activity between the Adriatic and the Red Sea rift margins (United States)

    Ball, Philip; Incerpi, Nicolò; Birkle, Peter; Lacsamana, Elizabeth; Manatschal, Gianreto; Agar, Susan; Zhang, Shuo; Borsato, Ron


    Detailed field studies, and access to high-quality seismic reflection and refraction data have led to an improved understanding of the architecture and evolution of magma poor and magma rich margins. Associated with the spatial-temporal evolution of the rift, it is evident that there are evolving, extensive, fluid-rock interactions due to the infiltration of fluids within the sediment, basement and lithospheric mantle. Key questions therefore arise: What are the different fluid-rock reactions that can be typed to different geodynamic stages of the rift evolution? What are their compositions and how do they interact with their environment (basement, sediments, evaporites, hydrosphere, and magmatism)? What are the implications for the evolution of the margin rheology, thermal structure, depositional environments/organic matter maturity, and reservoir quality? The Adriatic paleo-rifted margin is preserved in both SE Switzerland and northern Italy. The field exposures provide a unique opportunity to study the fluid flow history of a hyperextended magma poor extensional margin. Analysis of breccias, cement veins and replacement minerals reveal that the margin records a complex, long-lasting history of dolomitization, calcification and silicification during the Jurassic rifting. The Red Sea by contrast is a young rifted margin. It differs from the paleo-Adriatic margin by several characteristics: volcanism is more evident, and syn-tectonic sediments, including evaporites (halite and anhydrite) are thicker. Several core and fluid samples are available from both onshore and offshore wells, which reveal rift-related hydrothermal alteration. In addition, we find evidence for the presence of an extreme dynamic hydraulic system with infiltration of surface water into sub-salt units during Late Pleistocene. In this study we present results from petrographic and geochemical analysis of basement and sedimentary rocks from Adriatic field-derived samples and core/subsurface fluid

  4. Historical volcanism and the state of stress in the East African Rift System

    Directory of Open Access Journals (Sweden)

    Geoffrey Wadge


    Full Text Available Crustal extension at the East African Rift System (EARS should, as a tectonic ideal, involve a stress field in which the direction of minimum horizontal stress is perpendicular to the rift. A volcano in such a setting should produce dykes and fissures parallel to the rift. How closely do the volcanoes of the EARS follow this? We answer this question by studying the 21 volcanoes that have erupted historically (since about 1800 and find that 7 match the (approximate geometrical ideal. At the other 14 volcanoes the orientation of the eruptive fissures/dykes and/or the axes of the host rift segments are oblique to the ideal values. To explain the eruptions at these volcanoes we invoke local (non-plate tectonic variations of the stress field caused by: crustal heterogeneities and anisotropies (dominated by NW structures in the Protoerozoic basement, transfer zone tectonics at the ends of offset rift segments, gravitational loading by the volcanic edifice (typically those with 1-2 km relief and magmatic pressure in central reservoirs. We find that the more oblique volcanoes tend to have large edifices, large eruptive volumes and evolved and mixed magmas capable of explosive behaviour. Nine of the volcanoes have calderas of varying ellipticity, 6 of which are large, reservoir-collapse types mainly elongated across rift (e.g. Kone and 3 are smaller, elongated parallel to the rift and contain active lava lakes (e.g. Erta Ale, suggesting different mechanisms of formation and stress fields. Nyamuragira is the only EARS volcano with enough sufficiently well-documented eruptions to infer its long-term dynamic behaviour. Eruptions within 7 km of the volcano are of relatively short duration (<100 days, but eruptions with more distal fissures tend to have greater obliquity and longer durations, indicating a changing stress field away from the volcano. There were major changes in long-term magma extrusion rates in 1977 (and perhaps in 2002 due to major along-rift

  5. Force Required to Breakup a Continent: Implications on Rifting Localization and Migration (United States)

    Svartman Dias, A. E.; Lavier, L. L.; Hayman, N. W.


    The maximum force from ridge push available is about 5 TN/m, lower than that required by 2D and 3D numerical experiments to rift the lithosphere in the absence of magmatic input. We carry out 2D numerical experiments without any magmatic input to study the extensional force necessary to start a rift basin and to breakup a continent. We assume a range of initial temperature structure, crust and mantle initial thicknesses and composition. In a first step, we use velocity boundary conditions (1cm/yr) and we monitor the force necessary to breakup the continent. Results can be classified in two groups according to the amount of force needed to rift through time: (1) The initial force builds up rapidly to 12-20 TN/m within 0.4-1.0 Myr. This is followed by an exponential decrease due to early strain localization and lithospheric weakening. The force is value of 3-5 TN/m from 0.4 Myr to 10 Myr, when strain starts localizing. The constant force through time reflects lithosphere strengthening and migration of the deformation. This rift migration forms a wide basin (> 250 km wide) that may evolve to form very asymmetric conjugate margins. Breakup occurs 18 Myr after the onset of rifting or later. This second group corresponds to experiments with initial Tmoho > 650 km and crustal thicknesses ≥ 35 km. High bending stresses result in upper crust brittle failure and on enhancement of lower crust lateral flow. Interaction between ductile failure in the lower crust and brittle failure in the upper crust controls the migration of the deformation. In a second step, we repeat the same experiments applying a constant extensional force ≤ 5 TN/m to test whether and how the limited ridge push force naturally available can rift and breakup a continent. We then compare our results to the evolution of aborted rifts and to along strike variations in rifted magins such as the South Atlantic.

  6. The major tectonic boundaries of the Northern Red Sea rift, Egypt derived from geophysical data analysis (United States)

    Saleh, Salah; Pamukçu, Oya; Brimich, Ladislav


    In the present study, we have attempted to map the plate boundary between Arabia and Africa at the Northern Red Sea rift region including the Suez rift, Gulf of Aqaba-Dead Sea transform and southeastern Mediterranean region by using gravity data analysis. In the boundary analysis method which was used; low-pass filtered gravity anomalies of the Northern Red Sea rift region were computed. Different crustal types and thicknesses, sediment thicknesses and different heat flow anomalies were evaluated. According to the results, there are six subzones (crustal blocks) separated from each other by tectonic plate boundaries and/or lineaments. It seems that these tectonic boundaries reveal complex structural lineaments, which are mostly influenced by a predominant set of NNW-SSE to NW-SE trending lineaments bordering the Red Sea and Suez rift regions. On the other side, the E-W and N-S to NNE-SSW trended lineaments bordering the South-eastern Mediterranean, Northern Sinai and Aqaba-Dead Sea transform regions, respectively. The analysis of the low pass filtered Bouguer anomaly maps reveals that the positive regional anomaly over both the Red Sea rift and South-eastern Mediterranean basin subzones are considered to be caused by the high density of the oceanic crust and/or the anomalous upper mantle structures beneath these regions whereas, the broad medium anomalies along the western half of Central Sinai with the Suez rift and the Eastern Desert subzones are attributed to low-density sediments of the Suez rift and/or the thick upper continental crustal thickness below these zones. There are observable negative anomalies over the Northern Arabia subzone, particularly in the areas covered by Cenozoic volcanics. These negative anomalies may be attributed to both the low densities of the surface volcanics and/or to a very thick upper continental crust. On the contrary, the negative anomaly which belongs to the Gulf of Aqaba-Dead Sea transform zone is due to crustal thickening

  7. Kinematics of the Ethiopian Rift and Absolute motion of Africa and Somalia Plates (United States)

    Muluneh, A. A.; Cuffaro, M.; Doglioni, C.


    The Ethiopian Rift (ER), in the northern part of East African Rift System (EARS), forms a boundary zone accommodating differential motion between Africa and Somalia Plates. Its orientation was influenced by the inherited Pan-African collisional system and related lithospheric fabric. We present the kinematics of ER derived from compilation of geodetic velocities, focal mechanism inversions, structural data analysis, and construction of geological profiles. GPS velocity field shows a systematic eastward magnitude increase in NE direction in the central ER. In the same region, incremental extensional strain axes recorded by earthquake focal mechanism and fault slip inversion show ≈N1000E orientation. This deviation between GPS velocity trajectories and orientation of incremental extensional strain is developed due to left lateral transtensional deformation. This interpretation is consistent with the en-échelon pattern of tensional and transtensional faults, the distribution of the volcanic centers, and the asymmetry of the rift itself. Small amount of vertical axis blocks rotation, sinistral strike slip faults and dyke intrusions in the rift accommodate the transtensional deformation. We analyzed the kinematics of ER relative to Deep and Shallow Hot Spot Reference Frames (HSRF). Comparison between the two reference frames shows different kinematics in ER and also Africa and Somalia plate motion both in magnitude and direction. Plate spreading direction in shallow HSRF (i.e. the source of the plumes locates in the asthenosphere) and the trend of ER deviate by about 27°. Shearing and extension across the plate boundary zone contribute both to the style of deformation and overall kinematics in the rift. We conclude that the observed long wavelength kinematics and tectonics are consequences of faster SW ward motion of Africa than Somalia in the shallow HSRF. This reference frame seems more consistent with the geophysical and geological constraints in the Rift. The

  8. How inheritance, geochemical and geophysical properties of the lithospheric mantle influence rift development and subsequent collision (United States)

    Picazo, Suzanne; Chenin, Pauline; Müntener, Othmar; Manatschal, Gianreto; Karner, Garry; Johnson, Christopher


    In magma-poor rifted margins, the rift structures, width of necking zones and overall geometry are controlled by the heterogeneities of geochemical and geophysical properties of the crust and mantle. In this presentation we focus on the mantle heterogeneities and their major implications on the closure of a hyper-extended rifted system. In our study, we review the clinopyroxene and spinel major element composition from the Liguria-Piemonte domain, the Pyrenean domain, the Dinarides and Hellenides ophiolites and the Iberia-Newfoundland rifted margins (Picazo et al, 2016). It would seem that during an extensional cycle i.e., from post-orogenic collapse to polyphase rifting to seafloor spreading, the mineral compositions of mantle peridotites are systematically modified. The initially heterogeneous subcontinental mantle cpx (inherited mantle type 1) equilibrated in the spinel peridotite field and is too enriched in Na2O and Al2O3 to be a residue of syn-rift melting. The heterogeneous inherited subcontinental mantle becomes progressively homogenized due to impregnation by MORB-type melts (refertilized mantle-type 2) during extensional thinning of the lithosphere. At this stage, cpx equilibrate with plagioclase and display lower Na2O and Al2O3 and high Cr2O3 contents. The system might evolve into breakup and oceanization (mantle type 3) i.e., self-sustained steady-state seafloor spreading. The different mantle-types are present in various reconstructed sections of magma-poor margins and display a systematic spatial distribution from mantle type 1 to 3 going oceanwards in Western and Central Europe. We estimated the density of the three identified mantle types using idealized modal peridotite compositions using the algorithm by Hacker et al, (2003). The density of the refertilized plagioclase peridotite is predicted to be lower than that of inherited subcontinental and depleted oceanic mantle. This has some interesting consequences on the reactivation of rifted margins

  9. Lithological Influences on Occurrence of High-Fluoride Waters in The Central Kenya Rift (United States)

    Olaka, L. A.; Musolff, A.; Mulch, A.; Olago, D.; Odada, E. O.


    Within the East African rift, groundwater recharge results from the complex interplay of geology, land cover, geomorphology, climate and on going volcano-tectonic processes across a broad range of spatial and temporal scales. The interrelationships between these factors create complex patterns of water availability, reliability and quality. The hydrochemical evolution of the waters is further complex due to the different climatic regimes and geothermal processes going on in this area. High fluoridic waters within the rift have been reported by few studies, while dental fluorosis is high among the inhabitants of the rift. The natural sources of fluoride in waters can be from weathering of fluorine bearing minerals in rocks, volcanic or fumarolic activities. Fluoride concentration in water depends on a number of factors including pH, temperature, time of water-rock formation contact and geochemical processes. Knowledge of the sources and dispersion of fluoride in both surface and groundwaters within the central Kenya rift and seasonal variations between wet and dry seasons is still poor. The Central Kenya rift is marked by active tectonics, volcanic activity and fumarolic activity, the rocks are majorly volcanics: rhyolites, tuffs, basalts, phonolites, ashes and agglomerates some are highly fractured. Major NW-SE faults bound the rift escarpment while the rift floor is marked by N-S striking faults We combine petrographic, hydrochemistry and structural information to determine the sources and enrichment pathways of high fluoridic waters within the Naivasha catchment. A total of 120 water samples for both the dry season (January-February2012) and after wet season (June-July 2013) from springs, rivers, lakes, hand dug wells, fumaroles and boreholes within the Naivasha catchment are collected and analysed for fluoride, physicochemical parameters and stable isotopes (δ2 H, δ18 O) in order to determine the origin and evolution of the waters. Additionally, 30 soil and

  10. Blood Glucose and Cholesterol Concentrations in a Mediterranean Rural Population of Andros Island, Greece

    Directory of Open Access Journals (Sweden)

    Konstantinos T Tsaousis


    Conclusions: The present study confirms that dyslipidemia and high blood glucose levels are prevalent among the rural populations of Greece and therefore informative campaigns and structured screening programs are required to promote preventive health care.

  11. The Body as a Form of ID and Social Differentiation (In Ancient Greece)

    National Research Council Canada - National Science Library

    Sahaj, Tomasz


    .... In ancient Greece, the corporeal nature of man was a category strongly linked with a precisely understood form physical culture, including both philosophy and medicine and what we would call today ‘physiotherapy...

  12. Balancing a cline by influx of migrants: a genetic transition in water frogs of eastern Greece

    National Research Council Canada - National Science Library

    Hotz, Hansjürg; Beerli, Peter; Uzzell, Thomas; Guex, Gaston-Denis; Pruvost, Nicolas B M; Schreiber, Robert; Plötner, Jörg


    Variation patterns of allozymes and of ND3 haplotypes of mitochondrial DNA reveal a zone of genetic transition among western Palearctic water frogs extending across northeastern Greece and European Turkey...

  13. Organic geochemistry of Amynteo lignite deposit, northern Greece: a Multi-analytical approach

    NARCIS (Netherlands)

    Iordanidis, A.; Schwarzbauer, J.; Georgakopoulos, A.; Lagen, van B.


    Several lignite samples were collected from boreholes of the Amynteo opencast lignite mine, northern Greece. Organic geochemical characteristics were investigated with the help of various analytical techniques, comprising Gas Chromatography (GC) and Gas-chromatography-Mass Spectrometry (GC-MS),

  14. The accomondation hypothesis in Greece: a tri-variate granger-causality aproach


    Καρασαβόγλου, Αναστάσιος; Κατρακιλίδης, Κωνσταντίνος


    This paper with title "The Accommodation Hypothesis in Greece. A tri-variate Granger-Causality Approach" investigates empirically the causal relationship between money growth, budget deficits and inflation in Greece employing a tri-variate error-correction model. The causal relationship between money, deficits and inflation is explored using three alternative definitions for money: high-powered, M l and M2 definitions of money stock. The results support the accommodation hypothesi...

  15. [Medical mission of Louis-André Gosse during his trip to Greece (1827-1829)]. (United States)

    Bouvier-Bron, M


    Louis-André Gosse (1791-1873), a liberal-minded Geneva physician, went to Greece in 1827 in order to work, for a couple of years, for the Greek State, which had won its independence just a few years ago. When, in 1828, an Egyptian army brought plague back to Greece, Gosse took an active part in the fight against the epidemic. The present author gives a detailed account of Gosse's relation of his experience including treatment and preventive measures.

  16. Smoke-free hospitals in Greece: Personnel perceptions, compliance and smoking habit

    Directory of Open Access Journals (Sweden)

    Tzilepi Penelope


    Full Text Available Abstract Smoke-free environments in Greece are scarce. Despite existent legislation that forbids smoking in all health care service centers, smoking is still evident. Using a random sample of hospital personnel from a large university hospital in Greece, we evaluated their smoking habits, perceptions and compliance towards hospital smoking regulations. 57.8% of the nursing personnel and 34.5% of medical/research staff were found to be current smokers (p

  17. Rift Valley fever: current challenges and future prospects

    Directory of Open Access Journals (Sweden)

    Himeidan YE


    Full Text Available Yousif E Himeidan Vector Control Unit, Africa Technical Research Centre, Vector Health International, Arusha, Tanzania Abstract: Rift Valley fever (RVF is a zoonotic, mosquito-borne viral disease that affects human health and causes significant losses in the livestock industry. Recent outbreaks have led to severe human infections with high mortality rates. There are many challenges to applying effective preventive and control measures, including weak infrastructure of health facilities, lack of capacity and support systems for field logistics and communication, access to global expert organizations, and insufficient information on the epidemiological and reservoir status of the RVF virus. The health systems in East African countries are underdeveloped, with gaps in adaptability to new, more accurate and rapid techniques, and well-trained staff that affect their capacity to monitor and evaluate the disease. Surveillance and response systems are inadequate in providing accurate information in a timely manner for decision making to deal with the scope of interrupting the disease transmission by applying mass animal vaccination, and other preventive measures at the early stage of an outbreak. The historical vaccines are unsuitable for use in newborn and gestating livestock, and the recent ones require a booster and annual revaccination. Future live-attenuated RVF vaccines should possess lower safety concerns regardless of the physiologic state of the animal, and provide rapid and long-term immunity after a single dose of vaccination. In the absence of an effective vaccination program, prevention and control measures must be immediately undertaken after an alert is generated. These measures include enforcing and adapting standard protocols for animal trade and movement, extensive vector control, safe disposal of infected animals, and modification of human–animal contact behavior. Directing control efforts on farmers and workers who deal with

  18. The genesis of the Nissi peatland (northwestern Greece) as an example of peat and lignite deposit formation in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Christianis, K. (University of Patras, Patras (Greece). Dept of Geology)


    The Nissi Fen is located in a 12 km[sup 2] intramontane basin in northwestern Greece. Since the last glacial, limnotelmatic and pure telmatic conditions, controlled mainly by karstic springs and partly by surface waters, favoured peat formation in the basin, resulting in the accumulation of a peat deposit up to 15 m thick. The present fen occupies a large area of almost 9 km[sup 2]. Flora cover comprises mainly Cyperaceae ([ital Cladium mariscus] and [ital Carex] species), while [ital Phragmites australis] extend along the banks of a river flowing through the basin, as well as around a lake in the southern part of the fen. These species also contributed to the peat formation. The Nissi peatland shows many genetic similarities to the Philippi peat deposit, Eastern Macedonia, and may be considered as a recent analogue to the lignite deposits in the basins of Ptolemais, Western Macedonia and Megalopolis, the Peloponnese. 36 refs., 5 figs.

  19. Middle to late cenozoic magmatism of the southeastern Colorado plateau and central Rio Grande rift (New Mexico and Arizona, U.S.A.) : a model for continental rifting (United States)

    Baldridge, W.S.; Perry, F.V.; Vaniman, D.T.; Nealey, L.D.; Leavy, B.D.; Laughlin, A.W.; Kyle, P.; Bartov, Y.; Steinitz, G.; Gladney, E.S.


    The region of the present Rio Grande rift and southeastern Colorado Plateau underwent lithospheric extension during middle to late Cenozoic deformation affecting the entire southwestern U.S. Lithospheric mantle was disrupted, and in many regions displaced or replaced by asthenospheric mantle at depths from which basaltic magmas were derived and erupted to the surface. Study of the igneous rocks erupted or intruded during this deformation yields insights into processes of magmatism associated with extension of continental lithosphere. Magmatic rocks associated with an early (late Oligocene-early Miocene) ductile phase of extension are dominantly basaltic andesites and related, calc-alkaline intermediate to silicic derivative rocks. Mafic magmas were probably derived from isotopically "enriched" lithospheric mantle. Igneous rocks associated with a later (middle Miocene-Holocene), more brittle phase of extension include widespread basaltic rocks and localized central volcanoes of intermediate to silicic composition. Isotopic compositions of mafic rocks, which include both tholeiitic and alkalic basalts, correlate strongly with tectonic setting and lithospheric structure. Basalts erupted in areas of greatest crustal extension, such as the central and southern rift and Basin and Range province, were derived from isotopically "depleted" (correlated with "asthenospheric") mantle. Also, isotopic compositions of Pliocene to Holocene basalts are slightly more depleted than those of Miocene basalts, suggesting that subcrustal lithospheric mantle was thinned during late Miocene extension. Intermediate rocks of the central volcanoes formed by a complex combination of processes, probably dominated by fractional crystallization and by assimilation of upper and lower crust in isolated, small magma chambers. The petrologic, geochemical, and isotopic data are compatible with a model, derived first from geophysical data, whereby lithosphere is thinned beneath the central rift and

  20. Health, economic crisis, and austerity: A comparison of Greece, Finland and Iceland. (United States)

    Tapia Granados, José A; Rodriguez, Javier M


    Reports have attributed a public health tragedy in Greece to the Great Recession and the subsequent application of austerity programs. It is also claimed that the comparison of Greece with Iceland and Finland-where austerity policies were not applied-reveals the harmful effect of austerity on health and that by protecting spending in health and social budgets, governments can offset the harmful effects of economic crises on health. We use data on life expectancy, mortality rates, incidence of infectious diseases, rates of vaccination, self-reported health and other measures to examine the evolution of population health and health services performance in Greece, Finland and Iceland since 1990-2011 or 2012-the most recent years for which data are available. We find that in the three countries most indicators of population health continued improving after the Great Recession started. In terms of population health and performance of the health care system, in the period after 2007 for which data are available, Greece did as good as Iceland and Finland. The evidence does not support the claim that there is a health crisis in Greece. On the basis of the extant evidence, claims of a public health tragedy in Greece seem overly exaggerated. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Seismic stratigraphy of rift basins: techniques, methods and its application in the Reconcavo Basin; Sismoestratigrafia de bacias rifte: tecnicas, metodos e sua aplicacao na Bacia do Reconcavo

    Energy Technology Data Exchange (ETDEWEB)

    Kuchle, Juliano [Universidade Federal do Rio Grande do Sul (UFRGS). Inst. de Geociencias. Programa de Pos-Graduacao em Geociencias (Brazil)], e-mail:; Scherer, Claiton Marlon dos Santos [Universidade Federal do Rio Grande do Sul (UFRGS). Inst. de Geociencias. Dept. de Paleontologia e Estratigrafia (Brazil)], e-mail:


    This paper aims a proposal of interpretation and seismic stratigraphy systematic mapping of rift basins based on genetic concepts, as offered by the basic development of the Sequence Stratigraphy - the temporal interpretation of units based on concepts derived from variables and observable in depositional trends. So, rift basins are controlled by specifically variables and its relationships, which results in theoretical evolutional models. Those theoretical models are detailed as depositional trends denominated stacking patterns. Thus, from the stacking patterns, it is able to establish the inverse way analysis, picturing evolutional models and controlling variables. The main objective of this paper is the migration of the genetic tectonic-stratigraphic model of rift basins to the seismic platform, supported by the key-concepts of the seismic stratigraphy. This analysis is based on the recognition of seismic stratigraphic units which composes the tectonic system tracts - basic units of the framework, and these system tracts are formed by specific stacking patterns for each portion of the half Graben. As those stacking patterns reflect changes in the accommodation, stratigraphic surfaces and strata termination patterns are established. Therefore, a whole conceptual basis of seismic stratigraphy recognition and mapping is proposed, as well as a time determination of evolutional models in chronostratigraphic diagrams (Wheeler charts), to supply a useful tectonic-stratigraphic framework to hydrocarbon exploration. (author)

  2. Shoot and root growth of cereals under reduced tillage in Organic Farming in field trials in Germany and Greece


    Vakali, Christina


    In two organically cultivated field trials, located in Germany and Greece, effects of reduced primary tillage systems on root and shoot growth of cereals were investigated. The field trial in Rommersheim near Mainz, Germany, was established in 1994. A similar experiment was established in 1995 located in Athens, Greece. Mouldboard plough, two-layer plough and layer cultivator were used in Germany. Mouldboard plough, rotary hoe and zero tillage were applied in Greece. The field experiment in G...

  3. From an ocean floor wrench zone origin to transpressional tectonic emplacement of the Sithonia ophiolite, eastern Vardar Suture Zone, northern Greece (United States)

    Bonev, Nikolay; Filipov, Petyo


    In the Hellenides of northern Greece, the Sithonia back-arc ophiolite constitute an element of the Vardar suture zone against the Chortiatis island arc magmatic suite, the Melissochori Formation and the Serbo-Macedonian Massif further north at the Mesozoic continental margin of Eurasia. A granodiorite from the Chortiatis island arc magmatic suite crystallized at 160 Ma as derived from new U-Pb zircon geochronology and confirms the end of arc magmatic activity that started at around 173 Ma. Located southerly of the Chortiatis island arc magmatic suite, the Sithonia ophiolite had igneous life from 159 to 149 Ma, and the ophiolite interfinger with clastic-carbonate Kimmeridgian sediments. Magmatic structures (i.e., sheeted dykes) in the ophiolite witness for NE-trending rift axis, while the transform faults and fracture zones sketch NW-SE transcurrent transtension-like propagation of the rift-spreading center at Sithonia that is consistent with a dextral wrench corridor already proposed for the ophiolite origin in the eastern Vardar zone. The tectonic emplacement of the Sithonia ophiolite involved dextral ENE to SE strike-slip sense of shear and SW and NE reverse thrust sense of shear on mostly steep foliation S1, subhorizontal lineation L1 and associated variably inclined F1 fold axes. This structural grain and kinematics are shared by adjacent Chortiatis island arc magmatic suite and the Melissochori Formation. The coexistence of strike-parallel and thrust components of displacement along discrete dextral strike-slip shear zones and internal deformation of the mentioned units is interpreted to result from a bulk dextral transpressive deformation regime developed in greenschist-facies metamorphic conditions. The back-arc ocean floor previous structural architecture with faults and fracture zones where Kimmeridgian sediments deposited in troughs was used by discrete strike-slip shear zones in which these sediments involved, and the shear zones become the sites for

  4. Modeling the Sedimentary Infill of Lakes in the East African Rift: A Case Study of Multiple versus Single Rift Basin Segments (United States)

    Zhang, C.; Scholz, C. A.


    The sedimentary basins in the East African Rift are considered excellent modern examples for investigating sedimentary infilling and evolution of extensional systems. Some lakes in the western branch of the rift have formed within single-segment systems, and include Lake Albert and Lake Edward. The largest and oldest lakes developed within multi-segment systems, and these include Lake Tanganyika and Lake Malawi. This research aims to explore processes of erosion and sedimentary infilling of the catchment area in single-segment rift (SSR) and multi-segment rift (MSR) systems. We consider different conditions of regional precipitation and evaporation, and assess the resulting facies architecture through forward modeling, using state-of-the-art commercial basin modeling software. Dionisos is a three-dimensional numerical stratigraphic forward modeling software program, which simulates basin-scale sediment transport based on empirical water- and gravity-driven diffusion equations. It was classically used to quantify the sedimentary architecture and basin infilling of both marine siliciclastic and carbonate environments. However, we apply this approach to continental rift basin environments. In this research, two scenarios are developed, one for a MSR and the other for a SSR. The modeled systems simulate the ratio of drainage area and lake surface area observed in modern Lake Tanganyika and Lake Albert, which are examples of MSRs and SSRs, respectively. The main parameters, such as maximum subsidence rate, water- and gravity-driven diffusion coefficients, rainfall, and evaporation, are approximated using these real-world examples. The results of 5 million year model runs with 50,000 year time steps show that MSRs are characterized by a deep water lake with relatively modest sediment accumulation, while the SSRs are characterized by a nearly overfilled lake with shallow water depths and thick sediment accumulation. The preliminary modeling results conform to the features

  5. Evolution of the western East African Rift System reflected in provenance changes of Miocene to Pleistocene synrift sediments (Albertine Rift, Uganda) (United States)

    Schneider, Sandra; Hornung, Jens; Hinderer, Matthias


    Miocene to Pleistocene synrift sediments in the Albertine Graben reflect the complex geodynamic evolution in the Western branch of the East African Rift System. In this study we focus on the provenance of these siliciclastic deposits to identify sediment sources and supply paths with the ultimate goal to reconstruct the exhumation history of different tectonic blocks during prolonged rifting, with specific focus on the uplift of the Rwenzori Mountains in Uganda. We present framework and heavy mineral petrographic data combined with varietal studies of detrital garnet and rutile, based on logged sediment sections on the Ugandan side of Lake Albert (Kisegi-Nyabusosi area). The analyzed sedimentary units have a feldspatho-quartzose composition and distinct variations in heavy mineral assemblages and mineral chemical composition indicating two provenance changes. The Miocene part of the stratigraphy is dominated by garnet, zircon, tourmaline and rutile, whereas Pliocene to Pleistocene sediment yields high amounts of less stable amphibole and epidote. An abrupt switch in heavy mineral assemblages occurs during the early Pliocene ( 5.5-5.0 Ma) and clearly postdates the formation of Palaeolake Obweruka at 8 Ma. Provenance signatures point to major sediment supply from the northeast and subsequently from the southeast. We interpret this first shift as transition from the pre-rift to the syn-rift stage. In this scenario, formation of Palaeolake Obweruka is due to higher humidity in the upper Miocene, rather than forced rifting. A second change of sediment composition is documented by mineral geochemistry and coincides with fragmentation of Palaeolake Obweruka starting at 2.5 Ma. Detrital garnet in sediment of Miocene to Pliocene age is rich in pyrope and almandine and calculated Zr-in-rutile temperatures range between 550 and 950 °C. In contrast, garnet occurring in Pleistocene sediment (Nyabusosi Formation) has a higher spessartine component and rutile thermometry is

  6. Analysis of Adoption Spell of Hybrid Maize in the Central Rift Valley ...

    African Journals Online (AJOL)

    This paper estimates farm household level determinants of the speed of adoption of hybrid maize in the central rift valley of Ethiopia in the framework of the dynamic time on cross-sectional data. Descriptive statistics and duration model were used to study the objectives of the study. The results from descriptive analysis ...

  7. Petroleum systems in rift basins – a collective approach in South-east Asian basins.

    NARCIS (Netherlands)

    Doust, H.; Sumner, D.


    This paper synthesizes some of the main conclusions reached in a recent regional review of the Tertiary basins of Southeast Asia, carried out by Shell. Four distinctive types of petroleum systems, correlating with the four main stages of basin evolution (early to late syn-rift and early to late

  8. Broad accommodation of rift-related extension recorded by dyke intrusion in Saudi Arabia

    KAUST Repository

    Pallister, John S.


    The extensive harrat lava province of Arabia formed during the past 30 million years in response to Red Sea rifting and mantle upwelling. The area was regarded as seismically quiet, but between April and June 2009 a swarm of more than 30,000 earthquakes struck one of the lava fields in the province, Harrat Lunayyir, northwest Saudi Arabia. Concerned that larger damaging earthquakes might occur, the Saudi Arabian government evacuated 40,000 people from the region. Here we use geologic, geodetic and seismic data to show that the earthquake swarm resulted from magmatic dyke intrusion. We document a surface fault rupture that is 8 km long with 91 cm of offset. Surface deformation is best modelled by the shallow intrusion of a north-west trending dyke that is about 10 km long. Seismic waves generated during the earthquakes exhibit overlapping very low- and high-frequency components. We interpret the low frequencies to represent intrusion of magma and the high frequencies to represent fracturing of the crystalline basement rocks. Rather than extension being accommodated entirely by the central Red Sea rift axis, we suggest that the broad deformation observed in Harrat Lunayyir indicates that rift margins can remain as active sites of extension throughout rifting. Our analyses allowed us to forecast the likelihood of a future eruption or large earthquake in the region and informed the decisions made by the Saudi Arabian government to return the evacuees. © 2010 Macmillan Publishers Limited. All rights reserved.

  9. Petrology of rift-related basalts at Bombay High waters, Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Iyer, S.D.

    .39% and FeO super(t) 11.79 to 15.5%. The iron enrichment and the low Mg numbers suggest derivation of these basalts from extensive fractional crystallisation. These basalts are compositionally similar to rift related basaltic rocks associated with the opening...

  10. A Systematic Scoping Study of the Socio-Economic Impact of Rift Valley Fever

    NARCIS (Netherlands)

    Peyre, M.; Chevalier, V.; Abdo-Salem, S.; Velthuis, A.; Antoine-Moussiaux, N.; Thiry, E.; Roger, F.


    Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio-economic impact induced by RVF disease and the attempts to

  11. Hydrogeological aspects of fault zones on various scales in the Roer Valley Rift System.

    NARCIS (Netherlands)

    Bense, V.F.; van Balen, R.T.


    The impact of faults on the groundwater flow system in the Roer Valley Rift System (RVRS) is demonstrated with examples from outcrop scale to regional scale. Faults in the RVRS can form strong barriers to horizontal groundwater flow as well as enhanced vertical groundwater flow paths at the same

  12. Water Hyacinth in the Rift Valley Water Bodies of Ethiopia: Its Distribution, Socioeconomic Importance and Management

    NARCIS (Netherlands)

    Firehun, Y.; Struik, P.C.; Lantinga, E.A.; Taye, T.


    A survey was conducted in the Rift Valley water bodies of Ethiopia from 2009 to 2011 to (i) determine the prevalence, agro-ecological distribution and sources of infestation of water hyacinth, (ii) investigate the socio-economic impact of water hyacinth, and (iii) assess changes in its

  13. Management of water hyacinth (Eichhornia crassipes [Mart.] Solms) using bioagents in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Gebregiorgis, Firehun Yirefu


    This thesis presents a study on management of water hyacinth (Eichhornia crassipes [Mart.] Solms) using insects and fungal pathogens as bioagents. The main goal was to develop an effective biocontrol strategy for water hyacinth in the Rift Valley of Ethiopia. To this end, a field survey was

  14. Rift Valley Fever Risk Map Model and Seroprevalence in Selected Wild Ungulates and Camels from Kenya

    NARCIS (Netherlands)

    Britch, S.C.; Binepal, Y.S.; Ruder, M.G.; Kariithi, H.M.; Linthicum, K.J.; Anyamba, A.; Small, J.L.; Tucker, C.J.; Ateya, L.O.; Oriko, A.A.; Gacheru, S.; Wilson, W.C.


    Since the first isolation of Rift Valley fever virus (RVFV) in the 1930s, there have been multiple epizootics and epidemics in animals and humans in sub-Saharan Africa. Prospective climate-based models have recently been developed that flag areas at risk of RVFV transmission in endemic regions based

  15. Rift Valley Fever Virus Growth Curve Kinetics in Cattle and Sheep Peripheral Blood Monocyte Derived Macrophages (United States)

    Rift Valley fever virus (RVFV), is a mosquito-borne, zoonotic pathogen within genus Phlebovirus, family Bunyaviridae that typically causes outbreaks in sub-Saharan Africa and recently spread to the Arabian Peninsula. In ruminants, RVFV infections cause mass abortion and high mortality rates in neona...

  16. Yield gaps and resource use across farming zones in the central rift valley of Ethiopia

    NARCIS (Netherlands)

    Getnet, Mezegebu; Ittersum, van Martin; Hengsdijk, Huib; Descheemaeker, Katrien


    In the Central Rift Valley (CRV) of Ethiopia, low productive cereal systems and a declining resource base call for options to increase crop productivity and improve resource use efficiency to meet the growing demand of food. We compiled and analysed a large amount of data from farmers’ fields

  17. Identifying rift zones on volcanoes: an example from La Réunion island, Indian Ocean (United States)

    Bonali, Fabio Luca; Corazzato, Claudia; Tibaldi, Alessandro


    We describe a methodology for identifying complex rift zones on recent or active volcanoes, where structures hidden by recent deposits and logistical conditions might prevent carrying out detailed fieldwork. La Réunion island was chosen as a test-site. We used georeferenced topographic maps, aerial photos and digital terrain models to perform a statistical analysis of several morphometric parameters of pyroclastic cones. This provides a great deal of geometric information that can help in distinguishing the localisation and orientation of buried magma-feeding fractures, which constitute the surface expression of rift zones. It also allowed the construction of a complete GIS database of the pyroclastic cones. La Réunion is a perfect example where past and active volcanic rift zones are mostly expressed by clusters of monogenic centres. The data has been validated in the field and compared and integrated with the distribution and geometry of dyke swarms. Results show the presence of several main and secondary rift segments of different ages, locations and orientations, whose origin is discussed considering regional tectonics, local geomorphology, and volcano deformation.

  18. Assessment of conventional oil resources of the East African Rift Province, East Africa, 2016 (United States)

    Brownfield, Michael E.; Schenk, Christopher J.; Klett, Timothy R.; Mercier, Tracey J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Finn, Thomas M.; Le, Phuong A.; Leathers-Miller, Heidi M.


    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 13.4 billion barrels of oil and 4.6 trillion cubic feet of gas in the East African Rift Province of east Africa.

  19. The rift-like structure and asymmetry of the Dead Sea Fault

    NARCIS (Netherlands)

    Smit, J.H.W.; Brun, J.P.; Cloetingh, S.A.P.L.; Ben-Avraham, Z.


    Whereas the Dead Sea Fault is a major continental transform, active since ca. 13-18 Ma ago, it has a rift-like morphology along its southern part. It has been argued that this results from a transtensional component active since 5 Ma ago, due to a regional plate kinematics change. We present the

  20. Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim


    A. K. Eisses, A. M. Kell, G. Kent, N. W. Driscoll, R. E. Karlin, R. L. Baskin, J. N. Louie, S. Pullammanappallil, 2010, Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada: Abstract T33C-2278 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13-17 Dec.

  1. Pesticide use practices among smallholder vegetable farmers in Ethiopian Central Rift Valley

    NARCIS (Netherlands)

    Mengistie, B.T.; Mol, A.P.J.; Oosterveer, P.J.M.


    Pesticide use is a common practice to control pests and diseases in vegetable cultivation, but often at the expense of the environment and human health. This article studies pesticide-buying and use practices among smallholder vegetable farmers in the Central Rift Valley of Ethiopia, using a

  2. Long-distance impact of Iceland plume on Norway’s rifted margin

    National Research Council Canada - National Science Library

    Alexander Koptev; Sierd Cloetingh; Evgueni Burov; Thomas François; Taras Gerya


    ... from the Iceland mantle plume has been the norm in the geological past. In the Northern Atlantic the Iceland plume has a strong long-distance impact on intraplate deformation affecting both onshore and offshore parts of Norway’s rifted margin...


    DEFF Research Database (Denmark)

    Schiffer, Christian; Petersen, Kenni Dinesen

    during extension and form structures within the lower crust. The numerical model is consistent with the observation that passive margins often show dipping sub-Moho structures that are commonly interpreted as remnants of subducted crust emplaced during pre-rift compressional phases of the Wilson cycle...

  4. Spatial distribution of non-clinical Rift Valley fever viral activity in ...

    African Journals Online (AJOL)

    Rift Valley fever (RVF) is an acute zoonotic viral disease of domestic ruminants in mainland Africa and Madagascar. The disease may exist in non-clinical form in apparently health animals. This study was designed to investigate the existence and spatial distribution of non-clinical form of RVF virus (RVFV) activity in wild and ...

  5. Four-segmented Rift Valley fever virus induces sterile immunity in sheep after a single vaccination

    NARCIS (Netherlands)

    Wichgers Schreur, P.J.; Kant-Eenbergen, H.C.M.; Keulen, van L.J.M.; Moormann, R.J.M.; Kortekaas, J.A.


    Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family, causes recurrent outbreaks with severe disease in ruminants and occasionally humans. The virus comprises a segmented genome consisting of a small (S), medium (M) and large (L) RNA segment of negative polarity. The

  6. Broad accommodation of rift-related extension recorded by dyke intrusion in Saudi Arabia (United States)

    Pallister, J.S.; McCausland, W.A.; Jonsson, Sigurjon; Lu, Z.; Zahran, H.M.; El, Hadidy S.; Aburukbah, A.; Stewart, I.C.F.; Lundgren, P.R.; White, R.A.; Moufti, M.R.H.


    The extensive harrat lava province of Arabia formed during the past 30 million years in response to Red Sea rifting and mantle upwelling. The area was regarded as seismically quiet, but between April and June 2009 a swarm of more than 30,000 earthquakes struck one of the lava fields in the province, Harrat Lunayyir, northwest Saudi Arabia. Concerned that larger damaging earthquakes might occur, the Saudi Arabian government evacuated 40,000 people from the region. Here we use geologic, geodetic and seismic data to show that the earthquake swarm resulted from magmatic dyke intrusion. We document a surface fault rupture that is 8 km long with 91 cm of offset. Surface deformation is best modelled by the shallow intrusion of a north-west trending dyke that is about 10 km long. Seismic waves generated during the earthquakes exhibit overlapping very low- and high-frequency components. We interpret the low frequencies to represent intrusion of magma and the high frequencies to represent fracturing of the crystalline basement rocks. Rather than extension being accommodated entirely by the central Red Sea rift axis, we suggest that the broad deformation observed in Harrat Lunayyir indicates that rift margins can remain as active sites of extension throughout rifting. Our analyses allowed us to forecast the likelihood of a future eruption or large earthquake in the region and informed the decisions made by the Saudi Arabian government to return the evacuees.

  7. Feedbacks of lithosphere dynamics and environmental change of the Cenozoic West Antarctic Rift System.

    NARCIS (Netherlands)

    van der Wateren, F.M.; Cloetingh, S.A.P.L.


    This special issue of Global and Planetary Change contains 11 contributions dealing with various aspects of the Cenozoic West Antarctic Rift System. During the last two decades, investigations of the interplay of tectonics and climate greatly improved understanding of Cenozoic global change. Major

  8. Thermal state of the Roer Valley Graben, part of the European Cenozoic Rift System

    NARCIS (Netherlands)

    Luijendijk, E.; ter Voorde, M.; van Balen, R.T.; Verweij, H.; Simmelink, E.


    We performed a detailed analysis of the thermal state of the Cenozoic Roer Valley Graben, the north-western branch of the European Cenozoic Rift System, based on a new set of temperature data. We developed a numerical technique for correcting bottom hole temperatures, including an evaluation of the

  9. Thermal state of the Roer Valley Graben, part of the European Cenozoic Rift System

    NARCIS (Netherlands)

    Luijendijk, E.; ter Voorde, M.; van Balen, R.T.; Verweij, H.; Simmelink, E.


    We performed a detailed analysis of the thermal state of the Cenozoic Roer Valley Graben, the north-western branch of the European Cenozoic Rift System, based on a new set of temperature data. We developed a numerical technique for correcting bottom hole temperatures, including an evaluation of the

  10. Strain distribution across magmatic margins during the breakup stage: Seismicity patterns in the Afar rift zone (United States)

    Brown, C.; Ebinger, C. J.; Belachew, M.; Gregg, T.; Keir, D.; Ayele, A.; Aronovitz, A.; Campbell, E.


    Fault patterns record the strain history along passive continental margins, but geochronological constraints are, in general, too sparse to evaluate these patterns in 3D. The Afar depression in Ethiopia provides a unique setting to evaluate the time and space relations between faulting and magmatism across an incipient passive margin that formed above a mantle plume. The margin comprises a high elevation flood basalt province with thick, underplated continental crust, a narrow fault-line escarpment underlain by stretched and intruded crust, and a broad zone of highly intruded, mafic crust lying near sealevel. We analyze fault and seismicity patterns across and along the length of the Afar rift zone to determine the spatial distribution of strain during the final stages of continental breakup, and its relation to active magmatism and dike intrusions. Seismicity data include historic data and 2005-2007 data from the collaborative US-UK-Ethiopia Afar Geodynamics Project that includes the 2005-present Dabbahu rift episode. Earthquake epicenters cluster within discrete, 50 km-long magmatic segments that lack any fault linkage. Swarms also cluster along the fault-line scarp between the unstretched and highly stretched Afar rift zone; these earthquakes may signal release of stresses generated by large lateral density contrasts. We compare Coulomb static stress models with focal mechanisms and fault kinematics to discriminate between segmented magma intrusion and crank- arm models for the central Afar rift zone.

  11. Exploring determinants of farmers' investments in land management in the Central Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Adimassu Teferi, Z.; Kessler, A.; Hengsdijk, H.


    Land degradation, especially water erosion and nutrient depletion, seriously affects agricultural production in the Central Rift Valley of Ethiopia. Farmers' investments to conserve their land are until now however quite limited. The objective of this study is to identify the major factors that

  12. Pathology Review of Two New Rift Valley Fever Virus Ruminant Models (United States)

    Rift Valley fever virus (RVFV), is a mosquito-borne, zoonotic pathogen within genus Phlebovirus, family Bunyaviridae that typically causes outbreaks in sub-Saharan Africa and recently spread to the Arabian Peninsula. In ruminants, RVFV infections cause mass abortion and high mortality rates in neona...

  13. Sero-surveillance of Rift Valley fever in sheep and goat flocks in ...

    African Journals Online (AJOL)

    The surveillance of Rift Valley Fever (RVF) was carried out in the risk areas of Kenya by monitoring free range/migratory and sedentary farm sheep and goat herds for antibodies to RVF virus (RVFV). A total of 986 serum samples were collected and analyzed from farms in Molo, (where no outbreaks has ever been previously ...

  14. Geophysical expression of elements of the Rio Grande rift in the northeast Tusas Mountains - Preliminary interpretations (United States)

    Drenth, Benjamin J.; Turner, Kenzie J.; Thompson, Ren A.; Grauch, V. J.; Cosca, Michael A.; Lee, John


    New interpretations of the nature of the Rio Grande rift and pre-existing rocks in the northeast Tusas Mountains region are derived from new and existing gravity and aeromagnetic data. 12-15 mGal amplitude gravity lows are interpreted to mainly reflect large thicknesses of the upper Oligocene to upper Miocene, syn-rift Los Pinos Formation and possibly significant amounts of the Eocene El Rito Formation. The Broke Off Mountain sub basin, named after the location of its greatest inferred depth, is interpreted to be a ~40 km long and ~13 km wide structure elongated in a northwest trend at the western margin of the San Luis Basin. The sub basin is interpreted to contain a maximum combined thickness of 900-2300 m of the Los Pinos Formation and El Rito Formation, with the Los Pinos Formation constituting the majority of the section. Sub basin age is constrained to be older than 21.6 ± 1.4 Ma, the age of a Hinsdale Formation basalt flow that caps the Los Pinos Formation section at Broke Off Mountain. This age constraint and surface geology indicate a pre- and early-rift age. The structural fabric of the northeast Tusas Mountains region is dominated by northwest-trending normal faults, as indicated by geologic mapping and interpretation of aeromagnetic data. Preliminary analysis of the aeromagnetic data suggests that lineaments, possibly reflecting faulting, trend through volcanic rocks as young as Pliocene in age. If correct, these interpretations challenge commonly held beliefs regarding two stages in the structural style of rifting, where early (Oligocene-Miocene) rifting was characterized by broad, shallow basins bounded by northwest-trending faults and later (Miocene-Pliocene) rifting was characterized by deep, narrow basins bounded by north-trending faults. The Broke Off Mountain sub basin is a counter example of a pre- and early-rift, deep and narrow basin. We hypothesize that the Broke Off Mountain sub basin may represent a southward extension of the Monte Vista

  15. Lithospheric low-velocity zones associated with a magmatic segment of the Tanzanian Rift, East Africa (United States)

    Plasman, M.; Tiberi, C.; Ebinger, C.; Gautier, S.; Albaric, J.; Peyrat, S.; Déverchère, J.; Le Gall, B.; Tarits, P.; Roecker, S.; Wambura, F.; Muzuka, A.; Mulibo, G.; Mtelela, K.; Msabi, M.; Kianji, G.; Hautot, S.; Perrot, J.; Gama, R.


    Rifting in a cratonic lithosphere is strongly controlled by several interacting processes including crust/mantle rheology, magmatism, inherited structure and stress regime. In order to better understand how these physical parameters interact, a 2 yr long seismological experiment has been carried out in the North Tanzanian Divergence (NTD), at the southern tip of the eastern magmatic branch of the East African rift, where the southward-propagating continental rift is at its earliest stage. We analyse teleseismic data from 38 broad-band stations ca. 25 km spaced and present here results from their receiver function (RF) analysis. The crustal thickness and Vp/Vs ratio are retrieved over a ca. 200 × 200 km2 area encompassing the South Kenya magmatic rift, the NTD and the Ngorongoro-Kilimanjaro transverse volcanic chain. Cratonic nature of the lithosphere is clearly evinced through thick (up to ca. 40 km) homogeneous crust beneath the rift shoulders. Where rifting is present, Moho rises up to 27 km depth and the crust is strongly layered with clear velocity contrasts in the RF signal. The Vp/Vs ratio reaches its highest values (ca. 1.9) beneath volcanic edifices location and thinner crust, advocating for melting within the crust. We also clearly identify two major low-velocity zones (LVZs) within the NTD, one in the lower crust and the second in the upper part of the mantle. The first one starts at 15-18 km depth and correlates well with recent tomographic models. This LVZ does not always coexist with high Vp/Vs ratio, pleading for a supplementary source of velocity decrease, such as temperature or composition. At a greater depth of ca. 60 km, a mid-lithospheric discontinuity roughly mimics the step-like and symmetrically outward-dipping geometry of the Moho but with a more slanting direction (NE-SW) compared to the NS rift. By comparison with synthetic RF, we estimate the associated velocity reduction to be 8-9 per cent. We relate this interface to melt ponding

  16. The rift architecture and extensional tectonics of the South China Sea (United States)

    Cameselle, Alejandra L.; Ranero, César R.; Barckhausen, Udo; Franke, Dieter


    Non-volcanic rifted continental margins are classically described as the product of lithospheric stretching and breakup leading to mantle exhumation, and subsequent seafloor spreading. However, recent studies question this model and indicate a wider range of structural evolutions, that challenge the existing model (e.g. Australia-Antarctic Rift System (Direen et al. 2007, 2011); the Tyrrhenian basin (Prada et al., 2014) or the South China Sea (Cameselle et al. 2015)). Rifting in the South China Sea developed from a series of extensional events, from early Eocene to Late Oligocene, resulting in a V-shape oceanic basin affected by the occurrence of several spreading centers, ridges, transform faults and post-spreading volcanism. In recent years, this marginal basin - the largest in East Asia - has increasingly become one of the key sites for the study of rifting and continental break-up. Its relative small size - compared to many classic, Atlantic-type continental margin settings - allows to easily match conjugated rifted margins and its relative youth promotes the preservation of its original nature. To examine the rifting evolution of the South China Sea, we have reprocessed with modern algorithms multichannel seismic profiles acquired during Sonne49 and BGR84 cruises across the three major subbasins: NW, SW and East subbasins. State-of-the-art of processing techniques have been used to increase the signal to noise ratio, including Tau-P and Wiener predictive deconvolution, multiple attenuation by both radon filtering and wave-equation-based surface-related multiple elimination (SRME) and time migration. To complement seismic interpretation, available vintage multichannel seismic data have been reprocessed with a post-stack flow, including Wiener deconvolution, FK-filtering, space and time variant band-pass filter and time migration. The improving quality of the seismic images shows a range of features including post-rift and syn-rift sediments, the structure of

  17. The life cycle of continental rifts: Numerical models of plate tectonics and mantle convection. (United States)

    Ulvrova, Martina; Brune, Sascha; Williams, Simon


    Plate tectonic processes and mantle convection form a self-organized system whose surface expression is characterized by repeated Wilson cycles. Conventional numerical models often capture only specific aspects of plate-mantle interaction, due to imposed lateral boundary conditions or simplified rheologies. Here we study continental rift evolution using a 2D spherical annulus geometry that does not require lateral boundary conditions. Instead, continental extension is driven self-consistently by slab pull, basal drag and trench suction forces. We use the numerical code StagYY to solve equations of conservation of mass, momentum and energy and transport of material properties. This code is capable of computing mantle convection with self-consistently generated Earth-like plate tectonics using a pseudo-plastic rheology. Our models involve an incompressible mantle under the Boussinesq approximation with internal heat sources and basal heating. Due to the 2D setup, our models allow for a comparably high resolution of 10 km at the mantle surface and 15 km at the core mantle boundary. Viscosity variations range over 7 orders of magnitude. We find that the causes for rift initiation are often related to subduction dynamics. Some rifts initiate due to increasing slab pull, others because of developing trench suction force, for instance by closure of an intra-oceanic back-arc basin. In agreement with natural settings, our models reproduce rifts forming in both young and old collision zones. Our experiments show that rift dynamics follow a characteristic evolution, which is independent of the specific setting: (1) continental rifts initiate during tens of million of years at low extension rates (few millimetres per year) (2) the extension velocity increases during less than 10 million years up to several tens of millimetres per year. This speed-up takes place before lithospheric break-up and affects the structural architecture of rifted margins. (3) high divergence rates

  18. Biomass resources for heat and electricity in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Christou, M.; Panoutsou, C. [Center for Renewable Energy Sources (CRES), Pikermi (Greece); Lychnaras, V. [Agricultural Univ. of Greece, Athens (Greece). Laboratory of Agribusiness Management


    The aim of this study is to present bioenergy pathways for the heat and electricity markets in Greece. Bioenergy in Greece follows a rising trend the last ten years. From small agro-industrial applications covering mainly process and space heat, new cogeneration plants were initiated in the waste and sewage treatment sectors. There are good opportunities for biomass heat applications in the commercial sector (tourist settlements, public buildings, etc.) as well as for co-firing biomass in the lignite power stations. The first electricity plants from bioenergy (CHP) were initiated on 1997, after the initiation of the strong support measures. According to the National Statistic Service, in 2001 bio energy use was estimated at 39 PJ/year, about 3.4% of the total primary energy consumption in the country by that year. Of this, biomass (mostly wood consumed directly in the domestic/residential sector) accounted for 64.4%, or 0.946 Mtoe. Domestic use of wood (burning of wood in open heaths for cooking, water and space heating) accounted for about 74% (0.70 Mtoe) of total biomass energy production. The remaining 26% (0.24 Mtoe) was produced by the combustion of wood by-products and agricultural residues, and the utilisation of biogas produced in landfills, agro-food industries and municipal wastewater treatment plants. Traditional biomass resources in Greece include agricultural crops, crop and forest residues, agro-industrial residues, animal and municipal wastes and energy crops. It was estimated that approximately 3.8 million dry tones of field crop and arboricultural residues are theoretically available for energy production as well as 600,000 dry tones of agro-industrial residues, with a respective total energy potential of 69 PJ/year and 10 PJ/year. Intensive livestock farming results in a daily production of 3,200 m{sup 3}, 491 m{sup 3} and 2,000 m{sup 3} animal wastes from cattle, pig and poultry breeding, respectively, with a biogas potential of 240,000 m{sup 3

  19. Birth of Olympic flame: Ancient Greece and European identity (II

    Directory of Open Access Journals (Sweden)

    Malešević Miroslava


    Full Text Available The anti-Chinese protests that were organized throughout European cities fol­lowing the route of the Olympic torch from Athens to Beijing, and the conflicts that erupted with strong emotions on both sides between the protestors and the Chinese citizens, will without a doubt remain a lasting memory of the 2008 Olympic games. Regardless of these protests' justified motives, there is a visible paradoxical role-switch in the scenes that circled the globe for months: the Olympic torch and Olympic idea, were being defended by China as a highest value and the source of their own past and identity, and attacked by the people (Europeans on whose land that very idea had been created and nurtured for over a hundred years. How should these contradictory images be understood? How did it come to this that the Chinese view themselves as the keepers of the Olympic tradition, that the pride of the Chinese nation, focused in that flame, gets hurt in attempts of European protestors to put it out? The modern Olympic Games, founded in 1896, were one of the echoes of a centuries' long Western European fascination with the Antique. This phenomenon of the Antique admiration has brought about a redefining of the European civilization's past, the abandoning the biblical narrative and the gradual creation of a secular story that we call modern history, in which Greece and Rome have become the main references of origin. The same process influenced the formation of national states that perceive, apart from their own histories, a collective cultural origin in Ancient Greece. Of course, the Galls, Francs or Germans had little in common with ancient Greeks; but modern European nations unite this fictional image of the Antique with the firm belief that it is the source of their cultural identity. For instance, not only did the 18th century French and English believe that they originated from ancient Greece but they managed to successfully 'sell' that story to modern Greeks

  20. Public Perception of Climate Risk: The Case of Greece (United States)

    Voskaki, Asimina; Tsermenidis, Konstantinos


    Climate change is generally considered as one of the greatest challenges our world is facing. In the case of Greece climatic change seems to be associated with sea level rise, increase in temperature, variation in precipitation patterns, and extreme weather events. As a result of climate pattern changes a series of consequences are expected in areas involving build environment, infrastructures, health and various sectors of the economy. Even though climate change is probably going to affect Greece in terms of human welfare and economic growth, public perception and attitude do not always identify it as the most important, amongst others, environmental area of concern, or compared to various socio-economic issues. Considering that topics related to climate change involve a certain degree of uncertainty public perception seems to be important when dealing with adaptation strategies to manage or prevent risks from climate change impact and therefore people's reaction to risks seem to be an issue of great importance in future policy planning and implementation. The key issue of this paper is to investigate and analyse public perception in Greece as regards to climate change risk. Through a questionnaire survey this research investigates people's understanding, specific knowledge, opinion, awareness, emotions, behavior with regards to climate change risks and their willingness to pay in order to minimize or prevent risk. In addition, it examines people's willingness to alter current lifestyle and adapt to a changing climate. The information derived from survey data concern the topics and the perceived importance of the causes of the climate change between certain groups of people; the analysis of the data is focused on the correlation between perceived risk and knowledge about the issues involved. Rather than applying a specific technique extensively, we choose to deploy a number of methodologies with which we are able to draw different aspects from the data. To this

  1. Tectonic inheritance in the development of the Kivu - north Tanganyika rift segment of the East African Rift System: role of pre-existing structures of Precambrian to early Palaeozoic origin. (United States)

    Delvaux, Damien; Fiama Bondo, Silvanos; Ganza Bamulezi, Gloire


    The present architecture of the junction between the Kivu rift basin and the north Tanganyika rift basin is that of a typical accommodation zone trough the Ruzizi depression. However, this structure appeared only late in the development of the Western branch of the East African Rift System and is the result of a strong control by pre-existing structures of Precambrian to early Palaeozoic origin. In the frame of a seismic hazard assessment of the Kivu rift region, we (Delvaux et al., 2016) constructed homogeneous geological, structural and neotectonic maps cross the five countries of this region, mapped the pre-rift, early rift and Late Quaternary faults and compiled the existing knowledge on thermal springs (assumed to be diagnostic of current tectonic activity along faults). We also produced also a new catalogue of historical and instrumental seismicity and defined the seismotectonic characteristics (stress field, depth of faulting) using published focal mechanism data. Rifting in this region started at about 11 Ma by initial doming and extensive fissural basaltic volcanism along normal faults sub-parallel to the axis of the future rift valley, as a consequence of the divergence between the Nubia and the Victoria plate. In a later stage, starting around 8-7 Ma, extension localized along a series of major border faults individualizing the subsiding tectonic basins from the uplifting rift shoulders, while lava evolved towards alkali basaltic composition until 2.6 Ma. During this stage, initial Kivu rift valley was extending linearly in a SSW direction, much further than its the actual termination at Bukavu, into the Mwenga-Kamituga graben, up to Namoya. The SW extremity of this graben was linked via a long oblique transfer zone to the central part of Lake Tanganyika, itself reactivating an older ductile-brittle shear zone. In the late Quaternary-early Holocene, volcanism migrated towards the center of the basin, with the development of the Virunga volcanic massif

  2. The stress shadow induced by the 1975-1984 Krafla rifting episode

    KAUST Repository

    Maccaferri, F.


    It has been posited that the 1975–1984 Krafla rifting episode in northern Iceland was responsible for a significant drop in the rate of earthquakes along the Húsavík-Flatey Fault (HFF), a transform fault that had previously been the source of several magnitude 6–7 earthquakes. This compelling case of the existence of a stress shadow has never been studied in detail, and the implications of such a stress shadow remain an open question. According to rate-state models, intense stress shadows cause tens of years of low seismicity rate followed by a faster recovery phase of rate increase. Here, we compare the long-term predictions from a Coulomb stress model of the rifting episode with seismological observations from the SIL catalog (1995–2011) in northern Iceland. In the analyzed time frame, we find that the rift-induced stress shadow coincides with the eastern half of the fault where the observed seismicity rates are found to be significantly lower than expected, given the historical earthquake activity there. We also find that the seismicity rates on the central part of the HFF increased significantly in the last 17 years, with the seismicity progressively recovering from west to east. Our observations confirm that rate-state theory successfully describes the long-term seismic rate variation during the reloading phase of a fault invested by a negative Coulomb stress. Coincident with this recovery, we find that the b-value of the frequency-magnitude distribution changed significantly over time. We conclude that the rift-induced stress shadow not only decreased the seismic rate on the eastern part of the HFF but also temporarily modified how the system releases seismic energy, with more large magnitude events in proportion to small ones. This behavior is currently being overturned, as rift-induced locking is now being compensated by tectonic forcing.

  3. Episodic kinematics in continental rifts modulated by changes in mantle melt fraction (United States)

    Lamb, Simon; Moore, James D. P.; Smith, Euan; Stern, Tim


    Oceanic crust is created by the extraction of molten rock from underlying mantle at the seafloor ‘spreading centres’ found between diverging tectonic plates. Modelling studies have suggested that mantle melting can occur through decompression as the mantle flows upwards beneath spreading centres, but direct observation of this process is difficult beneath the oceans. Continental rifts, however—which are also associated with mantle melt production—are amenable to detailed measurements of their short-term kinematics using geodetic techniques. Here we show that such data can provide evidence for an upwelling mantle flow, as well as information on the dimensions and timescale of mantle melting. For North Island, New Zealand, around ten years of campaign and continuous GPS measurements in the continental rift system known as the Taupo volcanic zone reveal that it is extending at a rate of 6-15 millimetres per year. However, a roughly 70-kilometre-long segment of the rift axis is associated with strong horizontal contraction and rapid subsidence, and is flanked by regions of extension and uplift. These features fit a simple model that involves flexure of an elastic upper crust, which is pulled downwards or pushed upwards along the rift axis by a driving force located at a depth greater than 15 kilometres. We propose that flexure is caused by melt-induced episodic changes in the vertical flow forces that are generated by upwelling mantle beneath the rift axis, triggering a transient lower-crustal flow. A drop in the melt fraction owing to melt extraction raises the mantle flow viscosity and drives subsidence, whereas melt accumulation reduces viscosity and allows uplift—processes that are also likely to occur in oceanic spreading centres.

  4. Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future.

    Directory of Open Access Journals (Sweden)

    Tracie A Seimon

    Full Text Available Batrachochytrium dendrobatidis (Bd, the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth's most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925-1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions

  5. Numerical modeling of seismicity and geodynamics of the Kachchh rift zone, Gujarat, India (United States)

    Vorobieva, Inessa; Mandal, Prantik; Gorshkov, Alexander


    The numerical block-and-fault model of lithosphere dynamics and seismicity (BAFD) is used to understand crustal motion and features of the observed seismicity in the Kachchh rift zone, Gujarat, Western India. The block-model allows simulating seismicity and geodynamics simultaneously unlike other modeling approaches for studying seismicity or geodynamics. The model structure of Kachchh rift zone is composed of seven major crustal blocks separated by fault planes. Based on the orientation of boundary crustal block movements, we develop a set of numerical experiments to analyze the spatial distribution of earthquakes, frequency-to-magnitude relationships, earthquake focal mechanisms, velocity field, and fault slip rates in the model. The main results of our modeling suggest that an NNW-SSE trending compression is a principal driving force in the Kachchh rift zone that explains basic features of the regional seismicity, direction of block motions, and the presence of an extensional stress regime associated with the Cambay rift zone. Large synthetic events occur on the fault segments associated with the Allah-Bund fault, Katrol hill fault and north Wagad fault which have been causative faults for the 1819 Mw7.7 Allah-Bund, 1956 Mw6.0 Anjar and 2001 Mw7.7 Bhuj earthquakes. The frequency-magnitude distribution for both synthetic seismicity and observed seismicity shows a similar slope. The focal mechanisms of the synthetic events are found to be consistent with those of earthquakes in the region. A special attention has been paid to study long-term and post-seismic deformations. Our results are in a qualitative agreement with the GPS post-seismic observations in the Kachchh rift zone. We infer that the observed seismicity and crustal block motions are a consequence of the dynamics of the entire regional fault and block system rather than that of a single causative fault only.

  6. Tectono-stratigraphic evolution and crustal architecture of the Orphan Basin during North Atlantic rifting (United States)

    Gouiza, Mohamed; Hall, Jeremy; Welford, J. Kim


    The Orphan Basin is located in the deep offshore of the Newfoundland margin, and it is bounded by the continental shelf to the west, the Grand Banks to the south, and the continental blocks of Orphan Knoll and Flemish Cap to the east. The Orphan Basin formed in Mesozoic time during the opening of the North Atlantic Ocean between eastern Canada and western Iberia-Europe. This work, based on well data and regional seismic reflection profiles across the basin, indicates that the continental crust was affected by several extensional episodes between the Jurassic and the Early Cretaceous, separated by events of uplift and erosion. The preserved tectono-stratigraphic sequences in the basin reveal that deformation initiated in the eastern part of the Orphan Basin in the Jurassic and spread towards the west in the Early Cretaceous, resulting in numerous rift structures filled with a Jurassic-Lower Cretaceous syn-rift succession and overlain by thick Upper Cretaceous to Cenozoic post-rift sediments. The seismic data show an extremely thinned crust (4-16 km thick) underneath the eastern and western parts of the Orphan Basin, forming two sub-basins separated by a wide structural high with a relatively thick crust (17 km thick). Quantifying the crustal architecture in the basin highlights the large discrepancy between brittle extension localized in the upper crust and the overall crustal thinning. This suggests that continental deformation in the Orphan Basin involved, in addition to the documented Jurassic and Early Cretaceous rifting, an earlier brittle rift phase which is unidentifiable in seismic data and a depth-dependent thinning of the crust driven by localized lower crust ductile flow.

  7. Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China (United States)

    Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan


    The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

  8. From Rifting of a volcanic province to Oceanic Spreading in the Andaman Sea, South-East Asia. (United States)

    Jourdain, A.; Singh, S. C.; Klinger, Y.


    The Andaman Sea is an enigmatic feature in the Indian Ocean region. It contains the volcanic provinces of Alcock and Sewell Rises and an active spreading center. The recent rifting in the Andaman Sea initiated 4.5 Ma ago, rifting the Alcock and Seawell Rises that were formed by extensive volcanism between 23-16 Ma. The spreading started with a full spreading rate of 1.6 cm/yr and increased to 3.8 cm/yr in the last 2.5 Ma. We have access to high-resolution deep seismic reflection data crossing the whole spreading center from the rifted volcanic provinces to the spreading center. The data show the whole oceanic crust up to the Moho. The Andaman Sea is covered with a thick pile of sediments that record the tectonic history of the rift system up to the spreading axis, allowing to decipher the whole process from rifting to spreading for the first time. We see a very rapid phase of transition from the rifting of the rises to the spreading in less than 20 km. Then a succession of at least 7 half-grabens is well recorded by the sediments on both sides of the spreading center. These half grabens are separated by outward tilted low angle detachment faults, which form the base of steeply dipping normal faults due to stretching. These low angle faults seem to connect with axial magma chambers that control evolution of the rift valley. We find that new detachment faults develop every 350,000 years, forming a new rift valley. The images of active normal faults within the central rift valley allow us to quantify the formation of oceanic crust by tectonic versus magmatic processes.

  9. Rift processes and crustal structure of the Amundsen Sea Embayment, West Antarctica, from 3D potential field modelling (United States)

    Kalberg, Thomas; Gohl, Karsten; Eagles, Graeme; Spiegel, Cornelia


    The Amundsen Sea Embayment of West Antarctica is of particular interest as it provides critical geological boundary conditions in better understanding the dynamic behavior of the West Antarctic Ice Sheet, which is undergoing rapid ice loss in the Amundsen Sea sector. One of the highly debated hypothesis is whether this region has been affected by the West Antarctic Rift System, which is one of the largest in the world and the dominating tectonic feature in West Antarctica. Previous geophysical studies suggested an eastward continuation of this rift system into the Amundsen Sea Embayment. This geophysical study of the Amundsen Sea Embayment presents a compilation of data collected during two RV Polarstern expeditions in the Amundsen Sea Embayment of West Antarctica in 2006 and 2010. Bathymetry and satellite-derived gravity data of the Amundsen Sea Embayment complete the dataset. Our 3-D gravity and magnetic models of the lithospheric architecture and development of this Pacific margin improve previous interpretations from 2-D models of the region. The crust-mantle boundary beneath the continental rise and shelf is between 14 and 29 km deep. The imaged basement structure can be related to rift basins within the Amundsen Sea Embayment, some of which can be interpreted as products of the Cretaceous rift and break-up phase and some as products of later propagation of the West Antarctic Rift System into the region. An estimate of the flexural rigidity of the lithosphere reveals a thin elastic thickness in the eastern embayment which increases towards the west. The results are comparable to estimates in other rift systems such as the Basin and Range province or the East African Rift. Based on these results, we infer an arm of the West Antarctic Rift System is superposed on a distributed Cretaceous rift province in the Amundsen Sea Embayment. Finally, the embayment was affected by magmatism from discrete sources along the Pacific margin of West Antarctica in the Cenozoic.

  10. Statistical evaluation of the simulated convective activity over Central Greece (United States)

    Kartsios, Stergios; Kotsopoulos, Stylianos; Karacostas, Theodore S.; Tegoulias, Ioannis; Pytharoulis, Ioannis; Bampzelis, Dimitrios


    In the framework of the project DAPHNE (, the non-hydrostatic Weather Research and Forecasting model with the Advanced Research dynamic solver (WRF-ARW, version 3.5.1) is used to produce very high spatiotemporal resolution simulations of the convective activity over Thessaly plain and hence, enhancing our knowledge on the impact of high resolution elevation and land use data in the moist convection. The expecting results act as a precursor for the potential applicability of a planned precipitation enhancement program. The three model domains, covering Europe, the Mediterranean Sea and northern Africa (d01), the wider area of Greece (d02) and Thessaly region-central Greece (d03), are used at horizontal grid-spacings of 15km, 5km and 1km respectively. ECMWF operational analyses at 6-hourly intervals (0.25ox0.25o lat.-long.) are imported as initial and boundary conditions of the coarse domain, while in the vertical, 39 sigma levels (up to 50 hPa) are used, with increased resolution in the boundary layer. Microphysical processes are represented by WSM6 scheme, sub-grid scale convection by Kain-Fritsch scheme, longwave and shortwave radiation by RRTMG scheme, surface layer by Monin-Obukhov (MM5), boundary layer by Yonsei University and soil physics by NOAH Unified model. Six representative days with different upper-air synoptic circulation types are selected, while high resolution (3'') elevation data from the Shuttle Radar Topography Mission (SRTM - version 4) are inserted in the innermost domain (d03), along with the Corine Land Cover 2000 raster data (3''x3''). The aforementioned data sets are used in different configurations, in order to evaluate the impact of each one on the simulated convective activity in the vicinity of Thessaly region, using a grid of available meteorological stations in the area. For each selected day, four (4) sensitivity simulations are performed, setting a total number of 24 runs. Finally, the best configuration provides

  11. Pre-existing normal faults have limited control on the rift geometry of the northern North Sea (United States)

    Claringbould, Johan S.; Bell, Rebecca E.; Jackson, Christopher A.-L.; Gawthorpe, Robert L.; Odinsen, Tore


    Many rifts develop in response to multiphase extension with numerical and physical models suggesting that reactivation of first-phase normal faults and rift-related variations in bulk crustal rheology control the evolution and final geometry of subsequent rifts. However, many natural multiphase rifts are deeply buried and thus poorly exposed in the field and poorly imaged in seismic reflection data, making it difficult to test these models. Here we integrate recent 3D seismic reflection and borehole data across the entire East Shetland Basin, northern North Sea, to constrain the long-term, regional development of this multiphase rift. We document the following key stages of basin development: (i) pre-Triassic to earliest Triassic development of multiple sub-basins controlled by widely distributed, NNW- to NE-trending, east- and west-dipping faults; (ii) Triassic activity on a single major, NE-trending, west-dipping fault located near the basins western margin, and formation of a large half-graben; and (iii) Jurassic development of a large, E-dipping, N- to NE-trending half-graben near the eastern margin of the basin, which was associated with rift narrowing and strain focusing in the Viking Graben. In contrast to previous studies, which argue for two discrete periods of rifting during the Permian-Triassic and Late Jurassic-Early Cretaceous, we find that rifting in the East Shetland Basin was protracted from pre-Triassic to Cretaceous. We find that, during the Jurassic, most pre-Jurassic normal faults were buried and in some cases cross-cut by newly formed faults, with only a few being reactivated. Previously developed faults thus had only a limited control on the evolution and geometry of the later rift. We instead argue that strain migration and rift narrowing was linked to the evolving thermal state of the lithosphere, an interpretation supporting the predictions of lithosphere-scale numerical models. Our study indicates that additional regional studies of

  12. Mapping hyper-extended rift systems offshore and onshore: insights from the Bay of Biscay- Western Pyrenees (United States)

    Tugend, Julie; Manatschal, Gianreto; Kusznir, Nicolas J.; Masini, Emmanuel; Thinon, Isabelle


    Research conducted at present-day passive continental margins shows more varied crustal architectures than previously assumed. New seismic data together with drill-holes have revealed the occurrence of extremely thinned continental crust in the distal part of the margin as well as exhumed serpentinised sub-continental mantle oceanwards. In addition the understanding of the formation of hyper-extended rift systems has also greatly benefited from the study of onshore analogs preserved in mountain belts. The Bay of Biscay and Western Pyrenees correspond to a Lower Cretaceous rift system leading to the development of hyper-extended domains and ultimately oceanic crust in the Bay of Biscay. This domain represents one of the best natural laboratories to study the formation processes and evolution of hyper-extended domains. During late Cretaceous compression, these rifted domains were inverted resulting in the present-day Pyrenean mountain belt. In this contribution, we present a new paleogeographic map of the Bay of Biscay-Pyrenean rift system. We integrate results from previous works and new work using different mapping methods to distinguish distinctive crustal domains related to hyper-extended systems both offshore and onshore. We combine seismic interpretations with gravity anomaly inversion and residual depth anomaly analysis to distinguish the different crustal domains across the offshore margin. Onshore, we use an innovative approach based on observations from present-day rifted margin architecture associated with classical field work to map the former hyper-extended domains. Another outcome of this work is the creation of a crustal thickness map using gravity inversion linking offshore and onshore domains from the Bay of Biscay to that of the Western-Pyrenees. This multidisciplinary approach enables us to investigate the spatial and temporal evolution of the Bay of Biscay rift system with the aim of better understanding the formation of hyper-extended domains

  13. [Art-chance and art-experience in classical Greece]. (United States)

    Ban, Deokjin


    In Classical Greece, works defining the nature of art appeared in the various disciplines like medicine, rhetoric, dietetics, architecture and painting. Hippocratic authors tried to show that an art of medicine existed indeed. They contrasted the concept of art with that of chance, not experience that Plato and Aristotle distinguished from art. In fact there are similarities and discrepancies between Hippocratic epistemology and Platoic epistemology. Hippocratic authors maintained that the products of chance were not captured by art. They distinguished the domain of art charactered by explanatory knowledge and prediction from the domain of chance ruled by the unexplained and the unforeseeable. They minimized the role of luck and believed the role of art. Hippocratic authors thought that professional ability contained both knowledge and experience. In Hippocratic corpus, experience is a synonym of competence and usually has a positive meaning. But Plato gave empirical knowledge the disdainful sense and decided a ranking between two types of knowledge. Both Hippocratic authors and Plato held that a genuine art had connection with explanatory knowledge of the nature of its subject matter. A common theme that goes through arguments about art-chance and art-chance is the connection between art and nature. Hippocratic authors and Plato regarded art as a highly systematic process. Art provides us with general and explanatory knowledge of human nature. Art and nature is a mutual relationship. The systematic understanding of nature helps us gain the exactness of art and an exact art helps us understand nature well.

  14. Italian musicians in Greece during the nineteenth century

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    Romanou Ekaterini


    Full Text Available In Greece, the monophonic chant of the Orthodox church and its neumatic notation have been transmitted as a popular tradition up to the first decades of the 20th century. The transformation of Greek musical tradition to a Western type of urban culture and the introduction of harmony, staff notation and western instruments and performance practices in the country began in the 19th century. Italian musicians played a central role in that process. A large number of them lived and worked on the Ionian Islands. Those Italian musicians have left a considerable number of transcriptions and original compositions. Quite a different cultural background existed in Athens. Education was in most cases connected to the church - the institution that during the four centuries of Turkish occupation kept Greeks united and nationally conscious. The neumatic notation was used for all music sung by the people, music of both western and eastern origin. The assimilation of staff notation and harmony was accelerated in the last quarter of the 19th century. At the beginning of the 20th century in Athens a violent cultural clash was provoked by the reformers of music education all of them belonging to German culture. The clash ended with the displacement of the Italian and Greek musicians from the Ionian Islands working at the time in Athens, and the defamation of their fundamental work in music education.

  15. [Fertility and female employment in Greece: a microeconomic model]. (United States)

    Symeonidou, H; Magdalinos, M


    The National Social Research Center of Greece applied November 1984-February 1985 data on 3193 women to a micro-economic model which achieves more efficacious estimation and test procedures and separates useful information from political decisions. The researchers compared the behavior of women from three areas: Athens, other urban regions, and rural areas. Specifically, they wanted to examine the relationship between fertility and women's employment in greater Athens. The model assumes that each woman maximizes her utility which is a function of three factors: family size, free time (leisure), and consumer goods. The test to detect specification errors indicated structural differences between urban and rural areas and heteroscedasticity in the supply equation for work and the demand equation for children. The final model with five structural and four variance equations confirmed that employment affects fertility directly and through women's sex-role attitudes. The mean number of live births, desired family size, and ideal family size were lower in Athens, greater in rural areas, and at an intermediary level in other urban regions. Fertility in Athens and women's employment were not significantly different than that in other urban area. The differences in women's employment were much greater between towns and rural areas, probably because many women in rural areas work without a salary in the family's business. The final model did not find fertility to have an overall significant direct effect on employment but did find it had a significant indirect effect in rural areas due to attitudes toward sexual roles.

  16. Breathing modes of Kolumbo submarine volcano (Santorini, Greece). (United States)

    Bakalis, Evangelos; Mertzimekis, Theo J; Nomikou, Paraskevi; Zerbetto, Francesco


    Submarine volcanoes, such as Kolumbo (Santorini, Greece) are natural laboratories for fostering multidisciplinary studies. Their investigation requires the most innovative marine technology together with advanced data analysis. Conductivity and temperature of seawater were recorded directly above Kolumbo's hydrothermal vent system. The respective time series have been analyzed in terms of non-equilibrium techniques. The energy dissipation of the volcanic activity is monitored by the temperature variations of seawater. The venting dynamics of chemical products is monitored by water conductivity. The analysis of the time series in terms of stochastic processes delivers scaling exponents with turning points between consecutive regimes for both conductivity and temperature. Changes of conductivity are shown to behave as a universal multifractal and their variance is subdiffusive as the scaling exponents indicate. Temperature is constant over volcanic rest periods and a universal multifractal behavior describes its changes in line with a subdiffusive character otherwise. The universal multifractal description illustrates the presence of non-conservative conductivity and temperature fields showing that the system never retains a real equilibrium state. The existence of a repeated pattern of the combined effect of both seawater and volcanic activity is predicted. The findings can shed light on the dynamics of chemical products emitted from the vents and point to the presence of underlying mechanisms that govern potentially hazardous, underwater volcanic environments.

  17. Forecasting magma-chamber rupture at Santorini volcano, Greece. (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust


    How much magma needs to be added to a shallow magma chamber to cause rupture, dyke injection, and a potential eruption? Models that yield reliable answers to this question are needed in order to facilitate eruption forecasting. Development of a long-lived shallow magma chamber requires periodic influx of magmas from a parental body at depth. This redistribution process does not necessarily cause an eruption but produces a net volume change that can be measured geodetically by inversion techniques. Using continuum-mechanics and fracture-mechanics principles, we calculate the amount of magma contained at shallow depth beneath Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini's shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano.

  18. Stakeholder analysis in pharmacogenomics and genomic medicine in Greece. (United States)

    Mitropoulou, Christina; Mai, Yuan; van Schaik, Ron H; Vozikis, Athanassios; Patrinos, George P


    The pace of discoveries and advances in genomic research is not reflected in the pace of their translation and incorporation into day-to-day clinical medicine to individualize healthcare decision-making processes. One of the main obstacles is the poor understanding of the policies and the key stakeholders involved in these translation processes. We used the computerized version of the PolicyMaker political mapping tool to collect and organize important information about the pharmacogenomics and genomic medicine policy environment, serving as a database for assessments of the policy's content, the major players, their power and policy positions, their interests, and networks and coalitions that interconnect them. Our findings indicate that the genomic medicine policy environment in Greece seems to be rather positive, as the vast majority of the stakeholders express their medium to high support in the initially set goals of genomic medicine policy environment. The Ministry of Health and public healthcare insurance funds seem to oppose it, most likely due to financial constrains. These findings would contribute in selecting and implementing policy measures that will expedite the adoption of genomics into conventional medical interventions. © 2014 S. Karger AG, Basel.

  19. Desert dust outbreaks and respiratory morbidity in Athens, Greece. (United States)

    Trianti, Stavroula-Myrto; Samoli, Evangelia; Rodopoulou, Sophia; Katsouyanni, Klea; Papiris, Spyros A; Karakatsani, Anna


    Ambient particulate matter (PM) has an adverse effect on respiratory morbidity. Desert dust outbreaks contribute to increased PM levels but the toxicity of desert dust mixed with anthropogenic pollutants needs clarification. We identified 132 days with desert dust episodes and 177 matched days by day of the week, season, temperature and humidity between 2001 and 2006 in Athens, Greece. We collected data on regulated pollutants and daily emergency outpatient visits and admissions for respiratory causes. We applied Poisson regression models adjusting for confounding effects of seasonality, meteorology, holidays and influenza epidemics. We evaluated the sensitivity of our results to co-pollutant exposures and effect modification by age and sex. A 10 μg/m3 increase in PM10 concentration was associated with 1.95% (95% confidence interval (CI): 0.02%, 3.91%) increase in respiratory emergency room visits. No significant interaction with desert dust episodes was observed. Compared with non-dust days, there was a 47% (95% CI: 29%, 68%) increase in visits in dust days not adjusting for PM10. Desert dust days were associated with higher numbers of emergency room visits for asthma, chronic obstructive pulmonary disease and respiratory infections with increases of 38%, 57% and 60%, respectively (p desert dust days and were further confounded by co-pollutants. Desert dust episode days are associated with higher respiratory emergency room visits and hospital admissions. This effect is insufficiently explained by increased PM10 levels.

  20. Entertainment in View of Politicians in Ancient Greece and Rome

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    Valdas Pruskus


    Full Text Available The article discloses the cultural and social conditions of the entertainment phenomenon in Ancient Greece and Rome and the attitude of the authorities to it. The appearance of entertainment is closely related to the worship of cult of Gods. It is shown that the Romans being more materialistic and pragmatic paid less attention to spiritual entertainment than Greeks who fostered dramatic performances. Greek rulers and noblemen saw relaxational and educational function of the entertainment and also considered it as reducing tension and promoting solidarity. However, they did not intrude into its practical organization and had only a monitoring position, whereas the Romans were more interested in daily life and its bodily pleasures. Accordingly in recreational activities – games there dominated the spirit of competition, especially the gladiators games, which were bloody and cruel, but heated passions of spectators whose majority was comprised of plebs. There is shown that the authorities considered the entertainment as an effective tool to reach political aims, especially for gaining the support of commons in various elections, so they financed gladiators’ performances generously.This tradition is still topical in the flow of years. These days it has become the constituent part of the political marketing.

  1. Electronic Registry for the Management of Childhood Obesity in Greece. (United States)

    Kassari, Penio; Papaioannou, Panagiotis; Billiris, Antonis; Karanikas, Haralampos; Eleftheriou, Stergiani; Thireos, Eleftherios; Manios, Yannis; Chrousos, George P; Charmandari, Evangelia


    Obesity in childhood and adolescence represents a major health problem in our century. In Greece, more than 30-35% of children and adolescents are either overweight or obese. Using information and communication technologies, we developed a "National Registry for the Prevention and Management of Overweight and Obesity in Childhood and Adolescence" for guidance and training of Pediatricians and General Practitioners. The application supports interoperability with other national infrastructures and multi-layered security spanning preventive, detective and administrative controls. The Patient Summary dataset includes information on medical history, family history, medications, immunizations, clinical examination and laboratory findings, and appointment booking service. The application was launched in September 2015 and is accessible by: h t t p : //app.childhood-obesity. gr/. Based on the data that the doctor registers, the system calculates a personalized therapeutic algorithm that provides information on diet, physical exercise and sleep, as well as guidance on laboratory investigations and referral to specialized centres. A pilot study performed in 1,270 children and adolescents indicated that using this system resulted in a reduction of obesity rates by 30% and overweight rates by 35% within one year. This National eHealth System appears to be effective in the management of overweight and obesity in childhood and adolescence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Psychological distress, anxiety and depression among nursing students in Greece

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    Sapountzi-Krepia D.


    Full Text Available It is usually observed that nursing students undergo tremendous stress during various stages oftheir course but the knowledge about the stress process and depressive symptoms in this population is limited. TheAim of the present study was to determine the prevalence of psychological distress, anxiety and depression amongnursing students in Greece. For that purpose 170 nursing students (34 males, 136 females of the Department of Nursingof the Technological Educational Institute of Thessaloniki completed 3 self-report questionnaires, the General HealthQuestionnaire (GHQ, the Beck Depression Inventory II (BDI-II and the State-Trait Anxiety Inventory (STAI. The mean agewas 21.5 years. No difference in stress and depression on the basis of gender was observed. Our results showed that thescores on the GHQ, BDI and STAI tend to increase in the year 2 and 3. The majority of students reported relatively highscores on the GHQ suggesting increased psychiatric morbidity. 52.4% of students experienced depressive symptoms(34.7% mild, 12.9% moderate and 4.7% severe. The scores on the state scale were higher in the years 2 and 3, whilethe majority of students who had no or mild stress was observed in the first and the last year. Low stress personalitytraits were also observed in the first and the last year. However, no significant differences between the four years wereobserved. Our results suggest that nursing students experience different levels of stress and depression and that thesefactors are positively correlated.

  3. Estimating the Biogenic Non-Methane Hydrocarbon Emissions over Greece

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    Ermioni Dimitropoulou


    Full Text Available Biogenic emissions affect the urban air quality as they are ozone and secondary organic aerosol (SOA precursors and should be taken into account when applying photochemical pollution models. The present study presents an estimation of the magnitude of non-methane volatile organic compounds (BNMVOCs emitted by vegetation over Greece. The methodology is based on computation developed with the aid of a Geographic Information System (GIS and theoretical equations in order to produce an emission inventory on a 6 × 6 km2 spatial resolution, in a temporal resolution of 1 h covering one year (2016. For this purpose, a variety of input data was used: updated satellite land-use data, land-use specific emission potentials, foliar biomass densities, temperature, and solar radiation data. Hourly, daily, and annual isoprene, monoterpenes, and other volatile organic compounds (OVOCs were estimated. In the area under study, the annual biogenic emissions were estimated up to 472 kt, consisting of 46.6% isoprene, 28% monoterpenes, and 25.4% OVOCs. Results delineate an annual cycle with increasing values from March to April, while maximum emissions were observed from May to September, followed by a decrease from October to January.

  4. Essential-oil diversity of Salvia tomentosa Mill. in Greece. (United States)

    Hanlidou, Effie; Karousou, Regina; Lazari, Diamanto


    Salvia tomentosa essential oils from Greece were studied for the first time here. The oils from five populations growing in Mediterranean pine forests on the island of Thassos (northern Aegean Sea) and from 14 populations situated in deciduous forests in Thrace (northeastern Greek mainland) were investigated. Their essential-oil contents ranged from 1.1 to 3.3% (v/w, based on the dry weight of the plant material). The populations from Thassos had high contents of α-pinene (18.0 ± 2.9%), 1,8-cineole (14.7 ± 3.0%), cis-thujone (14.0 ± 6.9%), and borneol (12.8 ± 2.2%) and smaller amounts of camphene, camphor, and β-pinene, whereas the populations from Thrace showed high α-pinene (16.7 ± 4.0%), β-pinene (22.8 ± 4.5%), camphor (18.3 ± 4.3%), and camphene (10.3 ± 2.4%) contents, much lower 1,8-cineole and borneol amounts, while cis-thujone was completely lacking. The comparison of the present results with published data showed that oils having cis-thujone as one of the main compounds were reported for the first time here. Multivariate statistical analyses indicate that the observed essential-oil variation was related to geographical and environmental factors. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  5. Mercury in the Urban Topsoil of Athens, Greece

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    Efstratios Kelepertzis


    Full Text Available The present study documents the Hg content in 45 urban topsoil samples from the highly urbanized city of Athens, Greece. The Hg concentrations were quantified by applying aqua regia digestion on the <100 μm soil fraction followed by inductively coupled plasma-mass spectrometry (ICP-MS with a detection limit of 5 μg·kg−1. The median concentration of Hg in Athens soil is 96 μg·kg−1; ten out of 45 soil samples were found to contain Hg concentrations higher than 200 μg·kg−1, which is the maximum concentration value expected to be present in normal uncontaminated soils. Results obtained by multivariate principal component and hierarchical cluster analysis incorporating a large suite of chemical elements were notably effective for elucidating the anthropogenic origin of Hg in the studied soil. The elevated concentrations are most likely related to site-specific point source contamination rather than to the widely documented influences from the vehicular traffic emissions in urban settings. Given the proximity of urban population to the contaminated urban soils, we suggest the implementation of different soil extraction tests with the aim to evaluate the fraction of soil Hg available for absorption by the human body.


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    Stefania Andra SIMIONESCU


    Full Text Available The concept Yin-Yang represents the unity of opposites and complementarity. In this respect, from the economical point of view a positive Yin phase represents the cash flow, brings nutrition, gentleness and protection, while a negative Yin phase means capital loss, sloth and passive obedience, a positive Yang phase is translated as an action based on funds, emphasising the creation, the construction and the development of infrastructure thanks to an economical action plan, while a negative Yang phase leads to conflicts, to excessive product stocks and to a stock market collapse, causing, in this line, crisis and inflation by increasing prices and decreasing purchasing power. In the European Union, Greece faces a Yang negative phase. When having too much positive Yin monetary stimulus from the EU, the Yin-Yang balance turns in favour of a negative Yang bankrupcy and unemployment. Thus, I explore not only the Greece’s economical dimension, but also its geographic role, the synergy between culture and DNA and the last, but not the least, the human’s ability in creating a new positive Yin-Yang flourishing future.

  7. Parental attitudes towards head lice infestation in Greece. (United States)

    Doulgeraki, Artemis; Valari, Manthoula


    Pediculosis capitis constitutes a growing problem worldwide and is usually considered as an inconvenience. Parents often handle this infestation on their own initiative. We conducted a survey in order to depict the parental attitudes towards head lice infestation in Greece. Parents of children aged 3-14 years, attending a dermatology outpatient clinic at a children's hospital, were given a questionnaire regarding head lice. Demographic data, management, and prevention strategies were included in the questionnaire. Three-hundred and seventy-two complete questionnaires were analyzed (response rate: 89%). Pediculosis capitis was more prevalent in the age groups 3-5 years and 6-8 years. The percentage of parents of infested children who sought advice on treatment from the pharmacist was 73%, and only 15% consulted their doctor. Chemical agents to treat head lice were used by 59% of them, products containing natural oils by 38%, and wet combing in parallel was employed by 79% of them. Preventive measures were employed by 66% of the respondents, and 54% applied botanical and synthetic products commercially available for this purpose. There is a trend towards the use of natural oils for either prevention or treatment. More needs to be done to promote public education and rational use of either pediculicides or non-pharmacological agents for pediculosis capitis infestation. © 2011 The International Society of Dermatology.

  8. Screening for faecal contamination in primary schools in Crete, Greece. (United States)

    Kyriacou, A; Drakopoulou, S; Georgaki, I; Fountoulakis, M; Mitsou, E; Lasaridi, K E; Manios, Y; Manios, T


    Hygienic conditions in primary schools are a major concern for both governmental organizations and families. Particularly, the occurrence of faecal indicators on children's hands and various school surfaces has been associated with increased risk of diarrhoeal diseases. The presence of faecal streptococci on environmental surfaces and children's hands and the possible correlation with socio-economic factors were examined. Overall, 1956 samples from hands and 1470 samples from surfaces were collected from 20 primary schools in Heraklion, Crete, Greece. Faecal streptococci were found at 52.9% of children's hands and at 16.7% of other surfaces. Children, who had parents with the highest education level (>12 years), had the lowest percentage (48.8%) of faecal contamination on their hands. Furthermore, boys exhibited higher levels of hands contamination compared with girls. Among the environmental surfaces examined, the school canteen reception was the most contaminated area. High faecal contamination was detected in primary schools in the examined region. Children's hands were highly infected (52.9%), while boys exhibited higher levels of contamination. The educational level of parents correlated well with the contamination of children's hands.

  9. Resistant Shigella strains in refugees, August-October 2015, Greece. (United States)

    Georgakopoulou, T; Mandilara, G; Mellou, K; Tryfinopoulou, K; Chrisostomou, A; Lillakou, H; Hadjichristodoulou, C; Vatopoulos, A


    Shigellosis is endemic in most developing countries and thus a known risk in refugees and internally displaced persons. In 2015, a massive influx of refugees into Greece, due to the political crisis in the Middle East, led to the development of appropriate conditions for outbreaks of communicable diseases as shigellosis. We present a cluster of 16 shigellosis cases in refugees, detected by the implementation of a syndromic notification system in one transit centre in Athens, between 20 August and 7 October 2015. Both Shigella flexneri (n = 8) and S. sonnei (n = 8) were identified, distributed in various serotypes. All tested isolates (n = 13) were multidrug resistant; seven were CTX-M-type extended-spectrum β-lactamase producers. Our results indicate lack of a potential common source, although pulsed-field gel electrophoresis typing results revealed small clusters in isolates of the same serotype indicating possible limited person-to-person transmission without identifying secondary community cases related to the refugees. To prevent the spread of shigellosis, empirical antibiotic treatment as well as environmental hygiene measures were implemented. The detection of multi-drug resistance is important for determining the appropriate empirical antibiotic treatment for the more severe cases, while at the same time real-time typing is useful for epidemiological investigation and control measures.

  10. A Gastroenteritis Outbreak Caused by Noroviruses in Greece

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    Yiannis Alamanos


    Full Text Available In June 2006, an outbreak alert regarding cases of acute gastroenteritis in a region in North Eastern Greece (population 100,882 inhabitants, triggered investigations to guide control measures. The outbreak started the first days of June, and peaked in July. A descriptive epidemiological study, a virological characterization of the viral agent identified from cases as well as a phylogenetic analysis was performed. From June 5 to September 3, 2006 (weeks 23–44, 1,640 cases of gastroenteritis (45.2% male and 54.8% female, aged 3 months to 89 years were reported. The overall attack rate for the period was 16.3 cases/1,000 inhabitants. About 57% of cases observed were under the age of 15 years. Αnalysis of faecal samples identified Norovirus GII strains. Fifteen different Norovirus GII strains were recorded, presenting a homology of 94.8% (86–97% to GII strains obtained from GenBank. The long duration of the outbreak suggests an important role of person-to-person transmission, while the emergence of the outbreak was possibly due to contaminated potable water, although no viruses were detected in any tested water samples. This outbreak underscores the need for a national surveillance system for acute non-bacterial gastroenteritis outbreaks.

  11. The retail store managers' role: Evidence from Greece

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    Zairis, A.


    Full Text Available Despite the fact that the retail manager's role is determinant for a store's performance, and there is abundant wisdom about how to be an outstanding manager or what are the characteristics of a successful retail manager, there is no detailed description about the store managers' role or their actual work. Furthermore, the continuous developments in the retail sector have established different roles and created higher levels of responsibility for store managers. The aim of the present paper is to empirically investigate the role of retail store managers in Greece and identify any potential differences in terms of personal characteristics, tasks and various job-related factors. For the purposes of this research a survey was conducted focusing on the sectors of apparel/footwear and food, in an attempt to explore any potential differences within the two divisions. The results revealed the profile of the Greek store managers (male, over the age of 40, with a secondary level of education and more than five years of work experience and their multi-factor role. The three major roles that they perform were labeled as: sales oriented, supervisor, and customer experience oriented. The research also indicated that the two most popular sub-sectors in the Greek retail industry employ different profile managers. The issues of work experience, job satisfaction and security were also analysed.

  12. Temporal and spatial variability of rainfall over Greece (United States)

    Markonis, Y.; Batelis, S. C.; Dimakos, Y.; Moschou, E.; Koutsoyiannis, D.


    Recent studies have showed that there is a significant decrease in rainfall over Greece during the last half of the pervious century, following an overall decrease of the precipitation at the eastern Mediterranean. However, during the last decade an increase in rainfall was observed in most regions of the country, contrary to the general circulation climate models forecasts. An updated high-resolution dataset of monthly sums and annual daily maxima records derived from 136 stations during the period 1940-2012 allowed us to present some new evidence for the observed change and its statistical significance. The statistical framework used to determine the significance of the slopes in annual rain was not limited to the time independency assumption (Mann-Kendall test), but we also investigated the effect of short- and long-term persistence through Monte Carlo simulation. Our findings show that (a) change occurs in different scales; most regions show a decline since 1950, an increase since 1980 and remain stable during the last 15 years; (b) the significance of the observed decline is highly dependent to the statistical assumptions used; there are indications that the Mann-Kendall test may be the least suitable method; and (c) change in time is strongly linked with the change in space; for scales below 40 years, relatively close regions may develop even opposite trends, while in larger scales change is more uniform.

  13. Spatial and temporal variability of lightings over Greece (United States)

    Nastos, P. T.; Matsangouras, J. T.


    Lightings are the most powerful and spectacular natural phenomena in the lower atmosphere, being a major cause of storm related deaths. Cloud-to-ground lightning can kill and injure people by direct or indirect means. Lightning affects the many electrochemical systems in the body causing nerve damage, memory loss, personality change, and emotional problems. Besides, among the various nitrogen oxides sources, the contribution from lightning likely represents the largest uncertainty. In this study, the spatial and temporal variability of recorded lightings over Greece during the period from January 1, 2008 to December 31, 2009, were analyzed. The data for retrieving the location and time-of-occurrence of lightning were acquired from Hellenic National Meteorological Service (HNMS) archive dataset. An operational lighting detector network was established in 2007 by HNMS consisted of eight time-of-arrival sensors (TOA), spatially distributed across Greek territory. The spatial variability of lightings revealed their incidence within specific geographical sub-regions while the temporal variability concerning the seasonal, monthly and daily distributions resulted in better understanding of the time of lightings’ occurrence. All the analyses were carried out with respect to cloud to cloud, cloud to ground and ground to cloud lightings, within the examined time period.

  14. Obstacles to the Growth of Alternative Tourism in Greece

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    Athena Smith


    Full Text Available In the midst of the recent economic melt-down in Greece, economists are discussing the potential of tourism to pull the country out of its current woes. More than 16 million tourists visit the country annually whereas the sector contributes 15% to the nation's Gross Domestic Product and offers employment to 16% of the work force (Hellenic Statistical Authority, 2010. Concurrently, mass tourism has also caused a rise in pollution, a depletion of water supplies, desertification, rural emigration to urban centers, erosion of coastal areas and a drop in hygienic standards, all of which have had serious economic costs and caused residents to protest the industry’s mode of expansion. To that purpose, alternative types of tourism such as agrotourism and ecotourism have been defined as overarching objectives that complement the strategy for growth and employment. However, a closer look at the spots mostly known for alternative tourism activities shows the parallel emergence of other socio-economic developments that have slowly eroded Greek rural life and intensified the economic disparities between the local social classes. A closer evaluation of the damaging side effects casts doubt on the potential of alternative tourism as practiced today to inject growth into a stagnating economy.

  15. Breathing modes of Kolumbo submarine volcano (Santorini, Greece) (United States)

    Bakalis, Evangelos; Mertzimekis, Theo J.; Nomikou, Paraskevi; Zerbetto, Francesco


    Submarine volcanoes, such as Kolumbo (Santorini, Greece) are natural laboratories for fostering multidisciplinary studies. Their investigation requires the most innovative marine technology together with advanced data analysis. Conductivity and temperature of seawater were recorded directly above Kolumbo’s hydrothermal vent system. The respective time series have been analyzed in terms of non-equilibrium techniques. The energy dissipation of the volcanic activity is monitored by the temperature variations of seawater. The venting dynamics of chemical products is monitored by water conductivity. The analysis of the time series in terms of stochastic processes delivers scaling exponents with turning points between consecutive regimes for both conductivity and temperature. Changes of conductivity are shown to behave as a universal multifractal and their variance is subdiffusive as the scaling exponents indicate. Temperature is constant over volcanic rest periods and a universal multifractal behavior describes its changes in line with a subdiffusive character otherwise. The universal multifractal description illustrates the presence of non-conservative conductivity and temperature fields showing that the system never retains a real equilibrium state. The existence of a repeated pattern of the combined effect of both seawater and volcanic activity is predicted. The findings can shed light on the dynamics of chemical products emitted from the vents and point to the presence of underlying mechanisms that govern potentially hazardous, underwater volcanic environments.

  16. The market for reproductive tourism: an analysis with special reference to Greece. (United States)

    Paraskou, Anastasia; George, Babu P


    For many people, the need for parenthood remains unfulfilled due to biological reasons and a remedy for these individuals is assisted reproduction (AR). Because of widely differing and sometimes incompatible legislations around the world related to AR, there is considerable confusion across national borders. Within Europe, Greece seems to be in a comparatively favorable position because of lower restrictions and the availability of decent quality specialized medical facilities. This research is a market study with a business perspective and explores the emerging landscape of reproductive tourism (RT) in Greece. The research adopted mixed methods. First, open-ended questions were used to interview foreign medical tourists and staff in various AR clinics. Based on the insights from these interviews and guided by the extent literature, a survey instrument was prepared and administered among 130 patients. Findings indicate that Greece still lack policies that nurture transparency and dynamic response to technological changes in AR. Also, the travel industry lack specialists who can effectively liaison with clinics, who understand the availability of AR technologies, regulations, and the unique needs of AR tourists. Globally, the need for assisted reproduction has tremendously increased; yet, the supply of facilities is lagging far behind. There is a unique advantage for clinics located in touristic locations in countries that offer cheaper treatment options. Given the shape of its debt-ridden economy, Greece needs foreign exchange inflows and gaining first mover advantage in reproductive tourism is probably an important way to achieve this. This research draws up a reproductive tourism strategy for Greece.

  17. Subsidence history, crustal structure and evolution of the Nogal Rift, Northern Somalia (United States)

    Ali, M. Y.; Watts, A. B.


    Seismic reflection profile, gravity anomaly, and biostratigraphic data from deep exploration wells have been used to determine the tectonic subsidence, structure and evolution of the Nogal basin, Northern Somalia, one of a number of ENE-WSW trending early Mesozoic rifts that formed prior to opening of the Gulf of Aden. Backstripping of biostratigraphic data at the Nogal-1 and Kali-1 wells provides new constraints on the age of rifting, and the amount of crustal and mantle extension. The tectonic subsidence and uplift history at the wells can be generally explained as a consequence of two, possibly three, major rifting events. The first event initiated in the Late Jurassic (~156 Ma) and lasted for ~10 Myr. We interpret the rift as a late stage event associated with the break-up of Gondwana and the separation of Africa and Madagascar. The second event initiated in the Late Cretaceous (~80 Ma) and lasted for ~20 Myr. This event probably correlates with a rapid increase in spreading rate on the ridges separating the African and Indian and African and Antarctica plates and a contemporaneous slowing down of Africa's plate motion. The backstripped tectonic subsidence data can be explained by a multi-rift extensional model with a stretching factor, β, in the range 1.17-1.38. The third and most recent event occurred in the Oligocene (~32 Ma) and lasted for ~10 Myr. This rift only developed at the centre of the basin close to Nogal-1 well, and is related to the opening of the Gulf of Aden. The amount of crustal thinning inferred at the Kali-1 well is consistent with the results of Process-Oriented Gravity and Flexure (POGM) modelling, assuming an elastic thickness of ~30 km. The thinning at the Nogal-1 well, however, is greater by ~ 7 km than predicted suggesting that the basin may be locally underplated by magmatic material. Irrespective, POGM suggests the transition between thick crust beneath Northern Somalia to thin crust beneath the Indian Ocean forms a ~500 km wide

  18. Transect across the West Antarctic rift system in the Ross Sea, Antarctica (United States)

    Trey, H.; Cooper, A. K.; Pellis, G.; Della, Vedova B.; Cochrane, G.; Brancolini, Giuliano; Makris, J.


    In 1994, the ACRUP (Antarctic Crustal Profile) project recorded a 670-km-long geophysical transect across the southern Ross Sea to study the velocity and density structure of the crust and uppermost mantle of the West Antarctic rift system. Ray-trace modeling of P- and S-waves recorded on 47 ocean bottom seismograph (OBS) records, with strong seismic arrivals from airgun shots to distances of up to 120 km, show that crustal velocities and geometries vary significantly along the transect. The three major sedimentary basins (early-rift grabens), the Victoria Land Basin, the Central Trough and the Eastern Basin are underlain by highly extended crust and shallow mantle (minimum depth of about 16 km). Beneath the adjacent basement highs, Coulman High and Central High, Moho deepens, and lies at a depth of 21 and 24 km, respectively. Crustal layers have P-wave velocities that range from 5.8 to 7.0 km/s and S-wave velocities from 3.6 to 4.2 km/s. A distinct reflection (PiP) is observed on numerous OBS from an intra-crustal boundary between the upper and lower crust at a depth of about 10 to 12 km. Local zones of high velocities and inferred high densities are observed and modeled in the crust under the axes of the three major sedimentary basins. These zones, which are also marked by positive gravity anomalies, may be places where mafic dikes and sills pervade the crust. We postulate that there has been differential crustal extension across the West Antarctic rift system, with greatest extension beneath the early-rift grabens. The large amount of crustal stretching below the major rift basins may reflect the existence of deep crustal suture zones which initiated in an early stage of the rifting, defined areas of crustal weakness and thereby enhanced stress focussing followed by intense crustal thinning in these areas. The ACRUP data are consistent with the prior concept that most extension and basin down-faulting occurred in the Ross Sea during late Mesozoic time, with

  19. Asymmetric rifting and structures of conjugated margins in the Tyrrhenian Sea (United States)

    Moeller, S.; Grevemeyer, I.; Berndt, C.; Klaeschen, D.; Ranero, C. R.; Sallares, V.; Zitellini, N.


    Stretching and thinning of the continental lithosphere leads to rifting and the formation of passive continental margins. However, there is a discrepancy between horizontal extension by faulting and vertical crustal thinning. Research is ongoing to investigate this relationship. The Tyrrhenian Sea is a young rift basin of Neogene age located in the Western Mediterranean. Here, it is assumed that rifting and opening of the basin commenced in the context of slab rollback during the closing of the Tethys oceanic lithosphere. The advantages of studying rift processes here are the conjugated margins which are very close to each other. We present results of an integrated reflection (MCS) and refraction/wide-angle seismic (WAS) profile crossing the North Tyrrhenian Sea along 41° N. The data of the 240 km geophysical profile were acquired in April and May of 2010 during the MEDOC-Cruise in a two-ship operation with the Spanish and Italian vessels Sarmiento de Gamboa and Urania. The basin is characterized by N-S elongated horst and graben structures indicating that the rifting occured in W-E direction. The depth-migrated MCS section shows a detailed image of the infill of these grabens and reveals buried blocks, normal listric faults and smaller detachments in the brittle upper crust to a depth of 5-6 km. Integrating drilling information of ODP leg 107, we identified Messinian synrift and Plio/Pleistocene postrift sediments to derive the chronological development of the Tyrrhenian Sea. The deep and thick Messinian evaporites near the Sardinian continental margin support the idea that this area marks the origin of rifting, subsidence and initial flooding. A comparison of crustal structures between the Sardinian and Campanian margins reveals significant differences in block size and in sedimentary thickness, which decreases from west to east. The horizontal extension in the West was accommodated by the formation of large horst and graben structures while extension in the

  20. Asymmetric rifting, breakup and magmatism across conjugate margin pairs: insights from Newfoundland to Ireland (United States)

    Peace, Alexander L.; Welford, J. Kim; Foulger, Gillian R.; McCaffrey, Ken J. W.


    Continental extension, subsequent rifting and eventual breakup result in the development of passive margins with transitional crust between extended continental crust and newly created oceanic crust. Globally, passive margins are typically classified as either magma-rich or magma-poor. Despite this simple classification, magma-poor margins like the West Orphan Basin, offshore Newfoundland, do exhibit some evidence of localized magmatism, as magmatism to some extent invariably accompanies all continental breakup. For example, on the Newfoundland margin, a small volcanic province has been interpreted near the termination of the Charlie Gibbs Fracture Zone, whereas on the conjugate Irish margin within the Rockall Basin, magmatism appears to be more widespread and has been documented both in the north and in the south. The broader region over which volcanism has been identified on the Irish margin is suggestive of magmatic asymmetry across this conjugate margin pair and this may have direct implications for the mechanisms governing the nature of rifting and breakup. Possible causes of the magmatic asymmetry include asymmetric rifting (simple shear), post-breakup thermal anomalies in the mantle, or pre-existing compositional zones in the crust that predispose one of the margins to more melting than its conjugate. A greater understanding of the mechanisms leading to conjugate margin asymmetry will enhance our fundamental understanding of rifting processes and will also reduce hydrocarbon exploration risk by better characterizing the structural and thermal evolution of hydrocarbon bearing basins on magma-poor margins where evidence of localized magmatism exists. Here, the latest results of a conjugate margin study of the Newfoundland-Ireland pair utilizing seismic interpretation integrated with other geological and geophysical datasets are presented. Our analysis has begun to reveal the nature and timing of rift-related magmatism and the degree to which magmatic asymmetry

  1. Internal Structure of the Extinct Skagi-Hunafloi Rift Zone and Implications for Magmatic Construction (United States)

    Siler, D. L.; Karson, J. A.; Varga, R. J.; Horst, A. J.


    Structural relief ~1.5 km of basaltic crust on the eastern flank of the now-extinct Skagi-Hunafloi rift zone (active between 8 and 4 Ma) is exposed in two mountain ranges bounding the glacially excavated Vatnsdalur in northwestern Iceland. This area reveals both the along- and across-strike variations within an abandoned Tertiary rift zone. Regionally the rift zone is characterized by a "flexure zone" with basaltic lavas that dip 5-10° westward, toward the rift axis. Superimposed on this structure is a bowl-shaped depression at least 800 m deep and ~5 km in diameter in which lava flows dip as much as 50° inward. The lowest package of lavas associated with the depression are basaltic and minor rhyolitic flows (7.62±0.32 Ma), which are at least 400 m thick and have been tectonically rotated during subsidence, as indicated by field relationships and preliminary paleomagnetic data. Overlying these tilted, pre-subsidence flows are syn-subsidence basaltic lavas, which are at least 150 m thick and breccias all of which thicken toward the center of the depression. Overlying the syn- subsidence flows is a ~250 m thick basaltic lens (6.98±0.32 Ma). Ages and thicknesses of units associated with the depression roughly constrain the local subsidence rates at ~1 km/my. Just to the west, gabbroic to granophyric intrusions and hydrothermally altered igneous rocks and breccias mark a dissected volcanic center. Dense (cone?) sheet swarms dip radially inward. This entire assemblage is overlain by gently dipping basaltic to rhyolitic lavas showing that magmatic construction did not result in generation of high relief. Crustal thickening was accommodated by subsidence and backfilling near the depression and by basaltic to minor rhyolitic sheet intrusions over a broader surrounding area. Folding of the pre-subsidence lavas was likely accommodated by slip on steeply dipping fractures and within flow top breccia units. Focused subaxial subsidence in rift zones may result from

  2. Monitoring recent crustal movements in the Kenya rift valley by global positioning system (GPS) — a proposal (United States)

    Rostom, R. S.

    There is evidence that the Kenya Rift is active. 1990 witnessed the execution of the Kenya Rift International Seismic Project to study the deep structure of the Kenya Rift. Yet there is no actual measurement of the rate of its spreading. Estimation based on volumes of volcanic rocks extruded over a given period has led to a wide range of estimates (0.2-2 mm/a). There is a need to establish geometrically the real spreading rate at present. The new technology (Global Positioning System) in its precise mode gives a promise to solve the problem. A preliminary network is proposed to consist of 4 points on each of the Rift walls. The logistics of site location, configuration of the network, observation method, frequency, etc. are discussed. The project requires international cooperation for execution.

  3. A Hierarchical Network Approach for Modeling Rift Valley Fever Epidemics with Applications in North America: e62049

    National Research Council Canada - National Science Library

    Ling Xue; Lee W Cohnstaedt; H Morgan Scott; Caterina Scoglio


    .... In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors...

  4. Comparison of the rift and post-rift architecture of conjugated salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic (United States)

    Strozyk, Frank; Back, Stefan; Kukla, Peter A.


    This study presents a regional comparison between selected 2D seismic transects from large, conjugated salt and salt-free basins offshore southern Brazil (Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Kwanza Basin, northern and southern Namibe Basin, Walvis Basin). Tectonic-stratigraphic interpretation of the main rift and post-rift units, free-air gravity data and flexural isostatic backstripping were used for a comprehensive basin-to-basin documentation of key mechanisms controlling the present-day differences in conjugated and neighbouring South Atlantic basins. A significant variation in the tectonic-sedimentary architecture along-strike at each margin and between the conjugated basins across the South Atlantic reflects major differences in (1) the structural configuration of each margin segment at transitional phase between rifting and breakup, as emphasized in the highly asymmetric settings of the large Santos salt basin and the conjugated, salt-free southern Namibe Basin, (2) the post-breakup subsidence and uplift history of the respective margin segment, which caused major differences for example between the Campos and Espirito Santo basins and the conjugated northern Namibe and Kwanza basins, (3) variations in the quantity and distribution of post-breakup margin sediments, which led to major differences in the subsidence history and the related present-day basin architecture, for example in the initially rather symmetric, siliciclastic Pelotas and Walvis basins, and (4) the deposition of Aptian evaporites in the large rift and sag basin provinces north of the Rio Grande Rise and Walvis Ridge, highly contrasting the siliciclastic basins along the margin segments south of the ridges. The resulting present-day architecture of the basins can be generally classified as (i) moderately symmetric, salt-free, and magma-rich in the northern part of the southern segment, (i) highly asymmetric, salt-bearing and magma-poor vs. salt-free and magma

  5. Seismic hazard assessment of the Kivu rift segment based on a new sismo-tectonic zonation model (Western Branch of the East African Rift system) (United States)

    Havenith, Hans-Balder; Delvaux, Damien


    In the frame of the Belgian GeoRisCA multi-risk assessment project focused on the Kivu and Northern Tanganyika Region, a seismic hazard map has been produced for this area. It is based on a on a recently re-compiled catalogue using various local and global earthquake catalogues. The use of macroseismic epicenters determined from felt earthquakes allowed to extend the time-range back to the beginning of the 20th century, thus spanning about 100 years. The magnitudes have been homogenized to Mw and the coherence of the catalogue has been checked and validated. The seismo-tectonic zonation includes 10 seismic source areas that have been defined on the basis of the regional geological structure, neotectonic fault systems, basin architecture and distribution of earthquake epicenters. The seismic catalogue was filtered by removing obvious aftershocks and Gutenberg-Richter Laws were determined for each zone. On the basis of this seismo-tectonic information and existing attenuation laws that had been established by Twesigomwe (1997) and Mavonga et al. (2007) for this area, seismic hazard has been computed with the Crisis 2012 (Ordaz et al., 2012) software. The outputs of this assessment clearly show higher PGA values (for 475 years return period) along the Rift than the previous estimates by Twesigomwe (1997) and Mavonga (2007) while the same attenuation laws had been used. The main reason for these higher PGA values is likely to be related to the more detailed zonation of the Rift structure marked by a strong gradient of the seismicity from outside the rift zone to the inside. Mavonga, T. (2007). An estimate of the attenuation relationship for the strong ground motion in the Kivu Province, Western Rift Valley of Africa. Physics of the Earth and Planetary Interiors 62, 13-21. Ordaz M, Martinelli F, Aguilar A, Arboleda J, Meletti C, D'Amico V. (2012). CRISIS 2012, Program for computing seismic hazard. Instituto de Ingeniería, Universidad Nacional Autónoma de M

  6. Is There a Need for a Higher Dance Institution in Greece? The Reality in Greek Contemporary Dance Institutions (United States)

    Tsompanaki, Eleni


    Is there a need for dance to enter higher education in Greece? Can contemporary dance be viewed as a discipline on its own right? These questions inspired the research conducted in three case study institutions (out of six that exist) in Greece, examining the reality within them as experienced by dance students, lecturers, course leaders and the…

  7. Thermo-mechanical modeling of continental rift evolution over mantle upwelling in presence of far-field stresses (United States)

    Koptev, Alexander; Burov, Evgueni; Calais, Eric; Leroy, Sylvie; Gerya, Taras


    We conducted fully-coupled high resolution rheologically consistent 3D thermo-mechanical numerical models to investigate the processes of mantle-lithosphere interaction (MLI) in presence of preexisting far-field tectonic stresses. MLI-induced topography exhibits strongly asymmetric small-scale 3D features, such as rifts, flexural flank uplifts and complex faults structures. This suggests a dominant role of continental rheological structure and intra-plate stresses in controlling continental rifting and break-up processes above mantle upwelling while reconciling the passive (far-field tectonic stresses) versus active (plume-activated) rift concepts as our experiments show both processes in action. We tested different experiments by varying two principal controlling parameters: 1) horizontal extension velocity and 2) Moho temperature used as simplified indicator of the thermal and rheological lithosphere layering. An increase in the applied extension expectedly gives less localized deformation at lithospheric scale: the growth of external velocity from 1.5 mm/years to 6 mm/years leads to enlargement of the rift zones from 75-175 km to 150-425 km width. On the contrary, increasing of the lithospheric geotherm has an opposite effect leading to narrowing of the rift zone: the change of the Moho isotherm from 600°C to 800°C causes diminution of the rift width from 175-425 km to 75-150 km. Some of these finding are contra-intuitive in terms of usual assumptions. The models refer to strongly non-linear impact of far-field extension rates on timing of break-up processes. Experiments with relatively fast far-field extension (6 mm/years) show intensive normal fault localization in crust and uppermost mantle above the plume head at 15-20 Myrs after the onset of the experiment. When plume head material reaches the bottom of the continental crust (at 25 Myrs), the latter is rapidly ruptured (break-up time (from 60 to 70 Myrs depending on initial isotherm at the crust bottom

  8. Aigion Fault seismogenic behaviour and future drilling plans (United States)

    Cornet, Fh.; Boulhaia, W.; Mendel, V.


    The Corinth Rift Zone, in western central Greece, is one of the most seismogenic regions in Europe, with four earthquakes with magnitude larger than 6 during the last thirty years. An intense seismic activity is observed near the city of Aigion, about 20 km far from the western rift extremity, with three 6 to 8 months long seismic swarms over the last eight years. A 1000 m deep well intersects the 60 ° north dipping Aigion Fault, at a depth of 760 m and was instrumented with four high frequency (2.5 KHz) sensors (two geophones at 750 m and two hydrophones located respectively at 500 m and 250 m). The sensors have recorded both the seismic events from the rift activity at depths ranging from 6 to 8 km, and high frequency short duration events that seem to be located within less than 1 km from the deepest sensor. These short duration events suggest that the Aigion fault is creeping in its upper 2 km but becomes progressively seismogenic with depth. In particular it has been the site of magnitude 2 earthquakes during the 2003-2004 swarm crisis. A proposal is being prepared to intersect the fault below the detachment zone at the base of Gavrovo-Tripolitza nappe, so as to document the seismogenic characteristics of the fault, its relationship with the local rift opening process and its influence on regional fluid fluxes. This ICDP drilling proposal is complementary to the IODP proposal for a multi-hole investigation in both recent soft sediments and basement rocks. The objective is to constrain the Rifting process but may reveal unique for documenting climate changes over the last million years.

  9. Basement - Cover decoupling and progressive exhumation of metamorphic sediments at hot rifted margin. Insights from the Northeastern Pyrenean analog (United States)

    Clerc, Camille; Lagabrielle, Yves; Labaume, Pierre; Ringenbach, Jean-Claude; Vauchez, Alain; Nalpas, Thierry; Bousquet, Romain; Ballard, Jean-François; Lahfid, Abdeltif; Fourcade, Serge


    We compile field data collected along the eastern part of the North Pyrenean Zone (NPZ) to point to a tectonic evolution under peculiar thermal conditions applying to the basin sediments in relation with the opening of the Cretaceous Pyrenean rift. Based on this compilation, we show that when thinning of the continental crust increased, isotherms moved closer to the surface with the result that the brittle-ductile transition propagated upward and reached sediments deposited at the early stage of the basin opening. During the continental breakup, the pre-rift Mesozoic cover was efficiently decoupled from the Paleozoic basement along the Triassic evaporite level and underwent drastic ductile thinning and boudinage. We suggest that the upper Albian and upper Cretaceous flysches acted as a blanket allowing temperature increase in the mobile pre-rift cover. Finally, we show that continuous spreading of the basin floor triggered the exhumation of the metamorphic, ductily sheared pre-rift cover, thus contributing to the progressive thinning of the sedimentary pile. In a second step, we investigate the detailed geological records of such a hot regime evolution along a reference-section of the eastern NPZ. We propose a balanced restoration from the Mouthoumet basement massif (north) to the Boucheville Albian basin (south). This section shows a north to south increase in the HT Pyrenean imprint from almost no metamorphic recrystallization to more than 600 °C in the pre- and syn-rift sediments. From this reconstruction, we propose a scenario of tectonic thinning involving the exhumation of the pre-rift cover by the activation of various detachment surfaces at different levels in the sedimentary pile. In a third step, examination of the architecture of current distal passive margin domains provides confident comparison between the Pyrenean case and modern analogs. Finally, we propose a general evolutionary model for the pre-rift sequence of the Northeastern Pyrenean rifted

  10. Seroprevalence of Sheep and Goat Pox, Peste Des Petits Ruminants and Rift Valley Fever in Saudi Arabia


    Hani Boshra; Thang Truong; Shawn Babiuk; Maged Gomaa Hemida


    Sheep and goat pox, peste des petits ruminants and Rift Valley fever are important diseases of small ruminant livestock. Sheep and goat pox, along with peste des petits ruminants, are endemic throughout most of Africa, Asia and the Middle East. Whereas Rift Valley fever is endemic in Africa, outbreaks in the Middle East have been reported over the past decade, including the Arabian Peninsula. Saudi Arabia is a major importer of livestock, and understanding the prevalence of these viral infect...

  11. Evolution of the broadly rifted zone in southern Ethiopia through gravitational collapse and extension of dynamic topography (United States)

    Emishaw, Luelseged; Laó-Dávila, Daniel A.; Abdelsalam, Mohamed G.; Atekwana, Estella A.; Gao, Stephen S.


    The Broadly Rifted Zone (BRZ) is a 315 km wide zone of extension in southern Ethiopia. It is located between the Southern Main Ethiopian Rift and the Eastern Branch of the East African Rift System (EARS) represented by the Kenya-Turkana Rift. The BRZ is characterized by NE-trending ridges and valleys superimposed on regionally uplifted ( 2 km average elevation) terrain. Previous studies proposed that the BRZ is an overlap zone resulted from northward propagation of the Kenya-Turkana Rift and southward propagation of the Southern Main Ethiopian Rift. To understand the relationship between the BRZ's extensional style and its crustal and upper mantle structures, this work first estimated the Moho depth using the two-dimensional (2D) radially-averaged power spectral analysis of the World Gravity Map. Verification of these results was accomplished through lithospheric-scale 2D forward gravity models along E-W profiles. This work found that the Moho topography beneath the BRZ depicts a dome-like shape with a minimum depth of 27 km in the center of the dome. This work proposes that the Moho doming, crustal arching underlying the BRZ and associated topographic uplift are the result of asthenospheric mantle upwelling beneath the BRZ. This upwelling changed to a NE-directed lateral mantle flow at shallower depth. This is supported by seismic tomography imaging which shows slow S-wave velocity anomaly at lithospheric depth of 75 km to 150 km stretching in a NE-SW direction from beneath the BRZ to the Afar Depression. This work proposes that the asthenospheric upwelling created gravitationally unstable dynamic topography that triggered extensional gravitational collapse leading to the formation of the BRZ as a wide rift within the narrow rift segments of the EARS.

  12. Government Debt Reduction in the USA and Greece: A Comparative VECM Analysis

    Directory of Open Access Journals (Sweden)

    Gisele MAH


    Full Text Available The purpose of this paper is to estimate comparative debt reduction models for the USA and Greece using Vector Error Correction Model analysis and Granger causality test. The study provides an empirical framework that could assist in policy formulation for countries with high debt rates as well as those experiencing debt crises. The US model revealed a negative and significant relationship between general government debt and inflation as well as negative significance with primary balance. In Greece, the relationship between general government debts with primary balance is found to be positive and significant while negative and significant with net transfer from abroad. Granger causality is from general government debts to inflation in the USA and from primary balance to general government debts in Greece.

  13. Detection of Dirofilaria immitis in a brown bear (Ursus arctos in Greece

    Directory of Open Access Journals (Sweden)

    Papadopoulos E.


    Full Text Available Dirofilaria immitis (canine heartworm is a filarial nematode found in the pulmonary circulation and the heart of susceptible hosts. It represents an important zoonotic vector-borne disease of domestic dogs and several wildlife species. Herein we report for the first time, the finding of Dirofilaria immitis worms in a brown bear killed in a vehicle collision in Northern Greece. The worms were morphologically identified; molecular examination, based on the analysis of the mitochondrial genes 12S (433 bp and CO1 (610 bp, verified the identification by demonstrating 100% similarity to D. immitis specimens deposited in GenBank. Brown bears in Greece occupy habitats that are shared with the potential wild and domestic hosts and the vectors of D. immitis and thus may be particularly susceptible to this parasite. This report contributes to the knowledge of dirofilariosis spread in Europe and on the epidemiological threats that may affect the survival of the endangered brown bear in Greece.

  14. Constructed wetlands for wastewater and activated sludge treatment in north Greece: a review. (United States)

    Tsihrintzis, V A; Gikas, G D


    Constructed wetlands used for the treatment of urban, industrial and agricultural wastewater have become very popular treatment systems all over the world. In Greece, these systems are not very common, although the climate is favourable for their use. During recent years, there have been several attempts for the implementation of these systems in Greece, which include, among others, pilot-scale systems used for research, and full-scale systems designed and/or constructed to serve settlements or families. The purpose of this paper is the presentation of systems operating in Northern Greece, which have been studied by the Laboratory of Ecological Engineering and Technology of Democritus University of Thrace and others. A comparison is made of different system types, and the effect of various design and operational parameters is presented. Current research shows the good and continuous performance of these systems.

  15. Check list and zoogeographic analysis of the scale insect fauna (Hemiptera: Coccomorpha) of Greece. (United States)

    Pellizzari, Giuseppina; Chadzidimitriou, Evangelia; Milonas, Panagiotis; Stathas, George J; Kozár, Ferenc


    This paper presents an updated checklist of the Greek scale insect fauna and the results of the first zoogeographic analysis of the Greek scale insect fauna. According to the latest data, the scale insect fauna of the whole Greek territory includes 207 species; of which 187 species are recorded from mainland Greece and the minor islands, whereas only 87 species are known from Crete. The most rich families are the Diaspididae (with 86 species), followed by Coccidae (with 35 species) and Pseudococcidae (with 34 species). In this study the results of a zoogeographic analysis of scale insect fauna from mainland Greece and Crete are also presented. Five species, four from mainland Greece and one from Crete are considered to be endemic. Comparison with the scale insect fauna of other countries is provided.

  16. Distribution of nontuberculous mycobacteria in treated patients with pulmonary disease in Greece - relation to microbiological data. (United States)

    Manika, Katerina; Tsikrika, Stamatoula; Tsaroucha, Emilia; Karabela, Simona; Karachaliou, Iris; Bosmi, Ioulia; Kioumis, Ioannis; Papavasileiou, Apostolos


    The aim was to assess the distribution of nontuberculous mycobacteria (NTM) in treated patients with pulmonary disease (PD) in Greece. Patients treated for NTM PD at the two largest chest diseases hospitals in Greece, in the period 1990-2013 were investigated. For the years 2005-2013 data on NTM isolation frequency were recorded. M. avium complex (MAC) was the predominant cause of NTM PD disease followed by M. kansasii and rapid growing mycobacteria (RGM). The pathogenicity of RGM was significantly lower than this of MAC and M. kansasii. An increase was observed in the percentage of isolated NTM species that were considered clinically significant over the study period. The increasing number of NTM PD in Greece is a consequence of their isolation being more frequently considered as clinically relevant.

  17. Oxidative Potential of ambient particulate matter in Athens, Greece. (United States)

    Paraskevopoulou, Despina; Bougiatioti, Aikaterini; Fang, Ting; Liakakou, Eleni; Weber, Rodney; Nenes, Athanasios; Mihalopoulos, Nikolaos


    Exposure of populations to airborne particulate matter (PM) is a leading cause of premature death worldwide. Oxidative stress resulting from exposure of chemical species present in PM is a mechanism thought to cause adverse health effects. Apart from radicals present in aerosol, species that can catalytically deplete the antioxidant buffering capacity of cells, called Oxidative Potential (OP), are thought to be particularly toxic. The variability of OP over location, particle age, source and environmental conditions is virtually unknown for most populated regions of the world. Motivated by this, we have built and deployed one of the first operational measurements of OP in Europe at the National Observatory of Athens site in downtown Athens, Greece. OP for fine and coarse mode is measured using a semi-automated dithiothreitol (DTT) assay developed at the Georgia Institute of Technology; the assay measures the oxidation rate of DTT by water-soluble aerosol constituents, and simulates the rate at which the same compounds would deplete antioxidants in-vivo. The DTT oxidation rate per unit volume of air (water-soluble "DTT activity") and aerosol size class (fine, coarse) are used as a measure of aerosol toxicity. We present continuous (24hr average) OP measurements in downtown Athens from July 2016 to January 2017, conducted through quartz fiber filter analysis. The dataset covers a broad range of aerosol sources (pollution from Europe, regional and local biomass burning, dust, marine aerosol, biogenic aerosol) and meteorological conditions. The daily water-soluble DTT activity ranges between 0.02-0.81 nmolmin-1 m-3 (averaging at 0.24 nmolmin-1 m-3) for fine aerosol and between 0.01-0.52 nmolmin-1 m-3 (averaging at 0.08 nmolmin-1 m-3) for coarse particulate matter, indicating that water-soluble fine mode aerosol components possess a significant fraction of the OP. The seasonal variability demonstrates a higher DTT activity during the coldest period of the year for both

  18. History of the development of the East African Rift System: A series of interpreted maps through time (United States)

    Macgregor, Duncan


    This review paper presents a series of time reconstruction maps of the 'East African Rift System' ('EARS'), illustrating the progressive development of fault trends, subsidence, volcanism and topography. These maps build on previous basin specific interpretations and integrate released data from recent petroleum drilling. N-S trending EARS rifting commenced in the petroliferous South Lokichar Basin of northern Kenya in the Late Eocene to Oligocene, though there seem to be few further deep rifts of this age other than those immediately adjoining it. At various times during the Mid-Late Miocene, a series of small rifts and depressions formed between Ethiopia and Malawi, heralding the main regional rift subsidence phase and further rift propagation in the Plio-Pleistocene. A wide variation is thus seen in the ages of initiation of EARS basins, though the majority of fault activity, structural growth, subsidence, and associated uplift of East Africa seem to have occurred in the last 5-9 Ma, and particularly in the last 1-2 Ma. These perceptions are key to our understanding of the influence of the diverse tectonic histories on the petroleum prospectivity of undrilled basins.

  19. The distribution and hydrogeological controls of fluoride in the groundwater of central Ethiopian rift and adjacent highlands (United States)

    Ayenew, Tenalem


    Occurrence of fluoride (F) in groundwater has drawn worldwide attention, since it has considerable impact on human health. In Ethiopia high concentrations of F in groundwaters used for community water supply have resulted in extensive dental and skeletal fluorosis. As a part of a broader study, the distribution of F in groundwater has been investigated, and compared with bedrock geology and pertinent hydrochemical variables. The result indicates extreme spatial variations. High F concentration is often associated with active and sub-active regional thermal fields and acidic volcanics within high temperature rift floor. Variations in F can also be related to changes in calcium concentration resulting from dissolution of calcium minerals and mixing with waters of different chemical composition originated from variable hydrogeological environment across the rift valley. The concentration of F dramatically declines from the rift towards the highlands with the exception of scattered points associated with thermal springs confined in local volcanic centers. There are also interactions of F-rich alkaline lakes and the surrounding groundwater. Meteoric waters recharging volcanic aquifers become enriched with respect to F along the groundwater flow path from highland recharge areas to rift discharge areas. Locally wells drilled along large rift faults acting as conduits of fresh highland waters show relatively lower F. These areas are likely to be possible sources of better quality waters within the rift. The result of this study has important implications on site selection for water well drilling.

  20. Allergic conjunctivitis and the most common allergens in Northern Greece (United States)


    Background Ocular allergies affect a great part of the general population and often co exist with other allergic manifestations. In the present study, the prevalence of allergic conjunctivitis and the commonest allergens in allergic patients at an outpatient unit in Thessaloniki, Greece were evaluated. Methods This is a retrospective study regarding allergic patients who referred to an outpatient clinic between the 1st of January of 1996 and the 31st of December 2010. They completed relative questionnaires concerning their allergic condition. The patients who were included in our study had allergic conjunctivitis confirmed by ophthalmologists and were divided into 4 groups. The criteria used were the existence of allergic conjunctivitis alone or with other allergic co- morbidities. The patients then underwent skin prick tests after consent according to current guidelines. Results The archives of 1239 allergic patients were evaluated and 497 patients (40,11%) who manifested eye allergic symptoms were included in our study. 448 patients (90.14%) had allergic conjunctivitis in conjunction with asthma or rhinitis or both. 370 patients underwent skin prick tests and 284 of them (124 males-160 females) were positive for at least 1 of the 8 tested allergens (76.75%). 166 were positive to a grass mix (58.45%), 130 to olea European (45.77%), 124 to dust mites mix (43.66%), 58 to cypress (20.42%), 71 to parietaria officinalis (25.00%), 67 to cat dander (23.59%), 35 to dog dander (12.32%) and 32 to Altenaria (11.26%). Conclusions Symptoms of ocular allergy are very common in patients with allergic rhinitis and asthma. Men had slightly higher percentages of positive skin prick tests, except for dog dander and Altenaria. Conjunctivitis should not be overlooked as an allergic entity when evaluating allergic patients. PMID:23866689