WorldWideScience

Sample records for aegean sea ecohydrodynamics

  1. Offshore wind power in the Aegean Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Hahmann, Andrea N.

    The wind climate of the Mediterranean Sea has been estimated from atmospheric modelling (Cavaleri 2005, Lavignini et al. 2006) and QuikSCAT (Furevik et al. 2011). The latter shows the Aegean Sea as a promising area for offshore wind power development. According to the Hellenic Wind Energy...... Association (HWEA), the sites of particular interest for offshore wind energy are located close to the mainland and islands in the Aegean Sea. Wind farm developers aim to select local areas with favorable wind conditions to optimize the annual energy production and the economic profit. In the Aegean Sea...... winds (SDW). It is planned to combine the Envisat wind fields with Sentinel-1a and Sentinel-1b wind fields to further detail the offshore wind resource within the New European Wind Atlas. The work is in progress. Sentinel-1a images are processed at DTU Wind Energy near-real-time and we are updating our...

  2. Source of Aegean Sea harbour porpoises

    DEFF Research Database (Denmark)

    Lockyer, Christina; Rosel, P. E.; Frantzis, A.

    2003-01-01

    Documented sightings of harbour porpoises in the Mediterranean are rare, although the species is common in the neighbouring North Atlantic and Black Sea. However, in the past 2 decades, 4 harbour porpoises Phocoena phocoena have been recorded in the northern Aegean Sea in the eastern Mediterranean...

  3. Cephalopods distribution in the southern Aegean Sea

    Directory of Open Access Journals (Sweden)

    E. LEFKADITOU

    2003-06-01

    Full Text Available The present study concerns faunal composition and distribution of cephalopods in the southern Aegean Sea (35Ζ 13’ 19’’- 37Ζ 55’ 25’’ N, 23Ζ 00’ 15’’ - 28Ζ 15’ 37’’ E. Samples were collected from 708 hauls, obtained by an experimental bottom trawl net during eight surveys carried out in the summers of the years 1994-2001, as well as by commercial trawl net during four surveys carried out in September 1995, December 1995, May and September 1996. The hauls were performed at depths ranging from 16 to 778 m. A total of 34 species of cephalopod in 12 families were identified, including 11 oegopsid squid, 3 myopsid squid, 7 octopod, 3 cuttlefish and 10 sepiolid. Trawling with the experimental net resulted in the capturing of some uncommon pelagic species, such as Ctenopteryx siculaand Octopoteuthis sicula, which were recorded for the first time in the Aegean Sea. Most of the species showed a wide depth and geographical range. The species: Sepia officinalis, Sepietta neglecta, Sepietta obscuraand Sepiola rondeletiwere caught only on the continental shelf, whereas the Ancistroteuthis lichtensteini, Bathypolypous sponsalis, Brachioteuthis riisei, Chiroteuthis veranyi, Ctenopteryx sicula, Heteroteuthis dispar, Histioteuthis reversa, Neorossia caroli and Pyroteuthis margaritiferawere found only on the slope. The rest of the species extended in both continental shelf and slope. The spatial distribution of different species groups is discussed in relation to the hydrology and topography of the study area and the species ecology.

  4. Cephalopods distribution in the southern Aegean Sea

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    E. LEFKADITOU

    2012-12-01

    Full Text Available The present study concerns faunal composition and distribution of cephalopods in the southern Aegean Sea (35Ζ 13’ 19’’- 37Ζ 55’ 25’’ N, 23Ζ 00’ 15’’ - 28Ζ 15’ 37’’ E. Samples were collected from 708 hauls, obtained by an experimental bottom trawl net during eight surveys carried out in the summers of the years 1994-2001, as well as by commercial trawl net during four surveys carried out in September 1995, December 1995, May and September 1996. The hauls were performed at depths ranging from 16 to 778 m. A total of 34 species of cephalopod in 12 families were identified, including 11 oegopsid squid, 3 myopsid squid, 7 octopod, 3 cuttlefish and 10 sepiolid. Trawling with the experimental net resulted in the capturing of some uncommon pelagic species, such as Ctenopteryx siculaand Octopoteuthis sicula, which were recorded for the first time in the Aegean Sea. Most of the species showed a wide depth and geographical range. The species: Sepia officinalis, Sepietta neglecta, Sepietta obscuraand Sepiola rondeletiwere caught only on the continental shelf, whereas the Ancistroteuthis lichtensteini, Bathypolypous sponsalis, Brachioteuthis riisei, Chiroteuthis veranyi, Ctenopteryx sicula, Heteroteuthis dispar, Histioteuthis reversa, Neorossia caroli and Pyroteuthis margaritiferawere found only on the slope. The rest of the species extended in both continental shelf and slope. The spatial distribution of different species groups is discussed in relation to the hydrology and topography of the study area and the species ecology.

  5. An updated checklist of poisonous fishes of Turkish Aegean Sea

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    Bahar Bayhan

    2015-07-01

    Full Text Available The current status of marine poisonous fish species ranging in the Aegean Sea coastline in Turkey were introduced. Turkey is a peninsula surrounded by seas with different ecological features on three sides. The total length of shoreline is 8 333 km including the islands. The total number of fish species in Turkish seas is 512, of which 449 live in the Aegean Sea followed by the Mediterranean Sea (441 species, the Marmara Sea (257 species and the Black Sea (154species. On the Aegean Sea coasts, the richest sea regarding fish diversity, the number of poisonous fish species is also high. This mini-review revealed 51 poisonous fish species belonging to 14 families in the Turkish Aegean Sea. On the Aegean Sea coasts poisonous fish species can be categorized into three groups: (i Fish that contain venomous spines on the tail or on the operculum (ii Fish that carry poisonous bite and (iii Fish having poisonous flesh or liver. Poisoning fish that contain venomous spines on the tail or on the operculum mostly are dangerous because of their poisonous thorns whereas the passive poisonous fish species poison when they are eaten. These toxins can cause morbidity and rarely, mortality in humans. Apart from these, swallowing the blood of species such as European eel Anguilla anguilla and European conger Conger conger might also cause poisoning. Besides, as there has been an invasion of puffer fish especially on the Turkish Mediterranean and Aegean coasts in recent years, there is a danger in question. Thus, it is very important to particularly draw attention to these fish on the Turkish coasts.

  6. An updated checklist of poisonous ifshes of Turkish Aegean Sea

    Institute of Scientific and Technical Information of China (English)

    Bahar Bayhan; Murat Kaya

    2015-01-01

    The current status of marine poisonous fish species ranging in the Aegean Sea coastline in Turkey were introduced. Turkey is a peninsula surrounded by seas with different ecological features on three sides. The total length of shoreline is 8 333 km including the islands. The total number of fish species in Turkish seas is 512, of which 449 live in the Aegean Sea followed by the Mediterranean Sea (441 species), the Marmara Sea (257 species) and the Black Sea (154species). On the Aegean Sea coasts, the richest sea regarding fish diversity, the number of poisonous fish species is also high. This mini-review revealed 51 poisonous fish species belonging to 14 families in the Turkish Aegean Sea. On the Aegean Sea coasts poisonous fish species can be categorized into three groups: (i) Fish that contain venomous spines on the tail or on the operculum (ii) Fish that carry poisonous bite and (iii) Fish having poisonous flesh or liver. Poisoning fish that contain venomous spines on the tail or on the operculum mostly are dangerous because of their poisonous thorns whereas the passive poisonous fish species poison when they are eaten. These toxins can cause morbidity and rarely, mortality in humans. Apart from these, swallowing the blood of species such as European eelAnguilla anguillaand European congerConger congermight also cause poisoning. Besides, as there has been an invasion of puffer fish especially on the Turkish Mediterranean and Aegean coasts in recent years, there is a danger in question. Thus, it is very important to particularly draw attention to these fish on the Turkish coasts.

  7. Analytical chemistry in the Aegean Sea region: current status.

    Science.gov (United States)

    Samanidou, Victoria F

    2012-12-01

    The Eighth Aegean Analytical Chemistry Days Conference took place in Urla, İzmir, Turkey, from 16-20 September 2012. This conference is held every 2 years, organized alternately by analytical chemistry departments of Turkish and Greek universities, so that analytical chemists from the region around the Aegean Sea can exchange experience and knowledge based on their research in a large number of fields. This report summarizes the most interesting presentations and posters pertaining to bioanalytical work.

  8. Ecohydrodynamic model of the Baltic Sea. Part 1. Description of the ProDeMo model

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    Bogdan Ołdakowski

    2005-12-01

    Full Text Available The ProDeMo (Production and Destruction of Organic Matter Model, a 3D coupled hydrodynamic-ecological model, was formulated and applied to the whole Baltic Sea and the subregion of the Gulf of Gdansk. It describes nutrient cycles (phosphorus, nitrogen, silicon through the food web with 15 state variables, oxygen conditions and the parameterisation of water-sediment interactions. The present version of the model takes two groups of phytoplankton - diatoms and non-diatoms - as well as zooplankton into consideration. It covers the flow of matter and energy in the sea, including river discharges and atmospheric deposition. Numerical applications are embedded on a 1 NM grid for the Gulf of Gdansk and a 5 NM grid for the Baltic Sea.     Since the model results largely concur with observations, the model can be regarded as a reliable tool for analysing the behaviour of the Baltic ecosystem. Some examples of the spatial-temporal variability of the most important biological and chemical parameters are presented. The model results are compared with those of other modelling research in the Baltic Sea.     Both the ProDeMo model algorithm and its computing procedures need to be further developed. The next version should therefore enable more phytoplankton groups to be defined, for example cyanobacteria, which are able to take up molecular nitrogen from the atmosphere (nitrogen fixation. Additionally, the sediment phase should be divided into active and non-active layers.

  9. Coastal benthic diversity in the Black and Aegean Seas

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    A. ZENETOS

    2000-12-01

    Full Text Available Quantitative data pertaining to the composition of macrobenthic communities of soft bottoms along the coastal zones of the Black and Aegean Seas are reviewed. The study area includes one site in the Russian coastal zone, four sites in Ukraine (at depths 3-125 m, four sites in Bulgaria (at depths 12-83 m, and four sites in Greece (at depths 9-90 m. The species variety, population density and community diversity are compared between Seas, among regions and among stations. The fluctuation of these parameters in connection to anthropogenic impact (ranging from open undisturbed sites to those receiving heavy organic and chemical effluent are discussed. The low species number of benthic fauna in the Black Sea, as opposed to the richness of the Aegean Sea (three times higher a ratio well established for other marine groups, is not reflected in the overall abundance. Thus, the average population density of benthic organisms may reach 12352 ind per m2 in the Black Sea (Cocketrice sandy bank while in the Aegean it did not exceed 4,000 ind per m2 (Saronikos Gulf. Community diversity was always lower in the Black Sea than similar sites in the Aegean Sea. Within the various regions examined, the protected areas exhibited the most complex community structure.

  10. Coastal benthic diversity in the Black and Aegean Seas

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2012-12-01

    Full Text Available Quantitative data pertaining to the composition of macrobenthic communities of soft bottoms along the coastal zones of the Black and Aegean Seas are reviewed. The study area includes one site in the Russian coastal zone, four sites in Ukraine (at depths 3-125 m, four sites in Bulgaria (at depths 12-83 m, and four sites in Greece (at depths 9-90 m. The species variety, population density and community diversity are compared between Seas, among regions and among stations. The fluctuation of these parameters in connection to anthropogenic impact (ranging from open undisturbed sites to those receiving heavy organic and chemical effluent are discussed. The low species number of benthic fauna in the Black Sea, as opposed to the richness of the Aegean Sea (three times higher a ratio well established for other marine groups, is not reflected in the overall abundance. Thus, the average population density of benthic organisms may reach 12352 ind per m2 in the Black Sea (Cocketrice sandy bank while in the Aegean it did not exceed 4,000 ind per m2 (Saronikos Gulf. Community diversity was always lower in the Black Sea than similar sites in the Aegean Sea. Within the various regions examined, the protected areas exhibited the most complex community structure.

  11. The Cystoseira spp. Communities from the Aegean Sea (NE Mediterranean

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    B. MONTESANTO

    2012-12-01

    Full Text Available A synthetic study of qualitative and quantitative data from some algal communities dominated by different species of the genus Cystoseira has been carried out in three coastal areas of the Aegean Sea. Seasonal samples were taken from 10 stations and a list of 30 species presenting coverage values > 1% was dressed. Ecological indices, such as Shannon Diversity Index, Pielou Eveness and Bray-Curtis Similarity Index were calculate using the PRIMER software. The results from the Aegean Sea were compared with other Mediterranean areas, and the use of Cystoseira communities as ecological quality indicators was discussed.

  12. The Aegean Sea marine security decision support system

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    L. Perivoliotis

    2011-05-01

    Full Text Available As part of the integrated ECOOP (European Coastal Sea Operational observing and Forecasting System project, HCMR upgraded the already existing standalone Oil Spill Forecasting System for the Aegean Sea, initially developed for the Greek Operational Oceanography System (POSEIDON, into an active element of the European Decision Support System (EuroDeSS. The system is accessible through a user friendly web interface where the case scenarios can be fed into the oil spill drift model component, while the synthetic output contains detailed information about the distribution of oil spill particles and the oil spill budget and it is provided both in text based ECOOP common output format and as a series of sequential graphics. The main development steps that were necessary for this transition were the modification of the forcing input data module in order to allow the import of other system products which are usually provided in standard formats such as NetCDF and the transformation of the model's calculation routines to allow use of current, density and diffusivities data in z instead of sigma coordinates. During the implementation of the Aegean DeSS, the system was used in operational mode in order support the Greek marine authorities in handling a real accident that took place in North Aegean area. Furthermore, the introduction of common input and output files by all the partners of EuroDeSS extended the system's interoperability thus facilitating data exchanges and comparison experiments.

  13. The Aegean sea marine security decision support system

    Directory of Open Access Journals (Sweden)

    L. Perivoliotis

    2011-10-01

    Full Text Available As part of the integrated ECOOP (European Coastal Sea Operational observing and Forecasting System project, HCMR upgraded the already existing standalone Oil Spill Forecasting System for the Aegean Sea, initially developed for the Greek Operational Oceanography System (POSEIDON, into an active element of the European Decision Support System (EuroDeSS. The system is accessible through a user friendly web interface where the case scenarios can be fed into the oil spill drift model component, while the synthetic output contains detailed information about the distribution of oil spill particles and the oil spill budget and it is provided both in text based ECOOP common output format and as a series of sequential graphics. The main development steps that were necessary for this transition were the modification of the forcing input data module in order to allow the import of other system products which are usually provided in standard formats such as NetCDF and the transformation of the model's calculation routines to allow use of current, density and diffusivities data in z instead of sigma coordinates. During the implementation of the Aegean DeSS, the system was used in operational mode in order to support the Greek marine authorities in handling a real accident that took place in North Aegean area. Furthermore, the introduction of common input and output files by all the partners of EuroDeSS extended the system's interoperability thus facilitating data exchanges and comparison experiments.

  14. Major outputs of the recent multidisciplinary biogeochemical researches undertaken in the Aegean Sea

    Science.gov (United States)

    Lykousis, V.; Chronis, G.; Tselepides, A.; Price, N. B.; Theocharis, A.; Siokou-Frangou, I.; Van Wambeke, F.; Danovaro, R.; Stavrakakis, S.; Duineveld, G.; Georgopoulos, D.; Ignatiades, L.; Souvermezoglou, A.; Voutsinou-Taliadouri, F.

    2002-06-01

    The main outputs of a multidisciplinary and integrated studies are summarised. The results incorporate the latest biogeochemical researches, at basin scale, in the Aegean Sea (including thermohaline circulation studies, SPM dynamics, mass and energy fluxes, acknowledge biochemical processes in the euphotic and the benthic layer and benthic response to downward fluxes). The data were acquired within five (seasonal) research cruises, during 1997-1998. Data analysis and evaluation hence provided important new information on the functional processes of the Aegean ecosystem. In terms of water circulation, no new deep water formation in the Aegean Sea was observed, during 1997-1998, but rather intermediate water, due mainly to the mild winter conditions. All the biochemical parameters of the euphotic zone (nutrients, Particulate Organic Carbon (POC), chlorophyll- a, phytoplankton, primary and bacterial production), although high in the N. Aegean Sea reflect clearly the highly oligotrophic character of the Aegean Sea. In the N. Aegean, microbial food web was the main pathway of carbon, whereas in the S. Aegean, the food web could be classified as multivorous. An important Black Sea Water (BSW) signal was observed in the dissolved phase; this was especially pronounced in the Dissolved Organic Carbon (DOC), Mn and to a lesser degree to Cd, Cu and Ni concentrations. The downward material fluxes are higher in the N. Aegean, relative to the S. Aegean. Substantially higher values of near-bottom mass fluxes were measured in the deep basins of the N. Aegean, implying significant deep lateral fluxes of POM. The N. Aegean could be classified as a "continental margin" ecosystem, whilst the S. Aegean is a typical "oceanic margin" environment. There is a close relationship and, consequently, coupling between the near-bottom mass fluxes and the accumulation rates of organic matter (OM), with the near-bottom mineralisation, bioturbation, redox potential, oxygen consumption rates, the

  15. First observations of two talitrid crustaceans (Amphipoda: Talitridae from Gokceada island (NE Aegean Sea

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    B. CAMUR-ELIPEK

    2012-12-01

    Full Text Available The present paper reports the occurrence of Talitrus saltator (Montagu, 1808 and Orchestia gammarellus (Pallas, 1766 which are the first records from Gokceada (Imbroz Island (NE Aegean Sea. It should be noted that, T. saltator is a new record for the Aegean Sea coast of Turkey.

  16. Assimilating Ferry Box data into the Aegean Sea model

    Science.gov (United States)

    Korres, G.; Ntoumas, M.; Potiris, M.; Petihakis, G.

    2014-12-01

    Operational monitoring and forecasting of marine environmental conditions is a necessary tool for the effective management and protection of the marine ecosystem. It requires the use of multi-variable real-time measurements combined with advanced physical and ecological numerical models. Towards this, a FerryBox system was originally installed and operated in the route Piraeus-Heraklion in 2003 for one year. Early 2012 the system was upgraded and moved to a new high-speed ferry traveling daily in the same route as before. This route is by large traversing the Cretan Sea being the largest and deepest basin (2500 m) in the south Aegean Sea. The HCMR Ferry Box is today the only one in the Mediterranean and thus it can be considered as a pilot case. The analysis of FerryBox SST and SSS in situ data revealed the presence of important regional and sub-basin scale physical phenomena, such as wind-driven coastal upwelling and the presence of a mesoscale cyclone to the north of Crete. In order to assess the impact of the FerryBox SST data in constraining the Aegean Sea hydrodynamic model which is part of the POSEIDON forecasting system, the in situ data were assimilated using an advanced multivariate assimilation scheme based on the Singular Evolutive Extended Kalman (SEEK) filter, a simplified square-root extended Kalman filter that operates with low-rank error covariance matrices as a way to reduce the computational burden. Thus during the period mid-August 2012-mid January 2013 in addition to the standard assimilating parameters, daily SST data along the ferryboat route from Piraeus to Heraklion were assimilated into the model. Inter-comparisons between the control run of the system (model run that uses only the standard data set of observations) and the experiment where the observational data set is augmented with the FerryBox SST data produce interesting results. Apart from the improvement of the SST error, the additional assimilation of daily of FerryBox SST

  17. Frequent underwater volcanism in the central Aegean Sea

    Science.gov (United States)

    Huebscher, C.; Ruhnau, M.; Dehghani, G. A.

    2012-04-01

    The extinction of the Minoan culture in the mid second millennium BCE is a well known consequence of the Plinian eruption of Thera volcano (Santorini Island). Santorini is a member of the South Aegean arc forming a chain from the Gulf of Saronikos (Susaki, Egina, Poros, Methana) at West, to an area close to the Anatolian coast at East (Kos, Nisyros and minor islands), through the central part (Milos and Santorini island groups). Underwater volcanic activity was manifested historically only once. During 1649-1650 CE the Kolumbo underwater volcano evolved about 8 km northeast of Santorini. As a consequence of this eruption volcanic ash covered the entire Aegean area and a hazardous tsunami was triggered. Here we show by means of reflection seismic and magnetic data that underwater volcanism occurred more frequently in the central Aegean Sea than previously assumed. Seismic data show that Kolumbo constitutes of five vertically stacked cones of pyroclastic sediment plus at least four smaller cones on the flank of the volcano. The formation of Kolumbo started synchronous with Santorini Island. The entire volume of the Kolumbo pyroclastic cones is estimated to more than 15 cubic-kilometers. Several small-scale cones have been detected in the Anyhdros Basin some km north-east of Kolumbo, being previously interpreted as mud volcanoes by other authors. However, the similarity of seismic and magnetic signatures of these cones and Kolumbo strongly suggest that these cones were also created by underwater volcanism. Volcanic cones, Kolumbo and Santorini are situated along a NE-SW striking graben system that evolved during five extensional tectonic pulses in the Pliocene.

  18. Source mechanism of the 2014 Aegean Sea earthquake

    Science.gov (United States)

    Nakano, Masaru

    2016-04-01

    Rapid determination of centroid moment tensor (CMT) of earthquakes, namely the source centroid location, focal mechanism, and magnitude is important for early disaster responses and issuing Tsunami warnings. In order to evaluate capability of Turkey seismic network for rapid determinations of CMT, I investigate the source mechanism of the 2014 Aegean Sea earthquake (Mw 6.9). Although this event occur out of Turkey seismic network, I obtained stable CMT solution. The CMT solution of this earthquake represents a strike-slip fault, consistent with the geometry of the North Anatolian Fault (NAF), and the source-time function indicates that this event comprised several distinct subevents. Each subevent is considered to have ruptured a different fault segment. This observation indicates the existence of a mechanical barrier, namely a NAF segment boundary, at the hypocenter. I also determined CMT solutions of background seismicity. CMT solutions of background seismicity beneath the Aegean Sea represent strike-slip or normal faulting along the NAF or its branch faults. The tensional axes of these events are oriented northeast-southwest, indicating a transtensional tectonic regime. Beneath the Sea of Marmara, the CMT solutions represent mostly strike-slip faulting, consistent with the motion of the NAF, but we identified a normal fault event with a tensional axis parallel to the strike of the NAF. This mechanism indicates that a pull-apart basin, marking a segment boundary of the NAF, is developing there. Because ruptures of a fault system and large earthquake magnitudes are strongly controlled by the fault system geometry and fault length, mapping fault segments along NAF can help to improve the accuracy of scenarios developed for future disastrous earthquakes in the Marmara region.

  19. Nutrient exchange fluxes between the Aegean and Black Seas through the Marmara Sea

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    S. TUGRUL

    2012-12-01

    Full Text Available Long-term data obtained in the Turkish Strait System (TSS including the Sea of Marmara, the Dardanelles and Bosphorus straits, during 1990-2000, have permitted us to calculate seasonal and annual fluxes of water and nutrients (nitrate, phosphate exchanged between the Aegean and Black Seas through the TSS. Two-layer flow regimes in the TSS introduce the brackish waters of the Black Sea into the Aegean basin of the northeastern Mediterranean throughout the year. A counter flow in the TSS carries the salty Mediterranean water into the Black Sea via the Marmara deep basin. The annual volume influx from the Black Sea to the Marmara upper layer is nearly two-fold the salty water exported from the Marmara to the Black Sea via the Bosphorus underflow. The brackish Black Sea inflow is relatively rich in nitrate and phosphate in winter, decreasing to the lowest levels in late summer and autumn. Biologically labile nutrients of Black Sea origin are utilized in photosynthetic processes in the Marmara Sea and are partly exported to the Marmara lower layer. Eventually, the brackish Black Sea waters reach the Dardanelles Strait, with modified bio-chemical properties. On the other hand, the salty Mediterranean waters with low concentrations of nutrients enter the Marmara deep basin. During threir 6-7 year sojourn in the Marmara basin, the salty waters become enriched in nitrate (DIN and phosphate (DIP, due to oxidation of planktonic particles sinking from the Marmara surface layer. The annual nutrient inputs from the Black Sea to the Marmara basin were estimated as 8.17x108 moles of DIN and 4.25x107 moles of DIP, which are much less than the importation from the Marmara lower layer via the Bosphorus undercurrent. The salty Aegean water introduces nearly 6.13x108 moles of DIN and 2.79x107 moles of DIP into the Marmara lower layer. The estimated DIP outflux from the Aegean Sea is nearly 2 times less than the importation from the Marmara Sea via the Dardanelles

  20. High oxygen consumption rates in the deep layers of the North Aegean Sea (eastern Mediterranean

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    E. SOUVERMEZOGLOU

    2002-06-01

    Full Text Available Severe winter meteorological conditions promote dense water formation over the shelves of the North Aegean Sea. The newly formed dense water fills the deep basins of the North Aegean Sea, contributing to their ventilation and the downward transport of organic and inorganic material. The great bathymetric variability imposes limitations on the deep circulation and the communication between the various basins and makes the North Aegean Sea an appropriate area for the monitoring of oxygen consumption in the deep layers. Historical hydrographic data suggest that there was extensive production of dense water in the North Aegean Sea on two occasions during the last decade, the winters of 1987 and 1992-1993. Our data series from August 1986 to September 1989 and from March 1997 to February 1999, permitted us to follow, step by step, the oxygen consumption and the nutrient regeneration in the deep basins of the northern Aegean Sea during these periods of isolation. The organic matter reaching the bottom layer just after the deep water formation event is rich in labile and easily oxidizable material and its decomposition leads to a significant oxygen uptake during the first year of stagnation. The further decomposition of the remaining semi-labile and refractory material turns over on greater time scales, by consuming lesser amounts of oxygen. A more significant oxygen decrease is recorded in the eastern basin (Lemnos Basin of the North Aegean Trough, than in the central (Athos Basin and the western (North Sporades Basin ones and is attributed to the irregular contribution of the Black Sea Water (BSW to the water masses formed on the different shelves of the North Aegean Sea. Our results and the existing data on the Turkish straits showed that dissolved organic matter is the major constituent responsible for this high oxygen consumption. The slightly different particulate organic carbon fluxes to these depressions play a secondary role.

  1. High oxygen consumption rates in the deep layers of the North Aegean Sea (eastern Mediterranean

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    E. SOUVERMEZOGLOU

    2012-12-01

    Full Text Available Severe winter meteorological conditions promote dense water formation over the shelves of the North Aegean Sea. The newly formed dense water fills the deep basins of the North Aegean Sea, contributing to their ventilation and the downward transport of organic and inorganic material. The great bathymetric variability imposes limitations on the deep circulation and the communication between the various basins and makes the North Aegean Sea an appropriate area for the monitoring of oxygen consumption in the deep layers. Historical hydrographic data suggest that there was extensive production of dense water in the North Aegean Sea on two occasions during the last decade, the winters of 1987 and 1992-1993. Our data series from August 1986 to September 1989 and from March 1997 to February 1999, permitted us to follow, step by step, the oxygen consumption and the nutrient regeneration in the deep basins of the northern Aegean Sea during these periods of isolation. The organic matter reaching the bottom layer just after the deep water formation event is rich in labile and easily oxidizable material and its decomposition leads to a significant oxygen uptake during the first year of stagnation. The further decomposition of the remaining semi-labile and refractory material turns over on greater time scales, by consuming lesser amounts of oxygen. A more significant oxygen decrease is recorded in the eastern basin (Lemnos Basin of the North Aegean Trough, than in the central (Athos Basin and the western (North Sporades Basin ones and is attributed to the irregular contribution of the Black Sea Water (BSW to the water masses formed on the different shelves of the North Aegean Sea. Our results and the existing data on the Turkish straits showed that dissolved organic matter is the major constituent responsible for this high oxygen consumption. The slightly different particulate organic carbon fluxes to these depressions play a secondary role.

  2. Sensitivity of the N. AEGEAN SEA ecosystem to Black Sea Water inputs

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    G. PETIHAKIS

    2015-01-01

    Full Text Available The effect of Black Sea Water (BSW inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM (in the inflowing to the Aegean Sea, BSW appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic. In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain.

  3. Teleconnections, Midlatitude Cyclones and Aegean Sea Turbulent Heat Flux Variability on Daily Through Decadal Time Scales

    Science.gov (United States)

    Romanski, Joy; Romanou, Anastasia; Bauer, Michael; Tselioudis, George

    2013-01-01

    We analyze daily wintertime cyclone variability in the central and eastern Mediterranean during 1958-2001, and identify four distinct cyclone states, corresponding to the presence or absence of cyclones in each basin. Each cyclone state is associated with wind flows that induce characteristic patterns of cooling via turbulent (sensible and latent) heat fluxes in the eastern Mediterranean basin and Aegean Sea. The relative frequency of occurrence of each state determines the heat loss from the Aegean Sea during that winter, with largest heat losses occurring when there is a storm in the eastern but not central Mediterranean (eNOTc), and the smallest occurring when there is a storm in the central but not eastern Mediterranean (cNOTe). Time series of daily cyclone states for each winter allow us to infer Aegean Sea cooling for winters prior to 1985, the earliest year for which we have daily heat flux observations. We show that cyclone states conducive to Aegean Sea convection occurred in 1991/1992 and 1992/1993, the winters during which deep water formation was observed in the Aegean Sea, and also during the mid-1970s and the winters of 1963/1964 and 1968/1969. We find that the eNOTc cyclone state is anticorrelated with the North Atlantic Oscillation (NAO) prior to 1977/1978. After 1977/1978, the cNOTe state is anticorrelated with both the NAO and the North Caspian Pattern (NCP), showing that the area of influence of large scale atmospheric teleconnections on regional cyclone activity shifted from the eastern to the central Mediterranean during the late 1970s. A trend toward more frequent occurrence of the positive phase of the NAO produced less frequent cNOTe states since the late 1970s, increasing the number of days with strong cooling of the Aegean Sea surface waters.

  4. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean)

    OpenAIRE

    A. SIOULAS; CH. ANAGNOSTOU; A.P. KARAGEORGIS; C.D. GARBE-SCHONBERG

    2012-01-01

    Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elemen...

  5. On the response of the Aegean Sea to climatic variability: a review

    Science.gov (United States)

    Zervakis, V.; Georgopoulos, D.; Karageorgis, A. P.; Theocharis, A.

    2004-11-01

    The Aegean Sea is a region of special interest for the Mediterranean oceanographic community, as one of the dense-water formation sites of the Mediterranean, driving its thermohaline circulation. Early oceanographic literature exhibits significantly varying opinions regarding the role of the Aegean as a contributor to the water masses of the eastern Mediterranean. The higher temporal and spatial resolution studies that followed the introduction of Conductivity-Temperature-Depth (CTD) profilers in the 1980s, revealed that the various scenarios were within the interannual variability of dense water formation in the region. A peak in this variability was the appearance of the Eastern Mediterranean Transient event in the early 1990s. This phenomenon showed that the Aegean Sea has the potential to function as a source of dense water for the eastern Mediterranean; however, it takes over this role only sporadically, depending on the meteorological conditions over the eastern Mediterranean and, possibly, central/eastern Europe. The North Atlantic oscillation appears to be a contributor to this bimodal behaviour. Palaeoceanographic information has confirmed the large sensitivity of the Aegean Sea to climatic variability. Based on the available information, possible scenarios are examined for the response of the Aegean to the current climatic trends.

  6. First recording of the non-native species Beroe ovata Mayer 1912 in the Aegean Sea

    Directory of Open Access Journals (Sweden)

    T.A. SHIGANOVA

    2007-06-01

    Full Text Available A new alien species Beroe ovata Mayer 1912 was recorded in the Aegean Sea. It is most likely that this species spread on the currents from the Black Sea. Beroe ovata is also alien to the Black Sea, where it was introduced in ballast waters from the Atlantic coastal area of the northern America. The species is established in the Black Sea and has decreased the population of another invaderMnemiopsis leidyi, which has favoured the recovery of the Black Sea ecosystem.We compare a new 1 species with the native species fam. Beroidae from the Mediterranean and predict its role in the ecosystem of the Aegean Sea using the Black Sea experience.

  7. First recording of the non-native species Beroe ovata Mayer 1912 in the Aegean Sea

    Directory of Open Access Journals (Sweden)

    T.A. SHIGANOVA

    2012-12-01

    Full Text Available A new alien species Beroe ovata Mayer 1912 was recorded in the Aegean Sea. It is most likely that this species spread on the currents from the Black Sea. Beroe ovata is also alien to the Black Sea, where it was introduced in ballast waters from the Atlantic coastal area of the northern America. The species is established in the Black Sea and has decreased the population of another invaderMnemiopsis leidyi, which has favoured the recovery of the Black Sea ecosystem.We compare a new 1 species with the native species fam. Beroidae from the Mediterranean and predict its role in the ecosystem of the Aegean Sea using the Black Sea experience.

  8. ESA ResGrow: Trial cases for SAR lifting. Aegean Sea

    DEFF Research Database (Denmark)

    Badger, Merete; Hasager, Charlotte Bay; Hahmann, Andrea N.

    This report presents results related to lifting of wind maps retrieved from satellite Synthetic Aperture Radar (SAR) over the Aegean Sea. For this case study DTU Wind Energy collaborates with the Hellenic Wind Energy Association. Preliminary results have been presented to HWEA and their feedback ...

  9. Modeling the buoyancy-driven Black Sea Water outflow into the North Aegean Sea

    Directory of Open Access Journals (Sweden)

    Nikolaos Kokkos

    2016-04-01

    Full Text Available A three-dimensional numerical model was applied to simulate the Black Sea Water (BSW outflux and spreading over the North Aegean Sea, and its impact on circulation and stratification–mixing dynamics. Model results were validated against satellite-derived sea surface temperature and in-situ temperature and salinity profiles. Further, the model results were post-processed in terms of the potential energy anomaly, ϕ, analyzing the factors contributing to its change. It occurs that BSW contributes significantly on the Thracian Sea water column stratification, but its signal reduces in the rest of the North Aegean Sea. The BSW buoyancy flux contributed to the change of ϕ in the Thracian Sea by 1.23 × 10−3 W m−3 in the winter and 7.9 × 10−4 W m−3 in the summer, significantly higher than the corresponding solar heat flux contribution (1.41 × 10−5 W m−3 and 7.4 × 10−5 W m−3, respectively. Quantification of the ϕ-advective term crossing the north-western BSW branch (to the north of Lemnos Island, depicted a strong non-linear relation to the relative vorticity of Samothraki Anticyclone. Similar analysis for the south-western branch illustrated a relationship between the ϕ-advective term sign and the relative vorticity in the Sporades system. The ϕ-mixing term increases its significance under strong winds (>15 m s−1, tending to destroy surface meso-scale eddies.

  10. Interaction between trench retreat and Anatolian escape as recorded by neogene basins in the northern Aegean Sea

    NARCIS (Netherlands)

    Beniest, A.; Brun, J. P.; Gorini, C.; Crombez, V.; Deschamps, R.; Hamon, Y.; Smit, Jeroen

    2016-01-01

    The evolution of the North Aegean Sea is studied through the development of three deep basins: the North Aegean Trough, the North Skyros Basin and the Ikaria Basin. Bathymetric data, a 2D seismic dataset and the well-investigated stratigraphic records of the onshore deep basins of northern Greece

  11. Large-scale bioprospecting of cyanobacteria, micro- and macroalgae from the Aegean Sea.

    Science.gov (United States)

    Montalvão, Sofia; Demirel, Zeliha; Devi, Prabha; Lombardi, Valter; Hongisto, Vesa; Perälä, Merja; Hattara, Johannes; Imamoglu, Esra; Tilvi, Supriya Shet; Turan, Gamze; Dalay, Meltem Conk; Tammela, Päivi

    2016-05-25

    Marine organisms constitute approximately one-half of the total global biodiversity, being rich reservoirs of structurally diverse biofunctional components. The potential of cyanobacteria, micro- and macroalgae as sources of antimicrobial, antitumoral, anti-inflammatory, and anticoagulant compounds has been reported extensively. Nonetheless, biological activities of marine fauna and flora of the Aegean Sea have remained poorly studied when in comparison to other areas of the Mediterranean Sea. In this study, we screened the antimicrobial, antifouling, anti-inflammatory and anticancer potential of in total 98 specimens collected from the Aegean Sea. Ethanol extract of diatom Amphora cf capitellata showed the most promising antimicrobial results against Candida albicans while the extract of diatom Nitzschia communis showed effective results against Gram-positive bacterium, S. aureus. Extracts from the red alga Laurencia papillosa and from three Cystoseira species exhibited selective antiproliferative activity against cancer cell lines and an extract from the brown alga Dilophus fasciola showed the highest anti-inflammatory activity as measured in primary microglial and astrocyte cell cultures as well as by the reduction of proinflammatory cytokines. In summary, our study demonstrates that the Aegean Sea is a rich source of species that possess interesting potential for developing industrial applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. A Spatial Analysis and Game Theoretical Approach Over the Disputed Islands in the Aegean Sea

    Science.gov (United States)

    2016-06-01

    definition of “dependent” or “adjacent” islands. There are no such definitions in terms of international law , which causes another point of conflict...the application of game theory in an arbitration scheme. 22 Figure 10. Six-nautical-mile expansion of territorial waters in the Aegean Sea...Turkey after the application of Nash arbitration scheme 34 Figure 17. Weighted utilities of the islands for the twelve-nautical-mile expansion

  13. Fate of the Evros River suspended particulate matter in the northern Aegean Sea

    Science.gov (United States)

    Kanellopoulos, Theodore D.; Angelidis, Michael O.; Georgopoulos, Dimitrios; Karageorgis, Aristomenis P.

    2009-06-01

    Evros River is the most important river flowing into the North Aegean Sea (eastern Mediterranean) in terms of freshwater discharge, and the second largest one of Eastern Europe after the Danube River. Salinity and temperature measurements, together with suspended particulate matter concentrations were obtained in various depths at 14 stations in the adjacent Alexandroupolis Gulf during four seasons (June 1998, September 1998, February 1999 and March 2000) in order to investigate the particle dynamics and distributions in the northern Aegean Sea. Analysis of the collected data, together with particle observations under the scanning electron microscope and study of satellite images showed that, under certain circumstances driven by the hydrological and wind regime of the area, the Evros River particulate matter, with the associated pollutants, can be transferred far away from the estuary and implicitly comprise a hazardous factor for the environmental status of the northern Aegean Sea. This fact, combined with the future construction of the Burgas-Alexandroupolis pipeline, may cause a negative impact on the studied natural ecosystem.

  14. A new alien bryozoan Celleporaria brunnea (Hincks, 1884 in the Aegean Sea (eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    Ferah Koçak

    2007-03-01

    Full Text Available The ascophoran Bryozoa Celleporaria brunnea, a new record for the Mediterranean Sea, was found on Mytilus galloprovincialis collected in the inner part of Izmir Bay (Aegean Sea, Turkey in September 2004. The species was previously reported from the Pacific coast of the United States. Its occurrence in the polluted inner part of Izmir Bay, near Alsancak Harbour, suggests that it has been newly introduced to the area, possibly via ship hulls. The morphological, ecological and zoogeographical characteristics of the species are given and discussed.

  15. Wind Atlas of Aegean Sea with SAR data

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Hasager, Charlotte Bay; Badger, Merete

    2013-01-01

    in the North Sea and Baltic Sea but it is the first time it is used for a large scale Mediterranean area. The available dataset is provided by European Space Agency’s ENVISAT mission and recorded between 2002 and 2012. The presented method gives the ability to calculate the wind resource map of an offshore...

  16. Circulation and hydrological characteristics of the North Aegean Sea: a contribution from real-time buoy measurements

    Directory of Open Access Journals (Sweden)

    K. NITTIS

    2002-06-01

    Full Text Available In the framework of the POSEIDON Project, a network of open sea oceanographic buoys equipped with meteorological and oceanographic sensors has been operational in the Aegean Sea since 1998. The analysis of upper-ocean physical data (currents at 3m, temperature and salinity at 3-40m depths collected during the last 2 years from the stations of the North Aegean basin indicates a strong temporal variability of flow field and hydrological characteristics in both synoptic and seasonal time scales. The northern part of the basin is mainly influenced by the Black Sea Water outflow and the mesoscale variability of the corresponding thermohaline fronts, while the southern stations are influenced by the general circulation of the Aegean Sea with strong modulations caused by the seasonally varying atmospheric forcing.

  17. Circulation and hydrological characteristics of the North Aegean Sea: a contribution from real-time buoy measurements

    Directory of Open Access Journals (Sweden)

    K. NITTIS

    2012-12-01

    Full Text Available In the framework of the POSEIDON Project, a network of open sea oceanographic buoys equipped with meteorological and oceanographic sensors has been operational in the Aegean Sea since 1998. The analysis of upper-ocean physical data (currents at 3m, temperature and salinity at 3-40m depths collected during the last 2 years from the stations of the North Aegean basin indicates a strong temporal variability of flow field and hydrological characteristics in both synoptic and seasonal time scales. The northern part of the basin is mainly influenced by the Black Sea Water outflow and the mesoscale variability of the corresponding thermohaline fronts, while the southern stations are influenced by the general circulation of the Aegean Sea with strong modulations caused by the seasonally varying atmospheric forcing.

  18. Mesozooplankton biomass and abundance in Cyprus coastal waters and comparison with the Aegean Sea (eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    C. C.S. HANNIDES

    2015-07-01

    Full Text Available Here we conduct the first comprehensive assessment of mesozooplankton abundance, biomass, and taxa composition in Cyprus coastal waters (Levantine Sea.  Mesozooplankton abundance and biomass sampled at several locations around the island ranged from 153 – 498 individuals m-3 and 0.7 – 5.2 mg dry weight m-3, respectively, with significantly larger biomass observed in winter-early spring (March than in summer (September.  The community was dominated by calanoid and cyclopoid copepods throughout the year (80% of total numbers, with higher abundances of predatory taxa (chaetognaths and medusae in winter and cladocerans in summer.  Overall, we find that coastal mesozooplankton communities around Cyprus appear to be more similar to communities in offshore waters or those around the island of Rhodes than to communities along the mainland Levantine coast.  We further highlight regional differences in the eastern Mediterranean by comparing our data with mesozooplankton in the western Aegean (Saronikos Gulf and northeastern Aegean Sea (NEA.  Distinct spatial differences were observed, for example anthropogenic influences in the Saronikos Gulf and the outflow of Modified Black Sea Water in the NEA drove generally greater biomass and abundance in these regions.  Overall, our comparison supports the concept of a latitudinal gradient in oligotrophy in the eastern Mediterranean, with ultra-oligotrophic conditions found in the Levantine Sea.

  19. Trichoptera biodiversity of the Aegean and Adriatic sea basins in the republic of Kosovo.

    Science.gov (United States)

    Ibrahimi, Halil; Kučinić, Mladen; Gashi, Agim; Grapci-Kotori, Linda

    2014-01-01

    We present the first preliminary inventory of Trichoptera taxa in the Aegean and Adriatic Sea basins in Kosovo that have previously received poor and fragmentary attention. Adult caddisflies were collected using ultraviolet (UV) light traps in 13 stations in areas of the Aegean Sea and Adriatic Sea drainage basins in Kosovo. Nineteen species out of 82, reported in this article, are first records for the Kosovo caddisfly fauna. Five genera are recorded for the first time in Kosovo: Brachycentrus, Ecclisopteryx, Psilopteryx, Thremma, and Oecetis. During this investigation, we found several Southeastern European endemic and rare species whose previous known distribution was limited to particular areas of this region, as well as other species whose distribution is considerably enlarged by this investigation: Polycentropus ierapetra, Polycentropus irroratus, Chaetopteryx stankovici, Drusus schmidi, Drusus tenellus, Potamophylax goulandriourum, Oecetis notata, and Notidobia melanoptera. Even though this article is a result of a limited sampling effort, it increases the number of Trichoptera taxa recorded for the Republic of Kosovo to 131. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  20. Bacterial and organic matter distribution in the sediments of the Thracian Sea (NE Aegean Sea)

    Science.gov (United States)

    Polymenakou, Paraskevi N.; Fragkioudaki, Glykeria; Tselepides, Anastasios

    2007-10-01

    Recently, black carbon has been introduced as the form of carbon that may be separated from the biologically mediated carbon cycle thereby representing the non-bioavailable fraction of the estimated organic carbon. It has been speculated that the bioavailability of organic matter may be a limiting factor for the presence of active bacteria within the sediments. In order to address this question, marine sediments were collected from the Thracian Sea (Eastern Mediterranean), a complex system impacted by riverine inputs and Black Sea water masses. In addition to counts of total bacteria, we estimated the fraction of active bacteria by using a destaining step to the DAPI staining method. Black carbon was also estimated following the thermal oxidation method in order to determine the fraction of the refractory organic matter. The fraction of black carbon to total organic carbon varied from 16% to 53% indicating that black carbon constitutes a significant pool of sedimentary organic carbon in the Thracian sea. A fraction ranging from 18% to 97% was scored as nucleoid containing cells. We did not record any significant differences in the fraction of nucleoid-containing bacteria among sediment depths ( Pblack carbon and bioavailable organic carbon with sediment depth ( P<0.05) indicating that benthic consumers are not the key regulators of the organic matter pool in these sediments but have a minor effect. A possible reason for these observations and for the uncoupling between the active bacterial fraction and the bioavailability of organic matter could be (i) the presence of refractory components in the estimated bioavailable organic matter and (ii) the hydrological and geological complexity of the study area. The North Aegean marginal slopes are highly unstable experiencing frequent seismic events. These events are capable of inducing sediment transport from the upper slopes thus altering the entire sediment profile. On the other hand, the significant correlations that

  1. North-eastern Aegean sea: an effort to estimate steady-state N & P budgets during September 1998

    Directory of Open Access Journals (Sweden)

    E. KRASAKOPOULOU

    2012-12-01

    Full Text Available The north-eastern Aegean sea, characterised by a complex topographical structure, is the area where highly saline waters of Levantine and South-Central Aegean origin are diluted by the outflowing through the Dardanelles of less saline waters of Black Sea origin and by river runoff from the Greek and Turkish mainland. Salinity and nutrient data collected during the INTERREG-I project are used to develop budget calculations and empirical models according to the LOICZ biogeochemical modelling guidelines. The results of the study indicate that the dissolved inorganic nitrogen and phosphorus fluxes imported into the NE Aegean through the Dardanelles are less important than it was believed in the past. Overall, the system acts as a net sink of DIN and DIP, as well as being a net producer of organic matter, as primary production exceeds respiration. Moreover, the system appears to fix more nitrogen than is lost through denitrification.

  2. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. SIOULAS

    2012-12-01

    Full Text Available Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elements associated with: (1 biogenic carbonates; (2 terrigenous alumino-silicates and (3 sapropelic layers. R-mode factor analysis applied on the carbonate-free corrected data-set defined four significant factors: (1 the “detrital alumino-silicate factor” represented by Si, Al, Na, K, Rb, Zr, Pb and inversely related to Ca, Mg, and Sr; (2 a “hydrothermal factor” loaded with Cr, Ni, Co, Cu, Fe; (3 the “volcanic ash factor” with high loadings for Ti, Al, Fe, Na and (4 a “sapropel factor” represented by Ba, Mo, and Zn. High factor scores for the “hydrothermal factor” were observed in sediment samples proximal to Nisyros Isl., suggesting a potential hydrothermal influence. Red-brown oxides and crusts dredged from this area support further this possibility. The use of factor analysis enabled for a better understanding of the chemical elements associations that remained obscured by correlation analysis.

  3. Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea)

    Science.gov (United States)

    Hübscher, Christian; Ruhnau, M.; Nomikou, P.

    2015-01-01

    Here we show for the first time the 3D-structural evolution of an explosive submarine volcano by means of reflection seismic interpretation. Four to five vertically stacked circular and cone-shaped units consisting mainly of volcaniclastics build the Kolumbo underwater volcano which experienced its first eruption > 70 ka ago and its last explosive eruption 1650 AD, 7 km NE of Santorini volcano (southern Aegean Sea). The summed volume of volcaniclastics is estimated to range between 13-22 km3. The entire Kolumbo volcanic complex has a height of ≥ 1 km and a diameter of ≥ 11 km. All volcaniclastic units reveal the same transparent reflection pattern strongly suggesting that explosive underwater volcanism was the prevalent process. Growth faults terminate upwards at the base of volcaniclastic units, thus representing a predictor to an eruption phase. Similarities in seismic reflection pattern between Kolumbo and near-by volcanic cones imply that the smaller cones evolved through explosive eruptions as well. Hence, the central Aegean Sea experienced several more explosive eruptions (≥ 23) than previously assumed, thus justifying further risk assessment. However, the eruption columns from the smaller volcanic cones did not reach the air and- consequently - no sub-aerial pyroclastic surge was created. The Anydros basin that hosts Kolumbo volcanic field opened incrementally NW to SE and parallel to the Pliny and Strabo trends during four major tectonic pulses prior to the onset of underwater volcanism.

  4. Geochemical characteristics of late Quaternary sediments from the southern Aegean Sea (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. SIOULAS

    2000-12-01

    Full Text Available Ten cores from the southern Aegean Sea have been logged for their lithological composition and seventy-three sub-samples were analysed for the determination of major and trace elements concentrations. Four lithological units were identified, namely, mud, volcanic, turbidite and sapropel. On the basis of the “Z-2” Minoan ash layer radiocarbon age sedimentation rates for the southern Aegean Sea were estimated at 3.26 to 4.15 cm kyr -1. Simple correlation analysis revealed three groups of elements associated with: (1 biogenic carbonates; (2 terrigenous alumino-silicates and (3 sapropelic layers. R-mode factor analysis applied on the carbonate-free corrected data-set defined four significant factors: (1 the “detrital alumino-silicate factor” represented by Si, Al, Na, K, Rb, Zr, Pb and inversely related to Ca, Mg, and Sr; (2 a “hydrothermal factor” loaded with Cr, Ni, Co, Cu, Fe; (3 the “volcanic ash factor” with high loadings for Ti, Al, Fe, Na and (4 a “sapropel factor” represented by Ba, Mo, and Zn. High factor scores for the “hydrothermal factor” were observed in sediment samples proximal to Nisyros Isl., suggesting a potential hydrothermal influence. Red-brown oxides and crusts dredged from this area support further this possibility. The use of factor analysis enabled for a better understanding of the chemical elements associations that remained obscured by correlation analysis.

  5. On the fecundity of the bogue Boops boops (Linnaeus, 1758) in the Turkish Aegean Sea

    Institute of Scientific and Technical Information of China (English)

    Burcu Taylan; Bahar Bayhan

    2015-01-01

    Objective: To determine the fecundity of Boops boops (B. boops) from Aegean Sea coast of Turkey. Methods: A total of 470 specimens of B. boops were collected monthly from November in 2008 to October of 2009 in Izmir Bay (central Aegean Sea). Total length and total weight of each fish were measured and the maturity stages of gonads were determined. About 30 mature ovariums were taken to determine fecundity and oocysts were counted by using gravimetric method. Results: About 210 were females (44.7%) and 226 males (48.1%) while 34 (7.2%) were hermafrodite in terms of sexuality with sex ratio (female: male) of 0.93:1.00. The fecundity of the bogue was assessed by the gravimetric method with 30 ovaries from females between the total length of 19.6 and 27.6 cm [(mean: 23.5 ± 2.1) cm]. Estimates of total fecundity varied between 33072 and 66123 oocytes (mean: 49008 ± 8826) and fecundity–total length, fecundity–weight relationships were expressed as :F = 8207.6e0.075TL, F = 30297e0.003TW respectively. Conclusions: The results of the study will contribute to the reproductive biology of B. boops and will be useful for management of fisheries.

  6. Temporal and spatial variability of nutrients and oxygen in the North Aegean Sea during the last thirty years

    Directory of Open Access Journals (Sweden)

    Ε. SOUVERMEZOGLOU

    2015-01-01

    Full Text Available Inorganic nutrient and dissolved oxygen data collected in the North Aegean Sea during 1986 - 2008 were analyzed in order to evaluate the role of the inflowing Black Sea originated surface water (BSW in the nutrient regime of the area.  In periods of high buoyancy inflow from Dardanelles strait, a reduction of inorganic nutrients in the surface layer is observed along the north-west route of the BSW; in parallel, the underlying layer of Levantine intermediate water revealed an increase of inorganic nutrients, receiving the degradation material from the surface layer. The above spatial patterns suggest a contribution of the BSW to the observed enhanced production of the North Aegean Sea. Anomalously low buoyancy inflow of BSW combined with severe winter meteorological conditions promote deep water formation events. The physical and chemical characteristics of the deep waters found in the different basins of the North Aegean Sea in 1997 (following the deep water formation in winters of 1992-1993 differed from those observed after the formation in winter 1987. These differences were probably related to the drastic changes occurred in the deep waters of the Eastern Mediterranean in the early 1990, by the Eastern Mediterranean Transient. Considering that deep water formation processes provide occasionally inorganic nutrients to the euphotic layer, it seems that BSW through its uninterrupted supply of small quantities of nutrients should play an additional role in the production in the North Aegean Sea.

  7. Dissolved and Suspended Polycyclic Aromatic Hydrocarbons (PAH in the North Aegean Sea

    Directory of Open Access Journals (Sweden)

    I. HATZIANESTIS

    2012-12-01

    Full Text Available The distribution and sources of polycyclic aromatic hydrocarbons (PAH were investigated in the seawater of the North Aegean Sea. The measured PAH concentrations in SPM are generally considered as elevated for open sea waters and were evenly distributed in the area. Their levels in the dissolved phase (1.6-33.0 ng/l were much higher than those encountered in the corresponding particulate phases (0.04-10.2 ng/l. The PAH patterns in both phases were dominated by the three ring aromatics and their alkylated derivatives, reflecting a predominant contribution of fossil hydrocarbons probably related to ship traffic, whereas no significant inputs from the rivers outfalling in the area were detected. In bottom waters PAH values were generally lower, whereas a higher depletion of the petroleum PAH in comparison with the pyrolytic ones according to depth was observed.

  8. Dynamics of Late Quaternary sapropel periods documented by micropaleontological and sedimentological data from North Aegean Sea

    Science.gov (United States)

    Gkaniatsa, Georgia; Kontakiotis, George; Antonarakou, Assimina; Drinia, Hara; Anastasakis, George

    2017-04-01

    Located at the interface of the mid/high latitude climate system and affected by the North Atlantic Oscillation and the monsoonal system over Africa, the Mediterranean Sea has a unique potential to record the occurrence and phasing of climatic changes in both systems. In particular, the eastern Mediterranean Sea is more sensitive and faster responding to external forcing than the open ocean due to smaller size and partial isolation. A manifestation of the high sensitivity of the eastern Mediterranean sedimentary environment to climatic forcing is the periodic deposition of dark colored and organic matter rich sediments, termed "sapropels". In particular their formation is closely correlated with the reduction in ventilation, due to low salinity surface water layer, leading to anoxia at the bottom and preservation of organic matter, and/or the increase in primary productivity in the photic zone. To address which factor is more responsible for the sapropel's formation, a high-resolution study of planktonic foraminiferal abundances in two cores from North Aegean was carried out. Their response reflects the essential information about the paleoceanographic evolution in the water column in terms of stratification and productivity during the different sapropel events covering the last 90 kyrs. Cores M 22-67 and M22-68 were recovered from the water depths of 175 and 305 m respectively in the Chios Basin (North Aegean Sea). Both cores approximately span the last 90 ka, exposing the most recent S1 and the older S3 sapropels. They particularly exposed at very high resolution compared to most occurrences throughout the eastern Mediterranean, because of the highest sediment accumulation rates occurred in the study basin. Application of this information to the study hemipelagic sediment cores, through the planktonic foraminiferal analyses, suggests that we further contribute to existing evidence of climatic instability during sapropel deposition in eastern Mediterranean Sea

  9. First record of the non-indigenous fangtooth moray Enchelycore anatina from Rhodes Island, south- eastern Aegean Sea

    Directory of Open Access Journals (Sweden)

    S. KALOGIROU

    2012-12-01

    Full Text Available The collection of one specimen of the non-indigenous fangtooth moray Enchelycore anatina of tropical Atlantic origin was for the first time found in an area of south eastern Aegean Sea. This record may indicate a recent establishment of the species on the coasts of Rhodes Island and a possible expansion of it on the coastal rocky habitats.

  10. Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)

    NARCIS (Netherlands)

    Aravadinou, E.; Xypolias, P.; Chatzaras, V.; Iliopoulos, I.; Gerogiannis, N.

    2016-01-01

    New geological and structural mapping combined with kinematic and amphibole chemistry analyses is used to investigate the deformation history of the Cycladic Blueschist Unit (CBU) on Sifnos Island (Cyclades, Aegean Sea). We concentrate on north Sifnos, an area characterized by exceptionally well-pre

  11. Calc-alkaline lavas from the volcanic complex of Santorini, Aegean Sea, Greece : a petrological, geochemical and stratigraphic study

    NARCIS (Netherlands)

    Huijsmans, J.P.P.

    1985-01-01

    This thesis presents the results of a petrological-geochemical- and stratigraphic study of the calc-alkaline lavas from Santorini, Aegean Sea, Greece. The volcanic complex of Santorini consists of seven eruption centres, of which some have been active contemporaneous. The eruption centres in the

  12. Food-web traits of the North Aegean Sea ecosystem (Eastern Mediterranean) and comparison with other Mediterranean ecosystems

    Science.gov (United States)

    Tsagarakis, K.; Coll, M.; Giannoulaki, M.; Somarakis, S.; Papaconstantinou, C.; Machias, A.

    2010-06-01

    A mass-balance trophic model was built to describe the food-web traits of the North Aegean Sea (Strymonikos Gulf and Thracian Sea, Greece, Eastern Mediterranean) during the mid-2000s and to explore the impacts of fishing. This is the first food-web model representing the Aegean Sea, and results were presented and discussed in comparison to other previous ecosystems modelled from the western and the central areas of the basin (South Catalan and North-Central Adriatic Seas). Forty functional groups were defined, covering the entire trophic spectrum from lower to higher trophic levels. Emphasis was placed on commercial invertebrates and fish. The potential ecological role of the invasive ctenophore, Mnemiopsis leidyi, and several vulnerable groups (e.g., dolphins) was also explored. Results confirmed the spatial productivity patterns known for the Mediterranean Sea showing, for example, that the total biomass is highest in N.C. Adriatic and lowest in N. Aegean Sea. Accordingly, food-web flows and several ecosystem indicators like the mean transfer efficiency were influenced by these patterns. Nevertheless, all three systems shared some common features evidencing similarities of Mediterranean Sea ecosystems such as dominance of the pelagic fraction in terms of flows and strong benthic-pelagic coupling of zooplankton and benthic invertebrates through detritus. The importance of detritus highlighted the role of the microbial food-web, which was indirectly considered through detritus dynamics. Ciliates, mesozooplankton and several benthic invertebrate groups were shown as important elements of the ecosystem linking primary producers and detritus with higher trophic levels in the N. Aegean Sea. Adult anchovy was shown as the most important fish group in terms of production, consumption and overall effect on the rest of the ecological groups in the model, in line with results from the Western Mediterranean Sea. The five fishing fleets considered (both artisanal and

  13. Flux measurements in the surface Marine Atmospheric Boundary Layer over the Aegean Sea, Greece.

    Science.gov (United States)

    Kostopoulos, V E; Helmis, C G

    2014-10-01

    Micro-meteorological measurements within the surface Marine Atmospheric Boundary Layer took place at the shoreline of two islands at northern and south-eastern Aegean Sea of Greece. The primary goal of these experimental campaigns was to study the momentum, heat and humidity fluxes over this part of the north-eastern Mediterranean Sea, characterized by limited spatial and temporal scales which could affect these exchanges at the air-sea interface. The great majority of the obtained records from both sites gave higher values up to factor of two, compared with the estimations from the most widely used parametric formulas that came mostly from measurements over open seas and oceans. Friction velocity values from both campaigns varied within the same range and presented strong correlation with the wind speed at 10 m height while the calculated drag coefficient values at the same height for both sites were found to be constant in relation with the wind speed. Using eddy correlation analysis, the heat flux values were calculated (virtual heat fluxes varied from -60 to 40 W/m(2)) and it was found that they are affected by the limited spatial and temporal scales of the responding air-sea interaction mechanism. Similarly, the humidity fluxes appeared to be strongly influenced by the observed intense spatial heterogeneity of the sea surface temperature.

  14. The Etesian wind system and wind energy potential over the Aegean Sea

    Science.gov (United States)

    Dafka, Stella; Xoplaki, Elena; Garcia-Bustamante, Elena; Toreti, Andrea; Zanis, Prodromos; Luterbacher, Juerg

    2013-04-01

    The Mediterranean region lies in an area of great climatic interest since it is influenced by some of the most relevant mechanisms of the global climate system. In the frame of the three Europe 2020 priorities for a smart, sustainable and inclusive economy delivering high levels of employment, productivity and social cohesion, the Mediterranean energy plan is of paramount importance at the European level, being an area with a significant potential for renewable energy from natural sources that could play an important role in responding to climate change effects over the region. We present preliminary results on a study of the Etesian winds in the past, present and future time. We investigate the variability and predictability of the wind field over the Aegean. Statistical downscaling based on several methodologies will be applied (e.g. canonical correlation analysis and multiple linear regression). Instrumental time series, Era-Interim and the 20CR reanalyses will be used. Large-scale climate drivers as well as the influence of local/regional factors and their interaction with the Etesian wind field will be addressed. Finally, the Etesian wind resources on the present and future climate will be assessed in order to identify the potential areas suitable for the establishment of wind farms and the production of wind power in the Aegean Sea.

  15. Progress of KOERI Tsunami Warning System for the Eastern Mediterranean, Aegean and Black Seas

    Science.gov (United States)

    Necmioglu, Ocal; Meral Ozel, Nurcan; Ozer Sozdinler, Ceren; Yilmazer, Mehmet; Cokacar, Tulay; Comoglu, Mustafa; Pinar, Ali; Kekovali, Kivanc

    2016-04-01

    This presentation provides a progress report on the activities of the Bogazici University / Kandilli Observatory and Earthquake Research Institute - Regional Earthquake and Tsunami Monitoring Center (KOERI-RETMC) which provides services as a Candidate Tsunami Service Provider (CTSP) of ICG/NEAMTWS in the Eastern Mediterranean, Aegean and Black Seas since 1 July 2012. KOERI continues to operate 178 BB and 97 strong motion and 6 short period sensors and the regional coverage includes 77 stations from GFZ and additional 16 stations through bilateral agreements. One radar-type tide-gauge has been installed in Fethiye within the framework of "Inexpensive Device for Sea-Level Measurement" (IDSL) initiative offered as donation by the EC/JRC and planning is in progress for the possible installation of three more IDSLs in selected locations in the Aegean Sea coast of Turkey. The capabilities and the limitations of HF Radar technology for the purpose of tsunami detection in the Eastern Mediterranean has been identified and the maturity and the applicability of these systems for the possible use under the Tsunami Warning System has been determined. The development of the TsuComp as a user-friendly interface to be used in the assessment of tsunamigenic potential and as a single-point entry for message dissemination has been finalized. The work towards the creation of Tsunami Inundation Maps at the Tsunami Forecast Points in Turkey is near finalization. This work is partially funded by project ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839. The authors would like to thank EC/JRC and Mr. Alessandro Annunziato for their continuous support in the operational activities of RETMC and IDSL initiative.

  16. Seroprevalence of Toscana virus among residents of Aegean Sea islands, Greece.

    Science.gov (United States)

    Anagnostou, Vassiliki; Papa, Anna

    2013-01-01

    Phleboviruses, among them Toscana virus (TOSV), are endemic in the Mediterranean countries. In the present study sera collected from 219 apparently healthy individuals residents of seven islands in the Aegean Sea, Greece, were tested for the detection of TOSV IgG antibodies. Overall, TOSV IgG antibodies were detected in 46/219 (21%) individuals. Samos and Evia islands presented the highest seroprevalence (40% and 34.78%, respectively). There was no significant difference among males and females, while increased age was significantly associated with seropositivity. TOSV, and phleboviruses in general, have to be included in the differential diagnosis of febrile or acute neurological cases among residents or travelers in Mediterranean countries during the summer time, especially when sand fly bites are reported.

  17. Seasonal Nutrient Enrichment Experiment in Homa Lagoon (İzmir Bay, Aegean Sea

    Directory of Open Access Journals (Sweden)

    Banu Kutlu

    2014-05-01

    Full Text Available In order to determine the effects of nutrient (P, Si, NH4, NO3 enrichment on the growth of phytoplankton in Homa Lagoon (İzmir Bay, Aegean Sea, experiments of enrichment with discontinuous cultures have been executed seasonally in 2007. In our study, the elements limiting the growth of phytoplankton were NO3, P and Si in spring season, N and P in summer season, and NH4 in autumn and winter seasons. So, it has been determined that the addition of nitrogen (N and phosphor (P has led significant change in biomass and growth of phytoplankton. It has also been observed that diatom and dinoflagellate species have grown under various concentrations of, especially, Silicate (Si and nitrogen (N.

  18. Illegal immigration in the eastern Aegean Sea: a new source of marine litter

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2015-10-01

    Full Text Available The maritime area dominates the current increasing wave of illegal immigration to Europe. The Greek islands of the eastern Aegean Sea are the main entrance points of immigrants arriving from the coasts of Turkey. Immigration to the Greek islands is mainly conducted with inflatable boats, which are abandoned upon arrival along the coasts together with other items such as life-jackets, inflatable tubes, and clothing. This novel type of marine litter dominates many beaches and becomes increasingly abundant. Two beaches in Lesvos Island were surveyed for marine litter, and immigration-related items were found to account for more than 97% of marine litter by weight. Immigration-related littering adds pressure on marine biodiversity and the local economy, impacting the recreational value of beaches.

  19. Illegal immigration in the eastern Aegean Sea: a new source of marine litter

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2015-11-01

    Full Text Available The maritime area dominates the current increasing wave of illegal immigration to Europe. The Greek islands of the eastern Aegean Sea are the main entrance points of immigrants arriving from the coasts of Turkey. Immigration to the Greek islands is mainly conducted with inflatable boats, which are abandoned upon arrival along the coasts together with other items such as life-jackets, inflatable tubes, and clothing. This novel type of marine litter dominates many beaches and becomes increasingly abundant. Two beaches in Lesvos Island were surveyed for marine litter, and immigration-related items were found to account for more than 97% of marine litter by weight. Immigration-related littering adds pressure on marine biodiversity and the local economy, impacting the recreational value of beaches.

  20. Styela plicata: a new promising bioindicator of heavy metal pollution for eastern Aegean Sea coastal waters.

    Science.gov (United States)

    Aydın-Önen, S

    2016-11-01

    As part of a research project, the concentrations of Cd, Cu, Pb, V, and Zn in the tissues of Styela plicata were investigated for the first time to determine if S. plicata is a suitable biological indicator for biomonitoring of heavy metals in eastern Aegean Sea coastal waters. To examine the relationships, heavy metal levels in suspended particulate matters (SPMs) and sediments were also determined. According to the results, the mean metal levels in SPM, sediments, and S. plicata samples could be arranged in the following order of abundance: Zn > Cu > Pb > V > Cd. As for heavy metal levels, significant positive correlations were noted between Cd-Pb, Cd-V, Cd-Zn, Cu-V, and Pb-V in SPM; Cd-Zn, Cu-Zn, Pb-Cd, Pb-Cu, and Pb-Zn in sediment; and Cu-Pb, Cu-Zn, and Pb-Zn in S. plicata samples. Positive relationships between these metals showed that they were originated from same sources and that they were associated with each other. Based on the findings, Zn, Cu, and Pb concentrations in suspended particulate matters, sediments, and S. plicata samples were generally represented with higher levels at stations that were used for boating, shipping, and related activities. As S. plicata is a strongest accumulator of V, the relatively low V levels observed in this study may indicate the lack of anthropogenic sources of this metal in the sampling stations. In conclusion, suspended particulate matter and sediment can be useful tool to detect the pollution status of the marine environment. Furthermore, the findings of this study highlighted that S. plicata is a promising alternative for the monitoring of heavy metal pollution for eastern Aegean Sea coasts.

  1. Performance of Statistical Temporal Downscaling Techniques of Wind Speed Data Over Aegean Sea

    Science.gov (United States)

    Gokhan Guler, Hasan; Baykal, Cuneyt; Ozyurt, Gulizar; Kisacik, Dogan

    2016-04-01

    Wind speed data is a key input for many meteorological and engineering applications. Many institutions provide wind speed data with temporal resolutions ranging from one hour to twenty four hours. Higher temporal resolution is generally required for some applications such as reliable wave hindcasting studies. One solution to generate wind data at high sampling frequencies is to use statistical downscaling techniques to interpolate values of the finer sampling intervals from the available data. In this study, the major aim is to assess temporal downscaling performance of nine statistical interpolation techniques by quantifying the inherent uncertainty due to selection of different techniques. For this purpose, hourly 10-m wind speed data taken from 227 data points over Aegean Sea between 1979 and 2010 having a spatial resolution of approximately 0.3 degrees are analyzed from the National Centers for Environmental Prediction (NCEP) The Climate Forecast System Reanalysis database. Additionally, hourly 10-m wind speed data of two in-situ measurement stations between June, 2014 and June, 2015 are considered to understand effect of dataset properties on the uncertainty generated by interpolation technique. In this study, nine statistical interpolation techniques are selected as w0 (left constant) interpolation, w6 (right constant) interpolation, averaging step function interpolation, linear interpolation, 1D Fast Fourier Transform interpolation, 2nd and 3rd degree Lagrange polynomial interpolation, cubic spline interpolation, piecewise cubic Hermite interpolating polynomials. Original data is down sampled to 6 hours (i.e. wind speeds at 0th, 6th, 12th and 18th hours of each day are selected), then 6 hourly data is temporally downscaled to hourly data (i.e. the wind speeds at each hour between the intervals are computed) using nine interpolation technique, and finally original data is compared with the temporally downscaled data. A penalty point system based on

  2. First occurrence of the invasive alien species Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae on the coast of Greece (Elefsis Bay; Aegean Sea

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

    Full Text Available The present study reports on the occurrence of two specimens of the alien species Polydora cornutaBosc, 1802, in Elefsis Bay, the Saronikos Gulf (Aegean Sea, eastern Mediterranean. This is the firstrecord of this invasive alien species on the coast of Greece and the second report in the eastern MediterraneanSea after its first finding in Izmir Bay (on the Turkish Aegean coast. This finding enhances its distributionalpattern within the Mediterranean

  3. Meteorological influences on the surface hydrographic patterns of the North Aegean Sea:

    Directory of Open Access Journals (Sweden)

    Georgios Sylaios

    2011-03-01

    Full Text Available Hydrographic data from the North Aegean Sea were used to examine the summer variability of surface water masses during the period 1998-2001. Attention was placed on the surface hydrographic features of the area, such as the Black Sea Water (BSW plume expansion, the frontal characteristics of the BSW with the Levantine Intermediate Water (LIW and the variability of submesoscale hydrographic features (such as the Samothraki Anticyclone. Strong southerly wind stresses were found responsible for relaxing the horizontal density gradients across the BSW-LIW frontal zone and displacing this front to the north of Lemnos Island, thus suppressing the Samothraki Anticyclone towards the Thracian Sea continental shelf. Under northerly winds, the BSW-LIW front returns to its regular position (south of Lemnos Island, thus allowing the horizontal expansion of the Samothraki gyre up to the Athos Peninsula. Present results indicate the importance of medium-term wind stress effects on the generation of Samothraki Anticyclone suppression/expansion events.

  4. Simulation of Tsunami Related To Caldera Collapse and A Case Study of Thera Volcano In Aegean Sea

    Science.gov (United States)

    Yalciner, A. C.; Imamura, F.; Synolakis, C. E.

    Based on the seismic characteristics of the Aegean Sea and the surrounding regions, the earthquakes and volcanic eruptions had also generated several tsunamis in his- tory. It is therefore extremely important that the possible occurrence of a tsunami in these regions require careful and intensive investigations. One such approach is the investigation of the historical documents and determines the degree of effects of those tsunamis The eruption of volcano in Thera (Santorini) island in late Minoan time in Aegean sea resulted in a submarine caldera have generated tsunamis. The generation, and coastal effects of those tsunami waves have not been understood yet. However the tsunami deposits suggesting the sea water inundation related to Thera eruption are found at the sites, Crete (Gouves), Anatolia (Didim, Fethiye) and presented in Minoura et. al. (2000). In this study the generation of tsunamis related to caldera collapse, relation between the size, duration and level of caldera collapse with the generation of tsunami are in- vestigated by mathematical modeling and compared. The tsunami propagation related to this Thera caldera collapse is also investigated in this very irregular bathymetric domain of Southern Aegean Sea with TUNAMI-N2. The results are discussed and compared with the existing findings at coastal sites. Minoura et. al., (2000), "Discovery of Minoan Tsunami Deposits" Geology, V: 28, No 1 pp: 59-62

  5. Physical and underway data collected aboard the OCEANUS during cruise OC454-01 in the Aegean Sea, Alboran Sea and others from 2009-07-06 to 2009-07-25 (NODC Accession 0104318)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104318 includes physical and underway data collected aboard the OCEANUS during cruise OC454-01 in the Aegean Sea, Alboran Sea and others from...

  6. Description of the first Lessepsian squid migrant, Sepioteuthis lessoniana (CEPHALOPODA: Loliginidae, in the Aegean Sea (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    E. LEFKADITOU

    2012-12-01

    Full Text Available Loliginid squids of the Sepioteuthis lessoniana complex are widely spread in the Indo-Pacific Ocean, where they constitute a commercially important resource for neritic fisheries. Sepioteuthis lessoniana is the only Lessepsian squid migrant till now, recorded for the first time in the Mediterranean in 2002 along the Turkish Levantine coasts. Two maturing males, with mantle lengths 193 mm and 244 mm, have been recently caught near the coasts of Rhodes Island (SE Aegean, extending the species distribution northward, into Hellenic waters. Their identity was confirmed by comparison of the main body, beak characteristics and morphometric measurements with those available in the literature for this species. Suspected expansion of the Lessepsian loliginid into the Aegean Sea, due to the gradual warming of the sea, is discussed.

  7. Radioactivity and metal concentrations in marine sediments associated with mining activities in Ierissos Gulf, North Aegean Sea, Greece.

    Science.gov (United States)

    Pappa, F K; Tsabaris, C; Ioannidou, A; Patiris, D L; Kaberi, H; Pashalidis, I; Eleftheriou, G; Androulakaki, E G; Vlastou, R

    2016-10-01

    Marine sediment samples were collected from Ierissos Gulf, N Aegean Sea, close to the coastal mining facilities. Measurements of radionuclide and metal concentrations, mineral composition and grain size distribution were performed. The concentrations of (226)Ra, (235)U and trace metals showed enhanced values in the port of Stratoni compared with those obtained near to Ierissos port. The dose rates received by marine biota were also calculated by the ERICA Assessment Tool and the results indicated no significant radiological risk.

  8. Calc-alkaline lavas from the volcanic complex of Santorini, Aegean Sea, Greece : a petrological, geochemical and stratigraphic study

    OpenAIRE

    Huijsmans, J.P.P.

    1985-01-01

    This thesis presents the results of a petrological-geochemical- and stratigraphic study of the calc-alkaline lavas from Santorini, Aegean Sea, Greece. The volcanic complex of Santorini consists of seven eruption centres, of which some have been active contemporaneous. The eruption centres in the northern part of Santorini mainly produced lava flows in contrast with a long-lived eruption centre in the southern part, that mainly produced pyroclastic deposits. The lavas and pyroclastics of Santo...

  9. The Sponge Community of a Subtidal Area with Hydrothermal Vents: Milos Island, Aegean Sea

    Science.gov (United States)

    Pansini, M.; Morri, C.; Bianchi, C. N.

    2000-11-01

    Sponges were sampled by SCUBA diving at six subtidal rocky sites, three of which were close to hydrothermal vents, a common feature on the sea-floor off the south-east coast of Milos. Twenty-five species (2 Calcarea and 23 Demospongiae) were found, few compared with the 589 recorded for the Mediterranean, but an important addition to the scant information on the sponge fauna of the Aegean Sea. The number of species found at vent sites was consistently higher than that found at non-vent sites, but no vent-obligate species could be identified. However, Geodia cydonium and three species of Cliona ( C. copiosa, C. nigricans and C. rhodensis) showed a tendency to colonize vent areas. The former might take advantage of increased silica availability, the latter of the enhanced deposition of carbonates near vents. Substratum cover by sponges (estimated from wire-framed photographs of 0·7 m 2), varied greatly both among and within sites, mostly according to slope. Most sponge species preferred vertical to overhanging, shaded substrata. Proximity to vents seemed to have little or no influence on sponge cover, notwithstanding a primary effect on species diversity.

  10. Long-Term Marine Traffic Monitoring for Environmental Safety in the Aegean Sea

    Science.gov (United States)

    Giannakopoulos, T.; Gyftakis, S.; Charou, E.; Perantonis, S.; Nivolianitou, Z.; Koromila, I.; Makrygiorgos, A.

    2015-04-01

    The Aegean Sea is characterized by an extremely high marine safety risk, mainly due to the significant increase of the traffic of tankers from and to the Black Sea that pass through narrow straits formed by the 1600 Greek islands. Reducing the risk of a ship accident is therefore vital to all socio-economic and environmental sectors. This paper presents an online long-term marine traffic monitoring work-flow that focuses on extracting aggregated vessel risks using spatiotemporal analysis of multilayer information: vessel trajectories, vessel data, meteorological data, bathymetric / hydrographic data as well as information regarding environmentally important areas (e.g. protected high-risk areas, etc.). A web interface that enables user-friendly spatiotemporal queries is implemented at the frontend, while a series of data mining functionalities extracts aggregated statistics regarding: (a) marine risks and accident probabilities for particular areas (b) trajectories clustering information (c) general marine statistics (cargo types, etc.) and (d) correlation between spatial environmental importance and marine traffic risk. Towards this end, a set of data clustering and probabilistic graphical modelling techniques has been adopted.

  11. Observations on a population of the sea anemone Anemonia viridis (Forskal, 1775) in the North Aegean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Chariton Chintiroglou, C. [Thessaloniki, Aristotle Univ. (Greece). Dept. of Zoology

    1996-12-31

    The present paper is concerned with the structural aspects of Anemonia viridis populations found in the North Aegean Sea. It was found that mean wet weight and density of anemone populations increases with depth and distance from shore. Differences in the structure of the Anemonia viridis populations were attributed both to the specific hydrodynamic characteristics of the biotopes and to a number biotic interactions. From our results and t previous investigations the adoption of three different lifestyles by the anemones was assumed.: (1) a colonial form, with population densities around 650 individuals per m{sup 2}, found in substrates exposed to increased hydrodynamism; (2) a colonial form, with lower densities (90 indiv. per m{sup 2}), found in less exposed sites; (3) finally, large individuals in deeper waters chose a solitary lifestyle, as mechanical stresses were much lower.

  12. Aliphatic hydrocarbon levels in turbot and salmon farmed close to the site of the Aegean Sea oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Pineiro, M.E. [Institute of Investigation and Food Analysis, La Coruna (Spain); Gonzalez-Barros, S.T.C.; Lozano, J.S. [Area Nutrition and Bromatology, La Coruna (Spain)] [and others

    1996-12-31

    After the Andros Patria oil spill, the most serious oil tanker accident to occur off the coast of Galicia (N.W. Spain) was the running aground and subsequent conflagration of the Aegean Sea supertanker outside the northern Spanish port of La Coruna (December 3rd 1992). Approximately 60,000 tonnes of Brent oil were spilled into the Atlantic Ocean in the cited coastal region. Subsequently, an impropitious combination of a high tide and a change in wind direction caused the resulting slick to rapidly spread into the port. Measures aimed at cleaning up affected areas and evacuating the ca. 11,215 tonnes of oil remaining in the supertanker were immediately implemented. However, within just a few days the resulting contamination had killed some 15000 turbot juveniles and larvae, which are cultivated in fish farms close to the accident site. The environmental impact of major oil spillages has been widely studied. Several scientists have suggested that, in terms of the negative effects on the seawater quality and productive capacity of the affected maritime regions, the magnitudes of the Aegean Sea and Amoco Cadiz accidents are comparable. This paper reports variations over time of aliphatic hydrocarbon levels in turbot and Atlantic salmon sampled from fish farms close to the site of the Aegean Sea oil spill. 6 refs., 2 figs., 1 tab.

  13. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    K. ANTONAKAKIS

    2012-12-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  14. The Errors-in-Variables approach for the validation of the WAM wave model in the Aegean Sea

    Directory of Open Access Journals (Sweden)

    T.H. SOUKISSIAN

    2012-12-01

    Full Text Available In previous studies, wave fi elds from the 3rd-generation wave model WAM-Cycle 4 have been validated by using in situ buoy measurements in the Aegean Sea within the framework of the POSEIDON project; however, limitations of the data sets, concerning mainly the short distance of the buoys from the shore and the short length of the data, render those validation studies incomplete. In this work, signifi cant wave height forecasts obtained from WAM-Cycle 4 wave model are validated by means of TOPEX/Poseidon (T/P data in specifi c offshore locations in the central part of the North Aegean Sea. The linear structural relationship between the two data sets has been modelled by implementing the Error- In-Variables approach, assuming that both T/P data and WAM results are subjected to errors. The underestimation of signifi cant wave height from WAM, which has been concluded from the comparison with buoys at near-shore points, is also observed from the WAM-T/P comparison at offshore locations, thus being considered of general validity for the Aegean Sea. In addition, a correction relation for the WAM model results, based on the linear structural relationship, is proposed and applied.

  15. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    K. ANTONAKAKIS

    2011-06-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  16. Morphometric identification of Tylosurus acus imperialis in the North Aegean Sea

    Directory of Open Access Journals (Sweden)

    George Minos

    2015-11-01

    Full Text Available Increasing numbers of Tylosurus needlefishes together with common Belone needlefishes appeared in Thermaikos Gulf (North Aegean Sea, Greece from 2012 to 2014, especially from May to August. The Tylosurus individuals were identified because of the absence of gill rakers and the presence of black thin lateral keel on caudal peduncle. From June 2013 to July 2014, 112 specimens of Tylosurus needlefishes were collected from commercial fisheries and a detailed morphometric and meristic analysis was applied for species identification. Measurements were recorded on each specimen, for six distance characters (TL, SL, FL, BL, HL, MBH. The length of fins (pectoral, ventral, dorsal, anal was measured, various proportions between body and fin length were estimated and the number of fin rays was counted. Total length (TL ranged from 59.3 to 111.6 cm. The soft rays in ventral fins were 6, in dorsal fin were 23-26 (mainly 24 with 53% and in anal fin were 21-23 (mainly 22 with 51%. Body length to head length (BL/HL ranged from 2 to 2.82, BL to pectoral fins length (BL/P ranged from 8.3 to 10.8, BL to ventral fins length (BL/V ranged from 10.9 to 17.7, BL to anterior dorsal fin lobe height (BL/D ranged from 10.5 to 15.3 and BL to anterior anal fin lobe height (BL/A ranged from 9.3 to 14.3. The anal fin lobe ranged from 4.9 to 7.4% of standard length. Moreover, the specimens had greater size in length, greater values in morphometrics (i.e. BL/P etc and higher values in meristics than those reported for the congeneric species Tylosurus choram (Rüppell, 1837 and Tylosurus crocοdilus (Péron & Lesueur, 1821. The resulted diagnostic features are in accordance to the literature for the systematics of Tylosurus acus imperialis (Rafinesque, 1810. Thus, specimens were identified as T. acus imperialis confirming its occurrence in Thermaikos Gulf waters appearing the northern geographic expansion in the Aegean Sea.

  17. Spatial and temporal variability of tropospheric ozone (O3) in the boundary layer above the Aegean Sea (eastern Mediterranean)

    Science.gov (United States)

    Kouvarakis, G.; Vrekoussis, M.; Mihalopoulos, N.; Kourtidis, K.; Rappenglueck, B.; Gerasopoulos, E.; Zerefos, C.

    2002-09-01

    To study the spatial and temporal variability of tropospheric ozone in the marine boundary layer over the Aegean Sea (eastern Mediterranean), an O3 analyzer has been installed onboard of a passenger vessel traveling on a regular basis in the Aegean Sea (from Heraklion/Crete 35°30'N, 25°13'E to Thessaloniki 40°64'N, 22°97'E) during a period of 14 months (August 1999 to November 2000). In addition, O3 data have been obtained on a daily basis at the regional background station of Finokalia (Crete; 35°30'N, 25°70'E) since September 1997, short-term measurements of O3 were performed over Crete during the PAUR II campaign (May 1999), and the first O3 data from a rural area (40°32'N, 23°50'E) close to Thessaloniki at the north of Greece have been collected from March 2000 to January 2001. This survey extensive points out the existence of a well-defined seasonal cycle in boundary layer O3 with maximum in summer both above the Aegean Sea and at Finokalia. However, the seasonal signal (defined as the summer/winter ratio) is not constant and varies as a function of air mass origin from 1.33 to 1.15 for the N-NE and SW-S sectors, respectively, in line with the geographical location of the O3 precursor sources. Our data show the absence of any significant longitudinal gradient over Crete at least during spring and autumn and the absence of significant latitudinal gradient between the north and south Aegean Sea during all seasons for air masses having similar origin. The above results indicate that long-range transport is the main factor accounting for the elevated O3 levels above the eastern Mediterranean Sea. Thus (1) O3 data from Finokalia, where the longest time series are available for the area, have regional significance and (2) over the entire Aegean basin, ozone values are above the 32 ppbv European Union (EU) phytotoxicity limit throughout the year and above the 53 ppbv EU health protection limit most of the time during the dry season of the year. The very

  18. Climate change effects on the marine characteristics of the Aegean and Ionian Seas

    Science.gov (United States)

    Makris, Christos; Galiatsatou, Panagiota; Tolika, Konstantia; Anagnostopoulou, Christina; Kombiadou, Katerina; Prinos, Panayotis; Velikou, Kondylia; Kapelonis, Zacharias; Tragou, Elina; Androulidakis, Yannis; Athanassoulis, Gerasimos; Vagenas, Christos; Tegoulias, Ioannis; Baltikas, Vassilis; Krestenitis, Yannis; Gerostathis, Theodoros; Belibassakis, Kostantinos; Rusu, Eugen

    2016-12-01

    This paper addresses the effects of estimated climate change on the sea-surface dynamics of the Aegean and Ionian Seas (AIS). The main aim is the identification of climate change impacts on the severity and frequency of extreme storm surges and waves in areas of the AIS prone to flooding. An attempt is made to define design levels for future research on coastal protection in Greece. Extreme value analysis is implemented through a nonstationary generalized extreme value distribution function, incorporating time harmonics in its parameters, by means of statistically defined criteria. A 50-year time span analysis is adopted and changes of means and extremes are determined. A Regional Climate Model (RegCM3) is implemented with dynamical downscaling, forced by ECHAM5 fields under 20C3M historical data for the twentieth century and the SRES-A1B scenario for the twenty-first century. Storm surge and wave models (GreCSSM and SWAN, respectively) are used for marine climate simulations. Comparisons of model results with reanalysis and field data of atmospheric and hydrodynamic characteristics, respectively, are in good agreement. Our findings indicate that the dynamically downscaled RegCM3 simulation adequately reproduces the present general circulation patterns over the Mediterranean and Greece. Future changes in sea level pressure and mean wind fields are estimated to be small, yet significant for marine extremes. In general, we estimate a projected intensification of severe wave and storm surge events during the first half of the twenty-first century and a subsequent storminess attenuation leading to the resettlement of milder extreme marine events with increased prediction uncertainty in the second half of the twenty-first century.

  19. Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)

    Science.gov (United States)

    Monioudi, Isavela N.; Velegrakis, Adonis F.; Chatzipavlis, Antonis E.; Rigos, Anastasios; Karambas, Theophanis; Vousdoukas, Michalis I.; Hasiotis, Thomas; Koukourouvli, Nikoletta; Peduzzi, Pascal; Manoutsoglou, Eva; Poulos, Serafim E.; Collins, Michael B.

    2017-03-01

    The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths economic resource of the Aegean archipelago.

  20. Offshore wind speed and wind power characteristics for ten locations in Aegean and Ionian Seas

    Indian Academy of Sciences (India)

    Haralambos S Bagiorgas; Giouli Mihalakakou; Shafiqur Rehman; Luai M Al-Hadhrami

    2012-08-01

    This paper utilizes wind speed data measured at 3 and 10 m above water surface level using buoys at 10 stations in Ionian and Aegean Seas to understand the behaviour of wind and thereafter energy yield at these stations using 5 MW rated power offshore wind turbine. With wind power densities of 971 and 693 W/m2 at 50 m above water surface level, Mykonos and Lesvos were found to be superb and outstanding windy sites with wind class of 7 and 6, respectively. Other locations like Athos, Santorini and Skyros with wind power density of more than 530 W/m2 and wind class of 5 were found to be the excellent sites. Around 15–16% higher winds were observed at 10 m compared to that at 3 m. Lower values of wind speed were found during summer months and higher during winter time in most of the cases reported in the present work. Slightly decreasing (∼2% per year) linear trends were observed in annual mean wind speed at Lesvos and Santorini. These trends need to be verified with more data from buoys or from nearby onshore meteorological stations. At Athos and Mykonos, increasing linear trends were estimated. At all the stations the chosen wind turbine could produce energy for more than 70% of the time. The wind speed distribution was found to be well represented by Weibull parameters obtained using Maximum likelihood method compared to WAsP and Method of Moments.

  1. Bacterial pollution, activity and heterotrophic diversity of the northern part of the Aegean Sea, Turkey.

    Science.gov (United States)

    Çiftçi Türetken, Pelin S; Altuğ, Gülşen

    2016-02-01

    Isolation and characterization studies of marine heterotrophic bacteria are important to describe and understand eco-metobolism of the marine environments. In this study, diversity and community structures of the culturable heterotrophic bacteria, metabollicaly active bacteria and bacterial pollution in the coastal and offshore areas of Gökçeada Island, in the Northern Aegean Sea, Turkey were investigated from March 2012 to November 2013. The primary hydrographic parameters were recorded in situ. The frequency of the metabolically active bacteria was determined by using a modified staining technique. The indicator bacteria were determined by using membrane filtration technique; 126 bacteria isolates, 24 of them first records for this region, were identified using an automated micro-identification system, VITEK2 Compact30. The results showed that detected bacterial community profiles were significantly different when compared with previous studies conducted in polluted marine areas of Turkey. High frequency of faecal bacteria detected at station 2 indicated that increasing human activities and terrestrial pollution sources are shaping factors for possible risks, regarding recreational uses of this region, in the summer seasons.

  2. On some rarely caught fish in the southeastern Aegean Sea (Greece, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    Maria Corsini-Foka

    2015-11-01

    Full Text Available The marine region of the Dodecanese Islands (Greece is heavily affected by climate changes, intensification of anthropogenic interferences and biological invasions. Its ichthyofauna diversity is still poorly known, despite the development of marine research during the last decades, both in shallow and deep waters, and the increasing interest of fishermen to biodiversity knowledge and conservation. Regardless of its oligotrophic character, with only 1-3 % of the total Greek fishery production (ELSTAT, 2015, at least 60 % of the total fish species known in the Hellenic seas (510 has been recorded in the area (Papaconstantinou, 2014. Between 2009 and 2014, 14 uncommon species - Alopias superciliosus, Gymnura altavela, Aulopus filamentosus, Sudis hyalina, Gymnothorax unicolor, Ophisurus serpens, Nemichthys scolopaceus, Lophotus lacepede, Naucrates ductor, Alectis alexandrinus, Brama brama, Pomadasys incisus, Schedophilus ovalis and Mola mola - were captured. The first records of P. incisus and S. ovalis in the area significantly enlarge their known distribution in the Hellenic Aegean waters (Papaconstantinou, 2014. The capture of L. lacepede (approx. 140 cm total length in Patmos (2011 confirms the occurrence of this rare species in the Dodecanese, given that a juvenile is preserved at the Hydrobiological Station of Rhodes since the 1950s, and constitutes the third official record in the Aegean waters, after Gökova Bay and Chalkidiki findings (Bilecenoğlu et al., 2001; Minos et al., 2013. The captures of S. hyalina (2011 and N. scolopaceus (2014 confirm their occurrence some years after their first reports in the same area in 2004 and 2002 respectively (Corsini-Foka, 2009. The occurrence of A. superciliosus, a species infrequent in local fishery, is poorly documented in the Mediterranean and the species is considered scarce or rare in the basin (Madiraca and Davidov, 2015. The scattered records of the remaining above species contribute to monitor

  3. a Structural and Thermochronological Study of Santorini Detachment in Santorini Island, Aegean Sea

    Science.gov (United States)

    Marsellos, A.; Foster, D. A.; Min, K. K.; Kamenov, G. D.; Kidd, W. S.; Garver, J. I.; Kyriakopoulos, K.

    2012-12-01

    Extension in the Aegean has been very prominent since early Miocene expressed by a series of detachments, opening of the Cretan basin, arc expansion and plutons, with a peak of extensional activity at 10-16 Ma across the south Aegean. In Santorini, which is the southernmost Cyclades island and closest to the forearc, intrusion of an unexposed pluton to a depth equivalent to modern sea level took place at about 9.5 Ma (Skarpelis et al., 1992). In this study, Zircon fission-track (ZFT) and apatite (U-Th)/He (AHe) data from the Athinios metamorphic rocks exposed in Santorini caldera distinguish an upper metamorphic cooling unit associated with Early-Middle Eocene exhumation (46.3 ± 2.8 Ma, ZFT; 49.34 ± 2.9 Ma, AHe) from a lower metamorphic unit of Middle-Late Miocene (10.9 ± 0.7 Ma, ZFT; 9.4 ± 0.3 Ma, AHe) exhumation ages. The upper unit shows mineral lineations that range from N-S to NE-SW trending while the lower unit shows lineations ranging from N-S to NW-SE trending. U-Pb (LA-MC-ICP-MS) zircon data from mica-schists in the lower Santorini metamorphic unit show a prominent Pan-African signature similar to the Phyllite-quartzite unit (PQU) rocks exposed along the forearc in Kythera, Peloponnese and western Crete. The NW-SE stretching lineations in the lower unit imply an arc-parallel extension. Similar arc-parallel extension took place between 10-13 in PQU rocks in the west Crete-Kythera-south Peloponnese area (Marsellos et al., 2010). The lower unit shows ductile structures affected by top to the S shearing while the upper unit by top to the N shearing. A 3D projection of the mineral lineation dip angles along N-S direction shows a C' shear band of top to the N shearing that has affected the entire structural stack. Early brittle structures, which appear to be re-oriented normal faults, and show top to the S displacement. Later normal faults show similar shear sense. A tectonic model that could explain the above structures shows that initial exhumation of the

  4. Recovery of the commercial sponges in the central and southeastern Aegean Sea (NE Mediterranean after an outbreak of sponge disease

    Directory of Open Access Journals (Sweden)

    J. CASTRITSI-CATHARIOS

    2011-01-01

    Full Text Available The distribution and biometry of commercial sponges (Porifera in coastal areas of the central and southeastern Aegean Sea was investigated to estimate the recovery progress of the populations eight years after the first appearance of sponge disease. Signs of the disease were detected only in 1.6% of the harvested sponges. Multivariate analysis on the percentage abundance of sponges showed two distinct groups among the sixteen fishing grounds studied: the eight deep (50-110 m and the eight shallow ones (<40 m. The group from the deep depths consisted of Spongia officinalis adriatica, S. agaricina and S. zimocca. The infralittoral zone was characterized by the presence of Hippospongia communis, S. officinalis adriatica and S. officinalis mollissima. These bath sponges showed an enhanced abundance in the eastern Cretan Sea (S. Aegean Sea. In addition, their dimensions, particularly height, increased with increasing depth. It is indicated that the hydrographic conditions prevailing in the eastern Cretan Sea affected the repopulating processes of sponge banks. In each species, the biometric characteristics of the experimental specimens were similar to those of the sponges found in the market and harvested at respective depths prior to the appearance of sponge disease.

  5. Recovery of the commercial sponges in the central and southeastern Aegean Sea (NE Mediterranean after an outbreak of sponge disease

    Directory of Open Access Journals (Sweden)

    J. CASTRITSI-CATHARIOS

    2012-12-01

    Full Text Available The distribution and biometry of commercial sponges (Porifera in coastal areas of the central and southeastern Aegean Sea was investigated to estimate the recovery progress of the populations eight years after the first appearance of sponge disease. Signs of the disease were detected only in 1.6% of the harvested sponges. Multivariate analysis on the percentage abundance of sponges showed two distinct groups among the sixteen fishing grounds studied: the eight deep (50-110 m and the eight shallow ones (<40 m. The group from the deep depths consisted of Spongia officinalis adriatica, S. agaricina and S. zimocca. The infralittoral zone was characterized by the presence of Hippospongia communis, S. officinalis adriatica and S. officinalis mollissima. These bath sponges showed an enhanced abundance in the eastern Cretan Sea (S. Aegean Sea. In addition, their dimensions, particularly height, increased with increasing depth. It is indicated that the hydrographic conditions prevailing in the eastern Cretan Sea affected the repopulating processes of sponge banks. In each species, the biometric characteristics of the experimental specimens were similar to those of the sponges found in the market and harvested at respective depths prior to the appearance of sponge disease.

  6. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from METEOR in the Adriatic Sea, Aegean Sea and others from 2011-04-05 to 2011-04-28 (NODC Accession 0108079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108079 includes discrete sample and profile data collected from METEOR in the Adriatic Sea, Aegean Sea, Alboran Sea, Ionian Sea, Mediterranean Sea,...

  7. Variability of mesozooplankton spatial distribution in the North Aegean Sea, as influenced by the Black Sea waters outflow

    Science.gov (United States)

    Siokou-Frangou, Ioanna; Zervoudaki, Soultana; Christou, Epaminondas D.; Zervakis, Vassilis; Georgopoulos, Dimitrios

    2009-11-01

    The North Aegean Sea constitutes an important region of the Mediterranean Sea since in its eastern part the mesotrophic, low salinity and relatively cold water from the Black Sea (outflowing from the Dardanelles strait) meets the oligotrophic, warm and very saline water of Levantine origin, thus forming a thermohaline front. Mesozooplankton samples were collected at discrete layers according to the hydrology of the upper 100 m, during May 1997 and September 1998. In May highest biomass and abundance values (up to 66.82 mg m - 3 and 14,157 ind m - 3 ) were detected in the 10-20 m layer (within the halocline) of the stations positioned close to the Dardanelles strait. The front moved slightly southwards in September, characterized by high biomass and abundance values within the halocline layer. The areas moderately or non influenced by Black Sea water revealed lower standing stock values than the frontal area in both cruises and maxima were detected in the uppermost low salinity layer. Samples collected at the stations and/or layers more influenced by Black Sea water were distinguished from those collected at layers and/or stations more affected by Levantine waters in both periods. In May the former samples were characterized by the copepods Acartia clausi, Centropages typicus, Paracalanus parvus. The abundance of the above species decreased gradually with increasing salinity, in the horizontal and/or in the vertical dimension, with a parallel increase of the copepods Oithona plumifera, Oithona copepodites, Oncaea media, Ctenocalanus vanus, Farranula rostrata. During September the frontal area as well as that covered by the modified Black Sea water, were highly dominated by the cladoceran Penilia avirostris and doliolids. For both seasons, MDS plots, issued from the combination of mesozooplankton and water-type data, revealed the gradual differentiation of zooplankton composition from the frontal area towards the area covered by Levantine water, following the

  8. Possible interrelation between the lead time of precursory seismic electric signals (SES and geodynamics in Aegean Sea

    Directory of Open Access Journals (Sweden)

    E. Dologlou

    2011-06-01

    Full Text Available The seismicity of the last 15 years in the Aegean Sea revealed that earthquakes (Mw > 5 with epicentres falling within the Sporades basin and the confined area north of Samos island were preceded by electric seismic signals (SES with a remarkably long lead time. A possible explanation of this behaviour by means of specific tectonics and geodynamics which characterise these two regions, such as a significant small crustal thickness and a high heat flow rate, has been attempted. New data seem to strengthen the above hypothesis.

  9. On the deep water masses outflow in the Aegean Sea: a pre- and post-EMT analysis

    Science.gov (United States)

    Bellacicco, Marco; Falcini, Federico; Salusti, Ettore

    2017-04-01

    In the last decades, the Aegean Sea (AS) has drawn attention and interest from the oceanographic community about the role that this sea has played in the Eastern Mediterranean Transient (EMT), with the key result of a "new" deep-water formation site in the eastern Mediterranean basin. This deep-water formation was due to different reasons: i) water budget anomalies that increased salinity of the surface and intermediate water masses; ii) the enters of these waters in the AS from Eastern Mediterranean Sea thought the Cretan Straits, and iii) episodes of strong winter cooling. Here, we explore the importance of deep water masses outflow from Aegean Sea throughout the Cretan Sea into the oriental basin of the Mediterranean Sea, in relation to last recent studies, focusing on the EMT event and its time table. To such goal we use all available, in situ, hydrologic data collected in the period 1985-1999, by trying to describe the outflow of the deep-water masses in the Levantine basin. Preliminary results revealed that the main source of dense water was beween Samarcande and its northern coast while the entrance of dense water in the Cyclades Plateau was essentially a flow between the Islands of Euboea and Andros, confirming what found by Bellacicco et al. (2016) from numerical results and marine geological evidences. The new analysis, moreover, points out the presence of a dense water mass debouching in the Levantine from the Cretean Sea during the spring time (i.e., maximum mixing period)of 1986-1988.Our results may allow to open new research question on the actual EMT timing and triggering, also considering theoretical model analyses (Smith 1975, Bellacicco et al., 2016).

  10. Macrophthalmus graeffei A. Milne Edwards, 1873 (Crustacea: Brachyura: Macrophthalmidae: a new Indo-Pacific guest off Rhodes Island (SE Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    M.A. PANCUCCI-PAPADOPOULOU

    2012-12-01

    Full Text Available A new alien crab, the macrophthalmid Macrophthalmus graeffei, is reported from the eastern coastline of Rhodes Island. The species, of Indo-West Pacific origin, is known from muddy sediments up to about 80 m depth. In the Mediterranean, its presence has been observed along Levantine coasts as well as along the Turkish coast of the Aegean Sea.Macrophthalmus graeffei increases to twelve the number of alien brachyurans present in the Hellenic SE Aegean Sea, ten of them having Indo-Pacific origin.

  11. Carbon dioxide, temperature, salinity, wind speed, air temperature, and atmospheric pressure collected via surface underway survey from R/V Aegaeo in Aegean Sea from February 8, 2006 to February 13, 2006 (NODC Accession 0084543)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0084543 includes chemical, meteorological, and physical underway data collected aboard the AEGAEO in Aegean Sea, and Mediterranean Sea from 8 February...

  12. Distribution of natural radionuclide concentrations in sediment samples in Didim and Izmir Bay (Aegean Sea-Turkey).

    Science.gov (United States)

    Aközcan, S

    2012-10-01

    Natural and artificial radionuclide pollutants of the marine environment have been recognized as a serious environmental concern. The natural radioactivity activity concentrations of (226)Ra, (238)U, (232)Th and (40)K were measured by gamma spectrometry in sediment samples collected from two different areas in Aegean Sea Turkish Coast. There is no information about radioactivity level in the study areas sediments so far. The results showed that the concentrations of activity in the sediment samples are 9 ± 0.6 Bq kg(-1)-12 ± 0.7 Bq kg(-1), 7 ± 0.4 Bq kg(-1)-16 ± 1.0 Bq kg(-1), 6 ± 0.3 Bq kg(-1)-16 ± 1.0 Bq kg(-1) and 250 ± 13 Bq kg(-1)-665 ± 33 Bq kg(-1) for (226)Ra, (238)U, (232)Th and (40)K, respectively. In general, the distribution of activity concentrations along the coast of the Aegean Sea area were in the same order as international levels.

  13. Geodynamic features along the Christianna-Santorini-Kolumbo tectonic line (South Aegean Sea, Greece)

    Science.gov (United States)

    Nomikou, Paraskevi; Papanikolaou, Dimitrios; Carey, Steve; Bejelou, Konstantina; Sakellariou, Dimitris; Kilias, Stefanos; Camilli, Rich; Escartin, Javier; Bell, Kathrine; Parks, Michelle

    2013-04-01

    Numerous oceanographic surveys have been conducted in Santorini Volcanic Group (South Aegean Sea) since 2001, revealing the spectacular morphology of the seafloor (multibeam data) and the sub-seafloor stratigraphic horizons (seismic profiles). Technological advancements in seafloor exploration such as ROVs and a submersible, enabled us to observe products of submarine volcanism that were previously inaccessible. In addition, gravity and box coring, geological and biological samples have been collected from selected areas for further analysis. The offshore geophysical survey in Santorini shows that recent volcanism occurred along a NE-SW tectonic zone named as Christianna-Santorini-Kolumbo (CSK) line. Christiana islets and three newly discovered submarine volcanic domes, with small colonies of yellow, presumably sulfur-reducing hydrothermal bacteria, occur in the southwestern part of the line. The presently active intra caldera volcanic domes of Palea and Nea Kameni islands and the low temperature (17-24°C) vent mounds covered by yellowish bacterial mat occupy the middle part of the line. The Santorini vent field is linked with the Kolumbo normal fault onshore which is likely controlling the pathways of hydrothermal circulation within the caldera. The most prominent feature at the NE part of this zone, is Kolumbo submarine volcanic chain which is extended 20Km with several volcanic domes aligned along this direction. The Kolumbo volcano had an explosive eruption in 1650 that killed 70 people on Santorini. The hydrothermal vent field in the crater floor of Kolumbo consists dominantly of active and inactive sulfide-sulfate structures in the form of vertical spires and pinnacles, mounds and flanges along a NE-SW trend, with temperatures up to 220°C and vigorous CO2 gas emission. For several years, the highest frequency of earthquakes was concentrated mainly in the vicinity of Kolumbo volcano. However, during 2011-2012 both seismic and geodetic unrest began abruptly

  14. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from Marcus G. Langseth in the Aegean Sea, Alboran Sea and others from 2015-04-13 to 2015-11-12 (NCEI Accession 0144534)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144534 includes Surface underway data collected from Marcus G. Langseth in the Aegean Sea, Alboran Sea, Mediterranean Sea, Mediterranean Sea -...

  15. Assessment of offshore wind power potential in the Aegean and Ionian Seas based on high-resolution hindcast model results

    Directory of Open Access Journals (Sweden)

    Takvor Soukissian

    2017-03-01

    Full Text Available In this study long-term wind data obtained from high-resolution hindcast simulations is used to analytically assess offshore wind power potential in the Aegean and Ionian Seas and provide wind climate and wind power potential characteristics at selected locations, where offshore wind farms are at the concept/planning phase. After ensuring the good model performance through detailed validation against buoy measurements, offshore wind speed and wind direction at 10 m above sea level are statistically analyzed on the annual and seasonal time scale. The spatial distribution of the mean wind speed and wind direction are provided in the appropriate time scales, along with the mean annual and the inter-annual variability; these statistical quantities are useful in the offshore wind energy sector as regards the preliminary identification of favorable sites for exploitation of offshore wind energy. Moreover, the offshore wind power potential and its variability are also estimated at 80 m height above sea level. The obtained results reveal that there are specific areas in the central and the eastern Aegean Sea that combine intense annual winds with low variability; the annual offshore wind power potential in these areas reach values close to 900 W/m2, suggesting that a detailed assessment of offshore wind energy would be worth noticing and could lead in attractive investments. Furthermore, as a rough estimate of the availability factor, the equiprobable contours of the event [4 m/s ≤ wind speed ≤ 25 m/s] are also estimated and presented. The selected lower and upper bounds of wind speed correspond to typical cut-in and cut-out wind speed thresholds, respectively, for commercial offshore wind turbines. Finally, for seven offshore wind farms that are at the concept/planning phase the main wind climate and wind power density characteristics are also provided.

  16. Source parameters of the M 6.5 Skyros Island (North Aegean Sea earthquake of July 26, 2001

    Directory of Open Access Journals (Sweden)

    A. Kiratzi

    2002-06-01

    Full Text Available Teleseismic body wave modelling, time domain moment tensor inversion of regional waveforms and spectral analysis of the far-field P-wave pulses are used to derive the source parameters of the July 26, 2001 Skyros earthquake (M 6.5. Its epicentre is located south of the Sporades Islands in the North Aegean Sea (Greece. Previous focal mechanism solutions indicate motion on strike-slip faults. The time domain moment tensor inversion is applied for the first time to the regional waveforms of the recently established broadband network in Greece. Its application gave results which are highly consistent with teleseismic waveform modelling. The results of this study, in combination with the distribution of aftershocks, indicate left-lateral strike slip motion on a NW-SE striking fault with parameters: fault plane (strike = 151°, dip = 83°, rake = 7° and auxiliary plane (strike = 60°, dip = 84°, rake = 173°, depth 12 km and M 0 = 5.98e18 N m. Moreover, the time domain moment tensor inversion technique yielded a pure double couple source with negligible CLVD. The spectral analysis of the far-field P-wave pulses resulted in a fault length L ~ 32 km, stress drop ~ 9 bars and average displacement u ~ 30 cm.These values are in very good agreement with those estimated from empirical scaling relations applicable to the Aegean area.

  17. Living benthic foraminifera as an environmental proxy in coastal ecosystems: A case study from the Aegean Sea (Greece, NE Mediterranean)

    Science.gov (United States)

    Koukousioura, Olga; Dimiza, Margarita D.; Triantaphyllou, Maria V.; Hallock, Pamela

    2011-12-01

    The species composition of the epiphytic benthic foraminiferal fauna was compared at two coastal locations in the Aegean Sea. Samples were collected during August 2001 and July 2003 along the southeastern coast of Andros Island at Korthi Gulf, where there are minimal anthropogenic activities, and at Kastro Gulf, with substantial anthropogenic influence. This study represents the first application of the FORAM Index (FI), which is a single-metric index for water quality originally developed for western Atlantic reef foraminiferal assemblages, to Mediterranean assemblages. Multivariate analyses distinguished three clusters of sample sites representing three foraminiferal assemblages. Samples dominated by the mixotrophic species, A. lobifera, were collected primarily from sites along the northern coasts of both gulfs. Characteristics of this assemblage, including relatively high dominance (D = 0.27-0.51), lower Shannon-Wiener diversity (H' = 1.3-2.1) and high FI (6.6-8.2), all reflect oligotrophic environmental conditions typical of pristine waters of the Aegean Sea. A. lobifera was typically the most common species in the second assemblage, though relative abundances of heterotrophic taxa were higher, resulting in somewhat higher diversity (H' = 1.6-2.4) and lower dominance (D = 0.14-0.36). These indices, as well as the FI range of 3.5-7.0 indicated somewhat more prevalent organic carbon resources but still relatively high water quality. This assemblage was found along the southern coast of Korthi Gulf and at more interior sites in northern Kastro Gulf. The third assemblage was dominated by smaller heterotrophic species, including notable proportions of the stress-tolerant taxa Ammonia spp. and Elphidium spp., and had few or no A. lobifera. Diversity (H' = 1.4-2.0) and dominance (D = 0.22-0.47) indices were similar to those for the first assemblage, but FI values were much lower (2.0-3.4). Samples characterized by this assemblage were collected only from the southern

  18. Two experimental fish aggregating systems (fads in the Aegean sea: their design and application

    Directory of Open Access Journals (Sweden)

    Aytaç Özgül

    2011-01-01

    Full Text Available Two steel spar buoys were constructed and moored in 50 and 100 m deep of water in the Aegean Sea to support recreational fisheries. The first FAD was deployed at coordinates 38°01´48´´N 26°58´02´´E and at a distance of 3 nautical miles from the shoreline. The other FAD was moored at 1.1 nautical miles from the shoreline at coordinates 38°03´11´´N; 26°59´01´´E. An anchor (1.2x1.2x0.8 m3 weighing approximate 2.76 metric ton, made of reinforced concrete, was used to hold a FAD weighing approximate 1.5 metric ton. Hardware and connections of FADs, ropes, mooring calculation and anchor design were made. The interaction between the forces of wave and current and FADs in those waters was investigated. In the experiment, all forces (drag force, buoyancy force etc. acting on FADs were calculated. It is proposed that the construction of the FADs should take the following design criteria into consideration: wave and current, forces related to the FADs, deployment depth, mooring hardware and ropes. This knowledge provides an important reference for stakeholders performing projects aiming to increase the performance and service life FADs.Duas bóias de aço spar foram construídas e ancoradas em 50 e 100 m de profundidade nas águas do Mar Egeu para dar apoio à pesca recreativa. O primeiro FAD foi implantado nas coordenadas 38°01'48''N 26°58'02''E, a uma distância de 3 milhas náuticas da costa. O outro ficou ancorado a 1,1 milha náutica da costa nas coordenadas 38°03'11''N; 26°59'01''E. Uma âncora (1.2x1.2x0.8 m3, pesando aproximadamente 2,76 toneladas, feita de concreto armado, foi usada para prender um FAD de peso aproximado de 1,5 toneladas. Foram realizados cálculos para determinação das conexões dos FADs, dos cabos e da ancoragem. A interação entre as forças de ondas e correntes com os FADs foi também investigada. No experimento, todas as forças (força de arrasto, força de empuxo, etc atuantes sobre os FADs foram

  19. Setting an ecological baseline prior to the bottom-up establishment of a marine protected area in Santorini Island, Aegean Sea

    OpenAIRE

    M. SALOMIDI; S. GIAKOUMI; V. GERAKARIS; Y. ISSARIS; Sini, M.; K. TSIAMIS

    2016-01-01

    Since 2010, a bottom-up initiative has been launched in Santorini Island (Aegean Sea, Eastern Mediterranean) for the establishment of the first fully protected marine protected area in the Cyclades, aiming at improving fisheries and enhancing responsible recreational uses at sea. Following discussions with local small-scale fishermen and divers, two sites along the southern and south-eastern coasts of the island were suggested as suitable to this end. In 2012, a baseline study was conducted i...

  20. diet composition of the salamander lyciasalamandra luschani basoglui on the greek island of kastellorizo in the southeast aegean sea

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    the diet composition of the lycian salamander lyciasalamandra luschani basoglui across both age and sex groups was studied.specimens were collected from a small island in the southeast aegean sea.the dominant prey group of juveniles consisted of collembola,while coleoptera dominated the diet of males and females.the number and size of prey items consumed by males and females of l.luschani basoglui were quite similar,while juveniles ate fewer items of much smaller size.the numerical abundance along with the four measures of the size of prey permitted discrimination among males,females and juveniles.although discrimination between adults and juveniles is expected due to dissimilarity in body size,discrimination between males and females remains inexplicable despite their similarity in body size.future studies should be focused on understanding how and why prey choice differs between sexes in l.luschani basoglui.

  1. Concentration factors of radionuclides and trace metals in Mytilus galloprovincialis in an estuarine ecosystem - North Aegean Sea - Greece

    Energy Technology Data Exchange (ETDEWEB)

    Florou, H.; Catsiki, A.B.; Papaefthymiou, H.; Chaloulou, Ch. [NCSR Demokritos, INT-RP, Environmental Radioactivity Lab., Athens (Greece)

    2004-07-01

    Mussels are worldwide recognized as pollution bio-indicator organisms (Mussel watch program of CIESM) because they accumulate pollutants in their tissues at elevated levels in terms of biological availability in the marine environment. In the present study, the levels of {sup 137}Cs, Cr, Cu, Mn and Zn were measured in Mytilus galloprovincialis caught from Thermaikos gulf in North Aegean Sea Greece. The samples were collected seasonally from two aqua-cultures during the period 2000 2003. Measured and published concentrations of the above elements in seawater were used for the evaluation of concentration factors by applying a linear and a non-linear regression analysis. The variation in between the two stations and the seasonal evolution of bioaccumulation of the examined elements was also investigated. Some data on the concentrations of the measured elements in sediments from the area considered were evaluated as for determining the pollution conditions of the organism habitat. (author)

  2. Integrated energy balance analysis of a stand-alone wind power system for various typical Aegean Sea regions

    Science.gov (United States)

    Kaldellis, J. K.; Tsesmelis, M.

    2002-01-01

    The wind power industry is nowadays a mature energy production sector disposing to market commercial wind converters from 50 W up to 5 MW. In the present work the possibility of using stand-alone electricity production systems based on a small wind turbine in order to meet the electricity requirements of remote consumers is analysed for selected Aegean Sea regions possessing representative wind potential types. The proposed configuration results from an extensive long-term meteorological data analysis on a no-load rejection condition basis during the entire time period examined. Accordingly, an integrated energy balance analysis is carried out for the whole time period investigated, including also the system battery depth-of-discharge distribution versus time. Finally, the predicted optimum system configuration is compared to other existing technoeconomic alternatives on a simplified total production cost basis. The results support the viability of similar solutions, especially for areas of high or medium wind potential.

  3. Integrated energy balance analysis of a stand-alone wind power system for various typical Aegean Sea regions

    Energy Technology Data Exchange (ETDEWEB)

    Kaldellis, J.K.; Tsesmelis, M. [TEI Piraeus, Hellinico (Greece). Mechanical Engineering Dept.

    2002-07-01

    The wind power industry is nowadays a mature energy production sector disposing to market commercial wind converters from 50 W up to 5 MW. In the present work the possibility of using stand-alone electricity production systems based on a small wind turbine in order to meet the electricity requirements of remote consumers is analysed for selected Aegean Sea regions possessing representative wind potential types. The proposed configuration results from an extensive long-term meteorological data analysis on a no-load rejection condition basis during the entire time period examined. Accordingly, an integrated energy balance analysis is carried out for the whole time period investigated, including also the system battery depth-of-discharge distribution versus time. Finally, the predicted optimum system configuration is compared to other existing technoeconomic alternatives on a simplified total production cost basis. The results support the viability of similar solutions, especially for areas of high or medium wind potential. (author)

  4. Air and seawater pollution and air-sea gas exchange of persistent toxic substances in the Aegean Sea: spatial trends of PAHs, PCBs, OCPs and PBDEs.

    Science.gov (United States)

    Lammel, Gerhard; Audy, Ondřej; Besis, Athanasios; Efstathiou, Christos; Eleftheriadis, Kostas; Kohoutek, Jiři; Kukučka, Petr; Mulder, Marie D; Přibylová, Petra; Prokeš, Roman; Rusina, Tatsiana P; Samara, Constantini; Sofuoglu, Aysun; Sofuoglu, Sait C; Taşdemir, Yücel; Vassilatou, Vassiliki; Voutsa, Dimitra; Vrana, Branislav

    2015-08-01

    Near-ground air (26 substances) and surface seawater (55 substances) concentrations of persistent toxic substances (PTS) were determined in July 2012 in a coordinated and coherent way around the Aegean Sea based on passive air (10 sites in 5 areas) and water (4 sites in 2 areas) sampling. The direction of air-sea exchange was determined for 18 PTS. Identical samplers were deployed at all sites and were analysed at one laboratory. hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs) as well as dichlorodiphenyltrichloroethane (DDT) and its degradation products are evenly distributed in the air of the whole region. Air concentrations of p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and o,p'-DDT and seawater concentrations of p,p'-DDE and p,p'-DDD were elevated in Thermaikos Gulf, northwestern Aegean Sea. The polychlorinated biphenyl (PCB) congener pattern in air is identical throughout the region, while polybrominated diphenylether (PBDE)patterns are obviously dissimilar between Greece and Turkey. Various pollutants, polycyclic aromatic hydrocarbons (PAHs), PCBs, DDE, and penta- and hexachlorobenzene are found close to phase equilibrium or net-volatilisational (upward flux), similarly at a remote site (on Crete) and in the more polluted Thermaikos Gulf. The results suggest that effective passive air sampling volumes may not be representative across sites when PAHs significantly partitioning to the particulate phase are included.

  5. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from METEOR in the Aegean Sea, Mediterranean Sea and others from 2001-10-18 to 2001-11-11 (NODC Accession 0084620)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0084620 includes discrete sample and profile data collected from METEOR in the Aegean Sea, Mediterranean Sea, Mediterranean Sea - Eastern Basin,...

  6. PH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from PROFESSOR SIEDLECKI in the Adriatic Sea, Aegean Sea and others from 1988-11-17 to 1988-11-26 (NCEI Accession 0144306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144306 includes discrete sample and profile data collected from PROFESSOR SIEDLECKI in the Adriatic Sea, Aegean Sea, Mediterranean Sea, Mediterranean...

  7. Dissolved inorganic carbon, alkalinity, temperature, salinity and OXYGEN - APPARENT UTILIZATION (AOU) collected from discrete sample and profile observations using CTD, bottle and other instruments from UNKNOWN PLATFORMS in the Adriatic Sea, Aegean Sea and others from 1874-10-11 to 2000-04-26 (NODC Accession 0117350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117350 includes chemical, discrete sample, physical and profile data collected from UNKNOWN PLATFORMS in the Adriatic Sea, Aegean Sea, Alboran Sea,...

  8. Activation of the operational ecohydrodynamic model (3D CEMBS - the ecosystem module

    Directory of Open Access Journals (Sweden)

    Jaromir Jakacki

    2013-08-01

    Full Text Available The paper describes the ecohydrodynamic predictive model - the ecosystem module - for assessing the state of the Baltic marine environment and the Baltic ecosystem. The Baltic Sea model 3D CEMBS (the Coupled Ecosystem Model of the Baltic Sea is based on the Community Earth System Model, which was adopted for the Baltic Sea as a coupled sea-ice-ecosystem model. The 3D CEMBS model uses: (i hydrodynamic equations describing water movement, (ii thermodynamic equations, (iii equations describing the concentration distribution of chemical variables in the sea, and (iv equations describing the exchange of matter between individual groups of organisms and their environment that make allowance for the kinetics of biochemical processes. The ecosystem model consists of 11 main components: three classes of phytoplankton (small phytoplankton, large phytoplankton represented mainly by diatoms and summer species, mostly cyanobacteria expressed in units of carbon and chlorophyll a as separate variables, zooplankton, pelagic detritus, dissolved oxygen and nutrients (nitrate, ammonium, phosphate and silicate. In operational mode, 48-hour atmospheric forecasts provided by the UM model from the Interdisciplinary Centre for Mathematical and Computational Modelling of Warsaw University (ICM are used. All model forecasts are available on the website http://deep.iopan.gda.pl/CEMBaltic/new_lay/index.php. The results presented in this paper show that the 3D CEMBS model is operating correctly.

  9. Foraminifera eco-biostratigraphy of the southern Evoikos outer shelf, central Aegean Sea, during MIS 5 to present

    Science.gov (United States)

    Drinia, Hara; Antonarakou, Assimina; Tsourou, Theodora; Kontakiotis, George; Psychogiou, Maria; Anastasakis, George

    2016-09-01

    The South Evoikos Basin is a marginal basin in the Aegean Sea which receives little terrigenous supply and its sedimentation is dominated by hemipelagic processes. Late Quaternary benthic and planktonic foraminifera from core PAG-155 are investigated in order to understand their response to the glacial-interglacial cycles in this region. The quantitative analysis of planktonic foraminifera, coupled with accelerator mass spectrometry (14C-AMS) radiocarbon date measurements, provide an integrated chrono-stratigraphic time framework over the last 90 ka (time interval between late Marine Isotopic Stages 5 and 1; MIS5-MIS1). The temporary appearance and disappearance as well as several abundance peaks in the quantitative distribution of selected climate-sensitive planktonic species allowed the identification of several eco-bioevents, useful to accurately mark the boundaries of the eco-biozones widely recognized in the Mediterranean records and used for large-scale correlations. The established bio-ecozonation scheme allows a detailed palaecological reconstruction for the late Pleistocene archive in the central Aegean, and furthermore provides a notable contribution for palaeoclimatic studies, facilitating intercorrelations between various oceanographic basins. The quantitative analyses of benthic foraminifera identify four distinct assemblages, namely Biofacies: Elphidium spp., Haynesina spp. Biofacies, characterized by neritic species, dominated during the transition from MIS 5 to MIS 4; Cassidulina laevigata/carinata Biofacies dominated till 42 ka (transgressive trend from MIS 4 to MIS 3); Bulimina gibba Biofacies dominated from 42 ka to 9.5 ka (extensive regression MIS 3,2 through lowstand and early transgression; beginning of MIS 1); Bulimina marginata, Uvigerina spp. Biofacies dominated from 9.5 ka to the present (late transgression through early highstand; MIS 1)., This study showed that the South Evoikos Basin which is characterized by its critical depths and

  10. 1881 and 1949 earthquakes at the Chios-Cesme Strait (Aegean Sea and their relation to tsunamis

    Directory of Open Access Journals (Sweden)

    Y. Altinok

    2005-01-01

    Full Text Available The most earthquake-prone areas in the eastern central Aegean Sea are the Izmir Bay, the Karaburun peninsula and the island of Chios. The level of seismic activity and tsunami potential are influenced by the presence of normal faults around the region. There have been about 20 moderate-size earthquakes from 496 BC to 1949 AD. Among these earthquakes, the ones on the dates 20 March 1389, 13 November 1856, 19/22 January 1866, 3 April 1881 and 23 July 1949 produced tsunamis. The Chios-Cesme earthquake (1881, Mw 6.5 took place in the South of the Cesme strait while the Chios-Karaburun earthquake (1949, Mw 6.7 occurred in the North. The tsunamis caused by the earthquakes affected the coasts of Chios Island and Cesme. These waves are thought to be associated with the earthquakes and co-seismic underwater failures possibly occurred along the coasts of the Chios Island and Karaburun Peninsula or on the complex subaqueous morphology between these lands. Some sea waves or oscillations observed following the aftershocks are believed to be related to other natural phenomena; e.g. the seiches occurred mainly in open-narrow bays as triggered by the earthquakes.

  11. Climatic variability of the sub-surface sea temperatures in the Aegean-Black Sea system and relation to meteorological forcing

    Energy Technology Data Exchange (ETDEWEB)

    Kontoyiannis, H.; Papadopoulos, V.; Georgopoulos, D. [Hellenic Center for Marine Research, Attica (Greece); Kazmin, A.; Zatsepin, A. [P.P. Shirshov Institute of Oceanography, Moscow (Russian Federation)

    2012-09-15

    Non-smoothed yearly temperature records with minimal statistical uncertainties are constructed for winter and summer of the period 1950-2000 in two areas in the Aegean Sea, for the sub-surface layer of 80-120 m, and two areas in the Black Sea, for the sub-surface layer of sigma-theta isopycnals between 14.5 and 15.4. The specific areas are selected mostly because of the dense hydrographic-data coverage they have during the period 1950-2000. Two trend regimes appear in both Seas: a period of decreasing sea temperatures from the early/mid 1960s to the early/mid 1990s and an apparent warming afterwards. Trends in sea temperatures correlate with trends in the North Atlantic Oscillation (NAO) and partly the East Atlantic West Russian (EAWR) indexes, but the signs of NAO and/or EAWR cannot sufficiently justify the winter-to-winter temperature changes in the entire study area. In examining the wind flows in the sea-level-pressure maps for characteristic winters in which local peaks in the sea-temperature records occur, we identify particular sea-level-pressure structures that are not accounted for by the typical North-Atlantic or East Atlantic-West Russia positive or negative dipoles. In addition, there are winters when the Siberian High induces local maxima in sea-temperatures in the study area. A spectral-coherence analysis of the unfiltered winter sea-temperature and the corresponding teleconnection NAO/EAWR records, shows that common spectral and coherence peaks exist at {proportional_to}5-6, {proportional_to}9-10 and {proportional_to}15-17 years. (orig.)

  12. Climatic variability of the sub-surface sea temperatures in the Aegean-Black Sea system and relation to meteorological forcing

    Science.gov (United States)

    Kontoyiannis, H.; Papadopoulos, V.; Kazmin, A.; Zatsepin, A.; Georgopoulos, D.

    2012-09-01

    Non-smoothed yearly temperature records with minimal statistical uncertainties are constructed for winter and summer of the period 1950-2000 in two areas in the Aegean Sea, for the sub-surface layer of 80-120 m, and two areas in the Black Sea, for the sub-surface layer of sigma-theta isopycnals between 14.5 and 15.4. The specific areas are selected mostly because of the dense hydrographic-data coverage they have during the period 1950-2000. Two trend regimes appear in both Seas: a period of decreasing sea temperatures from the early/mid 1960s to the early/mid 1990s and an apparent warming afterwards. Trends in sea temperatures correlate with trends in the North Atlantic Oscillation (NAO) and partly the East Atlantic West Russian (EAWR) indexes, but the signs of NAO and/or EAWR cannot sufficiently justify the winter-to-winter temperature changes in the entire study area. In examining the wind flows in the sea-level-pressure maps for characteristic winters in which local peaks in the sea-temperature records occur, we identify particular sea-level-pressure structures that are not accounted for by the typical North-Atlantic or East Atlantic-West Russia positive or negative dipoles. In addition, there are winters when the Siberian High induces local maxima in sea-temperatures in the study area. A spectral-coherence analysis of the unfiltered winter sea-temperature and the corresponding teleconnection NAO/EAWR records, shows that common spectral and coherence peaks exist at ~5-6, ~9-10 and ~15-17 years.

  13. Variations in fault-slip data and cooling history reveal corridor of heterogeneous backarc extension in the eastern Aegean Sea region

    Science.gov (United States)

    Ring, Uwe; Gessner, Klaus; Thomson, Stuart

    2017-03-01

    We report fault-slip data across the boundary between the highly extended and largely submerged crust underlying the Aegean Sea from Samos in the north to eastern Crete in the south, and the much less extended and emergent crust of western Anatolia. We identify three brittle deformation increments, a late Miocene (mainly Pliocene) to Recent crustal stretching increment, an intermittent early to late Miocene shortening increment concurrent with extension and magmatism, and a Miocene extensional event. The youngest increment documents late Miocene to Recent NNE extension over large areas, but can locally also be oriented SE (Amorgos and Astipalea Islands), and ESE (eastern Crete) suggesting overall oblate strain geometry. The intermittent Miocene ( 24-5 Ma) fault-slip records suggest overall prolate strain geometry, where NNE stretching is accompanied by E-W shortening. The older extension event is mainly NNE directed but on Samos Island extension is E-W, probably reflecting local extension in a sinistral wrench corridor in the early/mid Miocene. Overall it seems that since the early Miocene NNE-trending extension is the dominant regime in the eastern Aegean with an intermittent component of short-lived E-W shortening. The existence of a corridor of heterogeneous crustal deformation - which is spatially associated with uncharacteristically old fission track ages - and the apparent change in strain geometry in time challenge concepts that propose that the eastern Aegean Sea and western Anatolia have been deformed as a continuous tectonic domain since the Miocene. We propose that the regional variation in extensional strain geometry resulted from a sinistral wrench component that was superimposed on the regional 'background' NNE extension by translation across a diffuse plate boundary. We conclude that the eastern shoreline of the Aegean Sea is controlled by a Miocene to Recent sinistral wrench corridor that accommodated movement between different lithospheric domains.

  14. Particular ceramic forms in the central Balkan and northern shores of the Aegean sea in the late bronze age

    Directory of Open Access Journals (Sweden)

    Bulatović Aleksandar

    2011-01-01

    Full Text Available This paper deals with the appearance and development of particular ceramic forms that were prevalent on the wider territory from the lower Danube to the northern shores of the Aegean sea during the middle and Late Bronze Age. These forms relate to globular beakers, pear shaped vessels with everted rims with arch shaped handles, cups with handles with plastic applications on their upper surface, etc. Particular attention is devoted to the phenomenon of globular beakers of the LBA in the valleys of Varder, Mesta and Struma rivers. All information collected primarily through analysis of stylistic-typological characteristics of ceramics of the middle and Late Bronze Age - that took into account ritual burials, layout of settlements, trade routes and climactic conditions during that period - points to population movements from the north to the south already by the LBA, i.e. in 15th century BC. These movements contributed to the creation of particular cultural groups in the LBA in the central Balkans, such as the Brnjica cultural group. However, these movements cannot be clearly linked to the so-called Aegean Migration, and for this reason their character and chronology are subject to debate. Ultimately it can be concluded that beakers of the Zimnicea -Cherkovna-Plovdiv type appeared in the late Bronze Age in the Vlasine depression and the Danube valley through the evolution of beaker forms of cultural groups of earlier periods. Almost contemporaneously, during LBA, a variant of this ceramic form, richly ornamented (mostly with spirals and similar in manner to the cultural group Dubovac-Žuto Brdo-Grla Mare- Krna, appeared in the LBA culture in northern Greece. Clearly this stylistic mannerism, with spirals as characteristic elements, spread relatively quickly through successive migrations in the period of 15th-14th century BC, toward the south of the Balkan Peninsula, thus covering the wider territory from the southern tip of the Carpathian mountains

  15. Plio-Quaternary history of the Turkish coastal zone of the Enez-Evros Delta: NE Aegean Sea

    Directory of Open Access Journals (Sweden)

    B. ALPAR

    2001-12-01

    Full Text Available The Enez-Evros Delta, NE Aegean Sea, is located in one the most important wetlands in the world with its sandy offshore islands, abandoned channel mouths, sand-dunes, shoals, marshlands, saline lagoons and saltpans. It comprises very well developed sedimentary units and a prodelta lying on an older submarine delta. The present day elevations of the middle-late Pleistocene marine terraces indicate a regional tectonic uplift in the area. Due to lack of geophysical and bore hole data and partly due to its strategic position, the structural and stratigraphic features of the submarine extension of the delta are not known in detail. In this paper, Plio-Quaternary history of this delta and its submarine part on the Turkish shelf was explored by using high-resolution shallow reflection seismic profiles. The delta is formed by the alluvial deposits of the Enez-Evros River and shaped by their interaction with the sea. It takes place in front of a large and protected ancient bay which was filled rapidly over millennia. The sediments in the plateau off the river are principally pro-deltaic with muddy areas near the river mouths changing to muddy sand further out. The sea-level changes in Plio-Quaternary were characterised by three different seismic stratigraphic units on the folded Miocene limestone basement. In the late Pleistocene, the shelf area over an Upper Miocene basement was flooded during the Riss-Würm interglacial period, exposed in the Würm glacial stage, and flooded once again during the Holocene transgression.

  16. Diet and trophic level of the longnose spurdog Squalus blainville (Risso, 1826) in the deep waters of the Aegean Sea

    Science.gov (United States)

    Kousteni, Vasiliki; Karachle, Paraskevi K.; Megalofonou, Persefoni

    2017-06-01

    Knowledge of the diet and trophic level of marine predators is essential to develop an understanding of their ecological role in ecosystems. Research conducted on the trophic ecology of the deep-sea sharks is rather limited. The purpose of this study was to examine the diet of the longnose spurdog Squalus blainville, a deep-sea shark categorized as ;data deficient; within its distribution range, with respect to sex, maturity, age, season and sampling location. The stomach contents of 211 specimens, captured in the Aegean (off Skyros and the Cyclades Islands) and Cretan Seas, using commercial bottom-trawlers from 2005 to 2012, were analysed. The cumulative prey curve showed that the sample size was adequate to describe the species' diet. The identified prey items belonged to five major groups: Teleostei, Crustacea, Cephalopoda, Annelida and Phanerogams. Higher diet diversity was observed in females compared to males, in immature individuals compared to mature ones, regardless of sex, and in spring and winter compared to other seasons. Age and sampling location seemed to influence both the diet diversity and trophic spectrum of the species. Feeding intensity based on the vacuity index was not significantly influenced by any of the factors examined, while the stomach filling degree was significantly influenced by all factors, except sex, showing significantly higher values in mature females compared to immature ones, in older individuals, in autumn compared to winter, and a significantly lower value in the Cyclades Islands compared to other locations. Females showed a significant larger mouth length compared to males of the same length, while no between-sex differences were found in gut morphometrics. The estimated fractional trophic level (TROPH=4.41) classified the species as carnivore with a preference for Teleostei and Cephalopoda, confirming its high trophic position.

  17. Delimitation of the warm and cold period of the year based on the variation of the Aegean sea surface temperature

    Directory of Open Access Journals (Sweden)

    A. MAVRAKIS

    2012-12-01

    Full Text Available Knowledge of the warm and cold season onset is important for the living conditions and the occupational activities of the inhabitants of a given area, and especially for agriculture and tourism. This paper presents a way to estimate the onset/end of the cold and warm period of the year, based on the sinusoidal annual variation of the Sea Surface Temperature. The method was applied on data from 8 stations of the Hellenic Navy Hydrographic Service, covering the period from 1965-1995. The results showed that the warm period starts sometime between April 28th and May 21st while it ends between October 27th and November 19th in accordance with the findings of other studies. Characteristic of the nature of the parameter used is the very low variance per station – 15 days at maximum. The average date of warm period onset is statistically the same for the largest part of the Aegean, with only one differentiation, that between Kavala and the southern stations ( Thira and Heraklion.

  18. Increased diversity of sessile epibenthos at subtidal hydrothermal vents: seven hypotheses based on observations at Milos Island, Aegean Sea

    Directory of Open Access Journals (Sweden)

    Carlo Nike Bianchi

    2011-06-01

    Full Text Available Research on subtidal hydrothermal vent ecosystems at Milos, Hellenic Volcanic Arc (Aegean Sea, suggested that vent activity increased the species richness of sessile epibenthic assemblages. Based on 303 species found in 6 sites (3 close to vents, 3 farther away, the present paper uses correspondence analysis and species/samples curves to examine the species composition and richness of these assemblages. Differences due to vent proximity were more important than those due to bottom depth and distance from the shore. Diversity was confirmed to be higher near the vents, although none of the 266 species found at the vent sites can be considered as obligate vent-associated species. Seven different, although not mutually exclusive, hypotheses are discussed to explain the pattern of increased epibenthic species diversity at the vent sites, namely: (i vents represent an intermediate disturbance, inducing mortality by the emission of toxic fluids; (ii higher winter temperature allows for the occurrence of warm-water species, which add to the regional background; (iii venting disrupts the homogeneity of the water bottom layer, increasing bottom roughness and hence habitat heterogeneity; (iv deposition of minerals and enhanced bioconstruction by Ca enrichment increment habitat provision; (v fluid emission induces advective mechanisms that favour recruitment; (vi vents emit CO2, nutrients and trace elements that enhance primary productivity; and (vii bacterial chemosynthesis add to photosynthesis to provide a diversity of food sources for the fauna.

  19. Some aspects of the biology and ecology of Knipowitschia caucasica (Teleostei: Gobiidae) in the Evros Delta (North Aegean Sea)

    Science.gov (United States)

    Kevrekidis, T.; Kokkinakis, A. K.; Koukouras, A.

    1990-06-01

    Some aspects of the biology and ecology of the goby Knipowitschia caucasica were studied over a period of 13 months in a poly-to euhaline area in the Evros Delta (North Aegean Sea). This fish grows rapidly in the summer and autumn after hatching, matures after its first winter, breeds from the end of April to the end of July, and grows rapidly again in July September. The older males perish after their second February, whereas some females have a second breeding season at the end of April/beginning of May, shortly before their death. The fish grows to about 40 mm in total length. There is a positive correlation between the total length (TL) and the standard length (SL) or the cleaned body weight (CW). SL increases slower than TL, whereas CW increases slower than TL in immature individuals and faster in males and females. There is no difference between immature individuals, males and females, in the growth rate of SL, TL and CW, TL. The mean monthly values of the condition factor varies from 0.289 to 0.576 in females and from 0.313 to 0.548 in males. The overall sex ratio of females to males is 1: 1.46. Fecundity ranges from 60 to 217 eggs with a mean value of 109.8 and depends upon size, whereas relative fecundity varies between 968 and 2170 with a mean of 1558. The fish feeds predominantly on benthic amphipods and polychaetes.

  20. Assessing enigmatic boulder deposits in NE Aegean Sea: importance of historical sources as tool to support hydrodynamic equations

    Directory of Open Access Journals (Sweden)

    M. Vacchi

    2012-04-01

    Full Text Available Due to their importance in the assessment of coastal hazards, several studies have focused on geomorphological and sedimentological field evidence of catastrophic wave impacts related to historical tsunami events. Among them, many authors used boulder fields as important indicators of past tsunamis, especially in the Mediterranean Sea. The aim of this study was to understand the mechanism of deposition of clusters of large boulders, consisting of beachrock slabs, which were found on the southern coasts of Lesvos Island (NE Aegean Sea. Methods to infer the origin of boulder deposits (tsunami vs. storm wave are often based on hydrodynamic models even if different environmental complexities are difficult to be incorporated into numerical models. In this study, hydrodynamic equations did not provide unequivocal indication of the mechanism responsible for boulder deposition in the study area. Further analyses, ranging from geomorphologic to seismotectonic data, indicated a tsunami as the most likely cause of displacement of the boulders but still do not allow to totally exclude the extreme storm origin. Additional historical investigations (based on tsunami catalogues, historical photos and aged inhabitants interviews indicated that the boulders are likely to have been deposited by the tsunami triggered by the 6.7 Ms Chios-Karaburum earthquake of 1949 or, alternatively, by minor effects of the destructive tsunami produced by 1956's Amorgos Island earthquake. Results of this study point out that, at Mediterranean scale, to flank numerical models with the huge amount of the available historical data become a crucial tool in terms of prevention policies related to catastrophic coastal events.

  1. Hydrodynamic features of the South Aegean Sea as derived from Argo T/ S and dissolved oxygen profiles in the area

    Science.gov (United States)

    Kassis, Dimitris; Krasakopoulou, Evangelia; Korres, Gerasimos; Petihakis, George; Triantafyllou, George S.

    2016-11-01

    In this work, the hydrodynamic picture of the South Aegean Sea is examined through an analysis of recent measurements in its sub-basins, the Myrtoan and Cretan Sea. Both sub-basins play an important role in the water circulation, exchange, and formation processes that affect the dynamics of the whole Eastern Mediterranean. For the first time, Bio-Argo floats were deployed in the area under the Greek Argo Research Infrastructure coordination. The acquired profiles cover an almost 2-year period (November 2013-July 2015) and are compared with previous Argo profiles and the re-processed time-series data recorded from the E1-M3A POSEIDON observatory operating in the area since 2007. The spatio-temporal distribution of the physical and chemical properties in each sub-basin is examined. Dense water formation events are revealed in the northern part (Myrtoan), while the wider area can be characterized as pre-conditioned. In the Cretan basin, a strong inter-annual variability of the salinity field at intermediate and deep layers is observed that is associated with water exchange from its open boundaries. Furthermore, comparison of the dissolved oxygen (DO) distribution with physical water properties within both the mixed layer, and at greater depths, indicated that relatively high but still under-saturated DO values are more likely to be associated with convection events. Finally, an updated picture of the physical properties and the DO distribution is presented based on the last 5 years of measurements and the recent introduction of Bio-Argo floats with DO sensors in the area.

  2. Hydrology and pollution assessment in a coastal estuarine system. The case of the Strymonikos Gulf (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    A. PAVLIDOU

    2012-12-01

    Full Text Available Three hydrographic cruises were undertaken to study the hydrology and to estimate the ecological status of the coastal ecosystem of the Strymonikos Gulf (North Aegean Sea impacted by the riverine waters of the Strymon River. Surface sediments were also collected in order to determine the levels of organic contaminants in the gulf. Three main water masses were identified in the Strymonikos Gulf throughout the year: a the surface river plume water, b the surface and subsurface Black Sea Water and c the near bottom (>50 m water of Levantine origin. High nutrient concentrations were recorded close to the mouth of the river, indicating a rather eutrophic environment, which was restricted near the river discharge. The salinity-nutrient correlations of the surface waters of the study area were linear, indicating that the riverine waters are the major source of nutrient in the gulf. DIN:P ratios varied seasonally from relatively higher values during winter and early spring to lower values in late spring-early summer. This led to a shift from likelihood P-limitation during winter and early spring to N-limitation in late spring – early summer. Total hydrocarbon concentrations measured in the sediments ranged from 19.2 to 95.9 μ g/g, whereas total polycyclic aromatic hydrocarbon (PAH values varied between 107.2 and 1019 ng/g. The application of different diagnostic criteria suggests a natural terrestrial origin for aliphatic hydrocarbons and pyrolytic origin for the PAHs. DDTs displayed the highest concentrations of all the organochlorines determined, whereas polychlorinated biphenyl (PCBs concentrations were very low. Riverine input seems to be the major source for all the compounds identified.

  3. Beneath the Wine-Dark Sea: Marine Imagery and Artefacts from the Bronze Age Aegean

    OpenAIRE

    Saunders, Emma

    2007-01-01

    Exhibited at the second Glucksman Memorial Symposium on June 13th 2007 This project began as an attempt to explain why the Minoan islanders developed and nurtured this marine interest, while neighbouring island cultures did not. In order to understand the enduring popularity of the sea in Minoan art, it is necessary to examine the wider social and religious role of the sea in Bronze Age Crete. As an avid scuba diver, I am also eager to apply marine biological research to identify behaviour...

  4. Source of the tsunami generated by the 1650 AD eruption of Kolumbo submarine volcano (Aegean Sea, Greece)

    Science.gov (United States)

    Ulvrova, Martina; Paris, R.; Nomikou, P.; Kelfoun, K.; Leibrandt, S.; Tappin, D. R.; McCoy, F. W.

    2016-07-01

    The 1650 AD explosive eruption of Kolumbo submarine volcano (Aegean Sea, Greece) generated a destructive tsunami. In this paper we propose a source mechanism of this poorly documented tsunami using both geological investigations and numerical simulations. Sedimentary evidence of the 1650 AD tsunami was found along the coast of Santorini Island at maximum altitudes ranging between 3.5 m a.s.l. (Perissa, southern coast) and 20 m a.s.l. (Monolithos, eastern coast), corresponding to a minimum inundation of 360 and 630 m respectively. Tsunami deposits consist of an irregular 5 to 30 cm thick layer of dark grey sand that overlies pumiceous deposits erupted during the Minoan eruption and are found at depths of 30-50 cm below the surface. Composition of the tsunami sand is similar to the composition of the present-day beach sand but differs from the pumiceous gravelly deposits on which it rests. The spatial distribution of the tsunami deposits was compared to available historical records and to the results of numerical simulations of tsunami inundation. Different source mechanisms were tested: earthquakes, underwater explosions, caldera collapse, and pyroclastic flows. The most probable source of the 1650 AD Kolumbo tsunami is a 250 m high water surface displacement generated by underwater explosion with an energy of ~ 2 × 1016 J at water depths between 20 and 150 m. The tsunamigenic explosion(s) occurred on September 29, 1650 during the transition between submarine and subaerial phases of the eruption. Caldera subsidence is not an efficient tsunami source mechanism as short (and probably unrealistic) collapse durations (< 5 min) are needed. Pyroclastic flows cannot be discarded, but the required flux (106 to 107 m3 · s- 1) is exceptionally high compared to the magnitude of the eruption.

  5. Simulating anchovy's full life cycle in the northern Aegean Sea (eastern Mediterranean): A coupled hydro-biogeochemical-IBM model

    Science.gov (United States)

    Politikos, D.; Somarakis, S.; Tsiaras, K. P.; Giannoulaki, M.; Petihakis, G.; Machias, A.; Triantafyllou, G.

    2015-11-01

    A 3-D full life cycle population model for the North Aegean Sea (NAS) anchovy stock is presented. The model is two-way coupled with a hydrodynamic-biogeochemical model (POM-ERSEM). The anchovy life span is divided into seven life stages/age classes. Embryos and early larvae are passive particles, but subsequent stages exhibit active horizontal movements based on specific rules. A bioenergetics model simulates the growth in both the larval and juvenile/adult stages, while the microzooplankton and mesozooplankton fields of the biogeochemical model provide the food for fish consumption. The super-individual approach is adopted for the representation of the anchovy population. A dynamic egg production module, with an energy allocation algorithm, is embedded in the bioenergetics equation and produces eggs based on a new conceptual model for anchovy vitellogenesis. A model simulation for the period 2003-2006 with realistic initial conditions reproduced well the magnitude of population biomass and daily egg production estimated from acoustic and daily egg production method (DEPM) surveys, carried out in the NAS during June 2003-2006. Model simulated adult and egg habitats were also in good agreement with observed spatial distributions of acoustic biomass and egg abundance in June. Sensitivity simulations were performed to investigate the effect of different formulations adopted for key processes, such as reproduction and movement. The effect of the anchovy population on plankton dynamics was also investigated, by comparing simulations adopting a two-way or a one-way coupling of the fish with the biogeochemical model.

  6. Radiometric dating of sediment cores from a hydrothermal vent zone off Milos Island in the Aegean Sea.

    Science.gov (United States)

    Ugur, Aysun; Miquel, Juan-Carlos; Fowler, Scott W; Appleby, Peter

    2003-05-20

    Sediment cores from a hydrothermal vent zone off Milos Island in the Aegean Sea were dated using the 210Pb method. The average unsupported 210Pb inventory in the cores was calculated to be 3256 Bq m(-2). The corresponding mean annual 210Pb flux of 105 Bq m(-2) year(-1) is comparable to estimates of the atmospheric flux given in the literature. 210Pb fluxes calculated from the unsupported 210Pb inventories in cores are also comparable with the 210Pb vertical fluxes determined from settling particles off the coast of Milos Island. The highest unsupported 210Pb concentrations (89 Bq kg(-1)) were measured in the sediments nearest to the hydrothermal vent area suggesting that the sedimentation rate is lowest at this site. Direct gamma measurements of 210Pb were used to date three sediment cores that are located at different distances from the vent zone: one is in the immediate vicinity of the vent; and others are outside the zone. Sedimentation rates for these cores, calculated using the CRS and CIC models, ranged from 0.088+/-0.008 cm year(-1) to 0.14+/-0.01 cm year(-1). Where both models were applicable, the results given by the two methods were in good agreement. 137Cs concentrations in all three cores generally declined with depth but showed no clear signal of either the period of maximum fallout from weapons testing or the Chernobyl accident. 210Po activities were also measured and the maximum 210Po concentration was in the sediment surface layer (166 Bq kg(-1)).

  7. Ecohydrodynamics of cold-water coral reefs: a case study of the Mingulay Reef Complex (western Scotland.

    Directory of Open Access Journals (Sweden)

    Juan Moreno Navas

    Full Text Available Ecohydrodynamics investigates the hydrodynamic constraints on ecosystems across different temporal and spatial scales. Ecohydrodynamics play a pivotal role in the structure and functioning of marine ecosystems, however the lack of integrated complex flow models for deep-water ecosystems beyond the coastal zone prevents further synthesis in these settings. We present a hydrodynamic model for one of Earth's most biologically diverse deep-water ecosystems, cold-water coral reefs. The Mingulay Reef Complex (western Scotland is an inshore seascape of cold-water coral reefs formed by the scleractinian coral Lophelia pertusa. We applied single-image edge detection and composite front maps using satellite remote sensing, to detect oceanographic fronts and peaks of chlorophyll a values that likely affect food supply to corals and other suspension-feeding fauna. We also present a high resolution 3D ocean model to incorporate salient aspects of the regional and local oceanography. Model validation using in situ current speed, direction and sea elevation data confirmed the model's realistic representation of spatial and temporal aspects of circulation at the reef complex including a tidally driven current regime, eddies, and downwelling phenomena. This novel combination of 3D hydrodynamic modelling and remote sensing in deep-water ecosystems improves our understanding of the temporal and spatial scales of ecological processes occurring in marine systems. The modelled information has been integrated into a 3D GIS, providing a user interface for visualization and interrogation of results that allows wider ecological application of the model and that can provide valuable input for marine biodiversity and conservation applications.

  8. Ecohydrodynamics of cold-water coral reefs: a case study of the Mingulay Reef Complex (western Scotland).

    Science.gov (United States)

    Moreno Navas, Juan; Miller, Peter I; Miller, Peter L; Henry, Lea-Anne; Hennige, Sebastian J; Roberts, J Murray

    2014-01-01

    Ecohydrodynamics investigates the hydrodynamic constraints on ecosystems across different temporal and spatial scales. Ecohydrodynamics play a pivotal role in the structure and functioning of marine ecosystems, however the lack of integrated complex flow models for deep-water ecosystems beyond the coastal zone prevents further synthesis in these settings. We present a hydrodynamic model for one of Earth's most biologically diverse deep-water ecosystems, cold-water coral reefs. The Mingulay Reef Complex (western Scotland) is an inshore seascape of cold-water coral reefs formed by the scleractinian coral Lophelia pertusa. We applied single-image edge detection and composite front maps using satellite remote sensing, to detect oceanographic fronts and peaks of chlorophyll a values that likely affect food supply to corals and other suspension-feeding fauna. We also present a high resolution 3D ocean model to incorporate salient aspects of the regional and local oceanography. Model validation using in situ current speed, direction and sea elevation data confirmed the model's realistic representation of spatial and temporal aspects of circulation at the reef complex including a tidally driven current regime, eddies, and downwelling phenomena. This novel combination of 3D hydrodynamic modelling and remote sensing in deep-water ecosystems improves our understanding of the temporal and spatial scales of ecological processes occurring in marine systems. The modelled information has been integrated into a 3D GIS, providing a user interface for visualization and interrogation of results that allows wider ecological application of the model and that can provide valuable input for marine biodiversity and conservation applications.

  9. Comparison of heavy metal concentration of some marine fishes from Black and Aegean Seas

    Directory of Open Access Journals (Sweden)

    Makedonski Lubomir

    2015-06-01

    Full Text Available Major part of healthy human diet consist of marine fish and seafood products. And it is not surprising that there are numerous studies based on metal accumulation in various fish species. Fish may also be used for heavy metal monitoring programs of marine environments due to their easy sampling, sample preparation and chemical analysis. Concentrations of lead, cadmium, nickel, copper, manganese, zinc, iron, chromium, total mercury and total arsenic were determined in edible part of two commercially valuable fish Greek aquaculture species European sea bass (Dicentrarchus labrax and gilthead sea bream (Sparus aurata purchased from Bulgarian market during 2011. The concentration of metals was measured by atomic absorption spectrophotometry (AAS. The concentration of the heavy metals in examined fish species ranged as follow: Pb 0.008 - 0.013; Cd 0.0017 - 0.022; Ni 0.007 - 0.012; Cu 0.054 - 0.115; Mn 0.043 - 0.09; Zn 0.14 - 0.15; Fe 0.17 - 0.19; Cr 0.05 - 0.07; Hg 0.11 - 0.13; As 1.6 - 1.8 mg kg-1 wet weight, respectively.

  10. The presence of the Indo-Pacific symbiont-bearing foraminifer Amphistegina lobifera in Greek coastal ecosystems (Aegean Sea, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    M.V. TRIANTAPHYLLOU

    2009-12-01

    Full Text Available During the last decades, hundreds of species of Indo-Pacific origin from the Red Sea have traversed the Suez Canal and settled in the Eastern Mediterranean. Nowadays, Amphistegina lobifera Larsen, is known to be a successful immigrant that is widely distributed in the coastal ecosystems of the Eastern Mediterranean Sea. Amphistegina is the most common epiphytic, symbiont- bearing large foraminifer. In this study we provide additional data on the presence of this species in the coastal ecosystems of Aegean Sea, Greece. The high relative abundance of A. lobifera is the result of very successful adaptation of this species to local conditions and suggests that it has become a significant part of the epiphytic foraminiferal fauna.

  11. Investigation of the stochastic nature of wave processes for renewable resources management: a pilot application in a remote island in the Aegean sea

    Science.gov (United States)

    Moschos, Evangelos; Manou, Georgia; Georganta, Xristina; Dimitriadis, Panayiotis; Iliopoulou, Theano; Tyralis, Hristos; Koutsoyiannis, Demetris; Tsoukala, Vicky

    2017-04-01

    The large energy potential of ocean dynamics is not yet being efficiently harvested mostly due to several technological and financial drawbacks. Nevertheless, modern renewable energy systems include wave and tidal energy in cases of nearshore locations. Although the variability of tidal waves can be adequately predictable, wind-generated waves entail a much larger uncertainty due to their dependence to the wind process. Recent research has shown, through estimation of the wave energy potential in coastal areas of the Aegean Sea, that installation of wave energy converters in nearshore locations could be an applicable scenario, assisting the electrical network of Greek islands. In this context, we analyze numerous of observations and we investigate the long-term behaviour of wave height and wave period processes. Additionally, we examine the case of a remote island in the Aegean sea, by estimating the local wave climate through past analysis data and numerical methods, and subsequently applying a parsimonious stochastic model to a theoretical scenario of wave energy production. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  12. Grain size distribution, clay mineralogy and chemistry of bottom sediments from the outer Thermaikos Gulf, Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    K.G. PEHLIVANOGLOU

    2004-06-01

    Full Text Available The Thermaikos Gulf constitutes the NW part of the North Aegean Sea and is limited eastward from the Chalkidiki Peninsula and westward from the Pieria Prefecture. Its plateau covers an area of 3,500 km2. The mechanisms responsible for the grain size distribution into the Gulf, the clay mineralogy and the chemistry of some bottom sediments from the outer Thermaikos Gulf, are examined. Source mixing during transportation, flocculation, differential settling processes and organic matter appear to be the main mechanisms for the distribution of clay minerals in shallow waters. All grain size fractions studied present a wide range of values confirming the extreme variations of the discharged load and the variability in marine processes. Plagioclases predominate over K-feldspars, while quartz is the most abundant mineral present. In addition, micas, chlorites, amphiboles and pyroxenes exist as primary and/or accessory minerals in all samples. Among clay minerals, illite predominates over smectite and smectite over chlorite (+ kaolinite. The ordered interstratified phase of I/S, with 30-35% S layers, is present in the 2-0.25µm fraction. The randomly interstratified phase of I/S, with 50% S layers, is present in the <0.25& micro; m fraction. On average the clay mineral content of the studied samples is: 48% I, 23% S, 17% Ch (+K and 12% others for the 2-0.25µm fraction and 50% I, 30% S and 20% Ch (+K for the <0.25 µm fraction. All these minerals are the weathering products of the rocks from the drainage basins of the rivers flowing into the Gulf, as well as of the Neogene and Quaternary unconsolidated sediments of the surrounding coasts. The terrigenous input, the water mass circulation and, to a lesser extent, the quality of the discharged material and the differential settling of grains, control the grain size distribution within the outer Thermaikos Gulf. The chemical composition of the analysed samples is generally in agreement with their mineral

  13. The East Aegean Sea strong earthquake sequence of October–November 2005: lessons learned for earthquake prediction from foreshocks

    Directory of Open Access Journals (Sweden)

    G. A. Papadopoulos

    2006-01-01

    Full Text Available The seismic sequence of October–November 2005 in the Samos area, East Aegean Sea, was studied with the aim to show how it is possible to establish criteria for (a the rapid recognition of both the ongoing foreshock activity and the mainshock, and (b the rapid discrimination between the foreshock and aftershock phases of activity. It has been shown that before the mainshock of 20 October 2005, foreshock activity is not recognizable in the standard earthquake catalogue. However, a detailed examination of the records in the SMG station, which is the closest to the activated area, revealed that hundreds of small shocks not listed in the standard catalogue were recorded in the time interval from 12 October 2005 up to 21 November 2005. The production of reliable relations between seismic signal duration and duration magnitude for earthquakes included in the standard catalogue, made it possible to use signal durations in SMG records and to determine duration magnitudes for 2054 small shocks not included in the standard catalogue. In this way a new catalogue with magnitude determination for 3027 events was obtained while the standard catalogue contains 1025 events. At least 55 of them occurred from 12 October 2005 up to the occurrence of the two strong foreshocks of 17 October 2005. This implies that foreshock activity developed a few days before the strong shocks of 17 October 2005 but it escaped recognition by the routine procedure of seismic analysis. The onset of the foreshock phase of activity is recognizable by the significant increase of the mean seismicity rate which increased exponentially with time. According to the least-squares approach the b-value of the magnitude-frequency relation dropped significantly during the foreshock activity with respect to the b-value prevailing in the declustered background seismicity. However, the maximum likelihood approach does not indicate such a drop of b. The b-value found for the aftershocks that

  14. On the interrelation of fluid-induced seismicity and crustal deformation at Columbo Seamount (Aegean Sea, Greece)

    Science.gov (United States)

    Hensch, M.; Dahm, T.; Hort, M.; Huebscher, C.; Dehghani, A.

    2009-04-01

    The Columbo submarine volcano is part of the Santorini volcanic complex, located in the center of the Hellenic volcanic arc, Aegean Sea, approximately 8km north-east of Santorini island. The Columbo seamount has attracted attention since island based monitoring indicated high seismicity rate and crustal deformation which both might be related to fluid migration in the subsurface. In addition to the island-based seismic network, 4 Ocean-Bottom-Seismometers (OBS) and 4 newly developed -Tiltmeters (OBT) have been deployed on top and in the vicinity of the seamount during the Columbo experiment between June 2006 and March 2007. Aim of the local experiment was to reduce the azimuthal gap between the islands, to get precise depth locations of the events and measuring tilt signals directly in the epicentral region. OBTs were additionally equipped with hydrophones to measure seismic signals and absolute pressure gauges to observe possible uplift or subsidence. A STA/LTA trigger applied to the seismic data delivered over 14.000 triggers for local and regional events over the whole deployment. At least 8 earthquake swarms with event rates of up to 230 events per day occurred during the experiment. First relocation results estimate a depth range between 5 and 15km for the seismic swarms. Centroids of these earthquake clusters are distributed beneath and in the vicinity of the Columbo caldera and SW of Columbo, in direction of Santorini volcano. Parallel to these sequences of seismic unrest, we observe long-period tilt signals occurring over several days or weeks, which might reflect slow, but permanent deformation at the seamount. Purpose of the study is to find evidences for swarm triggers, such as fluid migration, by precisely relocating the events by means of multiple event methods in order to investigate the migration behavior of the seismic clusters and by studying focal mechanisms of the events. In a second step, we compare observed tilt signals with the behavior of the

  15. Grain size distribution, clay mineralogy and chemistry of bottom sediments from the outer Thermaikos Gulf, Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    K.G. PEHLIVANOGLOU

    2012-12-01

    Full Text Available The Thermaikos Gulf constitutes the NW part of the North Aegean Sea and is limited eastward from the Chalkidiki Peninsula and westward from the Pieria Prefecture. Its plateau covers an area of 3,500 km2. The mechanisms responsible for the grain size distribution into the Gulf, the clay mineralogy and the chemistry of some bottom sediments from the outer Thermaikos Gulf, are examined. Source mixing during transportation, flocculation, differential settling processes and organic matter appear to be the main mechanisms for the distribution of clay minerals in shallow waters. All grain size fractions studied present a wide range of values confirming the extreme variations of the discharged load and the variability in marine processes. Plagioclases predominate over K-feldspars, while quartz is the most abundant mineral present. In addition, micas, chlorites, amphiboles and pyroxenes exist as primary and/or accessory minerals in all samples. Among clay minerals, illite predominates over smectite and smectite over chlorite (+ kaolinite. The ordered interstratified phase of I/S, with 30-35% S layers, is present in the 2-0.25µm fraction. The randomly interstratified phase of I/S, with 50% S layers, is present in the <0.25& micro; m fraction. On average the clay mineral content of the studied samples is: 48% I, 23% S, 17% Ch (+K and 12% others for the 2-0.25µm fraction and 50% I, 30% S and 20% Ch (+K for the <0.25 µm fraction. All these minerals are the weathering products of the rocks from the drainage basins of the rivers flowing into the Gulf, as well as of the Neogene and Quaternary unconsolidated sediments of the surrounding coasts. The terrigenous input, the water mass circulation and, to a lesser extent, the quality of the discharged material and the differential settling of grains, control the grain size distribution within the outer Thermaikos Gulf. The chemical composition of the analysed samples is generally in agreement with their mineral

  16. Assessment of heavy metal contamination in core sediment samples in Gulf of Izmir, Aegean Sea, Turkey (by inductively coupled plasma-optical emission spectrometry (ICP-OES))

    Science.gov (United States)

    Ünal Yumun, Zeki; Kam, Erol; Kurt, Dilek

    2017-04-01

    Heavy metal and radionuclide analysis studies are crucial in explaining biotic and abiotic interactions in ecosystems. This type of analysis is highly needed in environments such as coastal areas, gulfs or lakes where human activities are generally concentrated. Sediments are one of the best biological indicators for the environment since the pollution accumulates in the sediments by descent to the sea floor. In this study, sediments were collected from the Gulf of Izmir (Eastern Aegean Sea, Turkey) considering the accumulated points of domestic and industrial wastes to make an anthropogenic pollution analysis. The core sediments had different depths of 0.00-30.00 m at four different locations where Karsiyaka, Bayrakli, Incialti and Cesmealti in the Gulf of Izmir. The purpose of the study was determining Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in the drilling samples to assess their levels and spatial distribution in crucial areas of the Aegean Sea by inductively coupled plasma-optical emission spectrometry (ICP-OES) with microwave digestion techniques. The heavy metal concentrations found in sediments varied for Cd:

  17. Petrological insights on the effusive-explosive transitions of the Nisyros-Yali Volcanic Center, South Aegean Sea

    Science.gov (United States)

    Popa, Razvan-Gabriel; Bachmann, Olivier; Ellis, Ben; Degruyter, Wim; Kyriakopoulos, Konstantinos

    2017-04-01

    Volcanoes erupting silicic, volatile-rich magmas can exhibit both effusive and explosive eruptions, even during closely spaced eruptive episodes. Understanding the effusive-explosive transition is fundamental in order to assess the hazards involved. Magma properties strongly influence the processes during magma ascent that determine the eruptive style. Here, we investigate the link between changing conditions in the magma reservoir and the eruptive style. The Quaternary Nisyros-Yali volcanic center, from the South Aegean Sea, provides an excellent natural laboratory to study this process. Over the last 60-100 kyrs, it produced a series of dacitic to rhyolitic eruptions that emplaced alternating effusive and explosive deposits (with explosive eruptions likely shortly following effusive ones). For this study, nine fresh and well-preserved units (five effusive and four explosive) were sampled and analyzed for whole-rock, groundmass glass and mineral compositions, in order to draw insights into the magma chamber processes and thermodynamic conditions that preceded both types of eruptions. Silicic magmas in Nisyros-Yali record a complex, open-system evolution, dominated by fractionation in mushy reservoirs at mid to upper crustal depths, frequently recharged by warmer input from below. Storage temperatures recorded by the amphibole-plagioclase thermometer span a wide range, and they are always cooler than the pre-eruptive temperatures yielded by Fe-Ti oxide thermometry for the same unit, whether it is effusive or explosive. However, magmas feeding effusive eruptions typically reached cooler conditions (expressed by the presence of low-Al, low-Ti amphiboles) than in the explosive cases. The difference between the pre-eruptive and the lowest storing temperatures in the Nisyros series are in the order of 10-30°C for explosive units, while the difference is of about 40-110°C for the effusive units. The Yali series does not perfectly fit this pattern, where explosive units

  18. Seismicity and active tectonics at Coloumbo Reef (Aegean Sea, Greece): Monitoring an active volcano at Santorini Volcanic Center using a temporary seismic network

    Science.gov (United States)

    Dimitriadis, I.; Karagianni, E.; Panagiotopoulos, D.; Papazachos, C.; Hatzidimitriou, P.; Bohnhoff, M.; Rische, M.; Meier, T.

    2009-02-01

    The volcanic center of Santorini Island is the most active volcano of the southern Aegean volcanic arc. Α dense seismic array consisting of fourteen portable broadband seismological stations has been deployed in order to monitor and study the seismo-volcanic activity at the broader area of the Santorini volcanic center between March 2003 and September 2003. Additional recordings from a neighbouring larger scale temporary network (CYCNET) were also used for the relocation of more than 240 earthquakes recorded by both arrays. A double-difference relocation technique was used, in order to obtain optimal focal parameters for the best-constrained earthquakes. The results indicate that the seismic activity of the Santorini volcanic center is strongly associated with the tectonic regime of the broader Southern Aegean Sea area as well as with the volcanic processes. The main cluster of the epicenters is located at the Coloumbo Reef, a submarine volcano of the volcanic system of Santorini Islands. A smaller cluster of events is located near the Anydros Islet, aligned in a NE-SW direction, running almost along the main tectonic feature of the area under study, the Santorini-Amorgos Fault Zone. In contrast, the main Santorini Island caldera is characterized by the almost complete absence of seismicity. This contrast is in very good agreement with recent volcanological and marine studies, with the Coloumbo volcanic center showing an intense high-temperature hydrothermal activity, in comparison to the corresponding low-level activity of the Santorini caldera. The high-resolution hypocentral relocations present a clear view of the volcanic submarine structure at the Coloumbo Reef, showing that the main seismic activity is located within a very narrow vertical column, mainly at depths between 6 and 9 km. The focal mechanisms of the best-located events show that the cluster at the Coloumbo Reef is associated with the "Kameni-Coloumbo Fracture Zone", which corresponds to the

  19. Investigation of heavy metal pollution in eastern Aegean Sea coastal waters by using Cystoseira barbata, Patella caerulea, and Liza aurata as biological indicators.

    Science.gov (United States)

    Aydın-Önen, S; Öztürk, M

    2017-01-19

    In order to have an extensive contamination profile of heavy metal levels (Cd, Cu, Fe, Mn, Ni, Pb, and Zn), seawater, sediment, Patella caerulea, Cystoseira barbata, and Liza aurata were investigated by using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples were collected from five coastal stations along the eastern Aegean Sea coast (Turkey) on a monthly basis from July 2002 through May 2003. According to the results of this study, heavy metal levels were arranged in the following sequence: Fe > Pb > Zn > Mn > Ni > Cu > Cd for water, Fe > Cu > Mn > Ni > Zn > Pb > Cd for sediment, Fe > Zn > Mn > Pb > Ni > Cd > Cu for C. barbata, Fe > Zn > Mn > Ni > Pb > Cu > Cd for P. caerulea, and Fe > Zn > Mn > Cu > Ni > Pb > Cd for L. aurata. Moreover, positive relationships between Fe in water and Mn in water, Fe in sediment and Mn in sediment, Fe in C. barbata and Mn in C. barbata, Fe in P. caerulea and Mn in P. caerulea, and Fe in L. aurata and Mn in L. aurata may suggest that these metals could be originated from the same anthropogenic source. C. barbata represented with higher bioconcentration factor (BCF) values, especially for Fe, Mn, and Zn values. This observation may support that C. barbata can be used as an indicator species for the determinations of Fe, Mn, and Zn levels. Regarding Turkish Food Codex Regulation's residue limits, metal values in L. aurata were found to be lower than the maximum permissible levels issued by Turkish legislation and also the recommended limits set by FAO/WHO guidelines. The results of the investigation indicated that P. caerulea, L. aurata, and especially C. barbata are quantitative water-quality bioindicators and biomonitoring subjects for biologically available metal accumulation for Aegean Sea coastal waters.

  20. An integrated zircon geochronological and geochemical investigation into the Miocene plutonic evolution of the Cyclades, Aegean Sea, Greece: Part 1: Geochronology

    Science.gov (United States)

    Bolhar, Robert; Ring, Uwe; Allen, Charlotte M.

    2010-11-01

    We use 369 individual U-Pb zircon ages from 14 granitoid samples collected on five islands in the Cyclades in the Aegean Sea, Greece, for constraining the crystallisation history of I- and S-type plutons above the retreating Hellenic subduction zone. Miocene magmatism in the Cyclades extended over a time span from 17 to 11 Ma. The ages for S-type granites are systematically ~2 million years older than those for I-type granites. Considering plutons individually, the zircon data define age spectra ranging from simple and unimodal to complex and multimodal. Seven of the 14 investigated samples yield more than one distinct zircon crystallisation age, with one I-type granodiorite sample from Mykonos Island representing the most complex case with three resolvable age peaks. Two samples from S-type granites on Ikaria appear to have crystallised zircon over 2-3 million years, whereas for the majority of individual samples with multiple zircon age populations the calculated ages deviate by 1-1.5 million years. We interpret our age data to reflect a protracted history involving initial partial melting at deeper lithospheric levels, followed by crystallisation and cooling at shallower crustal levels. Our study corroborates published research arguing that pluton construction is due to incremental emplacement of multiple magma pulses over a few million years. Assuming that multiple age peaks of our 14 samples can indeed serve to quantify time spans for magmatic emplacement, our data suggest that Aegean plutons were constructed over a few million years. Our tectonic interpretation of the U-Pb ages is that the S-type granites resulted from partial melting and migmatisation of the lower crust, possibly starting at ~23 Ma. The I-type granites and associated mafic melts are interpreted to reflect the magmatic arc stage in the Cyclades starting at ~15 Ma.

  1. A new artificial reef design for octopus (Octopus vulgaris cuvier, 1797 in the Aegean sea and preliminary results

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    Ali Ula

    2011-01-01

    Full Text Available This study was carried out in the Gulf of 0zmir in the Aegean Sea between June 2006 and November 2008. The purpose was the creation of a new concept of the artificial reef for Octopus vulgaris, with a view to establishing new artificial reef sites to be used in the fisheries management of this species (MPA, NTZ or fishing areas. First, the main characteristics of natural octopus nests were recorded (entrance width, length, etc. by divers. These characteristics were used in the construction of new octahedral artificial reef blocks. The blocks were made of reinforced concrete, in a shape like that of an inverted pyramid, with an upper surface of 100x100x25 cm³ and a lower one of 60x60 cm². Four cylindrical holes each with two ellipsoidal openings were placed in one face and in the lateral edge of the octo-block, to serve as the entrances to the artificial nest. Each nest has a volume of 5000 cm³. Eighty octo-blocks were deployed as artificial reefs at 10 m from each other at 15 different depths at two sites by divers with the help of the winch of the R/V EGESUF. These artificial octo-reefs were censused by direct observation. Twenty-eight octopuses were sampled at the end of 25 dives. Minimum mantle length of the octopuses was 75 mm and the maximum 249 mm, with an average of 152.71 mm. The average total length was calculated to be 918.57 mm. The weight of the specimens was between 244 g and 7140 g with an average of 2335.43 g. The results showed that both sites were inhabited by octopuses coming from the artificial reefs, which used them as nests. These nests seem to have constituted special places for fisheries management and will permit the assessment of reserve areas or marine protection areas (MPA, thus opening up a new perspective for Turkish fisheries.Este estudo foi realizado no golfo de 0zmir, no Mar Egeu, entre junho de 2006 e novembro de 2008. O objetivo foi uma nova concepção de recife artificial para Octopus vulgaris, visando o

  2. Implementation of a reduced order Kalman filter to assimilate ocean color data into a coupled physical-biochemical model of the North Aegean Sea.

    Science.gov (United States)

    Kalaroni, Sofia; Tsiaras, Kostas; Economou-Amilli, Athena; Petihakis, George; Politikos, Dimitrios; Triantafyllou, George

    2013-04-01

    Within the framework of the European project OPEC (Operational Ecology), a data assimilation system was implemented to describe chlorophyll-a concentrations of the North Aegean, as well the impact on the European anchovy (Engraulis encrasicolus) biomass distribution provided by a bioenergetics model, related to the density of three low trophic level functional groups of zooplankton (heterotrophic flagellates, microzooplankton and mesozooplankton). The three-dimensional hydrodynamic-biogeochemical model comprises two on-line coupled sub-models: the Princeton Ocean Model (POM) and the European Regional Seas Ecosystem Model (ERSEM). The assimilation scheme is based on the Singular Evolutive Extended Kalman (SEEK) filter and its variant that uses a fixed correction base (SFEK). For the initialization, SEEK filter uses a reduced order error covariance matrix provided by the dominant Empirical Orthogonal Functions (EOF) of model. The assimilation experiments were performed for year 2003 using SeaWiFS chlorophyll-a data during which the physical model uses the atmospheric forcing obtained from the regional climate model HIRHAM5. The assimilation system is validated by assessing the relevance of the system in fitting the data, the impact of the assimilation on non-observed biochemical parameters and the overall quality of the forecasts.

  3. Temporal variability of the microbial food web (viruses to ciliates under the influence of the Black Sea Water inflow (N. Aegean, E. Mediterranean

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    A. GIANNAKOUROU

    2015-01-01

    Full Text Available Τhe entire pelagic microbial food web was studied during the winter-spring period in the frontal area of the North Aegean Sea. Abundance of viruses, heterotrophic bacteria, cyanobacteria, auto- and hetero-trophic flagellates, and ciliates, as well as bacterial production, were measured at three stations (MD1, MD2, MD3 situated along a N-S transect between the area directly influenced by the inflowing Black Sea water and the area covered by the Levantine water. Samples were collected in December 2009, and January, March, April, and May 2011. Station MD1 exhibited the highest values of abundance and integrated biomass of all microbial groups and bacterial production during all months, and MD3 the lowest. Bacteria dominated the total integrated biomass at all stations and months, followed by cyanobacteria, auto-, hetero-trophic flagellates and ciliates. On a temporal scale, the microbial food web was less important in March as all microbial parameters at all stations showed the lowest values. After the phytoplankton bloom in March, the heterotrophic part of the microbial food web (mainly strongly increased, though the intensity of the phenomenon was diminished from North to South. Pico-sized plankton was found to be heterotrophic whereas nanoplankton was autotrophic. It seems that the influence of the Black Sea water on station MD1, permanent throughout the study period of early winter to late spring, was reflected in all microbial populations studied, and produced a more productive pelagic food web system, with potential consequences for the upper trophic levels.

  4. Modelling the water mass exchange through navigational channels connecting adjacent coastal basins - application to the Channel of Potidea (North Aegean Sea

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    Y. G. Savvidis

    2005-02-01

    Full Text Available The research objective is the detection of the mechanism of the water mass exchange through a navigational channel connecting two adjacent coastal basins. The research involves the application of a mathematical model in parallel to in-situ measurements. The hydrodynamic circulation in the greater area of the NW Aegean Sea is modeled by means of a barotropic circulation model. Wind, Coriolis and Tide are the main forcings taken into account. The flow through the channel is resolved at a subgrid scale by means of a local open channel flow model. The comparison between field measurements, recorded during a limited period, and the model results supports the model verification. The study is integrated by an operational application of the model under various realistic forcings. The results help to gain a better understanding of the mechanisms regulating the water mass exchange and the consequent interaction between two adjacent connected coastal basins. From the case study of the Potidea channel it is revealed that the water mass exchange under mean wind forcing is of the same order as the one induced by the tidal forcing.

  5. Marine pollution risk in a coastal city: use of an eco-genotoxic tool as a stress indicator in mussels from the Eastern Aegean Sea.

    Science.gov (United States)

    Kacar, Asli; Pazi, Idil; Gonul, Tolga; Kucuksezgin, Filiz

    2016-08-01

    Coastal areas, such as bays, estuaries, and harbors, are heavily polluted since these areas are the settlements to which toxic chemicals from industrial and domestic wastes are discharged. The genetic damage was evaluated using bioindicator mussel Mytilus galloprovincialis caused by toxic chemicals (metals and polycyclic aromatic hydrocarbons) in İzmir and Çandarlı Bays (the Eastern Aegean Sea) through comet assay. Three sampling sites from the two bays were selected and the study was conducted during the spring and autumn periods. The highest levels of DNA damage expressed as %Tail-DNA were observed in İzmir Bay (34.60 % Tail-DNA) in the spring. Analysis of the correlation between PAHs and metals in mussels and %T-DNA in the hemolymph and gill cells showed a statistically significant positive correlation between %T-DNA and ∑PAH, chromium (p llution level of the İzmir and Çandarlı Bays by using the DNA damage to the mussel, which can identify the effects of environmental pollutants at the cellular levels. These results confirm that comet assay can be used to determine the temporal and spatial differences of DNA damage, and as a suitable tool for the measurement of genotoxicity in regions with low pollutant concentrations.

  6. Hydrodynamic features of the South Aegean Sea as derived from Argo T/S and dissolved oxygen profiles in the area

    Science.gov (United States)

    Kassis, Dimitris; Krasakopoulou, Evangelia; Korres, Gerasimos; Petihakis, George; Triantafyllou, George S.

    2016-09-01

    In this work, the hydrodynamic picture of the South Aegean Sea is examined through an analysis of recent measurements in its sub-basins, the Myrtoan and Cretan Sea. Both sub-basins play an important role in the water circulation, exchange, and formation processes that affect the dynamics of the whole Eastern Mediterranean. For the first time, Bio-Argo floats were deployed in the area under the Greek Argo Research Infrastructure coordination. The acquired profiles cover an almost 2-year period (November 2013-July 2015) and are compared with previous Argo profiles and the re-processed time-series data recorded from the E1-M3A POSEIDON observatory operating in the area since 2007. The spatio-temporal distribution of the physical and chemical properties in each sub-basin is examined. Dense water formation events are revealed in the northern part (Myrtoan), while the wider area can be characterized as pre-conditioned. In the Cretan basin, a strong inter-annual variability of the salinity field at intermediate and deep layers is observed that is associated with water exchange from its open boundaries. Furthermore, comparison of the dissolved oxygen (DO) distribution with physical water properties within both the mixed layer, and at greater depths, indicated that relatively high but still under-saturated DO values are more likely to be associated with convection events. Finally, an updated picture of the physical properties and the DO distribution is presented based on the last 5 years of measurements and the recent introduction of Bio-Argo floats with DO sensors in the area.

  7. Setting an ecological baseline prior to the bottom-up establishment of a marine protected area in Santorini island, Aegean Sea

    Directory of Open Access Journals (Sweden)

    M. SALOMIDI

    2016-08-01

    Full Text Available Since 2010, a bottom-up initiative has been launched in Santorini Island (Aegean Sea, Eastern Mediterranean for the establishment of the first fully-protected marine protected area in the Cyclades, aiming at improving fisheries and enhancing responsible recreational uses at sea. Following discussions with local small-scale fishers and divers, two sites along the southern and southeastern coasts of the island were suggested as suitable to this end. In 2012, a baseline study was conducted at these areas to assess their state and provide an ecological snapshot that would enable sound designation and monitoring. Several ad hoc indices and metrics were applied, taking into account structural and functional features of the upper infralittoral algae and Posidonia oceanica beds. An integrated assessment of the infralittoral fish assemblages and their associated benthic communities was also performed. Our most important findings were: (i the low total fish biomass and the absence of adult top predators, indicating overfishing; (ii the overgrazing effects of the overabundant alien herbivore spinefoot fishes (Siganus spp., as reflected by the abnormal structure of the algal communities; (iii the scarcity of signs of pollution or other direct anthropogenic pressures, as indicated by the good environmental status of the P. oceanica meadows and the upper infralittoral vegetation; and (iv the presence of a rich diversity of species and habitats, especially along the Akrotiri Peninsula and the wider volcanic Caldera. These findings provide useful insights on strengths and weaknesses of the study area and are discussed together with their implications for protection and management.

  8. Tectono-stratigraphic evolution through successive extensional events of the Anydros Basin, hosting Kolumbo volcanic field at the Aegean Sea, Greece

    Science.gov (United States)

    Nomikou, P.; Hübscher, C.; Ruhnau, M.; Bejelou, K.

    2016-03-01

    The structural evolution of the South Aegean Sea is little explored due to the lack of marine seismic data. Our present day understanding is mainly based on some island outcrops and GPS measurements. In this study we discuss the rather incremental opening of the Anydros Basin in the Pliocene during six major tectonic pulses and the subsequent basin fill processes by interpreting seismic data and derived time isochore maps. Between the active pulses basin floor tilting persisted on a much lower rate. Seismic data illustrate the depositional processes in the emerging Anydros Basin. The observation of onlap fill strata, divergent reflection pattern, moat channels and contourite drifts imply that deposition was controlled by turbidity and contour currents as well as the tilting basin floor. The metamorphic Attico-Cycladic basement shows a rise that aligns along an NW-SE directed axis crossing Anydros island. This axis marks a structural change of the Santorini-Amorgos Ridge and thus represents a major structural boundary. Dip angles of NE-SW trending major faults, like the Santorini-Amorgos Fault, indicate normal faulting to be the superior mechanism forming the present horst and graben environment. Hence, the area is likely to be in a state of NW-SE directed extensional stresses forming the asymmetric graben structure of Anydros. Secondary fault clusters strike the same direction but show much steeper dip angles, possibly indicating strike-slip movement or resulting from deformational stresses along the hinge zones of the normal faults. The majority of the faults we discovered are located in the area of earthquake clusters, which is another indication of recent faulting. Ring faults around Kolumbo submarine volcano, result from caldera collapse and mark the diameter of the magma chamber approximately to 20 km.

  9. Monitoring heavy metal pollution in foraminifera from the Gulf of Edremit (northeastern Aegean Sea) between Izmir, Balıkesir and Çanakkale (Turkey)

    Science.gov (United States)

    Yümün, Zeki Ünal; Önce, Melike

    2017-06-01

    In this study, the populations and abnormal shell structures of Quaternary foraminifers in the sediments of the North-eastern Aegean Sea were examined. For this purpose, offshore drilling was carried out at three locations, and core samples were collected from 13 locations at Küçükkuyu (Çanakkale), Güre (Edremit-Balıkesir) and Dikili (İzmir). At these points, drilling reached depths ranging from 3.00 to 22.00 m beneath the seafloor; recent sediments were observed, but the bedrock was not reached. Examination of the faunal and sedimentological properties of the samples showed that the Gulf of Edremit is completely influenced by the sea and has rich foraminifers and ostracod populations. The abnormalities observed in the foraminifer shells, as well as the yellow- and/or black-coloured shells seen in both the foraminifer and ostracod populations, are due to natural and anthropogenic ecological pollution. The vertical (chronological) and horizontal (spatial) distributions of heavy metal concentrations in both the core and drill core samples were investigated to determine the causes of the morphological abnormalities observed in the foraminifers. In the present study, pollution index (PI) values were calculated to assess the degree of heavy metal pollution (Yümün 2017). The current land use status of the coastal areas corresponding to the measured PI values was investigated to identify the sources of the pollution. Especially in the Güre region, a large number of genera and species of benthic foraminifers showed overgrowth in the shell sizes of individuals, and the coloration of the shells is noteworthy. These changes in the shells are a result of thermal sources and agricultural activities in the region. Scanning electron microscopy (SEM) was used to perform an elemental analysis of the surfaces of dark yellow-orange foraminifers (Ammonia compacta and Elphidium crispum). The S, Fe and Mn concentrations in the shells were found to be high, based on the SEM

  10. Geomorphological characteristics of the onshore/offshore volcanic edifices with respect to their evolutionary stage in the South Aegean Sea, Greece.

    Science.gov (United States)

    Carey, S.; Nomikou, P.; Papanikolaou, D.; Alexandri, M.

    2014-12-01

    Volcanism in the South Aegean Sea first occurred about 3-4 million years ago, along four different volcanic island groups, including both onshore and recently discovered offshore volcanoes: 1) Starting from the west, the Methana group consists of the Methana stratovolcano, composed exclusively of volcaniclastics and lavas, creating cones and domes onland and the Paphsanias submarine cone in the Epidavros tectonic graben, bordered by E-W normal faults. It has a 2 km basal diameter at 400 m depth and its top rises to 150 m. 2) The Milos-Antimilos group consists of volcanic domes and calderas onland and three submarine domes to the east of Antimilos. A hydrothermal vent field is limited in the SE coastal zone of Milos, 3) The Santorini group consists of: (i) the older volcanic cones of Christianna islets and three submarine domes east of them, (ii) Santorini volcano which during the last 500 ka experienced repeated caldera collapses following Plinian eruptions and edifice rebuilding, represented by the growth of the Kamenes islands after the last catastrophic Late Bronze age eruption. (iii) a chain of about twenty submarine volcanic domes and craters in the Kolumbo zone northeast of Santorini. Kolumbo volcano is a 3 km diameter cone with a 1500 m wide crater, a crater rim as shallow as 18 m depth and a flat crater floor at 505 m depth containing an active hydrothermal vent field degassing 99% of CO2. 4) The Kos-Nisyros group at the eastern edge of the Hellenic Volcanic arc, comprises several domes and craters offshore and Nisyros volcano consists exclusively of alternating lava and pyroclastic deposits following several phases of reconstruction and caldera collapse. The rhyodacitic domes of Profitis Ilias are the latest evolutionary stage of Nisyros volcano which disrupted a pre-existed caldera and may be regarded as an earlier reconstruction phase similar to the Kameni islands at Santorini. The volcanic relief reaches 1100-1200 m in most cases. This is produced from

  11. Evaluation of sediment contamination by monoaromatic hydrocarbons in the coastal lagoons of Gulf of Saros, NE Aegean Sea.

    Science.gov (United States)

    Ünlü, Selma; Alpar, Bedri

    2017-05-15

    The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC-MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg(-1) dw, with a mean value of 61.5μgkg(-1) dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons. Copyright © 2017. Published by Elsevier Ltd.

  12. New boron isotopic evidence for sedimentary and magmatic fluid influence in the shallow hydrothermal vent system of Milos Island (Aegean Sea, Greece)

    Science.gov (United States)

    Wu, Shein-Fu; You, Chen-Feng; Lin, Yen-Po; Valsami-Jones, Eugenia; Baltatzis, Emmanuel

    2016-01-01

    Magmatic sources may contribute a significant amount of volatiles in geothermal springs; however, their role is poorly understood in submarine hydrothermal systems worldwide. In this study, new results of B and δ11B in 41 hydrothermal vent waters collected from the shallow hydrothermal system of Milos island in the Aegean Sea were combined with previously published data from other tectonic settings and laboratory experiments to quantify the effects of phase separation, fluid/sediment interaction and magmatic contribution. Two Cl-extreme solutions were identified, high-Cl waters (Cl as high as 2000 mM) and low-Cl waters (Cl < 80 mM). Both sets of waters were characterized by high B/Cl (~ 1.2-5.3 × 10- 3 mol/mol) and extremely low δ11B (1.4-6.3‰), except for the waters with Mg content of near the seawater value and δ11B = 10.3-17.4‰. These high-Cl waters with high B/Cl and low δ11B plot close to the vent waters in sediment-hosted hydrothermal system (i.e., Okinawa Trough) or fumarole condensates from on-land volcanoes, implying B addition from sediment or magmatic fluids plays an important role. This is in agreement with fluid/sediment interactions resulting in the observed B and δ11B, as well as previously reported Br/I/Cl ratios, supporting a scenario of slab-derived fluid addition with elevated B, 11B-rich, and low Br/Cl and I/Cl, which is derived from the dehydration of subducted-sediments. The slab fluid becomes subsequently mixed with the parent magma of Milos. The deep brine reservoir is partially affected by injections of magmatic fluid/gases during degassing. The results presented here are crucial for deciphering the evolution of the brine reservoirs involved in phase separation, fluid/sediment interaction and magmatic contribution in the deep reaction zone of the Milos hydrothermal system; they also have implications in the understanding of the formation of metallic vein mineralization.

  13. Gis-based assessment of marine oil spill hazard and environmental vulnerability for the coasts of Crete in South Aegean Sea

    Science.gov (United States)

    Spanoudaki, Katerina; Nikiforakis, Ioannis K.; Kampanis, Nikolaos A.

    2017-04-01

    Developing effective early warning and coordination systems can save thousands of lives and protect people, property and the environment in the event of natural and man-made disasters. In its document "Towards Better Protection of Citizens against Disaster Risks: Strengthening Early Warning Systems in Europe", the Commission points out that it seeks to follow a multi-hazard approach, to develop near real time alert systems, to ensure a near real time dissemination of alerts to Participating States, and to improve its rapid analytical capacity. In this context, the EU project DECATASTROPHIZE (http://decatastrophize.eu/project/) co-financed by the EU Humanitarian Aid and Civil Protection aims to develop a Geospatial Early warning Decision Support System (GE-DSS) to assess, prepare for and respond to multiple and/or simultaneous natural and man-made hazards, disasters, and environmental incidents by using existing models/systems in each partner country (Cyprus, France, Greece, Italy and Spain) in a synergistic way on ONE multi-platform, called DECAT. Specifically, project partners will establish appropriate geo-databases for test areas and use existing hazard models to produce hazard and vulnerability geo-spatial information for earthquakes, landslides, tsunamis, floods, forest fires and marine oil spills. The GE-DSS in will consist of one source code with six geodatabases, i.e., one for each partner and risk data in the respective test area. Each partner organization will be able to manage and monitor its own data/database and their results using Multi-Criteria Decision Analysis (MCDA). The GE-DSS will be demonstrated at the local, regional and national levels through a set of Command Post and Table Top Disaster Exercises. As part of the DECAT GE-DSS, the gis-based geo-database and assessment of marine oil spill hazard and environmental vulnerability for the coasts of Crete in South Aegean Sea are presented here. Environmental Sensitivity Index (ESI) maps are

  14. Hydrology and circulation in the North Aegean (eastern Mediterranean throughout 1997 and 1998

    Directory of Open Access Journals (Sweden)

    V. ZERVAKIS

    2012-12-01

    Full Text Available The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water, and is still traceable in the water column in late summer.

  15. Modeling the nitrogen cycling and plankton productivity in the Black Sea using a three-dimensional interdisciplinary model

    NARCIS (Netherlands)

    Grégoire, M.; Soetaert, K.E.R.; Nezlin, N.; Kostianoy, A.

    2004-01-01

    A six-compartment ecosystem model defined by a simple nitrogen cycle is coupled with a general circulation model in the Black Sea so as to examine the seasonal variability of the ecohydrodynamics. Model results show that the annual cycle of the biological productivity of the whole basin is character

  16. Geochemistry of mylonitic gneisses from the Cycladic Basement Unit (Paros and Serifos, Aegean Sea): implications for protoliths of the high-grade gneisses

    Science.gov (United States)

    McGrath, Annette; Stouraiti, Christina; Windley, Brian

    2016-10-01

    The nature of the protolith(s) of high-grade gneisses from the Aegean Cycladic Basement Unit of the islands of Paros and Serifos is investigated using whole-rock geochemistry and Sr-Nd-O isotopes, in order to better understand their origin and to compare with possible equivalents from the southern Aegean region. On Paros, the basement unit consists of heterogeneous, mylonitized upper amphibolite-grade paragneisses and associated migmatitic rocks, whereas on Serifos, it consists of a mylonitized felsic gneiss, intercalated with layers and lenses of S-type leucogranites and minor mafic metavolcanics. New Nd, Sr and O isotope data suggest a predominantly crustal-derived source in the gneiss protolith from both islands: high initial 87Sr/86Sr ratios (≥7052 to 0.711, calculated at 300 Ma), negative initial ɛNd (-2.8 to -7.7) values for bulk-rock gneiss samples, and high δ18O values of quartz separates (+10 to +12.7 ‰). Major and trace-element variations corroborate that chemical differentiation within the NW Paros gneiss subunit results from progressive migmatitization. Peraluminous gneisses from eastern Paros share clear similarities with metapelitic gneisses from the Naxos gneiss dome, in terms of their trace-element patterns, ɛNd (300) and O isotope characteristics. The mineral assemblage, the fine grain size (due to intense mylonitization), and the metaluminous affinity of the South Serifos grey quartzofeldpathic gneiss do not allow for an unambiguous interpretation for these undated rocks; however, a combination of geochemical parameters and tectonic discrimination diagrams indicates an immature siliciclastic (greywacke) protolith from a continental island arc setting. Sr-Nd isotopic systematics indicates an increasing lower crustal component in gneisses from NW Paros, which is closer to the migmatitic core of the Paros dome. The overall isotopic trend of the gneissic Cycladic Basement Unit on Paros is spatially correlated with that of the Naxos gneiss dome.

  17. Wild fire effects on floristic diversity in three thermo-Mediterranean vegetation types in a small islet of eastern Aegean sea

    Science.gov (United States)

    Abraham, Eleni; Kyriazopoulos, Apostolos; Korakis, George; Parissi, Zoi; Chouvardas, Dimitrios

    2014-05-01

    Sclerophyllus scrub formations, the main vegetation type in many islands of the Aegean area, are characterized by their high biodiversity. Dominant shrub species of sclerophyllus formations are well adapted to dry season conditions by various anatomical and physiological mechanisms. As a result, their biomass acts as very flammable fine fuel, and consequently wild fires are very common in these ecosystems. Wildfire effects on vegetation and biodiversity in the Mediterranean basin have been studied and the results are diverse depending mainly on vegetation type and frequency of fire. The aim of this study was to evaluate the effects of wildfire on floristic diversity and species composition in three thermo-Mediterranean vegetation types 1) Sacropoterium spinosum phrygana, 2) low formations of Cistus creticus and 3) low formations of Cistus creticus in abandoned terraces. The research was conducted in Enoussa islet, which is located northeastern of Chios Island, in May 2013 (one year after the fire). Vegetation sampling was performed along five transects placed in recently burned and in adjacent unburned sites of each vegetation type. The plant cover and the floristic composition were measured, while diversity, evenness and dominance indices were determined for the vegetation data. Vegetation cover and the floristic diversity were significant lower and higher respectively in burned areas in comparison to the unburned. The woody species followed by the annual grasses and the annual forbs dominated in both burned and unburned areas. However, the woody species were significantly decreased in the burned areas in all vegetation types, while the annual grasses only in the burned areas of Sacropoterium spinosum phrygana and Cistus creticus in abandoned terraces. Inversely, the annual forbs significantly increased in the burned sites of Cistus creticus formations. The highest value of Morisita-Horn Index of similarity between burned and unburned sites (beta diversity) was

  18. The trace-element characteristics of Aegean and Aeolian volcanic arc marine tephra

    Science.gov (United States)

    Clift, Peter; Blusztajn, Jerzy

    1999-10-01

    High-silica volcanic ashes are found within deep-sea sediments throughout the Eastern Mediterranean. Although coring by Ocean Drilling Program has penetrated Lower Pliocene (˜4 Ma) sediments, few ashes older than 400 k.y. have been recovered, suggesting a young initiation to subaerial Aegean Arc volcanism. Ashes derived from the Aegean volcanic front were cored south and east of the arc, and are typified by medium-K, calc-alkaline major-element compositions, contrasting with high-K ashes from the Aeolian Arc found in the Ionian Sea and as far east as Crete. Ion microprobe analysis of individual glass shards shows that all the ashes have a light rare earth element (LREE)-enriched pattern after normalizing against a chondrite standard. Aeolian Arc-derived ashes show greater enrichment than those from the Aegean area. Within the latter set, two groups are discernible, a mildly enriched set similar to the volcanoes of the arc volcanic front, and a more enriched group corresponding to lavas from the backarc region or possible from western Anatolia. Multi-element `spider diagrams' also show a bimodal division of enriched and depleted Aegean ashes, possibly caused by source depletion due to melt extraction in the Aegean backarc followed by remelting under the volcanic front. Relative Nb depletion, a characteristic of arc volcanism, is seen to be modest in Aegean and non-existent in Aeolian ashes. Using B/Be as a proxy for the flux of material from the subducting slab, this influence is seen to be low in the Aeolian Arc but higher than at Vesuvius. B/Be is higher again in the Aegean Arc. These differences may reflect the rate of subduction in each system. Data suggest caution is required when correlating ashes solely on the basis of major elements, as alkaline ashes from the central part of the study may be derived from Italy or from the Aegean backarc.

  19. A multi disciplinary overview of factors controlling on meiofauna assemblages around Maden and Alibey islands in Ayvalik (Balikesir, Eastern Aegean Sea)

    Science.gov (United States)

    Meriç, Engin; Avsar, Niyazi; Nazik, Atike; Yokes, Baki; Barut, Ipek F.; Suner, Fikret; Sarı, Erol; Eryılmaz, Mustafa; Yucesoy-Eryılmaz, Fulya; Dora, Özcan; Kam, Erol; Dinçer, Feyza

    2017-05-01

    In coastal parts of the study areas, heavy metals containing ground water flows along the faults and fractures and reaches at sea. In these contaminated waters, morphologically abnormal individuals of the affected meiofauna (benthic foraminifera, ostracod, mollusc) can be found. Three cores were taken from the seafloor in the four separate stations that are located in NW of Ayvalık village, around Alibey and Maden islands, and one core of each three core groups was studied in order to investigate the aforementioned morphological affects on the recent meiofauna, which have been inhibited in those contaminated waters. Lead, manganese, hematite and limonite deposits with small reserves were present in Alibey, Maden and Küçük (Small) Maden islands. Morphological changes and coloring were observed in tests of large number of Peneroplis, Lobatula, Ammonia and Elphidium samples collected from these areas. This observation vindicates impact of heavy metals onto the foraminifera assemblages. Heavy metals and other chemical and radioactive elements found in the surrounding country side have been naturally transported into the adjacent sea water during the past and present. The aim of this study is to figure out the effects of the chemical and radioactive elements, which were carried from the land on the meiofaunal (benthic foraminifera, ostracod and mollusc) assemblages.

  20. An integrated multi-parameter monitoring approach for the quantification and mitigation of the climate change impact on the coasts of Eastern Crete, S. Aegean Sea (Project AKTAIA)

    Science.gov (United States)

    Ghionis, George; Alexandrakis, George; Karditsa, Aikaterini; Sifnioti, Dafni; Vousdoukas, Michalis; Andreadis, Olympos; Petrakis, Stelios; Poulos, Serafim; Velegrakis, Adonis; Kampanis, Nikolaos; Lipakis, Michalis

    2014-05-01

    The AKTAIA project aims at the production of new knowledge regarding the forms of manifestation of the climate change and its influence on the stability and evolution of the coastal landforms along the shoreline of eastern Crete (approximate length: 757 km), taking into account the various aspects of human intervention. Aerial photographs, satellite images and orthophotomaps have been used to produce a detailed coastline map and to study the morphological characteristics of the coastal zone of Eastern Crete. More than 100 beach zones have been visited during three field campaigns, which included geomorphological and human intervention mapping, topographic, meteorological and oceanographic measurements and sedimentological sampling and observations. In addition, two pilot sites (one in the north and one in the south part of Crete) are being monitored, via the installation of coastal video monitoring systems, shore-based meteorological stations and wave-tide recorders installed in the nearshore zone. Detailed seafloor mapping with the use of side scan sonar and scuba diving and bathymetric surveys were conducted in the two pilot sites. Meteorological and oceanographic data from all existing land-based meteorological stations, oceanographic buoys and the ERA-interim dataset are used to determine the wind and wave climate of each beach. The collected climatic, sedimentological and coastal environmental data are being integrated in a GIS database that will be used to forecast the climatic trends in the area of Crete for the next decades and to model the impact of the climatic change on the future evolution of the coastal zone. New methodologies for the continuous monitoring of land-sea interaction and for the quantification of the loss of sensitive coastal zones due to sea-level rise and a modified Coastal Vulnerability Index for a comparative evaluation of the vulnerability of the coasts are being developed. Numerical modelling of the nearshore hydrodynamics and the

  1. New constraints on the active tectonic deformation of the Aegean

    Science.gov (United States)

    Nyst, M.; Thatcher, W.

    2004-01-01

    Site velocities from six separate Global Positioning System (GPS) networks comprising 374 stations have been referred to a single common Eurasia-fixed reference frame to map the velocity distribution over the entire Aegean. We use the GPS velocity field to identify deforming regions, rigid elements, and potential microplate boundaries, and build upon previous work by others to initially specify rigid elements in central Greece, the South Aegean, Anatolia, and the Sea of Marmara. We apply an iterative approach, tentatively defining microplate boundaries, determining best fit rigid rotations, examining misfit patterns, and revising the boundaries to achieve a better match between model and data. Short-term seismic cycle effects are minor contaminants of the data that we remove when necessary to isolate the long-term kinematics. We find that present day Aegean deformation is due to the relative motions of four microplates and straining in several isolated zones internal to them. The RMS misfit of model to data is about 2-sigma, very good when compared to the typical match between coseismic fault models and GPS data. The simplicity of the microplate description of the deformation and its good fit to the GPS data are surprising and were not anticipated by previous work, which had suggested either many rigid elements or broad deforming zones that comprise much of the Aegean region. The isolated deforming zones are also unexpected and cannot be explained by the kinematics of the microplate motions. Strain rates within internally deforming zones are extensional and range from 30 to 50 nanostrain/year (nstrain/year, 10-9/year), 1 to 2 orders of magnitude lower than rates observed across the major microplate boundaries. Lower strain rates may exist elsewhere withi the microplates but are only resolved in Anatolia, where extension of 13 ?? 4 nstrain/ year is required by the data. Our results suggest that despite the detailed complexity of active continental deformation

  2. Changes in Nitrogen to Phosphorus ratio in the Inner Saronikos Gulf (West Aegean Sea) in relation to the operation of the Sewage Treatment Plant of Athens, Greece

    Science.gov (United States)

    Psyllidou-Giouranovits, Rosa

    2013-04-01

    In this work we provide an overview of nitrogen (N) to phosphorus (P) ratio in the inner Saronikos gulf as it has changed over the last twenty five (25) years in relation to the sewage discharges from the Sewage Treatment Plant of Athens in Psittalia Island. Saronikos gulf receives effluents from Athens Metropolitan area (population over 5 million). Until 1994, domestic and industrial sewage of Athens was discharged untreated into the surface water layer of Keratsini and Elefsis bay, whereas, after 1994, the sewage of the Athens Metropolitan area were primarily treated in Psitallia Sewage Treatment Plant and discharged in the inner Saronikos Gulf. Additionally, the secondary stage of the Psittalia Sewage Plant operated in the end of 2004 affecting the nitrogen to phosphorus (DIN:P) ratio (DIN stands for nitrate+nitrite+ammonium). The treated effluent plume frorm Psittalia Sewage Treatment Plant is trapped within the seasonal pycnocline developed during May-November, whereas, during the mixing period (December-April) it reaches the sea-surface. During the last 25 years, significant temporal variation of nutrient concentrations has been observed which has revealed an increase of the DIN:P ratio near the Psittalia Sewage Treatment Plant. In the vicinity of the sewage outfall in Psittalia, DIN:P ratio in the deep layer (30m-bottom) did not show significant variation between the two periods: before and after the operation of the Sewage Treatment Plant (12.9 before the operation of the sewage treatment and 13.3 after the operation of the sewage treatment) showing that inorganic nitrogen and phosphate changed almost with the same rate. However, the limiting factor for phytoplankton growth remains nitrogen. On the contrary, significant increase of DIN:P ratio was observed in the surface layer between the two periods, during summer (stratified period). DIN:P increased from 5.9 for the period 1987-1995 (before the Sewage Treatment Plant operation) to 19.6 for the period 1995

  3. Geometry of the Aegean Benioff zones

    Directory of Open Access Journals (Sweden)

    M. Knapmeyer

    1999-06-01

    Full Text Available The morphology of the Aegean Benioff zone was reconstructed using 1366 hypocentres from the PDE catalogue 1973-1997. Two such zones are identified under the Aegean area, a large one (Main Aegean Subduction, MAS spanning the whole Hellenic arc and a smaller and younger one under the Western Peloponnesus. The geometry of the MAS suggests that it blocks its own subduction and, therefore, causes the development of the smaller western zone as a result of a step back process in the Pliocene.

  4. Activation of the operational ecohydrodynamic model (3-D CEMBS – the hydrodynamic part

    Directory of Open Access Journals (Sweden)

    L. Dzierzbicka-Głowacka

    2012-07-01

    Full Text Available The paper presents a description of the hydrodynamic part of the coupled ice-ocean model that also includes ecosystem predictive model for evaluation of the condition of the marine environment and the Baltic ecosystem, as well as a preliminary empirical verification of the operational hydrodynamic model based on the POP code in order to determine the consistence between the results obtained from the model and experimental results for the sea surface temperature.

    The current Baltic Sea model is based on the Community Earth System Model (CESM from NCAR – National Center for Atmospheric Research. CESM was adopted for the Baltic Sea as a coupled sea-ice model. It consists of the Community Ice Code (CICE model, version 4.0 and the Parallel Ocean Program (POP, version 2.1. The models are coupled through the coupler (CPL7, which is based on the Model Coupling Toolkit (MCT routines. The current horizontal resolution is about 2 km (1/48 degrees. The ocean model has 21 vertical levels. The driver time step is 1440 s and it is also coupling the time step. The ocean model time step is about 480 s (8 min. Currently, the model is forced by fields from the European Center for Medium Weather Forecast. In the operational mode, 48-h atmospheric forecasts are used, which are supplied by the UM model of the Interdisciplinary Centre for Mathematical and Computational Modelling of the Warsaw University. The model of the marine ecosystem is the right tool for monitoring the state and bioproductivity of the marine ecosystem and forecasting the physical and ecological changes in the studied basin.

  5. Submarine volcanoes along the Aegean volcanic arc

    Science.gov (United States)

    Nomikou, Paraskevi; Papanikolaou, Dimitrios; Alexandri, Matina; Sakellariou, Dimitris; Rousakis, Grigoris

    2013-06-01

    The Aegean volcanic arc has been investigated along its offshore areas and several submarine volcanic outcrops have been discovered in the last 25 years of research. The basic data including swath bathymetric maps, air-gun profiles, underwater photos and samples analysis have been presented along the four main volcanic groups of the arc. The description concerns: (i) Paphsanias submarine volcano in the Methana group, (ii) three volcanic domes to the east of Antimilos Volcano and hydrothermal activity in southeast Milos in the Milos group, (iii) three volcanic domes east of Christiana and a chain of about twenty volcanic domes and craters in the Kolumbo zone northeast of Santorini in the Santorini group and (iv) several volcanic domes and a volcanic caldera together with very deep slopes of several volcanic islands in the Nisyros group. The tectonic structure of the volcanic centers is described and related to the geometry of the arc and the neotectonic graben structures that usually host them. The NE-SW direction is dominant in the Santorini and Nisyros volcanic groups, located at the eastern part of the arc, where strike-slip is also present, whereas NW-SE direction dominates in Milos and Methana at the western part, where co-existence of E-W disrupting normal faults is observed. The volcanic relief reaches 1100-1200 m in most cases. This is produced from the outcrops of the volcanic centers emerging usually at 400-600 m depth and ending either below sea level or at high altitudes of 600-700 m on the islands. Hydrothermal activity at relatively high temperatures observed in Kolumbo is remarkable whereas low temperature phenomena have been detected in the Santorini caldera around Kameni islands and in the area southeast of Milos. In Methana and Nisyros, hydrothermal activity seems to be limited in the coastal areas without other offshore manifestations.

  6. Towards configuring the neolithisation of Aegean Turkey

    Directory of Open Access Journals (Sweden)

    Çiler Çilingiroğlu

    2013-12-01

    Full Text Available Increasing field work in the  ̇Izmir region has produced much sought tangible evidence about the ways in which food-producing communities emerged in the Aegean. Focusing on the archaeological and zooarchaeological data from Ulucak and neighboring sites, the authors discuss the possible mechanisms of initial farmer-herder dispersals into the region. The authors stress that the lack of pre-Neolithic strata in the eastern Aegean impedes a full understanding of forager-farmer interactions in the early Holocene.

  7. Earthquakes increase hydrothermal venting and nutrient inputs into the Aegean

    Science.gov (United States)

    Dando, P. R.; Hughes, J. A.; Leahy, Y.; Taylor, L. J.; Zivanovic, S.

    1995-05-01

    Areas of submarine gas and water venting around the island of Milos, in the Hellenic volcanic island arc, were mapped. Water samples were collected from five stations in the geothermally active Paleohori Bay on 15 March 1992. Seismic events, of M s 5.0 and 4.4, occurred south of the Bay on 20 March and the sampling was repeated after these. Phosphate and manganese in the water column increased by 360% after the seismic activity. Analysis of water samples collected from gas and water seeps and of interstitial water from sediment cores showed that the hot sediment in the Bay was enriched in phosphate, to a mean concentration of 65 μmol l -1 in the interstitial water. The number of geothermally active areas in the Aegean, together with the extent of venting and the frequency of earthquakes suggests that the hydrothermal areas may be an important source of phosphate in this oligotrophic Sea.

  8. Predatory mite fauna in Aegean vineyards

    OpenAIRE

    GÖVEN, Mehmet Ali; ÇOBANOĞLU, Sultan; GÜVEN, Bilgin

    2010-01-01

    This study was carried out between 1997-2004 in vineyard areas in Manisa, İzmir, Denizli, Muğla and Çanakkale (Bozcaada) provinces of the Aegean region to determine biological control possibilities against phytophagous mites. Sampling was conducted from May to October. Most of the vineyards were sampled three times during the growing season and 50 leaves were collected randomly in each vineyard. Colomerus vitis (Pagenstecher) and Calepitrimerus vitis (Nalepa)were determined ...

  9. Off-shore Wind Atlas of the Central Aegean Sea: A simple comparison of NCEP/NCAR RE-analysis data, QuickSCAT and ENVISAT Synthetic Aperture Radar (SAR) by use of Wind Atlas Method

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Hasager, Charlotte Bay; Karagali, Ioanna

    2012-01-01

    Offshore wind energy is progressing rapidly in many parts of the world including Europe. While our understanding of offshore wind is growing parallel to that, most of the offshore wind development is located in shallow or transitional waters. Deep, open sea was never preferred by developers due t...

  10. Accessibility of Peripheral Regions: Evidence from Aegean Islands (Greece

    Directory of Open Access Journals (Sweden)

    Ioannis Spilanis

    2012-11-01

    Full Text Available Islands, especially smaller ones, are characterized by discontinuity of space and are considered as some of the least accessible areas. In this paper, we seek to shed light on the accessibility problems that islands face from the point of view of island residents. This shift in emphasis considers additional aspects to accessibility that include the availability of connections to access services required to cover the needs of island residents and the different destinations where these may be available, and the time that one may have to spend to get to these destinations in order to use these services. An alternative measure of accessibility is proposed, based on the time required to travel; this is then applied to three different Greek islands in the Aegean Sea. The accessibility of the residents of these islands to selected services is compared with that of settlements in continental Greece of similar population and distance to the capital Athens. The findings clearly demonstrate the adversities that island residents have to face, especially for smaller islands, where accessing selected services may require as many as four destinations, with virtual distances 4 to 6 times longer than ‘real distances’.

  11. Climate variability and socio-environmental changes in the northern Aegean (NE Mediterranean) during the last 1500 years

    Science.gov (United States)

    Gogou, Alexandra; Triantaphyllou, Maria; Xoplaki, Elena; Izdebski, Adam; Parinos, Constantine; Dimiza, Margarita; Bouloubassi, Ioanna; Luterbacher, Juerg; Kouli, Katerina; Martrat, Belen; Toreti, Andrea; Fleitmann, Dominik; Rousakis, Gregory; Kaberi, Helen; Athanasiou, Maria; Lykousis, Vasilios

    2016-04-01

    We provide new evidence on sea surface temperature (SST) variations and paleoceanographic/paleoenvironmental changes over the past 1500 years for the north Aegean Sea (NE Mediterranean). The reconstructions are based on multiproxy analyses, obtained from the high resolution (decadal to multi-decadal) marine record M2 retrieved from the Athos basin. Reconstructed SSTs show an increase from ca. 850 to 950 AD and from ca. 1100 to 1300 AD. A cooling phase of almost 1.5 °C is observed from ca. 1600 AD to 1700 AD. This seems to have been the starting point of a continuous SST warming trend until the end of the reconstructed period, interrupted by two prominent cooling events at 1832 ± 15 AD and 1995 ± 2 AD. Application of an adaptive Kernel smoothing suggests that the current warming in the reconstructed SSTs of the north Aegean might be unprecedented in the context of the past 1500 years. Internal variability in atmospheric/oceanic circulations systems as well as external forcing as solar radiation and volcanic activity could have affected temperature variations in the north Aegean Sea over the past 1500 years. The marked temperature drop of approximately ~2°C at 1832 ± 15 yr AD could be related to the 1809 ΑD 'unknown' and the 1815 AD Tambora volcanic eruptions. Paleoenvironmental proxy-indices of the M2 record show enhanced riverine/continental inputs in the northern Aegean after ca. 1450 AD. The palaeoclimatic evidence derived from M2 record is combined with a socio-environmental study of the history of the north Aegean region. We show that the cultivation of temperature-sensitive crops, i.e. walnut, vine and olive, co-occurred with stable and warmer temperatures, while its end coincided with a significant episode of cooler temperatures. Periods of agricultural growth in Macedonia coincide with periods of warmer and more stable SSTs, but further exploration is required in order to identify the causal links behind the observed phenomena. The Black Death likely

  12. box modeling of the eastern mediterranean sea

    Science.gov (United States)

    Ashkenazy, Y.; Stone, P. H.

    2003-04-01

    Recently (~1990) a new source of deep water formation in the Eastern Mediterranean was found in the southern part of the Aegean sea. Till then, the only source of deep water formation in the Eastern Mediterranean was in the Adriatic sea; the rate of the deep water formation of the new Aegean source is 1Sv=10^6m^3/s, three times larger then the Adriatic source. We develop a simple 3 box-model to study the stability of the thermohaline circulation of the Eastern Mediterranean sea. The 3 boxes represent the Adriatic sea, Aegean sea, and the Ionian sea. The boxes exchange heat and salinity and may be described by a set of nonlinear differential equations. We analytically analyze these equations and find that the system may have one, two, or four stable flux states. We consider two cases for which the temperatures of the boxes are (i) fixed or (ii) variable. After setting the parameters to correspond to the Eastern Mediterranean we find that the system has two stable states, one with (i) two thermally dominant sources of deep water formation in the Adriatic and Aegean and the other with (ii) a salinity dominant source of deep water formation in the Adriatic and a thermally dominant source in the Aegean. While the Adriatic thermally dominant source is comparable to the observed flux of 0.3Sv the Aegean source has much smaller flux than the observed value. This situation is analogous to the state of the thermohaline circulation pre 1990 where the only source of deep water formation was in the Adriatic. If we decrease the atmospheric temperature of the Aegean box by 2C in accordance with recent observations, we find that the deep water formation of the Aegean increases significantly to a value comparable to the recently observed flux.

  13. Evolutionary processes in a continental island system: molecular phylogeography of the Aegean Nigella arvensis alliance (Ranunculaceae) inferred from chloroplast DNA.

    Science.gov (United States)

    Bittkau, C; Comes, H P

    2005-11-01

    Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of past fragmentation, dispersal, and genetic drift on taxon diversification. We used phylogeographical (nested clade) and population genetic analyses to elucidate the relative roles of these processes in the evolutionary history of the Aegean Nigella arvensis alliance (= 'coenospecies'). We surveyed chloroplast DNA (cpDNA) variation in 455 individuals from 47 populations (nine taxa) of the alliance throughout its core range in the Aegean Archipelago and surrounding mainland areas of Greece and Turkey. The study revealed the presence of three major lineages, with largely nonoverlapping distributions in the Western, Central, and Eastern Aegean. There is evidence supporting the idea that these major lineages evolved in situ from a widespread (pan-Aegean) ancestral stock as a result of multiple fragmentation events, possibly due to the influence of post-Messinian sea flooding, Pleistocene eustatic changes and corresponding climate fluctuations. Over-sea dispersal and founder events appear to have played a rather insignificant role in the group's history. Rather, all analytical approaches identified the alliance as an organism group with poor seed dispersal capabilities and a susceptibility to genetic drift. In particular, we inferred that the observed level of cpDNA differentiation between Kikladian island populations of Nigella degenii largely reflects population history, (viz. Holocene island fragmentation) and genetic drift in the near absence of seed flow since their time of common ancestry. Overall, our cpDNA data for the N. arvensis alliance in general, and N. degenii in particular, indicate that historical events were important in determining the phylogeographical patterns seen, and that genetic drift has historically been relatively more influential on population structure than has cytoplasmic gene flow.

  14. Monitoring seismic velocity changes caused by the 2014 Northern Aegean earthquake using continuous ambient noise records

    Science.gov (United States)

    Evangelidis, Christos; Daskalakis, Emmanouil; Tsogka, Chrysoula

    2016-04-01

    The 24 May 2014 Northern Aegean earthquake (6.9 Mw), an event on the Northern Aegean Trough (NAT), ruptured on two different fault segments with a total ruptured length of ~100 km. For the second delayed segment, rupture propagated eastward from the hypocenter for ˜65 km with a supershear velocity (5.5 km/s). Low-aftershock seismicity on the supershear segment implies a simple and linear fault geometry there. An effort to monitor temporal seismic velocity changes across the ruptured area of the Northern Aegean earthquake is underway. In recent years, neighboring seismic broadband stations near active faults have been successfully used to detect such changes. The crosscorrelation functions (CCF) of ambient noise records between stations yields the corresponding traveltimes for those inter-station paths. Moreover, the auto-correlation functions (ACF) at each station produce the seismic responce for a coincident source and receiver position. Possible temporal changes of the measured traveltimes from CCFs and ACFs correspond to seismic velocity changes. Initially, we investigate the characteristics and sources of the ambient seismic noise as recorded at permanent seismic stations installed around NAT at the surrounding islands and in mainland Greece and Turkey. The microseismic noise levels show a clear seasonal variation at all stations. The noise levels across the double frequency band (DF; period range 4-8 s) reflect the local sea-weather conditions within a range of a few hundred kilometers. Three years of continuous seismic records framing the main shock have been analysed from ~15 stations within a radius of 100 km from the epicentre. We observe a clear decrease of seismic velocities most likely corresponding to the co-seismic shaking. The spatial variation of this velocity drop is imaged from all inter-station paths that correspond to CCF measurements and for station sites that correspond to ACF measurements. Thus, we explore a possible correlation between co

  15. On Entrepreneurs and Entrepreneurship of the Olive-oil Economy in the Aegean: The Case of Lesvos Island

    Directory of Open Access Journals (Sweden)

    Evridiki Sifneos

    2005-01-01

    Full Text Available This article summarizes the conclusions of a study on entrepreneurial activities related to the cycle of the olive-oil economy in Lesvos, an island in the North-Eastern Aegean, from the eighteenth century until the middle of the twentieth century. It is based on research and observations drawn from a multiform primary material, such as companies' records, communal and family archives, consular and administrative reports, as well as secondary sources which allow comparisons with other oleiferous regions and connect the economy of Lesvos to the broader Aegean and Mediterranean environment.It points out that the single cultivation phenomenon, though associated to the economy of risk, obeyed to the market's command and was prepared by the abolition of the governor's monopoly on the oil trading and the consequent opening of the market. This enabled the Christian ottoman subjects to develop the administration of intensive olive growing, mechanized oil extraction and trade expansion. Olive oil and soap were the two basic commodities of the island's export revenues that were commercialised, despite their low quality, into a wide range of port and island markets of the Asia Minor coast, the Aegean islands and the Black Sea. Moreover, the article explores the type of commercial and industrial enterprises and the characteristics of the olive-cycle entrepreneurs. It concludes with the commercial crisis suffered from the major political and economic changes of the twentieth century and the consequent reorientation of Lesvos' businessmen towards Crete and Piraeus, the olive manufacturing centres of the Neohellenic state.

  16. Tomographic image of the crust and uppermost mantle of the Ionian and Aegean regions

    Directory of Open Access Journals (Sweden)

    G. N. Stavrakakis

    1997-06-01

    Full Text Available We present a tomographic view of the crust and uppermost mantle beneath the Central Mediterranean area obtained from P-wave arrival times of regional earthquakes selected from the ISC bulletin. The P-wave velocity anomalies are obtained using Thurber's algorithm that jointly relocates earthquakes and computes velocity adjustments with respect to a starting model. A specific algorithm has been applied to achieve a distribution of epicentres as even as possible. A data set of 1009 events and 49072 Pg and Pn phases was selected. We find a low velocity belt in the crust, evident in the map view at 25 km of depth, beneath the Hellenic arc. A low velocity anomaly extends at 40 km of depth under the Aegean back arc basin. High velocities are present at Moho depth beneath the Ionian sea close to the Calabrian and Aegean arcs. The tomographic images suggest a close relationship between P-wave velocity pattern and the subduction systems of the studied area.

  17. The Aegean in the Early 7th Millennium BC: Maritime Networks and Colonization.

    Science.gov (United States)

    Horejs, B; Milić, B; Ostmann, F; Thanheiser, U; Weninger, B; Galik, A

    The process of Near Eastern neolithization and its westward expansion from the core zone in the Levant and upper Mesopotamia has been broadly discussed in recent decades, and many models have been developed to describe the spread of early farming in terms of its timing, structure, geography and sociocultural impact. Until now, based on recent intensive investigations in northwestern and western Anatolia, the discussion has mainly centred on the importance of Anatolian inland routes for the westward spread of neolithization. This contribution focuses on the potential impact of east Mediterranean and Aegean maritime networks on the spread of the Neolithic lifestyle to the western edge of the Anatolian subcontinent in the earliest phases of sedentism. Employing the longue durée model and the concept of 'social memory', we will discuss the arrival of new groups via established maritime routes. The existence of maritime networks prior to the spread of farming is already indicated by the high mobility of Epipalaeolithic/Mesolithic groups exploring the Aegean and east Mediterranean seas, and reaching, for example, the Cyclades and Cyprus. Successful navigation by these early mobile groups across the open sea is attested by the distribution of Melian obsidian. The potential existence of an additional Pre-Pottery Neolithic (PPN) obsidian network that operated between Cappadocia/Cilicia and Cyprus further hints at the importance of maritime coastal trade. Since both the coastal and the high seas networks were apparently already well established in this early period, we may further assume appropriate knowledge of geographic routes, navigational technology and other aspects of successful seafaring. This Mesolithic/PPN maritime know-how package appears to have been used by later groups, in the early 7th millennium calBC, exploring the centre of the Anatolian Aegean coast, and in time establishing some of the first permanent settlements in that region. In the present paper, we

  18. Crustal tomography of the Aegean-Anatolian domain using noise cross-correlations

    Science.gov (United States)

    Hubans, Fabien; Paul, Anne; Campillo, Michel; Karabulut, Hayrullah; Hatzidimitriou, Panagiotis

    2010-05-01

    Data of more than 150 temporary and permanent broadband seismological stations deployed in the Aegean-Anatolian domain between May 2007 and May 2009 are grouped in the SIMBAAD (Seismic Imaging of the Mantle Across the Anatolian Domain) dataset. We compute noise cross-correlations between all station pairs on a 1.5-yr duration. We obtain more than 11.000 correlations for each component of the cross-correlation tensor. We apply a MFA (Multiple Filter Analysis) method to measure group velocity dispersion curves of Rayleigh waves on 4 components of the correlation tensor (ZZ, ZR, RZ, RR) and of Love waves on the TT component, both in positive and negative times. According to the theory, a noise cross-correlation converges to the Green function if noise sources are randomly distributed around the station pair. If this condition is fulfilled, the cross-correlation should be symmetrical in time. We compare group velocity measurements between positive and negative times to evaluate the convergence of each cross-correlation to the Green function. The quality of the symmetry is used to weight the time measurements in the inversion for group velocity maps. In the last step, Rayleigh wave group velocity data are inverted for a 3-D model of S-wave velocity. This processing gives an image of the crustal structure in the area [37-41°N ; 23-33°E] with a horizontal resolution of 60 to 200 km depending on depth and station coverage. The shallowest layers clearly display the present-day thick sedimentary basins (Axios, Thrace, Marmara, Bay of Antalya, ...) and older sedimentary nappes (Lycian nappes, Miocene sediments in the Kirsehir block) as strong low velocity anomalies. At larger depth, Southwestern Anatolia is characterized by a broad low velocity anomaly which contrasts with the higher velocities of the Aegean Sea. We clearly image a West to East increase of Moho depth from 20-25 km in the Aegean Sea to 35 km in the Anatolian plateau. This increase located between 27°E and

  19. Zooplankton community dynamics in the N. Aegean front (E. Mediterranean in the winter spring period

    Directory of Open Access Journals (Sweden)

    I. SIOKOU

    2015-01-01

    Full Text Available Zooplankton community composition was studied in the North Aegean frontal area in the winter-spring period along a trophic gradient going from the less saline and cold modified Black Sea water to the high salinity and temperature waters of Levantine origin. Samples were collected at the upper 100 m of three stations positioned along this gradient by using three nets with different mesh sizes (45 μm, 200 μm and 500 μm. Τhe community composition (all sizes was differentiated along the gradient with smoother seasonal succession and higher diversity with increasing oligotrophy and salinity. The temporal variability of the community composition revealed significant changes in the January-April period as well as gradual decrease of diversity index values at the station positioned within the front.  The major characteristic at this station was the abrupt increment and dominance of Centropages typicus in April, especially within the layer occupied by the modified Black Sea water. Significant difference in the community composition between March and April was a common feature in the whole study area and for all zooplankton fractions, though not of the same strength. The inflow of the Black Sea water and the trophic gradient were found to be important factors for the observed temporal variability and its spatial differentiation, while changes in the phytoplankton and protozoa abundance and community composition could account for the seasonal succession in species dominance.

  20. Early Neolithic settlement patterns and exchange networks in the Aegean

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    Agathe Reingruber

    2011-12-01

    Full Text Available The Neolithisation process is one of the major issues under debate in Aegean archaeology, since the description of the basal layers of Thessalian tell-settlements some fifty years ago. The pottery, figurines or stamps seemed to be of Anatolian origin, and were presumably brought to the region by colonists. The direct linking of the so-called ‘Neolithic Package’ with groups of people leaving Central Anatolia after the collapse of the Pre-Pottery Neolithic B resulted in the colonisation model of the Aegean. This view is not supported by results obtained from natural sciences such as archaeobotany, radiocarbon analyses, and neutron activation on obsidian. When theories of social networks are brought into the discussion, the picture that emerges becomes much more differentiated and complex.

  1. The shape of the Aegean MCC's, Insights from 3D numerical modelling

    Science.gov (United States)

    Le Pourhiet, L.; Denèle, Y.; Huet, B.; Jolivet, L.

    2010-12-01

    The Aegean sea is a back arc basin in which the continental lithosphere has been stretched through the tertiary leaving several diachronous belts of Metamorphic Core Complexes (MCCs). The Aegean MCCs present two classes of shapes. Some are elongated in the direction of the lineation (A-type e.g. Naxos, Paros..) while the others are elongated in a direction normal to the lineation (B-type e.g. Tinos, Evvia ...). While it is well established from 1 and 2D modeling that MCC's forms when the lower crust is weak, the reason for the diversity of shape remains an open question. The A-type domes are not only elongated in shape; their P-T-t paths indicate a clear phase of warming during the exhumation and they also present migmatites (which are not observed in the other islands). Several hypothesis may be drawn. The elongated domes could result from 1) the competition of boudinage versus normal constriction folding, 2) lateral variation of the thickness or the temperature of the crust resulting in local buoyant instability (R-T instability) or 3) lateral gradient of deformation. This contribution presents the preliminary results obtained with thermo-mechanical models in which we test the influence of a local plutonic intrusions, along strike variation of extensional rate, and lateral boundary condition (normal shortening or extension) on the shape of the domes. As this problem is inherently three dimensional, the models were computed on our computer cluster using Gale/Underworld an ALE method with visco-plastic temperature dependent rheologies.

  2. MULTIPLE LEVELS IN THE AEGEAN BRONZE AGE WORLD-SYSTEM

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    Nick Kardulias

    2015-08-01

    Full Text Available Aegean societies in the third and second millennia B.C. developed complex economics based on the accumulation of substantial agricultural surpluses, craft specialization, and intricate distribution systems. The trade items included both utilitarian and luxury goods. To place these activities in a proper context, this paper initially evaluates the world systems literature as it relates to antiquity. The paper then presents some specific evidence to support the contention that the Aegean BA economy was an adjunct to an Eastern Mediterranean world system. While Wallerstein's model offers valuable insights into the operation of trade networks, his approach has certain limitations. The paper explores some of these limitations, in particular the absence of periphery dependence on core areas that is a hallmark of modern capitalist systems, discusses revisions suggested by other scholars, and demonstrates the validity of the altered model with data from the Aegean. The evidence suggests the existence of a system with local, intraregional, and extraregional components. Finally, the paper also suggests that the world systemsapproach needs to place greater emphasis on production, not just exchange, as the crucial nexus of economic activity.

  3. The Contacts of the Hittites with the Aegean Peoples

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    Mladen Horvat

    2003-07-01

    Full Text Available id the Hittites, a landlocked nation from central Anatolia, have any contacts with the Aegean region and its peoples? This has been a hotly contested issue ever since 1924, when E. Forrer claimed to have discovered a reference to Homeric Greeks in Hittite texts mentioning a country called Ahhiyawa. Almost as soon as the theory appeared, it was refuted by many prominent Hittitologists, most notably F. Sommer and A. Goetze, who claimed Ahhiyawa was just one of the Anatolian principalities. But there were also those who concurred with Forrer's claims - F. Schachermeyer and G. L. Huxley. Some scholars later propounded their own theories about the location of Ahhiyawa, placing it in the area of the Troad or Thrace. Recent scholarship mostly agrees with Guterbock that Ahhiyawa must have had some connection with the Mycenaeans, but not all have been persuaded. There are several Hittite documents in which Ahhiyawa appears. The earliest of there is the so-called Indictment of Madduwata. It dates to the beginning of the 14''' century B. C. and recounts Hittite dealings with a certain Madduwata, forced to flee his country by Attarsiya, whom the Hittites called Man of Ahhiya(wa. Madduwata was installed as a Hittite vassal ruler somewhere in southwestern Anatolia; however, he proved to be an ungrateful and overambitious person, who caused serious trouble for his overlord by attacking Hittite possessions in what appears to have been the area of classical Lycia and Caria. Later he even invaded Cyprus in alliance with his former enemy Attarsiya. The next reference to Ahhiyawa comes from the time of the Hittite king Mursilli, who reigned in the last quarter of the 14''' century B. C. He conquered the country of Arzawa, which lay in the area of classical Lydia, with its capital Apasa (classical Ephesus. Relying on the king of Ahhiyawa, it engaged in hostilities against the Hittites and incited the land of Millawanda (classical Miletus to rebellion, but was

  4. Pelagic-benthic coupling and diagenesis of nucleic acids in a deep-sea continental margin and an open-slope system of the Eastern Mediterranean.

    Science.gov (United States)

    Dell'anno, Antonio; Corinaldesi, Cinzia; Stavrakakis, Spyros; Lykousis, Vasilis; Danovaro, Roberto

    2005-10-01

    Downward fluxes of nucleic acids adsorbed onto settling particles play a key role in the supply of organic phosphorus and genetic material to the ocean interior. However, information on pelagic-benthic coupling, diagenesis, and processes controlling nucleic acid preservation in deep-sea sediments is practically nonexistent. In this study, we compared nucleic acid fluxes, sedimentary DNA and RNA concentrations, and the enzymatically hydrolyzable fraction of DNA in a bathyal continental margin (North Aegean Sea) and an open-sea system (South Aegean Sea) of the Eastern Mediterranean. The two systems displayed contrasting patterns of nucleic acid fluxes, which increased significantly with depth in the North Aegean Sea and decreased with depth in the South Aegean Sea. These results suggest that in continental margin and open-ocean systems different processes control the nucleic acid supply to the sea floor. Differences in nucleic acid fluxes were reflected by nucleic acid concentrations in the sediments, which reached extremely high values in the North Aegean Sea. In this system, a large fraction of DNA may be buried, as suggested by the large fraction of DNA resistant to nuclease degradation and by estimates of burial efficiency (ca. eight times higher in the North than in the South Aegean Sea). Overall, the results reported here suggest that the preservation of DNA in deeper sediment layers may be favored in benthic systems characterized by high sedimentation rates.

  5. The examination of climate comfortable conditions in terms of coastal tourism on the Aegean Region coastal belt

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    Yüksel Güçlü

    2010-03-01

    Full Text Available It is important that climate comfortable conditions are within presumed threshold values with respect to tourism activities in the form that people rest in a healthy environment. The climatical elements bearing importance for climate comfortable conditions in general sunshine duration, temperature, relative humidity, wind and precipitation have been taken into consideration for this purpose. The purpose of this study is to examine of the climate comfortable conditions in respect to tourism on the Aegean Region coastal belt of Turkey. In this study, TCI, THI and SSI indices have been used for determining climate comfort conditions. The best climate comfortable conditions in terms of coastal tourism are seen May-June and September-October periods in the study area. Climate comfortable decreases due to high temperature and relative humidity in July-August period. November-April period is not appropriate for the coastal tourism. The favourable period for sea bathing is seen between 9 June-26 September.

  6. Effects of fragmentation on genetic diversity in island populations of the Aegean wall lizard Podarcis erhardii (Lacertidae, Reptilia).

    Science.gov (United States)

    Hurston, H; Voith, L; Bonanno, J; Foufopoulos, J; Pafilis, P; Valakos, E; Anthony, N

    2009-08-01

    Landbridge islands offer unique opportunities for understanding the effects of fragmentation history on genetic variation in island taxa. The formation of islands by rising sea levels can be likened to a population bottleneck whose magnitude and duration is determined by island area and time since isolation, respectively. The Holocene landbridge islands of the Aegean Sea (Greece) were formed since the last glacial maximum and constitute an ideal system for disentangling the effects of island area, age and geographic isolation on genetic variability. Of the many reptile species inhabiting this island system, the Aegean wall lizard Podarcis erhardii is an excellent indicator of fragmentation history due to its widespread distribution and poor over-water dispersal abilities. In this study, we utilize a detailed record of Holocene fragmentation to investigate the effects of island history on wall lizard mitochondrial and nuclear microsatellite diversity. Findings show that the spatial distribution of mitochondrial haplotypes reflects historical patterns of fragmentation rather than geographic proximity per se. In keeping with neutral bottleneck theory, larger and younger islands retain more nuclear genetic variation than smaller, older islands. Conversely, there is no evidence of an effect of isolation by distance or effect of distance to the nearest larger landmass on genetic variability, indicating little gene flow between islands. Lastly, population-specific measures of genetic differentiation are inversely correlated with island area, suggesting that smaller islands exhibit greater divergence due to their greater susceptibility to drift. Taken together, these results suggest that both island area and time since isolation are important predictors of genetic variation and that these patterns likely arose through the progressive fragmentation of ancestral diversity and the ensuing cumulative effects of drift.

  7. Pilot study of intrauterine exposure to methylmercury in Eastern Aegean islands, Greece.

    Science.gov (United States)

    Gibicar, Darija; Horvat, Milena; Nakou, Sheena; Sarafidou, Jasmin; Yager, Janice

    2006-08-31

    A group of islands with a total population of about 200,000 was identified in the Eastern Aegean, where there was evidence to suggest possible increased exposure to methylmercury (MeHg) through consumption of fresh local fish and other seafood from seas bordered by mercury-bearing rock. A feasibility study was conducted to explore the possibility of defining a local population of mother-child pairs in whom to investigate the intrauterine exposure effect. Analysis of 246 hair samples collected from pregnant women and mothers of newborn babies and children under 5 years showed levels of total Hg from 0.046 microg/g to 17.5 microg/g, geometric mean 1.36 microg/g, and of MeHg from 0.031 microg/g to 16.2 microg/g, geometric mean 1.07 microg/g. About 5% of the mothers had hair total Hg levels in excess of 6.00 microg/g. Investigation of dietary habits showed that one-third of the mothers eat fresh local fish at least 3 times weekly, one-third once a week and 10% rarely or never. There was a close association between weekly rates of local fish consumption and hair levels of both total Hg and MeHg. A power calculation determined that a cohort of 3000 mother-child pairs would enable comparison of a high-exposure group (those with the upper 5% of hair MeHg) with a low exposure group (5%, selected from those with the lower 30% of hair MeHg, matched for confounding factors), in order to detect an effect size of 0.35 to 0.45 at a power of 85-95%. It is concluded that the mothers and children in the Eastern Aegean islands studied comprise a population suitable for an epidemiological study of the effects of intrauterine exposure to MeHg via maternal fresh local fish consumption.

  8. Focal mechanisms in the southern Aegean from temporary seismic networks – implications for the regional stress field and ongoing deformation processes

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    W. Friederich

    2014-05-01

    Full Text Available The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 well-constrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini–Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW–SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE–SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east–west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW–SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except

  9. Gonioinfradens paucidentatus (A. Milne Edwards, 1861 (Crustacea, Decapoda, Portunidae: a new alien crab in the Mediterranean Sea

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    M. CORSINI-FOKA

    2012-12-01

    Full Text Available The first record for the Mediterranean Sea of the Red Sea/Indo-Pacific portunid Gonioinfradens paucidentatus (red swimming crab is documented. A detailed description of the specimens collected at Rodos Island (southeastern Aegean Sea is given, while possible introduction vectors of the species in the area are discussed.

  10. Gonioinfradens paucidentatus (A. Milne Edwards, 1861 (Crustacea, Decapoda, Portunidae: a new alien crab in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    M. CORSINI-FOKA

    2010-11-01

    Full Text Available The first record for the Mediterranean Sea of the Red Sea/Indo-Pacific portunid Gonioinfradens paucidentatus (red swimming crab is documented. A detailed description of the specimens collected at Rodos Island (southeastern Aegean Sea is given, while possible introduction vectors of the species in the area are discussed.

  11. Family formation and dissolution in an Aegean island.

    Science.gov (United States)

    Gavalas, Vasilis S

    2005-05-01

    This paper explores family formation and dissolution in the Aegean island of Paros over the period 1894-1998. The examined issues are: trends in age at marriage, age gap between spouses, age differentials among different occupational groups, age at widowhood, remarriage, illegitimacy and bridal pregnancy. The main findings confirmed that certain characteristics of the 'Mediterranean' marriage pattern, such as low age at marriage for females, high for males and large age gap between spouses, were present in the study population up until the 1980s. The feature of the family cycle that has changed most dramatically over the examined period is age at widowhood, which has increased spectacularly owing to the impressive progress in adult, and especially maternal, mortality that took place in Greece in the post-war years.

  12. An integrated approach to teaching Aegean archaeology and archaeological science

    Science.gov (United States)

    Pitcairn, Erica Glenn

    Outlined here is a course that would serve as an introduction to archaeological science, specifically within the context of Aegean Prehistory. The main objective of this course is to expose students early in their archaeological careers to a variety of methods and questions, and to depart from the culture-historical perspective that typifies introductory survey courses. The class structure is equal parts lecture and discussion, moving between learning how the methods work and evaluating case studies. All graded assignments build on one another, guiding the students through designing their own research project. The ultimate goals of the assignments are to build key writing and professional skills, develop a basic understanding of research design, and to instill confidence that the student can contribute to the production of knowledge, whatever field he or she decides to pursue.

  13. The two-stage aegean extension, from localized to distributed, a result of slab rollback acceleration

    OpenAIRE

    Brun, Jean-Pierre; Faccenna, Claudio; Gueydan, Frédéric; Sokoutis, Dimitrios; Philippon, Mélody; Kydonakis, Konstantinos; Gorini, Christian

    2016-01-01

    International audience; Back-arc extension in the Aegean, which was driven by slab rollback since 45 Ma, is described here for the first time in two stages. From Middle Eocene to Middle Miocene, deformation was localized leading to i) the exhumation of high-pressure metamorphic rocks to crustal depths, ii) the exhumation of high-temperature metamorphic rocks in core complexes and iii) the deposition of sedimentary basins. Since Middle Miocene, extension distributed over the whole Aegean domai...

  14. Mean temperature of the catch (MTC in the Greek Seas based on landings and survey data

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    Athanassios C. Tsikliras

    2015-04-01

    Full Text Available The mean temperature of the catch (MTC, which is the average inferred temperature preference of the exploited species weighted by their annual catch, is an index that has been used for evaluating the effect of sea warming on marine ecosystems. In the present work, we examined the effect of sea surface temperature on the catch composition of the Greek Seas using the MTC applied on the official catch statistics (landings for the period 1970-2010 (Aegean and Ionian Seas and on experimental bottom trawl survey data for 1997-2014 (southern Aegean Sea. The MTC of the landings for the study period increased from 11.8 οC to 16.2 οC in the Aegean Sea and from 10.0 οC to 14.7 οC in the Ionian Sea. Overall, the rate of MTC increase was 1.01 οC per decade for the Aegean and 1.17 οC per decade for the Ionian Sea and was positively related to sea surface temperature anomalies in both areas. For the survey data, the increase of the MTC of the bottom trawl catch in the southern Aegean Sea was lower (0.51 οC per decade but referred to a shorter time frame and included only demersal species. The change in MTC of official and survey catches indicates that the relative catch proportions of species preferring warmer waters and those preferring colder waters have changed in favour of the former and that this change is linked to sea surface temperature increase, both internally (through the Atlantic Multidecadal Oscillation or externally (warming trend driven.

  15. Development of ramp-flat structures during Aegean extension

    Science.gov (United States)

    Brun, Jean-Pierre; Sokoutis, Dimitrios

    2014-05-01

    Low-angle extensional shear is frequently observed in the Aegean metamorphic rocks. This deformation is commonly interpreted as being related to detachment at crustal scale, yet it often corresponds to ramp-flat extensional systems that, at many places, control the deposition of Neogene sedimentary basins. From a mechanical point of view, the development of a ramp-flat structure requires the presence of weak layers that can be activated as décollement between stronger rocks units. In the Aegean, the décollement generally develops within the upper brittle crust (i.e. with temperatures lower than about 400°C) that consists in recently exhumed metamorphic rocks. The process by which, these layers become weak enough to form efficient décollements in extension is somewhat intriguing and not well understood. In this contribution we examine the particular case of ramp-flat structures of the Southern Rhodope Core Complex that controlled the deposition of late Miocene to Pleistocene sediments in continental and marine basins. Field evidence is used to argue that the décollement corresponds to marble layers that separate orthogneisses at 2-3 km depth within an upper brittle crust whose thickness is around 5 km. Field observation and stable isotope measurements suggest that the ramp-flat structure observed on the island of Thassos occurred in a marble unit rich in fluids at a temperature of around 200°C. Using laboratory experiments, we explore the geometry of extensional structures (fault systems, rollovers, piggy-back basins…) that can develop at crustal-scale as a function of: i) décollement depth and dip, ii) number of décollements, and iii) strength contrast, between the décollement and overlying strong units. The results are compared with the situation observed in the Southern Rhodope Core Complex. We are convinced that the principles of ramp-flat extension discussed here have a strong potential of application in many other orogenic domains affected by large

  16. HF Radar observations of the Dardanelles outflow current in North Eastern Aegean using validated WERA HF radar data

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    Z. KOKKINI

    2015-01-01

    Full Text Available A two-site WERA HF radar station was installed in November 2009 at the eastern coast of Lemnos Island in North Aegean Sea, aiming to monitor the surface inflow of Black Sea waters exiting from the Dardanelles Strait, as well as to constitute a coastal management tool for incidents of oil-pollution or save-and-rescue operations. Strong interference by foreign transmissions is a source of noise deteriorating the quality of the backscattered signal, thus significantly reducing the HF radar’s effective data return rate. In order to ameliorate this problem, further quality-control and data gap interpolating procedures have been developed and applied, to be used in addition to the procedures incorporated and used by the manufacturer’s signal processing software. The second-level processing involves traditional despiking in the temporal domain, preceding Empirical Orthogonal Function analysis. The latter is used not only to filter high-frequency noise but also to fill data gaps in time and space. The data reconstruction procedure has been assessed via comparison of (a HF radial with CODE-type drifter radial velocities as well as (b HF-derived virtual drifter tracks with actual drifter tracks. The main circulation features and their variability, as revealed by the reconstructed fields, are presented.

  17. HF Radar observations of the Dardanelles outflow current in North Eastern Aegean using validated WERA HF radar data

    Directory of Open Access Journals (Sweden)

    Z. KOKKINI

    2014-12-01

    Full Text Available A two-site WERA HF radar station was installed in November 2009 at the eastern coast of Lemnos Island in North Aegean Sea, aiming to monitor the surface inflow of Black Sea waters exiting from the Dardanelles Strait, as well as to constitute a coastal management tool for incidents of oil-pollution or save-and-rescue operations. Strong interference by foreign transmissions is a source of noise deteriorating the quality of the backscattered signal, thus significantly reducing the HF radar’s effective data return rate. In order to ameliorate this problem, further quality-control and data gap interpolating procedures have been developed and applied, to be used in addition to the procedures incorporated and used by the manufacturer’s signal processing software. The second-level processing involves traditional despiking in the temporal domain, preceding Empirical Orthogonal Function analysis. The latter is used not only to filter high-frequency noise but also to fill data gaps in time and space. The data reconstruction procedure has been assessed via comparison of (a HF radial with CODE-type drifter radial velocities as well as (b HF-derived virtual drifter tracks with actual drifter tracks. The main circulation features and their variability, as revealed by the reconstructed fields, are presented.

  18. Sphingophosphonolipids, phospholipids, and fatty acids from Aegean jellyfish Aurelia aurita.

    Science.gov (United States)

    Kariotoglou, D M; Mastronicolis, S K

    2001-11-01

    The goal of this study is to elucidate and identify several sphingophosphonolipids from Aurelia aurita, an abundant but harmless Aegean jellyfish, in which they have not previously been described. Total lipids of A. aurita were 0.031-0.036% of fresh tissue, and the lipid phosphorus content was 1.3-1.7% of total lipids. Phosphonolipids were 21.7% of phospholipids and consisted of a major ceramide aminoethylphosphonate (CAEP-I; 18.3%), as well as three minor CAEP (II, III, IV) methyl analogs at 1.3, 1.1, and 1.0%, respectively. The remaining phospholipid composition was: phosphatidylcholine, 44.5%, including 36.2% glycerylethers; phosphatidylethanolamine, 18.6%, including 4.5% glycerylethers; cardiolipin, 5.6%; phosphatidylinositol, 2.6%; and lysophosphatidylcholine, 5.0%. In CAEP-I, saturated fatty acids of 14-18 carbon chain length were 70.8% and were combined with 57.3% dihydroxy bases and 23.4% trihydroxy bases. The suite of the three minor CAEP methyl analogs were of the same lipid class based on the head group, but they separated into three different components because of their polarity as follows: CAEP-II and CAEP-III differentiation from the major CAEP-I was mainly due to the increased fatty acid unsaturation and not to a different long-chain base, but the CAEP-IV differentiation from CAEP-I, apart from fatty acid unsaturation, was due to the increased content of hydroxyl groups originated from both hydroxy fatty acids and trihydroxy long-chain bases. Saturated fatty acids were predominant in total (76.7%), polar (83.0%), and neutral lipids (67.6%) of A. aurita. The major phospholipid components of A. aurita were comparable to those previously found in a related organism (Pelagia noctiluca), which can injure humans.

  19. The economic determinants of Greek return migration to the islands of the East Aegean.

    Science.gov (United States)

    Robolis, S; Xideas, E

    1996-01-01

    "The purpose of this article is to investigate the economic determinants of Greek return migration to the islands of the East Aegean, a region comprising hundreds of islands of different size in four administrative departments....[It] examines the sensitivity of return migration flows to changes in economic variables which influence decisions to return....The purpose...is to investigate the effect on return migration not only of economic development in the host country (push factors) but also of economic development in the islands of the East Aegean (pull factors), given their isolation from the mainland and their different economic structures." (SUMMARY IN SPA AND FRE)

  20. On the Impacts of Different Surface Forcing Regimes for Deep Water Formation in the Mediterranean Sea

    Science.gov (United States)

    Josey, S.; Tsimplis, M.; Gomis, D.; Ruiz, S.; Marcos, M.; Somot, S.

    2009-04-01

    Deep water formation is known to occur at 3 major sites (the Gulf of Lions, Adriatic and Aegean Seas) in the Mediterranean basin. However, the role played by air-sea interaction in setting the frequency and strength of formation events (including major transient episodes such as that experienced in the Aegean sea in the early 1990s) is not well understood. We will explore this relationship using air-sea heat, freshwater and density flux fields, including output from downscaled versions (HIPOCAS and ARPERA) of the NCEP/NCAR and ECMWF reanalyses. The downscaled fields reveal small scale forcing features (including jet-like structures over the dense water formation sites) that are not present in the coarser resolution reanalysis datasets. They also show greater variability in the forcing of the Aegean and the Gulf of Lions than the Adriatic Sea. The differences between the forcing distributions of the Aegean and Adriatic will be discussed in detail and will be advanced as a potential cause for variations in frequency of dense water formation in these two regions.

  1. The interaction between Aegean back-arc extension and Anatolia escape since Middle Miocene

    NARCIS (Netherlands)

    Philippon, M.; Brun, J.-P.; Gueydan, F.; Sokoutis, D.

    2014-01-01

    The Aegean domain is a key area for understanding the processes of back-arc extension. Observed deformation pattern and present day kinematics result from the interaction between the southward retreat of the Hellenic trench and the westward escape of Anatolia. Lithosphere-scale analogue models were

  2. The ‘Mycenaeans’ in the south-eastern Aegean revisited

    NARCIS (Netherlands)

    J. Eerbeek

    2014-01-01

    The main subject of this dissertation is the Mycenaean archaeological evidence from the south-eastern Aegean. The term "Mycenaean" is typically used to refer to the dominant archaeological culture of the central and southern Greek mainland during the Late Bronze Age, which is dated between about 170

  3. The Alpine evolution of Thessaly (NW Greece) and Late Tertiary Aegean kinematics

    NARCIS (Netherlands)

    Walcott, C.R.

    1998-01-01

    The Aegean region is one ofthe most studied regions currently undergoing post-orogenic extension. Numerous kinematic and dynamic models have been proposed to account for its active tectonics. Most recent studies have demonstrated that, since the onset ofextension in the early Miocene, there has been

  4. Greening the Campus Intentions: A Study of the University of the Aegean Non-Academic Staff

    Science.gov (United States)

    Bellou, Chrysanthi; Petreniti, Vassiliki; Skanavis, Constantina

    2017-01-01

    Purpose: This study aims to focus on the University of Aegean's non-academic staff's environmental sustainability attitudes and behavior both at work and at home, their perceptions for sustainability enforcement and their active participation skills. Design/methodology/approach: The research participants were the 101 non-academic staff working at…

  5. Elevated heavy metal concentrations in top soils of an Aegean island town (Greece): total and available forms, origin and distribution.

    Science.gov (United States)

    Massas, I; Ehaliotis, C; Gerontidis, S; Sarris, E

    2009-04-01

    Elevated heavy metal concentrations in urban top soils are principal indicators of environmental pollution; however, relative data on the heavy metal status in soils of Greek island towns, that are regional administrative centers and popular tourist destinations, are missing. A survey was conducted to examine heavy metal concentrations in the urban soils of Ermoupolis, the capital of Syros island and of the prefecture of Cyclades complex in the Aegean Sea. Total (aqua-regia extracted) and available (DTPA extracted) concentrations of Cu, Pb, Zn, Ni, Cr, Sn and Fe were determined in top soil samples collected from green areas and open spaces of the town and in surface samples from inland reference soils of the island. Mean values for the aqua-regia extracted fraction of Cu, Pb and Zn were 117, 155 and 440 mg kg(-1) respectively, up to four times higher than the respective mean values of the reference soils. Enrichment factors (EFs) for these metals indicated high accumulation in the urban top soils and the available to total concentration ratio of Cu, Pb, Zn and Fe was higher for the urban compared to the reference soils, suggesting differences in metal sequestration, resulting in higher metal availability in the urban soils. GIS analysis was used to visualize the spatial distribution of EFs of the studied heavy metals. Factor Analysis and Cluster Analysis, applied to aqua-regia and DTPA data sets, adequately elucidated the origin of metals grouped under each factor or cluster.

  6. Modelling the state of the Mediterranean Sea under contemporary and future climate

    Science.gov (United States)

    Solidoro, Cosimo; Lazzari, Paolo; Cossarini, Gianpiero; Melaku Canu, Donata; Lovato, Tomas

    2016-04-01

    A validated 3D coupled transport-biogeochemical model is used to assess the impact of future climatic and management scenarios on biogeochemical and ecological properties of the Mediterranean Sea. Results are discussed in term of temporal and spatial distribution of parameters and indicators related to the carbonate system and the cycles of carbon and inorganic nutrients through dissolved and particulate phases, as simulated by a multi nutrient multi plankton numerical model under current and future conditions. Simulations span the period 1990-2040 and are performed by forcing a three-dimensional off-line coupled eco-hydrodynamical model (BFM and OPA-tracer model) with current fields produced by ad hoc implementation of the NEMO modelling system and with river input of nutrient and freshwater computed in recent European fp7 projects. The model properly describes available experimental information on contemporary seasonal dynamic and spatial distribution at the basin and sub-basin scale of major biogeochemical parameters, as well as primary production and carbon fluxes at the air-ocean interface. Model projections suggest that future Mediterranean sea will be globally warmer, more productive, and more acidic, but with significant space variability. Consequences in terms of ecological and higher trophic level organisms dynamics are discussed as well, also in reference with impact on space distribution of suitable site for aquaculture activity and future space distributions of suitability habitats for habitat building organisms (e.g. Poseidonia, Coralligenous)

  7. First occurrence of the Indo-Pacific polychaete species Glycinde bonhourei Gravier, 1904 in the Hellenic seas (Northern Evvoikos Gulf

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

    Full Text Available A specimen of Glycinde bonhourei Gravier, 1904, an Indo-Pacific species, was found at a station near the metalliferous waste disposal in the Northern Evvoikos Gulf (Aegean Sea, eastern Mediterranean. This is the second report of this species in the Mediterranean Sea after its first finding in the Levantine basin (Israel and Egypt. This paper provides new information on its distributional range in the Mediterranean Sea.

  8. North Aegean island landscapes as ecomuseums: the case of Lesvos Island

    Directory of Open Access Journals (Sweden)

    Evangelos Pavlis

    2017-05-01

    Full Text Available The main advantage of the Aegean islands, in generating national, regional, or international competitiveness, compared to the areas on the continental mainland, is their natural and cultural assets, their cultural landscapes. Consequently, the organized utilization of cultural heritage, rich biodiversity, and the unique Aegean landscape, could make the islands attractive as places to live or work and help them fulfill their sustainability goals. Ecomuseums are ‘in situ’ museums, aimed at local communities and managed by them, aiming at the interpretation, protection, utilization, and promotion of natural and cultural assets of a place, and at the economic revival of marginal regions through the combinational development of small-scale tourism, local manufacturing, and primary production sectors. They could function as laboratories of sustainable development. The island of Lesvos has been selected as a case study for such a potential ecomuseum.

  9. Reproductive potential of silver European eels (Anguilla anguilla migrating from Vistonis Lake (Northern Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    R. MACNAMARA

    2014-06-01

    Full Text Available The European eel (Anguilla anguilla, once abundant throughout much of Europe and North Africa, has recently been classified as critically endangered. Information on its biology from the eastern Mediterranean is lacking, especially in relation to spawner quality. Therefore, silver eels were sampled during their seaward spawning migration from Vistonis Lake in Greece. Characteristics linked to reproductive output and success (i.e. body size and condition, sex ratio, silvering, Anguillicola crassus infection, fecundity and oocyte diameter were examined. The lake produced large (687–1138 mm, exclusively female silver eels, 61.7% of which were infected by A. crassus. Silver eel fecundity, the first estimates from the southern part of the species range, was positively related to body length (R2 = 0.693; P < 0.001 and body weight (R2 = 0.731; P < 0.001. Fecundity did not differ between A. crassus infected and uninfected silver eels, but Greek silver eels were significantly more fecund than those in north-west Europe. The reproductive potential of Vistonis Lake silver eels and their contribution to the A. anguilla spawning stock is discussed.

  10. Numerical modelling of tsunami generated by the 1650 eruption of Kolumbo, South Aegean Sea, Greece

    Science.gov (United States)

    Ulvrova, M.; Paris, R.; Kelfoun, K.; Nomikou, P.

    2013-12-01

    Historical 1650 tsunami generated by explosion of Kolumbo volcano was investigated. Using nonlinear shallow water equations implemented in COMCOT tsunami modelling package we simulate for the tsunami generation and propagation, and compute the inundation distances inland along the nearby Santorini island. Two tsunamigenic mechanisms are tested. First, we assume a scenario of phreatomagmatic explosion. Eruption is investigated using a model for shallow underwater explosions. A systematic study is performed for explosion energy range between 1014 and 1017~J. Second, we employed a caldera collapse scenario with duration up to 2~h. The first waves hit the coast of Santorini, the most populated island in the area and also the closest one to Kolumbo ( ˜~7~km), in about 3~min. Calculated inundation distances with predicted nearshore waves amplitudes provide insights into possible tsunami impact and help to assess the tsunami hazard for this region.

  11. Large-scale bioprospecting of cyanobacteria, micro- and macroalgae from the Aegean Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Montalvao, S.; Demirel, Z.; PrabhaDevi; Lombardi, V.; Hongisto, V.; Perala, M.; Hattara, J.; Imamoglu, E.; Tilvi, S.; Turan, G.; Dalay, M.C.; Tammela, P.

    . The cells were fed by completely replacing the media once per week. Primary astrocyte cell culture preparation and feeding Two-day old Wistar neonatal rat pups were sacrificed in a CO2 chamber. Using micro-dissecting scissors, the skin was opened... at the midline of the head, cutting from the base of the skull to the mid- eye area. After folding back the skin flaps with the scissors, the skull was cut at the midline fissure, without cutting into the brain tissue. The raised skullcap was removed...

  12. Causes of long-term changes in Aegean sea deep water

    OpenAIRE

    Boscolo, R; Bryden, H.

    2001-01-01

    Des observations récentes de l’eau profonde nouvellement formée en mer Égée permettent de déterminer si son origine est locale, suite à l’action combinée de l’évaporation nette et de la transformation hivernale de la masse d’eau. Les détournements des cours de rivières en Russie et en Égypte depuis les années cinquante ont en effet accru l’évaporation nette dans le bassin oriental de la Méditerranée. Des profils historiques montrent que les eaux intermédiaires de basse salinité séparent les m...

  13. Illegal immigration in the eastern Aegean Sea: a new source of marine litter

    National Research Council Canada - National Science Library

    KATSANEVAKIS, S

    2015-01-01

    .... This novel type of marine litter dominates many beaches and becomes increasingly abundant. Two beaches in Lesvos Island were surveyed for marine litter, and immigration-related items were found to account for more than 97...

  14. Climatological Factors Affecting Electromagnetic Surface Ducting in the Aegean Sea Region

    Science.gov (United States)

    2012-03-01

    19  x Figure 11.  The Azores or Bermuda High and southwest and south-central Asia thermal low tend to produce a...of Frequency (green lines with triangle markers), moisture mixing ratio at the surface level (blue lines with rhombus markers) and moisture mixing...of Frequency (green lines with triangle markers), moisture mixing ratio at the surface level (blue lines with rhombus markers) and moisture mixing

  15. Westward advancement of Pseudonereis anomala (Polychaeta: Nereididae in the Mediterranean Basin (Piraeus, Saronikos Bay, Aegean Sea

    Directory of Open Access Journals (Sweden)

    V. KAMBOUROGLOU

    2006-06-01

    Full Text Available This paper reports the establishment of the Lessepsian Pseudonereis anomala (Gravier, 1901 in its new locality in the port of Piraeus (Saronikos Bay and provides additional information on its population. The mean densities of P. anomala ranged from 0 indiv./m2 to 382.5 indiv./m2 among the calcareous alga Corallina elongata. A variety of sizes (length of the head and fi rst ten chaetigerous segments was observed ranging fromPseudonereis anomala; Saronikos Gulf; Polychaete; Immigrant. 1.3mm to 8.1mm. There are indications that P. anomala may compete with other species of Nereididae. Accepted in December 2006

  16. Feeding and ecomorphology of three clupeoids in the N Aegean Sea

    Directory of Open Access Journals (Sweden)

    P. K. KARACHLE

    2013-12-01

    Full Text Available The present study examines the feeding habits of anchovy (Engraulis encrasicolus, sardine (Sardina pilchardus and round sardinella (Sardinella aurita. The results are combined with previously published information on feeding-related morphological features (i.e. mouth area, intestine length and tail area in order to explore morphological affinities between species and the effect of ecomorphology on their co-existence. These species were mainly zooplanktivorous and no dietary differences were found with sex and season. Anchovy preyed mainly on Crustacea larvae, whereas sardine and round sardinella on Copepoda. In the majority of cases (>90%, the individual fractional trophic level of all species ranged between 3.0 and 3.5, classifying them as omnivores with preference to animals. The feeding-related morphological features differed between anchovy and the two other species, whereas only intestine length differed between sardine and round sardinella. The fact that round sardinella’s diet and morphology show a greater resemblance to those of sardine, further support the hypothesis that is a particulate feeder as sardine. Hence the three species tend to exploit the same food resources differently throughout the year. Thus, they make best use of the environment and its resources, in order to avoid competition and achieve optimum feeding conditions throughout their life cycles

  17. Network-Based Mitigation of Illegal Immigration in Aegean Sea (Greece)

    Science.gov (United States)

    2010-09-01

    and also taking into account the equidistant territorial middle line in the channel, the reaction time is limited for HCG crews (Figure 21). 42...The distances among the nodes are as follows:  SN1- SN2 :15km SN2 -SN3: 35km SN3-SN4: 11km 44 Figure 23. Lesvos model network surveillance...20󈧽, E26°15󈧪– Elev.697m)  RN2 : Akrotiri (N39° 04󈧺. E 26°33󈧒– Elev.258m)  RN1-SN1: 7km RN1- SN2 : 10km  RN1-SN3: 37km RN1-SN4: 47km

  18. Benthic microbial abundance and activities in an intensively trawled ecosystem (Thermaikos Gulf, Aegean Sea)

    Science.gov (United States)

    Polymenakou, Paraskevi N.; Pusceddu, Antonio; Tselepides, Anastasios; Polychronaki, Thalia; Giannakourou, Antonia; Fiordelmondo, Carla; Hatziyanni, Eleni; Danovaro, Roberto

    2005-12-01

    Abundance of benthic bacteria, heterotrophic nanoflagellates and ciliates, extracellular enzymatic activities, bacterial C production, C mineralisation and sediment community oxygen consumption rates were measured in the Thermaikos Gulf (Northeastern Mediterranean), before (September 2001), and during intense trawling activities (October 2001 and February 2002). The biochemical composition of sedimentary organic matter has revealed that bottom trawling had an effect on the trophic state of Thermaikos Gulf. Changes on the benthic microbial food web were also recorded, during the three sampling seasons. Even though trawling-induced sediment resuspension did not alter significantly the abundance of the microbial components, with the exception of the most impacted station, it determined changes regarding their relative importance. Thus, the ratios of bacterium to nanoflagellates and ciliate to nanoflagellates abundance increased in the trawled stations, causing a sudden increase in bacterial C production, in comparison to the non-trawled station. Four months later, the effects of trawling on the microbial food web were less evident, masked possibly by the drastic decrease in the water temperature. The results of the present work suggest that bottom trawling induces alteration of the sedimentological variables and can be considered as a factor affecting the function of the microbial food web in marine coastal ecosystems. These alterations cause faster mobilisation of organic C buried in the sediment and increase nutrient concentrations and availability in the system, thus inducing an effect that could lead to coastal eutrophication.

  19. A three-step model to assess shoreline and offshore susceptibility to oil spills: the South Aegean (Crete) as an analogue for confined marine basins.

    Science.gov (United States)

    Alves, Tiago M; Kokinou, Eleni; Zodiatis, George

    2014-09-15

    This study combines bathymetric, geomorphological, geological data and oil spill predictions to model the impact of oil spills in two accident scenarios from offshore Crete, Eastern Mediterranean. The aim is to present a new three-step method of use by emergency teams and local authorities in the assessment of shoreline and offshore susceptibility to oil spills. The three-step method comprises: (1) real-time analyses of bathymetric, geomorphological, geological and oceanographic data; (2) oil dispersion simulations under known wind and sea current conditions; and (3) the compilation of final hazard maps based on information from (1) and (2) and on shoreline susceptibility data. The results in this paper show that zones of high to very-high susceptibility around the island of Crete are related to: (a) offshore bathymetric features, including the presence of offshore scarps and seamounts; (b) shoreline geology, and (c) the presence near the shore of sedimentary basins filled with unconsolidated deposits of high permeability. Oil spills, under particular weather and oceanographic conditions, may quickly spread and reach the shoreline 5-96 h after the initial accident. As a corollary of this work, we present the South Aegean region around Crete as a valid case-study for confined marine basins, narrow seaways, or interior seas around island groups.

  20. New Fisheries-related data from the Mediterranean Sea (April 2014

    Directory of Open Access Journals (Sweden)

    K. STERGIOU

    2013-12-01

    Full Text Available As part of its policy, Mediterranean Marine Science started from 2014 to publish a new series of collective article with fisheries-related data from the Mediterranean Sea. In this first collective article we present length frequencies and weight-length relationships for the northern brown shrimp Farfantepenaeus aztecus in the eastern Mediterranean, length-weight relationships for 10 fish species in the North Aegean Sea, the feeding habits for 11 sparid fishes in the North Aegean Sea, a review of the existing literature on the feeding and reproduction of common carp Cyprinus carpio in Anatolia (Turkey and mouth dimensions and the relationships between mouth area and length for seven freshwater fishes from Lake Volvi (Northern Greece.

  1. Zircon crystallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean arc)

    Science.gov (United States)

    Bachman, O.; Charlier, B.L.A.; Lowenstern, J. B.

    2007-01-01

    In contrast to most large-volume silicic magmas in continental arcs, which are thought to evolve as open systems with significant assimilation of preexisting crust, the Kos Plateau Tuff magma formed dominantly by crystal fractionation of mafic parents. Deposits from this ~60 km3 pyroclastic eruption (the largest known in the Aegean arc) lack xenocrystic zircons [secondary ion mass spectrometry (SIMS) U-Pb ages on zircon cores never older than 500 ka] and display Sr-Nd whole-rock isotopic ratios within the range of European mantle in an area with exposed Paleozoic and Tertiary continental crust; this evidence implies a nearly closed-system chemical differentiation. Consequently, the age range provided by zircon SIMS U-Th-Pb dating is a reliable indicator of the duration of assembly and longevity of the silicic magma body above its solidus. The age distribution from 160 ka (age of eruption by sanidine 40Ar/39Ar dating; Smith et al., 1996) to ca. 500 ka combined with textural characteristics (high crystal content, corrosion of most anhydrous phenocrysts, but stability of hydrous phases) suggest (1) a protracted residence in the crust as a crystal mush and (2) rejuvenation (reduced crystallization and even partial resorption of minerals) prior to eruption probably induced by new influx of heat (and volatiles). This extended evolution chemically isolated from the surrounding crust is a likely consequence of the regional geodynamics because the thinned Aegean microplate acts as a refractory container for magmas in the dying Aegean subduction zone (continent-continent subduction).

  2. Zircon crytallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean arc)

    Science.gov (United States)

    Bachman, O.; Charlier, B.L.A.; Lowenstern, J. B.

    2007-01-01

    In contrast to most large-volume silicic magmas in continental arcs, which are thought to evolve as open systems with significant assimilation of preexisting crust, the Kos Plateau Miff magma formed dominantly by crystal fractionation of mafic parents. Deposits from this ??? 60 km3 pyroclastic eruption (the largest known in the Aegean arc) lack xenocrystic zircons [secondary ion mass spectrometry (SIMS) U-Pb ages on zircon cores never older than 500 ka] and display Sr-Nd whole-rock isotopic ratios within the range of European mantle in an area with exposed Paleozoic and Tertiary continental crust; this evidence implies a nearly closed-system chemical differentiation. Consequently, the age range provided by zircon SIMS U-Th-Pb dating is a reliable indicator of the duration of assembly and longevity of the silicic magma body above its solidus. The age distribution from 160 ka (age of eruption by sanidine 40Ar/39Ar dating; Smith et al., 1996) to ca. 500 ka combined with textural characteristics (high crystal content, corrosion of most anhydrous phenocrysts, but stability of hydrous phases) suggest (1) a protracted residence in the crust as a crystal mush and (2) rejuvenation (reduced crystallization and even partial resorption of minerals) prior to eruption probably induced by new influx of heat (and volatiles). This extended evolution chemically isolated from the surrounding crust is a likely consequence of the regional geodynamics because the thinned Aegean microplate acts as a refractory container for magmas in the dying Aegean subduction zone (continent-continent subduction). ?? 2007 Geological Society of America.

  3. Carbon fluxes from hydrothermal vents off Milos, Aegean Volcanic Arc, and the influence of venting on the surrounding ecosystem.

    Science.gov (United States)

    Dando, Paul; Aliani, Stefano; Bianchi, Nike; Kennedy, Hilary; Linke, Peter; Morri, Carla

    2014-05-01

    The island of Milos, in the Aegean Sea, has extensive hydrothermal fields to the east and southeast of the island with additional venting areas near the entrance to and within the central caldera. A calculation of the total area of the vent fields, based on ship and aerial surveys, suggested that the hydrothermal fields occupy 70 km2, twice the area previously estimated. The vents ranged in water depth from the intertidal to 300 m. As a result of the low depths there was abundant free gas release: in places water boiled on the seabed. The stream of gas bubbles rising through the sandy seabed drove a shallow re-circulation of bottom seawater. The majority of the water released with the gas, with a mean pH of 5.5, was re-circulated bottom water that had become acidified in contact with CO2 gas and was often diluted by admixture with the vapour phase from the deeper fluids. The major component of the free gas, 80%, was CO2, with an estimated total flux of 1.5-7.5 x 1012 g a-1. The methane flux, by comparison, was of the order of 1010 g a.-1 Using methane as a tracer it was shown that the major gas export from the vents was below the thermocline towards the southwest, in agreement with the prevailing currents. Areas of hydrothermal brine seepage occurred between the gas vents and occasional brine pools were observed in seabed depressions. Under relatively calm conditions, many of the brine seeps were covered by thick minero-bacterial mats consisting of silica and sulphur and surrounded by mats of diatoms and cyanobacteria. The minerals were not deposited in the absence of bacteria. Storms disrupted the mats, leading to an export of material to the surrounding area. Stable isotope data from sediments and sediment trap material suggested that exported POM was processed by zooplankton. The combined effects of the geothermal heating of the seabed, the large gas flux, variation in the venting and the effect of the brine seeps had a dramatic effect on the surrounding

  4. PREFACE: Donald D Harrington Symposium on the Geology of the Aegean

    Science.gov (United States)

    Catlos, Elizabeth J.

    2008-03-01

    This volume of the IOP Conference Series: Earth and Environmental Sciences presents a selection of papers given at the Donald D Harrington Symposium on the Geology of the Aegean held on the campus of the University of Texas at Austin on April 28-30, 2008. Donald D Harrington was born in Illinois in 1899 and moved westward after serving in the Army Air Corps during World War I. Mr Harrington took a position as a landman with Marlin Oil Company in Oklahoma. When the Texas Panhandle oil boom hit in 1926, he moved to Amarillo, Texas, where he met Sybil Buckingham—the granddaughter of one of Amarillo's founding families. They married in 1935 and went on to build one of the most successful independent oil and gas operations in Texas history. The couple created the Don and Sybil Harrington Foundation in 1951 to support worthy causes such as museums, medical research, education, and the arts. At the Harrington Symposium on the Geology of the Aegean, researchers presented papers organized under five general themes: (1) the geology of Aegean in general (2) the geologic history of specific domains within the Aegean (Cyclades, Menderes, Kazdag, Rhodope, Crete, southern Balkans, etc) (3) the dynamic tectonic processes that occur within the Aegean (4) its geo-archeological history, natural history and hazards and (5) comparisons of the Aegean to regions elsewhere (e.g., Basin and Ranges; Asian extensional terranes). The Aegean is a locus of dynamic research in a variety of fields, and the symposium provided an opportunity for geologists from a range of disciplines to interact and share new results and information about their research in the area. At the opening reception in the Harry S Ransom Center, Dr Clark Burchfiel (Massachusetts Institute of Technology, USA) provided a keynote address on the outstanding geologic problems of the Aegean region. His paper in this volume outlines a framework for future studies. We also call attention to a paper in this volume by Dr Y

  5. Bidirectional air–sea exchange and accumulation of POPs (PAHs, PCBs, OCPs and PBDEs) in the nocturnal marine boundary layer

    OpenAIRE

    Lammel, Gerhard; Meixner,Franz X.; Vrana, Branislav; Efstathiou, Christos I.; Kohoutek, Jiři; Kukučka, Petr; Mulder, Marie D.; Přibylová, Petra; Prokeš, Roman; Rusina, Tatsiana P.; Song, Guo-Zheng; Tsapakis, Manolis

    2016-01-01

    As a consequence of long-range transported pollution, air–sea exchange can become a major source of persistent organic pollutants in remote marine environments. The vertical gradients in the air were quantified for 14 species, i.e. four parent polycyclic aromatic hydrocarbons (PAHs), three polychlorinated biphenyls (PCBs), three organochlorine pesticides (OCPs) and two polybrominated diphenylethers (PBDEs) in the gas-phase at a remote coastal site in the southern Aegean Sea ...

  6. Spatial distribution of vector borne disease agents in dogs in Aegean region, Turkey

    Directory of Open Access Journals (Sweden)

    Kerem Ural

    2014-06-01

    Full Text Available Objective. Assess the spatial distribution of seroprevalence of infection with or exposure to 4 vector-borne pathogens Ehrlichia canis, Anaplasma phagocytophilum, Borrelia burgdorferi and Dirofilaria immitis, across the coastal states of the Aegean region with special reference to clinical signs and haematological variances related to disease condition. Materials and methods. A convenience sample, targeting blood from at least 10 pet dogs from İzmir, Aydin, Denizli, Mugla and Manisa cities involved was evaluated using a canine point-of-care ELISA kit. Results. Out of 307 dogs tested the overall seroprevalence was highest for E. canis (24.42%, followed by E. canis + A. phagocytophilum co-infection (10.42%, A. phagocytophilum (7.49% and D. immitis (2.28%. Only 2 cases were seropositive to B. burgdorferi albeit 10 dogs were co-infected with more than 2 agents. For both dogs infected with E. canis and co-infected with E. canis and A. phagocytophilum, anemia, thrombocytopenia and leukocytosis, were more commonly detected, whereas thrombocytopenia and leukocytosis were significant finding in dogs infected with A. phagocytophilum or D. immitis, respectively. Variance analysis showed significant differences for mean RBC, Hb, PCV and PLT values (p<0.01 among control group and other groups. Conclusions. Seropositivity for vector-borne pathogens other than B. burgdorferi, is moderately to widely distributed in dogs residing in the Aegean region in Turkey.

  7. Maximum Rain-Rate Evaluations in Aegean Archipelagos Hellas for Rain Attenuation Modeling at Microwave Frequencies

    Directory of Open Access Journals (Sweden)

    Evangelia Karagianni

    2016-04-01

    Full Text Available By utilizing meteorological data such as relative humidity, temperature, pressure, rain rate and precipitation duration at eight (8 stations in Aegean Archipelagos from six recent years (2007 – 2012, the effect of the weather on Electromagnetic wave propagation is studied. The EM wave propagation characteristics depend on atmospheric refractivity and consequently on Rain-Rate which vary in time and space randomly. Therefore the statistics of radio refractivity, Rain-Rate and related propagation effects are of main interest. This work investigates the maximum value of rain rate in monthly rainfall records, for a 5 min interval comparing it with different values of integration time as well as different percentages of time. The main goal is to determine the attenuation level for microwave links based on local rainfall data for various sites in Greece (L-zone, namely Aegean Archipelagos, with a view on improved accuracy as compared with more generic zone data available. A measurement of rain attenuation for a link in the S-band has been carried out and the data compared with prediction based on the standard ITU-R method.

  8. Preceramic, Aceramic or Early Ceramic? The radiocarbon dated beginning of the Neolithic in the Aegean

    Directory of Open Access Journals (Sweden)

    Agathe Reingruber

    2015-12-01

    Full Text Available The Pre-Pottery-Neolithic refers to a period in the Eastern Mediterranean when ceramic containers were not yet in use (although small objects made of clay were already being created. This concept, which reflects a specific and quite unique stage in the development of human history, was introduced to Aegean prehistory under the term of Preceramic during the 1950’s (e.g., in Argissa Magoula and Sesklo. Shortly thereafter, a different term, the Aceramic, was applied in the Aegean (e.g., in Knossos for levels devoid of pottery, although ceramic products were supposedly used in the wider region. In some cases, the thin levels interpreted as Preceramic or as Aceramic contained sherds that were regarded as being intrusive from above (e.g., Argissa-Magoula, Franchthi Cave. The new sequences of radiocarbon dates allow a more precise description of this early period and thereby contribute, not least, also to the clarification of terminological issues.

  9. Non-extensive statistical physics analysis of earthquake magnitude sequences in North Aegean Trough, Greece

    Science.gov (United States)

    Papadakis, Giorgos; Vallianatos, Filippos

    2017-06-01

    In a recent study, Papadakis et al. (Physica A 456: 135-144, 2016) investigate seismicity in Greece, using the non-extensive statistical physics formalism. Moreover, these authors examine the spatial distribution of the non-extensive parameter q M and show that for shallow seismicity, increase of q M coincides with strong events. However, their study also reveals low q M values along the North Aegean Trough, despite the presence of strong events during 1976-2009. Consequently, the present study further examines the temporal behaviour of parameters q M and A, to reveal their relation with the evolution of the earthquake sequence. Through temporal examination of these parameters, we aim to show that the seismogenic system of the North Aegean Trough presents high degree of interactions after strong earthquakes during the studied period. Our findings indicate that increase of q M signifies the existence of long-range correlations. If its value does not significantly decrease after a strong earthquake (i.e. M ≥ 5) then the studied area has not reached the state of equilibrium.

  10. Connecting export fluxes to plankton food web efficiency in the Black Sea waters inflowing into the Mediterranean Sea

    OpenAIRE

    2010-01-01

    Abstract The short-time scale evolution of plankton carbon partitioning and downward flux of the modified Black Sea Water (BSW) mass entering the northeast Aegean Sea was studied using a Lagrangian approach (6-10/04/2008). The free-drifting sediment trap positioned at the bottom of the BSW layer and the control drifter, followed the same path within the anticyclone that circulates the BSW in the area. ?ooplankton biomass increased (from 159 to 292 mg C m-2), as did faecal pellet pr...

  11. Periodicities in sediment temperature time-series at a marine shallow water hydrothermal vent in Milos Island (Aegean Volcanic arc, Eastern Mediterranean)

    Science.gov (United States)

    Aliani, Stefano; Meloni, Roberto; Dando, Paul R.

    2004-05-01

    Time-series data sets of total bottom pressure (tidal plus atmospheric), seawater temperature and sediment temperature from a marine shallow hydrothermal vent (Milos, Hellenic Volcanic Arc, Aegean Sea) were studied to determine factors influencing periodicity at the vents. Bottom pressure and vent temperature were mainly opposite in phase, with the main fluctuations of vent temperature occurring at tidal frequencies. Although the fluctuations in atmospheric pressure were of the same order as those due to tidal pressure, the contribution of atmospheric pressure was considerably weaker at diurnal frequencies. Some sudden discontinuities in sediment temperature were recorded, at least one of these may have been caused by seismic events. Seawater temperature changes were not reflected in the sediment temperature record. Transient loadings, such as tidal loadings, barometric pressure and earth tides, may affect the pore pressure in sediments, influencing fluid expulsion and sediment temperature as a consequence. Most of the contribution to the fluctuations in sediment temperature depends on tidal loadings. Gravitational forces, in the form of earth tides, can also be involved and barometric pressure is probably responsible for long period temperature oscillations.

  12. The Absolute Dating Potential of Proximal-Distal Tephra Correlations in an Aegean Marine Stratigraphy (Core LC21).

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    Satow, Christopher; Lowe, John; Rohling, Eelco; Blockley, Simon; Menzies, Martin; Grant, Katharine; Smith, Vicki; Tomlinson, Emma

    2010-05-01

    Quaternary marine stratigraphies frequently suffer from poor absolute age control. Radiocarbon dating is intuitively the most appropriate technique for most marine stratigraphies, but its application is limited to the last 50ka or so by the decay rate of carbon. There are also uncertainties related to reservoir effects and the calibration of radiocarbon time to real time. However, precise dating and correlation of marine cores is essential to understand the timing and spatial relationships of the valuable environmental records they preserve. Here we demonstrate the potential of both visible and "invisible" micro-tephra layers to precisely date an important marine environmental record (Core LC21 from the Southern Aegean Sea). This is done by geochemically correlating the distal marine tephra layers to proximal volcanic deposits from Italy, Greece and Turkey. We use both Major Element (EPMA- Oxford Archaeology) and Trace Element (LA-ICP-MS, Royal Holloway Earth Sciences) analyses on individual tephra shards to determine the source of the tephra, and to make the correlations to explosive eruptive events. The most precise date (14C, 39Ar:40Ar or U-Th) from the event's proximal deposit is then imported into the equivalent distal tephra found in the marine core. Many of these distal "micro-tephras" were previously undetected by standard core logging techniques such as visual stratigraphy or scanning XRF. The extent and potential application of these tephras is now being realised. This study will provide the first direct (same core) and independent, absolute chronological markers for sapropels S3, S4 and S5, three major anoxic events found in the Eastern Mediterranean. In addition, the major and trace element geochemistry will be used to robustly correlate three marine cores spanning the Mediterranean. This work forms the Marine Tephrostratigraphy component (Work Package 5) of the UK Natural Environment Research Council (NERC) consortium project "RESET" (Response of

  13. An Aegean island earthquake protection strategy: an integrated analysis and policy methodology.

    Science.gov (United States)

    Delladetsima, Pavlos Marinos; Dandoulaki, Miranda; Soulakellis, Nikos

    2006-12-01

    Viewing an insular setting as a distinct risk environment, an effort is made here to develop a methodology for identifying core issues related to earthquake risk and disaster protection policy, adjusted to the 'specificities' of such a context. The methodology's point of departure is the inherent condition of the 'island operating as a closed system', requiring an attempt to assess and optimise local capacity (social, political, economic, institutional and technical) to deal with an earthquake emergency. The island is then treated as an 'open system', implying that in the event of a disaster, it should be able to maximise its ability to receive and distribute external aid and to manage effectively population evacuation and inflows/outflows of aid resources. Hence, an appropriate strategic policy approach could be developed by integrating the 'open' and 'closed' system components of an island setting. Three islands from the Aegean Archipelagos in Greece--Chios, Kos and Nissyros--serve as case study areas.

  14. 3D instantaneous dynamics modeling of present-day Aegean subduction

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    Glerum, Anne; Spakman, Wim; van Hinsbergen, Douwe; Pranger, Casper

    2017-04-01

    To study the sensitivity of surface observables to subduction and mantle flow, i.e. the coupling of crustal tectonics and the underlying mantle dynamics, we have developed 3D numerical models of the instantaneous crust-mantle dynamics of the eastern Mediterranean. These models comprise both a realistic crust-lithosphere system and the underlying mantle. The focus for this presentation lies on the regional crustal flow response to the present-day Aegean subduction system. Our curved model domain measures 40°x40°x2900km with the Aegean subduction system taken as the geographic center. Model set-ups are based on geological and geophysical data of the eastern Mediterranean. We first create a 3D synthetic geometry of the crust-lithosphere system in a stand-alone program, including the present-day configuration of the plates in the region and crust and lithosphere thickness variations abstracted from Moho and LAB maps (Faccenna et al., 2014, Carafa et al., 2015). In addition we construct the geometry of the Aegean slab from a seismic tomography model (UU-P07; Amaru, 2007) and earthquake hypocenters (NCEDC, 2014). Geometries are then imported into the finite element code ASPECT (Kronbichler et al., 2012) using specially designed plugins. The mantle initial temperature conditions can include deviations from an adiabatic profile obtained from conversion of the UU-P07 seismic velocity anomalies to temperature anomalies using a depth-dependent scaling (Karato, 2008). We model compressible mantle flow for which material properties are obtained from thermodynamics P-T lookup-tables (Perple_X, Connolly, 2009) in combination with nonlinear viscoplastic rheology laws. Sublithospheric flow through the lateral model boundaries is left free via open boundary conditions (Chertova et al., 2012), while plate motion is prescribed at the model sides in terms of relative as well as absolute plate motion velocities (e.g. Doubrovine et al., 2012). So far, we used a free-slip surface, but

  15. Estimation of relative humidity based on artificial neural network approach in the Aegean Region of Turkey

    Science.gov (United States)

    Yasar, Abdulkadir; Simsek, Erdoğan; Bilgili, Mehmet; Yucel, Ahmet; Ilhan, Ilhami

    2012-01-01

    The aim of this study is to estimate the monthly mean relative humidity (MRH) values in the Aegean Region of Turkey with the help of the topographical and meteorological parameters based on artificial neural network (ANN) approach. The monthly MRH values were calculated from the measurement in the meteorological observing stations established in Izmir, Mugla, Aydin, Denizli, Usak, Manisa, Kutahya and Afyonkarahisar provinces between 2000 and 2006. Latitude, longitude, altitude, precipitation and months of the year were used in the input layer of the ANN network, while the MRH was used in output layer of the network. The ANN model was developed using MATLAB software, and then actual values were compared with those obtained by ANN and multi-linear regression methods. It seemed that the obtained values were in the acceptable error limits. It is concluded that the determination of relative humidity values is possible at any target point of the region where the measurement cannot be performed.

  16. Model estimating the effect of marginal ice zone processes on the phytoplankton primary production and air-sea flux of CO2 in the Barents Sea

    Science.gov (United States)

    Dvornikov, Anton; Sein, Dmitry; Ryabchenko, Vladimir; Gorchakov, Victor; Martjyanov, Stanislav

    2016-04-01

    This study is aimed to assess the impact of sea ice on the primary production of phytoplankton (PPP) and air-sea CO2 flux in the Barents Sea. To get the estimations, we apply a three-dimensional eco-hydrodynamic model based on the Princeton Ocean Model which includes: 1) a module of sea ice with 7 categories, and 2) the 11-component module of marine pelagic ecosystem developed in the St. Petersburg Branch, Institute of Oceanology. The model is driven by atmospheric forcing, prescribed from the reanalysis NCEP / NCAR, and conditions on the open sea boundary, prescribed from the regional model of the atmosphere-ocean-sea ice-ocean biogeochemistry, developed at Max Planck Institute for Meteorology, Hamburg. Comparison of the model results for the period 1998-2007 with satellite data showed that the model reproduces the main features of the evolution of the sea surface temperature, seasonal changes in the ice extent, surface chlorophyll "a" concentration and PPP in the Barents Sea. Model estimates of the annual PPP for whole sea, APPmod, appeared in 1.5-2.3 times more than similar estimates, APPdata, from satellite data. The main reasons for this discrepancy are: 1) APPdata refers to the open water, while APPmod, to the whole sea area (under the pack ice and marginal ice zone (MIZ) was produced 16 - 38% of PPP); and 2) values of APPdata are underestimated because of the subsurface chlorophyll maximum. During the period 1998-2007, the modelled maximal (in the seasonal cycle) sea ice area has decreased by 15%. This reduction was accompanied by an increase in annual PPP of the sea at 54 and 63%, based, respectively, on satellite data and the model for the open water. According to model calculations for the whole sea area, the increase is only 19%. Using a simple 7-component model of oceanic carbon cycle incorporated into the above hydrodynamic model, the CO2 exchange between the atmosphere and sea has been estimated in different conditions. In the absence of biological

  17. Predicting the composition of polychaete assemblages in the Aegean coast of Turkey

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    Marika Galanidi

    2016-08-01

    Full Text Available Benthic infaunal species and communities have been extensively used to evaluate quality of the marine environment. Within the MSFD, community composition is addressed most commonly through Descriptor 6 (Seafloor integrity, criterion 6.2 (Condition of benthic communities. At the same time, the Directive has stipulations for addressing and assessing indicators linked with pressures in an explicitly spatial manner. At larger scales, achieving this through point sampling may be impractical or unfeasible; hence predictive methods are being increasingly employed to produce the large scale spatial data that are often required for marine spatial planning and management.The aim of the current work was to develop statistical and spatial modelling tools that can predict the distribution of soft-sediment benthic polychaetes in the Aegean coast of Turkey. To do that, we employed Species Archetype Models (SAMs, a novel analytical and modelling framework which uses mixture models to cluster species responses to the environment, producing a number of archetypal responses assumed to represent species with similar ecological/physiological tolerances. Polychaete presence/absence data were obtained from the literature and modelling was performed against environmental variables reflecting the main natural and anthropogenic gradients in the region. The resulting models are interpreted in light of the sensitivity/tolerance classification scheme for benthic invertebrates.Three Species Archetypes were identified through the analysis. In brief, Species Archetype 1 consists of the most prevalent species in the dataset and primarily follows the salinity and temperature gradients. Species Archetype 2, present in the central and southern Aegean, is dominated by sensitive and indifferent species and responds negatively to chlorophyll a, whereas Species Archetype 3 represents mostly tolerant and opportunistic polychaetes with increased probability of occurrence in eutrophic

  18. Arc dacite genesis pathways: Evidence from mafic enclaves and their hosts in Aegean lavas

    Science.gov (United States)

    Zellmer, G. F.; Turner, S. P.

    2007-05-01

    Mafic enclaves are commonly found in intermediate arc magmas, and their occurrence has been linked to eruption triggering by pre-eruptive magma mixing processes. New major, trace, Sr-Nd and U-Th isotope data of rocks from Nisyros in the Aegean volcanic arc are presented here. Pre-caldera samples display major and trace element trends that are consistent with fractionation of magnetite and apatite within intermediate compositions, and zircon within felsic compositions, and preclude extensive hybridization between mafic and felsic magmas. In contrast, post-caldera dacites form a mixing trend towards their mafic enclaves. In terms of U-series isotopes, most samples show small 238U excesses of up to ˜ 10%. Mafic enclaves have significantly higher U/Th ratios than their dacitic host lavas, precluding simple models that relate the mafic and felsic magmas by fractionation or aging alone. A more complicated petrogenetic scenario is required. The post-caldera dacites are interpreted to represent material remobilized from a young igneous protolith following influx of fresh mafic magma, consistent with the U-Th data and with Sr-Nd isotope constraints that point to very limited (Santorini in the same arc, there are many geochemical similarities between the two volcanic centers during the petrogenesis of the pre-caldera samples. However, striking differences are apparent for the post-caldera lavas: in Nisyros, dacites show geochemical and textural evidence for magma mixing and remobilization by influx of mafic melts, and they erupt as viscous lava domes; in Santorini, evidence for geochemical hybridization of dacites and mafic enclaves is weak, dacite petrogenesis does not involve protolith remobilization, and lavas erupt as less viscous flows. Despite these differences, it appears that mafic enclaves in intermediate Aegean arc magmas consistently yield timescales of at least 100 kyrs between U enrichment of the mantle wedge and eruption, on the upper end of those estimated

  19. Neogene basin development around Söke-Kuşadası (western Anatolia) and its bearing on tectonic development of the Aegean region

    Science.gov (United States)

    Gürer, Ömer Feyzi; Bozcu, Mustafa; Yılmaz, Kamil; Yılmaz, Yücel

    There is a N-S lying narrow strip of Neogene outcrop between the towns of Kuşadası and Söke in western Anatolia. It contains remnants of successive Neogene graben basins. The first graben began to form under the control of a N40-70°E-trending oblique fault system during the Early Miocene. At the initial phase of the opening coarse clastic rocks were deposited in front of the fault-elevated blocks as scree deposits and fanglomerates. Later the graben advanced into a large lake basin. Towards the end of the Middle Miocene the lacustrine sediments of the Early-Middle Miocene age underwent an approximately N-S compressional deformation and elevated above the lake level, and were partly eroded. During the Late Miocene a new graben basin began to form as a consequence of the development of E-W-trending normal faults, formed under the N-S extensional regime. This graben also turned later into a lake environment. The lake extended far beyond the limits of the fault zones, and covered the entire regions stretching from the south of Bafa Lake in the south to Kuşadası and beyond in the north. Micritic clayey limestones were predominantly deposited in the lake. A severe erosional phase followed the termination of the lake basin. This corresponds to the cessation of the N-S extension. When the N-S extension regenerated during the Pliocene(?)-Pleistocene, the Büyük Menderes graben system began to form. In the western part of the graben, a conjugated pair of oblique faults, the Priene-Sazlı fault and the Kuşadası fault, have formed. The faults having important strike-slip components, bounded a tectonic wedge, which began to move westward into the Aegean Sea region. Major morphological features of the region were formed under the effective control of these fault zones.

  20. The record of magma chamber processes in plagioclase phenocrysts at Thera Volcano, Aegean Volcanic Arc, Greece

    Science.gov (United States)

    Stamatelopoulou-Seymour, Karen; Vlassopoulos, Dimitrios; Pearce, Thomas H.; Rice, Craig

    1990-01-01

    Lavas and pyroclastic rocks throughout the volcanic stratigraphy of the Tertiary-Quaternary volcanic complex of Thera in the Aegean island arc display inhomogenous plagioclase populations and phenocryst resorption textures, interpreted as indicative of magma mixing. Plagioclase zoning characteristics studied by Nomarski and laser interferometry techniques establish three main categories of plagioclase: (i) inherited plagioclase (nucleated in endmember prior to initial mixing event) (ii) in situ plagioclase (nucleated in mixed or hybrid magma) and (iii) xenocrystic plagioclase. Nomarski contrast images and linearized compositional zoning profiles reveal striking differences between calcic and sodic plagioclases, depending on the composition of the lava in which they are hosted. These differences reflect the contrasting effects of changes in physical-chemical parameters in basic vis-a-vis more acidic melts during magma mixing and/or influx of new magma into the subvolcanic magma chamber, as well as the influence of magma chamber dynamics on plagioclase equilibration. Variations in bulk major and trace element abundances of Thera volcanic products reflect the dominant overprint of crystal fractionation, but decoupling between major and trace element fractionation models and variations in incompatible trace element distributions are all indicative of magma mixing processes, consistent with compositional and textural zoning in plagioclases.

  1. Best fitting distributions for the standard duration annual maximum precipitations in the Aegean Region

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    Halil Karahan

    2013-03-01

    Full Text Available Knowing the properties like amount, duration, intensity, spatial and temporal variation etc… of precipitation which is the primary input of water resources is required for planning, design, construction and operation studies of various sectors like water resources, agriculture, urbanization, drainage, flood control and transportation. For executing the mentioned practices, reliable and realistic estimations based on existing observations should be made. The first step of making a reliable estimation is to test the reliability of existing observations. In this study, Kolmogorov-Smirnov, Anderson-Darling and Chi-Square goodness of distribution fit tests were applied for determining to which distribution the measured standard duration maximum precipitation values (in the years 1929-2005 fit in the meteorological stations operated by the Turkish State Meteorological Service (DMİ which are located in the city and town centers of Aegean Region. While all the observations fit to GEV distribution according to Anderson-Darling test, it was seen that short, mid-term and long duration precipitation observations generally fit to GEV, Gamma and Log-normal distribution according to Kolmogorov-Smirnov and Chi-square tests. To determine the parameters of the chosen probability distribution, maximum likelihood (LN2, LN3, EXP2, Gamma3, probability-weighted distribution (LP3,Gamma2, L-moments (GEV and least squares (Weibull2 methods were used according to different distributions.

  2. Evaluation of the therapeutic use of antibiotics in Aegean Region hospitals of Turkey: A multicentric study

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    O Ozgenç

    2011-01-01

    Full Text Available Purpose: The antibiotic restriction policy has been validated nationwide since February 2003 by the Ministry of Health because the excessive consumption of antimicrobials causes a high cost. The aim of this study was to evaluate the therapeutic use of antibiotics in Aegean Region hospitals and to assess the impact of this nationwide antibiotic restriction policy. This new policy is based on justification that the infectious disease (ID physicians should be primarily responsible for the prescription of antimicrobials. Materials and Methods: Eight university and government hospitals were included in the study. The criteria of the Council for Appropriate and Rational Antibiotic Therapy (CARAT were considered. Both patient-based and antibiotic-based analyses were performed. For the analysis of inappropriate use, logistic regression was modeled. Results: Therapeutic use was determined in 540 patients by a total of 29 ID physicians.In the study, 30.2% of the patients were given antimicrobials and empirically started antibiotics accounted for 79% cases of therapeutic antibiotic use, and 60% of those were inappropriate (P = 0.001. The appropriate use of ID level antibiotics (P = 0.000 were very compatible with other antimicrobial groups. Conclusion: The study shows that the Turkish government′s new intervention policy on antimicrobial prescribing has been effective.

  3. Creating the electric energy mix of a non-connected Aegean island

    Science.gov (United States)

    Stamou, Paraskevi; Karali, Sophia; Chalakatevaki, Maria; Daniil, Vasiliki; Tzouka, Katerina; Dimitriadis, Panayiotis; Iliopoulou, Theano; Papanicolaou, Panos; Koutsoyiannis, Demetris; Mamasis, Nikos

    2017-04-01

    As the electric energy in the non-connected islands is mainly produced by oil-fueled power plants, the unit cost is extremely high. Here the various energy sources are examined in order to create the appropriate electric energy mix for a non-connected Aegean island. All energy sources (renewable and fossil fuels) are examined and each one is evaluated using technical, environmental and economic criteria. Finally the most appropriate energy sources are simulated considering the corresponding energy works. Special emphasis is given to the use of biomass and the possibility of replacing (even partially) the existing oil-fueled power plant. Finally, a synthesis of various energy sources is presented that satisfies the electric energy demand taking into account the base and peak electric loads of the island. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  4. Pesticide residues in fruits and vegetables from the Aegean region, Turkey.

    Science.gov (United States)

    Bakırcı, Gözde Türköz; Yaman Acay, Dilek Bengü; Bakırcı, Fatih; Ötleş, Semih

    2014-10-01

    The purpose of this study was to investigate pesticide residues in fruits and vegetables from the Aegean region of Turkey. A total of 1423 samples of fresh fruit and vegetables were collected from 2010 to 2012. The samples were analysed to determine the concentrations of 186 pesticide residues. The analyses utilized ultrahigh performance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS/MS) and gas chromatography with an electron capture detector (GC-ECD) confirmed by gas chromatography with mass spectrometry (GC-MS) after a multi-residue extraction procedure (the QuEChERS method). The results were evaluated according to maximum residue limits (MRLs) for each commodity and pesticide by Turkish Regulation. All pomegranate, cauliflower and cabbage samples were pesticides-free. A total of 754 samples contained detectable residues at or below MRLs, and 48 (8.4%) of the fruit samples and 83 (9.8%) of the vegetable samples contained pesticide residues above MRLs. MRL values were most often exceeded in arugula, cucumber, lemon, and grape commodities. All detected pesticides in apricot, carrot, kiwifruit and leek were below the MRLs. Acetamiprid, chlorpyriphos and carbendazim were the most detected pesticide residues.

  5. Eltrombopag for the Treatment of Immune Thrombocytopenia: The Aegean Region of Turkey Experience

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    Füsun Özdemirkıran

    2015-12-01

    Full Text Available INTRODUCTION: OBJECTIVE: Immune thrombocytopenia (ITP is an immune mediated disease characterized by transient or persistent decrease of the platelet count to less than 100 × 109/l. Although it is included in a benign disease group, bleeding complications may be mortal. With a better understanding of the pathophysiology of the disease, thrombopoietin receptor agonists which came into use in recent years, seem to be an effective option in the treatment of resistant patients. METHODS: In this study, retrospective data of 40 patients who were treated with Eltrombopag due to the diagnosis of refractory ITP in the Aegean region were examined and evaluated. RESULTS: In the study total rate of response was 87%, and in the cases with response the median period that number of platelets reached over 50. × 109/l was determined as 19.5 (5-60 days. DISCUSSION AND CONCLUSION: CONCLUSION: In one patient venous sinus thrombosis was observed and showed no other additional risk factor due to/ related to thrombosis. The other patient with complete response and irregular follow-up for 12 months was lost due to sudden death as the result of propable acute myocardial infarction.

  6. Temperature and salinity variability in the Greek Seas based on POSEIDON stations time series: preliminary results

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    D. VELAORAS

    2013-07-01

    Full Text Available Temperature and salinity time series provided by three POSEIDON monitoring stations (buoys are examined in order to study the seasonal and interannual variability of the water mass characteristics. The sites at Athos (North Aegean Sea, E1M3A (Central Cretan Sea and Pylos (Eastern Ionian Sea were chosen, as these buoys provide measurements at various depths, while they represent 3 major basins respectively. The study of the T and S characteristics reveals important seasonal changes and highlights the particular characteristics of each basin. Dense water production in the Northern Aegean is found to be hindered by the presence of the surface Black Sea Water (BSW mass. On the other hand, the intermediate water mass in the Cretan Sea is shown to be ventilated during the winter season. A significant temperature and salinity increase has been monitored over both the Central Cretan and Eastern Ionian Seas starting from the middle of 2008 and 2009 respectively. This could possibly be attributed to changes in the intermediate water masses of the Eastern Mediterranean, without ruling out the possibility of water mass exchanges between the two basins.

  7. Otolith morphometry and population parameters of red porgy, Pagrus pagrus (Linnaeus, 1758 in Saros Bay (North Aegean Sea.

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    Ali İşmen

    2015-12-01

    Full Text Available Bu çalışmada, Kuzey Ege Denizi’nde (Saroz Körfezi Fangri balığının toplam boy (TL ile toplam ağırlık (TW arasındaki ilişki, yaş, büyüme ve otolit boyu (OL - otolit ağırlığı (OW, balık boyu (TL - otolit boyu (OL, balık ağırlığı (TW - otolit boyu (OL, otolit boyu (OL - otolit genişliği (OWi arasındaki morfometrik ilişkiler incelenmiştir. Toplam 100 adet balık üzerinde yapılan ölçümlerde minimum boy 9,6 cm, maksimum boy 44,4 cm; minimum ağırlık 17,1 g, maksimum ağırlık 1372,5 g olarak tespit edilmiştir. Otolit ağırlığı minimum 0,0181 g, maksimum 0,1456 g; otolit boyu minimum 0,52 cm, maksimum 1,17 cm olarak ölçülmüştür. Boy-ağırlık ilişkisi TW=0,021*TL2,885 (r2=0,98, otolit boyu - otolit ağırlığı OW=0,105*OL2,609 (r2=0,92, toplam boy - otolit boyu OL=0,024*TL+0,249 (r2=0,83 otolit boyu - toplam ağırlık OL=0,235*TW0,237 (r2=0,81 otolit boyu - otolit genişliği OWi=0.501*OL+0.116 (r2=0.832 ilişkileri tespit edilmiştir. En büyük yaş 9 olarak belirlenmiş, von Bertalanffy büyüme parametreleri L∞=51,59 cm, K=0,12 yıl-1ve t0= -1,13 yıl olarak hesaplanmıştır

  8. Establishing physiographic provinces for an integrative approach of the coastal zone management - The case of Rhodes Island, Aegean Sea, Greece

    Science.gov (United States)

    Anagnostou, Vasileios; Angelos Hatiris, Georgios; Sioulas, Andreas

    2017-04-01

    The coastal zone is a dynamic natural system affected by terrestrial and marine processes as well as human intervention. The sediments derived by the land and supplied by the adjacent catchment are reworked and distributed according to the prevailing hydrodynamic regime. Based on inland and coastal physiography of Rhodes Island, six (6) main Physiographic Provinces were identified, which incorporate 56 main drainage basins and 168 interfluves. Moreover, the variety of coastal types was mapped and the total length of the island's coastline ( 285 km) was measured by using geospatial tools (ArcGIS and Google Earth). The coastline is comprised of depositional sandy beaches (44.5%), rocky coasts (47%) and coasts altered from anthropogenic constructions (8.5%). The Physiographic Provinces were defined in order to facilitate an Integrated Coastal Zone Management (ICZM) scheme for Rhodes Island and also adaptation measures. Overexploitation of the island's natural coastal environment by the tourism industry, mainly in the northern and northeastern parts of the island, left a series of adverse effects on the coastal area, such as erosion of beaches, water and energy overconsumption and land degradation.

  9. Expanding extension, subsidence and lateral segmentation within the Santorini - Amorgos basins (central - south Aegean Sea, Greece) during Quaternary.

    Science.gov (United States)

    Nomikou, Paraskevi; Hübscher, Christian; Papanikolaou, Dimitris; Farangitakis, Georgios-Pavlos; Ruhnau, Marcel; Lampridou, Danai

    2017-04-01

    New bathymetric and seismic reflection data from the Santorini-Amorgos Tectonic Zone in the southern Cyclades have been analysed and a description of the morphology and tectonic structure of the area has been presented. The basins of Anhydros, Amorgos and Santorini-Anafi have been distinguished together with the intermediate Anhydros Horst within the NE-SW oriented Santorini-Amorgos Tectonic Zone which has a length of 60-70km and a width of 20-25km. The basins represent tectonic grabens or semigrabens bordered by the active marginal normal faults of Santorini-Anafi, Amorgos, Ios, Anhydros and Astypalaea. The Santorini-Anafi, Amorgos and Ios marginal faults have their footwall towards the NW where Alpine basement occurs in the submarine scarps and their hangingwall towards the southeast, where the Quaternary sediments have been deposited with maximum thickness of 700m. Six sedimentary units 1-6 have been distinguished in the stratigraphic successions of the Santorini-Anafi and the westerrn Anhydros Basin whereas in the rest area only the upper four units 3-6 have been deposited. This shows the expansion of the basin with subsidence during the Quaternary due to ongoing extension in a northwest-southeast direction. Growth structures are characterised by different periods of maximum deformation as this is indicated by the different sedimentary units with maximum thickness next to each fault. Transverse structures of northwest-southeast direction have been identified along the Santorini-Amorgos Tectonic Zone with distinction of the blocks/segments of Santorini, Anhydros/Kolumbo, Anhydros islet and Amorgos. Our study shows that the active geodynamic regime is an ongoing process evolved during the last 2-3myears with well-defined periods of expanding, extension and subsidence of a rift zone which however has been segmented by transverse structures separating different geodynamic processes of faulting, tilting, volcanism and morphogenesis.

  10. Geodetic evidence and modeling of a slow, small-scale inflation episode in the Thera (Santorini) volcano caldera, Aegean Sea

    Science.gov (United States)

    Stiros, Stathis C.; Psimoulis, Panos; Vougioukalakis, George; Fyticas, Michalis

    2010-11-01

    Analysis of a radial geodetic monitoring record indicated small-scale inflation of the NW part of the Thera (Santorini) caldera (up to 10 cm baseline length increase) between 1994 and 2000, corresponding to up to 2 * 10 -5 strain, and subsequent stabilization especially after 2006, as GPS data indicate. The southern part of the caldera on the contrary remained practically stable. This partial caldera inflation was assigned to slow magma intrusion which was not associated with changes in the seismicity. Using a stochastic approach based on numerical analysis and the theory of graphs and sets, the Mogi source of this magmatic activity was identified between the Nea Kammeni and the Therasia islets, along a major tectonovolcanic lineament, at a depth of around 1 km, or possibly 5.5 km, it remained stable during the whole small-scale inflation period and was associated with small-scale pressure changes. Slow-deformation events have been observed in other volcanoes as well, but they were associated with abrupt seismicity changes.

  11. Equilibrium and Disequilibrium of 230Th-238U in Zircon from the Minoan Eruption, Santorini, Aegean Sea, Greece

    Science.gov (United States)

    Schmitt, A. K.; Stockli, D. F.; Song, E. J.; Storm, S.

    2016-12-01

    The Minoan eruption (ca. 1600 BCE; 40-80 km3 dense rock equivalent) occurred after a ca. 18 ka period of dormancy followed by rapid reinvigoration through arrival of new magma from deep reservoirs colliding with evolved magmas in shallow storage. Although zoned phenocrysts indicate brief timescales ranging between years to decades for final pre-eruptive magma recharge and mixing, it remains unclear how magma accumulation vs. crystallization were balanced in the subvolcanic reservoir during the preceding inter-eruptive cycle. To directly probe magma presence over the repose interval prior to the Minoan eruption and further back in time, we reconnoitered the potential of U-Th zircon geochronology to date the crystallization of individual zircon crystals from pumice from the Minoan eruption. Zircon crystals were extracted from composite pumice samples (several kg each) from basal fall out deposits using gravity and magnetic separation. Etching in cold HF removed adherent glass and revealed the shape of crystals, which were pressed into indium metal to expose unpolished rims to the ion beam of a CAMECA IMS 1270 secondary ionization mass spectrometer. Adherent glass was ubiquitous, indicating that crystals were in contact with melt at the time of eruption. Six of 18 crystals were in 230Th/238U secular equilibrium, two crystals yielded ages of ca. 160 ka, and the remaining rims dated between eruption age and ca. 20 ka. Low Th/U of some secular equilibrium zircon suggests recycling of metamorphic basement zircon, which is also indicated by the presence of rutile in heavy mineral separates. U-Th dates also reveal recycling of zircon from Pleistocene intrusions that likely represent left-over magma from antecedent eruption cycles. We tentatively interpret the dominant zircon population with near-eruption to ca. 20 ka ages to indicate continuous melt presence underneath Santorini during the last repose interval. Distinguishing a hiatus in zircon crystallization between 20 ka and 160 ka from continuous presence of a crystal mush capable of crystallizing zircon throughout the late Pleistocene requires further analyses. A corollary of mixed zircon populations of heterogeneous provenance in Minoan pumice is that the age significance of U-series data for major phases analyzed in bulk is suspect.

  12. Modelling the 2013 North Aegean (Greece) seismic sequence: geometrical and frictional constraints, and aftershock probabilities

    Science.gov (United States)

    Karakostas, Vassilis; Papadimitriou, Eleftheria; Gospodinov, Dragomir

    2014-04-01

    The 2013 January 8 Mw 5.8 North Aegean earthquake sequence took place on one of the ENE-WSW trending parallel dextral strike slip fault branches in this area, in the continuation of 1968 large (M = 7.5) rupture. The source mechanism of the main event indicates predominantly strike slip faulting in agreement with what is expected from regional seismotectonics. It was the largest event to have occurred in the area since the establishment of the Hellenic Unified Seismological Network (HUSN), with an adequate number of stations in close distances and full azimuthal coverage, thus providing the chance of an exhaustive analysis of its aftershock sequence. The main shock was followed by a handful of aftershocks with M ≥ 4.0 and tens with M ≥ 3.0. Relocation was performed by using the recordings from HUSN and a proper crustal model for the area, along with time corrections in each station relative to the model used. Investigation of the spatial and temporal behaviour of seismicity revealed possible triggering of adjacent fault segments. Theoretical static stress changes from the main shock give a preliminary explanation for the aftershock distribution aside from the main rupture. The off-fault seismicity is perfectly explained if μ > 0.5 and B = 0.0, evidencing high fault friction. In an attempt to forecast occurrence probabilities of the strong events (Mw ≥ 5.0), estimations were performed following the Restricted Epidemic Type Aftershock Sequence (RETAS) model. The identified best-fitting MOF model was used to execute 1-d forecasts for such aftershocks and follow the probability evolution in time during the sequence. Forecasting was also implemented on the base of a temporal model of aftershock occurrence, different from the modified Omori formula (the ETAS model), which resulted in probability gain (though small) in strong aftershock forecasting for the beginning of the sequence.

  13. The accretionary model for orogenesis and its application to the evolution of the Aegean crust

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    Lister, G; Forster, M [Research School of Earth Sciences, Australian National University, Canberra 0200 (Australia)], E-mail: gordon.lister@anu.edu.au

    2008-07-01

    Both modern and ancient mountain belts have characteristic 'fingerprints' determined by the sequencing of the tectonic mode switches that took place during their evolution. Accretionary Tethyan style orogenesis is characterized by a sequence of 'push-pull' tectonic mode switches associated with the accretion of a succession of continental ribbons. The origin of the extensional episodes can be found in the driving forces provided by rapid 'roll-back' of adjacent subducting slabs. Such slabs appear to be created during (indentation-triggered) foundering of the marginal basins that typified ancient Tethys. We suggest individual accretion events were marked by short-lived episodes of high-pressure metamorphic mineral growth, followed by the development of km-scale extensional shear zones. The mode switches are often evident in tectonic sequence diagrams as F{sub R} {delta} SZ sequences, where F{sub R} are recumbent folds, {delta} a growth episode of metamorphic minerals, and SZ are extensional shear zones. Microstructures imply that mineral growth in the {delta} events was static, or that they took place with such rapidity that deflections of fabric due to accumulating strain are not evident. Visually, the appearance of static growth was maintained. In our examination of the Cycladic Eclogite-Blueschist Unit at least three separate F{sub R} {delta} SZ sequences have been documented. The evolution of the Aegean crust was thus marked by a complexity that will not be unravelled without modern microstructurally focussed geochronology, and geospeedometry, in particular using the {sup 40}Ar/{sup 39}Ar isotopic system.

  14. Traditionally used wild edible greens in the Aegean Region of Turkey

    Directory of Open Access Journals (Sweden)

    Yunus Dogan

    2012-12-01

    Full Text Available Turkey has the largest coastal area in the Mediterranean, possesses an extraordinarily rich flora, and a great traditional knowledge. This diversity of plants naturally affects the traditional use of plants and is reflected in the rich Turkish cuisine. Consequently, the Mediterranean Diet (whose typical components are wild greens constitutes one of the important elements of Turkish cuisine. For this reason, the aim of this study was to determine the consumption of wild edible green plants for the Aegean Region of Turkey and to establish the similarities to or differences from consumption in other regions and other cuisine in the Mediterranean Basin. This study compiles and evaluates the ethnobotanical data currently available. There were 111 taxa that were identified as wild edible greens in the study area belonging to 26 different families. Asteraceae (21 taxa were the most commonly consumed as food. It was followed by Boraginaceae with 19 taxa, Apiaceae with 15 taxa and Lamiaceae with 7 taxa, respectively. Rumex and Erodium were the most represented genera with 4 species. Tamus communis and Asparagus acutifolius, Mediterranean elements and distributed in all of the Mediterranean Basin, are among the most widely consumed wild plants in the area. Wild edible plants are consumed in a variety of ways. The most common type of consumption (79 taxa was in salads. The fact that the majority of the plants used in the area are consumed in salads shows the close relationship between the local diet and the concept of the Mediterranean Diet. As a result, very promisingly, there is a renewed or increasing interest in consuming wild food plants as part of this diet.

  15. A distinct source and differentiation history for Kolumbo submarine volcano, Santorini volcanic field, Aegean arc.

    Science.gov (United States)

    Klaver, Martijn; Carey, Steven; Nomikou, Paraskevi; Smet, Ingrid; Godelitsas, Athanasios; Vroon, Pieter

    2016-08-01

    This study reports the first detailed geochemical characterization of Kolumbo submarine volcano in order to investigate the role of source heterogeneity in controlling geochemical variability within the Santorini volcanic field in the central Aegean arc. Kolumbo, situated 15 km to the northeast of Santorini, last erupted in 1650 AD and is thus closely associated with the Santorini volcanic system in space and time. Samples taken by remotely-operated vehicle that were analyzed for major element, trace element and Sr-Nd-Hf-Pb isotope composition include the 1650 AD and underlying K2 rhyolitic, enclave-bearing pumices that are nearly identical in composition (73 wt.% SiO2, 4.2 wt.% K2O). Lava bodies exposed in the crater and enclaves are basalts to andesites (52-60 wt.% SiO2). Biotite and amphibole are common phenocryst phases, in contrast with the typically anhydrous mineral assemblages of Santorini. The strong geochemical signature of amphibole fractionation and the assimilation of lower crustal basement in the petrogenesis of the Kolumbo magmas indicates that Kolumbo and Santorini underwent different crustal differentiation histories and that their crustal magmatic systems are unrelated. Moreover, the Kolumbo samples are derived from a distinct, more enriched mantle source that is characterized by high Nb/Yb (>3) and low (206)Pb/(204)Pb (<18.82) that has not been recognized in the Santorini volcanic products. The strong dissimilarity in both petrogenesis and inferred mantle sources between Kolumbo and Santorini suggests that pronounced source variations can be manifested in arc magmas that are closely associated in space and time within a single volcanic field.

  16. Mitochondrial DNA Reveals Genetic Structuring of Pinna nobilis across the Mediterranean Sea

    Science.gov (United States)

    Sanna, Daria; Cossu, Piero; Dedola, Gian Luca; Scarpa, Fabio; Maltagliati, Ferruccio; Castelli, Alberto; Franzoi, Piero; Lai, Tiziana; Cristo, Benedetto; Curini-Galletti, Marco; Francalacci, Paolo; Casu, Marco

    2013-01-01

    Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units. PMID:23840684

  17. Changing Arctic: A Strategic Analysis of United States Arctic Policy and the United Nations Convention on the Law of the Sea

    Science.gov (United States)

    2013-05-01

    accomplished Canadian academic said: “What the Aegean Sea was to antiquity, what the Mediterranean was to the Roman world, what the Atlantic Ocean was to...Linda Jakobson and Stockholm International Peace Research Institute., "China Prepares for an Ice-Free Arctic," Stockholm International Peace Research...Quarterly (Jul 1, 2012): 45. Jakobson , Linda and Stockholm International Peace Research Institute. "China Prepares for an Ice-Free Arctic." Stockholm

  18. [MEFV gene mutation spectrum in familial Mediterranean fever (FMF) : a single center study in the Aegean region of Turkey].

    Science.gov (United States)

    Coker, I; Colak, A; Yolcu, I; Türkön, H; Nalbantoglu, S M

    2011-08-01

    Familial Mediterranean fever (FMF), an autosomal recessive autoinflammatory disorder, is characterized by recurrent, self-limiting fever and serositis which is frequently seen in Mediterranean populations. In this study, we retrospectively evaluated the MEFV gene mutation distribution of 883 citizens of the Aegean region with preliminary diagnosis of FMF who were referred to the Tepecik Research and Education Hospital's Tissue Typing and Molecular Diagnostic Laboratory (Izmir, Turkey) between 2006 and 2009. The FMF Strip Assay® (ViennaLab Diagnostics, Vienna, Austria) was used to determine the 12 most common MEFV gene mutations in patients prediagnosed with FMF. Allelic frequencies of the major mutations in the mutation positive groups, including M694V, E148Q, M680I(G>C), and V726A, accounted for 48.4, 16.5, 13.5, and 9.7%, respectively. The M694V mutation was found to be the most common mutation among FMF patients in the Aegean region, which is in accordance with mutation studies reported from other regions of the country and different ethnic populations. An English full-text version of this article is available at SpringerLink as supplemental.

  19. The larvae of Hydropsyche rhadamanthys Malicky 2001 and Hydropsyche sarpedon Malicky 2001 (Trichoptera: Hydropsychidae), endemics of Crete (South Aegean, Greece), with notes on their ecology.

    Science.gov (United States)

    Karaouzas, Ioannis

    2016-04-04

    The larvae of Hydropsyche rhadamanthys Malicky 2001 and Hydropsyche sarpedon Malicky 2001, endemics of Crete Island, Greece, are described for the first time. The diagnostic features of the species are described and illustrated, and some information regarding their ecology is included. In addition, diagnostic characters for larvae of the known Aegean Hydropsyche species are provided.

  20. Lifestyle and health determinants of cardiovascular disease among Greek older adults living in Eastern Aegean Islands: An adventure within the MEDIS study

    Directory of Open Access Journals (Sweden)

    Alexandra Foscolou

    2016-11-01

    Conclusions: Overall, CVD risk seems to be low among Eastern Aegean Islanders; certain differences in CVD risk factors exist between Greek islanders and their counterparts living in Gökçeada, and those differences may be attributed to various environmental, cultural and lifestyle factors.

  1. The Rupture Process of the 2014 Mw6.8 Gökçeada, North Aegean Earthquake Revealed from Teleseismic and Near-Source Waveforms and GPS Vectors

    Science.gov (United States)

    Ozgun Konca, Ali; Ergintav, Semih; Cetin, Seda; Dogan, Ugur; Cakir, Ziyadin; Karabulut, Hayrullah; Reilinger, Robert; Tari, Ergin

    2016-04-01

    We studied the source characteristics and of the Mw 6.8 2014 Gökçeada, North Aegean Sea Earthquake using teleseismic P and near-source ground displacement waveforms along with the GPS displacement vectors. Our model shows that the 2014 earthquake has similar duration to the 1999 Mw7.4 Izmit Earthquake, despite having 2 orders of magnitude smaller seismic moment. The finite-fault model shows three asperities; a large one toward the west of the hypocenter and two smaller asperities toward east. In consistence with the long duration of the waveforms, the rupture extends for 80 km along strike. The 2014 Earthquake is a case where several distinct asperities have ruptured leading to low stress drop, a complex moment rate function with long duration and longer than expected rupture length compared to the size of the earthquake. A relocated aftershock distribution shows that most of the aftershocks are located at both ends of the rupture zone and in between the asperities of the mainshock.

  2. Development of a behavioural framework for analyzing employment mobility decisions in island areas: the case of the Aegean Islands, Greece

    Directory of Open Access Journals (Sweden)

    Eleni Kitrinou

    2014-11-01

    Full Text Available This paper proposes a theoretical framework to model employment mobility in island areas. It aims at identifying the critical factors affecting the decision of the employees to relocate their workplace to an island area, given a possible residential relocation. Emphasis is given to the role of transport and telecommunications systems on the region’s connectivity and accessibility. Discrete choice models are developed, using both observed and latent variables for the workplace relocation decision to the Aegean island area in Greece. Data was collected in the year 2012 from 518 Greek employees. Findings indicate the importance of the role of transport and telecommunications systems for employment mobility in island areas. The estimated choice models identified profiles of the employees who are prone to: a keep their current workplace; b relocate their workplace to the island area; c change occupation after residential relocation. Finally, the sample enumeration method integrates the models’ results across all Greek employees.

  3. Evaluations of heavy metal pollution in sediment and Mullus barbatus from the Izmir Bay (Eastern Aegean) during 1997-2009.

    Science.gov (United States)

    Kucuksezgin, Filiz; Kontas, Aynur; Uluturhan, Esin

    2011-07-01

    Izmir Bay is one of the great natural bays of the Mediterranean. The surface sediment and fish samples were collected during 1997-2009. The sediment concentrations of inner bay showed significant enrichments during sampling periods. Outer and middle bays exhibited low levels of metal enrichments except the estuary of Gediz River. The concentrations were generally higher than the background levels from the Mediterranean and Aegean except Cd and Pb levels gradually decreased. Metal EF is used as an index to evaluate anthropogenic influences of metals in sediments. Maximum metal enrichment was found for Hg in the outer bay, while Pb indicated maximum enrichment in the middle-inner bays. Metal levels were evaluated in sediments in accordance with the numerical SQG of the USEPA. The levels of fish tissues were lower than the results reported from polluted areas of the Mediterranean. The highest BAFs were detected for Hg and Cd in fish.

  4. Βοοκ Review of "Liquid and Multiple: Individuals and Identities in the Thirteenth-Century Aegean, ed. G. Saint-Guillain, D. Stathakopoulos, Monographies 35, Paris 2012

    Directory of Open Access Journals (Sweden)

    Εφη ΡΑΓΙΑ

    2015-05-01

    Full Text Available This is a review of the volume "Liquid and Multiple: Individuals and Identities in the Thirteenth-Century Aegean, ed. G. Saint-Guillain, D. Stathakopoulos, Monographies 35, Paris 2012.

  5. Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, Western Turkey): Implications for Aegean tectonics

    Science.gov (United States)

    Catlos, E. J.; Baker, C.; Sorensen, S. S.; Çemen, I.; Hançer, M.

    2009-04-01

    The Menderes Massif (western Turkey) is an important metamorphic core complex located in the Aegean region; geochemical and geochronological data from this extensional domain facilitates our understanding of large-scale extension of the Earth's lithosphere. S-type, peraluminous granites (Salihli and Turgutlu) that intrude the Alasehir detachment which bounds the northern edge of the central Menderes Massif may have been generated due to subduction of the Eastern Mediterranean floor along the Hellenic trench. In situ Th-Pb ion microprobe monazite ages from the granites range from 21.7±4.5 Ma to 9.6±1.6 Ma (±1s). The range is consistent with cathodoluminescence (CL) imagery that document complex textures within the samples. Salihli and Turgutlu granites share many similar characteristics, including multiple generations of plagioclase (some with shocked cores consistent with magma mixing), plagioclase replacing K-feldspar and the development of myrmekite, clear evidence for fluid infiltration, and multiple generations of microcracks and microfaults. The granites may have evolved from compositionally distinct magma sources, as Salihli samples in general contain allanite as the major accessory mineral, whereas Turgutlu granites contain monazite. However, the CL imagery document similar alteration textures. Ages reported here are similar to dates constraining extension reported elsewhere in the Aegean, but indicate a level of complexity when linking movement within the Menderes Massif to the large-scale geodynamic processes that created other metamorphic core complexes in the region. Difficulties exist in linking the ages obtained from the granites to specific tectonic events due to the presence of secondary alteration textures, generations of mineral growth, and multiple episodes of deformation.

  6. Clinical Characteristics of the Premature Ejaculation Sufferers in Aegean Region of the Turkey: A Multicentre, Observational Study

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    Ahmet Cihan

    2014-11-01

    Full Text Available Demonstration of the intra-vaginal ejaculation latency time (IELT distribution in male subjects and its clinical expressions among couples in the Aegean region of the Turkey. Materials and Methods Subjects were recruited to the study from six different urologic centers in the Aegean region. During the enrollment period subjects were recruited in to two group according to presence of premature ejaculation (PE. PE diagnosis was made according to DSM-4 definition. Subjects and their partners were evaluated with patient reported outcome measures (PRO related to the ejaculation-based questionnaire (Premature ejaculation patient profile questionnaire -PEPQ. Stopwatch measurements were also asked from each couple to record intravaginal ejaculation latency time (IELT. Couples who completed two clinical visits with 4 wk interval were recruited to the data analysis. Results Among 141 eligible subjects, mean age was 36.5±9.7 years and mean partner age was 32.9±9.8 years. Following the initial evaluation 80 subjects recruited to group 1(PE and 41 subjects recruited to the group 2 (non-PE. Geometric mean IELT of the subjects was significantly differed between PE and non- PE group (64.7±66.8 vs. 521.5±414.7 seconds, p<0.001. All of the PEPQ domain scores were also differed between groups. Subjects in the PE group gave poor ratings than non-PE subjects. Partner responses were similar pattern. Correlation analyses of the PEPQ scores demonstrated significant positive correlations between “perceived control over ejaculation” and “satisfaction with sexual intercourse” domains of the PEPQ and with IELT. Conclusion Geographic distribution of IELT and its impacts among couples by the several subjective aspects of PRO measures should be assessed during PE investigation

  7. Space-time variability of alkalinity in the Mediterranean Sea

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    G. Cossarini

    2014-09-01

    Full Text Available The paper provides a basin assessment of the spatial distribution of ocean alkalinity in the Mediterranean Sea. The assessment is made using a 3-D transport-biogeochemical-carbonate model to integrate the available experimental findings, which also constrains model output. The results indicate that the Mediterranean Sea shows alkalinity values that are much higher than those observed in the Atlantic Ocean on a basin-wide scale. A marked west-to-east surface gradient of alkalinity is reproduced as a response to the terrestrial discharges, the mixing effect with the Atlantic water entering from the Gibraltar Strait and the Black Sea water from Dardanelles, and the surface flux of evaporation minus precipitation. Dense water production in marginal seas (Adriatic and Aegean Seas, where alkaline inputs are relevant, and the Mediterranean thermohaline circulation sustains the west-to-east gradient along the entire water column. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 μmol kg−1 that is driven both by physical and biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships. In regions of freshwater influence, the two measures are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open seas. Alkalinity always is much higher than in the Atlantic waters, which might indicate a higher than usual buffering capacity towards ocean acidification, even at high concentrations of dissolved inorganic carbon.

  8. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

    Science.gov (United States)

    Parinos, C.; Gogou, A.; Bouloubassi, I.; Pedrosa-Pàmies, R.; Hatzianestis, I.; Sanchez-Vidal, A.; Rousakis, G.; Velaoras, D.; Krokos, G.; Lykousis, V.

    2013-09-01

    Surface sediments collected from deep basins (1018-4087 m depth) of the eastern Mediterranean Sea (Ionian Sea, southern Aegean Sea and northwestern Levantine Sea) were analyzed for aliphatic and polycyclic aromatic hydrocarbons as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons, n-alkanes and the unresolved complex mixture (UCM) of aliphatic hydrocarbons varied significantly, ranging from 1.34 to 49.2 μg g-1, 145 to 4810 ng g-1 and 0.73 to 36.7 μg g-1, respectively, while concentrations of total polycyclic aromatic hydrocarbons (PAHs) ranged between 11.6 and 223 ng g-1. Molecular profiles of determined hydrocarbons reflect a mixed contribution from both natural and anthropogenic sources in deep-sea sediments of the eastern Mediterranean Sea, i.e., terrestrial plant waxes, degraded petroleum products, unburned fossil fuels and combustion of grass, wood and coal. Hydrocarbon mixtures display significant variability amongst sub-regions, reflecting differences in the relative importance of inputs from various sources and phase associations/transport pathways of individual hydrocarbons that impact on their overall distribution and fate. Hydrocarbon concentrations correlated significantly with the organic carbon content of sediments, indicating that the latter exerts an important control on their transport and ultimate accumulation in deep basins. Additionally, water masses' circulation characteristics also seem to influence the regional features and distribution patterns of hydrocarbons. Our findings highlight the role of deep basins/canyons as repositories of both natural and anthropogenic chemical species.

  9. COMPARISON OF MORPHOMETRIC CHARACTERS OF TWAITE SHAD (ALOSA FALLAX NILOTICA, GEOFFROY SAINT-HILAIRE, 1808 AMONG THREE AREAS IN TURKISH SEAS.

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    TURAN C.

    2001-07-01

    Full Text Available Degree of differentiation among populations of twaite shad, Alosa fallax nilotica, in Turkish territorial waters was evaluated with the truss morphometric system using Discriminant Function (DFA and Principal Component Analyses (PCA. Approximately 40 individuals were collected from each sea to represent regions. In DFA, the proportion of correctly classified Eastern Mediterranean sea sample to their original group was highest (90 % with a high overall random assignment of individuals into their original population (78 %. Plotting discriminant function 1 (DF1 and discriminant function 2 (DF2 explained 100 % of total between group variability and clearly discriminated Eastern Mediterranean sea sample from the Baltic and Aegean sea samples, which were over plotted. This findings was also supported in multivariate analysis of variance. PCA revealed that the observed differences were mainly from posterior morphometric measurements of the fish. The patterns of morphological differentiation suggested that there is limited exchange of individuals among areas to homogenize populations phenotypically from the Black and Aegean seas to Eastern Mediterranean sea.

  10. On the Occurrence and Established Populations of the Alien Polychaete Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae in the Sea of Marmara and the Bosphorus Strait (Turkey

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    S.U. KARHAN

    2012-12-01

    Full Text Available The present paper reports the first occurrence of Polydora cornuta in the Bosphorus Strait and its finding in a new locality in the Sea of Marmara, providing a link with its Aegean and Black Sea populations. The probable vector for the introduction of P. cornuta into the Sea of Marmara is shipping through the Dardanelles Strait. Both soft and hard-bottom populations were examined and the importance and prevalence of this species within the native macrozoobenthic communities were elucidated. Its abundance ranged between 40 and 3390 ind.m-2 (mean:1320 ±1199.45 SD and its percent contribution to the total faunal populations ranged between 3.31 and 75.56 (mean:27.79 ±25.00 SD in the Sea of Marmara softbottom community. During the sampling period, P. cornuta contributed little to the total faunal abundance of the hard-bottom communities in the Bosphorus Strait. Its mean abundance in the hard substrate ranged between 8.33 and 1000 ind.m-2 (mean:117.36 ±279.73 SD and its percent contribution to the total faunal populations ranged between 0.02 and 21.86 (mean:2.07 ±6.25 SD.The role of this invasive species in the soft-bottom macrobenthic community at an organically enriched site examined in the Sea of Marmara is highlighted, and a comparison with Aegean Sea populations of the species is also included.

  11. Sea level changes according to data of tide gauge station and its relationship with elements of climate in eastern Mediterranean: 1972-2009

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    Muhammed Zeynel Öztürk

    2011-08-01

    Full Text Available Mediterranean Sea is one of the areas that indicated the greatest increase in sea level rise during the 20th century. The eastern Mediterranean had also greatest increase in sea level with in the Mediterranean Sea. In this study, sea level data observed at 11 tide gauge stations located in the Levantine Sea, Cretan Sea and south of the Aegean Sea and gridded climatological data were used in the eastern Mediterranean Sea. In this frame, monthly and annual variations and trends in average, average maximum and average minimum sea levels data and mean air temperature, mean sea level pressure and total precipitation series were investigated. According to the results of analysis, there are statistically significant increase trends in temperature and all sea level series. These trend rates are of +1.57 mm/year in average sea level, +1.89 mm/year in average maximum, +1.36 mm/year in average minimum and 0.026 ºC/year in temperature. According to the long-term averages, annually amplitude is 14.9 cm, while, the highest and the lowest levels of amplitude are reached in August and March, respectively. According to the interannual average maximum and minimum sea level values, amplitude of 36.5 cm is seen.

  12. The changes of fatty acid and amino acid compositions in sea bream (Sparus aurata) during irradiation process

    Energy Technology Data Exchange (ETDEWEB)

    Erkan, Nuray [Faculty of Fisheries, Department of the Seafood Processing and Quality Control, Istanbul University, Ordu, Cad. No. 200, 34470 Laleli/Istanbul (Turkey)]. E-mail: nurerkan@istanbul.edu.tr; Ozden, Ozkan [Faculty of Fisheries, Department of the Seafood Processing and Quality Control, Istanbul University, Ordu, Cad. No. 200, 34470 Laleli/Istanbul (Turkey)]. E-mail: ozden@istanbul.edu.tr

    2007-10-15

    Aqua cultured fish (sea bream) were irradiated by Cobalt-60 at commercial irradiation facility at dose of 2.5 and 5 kGy at 2-4 deg. C. The proximate composition, fatty acid and amino acid composition changes of irradiated aqua cultured sea bream (Sparus aurata) of Aegean Sea were investigated. Total saturated (28.01%) and total monounsaturated (28.42%) fatty acid contents of non-irradiated decreased content of 27.69-27.97% for 2.5 kGy irradiated groups and increased content of 28.33-28.56% for 5 kGy irradiated groups after irradiation process. Total polyunsaturated fatty acid content for irradiated samples was lower than that of non-irradiated samples. Aspartic acid, glutamic acid, serine, glycine, arginine, alanine, tyrosine, cystine, tryptophan, lysine and proline contents for 2.5 and 5 kGy irradiated sea bream are significantly different (p<0.05)

  13. The Strategic Value of Aegean Islands and Today’s NATO Policy

    Science.gov (United States)

    1988-04-01

    Soviet Navy In the ,ear, add "irwrtant ccm- p i ex itie The Psycological ir1pact of the geographical ccnfigllratlmr, uponi N/vTtrQ States ii ttic- area...political threat in the Mediterranean and an increasing politico -naval challenge to the American Sixth Fleet in the inlcnc sea. (4:LI) Of capital importance...time even approaching the outskirts of the Ottoarn capital . During the Balkan War of 1912-13, Forces reached the outer defense girdle of Constantinople

  14. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system

    Science.gov (United States)

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N.; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-01-01

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2–dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10−6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano. PMID:27311383

  15. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system

    Science.gov (United States)

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N.; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-06-01

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2-dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10-6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano.

  16. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system.

    Science.gov (United States)

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-06-17

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report (3)He/(4)He measurements in CO2-dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a (3)He/(4)He signature of at least 7.0 Ra (being Ra the (3)He/(4)He ratio of atmospheric He equal to 1.39×10(-6)), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like (3)He/(4)He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano.

  17. First records, rediscovery and compilation of deep-sea echinoderms in the middle and lower continental slope of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Ariadna Mecho

    2014-06-01

    Full Text Available This study provides a compilation of all available information on deep-sea echinoderms from the middle and lower slopes of the Mediterranean Sea, with the aim of providing a unified source of information on the taxonomy of this group. Previous records of species are updated with new data obtained from 223 trawl hauls conducted in 11 cruises within the northwestern Mediterranean Sea between 800 m and 2845 m depth. Valid names, bathymetric ranges and geographic distributions are given for all species. The new data report, for the first time, the presence of the Atlantic echinoid Gracilechinus elegans (Düben and Koren, 1844 in the Mediterranean Sea. We also report the presence of the endemic holothurians Hedingia mediterranea (Bartolini Baldelli, 1914, dredged only once previously in 1914 in the Tyrrhenian Sea, and Penilpidia ludwigi (von Marenzeller, 1893, known previously only from three samples, two in the Aegean Sea and one in the Balearic Sea. Additionally, the deeper limits of the bathymetric distribution of four species have been expanded: the asteroid Ceramaster grenadensis (Perrier, 1881 to 2845 m; the echinoid Brissopsis lyrifera (Forbes, 1841 to 2250 m; and the holothurians Hedingia mediterranea and Holothuria (Panningothuria forskali Delle Chiaje, 1823, to 1500 m and 850 m, respectively.

  18. Relative sea-level change in the central Cyclades (Greece) since the Early Bronze Age

    Science.gov (United States)

    Draganits, E.

    2012-04-01

    The Aegean is a focus of important cultural achievements in Europe since the Neolithic period. The resulting abundance of archaeological remains, many of them below sea-level represent an advantageous area for the study of local relative sea-level change. We have carried out detailed mapping of Despotiko Island (SW of Antiparos) and its surrounding. Despotiko is situated almost exactly in the center of the Cyclades (as defined nowadays), more so than Delos, and therefore is very well suited for sea-level studies of the Cyclades. This beneficial location, combined with a spacious and protected bay, additionally may explain its former importance as stepping-stone in the Aegean Sea. The island is uninhabited at present, but Early Bronze Age settlement sites and graveyards as well as a large Archaic sanctuary proof its former importance. The sanctuary is situated on a gently northeast dipping slope in the northeast part of Despotiko, in range of sight of the Órmos Despotiko. Since 1997 large parts of this important sanctuary have been excavated during several excavation campaigns. Tectonically, Despotiko, Antiparos and Paros, belong to the Attic-Cycladic Crystalline of the Central Hellenides, a stack of metamorphic tectonic nappes, mainly comprising variable types of gneiss, schist, marble and amphibolite, and tectonic slices of unmetamorphosed sediments on top, separated by low-angle normal faults from the metamorphic units below. Submerged archaeological structures at the sea bottom of the Órmos Despotiko, a Classical marble inscription from the sanctuary and partly submerged agriculture trenches at the east coast Despotiko, indicate that the relative sea-level in this area was some 3 m lower during the Early Bronze Age and still more than 1 m lower during Classical time. These values of relative sea-level rise indicate a subsidence component additional to the global sea-level rise in the investigated time period. Neglecting possible vertical tectonic movements and

  19. Population Genetics of European Anchovy (Engraulis encrasicolus L. in the Seas of Turkey Based on Microsatellite DNA

    Directory of Open Access Journals (Sweden)

    Fevzi Bardakci

    2014-06-01

    Results: In this study, 13 microsatellite loci in 541 samples were analysed for determination of genetic structure of anchovy along Turkish coasts. The genetic variability was high among population, the average alleles numbers per locus per population ranged from 11.0 to 22.8. Observed heterozygosity per population was ranged from 0.612 (Mersin to 0.733 (İstanbul while expected heterozygosity was ranged from 0.774 (Mersin to 0.823 (Perşembe. The highest genetic distance was found between Antalya and Trabzon populations (FST=0.06949, the lowest between Antalya and İskenderun populations (0,00010. Analyses of 13 microsatellite loci were showed that there was low population structuring among all anchovy population (Fst: 0,024; SE 0,005. Although high genetic diversities was detected, for most loci with most populations were showed Hardy-Weinberg disequilibrium. Genetic distance analyses showed up Mediterranean specimens were highly distinct from Aegean and Black sea populations. Aegean populations were closer to Black sea populations because of higher gene flow between them rather than Mediterranean. A STRUCTURE computer program was indicated the presence of four possible genetic groups in Turkish territorial waters. Conclusions: Data to obtained from this study has found useful for the identification of genetic structuring of European anchovy distributed along the coasts of Turkish Seas. Results are also useful for planning of fishery management of anchovies in Turkey.

  20. Ege İhracatçılar Birliklerinde Servqual Ölçeği ile Hizmet Kalitesinin Ölçülmesi(Measurement of Service Quality in Aegean Exporter’s Union by Servqual Scale

    Directory of Open Access Journals (Sweden)

    Esin FİRUZAN

    2007-01-01

    Full Text Available This study is based on the firm chosen from Aegean Exporter’s Union which is one of the 12 exporter’s union united under general secretariat in Turkey. Aim of the paper is to evaluate the survey designed by the service quality criteria. This survey is supposed to measure the needs and expectations of firms is satisfied by general secretariat. The service quality (fifth blank and blanks within fifth blank have been measured by servqual scale in Aegean Exporter’s Union. Questions have been combined under different criteria’s through factor analysis.After evaluating the data statistically, the results reported to the Aegean Exporter's union and the firms with in this to make them to serve with higher quality.

  1. Ecosystem Structure Changes in the Turkish Seas as a Response to Overfishing

    Science.gov (United States)

    Gazihan Akoglu, Ayse; Salihoglu, Baris; Akoglu, Ekin; Kideys, Ahmet E.

    2013-04-01

    Human population in Turkey has grown more than five-fold since its establishment in 1923 and more than 73 million people are currently living in the country. Turkey is surrounded by partially connected seas (the Black Sea, the Sea of Marmara, the Aegean Sea and the Mediterranean Sea) each of which has significantly different productivity levels and ecosystem characteristics. Increasing human population with its growing socio-economic needs has generated an intensive fishing pressure on the fish stocks in its exclusive economic zone. Fishing grounds in the surrounding seas were exploited with different fishing intensities depending upon their productivity level and catch rates. Hence, the responses of these different ecosystems to overfishing have been realized differently. In this study, changes of the ecosystem structures in the Turkish Seas were comparatively investigated by ecosystem indices such as Marine Trophic Index (MTI), Fishing in Balance (FiB) and Primary Production Required (PPR) to assess the degree of sustainability of the fish stocks for future generations.

  2. U-Pb zircon geochronology of the Paleogene - Neogene volcanism in the NW Anatolia: Its implications for the Late Mesozoic-Cenozoic geodynamic evolution of the Aegean

    Science.gov (United States)

    Ersoy, E. Yalçın; Akal, Cüneyt; Genç, Ş. Can; Candan, Osman; Palmer, Martin R.; Prelević, Dejan; Uysal, İbrahim; Mertz-Kraus, Regina

    2017-10-01

    The northern Aegean region was shaped by subduction, obduction, collision, and post-collisional extension processes. Two areas in this region, the Rhodope-Thrace-Biga Peninsula to the west and Armutlu-Almacık-Nallıhan (the Central Sakarya) to the east, are characterized by extensive Eocene to Miocene post-collisional magmatic associations. We suggest that comparison of the Cenozoic magmatic events of these two regions may provide insights into the Late Mesozoic to Cenozoic tectonic evolution of the Aegean. With this aim, we present an improved Cenozoic stratigraphy of the Biga Peninsula derived from a new comprehensive set of U-Pb zircon age data obtained from the Eocene to Miocene volcanic units in the region. The compiled radiometric age data show that calc-alkaline volcanic activity occurred at 43-15 Ma in the Biga Peninsula, 43-17 Ma in the Rhodope and Thrace regions, and 53-38 Ma in the Armutlu-Almacık-Nallıhan region, which are slightly overlapping. We discuss the possible cause for the distinct Cenozoic geodynamic evolution of the eastern and western parts of the region, and propose that the Rhodope, Thrace and Biga regions in the north Aegean share the same Late Mesozoic to Cenozoic geodynamic evolution, which is consistent with continuous subduction, crustal accretion, southwestward trench migration and accompanying extension; all preceded by the Late Cretaceous - Paleocene collision along the Vardar suture zone. In contrast, the Armutlu-Almacık-Nallıhan region was shaped by slab break-off and related processes following the Late Cretaceous - Paleocene collision along the İzmir-Ankara suture zone. The eastern and western parts of the region are presently separated by a northeast-southwest trending transfer zone that was likely originally present as a transform fault in the subducted Tethys oceanic crust, and demonstrates that the regional geodynamic evolution can be strongly influenced by the geographical distribution of geologic features on the

  3. {sup 137}Cs baseline levels in the Mediterranean and Black Sea: A cross-basin survey of the CIESM Mediterranean Mussel Watch programme

    Energy Technology Data Exchange (ETDEWEB)

    Thebault, Herve [IRSN, LERCM, Centre Ifremer, BP 330, F-83507 La Seyne sur Mer (France); Rodriguez y Baena, Alessia M. [International Commission for the Scientific Exploration of the Mediterranean Sea (CIESM), 16 Blvd de Suisse, MC-98000 Principality of Monaco (Monaco); Andral, Bruno [Ifremer, BP 330, F-83507 La Seyne sur Mer (France); Barisic, Delko [Center for Marine and Environmental Research, Lab. for Trace Physical Chemistry, Ruder Boskovic Inst., P.O. Box 1016, Bijenicka 54, 10002 Zagreb (Croatia); Albaladejo, Jose Benedicto [Inst. Espanol de Oceanografi' a (IEO), Centro Oceanografico de Murcia - Calle Varadero No. 1, 30740 San Pedro del Pinatar (Spain); Bologa, Alexandru S. [National Institute for Marine Research and Development ' Grigore Antipa' , RO-900581, Constantza (Romania); Boudjenoun, Redouane [Commissariat a l' Energie Atomique (COMENA), Centre de Radioprotection Recherche Nucleaire d' Algeret de Surete, Lab. d' Etudes d' Impact Radiologique, 2 Blvd F. Fanon - BP 399 Alger-Gare, 16000 Alger (Algeria); Delfanti, Roberta [Ente per le Nuove Tecnologie, l' Energia, e l' Ambiente (ENEA), Marine Environment Research Centre, La Spezia (Italy); Egorov, Victor N. [Inst. of Biology of the Southern Seas (IBSS), National Academy of Sciences of the Ukraine, 2 Porspekt Nakhimova, 99 011 Sevastopol, Crimea (Ukraine); El Khoukhi, Tahar [Centre d' Etudes Nucleaires de la Maamora (CNESTEN), BP 1382 RP Rabat 10001 (Morocco); Florou, Heleni [National Centre for Scientific Research ' Demokritos' , Aghia Paraskevi 153 10, P.O. Box 60228, Athens (Greece); Kniewald, Goran [Center for Marine and Environmental Research, Lab. for Trace Physical Chemistry, Ruder Boskovic Inst., P.O. Box 1016, Bijenicka 54, 10002 Zagreb (Croatia); Noureddine, Abdelkader [Commissariat a l' Energie Atomique (COMENA), Centre de Radioprotection Recherche Nucleaire d' Algeret de Surete, Lab. d' Etudes d' Impact Radiologique, 2 Blvd F. Fanon - BP 399 Alger-Gare, 16000 Alger (Algeria)] (and others)

    2008-07-01

    The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify {sup 137}Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured {sup 137}Cs levels were found to be very low (usually <1 Bq kg{sup -1} wet wt) {sup 137}Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.

  4. Seasonal patterns of wind-induced upwelling/downwelling in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Andrew Bakun

    2001-09-01

    Full Text Available The historical file of wind observations from maritime weather reports is summarized to identify the characteristic seasonal distributions of wind-induced Ekman upwelling and downwelling in the Mediterranean Sea. Both coastal upwelling/downwelling and wind-stress curl-driven open ocean upwelling/downwelling are treated in a unified description. Vigorous upwelling zones are found in the eastern Aegean Sea, off the west coast of Greece, and in the Gulf of Lyons. The southern coast of the Mediterranean is found to be primarily a downwelling area, although significant coastal upwelling does appear in the Gulf of Sidra during the spring and summer seasons, and along the Algerian coast during summer.

  5. Tracing organic and inorganic pollution sources of soils and water resources in Güzelhisar Basin of Aegean Region, Turkey

    Science.gov (United States)

    Czarnecki, Sezin; Colak Esetlili, Bihter; Esetlili, Tolga; Tepecik, Mahmut; Kurucu, Yusuf; Anac, Dilek; Düring, Rolf-Alexander

    2017-04-01

    This study was carried out to determine the residue level of major concern organic and inorganic pollutants in Güzelhisar Basin of Aegean Region in Turkey which represents a rather industrialized area having five large iron and steel mills, but also areas of agriculture. Soil samples were collected from GPS determined points at 0-30 and 30-60 cm depth of a grid system of 2.5 km to the east and 2.5 km to the west of the Güzelhisar stream. The area was grouped into three main areas as West, Middle, and East region. Water and sediment samples were collected from the Güzelhisar stream and from Güzelhisar dam every 30 kilometers which is already contaminated due to industrial facilities in Aliaga, is used to irrigate the agricultural land. Soil pH of the research area was determined within the range from 5.87 to 6.61. Topsoil contamination was examined for all investigated elements with the exception of Cd. An increase in pseudo total metal contents of Cr, Cu, Mn, Ni, and Zn was observed with increasing distance from the coast with a simultaneous decrease in pH. Due to the analysis of the organic pollutants, a continuous load with the herbicide trifluralin was determined with a few clearly raised points to a possible load of the stream water. Although HCH-Isomers were not found, DDT (DDT and transformation products) residues were ascertained in the soil samples. With regard to the analysis of the water samples of the Güzelhisar stream and dam, a background load with trifluralin was found which is to be explained with transport processes with regard to utilization of trifluralin in the agricultural areas.

  6. Brucellosis as a cause of fever of unknown origin in children admitted to a tertiary hospital in the Aegean region of Turkey.

    Science.gov (United States)

    Ciftdoğan, Dilek Yilmaz; Bayram, Nuri; Vardar, Fadil

    2011-08-01

    The aim of the study was to determine the role of brucellosis in children with fever of unknown origin (FUO) in the Aegean region of Turkey. For this purpose, the records of all children referred or admitted with diagnosis of FUO to the Department of Pediatric Infectious Diseases, Ege University Medical School, between 2003 and 2008 were scanned and 92 cases were identified retrospectively. Fifty-eight of these 92 children (63%) were diagnosed with infectious diseases, brucellosis being the most frequent cause (15.2%). Although several other infectious diseases do appear as a cause of FUO, brucellosis should be particularly considered as a differential diagnosis.

  7. The Sea Peoples, from cuneiform tablets to carbon dating.

    Directory of Open Access Journals (Sweden)

    David Kaniewski

    Full Text Available The 13(th century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192-1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations.

  8. Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    C. Parinos

    2013-09-01

    Full Text Available Surface sediments collected from deep basins (1018–4087 m depth of the eastern Mediterranean Sea (Ionian Sea, southern Aegean Sea and northwestern Levantine Sea were analyzed for aliphatic and polycyclic aromatic hydrocarbons as tracers of natural and anthropogenic inputs. Concentrations of total aliphatic hydrocarbons, n-alkanes and the unresolved complex mixture (UCM of aliphatic hydrocarbons varied significantly, ranging from 1.34 to 49.2 μg g−1, 145 to 4810 ng g−1 and 0.73 to 36.7 μg g−1, respectively, while concentrations of total polycyclic aromatic hydrocarbons (PAHs ranged between 11.6 and 223 ng g−1. Molecular profiles of determined hydrocarbons reflect a mixed contribution from both natural and anthropogenic sources in deep-sea sediments of the eastern Mediterranean Sea, i.e., terrestrial plant waxes, degraded petroleum products, unburned fossil fuels and combustion of grass, wood and coal. Hydrocarbon mixtures display significant variability amongst sub-regions, reflecting differences in the relative importance of inputs from various sources and phase associations/transport pathways of individual hydrocarbons that impact on their overall distribution and fate. Hydrocarbon concentrations correlated significantly with the organic carbon content of sediments, indicating that the latter exerts an important control on their transport and ultimate accumulation in deep basins. Additionally, water masses' circulation characteristics also seem to influence the regional features and distribution patterns of hydrocarbons. Our findings highlight the role of deep basins/canyons as repositories of both natural and anthropogenic chemical species.

  9. Modelling tsunamis in the Eastern Mediterranean Sea. Application to the Minoan Santorini tsunami sequence as a potential scenario for the biblical Exodus

    Science.gov (United States)

    Periáñez, R.; Abril, J. M.

    2014-11-01

    A numerical model which simulates the propagation of tsunamis in the Eastern Mediterranean has been developed. Several tsunami sources have been considered: earthquakes associated to geological faults, submarine landslides, entry of pyroclastic flows into the sea and the collapse of a volcano caldera. The model has been applied to different past events for which historic data or previous simulations exist, to test its performance. Then it has been applied to simulate tsunamis triggered by the explosion of Santorini volcano (17th century BC) in the Aegean Sea. While the model accounts for run-ups in the Aegean coasts, it fails to explain the isochronous tsunamigenic deposits reported in eastern Sicily and the levantine coasts. A scenario of a sequence of intense tectonics strain release triggering a series of tsunamis could better fit the whole dataset. Thus, a submarine landslide at the Gulf of Sirte may explain the Augias megaturbidite and the sedimentary deposits reported in Augusta Bay (Sicily). Similarly, a sequential tsunami in the eastern Nile Delta may explain the tsunamigenic deposits found in Israel and Gaza. Considering the former coastline at 3500 years BP, it could also provide a plausible scenario for the biblical sea crossing related in the Exodus.

  10. Abyssal and deep circulation in the Eastern Mediterranean Sea (Ionian Sea)

    Science.gov (United States)

    Artale, Vincenzo; Bensi, Manuel; Falcini, Federico; Marullo, Salvatore; Rubino, Angelo

    2016-04-01

    In the mid-1990s, experimental evidences on the Eastern Mediterranean Transient (EMT) were presented and it was shown that the Mediterranean abyssal circulation is not in a steady state but can be subjected to episodic sudden changes (Roether et al., 1996). In the last 10 years the Ionian Sea, the central and deepest part of the Mediterranean Sea, was subjected to relevant scientific interests from a theoretical and experimental point of view. Among these, there is the discovery of the BiOS (Bimodal Oscillating System), one new mechanism that drives a periodic (almost decadal) redistribution of surface and subsurface waters in the Eastern Mediterranean, with considerable feedbacks in the variability of the deep-water formation both in the southern Adriatic and in the Levantine and Aegean sub-basins (Gačić et al., 2010). In the Ionian Sea, numerous recent observational campaigns have been conducted to investigate the behaviour of deep and abyssal waters, at depths between 2000-4000m that are comparable to the mean global ocean depth (Rubino and Hainbucher, 2007; Bensi et al., 2013). There, advection, diffusion and vertical stability of the water masses can assume an important role on the internal quasi-periodical variability, creating the preconditions for catastrophic events such as the EMT or reversals of the Ionian circulation (Pisacane et al., 2006). Since there are no significant deep heat sources in the world ocean, waters that fill the deep ocean can only return to the sea surface as a result of downward mixing of heat from the sea surface to the bottom and vice versa and this occurs through eddy diffusion. Along our presentation, mainly through the analysis of the deepest CTD casts taken from 2009 to 2011 in the eastern basins and in particular in the Ionian Sea, we will show a significant change in the deep thermohaline structure (including its biogeochemical and hydrological characteristics), giving an indication on the time scale of the renewal of deep

  11. Scenario based tsunami wave height estimation towards hazard evaluation for the Hellenic coastline and examples of extreme inundation zones in South Aegean

    Science.gov (United States)

    Melis, Nikolaos S.; Barberopoulou, Aggeliki; Frentzos, Elias; Krassanakis, Vassilios

    2016-04-01

    A scenario based methodology for tsunami hazard assessment is used, by incorporating earthquake sources with the potential to produce extreme tsunamis (measured through their capacity to cause maximum wave height and inundation extent). In the present study we follow a two phase approach. In the first phase, existing earthquake hazard zoning in the greater Aegean region is used to derive representative maximum expected earthquake magnitude events, with realistic seismotectonic source characteristics, and of greatest tsunamigenic potential within each zone. By stacking the scenario produced maximum wave heights a global maximum map is constructed for the entire Hellenic coastline, corresponding to all expected extreme offshore earthquake sources. Further evaluation of the produced coastline categories based on the maximum expected wave heights emphasizes the tsunami hazard in selected coastal zones with important functions (i.e. touristic crowded zones, industrial zones, airports, power plants etc). Owing to its proximity to the Hellenic Arc, many urban centres and being a popular tourist destination, Crete Island and the South Aegean region are given a top priority to define extreme inundation zoning. In the second phase, a set of four large coastal cities (Kalamata, Chania, Heraklion and Rethymno), important for tsunami hazard, due i.e. to the crowded beaches during the summer season or industrial facilities, are explored towards preparedness and resilience for tsunami hazard in Greece. To simulate tsunamis in the Aegean region (generation, propagation and runup) the MOST - ComMIT NOAA code was used. High resolution DEMs for bathymetry and topography were joined via an interface, specifically developed for the inundation maps in this study and with similar products in mind. For the examples explored in the present study, we used 5m resolution for the topography and 30m resolution for the bathymetry, respectively. Although this study can be considered as

  12. Meiofauna, microflora and geochemical properties of the late quaternary (Holocene) core sediments in the Gulf of Izmir (Eastern Aegean Sea, Turkey)

    Science.gov (United States)

    Yümün, Zeki Ü.; Meriç, Engin; Avşar, Niyazi; Nazik, Atike; Barut, İpek F.; Yokeş, Baki; Sagular, Enis K.; Yildiz, Ayşegül; Eryilmaz, Mustafa; Kam, Erol; Başsari, Asiye; Sonuvar, Bora; Dinçer, Feyza; Baykal, Kubilay; Kaya, Seyhan

    2016-12-01

    The Gulf of Izmir has seen the construction of marinas at four locations; Karşıyaka, Bayraklı, İnciraltı and Urla (Çeşmealtı). Six drilling holes have been structured for each location. Morphological abnormities observed in foraminifer tests, obtained from these core drillings, and coloring encountered in both foraminifer tests and ostracod carapeces, provide evidence of natural and unnatural environmental pollution. The objectives of this study are to identify micro and macro fauna, foraminifers in particular, contained within sediments in the above-mentioned locations; to investigate the background of pollution in the Gulf Region; and to determine pollution's impact upon benthic foraminifer and ostracods. Çeşmealtı foraminifera tests did not lead to color and morphological changes. But foraminifera tests samples collected from Karşıyaka, Bayraklı and İnciraltı led them to turn black (Plate 4-6). However, concentrations of heavy metals (Ni, Cr and Mn) obtained from the sediments of Karşıyaka, Bayraklı and İnciraltı locations are higher than those obtained from the Çeşmealtı samples and high concentrations of these elements may be the cause of the color change in the samples during the foraminifera tests. In Karşıyaka and Bayraklı ostracod samples, Bosquetina carinella, Pterygocythereis jonesi, Semicytherura species; in the Çeşmealtı/Urla zone, Cyprideis torosa; in İnciraltı, Pseudopsammocythere reniformis; and in four zones, Loxoconcha and Xestoleberis species were observed in the range of relative frequency. The same analyses were done on nannoplankton but they did not lead to color and morphological changes.

  13. Shallow seismic study of the geothermal areas in the Gülbahçe Bay and İzmir Gulf (Aegean Sea, Western Turkey)

    Science.gov (United States)

    Altan, Zehra; Ocakoğlu, Neslihan

    2016-12-01

    The two seismic units, i.e., the basement and the basin sediments are interpreted as Miocene and Plio-Quaternary deposits, respectively. The basin sediments of approximately 255 m thickness are risen and compressed through the active strike-slip faults, GF1-GF3 extending in N-S direction towards the outer Gülbahçe Bay. These compressed sediments are interpreted as upwelling zones with weak reflection character and internal frequency attenuation. The most significant one is marked as a possible mud diaper zone with a 320 m width and the approximately 500 m. A synthetic model of the field data gathered from the diaper indicates that the top of the diapir is characterised by a strong positive reflection character while the internal diaper is represented by polarity reversals and weak reflections due to a velocity decrease with depth. Moreover, phase changes are observed at the border of the diapiric structure. A relatively thicker basin sediment unit of approximately 700 m was observed on the pro-delta sediments of the Gediz River and the sediments below in the İzmir Gulf. The active strike-slip faults, İF1-İF5 deform the basement and basin deposits. Moreover, two active normal faults, İF6 and İF7 are marked from inner to outer part of the gulf. The seismic attribute sections indicate weak reflection zones and frequency attenuation particularly both inside the pro-delta sediments and the sediments below. Observations suggest to us the existence of possible fluid and/or gas discharges and saturations in the Gülbahçe Bay and İzmir Gulf.

  14. Workshop on Compound Semiconductor Devices and Integrated Circuits held in Europe (24th) on May 29 - Jun 2, 2000 in Aegean Sea, Greece

    Science.gov (United States)

    2000-06-02

    Condensed Matter Sciences 35, 327-396 (1992). 9. A. Matulionis et al.. Phys. Stat. Solidi (b) 204. 453— 455 (1997). 10. V. Aninkevicius et al., Solid State...acknowledge Nichia Chemical Industries, Tokushima, for providing us their material. This work was financially supported by the Swiss National Science

  15. Shallow seismic study of the geothermal areas in the Gülbahçe Bay and İzmir Gulf (Aegean Sea, Western Turkey)

    Science.gov (United States)

    Altan, Zehra; Ocakoǧlu, Neslihan

    2016-09-01

    The two seismic units, i.e., the basement and the basin sediments are interpreted as Miocene and Plio-Quaternary deposits, respectively. The basin sediments of approximately 255 m thickness are risen and compressed through the active strike-slip faults, GF1-GF3 extending in N-S direction towards the outer Gülbahçe Bay. These compressed sediments are interpreted as upwelling zones with weak reflection character and internal frequency attenuation. The most significant one is marked as a possible mud diaper zone with a ~320 m width and the approximately 500 m. A synthetic model of the field data gathered from the diaper indicates that the top of the diapir is characterised by a strong positive reflection character while the internal diaper is represented by polarity reversals and weak reflections due to a velocity decrease with depth. Moreover, phase changes are observed at the border of the diapiric structure. A relatively thicker basin sediment unit of approximately 700 m was observed on the pro-delta sediments of the Gediz River and the sediments below in the İzmir Gulf. The active strike-slip faults, İF1-İF5 deform the basement and basin deposits. Moreover, two active normal faults, İF6 and İF7 are marked from inner to outer part of the gulf. The seismic attribute sections indicate weak reflection zones and frequency attenuation particularly both inside the pro-delta sediments and the sediments below. Observations suggest to us the existence of possible fluid and/or gas discharges and saturations in the Gülbahçe Bay and İzmir Gulf.

  16. Sea Legs

    Science.gov (United States)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  17. Offshore Seismic Observation in the Western Marmara Sea, Turkey

    Science.gov (United States)

    Yamamoto, Y.; Takahashi, N.; Citak, S.; Kalafat, D.; Pinar, A.; Gurbuz, C.; Kaneda, Y.

    2014-12-01

    The North Anatolian Fault (NAF) extends 1600 km westward from a junction with the East Anatolian Fault at the Karliova Triple Junction in eastern Turkey, across northern Turkey and into the Aegean Sea, accommodating about 25 mm/yr of right-lateral motion between Anatolia and the Eurasian plate. Since 1939, devastating earthquakes with magnitude greater than seven ruptured NAF westward, starting from 1939 Erzincan at the eastern Turkey and including the latest 1999 Izmit-Golcuk and the Duzce earthquakes in the Marmara region. Considering the fault segments ruptured by the May 24th, 2014 Northern Aegean earthquake, the only un-ruptured segments left behind NAF locate beneath the Marmara Sea and those segments keep their mystery due to their underwater location. To clarify the detailed fault geometry beneath the western Marmara Sea, we started to operate a series of ocean bottom seismographic (OBS) observations. As a first step, we deployed 3 pop-up type OBSs on 20th of March 2014 as a trial observation, and recovered them on 18thof June 2014. Although one of the OBSs worked only 6 days from the start of the observation, other two OBSs functioned properly during the whole 3-month observation period. Only 8 earthquakes were reported near the OBS network in 3 months periods according to the Kandilli Observatory and Earthquake Research Institute catalogue. Thus, we first searched for the microearthquakes missing by the land seismic network and estimated their precious location by using the initial 6 days data. We could identify about 50 earthquakes with more than 5 picking data of P and S first arrivals, and half of them located near the NAF. We also tested the hypocenter relocation by combining the land and OBS seismic data for the 8 earthquakes, and found that these earthquakes are located in between 12-24 km depths. Next, we are planning to deploy 10 OBSs from September 2014 to June 2015 as a second step for our observation. At the AGU fall meeting, we will be able to

  18. P, T, X magma storage conditions of the dominantly silicic explosive eruptions from Santorini volcano (Aegean Arc, Greece)

    Science.gov (United States)

    Cadoux, A.; Druitt, T. H.; Deloule, E.; Scaillet, B.

    2010-12-01

    It has been increasingly recognized that dramatic changes in magma storage conditions can occur over very short periods of time at a single volcano and might be in close relationships with stress variations imposed on the crustal plumbing by the overlying volcano as it changes shape and volume over time. The Santorini volcano (South Aegean Arc) is an ideal target to unravel these potential relationships as its history is marked by alternating episodes of edifice construction and caldera collapses and the chronostratigraphy is well constrained. We focused our study on the products of the four major, dominantly silicic, explosive eruptions of Santorini: the Lower Pumice 1 and 2 (200 to 180 ka; 1st explosive cycle) and, the Cape Riva and the Minoan (~ 21 to 3 ka, 2nd explosive cycle). In order to precisely define the P, T, fO2, X (X for volatiles) storage conditions of the silicic magmas prior to these eruptions, we carried out a detailed micro-petrological and geochemical study on natural samples combined with an experimental work. The selected silicic components of the four eruptions are dacite to rhyodacite (SiO2 = 67-70 wt.%) with similar mineral paragenesis (plagioclase, orthopyroxene, clinopyroxene, ilmenite, magnetite, apatite ± pyrrhotite) and crystallinity < 20%. High resolution BSE images of plagioclase and pyroxene phenocrysts and EMPA profiles reveal a complex crystallization history. Plagioclases display fine-scale oscillatory normal zoning, resorbtion zones where melt inclusions (MI) of rhyolitic compositions were trapped, and An-rich sieved cores. Clinopyroxenes also show zoning patterns and include rhyolitic MI. Both interstitial glass and MI are Cl-rich (~3000 ppm) while F and S are less abundant (F ≤ 700 ppm, S ≤ 100 ppm). Determination of H2O contents by SIMS is in progress at the CRPG-Nancy (previous measurements from the literature gave ~ 5 wt.% H2O in the Minoan rhyodacite and ~4 wt.% in the Lower Pumice 2). Ilmenite-magnetite geothermometry

  19. Multispecies fisheries management in the Mediterranean Sea: application of the Fcube methodology

    DEFF Research Database (Denmark)

    Maravelias, C.D.; Damalas, D.; Ulrich, Clara

    2012-01-01

    and socioeconomic parameters were used for coastal and trawl fisheries in the Aegean Sea. Results pointed out the strengths and weaknesses of alternative management strategies from both a biological and socioeconomic perspective. Fcube revealed the importance of effort control in the coastal fisheries......The ecosystem approach (EA) advocates that advice should be given based on a holistic management of the entire marine ecosystem and all fisheries and fleets involved. Recent developments have advanced to multi‐species, multi‐fisheries advice, rather than on a single‐species/fleet/area stock basis......, bridging the gap between existing single‐species approaches and the needs of the EA. The Fleet and Fisheries Forecast method (Fcube) method estimates potential levels of effort by fleet in mixed fisheries situations to achieve specific targets of fishing mortality. Data on effort, landings...

  20. Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea

    KAUST Repository

    Tsangaris, Catherine

    2015-09-23

    Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the “Integrated Biological Responses version 2” index was useful for the interpretation of overall biomarker responses.

  1. Biochemical biomarker responses to pollution in selected sentinel organisms across the Eastern Mediterranean and the Black Sea.

    Science.gov (United States)

    Catherine, Tsangaris; Vanessa, Moschino; Evangelia, Strogyloudi; Valentina, Coatu; Andreja, Ramšak; Rana, Abu Alhaija; Susana, Carvalho; Serena, Felline; Alisa, Kosyan; Yiota, Lazarou; Ioannis, Hatzianestis; Andra, Oros; Daniela, Tiganus

    2016-01-01

    Pollution effects were assessed by means of biochemical biomarkers (catalase, glutathione S-transferase and acetylcholinesterase activities, and metallothioneins content) in five species at selected coastal sites across the Eastern Mediterranean and the Black Sea. The mussel Mytilus galloprovincialis, a well-established sentinel species, was investigated in the Adriatic Sea, Aegean Sea, and Black Sea. The mussel Brachidontes pharaonis and the striped red mullet Mullus surmuletus were used in the Levantine Sea where M. galloprovincialis is not present. The white seabream Diplodus sargus sargus and the gastropod Rapana venosa were additionally sampled in the Adriatic and the Black Sea, respectively. Mussels showed catalase, glutathione S-transferase, and acetylcholinesterase responses to pollution in most geographical areas while the response of metallothioneins was restricted to a few sites. R. venosa showed marked responses of catalase and metallothioneins whereas both fish species did not generally exhibit variations in biomarker values among sites. The approach based on the reference deviation concept using the "Integrated Biological Responses version 2" index was useful for the interpretation of overall biomarker responses.

  2. Sea Ice

    Science.gov (United States)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  3. Sea level change

    Digital Repository Service at National Institute of Oceanography (India)

    Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

    This chapter considers changes in global mean sea level, regional sea level, sea level extremes, and waves. Confidence in projections of global mean sea level rise has increased since the Fourth Assessment Report (AR4) because of the improved...

  4. A 2-year intercomparison of the WAM-Cycle4 and the WAVEWATCH-III wave models implemented within the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. KORRES

    2012-12-01

    Full Text Available In this work we present the implementation of a wave forecast/hindcast system for the Mediterranean Sea at a 1/10º horizontal resolution and we show a first assessment of its performance by inter-comparing model results to observational data time series at selected points for the period 2000-2001. The system which is part of the POSEIDON-II operational system includes the WAM – Cycle4 and the WAVEWATCH-III wave forecast models (implemented within the same region one way coupled with the non-hydrostatic version of the ETA atmospheric model which provides at 3-hour intervals the necessary wind velocity fields to the wave models. The same system but based on the WAM-Cycle4 wave model, has been used in the past for the production of the Aegean Sea wind and wave Atlas. Overall, the inter-comparison shows that both wave models are rather skilful in predicting the integral wave parameters with significant wave height skill scores in the range 0.85-0.90 and mean period scores in the range 0.77-0.83. It is also evident that WAM model has a tendency to overestimate mean wave periods while the opposite is true for WAVEWATCH-III model. Differences between the two models simulated spectra exist along the main passage of cyclonic systems over the Mediterranean Sea while in the wind seas dominated areas of the basin (the Aegean Sea for example the two models show almost the same behavior.

  5. Poseidon: A marine environmental monitoring, forecasting and information system for the Greek seas

    Directory of Open Access Journals (Sweden)

    T.H. SOUKISSIAN

    2012-12-01

    Full Text Available The scope of this work is twofold: i to discuss and analyze some principles, issues and problems related to the development and advancement of Operational Oceanography in Greece and ii to present a real-time monitoring and forecasting system for the Aegean Sea, which is currently under implementation. Operational Oceanography in Greece has become a necessity today, since it can provide aid to find solutions on problems related to societal, economic, environmental and scientific issues. Most of the Greek coastal regions are under pressure, susceptible to damages due to the increasing tendency of the population to move from the inland to the coast, marine environmental pollution, competitive development of the coastal market sector, etc. Moreover, the complex geomorphology of the coastal areas and the interdependence between natural processes and human activities causes significant alterations in this delicate environment. A rational treatment of these problems can be based on integrated coastal zone management (ICZM. An absolutely necessary means for establishing ICZM is the operation of marine moni- toring systems. Such a system ("POSEIDON system" is under implementation by the National Centre for Marine Research. POSEIDON is a comprehensive marine monitoring and forecasting system, that aims to improve environmental surveillance and facilitate sea transport, rescue and safety of life at sea, fishing and aquaculture, protection of the marine ecosystem, etc. POSEIDON is expected to enhance considerably the capabilities to manage, protect and develop the marine resources of the Greek Seas and to promote Greek Operational Oceanography.

  6. Modeling nonstationary extreme wave heights in present and future climate of Greek Seas

    Directory of Open Access Journals (Sweden)

    Panagiota Galiatsatou

    2016-01-01

    Full Text Available In this study the generalized extreme value (GEV distribution function was used to assess nonstationarity in annual maximum wave heights for selected locations in the Greek Seas, both in the present and future climate. The available significant wave height data were divided into groups corresponding to the present period (1951 to 2000, a first future period (2001 to 2050, and a second future period (2051 to 2100. For each time period, the parameters of the GEV distribution were specified as functions of time-varying covariates and estimated using the conditional density network (CDN. For each location and selected time period, a total number of 29 linear and nonlinear models were fitted to the wave data, for a given combination of covariates. The covariates used in the GEV-CDN models consisted of wind fields resulting from the Regional Climate Model version 3 (RegCM3 developed by the International Center for Theoritical Physics (ICTP with a spatial resolution of 10 km × 10 km, after being processed using principal component analysis (PCA. The results obtained from the best fitted models in the present and future periods for each location were compared, revealing different patterns of relationships between wind components and extreme wave height quantiles in different parts of the Greek Seas and different periods. The analysis demonstrates an increase of extreme wave heights in the first future period as compared with the present period, causing a significant threat to Greek coastal areas in the North Aegean Sea and the Ionian Sea.

  7. Genetic divergence between the scad subspecies Trachurus Mediterraneus (Carangidae, pisces from the Black Sea and the Mediterranean

    Directory of Open Access Journals (Sweden)

    I.S. DOBROVOLOV

    2012-12-01

    Full Text Available Analysis of myogen and eleven enzymes (AAT, ADH, EST, GPI, IDHP, LDH, MDH, MEP, PGDH, PGM and SOD were carried out by using starch gel and isoelectric focusing electrophoresis on thinlayer and ultrathin polyacrylamide ampholine and servalite gels in scad species from the Black Sea, the Sea of Marmara, the Aegean Sea, and the Mediterranean. Data from electrophoretic investigations was used to clarify the population structure of the scad migrating in the Bulgarian aquatory of the Black Sea and consisting of two main subpopulations: a a "Black Sea" one hibernating in this sea only, and b a "Sea of Marmara" one hibernating in that sea and contiguous Black Sea regions around the Bosporus. Non-specific muscular esterases were used, because they were appropriate for identification of both subspecies: Trachurus mediterraneus ponticus Aleev and Tr.m.mediterraneus Steindachner. Nei's genetic distance (D=0,0113 was used as an indication of their isolation dated back to the Carangate Period. An attempt was made to check the hypothesis of the origin of "large" ("giant" scad in the Black Sea as a result of the heterozygotic interbreeding between Tr.m.ponticus Aleev and Tr.m.mediterraneus Steindachner. A new allele Est-1E as well as the previously known alleles Est-1A and Est-1-B, were found in Mediterranean scad Tr.m.mediterraneus caught off Nice (France. It's proposed that the presence of the large form of large scat in this area is also a consequence of the heterozytic efect from the interbreeding between a population marked by Est-1-A and Est-1-B and a population marked by Est-1-E, probably inhabiting the waters around Gibraltar in the Atlantic Ocean.

  8. Brachyopa minima (Diptera: Syrphidae), a new species from Greece with notes on the biodiversity and conservation of the genus Brachyopa Meigen in the Northern Aegean Islands.

    Science.gov (United States)

    Pérez-Bañón, Celeste; Radenković, Snezana; Vujić, Ante; Petanidou, Theodora

    2016-01-29

    An on-going study of the hoverfly fauna of the Northern Aegean Islands (Greece) has revealed the presence of four species of the genus Brachyopa Meigen. During the survey the following species were found: B. bicolor (Fallén), B. quadrimaculosa Thompson in Kaplan & Thompson, B. minima Vujić & Pérez-Bañón sp. nov. and an unidentified species very close to B. pilosa (Collin). Morphological characters and mitochondrial COI barcodes were used to link different life stages of B. minima, and to identify a larval specimen of B. bicolor. In this study adult and larval morphology and habitat preferences for B. minima are described. The description of larval morphology of B. bicolor and Brachyopa sp. aff. pilosa is amended too. An identification key to the adults of the B. quadrimaculosa group sensu Kassebeer (2002) in the Eastern Mediterranean (Greece, Israel and Turkey) is provided. The importance of specific microhabitats for the continued existence of these taxa is discussed.

  9. The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

    Science.gov (United States)

    Coll, Marta; Piroddi, Chiara; Steenbeek, Jeroen; Kaschner, Kristin; Ben Rais Lasram, Frida; Aguzzi, Jacopo; Ballesteros, Enric; Bianchi, Carlo Nike; Corbera, Jordi; Dailianis, Thanos; Danovaro, Roberto; Estrada, Marta; Froglia, Carlo; Galil, Bella S.; Gasol, Josep M.; Gertwagen, Ruthy; Gil, João; Guilhaumon, François; Kesner-Reyes, Kathleen; Kitsos, Miltiadis-Spyridon; Koukouras, Athanasios; Lampadariou, Nikolaos; Laxamana, Elijah; López-Fé de la Cuadra, Carlos M.; Lotze, Heike K.; Martin, Daniel; Mouillot, David; Oro, Daniel; Raicevich, Saša; Rius-Barile, Josephine; Saiz-Salinas, Jose Ignacio; San Vicente, Carles; Somot, Samuel; Templado, José; Turon, Xavier; Vafidis, Dimitris; Villanueva, Roger; Voultsiadou, Eleni

    2010-01-01

    Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well. This abstract has been translated to other languages (File S1). PMID:20689844

  10. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats.

    Directory of Open Access Journals (Sweden)

    Marta Coll

    , the Strait of Gibraltar and the adjacent Alboran Sea, western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well. This abstract has been translated to other languages (File S1.

  11. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  12. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  13. Spatial and seasonal variability of particulate matter optical and size properties in the Eastern Mediterranean Sea

    Science.gov (United States)

    Karageorgis, A. P.; Georgopoulos, D.; Kanellopoulos, T. D.; Mikkelsen, O. A.; Pagou, K.; Kontoyiannis, H.; Pavlidou, A.; Anagnostou, Ch.

    2012-12-01

    Particulate matter plays a paramount role in the biogeochemical processes taking place in the marine environment. We report seasonal (spring and summer 2008) distribution of particulate matter in the Eastern Mediterranean, along a transect extending from the open Ionian Sea to the North Aegean Sea, including measurements in the Levantine Sea. A suite of optical instruments measuring beam attenuation (beam cp), fluorescence and particle size, the latter obtained with the innovative in-situ laser particle sizer LISST-Deep are used in concert with traditional measurements of particulate matter concentration (PMC), and total chlorophyll α from bottle samples. PMCs were generally low during both seasons (range: 0.02-0.85 mg L- 1), with values substantially higher in the euphotic zone during spring. The deep waters (> 200 m) in the Eastern Mediterranean exhibit extremely low PMCs, well-below 0.1 mg L- 1. Total chlorophyll α concentrations ranged from 0.003 to 0.28 μg L- 1 in spring and from 0.08 to 0.19 μg L- 1 in summer, verifying the ultra-oligotrophic character of the area. A significant correlation of beam cp and fluorescence in spring suggests that sources of particles are primarily biogenic in the surface waters. Deep water formation triggered the development of a ~ 900-m thick benthic nepheloid layer in the N. Aegean Sea. LISST-Deep revealed valuable information on the particle volume concentrations and the median particle size. It is striking that large particles (range: 31-230 μm; median ~ 85 μm) predominate in the entire region, from the surface up to the deep waters. In addition, accumulation of particles in the pycnocline is observed during summer; however, it is possible that schlieren (increase in beam attenuation due to scattering off of density gradients) could be responsible for the high particle volume concentrations and large median particle diameters recorded. These measurements, conducted for the first time in the Eastern Mediterranean

  14. Stable carbon isotope gradients in benthic foraminifera as proxy for organic carbon fluxes in the Mediterranean Sea

    Science.gov (United States)

    Theodor, Marc; Schmiedl, Gerhard; Jorissen, Frans; Mackensen, Andreas

    2016-11-01

    We have determined stable carbon isotope ratios of epifaunal and shallow infaunal benthic foraminifera in the Mediterranean Sea to relate the inferred gradient of pore water δ13CDIC to varying trophic conditions. This is a prerequisite for developing this difference into a potential transfer function for organic matter flux rates. The data set is based on samples retrieved from a well-defined bathymetric range (400-1500 m water depth) of sub-basins in the western, central, and eastern Mediterranean Sea. Regional contrasts in organic matter fluxes and associated δ13CDIC of pore water are recorded by the δ13C difference (Δδ13CUmed-Epi) between the shallow infaunal Uvigerina mediterranea and epifaunal species (Planulina ariminensis, Cibicidoides pachydermus, Cibicides lobatulus). Within epifaunal taxa, the highest δ13C values are recorded for P. ariminensis, providing the best indicator for bottom water δ13CDIC. In contrast, C. pachydermus reveals minor pore water effects at the more eutrophic sites. Because of ontogenetic trends in the δ13C signal of U. mediterranea of up to 1.04 ‰, only tests larger than 600 µm were used for the development of the transfer function. The recorded differences in the δ13C values of U. mediterranea and epifaunal taxa (Δδ13CUmed-Epi) range from -0.46 to -2.13 ‰, with generally higher offsets at more eutrophic sites. The measured δ13C differences are related to site-specific differences in microhabitat, depth of the principal sedimentary redox boundary, and TOC content of the ambient sediment. The Δδ13CUmed-Epi values reveal a consistent relation to Corg fluxes estimated from satellite-derived surface water primary production in open-marine settings of the Alboran Sea, Mallorca Channel, Strait of Sicily, and southern Aegean Sea. In contrast, Δδ13CUmed-Epi values in areas affected by intense resuspension and riverine organic matter sources of the northern to central Aegean Sea and the canyon systems of the Gulf of Lion

  15. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Directory of Open Access Journals (Sweden)

    K. Sevastou

    2012-12-01

    Full Text Available The long held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and bacteria, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine spanning over 4 km in depth revealed a high diversity in terms of both metazoan meiofauna and microbial communities. The higher meiofaunal abundance and richness observed in the northern Aegean Sea highlights the effect of productivity on benthic patterns. Non parametric analyses detected no differences for meiobenthic standing stocks and major taxa diversity (α, β, γ and δ components between the two habitats (basin vs. slope for the whole investigated area and within each region, but revealed significant bathymetric trends: abundance and richness follow the well-known gradient of decreasing values with increasing depth, whereas differentiation diversity (β- and δ-diversity increases with depth. In spite of a similar bathymetric trend observed for nematode genera richness, no clear pattern was detected with regard to habitat type; the observed number of nematode genera suggests higher diversity in slopes, whereas richness estimator Jack1 found no differences between habitats. On the other hand, δ-diversity was higher at the basin habitat, but no differences were found among depth ranges, though turnover values were high in all pairwise comparisons of the different depth categories. Results of multivariate analysis are in line with the above findings, indicating high

  16. A biomarker study of high resolution sedimentary records in the eastern Mediterranean Sea since the last glacial maximum

    Science.gov (United States)

    Katsouras, G.; Gogou, A.; Bouloubassi, I.; Emeis, K.-C.; Triantaphyllou, M. V.; Lykousis, V.

    2009-04-01

    Information stored in sedimentary records provides evidence on climate and environmental variability at decadal to centennial time scales. The eastern Mediterranean Sea and the related Aegean Sea exhibit high sedimentation rates in certain areas and are considered as sensitive regions to record paleo-environmental and -climatic changes. The aim of our study is to reconstruct high-frequency paleoclimatic variations and identify associated changes in the physical, chemical and biological environment in selected basins of the eastern Mediterranean Sea, using molecular biogeochemical proxies. Here we present a high-resolution multi-proxy study along two Aegean Sea cores (north (152SL) and southeast (NS-14)) and a Libyan Sea core (HCM2/22). An important time marker and indicator of remarkable climatic and environmental changes is sapropel S1, a sediment layer rich in organic carbon. Depending on the water column depth, the sediment accumulation rates and the proximity to freshwater and water formation sources, S1 deposited between ~9.8 to 6.4 kyr BP, with an apparent interruption in the S1 deposition that occurred from ~8.6 to 7.6 kyr BP. SSTs based on alkenone unsaturation index Uḱ 37, ^15tot, ^13Corg and various marine and terrestrial biomarkers are used to investigate the region's climatic variability, and the modifications in the biogeochemical functioning of the eastern Mediterranean Sea. Uḱ 37 SST distribution in our records reveals significant fluctuations in temperature over the last 20.000 yrs. Organic carbon stable isotopes values span a narrow range over the whole sequence, with values varying to typical marine origin. The distributions of land-plant biomarkers are indicative of variable terrigenous organic matter supply and the concomitant transport of nutrients to surface waters. Furthermore, the distribution patterns and characteristic ratios of marine biomarkers exhibit differences in the paleoproductivity trends and ventilation changes over the last

  17. Indicators for the Sea-floor Integrity of the Hellenic Seas under the European Marine Strategy Framework Directive: establishing the thresholds and standards for Good Environmental Status

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

    Full Text Available A data set of 625 samples of benthic macroinvertebrates collected from the Hellenic Seas (Ionian and Aegean was used to establish thresholds and reference standards for two of the indicators addressing the descriptors of Sea-floor Integrity under the Marine Strategy Framework Directive (MSFD: species diversity and richness and the ratio of sensitive species to tolerant species. The dataset was categorised according to the baseline ecological status assessment of the respective water bodies under the Water Framework Directive (WFD. Species diversity and richness were characterised using the Shannon diversity and species richness indices, respectively, and were analysed for three pre-defined substrate types, three depth zones and three sample-size categories, and the significant categories were statistically validated. Good Environmental Status (GEnS threshold and reference values were established for the valid combinations of categories denoted as ‘ecotypes’ through the use of a boxplot and an analysis of variance. The limitations and specifications for an overall GEnS assessment using the above indices are highlighted based on the WFD experience. For the ratio of sensitive species to tolerant species, the BENTIX index classification scale is proposed for GEnS assessment, and an integrated approach to the assessment of diversity and species richness is suggested. Finally, the regionality of the tested indices in relation to the two Mediterranean sub-regions, including the Hellenic area, was tested.

  18. Tracing organic and inorganic pollution sources of agricultural crops and water resources in Güzelhisar Basin of the Aegean Region - Turkey

    Science.gov (United States)

    Czarnecki, Sezin; Colak Esetlili, Bihter; Esetlili, Tolga; Tepecik, Mahmut; Anac, Dilek; Düring, Rolf-Alexander

    2014-05-01

    The study area Güzelhisar Basin is 6 km far from the city Aliaga, Aegean Region in Turkey which represents a rather industrialized area having five large iron and steel factories, but also areas of agriculture. Steel industry in Aliaga is causing metal pollution. Around Güzelhisar Basin and nearby, the dominant crop fields are cotton, maize, vegetables, olive trees and vineyards. Güzelhisar stream and dam water is used for irrigation of the agricultural land. Due to contamination from metal industry in Aliaga, organic farming is not allowed in this region. Industrial activities in the region present a threat on sustainable agriculture. The region is a multi-impacted area in terms of several pollutant sources affecting soil and water quality. The overall objective of the project is to trace back plant nutrients (N, P, K, Ca, Mg, Na, Fe, Mn, Zn, Cu, and B), hazardous substances (i. e. persistent organic pollutants), radionuclides (40K, 232Th, 226Ra/238U), and metal contents (As, Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, and Zn) by examining the soils, agricultural crops and natural plants from Güzelhisar Basin and water and sediments from Güzelhisar stream and dam. Spatial distribution of pollution will be evaluated by regionalization methods. For this, an advanced analytical methodology will be applied which provides an understanding of sources and occurrence of the respective substances of concern. An innovative multi-tracer approach comprising organic and inorganic marker substances, will identify and quantitatively assess sources and their impact on water pollution and the pollutant pathways in this agricultural crop production system.

  19. Effect of terroir on the phenolic compounds of Muscat of Bornova Wines from 3 different sub-regions of Aegean, Turkey

    Directory of Open Access Journals (Sweden)

    Karaoğlan Selin N. Yabaci

    2015-01-01

    Full Text Available Characterization of the phenolic compounds of wines from Muscat of Bornova, a native aromatic white grape variety (Vitis vinifera grown in the Aegean region of Turkey and the influence of terroir (Menderes, Halilbeyli and Kemaliye sub- regions on these compounds were investigated. From Muscat of Bornova growing sub regions, Menderes/İzmir has a typical Mediterranean climate at around 90 m altitude which is located Eagean cost area with a fertile sandy-loamy soil; Halilbeyli/İzmir sub-region is located in inner İzmir, close to Manisa with 115 m altitude with same soil structure of Menderes. Kemaliye/Manisa has a transition climate between Mediterranean and continental climate at about 245 m altitude. Its soil is pale with a distinct amount of lime (∼30% and sandy-loamy, as well. High performance liquid chromatography-diode array dedector (HPLC-DAD and mass spectrometry (MS were used for the phenolic compounds analysis. Four flavanols, eight phenolic acids and a flavonol were identified and quantified. It was observed that the total phenolic content in the Halilbeyli sub-region was the highest, fol- lowed by the Menderes and Kemaliye sub-regions. Procyanidin B4 was the most abundant flavanol and quercetin-3-O-glucoside was the only flavonol identified in all regions’ wines. Sensory analysis was also used to investigate the influences of terroir. Statistically significant (0.05 regional differences were observed. Based upon sensory analysis, the wine obtained from Halilbeyli was darker in color, and had more astringency and bitterness than the others, and was the least popular wine. Kemaliye and Menderes were both preferred due to their better coloring, flavour, less astringency and bitterness attributes.

  20. Tales of some ancient harbors in the Aegean back-arc region: Earthquakes, coastal changes, historical impacts

    Science.gov (United States)

    Stiros, Stathis; Saltogianni, Vasso

    2017-04-01

    Tectonically active terrains are characterized by seismic transient ground motions (shaking) and by permanent ground motions in the vicinity of activated faults, with both effects occasionally leaving their signature on human constructions and the landscape. Especially in coastal areas marked by small tidal ranges and normal water salinity, as is the case with most parts of the Eastern Mediterranean, even small-amplitude tectonic motions can be derived from observations on coastal constructions, mainly harbors, but also on spring chambers in nearly arid environments, sewers, etc. Such observations, if coupled with well-dated observations of destructions and repairs and of changes in the occupation style of ancient sites can permit precious information conveyed from archaeology to tectonics/seismology and vice versa. A transect with harbor remains from Rhodes to the Gulf of Corinth and then till the Ionian Islands provides some excellent examples. The military harbor of Rhodes, in an area of long term uplift, a coded report of which seems to be provided by ancient poet Pindar, was subject to seismic subsidence and destruction, but with major international support, it was repaired, till renewed uplift brought it several meters above the water. In the Corinth area, the Kenchreai harbor was abruptly submerged during a major repair of a temple, as revealed by precious stained glass panels, ready to use but abandoned in shallow water beneath ruins, while radiometric dating of the uplift in the western Lechaion harbor, constrains its excavation in swampy environment not in Roman times, but to the period of flourishing of Corinth in circa 600BC and the colonization of Italy. Farther west, the sea-level mark of the harbor of Aigeira, at Mavra Litharia (Derveni/Akrata) indicates 4m uplift since the Roman period, at least partly seismic, correlating with an exposed reef and the abandonment of the repairs of the theatre of Aigeira. Seismic land uplift explains the demise of

  1. White sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, R.A. [Lomonosov Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics]|[Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.]|[Russian Academy of Sciences, Moscow (Russian Federation). Shirshov Inst. of Oceanology; Kalmykov, S.N.; Lisitzin, A.P. [Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.

    2004-07-01

    The aim of the present work is to estimate potential sources and chronology of pollution of the White Sea (Russia) by artificial radionuclides. White Sea is semi-closed water body connected with Barents Sea by a narrow strait. Thus, pollution of White Sea may be caused by highly polluted Barents waters and river (mainly Northern Dvina) run-off. This is the first detailed investigation of radioactivity of White Sea sediment records. (orig.)

  2. Bidirectional air-sea exchange and accumulation of POPs (PAHs, PCBs, OCPs and PBDEs) in the nocturnal marine boundary layer

    Science.gov (United States)

    Lammel, Gerhard; Meixner, Franz X.; Vrana, Branislav; Efstathiou, Christos I.; Kohoutek, Jiři; Kukučka, Petr; Mulder, Marie D.; Přibylová, Petra; Prokeš, Roman; Rusina, Tatsiana P.; Song, Guo-Zheng; Tsapakis, Manolis

    2016-05-01

    As a consequence of long-range transported pollution, air-sea exchange can become a major source of persistent organic pollutants in remote marine environments. The vertical gradients in the air were quantified for 14 species, i.e. four parent polycyclic aromatic hydrocarbons (PAHs), three polychlorinated biphenyls (PCBs), three organochlorine pesticides (OCPs) and two polybrominated diphenylethers (PBDEs) in the gas-phase at a remote coastal site in the southern Aegean Sea in summer. Most vertical gradients were positive (Δc/Δz > 0), indicating downward (net depositional) flux. Significant upward (net volatilisational) fluxes were found for three PAHs, mostly during daytime, and for two OCPs, mostly during night-time, as well as for one PCB and one PBDE during part of the measurements. While phenanthrene was deposited, fluoranthene (FLT) and pyrene (PYR) seem to undergo flux oscillation, hereby not following a day-night cycle. Box modelling confirms that volatilisation from the sea surface has significantly contributed to the night-time maxima of OCPs. Fluxes were quantified based on eddy covariance. Deposition fluxes ranged from -28.5 to +1.8 µg m-2 day-1 for PAHs and -3.4 to +0.9 µg m-2 day-1 for halogenated compounds. Dry particle deposition of FLT and PYR did not contribute significantly to the vertical flux.

  3. Morphological recognition of Globigerinoides ruber morphotypes and their susceptibility to diagenetic alteration in the eastern Mediterranean Sea

    Science.gov (United States)

    Kontakiotis, G.; Antonarakou, A.; Mortyn, P. G.; Drinia, H.; Anastasakis, G.; Zarkogiannis, S.; Möbius, J.

    2017-10-01

    Planktonic foraminiferal geochemistry presents a valuable archive for paleoceanographic reconstructions. However in high salinity and carbonate super-saturated settings, precipitation of inorganic calcite onto foraminiferal tests can potentially alter the primary geochemical signal, biasing Mg/Ca ratios and ensuing paleoceanographic reconstructions. Here we utilize test biometrics (specifically related to the compression and elongation of the last chambers) to identify four distinct morphotypes (labelled A-D) of the paleoceanographically important planktonic foraminifer species Globigerinoides ruber, and further evaluate their susceptibility to diagenetic alteration from a suite of surface sediments in the eastern Mediterranean Sea. The three distinguished morphotypes (A-C) correspond to previously recognized morphotypes (;Normal;, ;Platys;, ;Elongate; respectively) in the Mediterranean Sea, while the remaining (D or ;Twin;) was designated for the first time. We also compare Scanning Electron Microscopy (SEM) observations performed on four distinguished morphotypes, indicative of potential diagenetic alteration influence. We identified 3 different overgrowth stages (OGA1-OGA3), as a function of geography in the study area. The early diagenesis degrees (involving all the morphotypes) are only geographically distinct along the eastern Mediterranean (increasing to the south), since the morphology does not play a role in the likelihood of diagenetic alteration. Particularly, in the north Aegean Sea, SEM analyses reveal the absence or limited presence of an overgrowth imprint in all recognized morphotypes, while in the central-south Aegean and Levantine Seas they show higher amplitudes of diagenetic overprint supporting the general trend to advanced diagenetic alteration. The semi-enclosed oligotrophic nature and high salinity of this setting, in combination with the different degree of carbonate precipitation and calcite super-saturation between the sub-basins, could

  4. The pre-Kos Plateau Tuff Volcanic Rocks on Kefalos Peninsula (Kos Island, Dodecanese, Greece): Crescendo to the Largest Eruption of the Modern Aegean Arc

    Science.gov (United States)

    Bachmann, O.; Schnyder, C.

    2006-12-01

    Young volcanic rocks (K-Ar ages of 3 to 0.5 Ma) from the Kefalos Peninsula (Kos Island, Dodecanese, Greece) erupted prior to the voluminous (>60 km\\ 3) Kos Plateau Tuff (KPT; Ar-Ar age of 0.16 Ma) were studied in order to better define the conditions that led to the paroxysmal eruption of the modern Aegean Arc. Two different whole-rock compositions were sampled on Kefalos peninsula; dacites (63-65 wt% SiO2) and rhyolites (75-77 wt% SiO2). Kefalos dacites are crystal-rich (>40% crystals), show high Sr-Ba contents compared to other continental arcs, and have "adakitic" Sr/Y ratios (>40). Kefalos rhyolites are typical high- SiO2 arc magmas, similar in composition and mineralogy to the KPT, but displaying lower crystallinities (30% in most of the KPT). The high Sr/Y ratios of the dacites is surprising in an area where the subducting slab is not particularly hot and the continental crust relatively thin (~30 km). If the low Y and high Sr-Ba contents result from the fact that magma formed deep enough to supress plagioclase and have garnet present, dacite magma generation must have occurred in the mantle. There is geochemical and mineralogical evidence for the Kefalos and KPT rhyolites being generated by fractional crystallization from magmas similar to the Kefalos dacites. However, the few distinctions between KPT and Kefalos rhyolites (KPT is more voluminous, contains more crystals, has lower whole-rock U and Th contents, and lower MgO-SiO2, but higher Al2O3-FeOtot in biotite) suggest slightly different conditions in the magma chambers. These observations, together with increasing explosivity of the volcanic products from ~3 Ma to 0.16 Ma, may indicate that the build-up to the large KPT eruption could be the result of an increase in magmatic water input in the system through time.

  5. The timing of the Black Sea flood event: Insights from modeling of glacial isostatic adjustment

    Science.gov (United States)

    Goldberg, Samuel L.; Lau, Harriet C. P.; Mitrovica, Jerry X.; Latychev, Konstantin

    2016-10-01

    We present a suite of gravitationally self-consistent predictions of sea-level change since Last Glacial Maximum (LGM) in the vicinity of the Bosphorus and Dardanelles straits that combine signals associated with glacial isostatic adjustment (GIA) and the flooding of the Black Sea. Our predictions are tuned to fit a relative sea level (RSL) record at the island of Samothrace in the north Aegean Sea and they include realistic 3-D variations in viscoelastic structure, including lateral variations in mantle viscosity and the elastic thickness of the lithosphere, as well as weak plate boundary zones. We demonstrate that 3-D Earth structure and the magnitude of the flood event (which depends on the pre-flood level of the lake) both have significant impact on the predicted RSL change at the location of the Bosphorus sill, and therefore on the inferred timing of the marine incursion. We summarize our results in a plot showing the predicted RSL change at the Bosphorus sill as a function of the timing of the flood event for different flood magnitudes up to 100 m. These results suggest, for example, that a flood event at 9 ka implies that the elevation of the sill was lowered through erosion by ∼14-21 m during, and after, the flood. In contrast, a flood event at 7 ka suggests erosion of ∼24-31 m at the sill since the flood. More generally, our results will be useful for future research aimed at constraining the details of this controversial, and widely debated geological event.

  6. Cascading ocean basins: numerical simulations of the circulation and interbasin exchange in the Azov-Black-Marmara-Mediterranean Seas system

    Science.gov (United States)

    Stanev, Emil Vassilev; Grashorn, Sebastian; Zhang, Yinglong Joseph

    2017-08-01

    In this paper, we use the unstructured grid model SCHISM to simulate the thermohydrodynamics in a chain of baroclinic, interconnected basins. The model shows a good skill in simulating the horizontal circulation and vertical profiles of temperature, salinity, and currents. The magnitude and phases of the seasonal changes of circulation are consistent with earlier observations. Among the mesoscale and subbasin-scale circulation features that are realistically simulated are the anticyclonic coastal eddies, the Sebastopol and Batumi eddies, the Marmara Sea outflow around the southern coast of the Limnos Island, and the pathway of the cold water originating from the shelf. The superiority of the simulations compared to earlier numerical studies is demonstrated with the example of model capabilities to resolve the strait dynamics, gravity currents originating from the straits, high-salinity bottom layer on the shallow shelf, as well as the multiple intrusions from the Bosporus Strait down to 700 m depth. The warm temperature intrusions from the strait produce the warm water mass in the intermediate layers of the Black Sea. One novel result is that the seasonal intensification of circulation affects the interbasin exchange, thus allowing us to formulate the concept of circulation-controlled interbasin exchange. To the best of our knowledge, the present numerical simulations, for the first time, suggest that the sea level in the interior part of the Black Sea can be lower than the sea level in the Marmara Sea and even in some parts of the Aegean Sea. The comparison with observations shows that the timings and magnitude of exchange flows are also realistically simulated, along with the blocking events. The short-term variability of the strait transports is largely controlled by the anomalies of wind. The simulations demonstrate the crucial role of the narrow and shallow strait of Bosporus in separating the two pairs of basins: Aegean-Marmara Seas from one side and Azov

  7. 7 CFR 1437.310 - Sea grass and sea oats.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  8. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  9. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  10. Sea Lion Diet Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions pup and breed at four of the nine Channel Islands in southern California. Since 1981, SWFSC MMTD has been conducting a diet study of sea lions...

  11. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    Science.gov (United States)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-05-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative influences remain ambiguous. A related issue is that an assumed 3-kyr lag between boreal insolation maxima and sapropel mid-points remains to be tested. Here we present new geochemical and ice-volume-corrected planktonic foraminiferal stable isotope records for sapropels S1 (Holocene), S3, S4, and S5 (Marine Isotope Stage 5) in core LC21 from the southern Aegean Sea. The records have a radiometrically constrained chronology that has already been synchronised with the Red Sea relative sea-level record, and this allows detailed examination of the timing of sapropel deposition relative to insolation, sea-level, and African monsoon changes. We find that sapropel onset was near-synchronous with monsoon run-off into the eastern Mediterranean, but that insolation-sapropel/monsoon phasings were not systematic through the last glacial cycle. These latter phasings instead appear to relate to sea-level changes. We propose that persistent meltwater discharges into the North Atlantic (e.g., at glacial terminations) modified the timing of sapropel deposition by delaying the timing of peak African monsoon run-off. These observations may reconcile apparent model-data offsets with respect to the orbital pacing of the African monsoon. Our observations also imply that the previous assumption of a systematic 3-kyr lag between insolation maxima and sapropel midpoints may lead to overestimated insolation-sapropel phasings. Finally, we surmise that both sea-level rise and monsoon run-off contributed to surface-water buoyancy changes at times of sapropel deposition, and their relative influences differed per sapropel case, depending on their magnitudes. Sea-level rise was clearly important for

  12. Temporal Variability of Zooplankton (2000-2013) in the Levantine Sea: Significant Changes Associated to the 2005-2010 EMT-like Event?

    Science.gov (United States)

    Ouba, Anthony; Abboud-Abi Saab, Marie; Stemmann, Lars

    2016-01-01

    In this study, we investigated, for the first time, the potential impact of environmental changes on zooplankton abundance over a fourteen year period (2000-2013) at an offshore station in the Eastern Mediterranean Sea (the Levantine basin, offshore Lebanon). Samples were collected monthly and analyzed using the semi-automated system ZooScan. Salinity, temperature and phytoplankton abundance (nano and microphytoplankton) were also measured. Results show no significant temporal trend in sea surface temperature over the years. Between 2005-2010, salinity in the upper layer (0-80 m) of the Levantine basin increased (~0.3°C). During this 5 year period, total zooplankton abundance significantly increased. These modifications were concomitant to the activation of Aegean Sea as a source of dense water formation as part of the "Eastern Mediterranean Transient-like" event. The results of the present study suggested that zooplankton benefited from enhanced phytoplankton production during the mixing years of the event. Changes in the phenology of some taxa were observed accordingly with a predominantly advanced peak of zooplankton abundance. In conclusion, long-term changes in zooplankton abundance were related to the Levantine thermohaline circulation rather than sea surface warming. Sampling must be maintained to assess the impact of long-term climate change on zooplankton communities.

  13. Temporal Variability of Zooplankton (2000-2013 in the Levantine Sea: Significant Changes Associated to the 2005-2010 EMT-like Event?

    Directory of Open Access Journals (Sweden)

    Anthony Ouba

    Full Text Available In this study, we investigated, for the first time, the potential impact of environmental changes on zooplankton abundance over a fourteen year period (2000-2013 at an offshore station in the Eastern Mediterranean Sea (the Levantine basin, offshore Lebanon. Samples were collected monthly and analyzed using the semi-automated system ZooScan. Salinity, temperature and phytoplankton abundance (nano and microphytoplankton were also measured. Results show no significant temporal trend in sea surface temperature over the years. Between 2005-2010, salinity in the upper layer (0-80 m of the Levantine basin increased (~0.3°C. During this 5 year period, total zooplankton abundance significantly increased. These modifications were concomitant to the activation of Aegean Sea as a source of dense water formation as part of the "Eastern Mediterranean Transient-like" event. The results of the present study suggested that zooplankton benefited from enhanced phytoplankton production during the mixing years of the event. Changes in the phenology of some taxa were observed accordingly with a predominantly advanced peak of zooplankton abundance. In conclusion, long-term changes in zooplankton abundance were related to the Levantine thermohaline circulation rather than sea surface warming. Sampling must be maintained to assess the impact of long-term climate change on zooplankton communities.

  14. Radioactivity concentrations in mussel (Mytilus galloprovincialis) of Turkish Sea coast and contribution of ²¹⁰Po to the radiation dose.

    Science.gov (United States)

    Kılıç, Önder; Belivermiş, Murat; Cotuk, Yavuz; Topçuoğlu, Sayhan

    2014-03-15

    Radionuclides levels were determined in indigenous and transplanted mussels (Mytilus galloprovincialis) collected from Turkish marine environment. Radioactivity concentrations of ¹³⁷Cs, ⁴⁰K, ²²⁶Ra, ²²⁸Ra, ²¹⁰Po and ²¹⁰Pb were determined in the soft tissues of the mussel samples collected in Bosphorus Strait, Coasts of Black Sea, Marmara Sea and Aegean Sea. Mussel transplantation was carried out by using mussel cages in Levantine Sea coast since M. galloprovincialis did not naturally adapt along the coast. The average activity concentrations of ¹³⁷Cs, ⁴⁰K, ²²⁶Ra, ²²⁸Ra, ²¹⁰Po and ²¹⁰Pb in the coastline of Turkey were found to be 0.7±0.1, 469±24, 0.9±0.1, 1.0±0.1, 122±4 and 10.9±0.9 Bq kg⁻¹ in dry weight (dw), respectively. The average of ²¹⁰Po/²¹⁰Pb ratio was found to be ∼14. Total annual effective ²¹⁰Po dose was calculated to be in the range of 0.25-3.30 μSv due to mussel consumption. Radioactivity and dose levels were compared with those of similar studies carried out in Mediterranean countries.

  15. All That Unplowed Sea

    Science.gov (United States)

    MOSAIC, 1975

    1975-01-01

    Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)

  16. The Caspian Sea Environment

    Science.gov (United States)

    Kostianoy, Andrey; Kosarev, A.

    The systematic description of the knowledge accumulated on the physical oceanography, marine chemistry and pollution, and marine biology of the Caspian Sea forms the basis of this book. It presents the principal characteristic features of the environmental conditions of the sea and their changes in the second half of the 20th century. At present, the principal problems of the Caspian Sea are related to the interannual sea level changes and their forecast and to the estimation of the intensity of the chemical pollution of the sea and its impact upon the biota.

  17. SEA and planning

    DEFF Research Database (Denmark)

    Stoeglehner, G.; Brown, A.L.; Kørnøv, Lone

    2009-01-01

    As the field of strategic environmental assessment (SEA) has matured, the focus has moved from the development of legislation, guidelines and methodologies towards improving the effectiveness of SEA. Measuring and of course achieving effectiveness is both complex and challenging. This paper...... suggests that SEA professionals need to consider 'democratic effectiveness' as well as 'environmental effectiveness' in both 'direct' and 'indirect' outputs. The effectiveness of SEA depends critically on the context within which SEA legislation and guidelines are understood and implemented......, and the relationship of the SEA to the planning activity itself. This paper focuses on the influence that planners have in these implementation processes, postulating the hypothesis that these are key players in achieving effectiveness in SEA. Based upon implementation theory and empirical experience, the paper...

  18. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  19. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  20. Sea piracy and law of the sea

    OpenAIRE

    Hanif, Muhammad Tahir

    2010-01-01

    As the sea become world’s largest source to trade between the nations during the last few decades. Of course there are lots of problems in this regards when we are using the sea on such a large scale. The problem of piracy is most dangerous problems, among the all problems of the sea at the same time. Nations are trying to control this crime individually and collectively but the problem is still on its peak. Lots of international and national laws and conventions are held in this ...

  1. Salish Sea Genetics - Salish Sea genetic inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Salish Sea comprises most of the Puget Sound water area. Marine species are generally assemblages of discrete populations occupying various ecological niches....

  2. Inferences of Integrated Lithospheric Strength from Plate-Scale Analyses of Deformation Observed in the Aegean-Anatolian Region and the Indian Ocean

    Science.gov (United States)

    Houseman, Gregory

    2016-04-01

    In the context of a comprehensive review of the rheology and strength of the lithosphere (Marine and Petroleum Geology, 2011, doi:10.1016/j.marpetgeo.2011.05.008), Evgene Burov described the difficulty of extrapolating rock deformation laws derived from laboratory experiments to the time and length scales that apply when the Earth's lithosphere is deformed. Not only does the extrapolation introduce a large uncertainty, but even the relative importance of different possible mechanisms of deformation may be uncertain. Even though lithospheric deformation has a strong conceptual and theoretical basis, it is therefore essential, as Burov argued, that deformation laws for the lithosphere must be calibrated by using observations of deformation that occurs on a lithospheric length scale and at geological strain rates. The influence of regionally varying factors like crustal thickness, geothermal gradient and tectonic environment may induce large variations in how rapidly the lithosphere may deform in response to an applied load, not least in the contrast from continent to ocean. Plates may be deformed by different loading mechanisms but, when deformation is distributed over a broad region, the strain-rate field may be approximately constant with depth and we may integrate the in-plane stress components across the thickness of the lithosphere to derive a depth-averaged constitutive law for the deformation. This approximation is the basis for the thin viscous sheet formulation of lithospheric deformation and, in combination with appropriate observations, it allows us to calibrate the integrated resistance to processes like regional extension or convergence. In this talk I will summarise what we learn about effective lithospheric rheology from two recent studies of the distribution and rates of diffuse deformation of the lithosphere in, firstly the Anatolian-Aegean region, and secondly the Central Indian Ocean. In the first case the distribution of deformation is consistent

  3. Summer Arctic sea fog

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China' s First Arctic Expedition. Based on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind has its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form,which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.

  4. Arctic Sea Level Reconstruction

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    Reconstruction of historical Arctic sea level is very difficult due to the limited coverage and quality of tide gauge and altimetry data in the area. This thesis addresses many of these issues, and discusses strategies to help achieve a stable and plausible reconstruction of Arctic sea level from...... 1950 to today.The primary record of historical sea level, on the order of several decades to a few centuries, is tide gauges. Tide gauge records from around the world are collected in the Permanent Service for Mean Sea Level (PSMSL) database, and includes data along the Arctic coasts. A reasonable...... amount of data is available along the Norwegian and Russian coasts since 1950, and most published research on Arctic sea level extends cautiously from these areas. Very little tide gauge data is available elsewhere in the Arctic, and records of a length of several decades,as generally recommended for sea...

  5. South China Sea Challenge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China's attempts to solve disputes with ASEAN over the South China Sea help regional peace China's marine economy and security are currently faced with new challenges, requiring careful handling, especially in disputes with ASEAN countries and in promoting common development of the South China Sea. The outcome of how this is dealt with could undoubtedly pave the way for solutions to other oceanic disputes. The South China Sea is located south of

  6. Dilemmas in SEA application

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    Dilemmas in SEA Application: The DK Energy SectorIvar Lyhne - lyhne@plan.aau.dk. Based on three years of collaborative research, this paper outlines dilemmas in the application of SEA in the strategic development of the Danish energy sector. The dilemmas are based on concrete examples from practice...... the Danish energy sector) are starting to get it right. Lessons for SEA implementation in similar contexts are proposed....

  7. Pelagic sea snakes dehydrate at sea

    Science.gov (United States)

    Lillywhite, Harvey B.; Sheehy, Coleman M.; Brischoux, François; Grech, Alana

    2014-01-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  8. Pelagic sea snakes dehydrate at sea.

    Science.gov (United States)

    Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, François; Grech, Alana

    2014-05-07

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans.

  9. Mitochondrial Control Region Variability in Mytilus galloprovincialis Populations from the Central-Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Ioannis A. Giantsis

    2014-06-01

    Full Text Available The variable domain 1 (VD1 domain of the control region and a small segment of the rrnaL gene of the F mtDNA type were sequenced and analyzed in 174 specimens of Mytilus galloprovincialis. Samples were collected from eight locations in four Central-Eastern (CE Mediterranean countries (Italy, Croatia, Greece and Turkey. A new primer, specific for the F mtDNA type, was designed for the sequencing procedure. In total 40 different haplotypes were recorded, 24 of which were unique. Aside from the two populations situated in Thermaikos gulf (Northern Aegean, Greece, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and Eastern Mediterranean populations. Eight out of the 40 haplotypes were shared by at least three populations while two of them were found in all populations. ΦST and cluster analysis revealed lack of structuring among CE Mediterranean populations with the exception of those located at the Sea of Marmara and Croatian coast which were highly differentiated. Apart from the species’ inherit dispersal ability, anthropogenic activities, such as the repeated translocations of mussel spat, seem to have played an important role in shaping the current genetic population structure of CE M. galloprovincialis mussels.

  10. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  11. Somalia ... From the Sea

    Science.gov (United States)

    2009-07-01

    from the Sea, p. 7. 65. Robert D. Heinl, Jr., “Inchon, 1950,” in As- sault from the Sea: Essays on the History of Amphibious Warfare, ed. Merrill L...Mohamed Haji. Historical Dictionary of Somalia. New ed. Lanham, Md.: Scare- crow , 2003. Natsios, Andrew S. U.S. Foreign Policy and the Four Horsemen of

  12. SEA in Southern Africa

    CSIR Research Space (South Africa)

    Audouin, M

    2011-01-01

    Full Text Available in a number of them. Despite these trends, however, the opportunities that SEA can offer to facilitate sustainable development are not being realized. In this chapter, the authors describe the emergence of SEA in the post-colonial, democratic context...

  13. Oceanography of marginal seas

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    dioxide in intermediate layers falls from approx. 1000 mu atm in the southern end to approx. 500 mu atm in the northern Red Sea. Temperature in Atlantis II deep and brine level in Discovery deep in the Red Sea seem to be increasing in recent years...

  14. Dilemmas in SEA application

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    Dilemmas in SEA Application: The DK Energy SectorIvar Lyhne - lyhne@plan.aau.dk. Based on three years of collaborative research, this paper outlines dilemmas in the application of SEA in the strategic development of the Danish energy sector. The dilemmas are based on concrete examples from practice...... in the implementation of SEA in the sector, and they concern, e.g., strategic choices in transmission network development and ministerial choices on location of energy production units. The paper outlines the roots of the dilemmas as well as their implications for timing and content of SEA. The verdict is that we (in...... the Danish energy sector) are starting to get it right. Lessons for SEA implementation in similar contexts are proposed....

  15. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    Sensitivity studies show that the radiometer ice concentration estimate can be biased by +10% by anomalous atmospheric emissivity and -20% by anomalous ice surface emissivity. The aim of the sea ice activities in EU 5th FP project IOMASA is to improve sea ice concentration estimates at higher...... spatial resolution. The project is in the process of facilitating an ice concentration observing system through validation and a better understanding of the microwave radiative transfer of the sea ice and overlying snow layers. By use of a novel modelling approach, it is possible to better detect...... and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...

  16. Indicators and SEA

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    Abstract: Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation. Indicators can be seen as part of the implementation...... process helping to understand, communicate and, integrate important environmental issues in planning and decision-making. On the other hand, use of indicators can also limit SEA effectiveness, if the ones chosen are biased or limited, if the aggregation gives incorrect interpretation...... and if the information requirement for different target groups is not addressed. Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation...

  17. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    Sensitivity studies show that the radiometer ice concentration estimate can be biased by +10% by anomalous atmospheric emissivity and -20% by anomalous ice surface emissivity. The aim of the sea ice activities in EU 5th FP project IOMASA is to improve sea ice concentration estimates at higher...... spatial resolution. The project is in the process of facilitating an ice concentration observing system through validation and a better understanding of the microwave radiative transfer of the sea ice and overlying snow layers. By use of a novel modelling approach, it is possible to better detect...... and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...

  18. Offshore seismicity in the western Marmara Sea, Turkey, revealed by ocean bottom observation

    Science.gov (United States)

    Yamamoto, Yojiro; Takahashi, Narumi; Citak, Seckin; Kalafat, Doǧan; Pinar, Ali; Gürbüz, Cemil; Kaneda, Yoshiyuki

    2015-04-01

    The North Anatolian Fault (NAF) extends 1600 km westward from a junction with the East Anatolian Fault at the Karliova Triple Junction in eastern Turkey, across northern Turkey and into the Aegean Sea, accommodating about 25 mm/yr of right-lateral motion between Anatolia and the Eurasian plate. Since 1939, devastating earthquakes with magnitude greater than seven ruptured NAF westward, starting from 1939 Erzincan (Ms=7.9) at the eastern Turkey and including the latest 1999 Izmit-Golcuk (Ms=7.7) and the Duzce (Ms=7.4) earthquakes in the Marmara region. Considering the fault segments ruptured by the May 24th, 2014 Northern Aegean earthquake (Mw=6.9), the only un-ruptured segments left behind the 1600 km long NAF locate beneath the Marmara Sea and those segments keep their mystery due to their underwater location. To consider the earthquake hazard and disaster mitigation, the detailed information about fault geometry and its stick-slip behavior beneath the western Marmara Sea is very important. Thus, we started to operate a series of ocean bottom seismographic (OBS) observations to estimate the fault geometry from microearthquake distribution. As a first step, we deployed 3 pop-up type OBSs on 20th of March 2014 as a trial observation, and recovered them on 18th of June 2014. Although one of the OBSs worked only 6 days from the start of the observation, other two OBSs functioned properly during the whole 3-month observation period. We first searched for the microearthquakes missing by the land seismic network and estimated their precious location by using the initial 6 days data, i.e., using all the temporary OBS stations. Although there are only 3 earthquakes listed on the Kandilli Observatory and Earthquake Research Institute (KOERI) catalogue, we could identify 41 earthquakes with more than 5 picking data of P and S first arrivals, and two-third of them located within the OBS network. We found the earthquake cluster along the main NAF and whose depth interval is 12

  19. Mud volcano monitoring and seismic events along the North Anatolian Fault (Sea of Marmara)

    Science.gov (United States)

    Javad Fallahi, Mohammad; Lupi, Matteo; Mazzini, Adriano; Polonia, Alina; D'Alessandro, Antonino; D'Anna, Giuseppe; Gasperini, Luca

    2017-04-01

    The Sea of Marmara, a pull-apart basin formed along the northern strand of the North Anatolian Fault (NAF) system, is considered a seismic gap, that will be filled in the next decades by a large magnitude (M>7) earthquake, close to the Istanbul Metropolitan area (12 million inhabitants). For this reason, several marine geological and geophysical studies have been carried out in this region, starting from the destructive 1999 Mw 7.4 Izmit earthquake, to gather information relative to seismogenic potential of major fault strands. Together with these studies, in the frame of EC projects (i.e., MarmESONET and Marsite, among others), an intensive program of long-term monitoring of seismogenic faults was carried out using seafloor observatories deployed during several expeditions led by Italian, French and Turkish groups. These expeditions included MARM2013, on board of the R/V Urania, of the Italian CNR, when four ocean bottom seismometers (OBS) were deployed in the central part of the Sea of Marmara, at depths between 550 and 1000 m. One of the main aims of the experiment was to assess the long-term seismic activity along an active segment of the NAF, which connects the central and the western basins (depocenters), where the principal deformation zone appears relatively narrow and almost purely strike-slip. The present study shows the results of processing and analysis of continuous data records from these OBS stations during 50 days. We were able to detect seismic signal produced by an active mud volcano located close to the NAF trace, from about 3 to 6 km of distance from the OBS stations. Additionally, we captured the May 24, 2014, Mw 6.9 strike-slip earthquake occurred in the northern Aegean Sea between Greece and Turkey, which caused serious damage on the Turkish island of Imbros and the cities of Edirne and Çanakkale, as well as on the Greek island of Lemnos. The earthquake nucleated on the westward continuation of the NAF system in the NE Aegean Sea, and was

  20. Dead sea water intoxication.

    Science.gov (United States)

    Levy-Khademi, Floris; Brooks, Rebecca; Maayan, Channa; Tenenbaum, Ariel; Wexler, Isaiah D

    2012-08-01

    Near drowning in the Dead Sea is associated with both respiratory manifestations and severe electrolyte abnormalities. It is often difficult to distinguish between the contributions of sea water aspiration or ingestion to clinical manifestations. We present a unique case of accidental ingestion of a large amount of Dead Sea water through a gastrostomy tube in which a patient with familial dysautonomia presented with severe electrolyte disturbances. Forced diuresis with large amounts of intravenous fluids resulted in clinical and biochemical improvement. Full recovery was achieved after 2 days of treatment.

  1. Combined effect of vacuum-packaging and oregano essential oil on the shelf-life of Mediterranean octopus (Octopus vulgaris) from the Aegean Sea stored at 4 degrees C.

    Science.gov (United States)

    Atrea, I; Papavergou, A; Amvrosiadis, I; Savvaidis, I N

    2009-04-01

    The present study evaluated the use of vacuum packaging (alone) or with addition of oregano essential oil (EO), as an antimicrobial treatment for shelf-life extension of fresh Mediterranean octopus stored under refrigeration for a period of 23 days. Four different treatments were tested: A, control sample; under aerobic storage in the absence of oregano essential oil; VP, under vacuum packaging in the absence of oregano essential oil; and VO1, VO2, treated samples with oregano essential oil 0.2 and 0.4% (v/w), respectively, under VP. Of all the microorganisms enumerated, Pseudomonas spp., H2S-producing bacteria and lactic acid bacteria (LAB) were the groups that prevailed in octopus samples, irrespective of antimicrobial treatment. With regard to the chemical freshness indices determined, thiobarbituric acid (TBA) values were low in all octopus samples, as could have been expected from the low fat content of the product. Both trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) values of oregano treated under VP octopus samples were significantly lower compared to control samples during the entire refrigerated storage period. Based primarily on sensory evaluation (odor), the use of VP, VO1 and VO2 extended the shelf-life of fresh Mediterranean octopus by ca. 3, 11 and 20 days, respectively.

  2. Thiol pools and glutathione redox ratios as possible indicators of copper toxicity in the green macroalgae Enteromorpha spp. from the Scheldt Estuary (SW Netherlands, Belgium) and Thermaikos Gulf (Greece, N Aegean Sea)

    NARCIS (Netherlands)

    Rijstenbil, J.W.; Haritonidis, S.; Malea, P.; Seferlis, M.; Wijnholds, J.A.

    1998-01-01

    Defence mechanisms against Cu toxicity were examined in two dominant Enteromorpha species from two coastal water types. The macroalgae were collected at three locations in the eulittoral of the Scheldt Estuary (Netherlands, Belgium) and the Thermaikos Gulf (Greece). For 10 days E. prolifera (Scheldt

  3. Effects of cadmium, zinc and nitrogen status on nonprotein thiols in the macroalgae Enteromorpha spp. from the Scheldt Estuary (SW Netherlands, Belgium) and Thermaikos Gulf (Greece, N Aegean Sea)

    NARCIS (Netherlands)

    Malea, P.; Rijstenbil, J.W.; Haritonidis, S.

    2006-01-01

    Enteromorpha prolifera (Scheldt Estuary) and E. linza (Thermaikos Gulf) were incubated at three salinities with 100 and 200 µg L-1Cd and Zn. The objective was to measure effects of Cd, Zn and nitrogen (N) status on the pools of metal-binding non-protein thiols: glutathione and phytochelatins, (?-glu

  4. The north Sulu Sea productivity

    Science.gov (United States)

    Xiao, Z.

    2009-12-01

    The Sulu Sea is a part of the western North Pacific. It is a closed sea for its deep water and a semi-closed sea for its upper layer. The Sulu Sea exchanges mainly surface waters with the South China Sea and the Celebes Sea. The Sulu Sea is more productive than the adjacent South China Sea (Jones, 2002). On the basis of MERIS satellite observations from 2002 to 2008, we focus on the high-chlorophyll area as an indicator of the abundance of primary productivity in the Sulu Sea. Strong chlorophyll concentration in the north Sulu Sea close to the Mindoro Strait mainly occurs from December to March and low chlorophyll concentration happens in April to November. The adjacent South China Sea on the other side of Mindoro Strait has shown persistent signs of low chlorophyll concentration. Based on 1/8° Global Navy Coastal Ocean Model, the intrusion of the South China Sea waters through the Mindoro Strait to the Sulu Sea from April to November is the main reason for the low chlorophyll concentration observed in the north Sulu Sea. During April to November, the South China Sea waters flow through the Mindoro Strait and stay on the surface of the north Sulu Sea because of their low density. The north Sulu Sea waters mix with fresher waters coming from the South China Sea without new nutrients supply. When the inflow from South China Sea to Sulu Sea ceases in December to March, the upwelling due to the summer monsoon wind becomes an important mechanism supplying deep nutrients to the surface water which lead to high chlorophyll concentration. Jones, I.S.F., 2002. Primary production in the Sulu Sea. Proceedings of the Indian Academy of Sciences-Earth and Planetary Sciences 111, 209-213.

  5. Marine caves of the Mediterranean Sea: a sponge biodiversity reservoir within a biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Vasilis Gerovasileiou

    Full Text Available Marine caves are widely acknowledged for their unique biodiversity and constitute a typical feature of the Mediterranean coastline. Herein an attempt was made to evaluate the ecological significance of this particular ecosystem in the Mediterranean Sea, which is considered a biodiversity hotspot. This was accomplished by using Porifera, which dominate the rocky sublittoral substrata, as a reference group in a meta-analytical approach, combining primary research data from the Aegean Sea (eastern Mediterranean with data derived from the literature. In total 311 species from all poriferan classes were recorded, representing 45.7% of the Mediterranean Porifera. Demospongiae and Homoscleromorpha are highly represented in marine caves at the family (88%, generic (70%, and species level (47.5%, the latter being the most favored group along with Dictyoceratida and Lithistida. Several rare and cave-exclusive species were reported from only one or few caves, indicating the fragmentation and peculiarity of this unique ecosystem. Species richness and phylogenetic diversity varied among Mediterranean areas; the former was positively correlated with research effort, being higher in the northern Mediterranean, while the latter was generally higher in caves than in the overall sponge assemblages of each area. Resemblance analysis among areas revealed that cavernicolous sponge assemblages followed a pattern quite similar to that of the overall Mediterranean assemblages. The same pattern was exhibited by the zoogeographic affinities of cave sponges: species with Atlanto-Mediterranean distribution and Mediterranean endemics prevailed (more than 40% each, 70% of them having warm-water affinities, since most caves were studied in shallow waters. According to our findings, Mediterranean marine caves appear to be important sponge biodiversity reservoirs of high representativeness and great scientific interest, deserving further detailed study and protection.

  6. Sea Scallop Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Sea Scallop Survey began in 1980 and has covered an area from Cape Hatteras to Georges Bank. The survey aims to determine the distribution and...

  7. Pollution of coastal seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    cities. Various types of wastes, if not properly treated, would cause serious pollution of these shallow seas endangering marine life and spoiling recreational facilities. Different polluting agents like sewage, chemicals, industrial coolants etc...

  8. A Sea Floor Penetrometer.

    Science.gov (United States)

    processed through an analog-to-digital (A/D) converter, and stored in the memory of a mini-computer. Computer algorithms are applied to the deceleration data to provide real-time sea floor classification.

  9. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest...

  10. South China Sea.

    Science.gov (United States)

    Morton, B; Blackmore, G

    2001-12-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the

  11. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  12. South China Sea

    Science.gov (United States)

    Morton, Brian; Blackmore, Graham

    2001-01-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

  13. Contemporary sea level rise.

    Science.gov (United States)

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion.

  14. Projecting future sea level

    Science.gov (United States)

    Cayan, Daniel R.; Bromirski, Peter; Hayhoe, Katharine; Tyree, Mary; Dettinger, Mike; Flick, Reinhard

    2006-01-01

    California’s coastal observations and global model projections indicate that California’s open coast and estuaries will experience increasing sea levels over the next century. Sea level rise has affected much of the coast of California, including the Southern California coast, the Central California open coast, and the San Francisco Bay and upper estuary. These trends, quantified from a small set of California tide gages, have ranged from 10–20 centimeters (cm) (3.9–7.9 inches) per century, quite similar to that estimated for global mean sea level. So far, there is little evidence that the rate of rise has accelerated, and the rate of rise at California tide gages has actually flattened since 1980, but projections suggest substantial sea level rise may occur over the next century. Climate change simulations project a substantial rate of global sea level rise over the next century due to thermal expansion as the oceans warm and runoff from melting land-based snow and ice accelerates. Sea level rise projected from the models increases with the amount of warming. Relative to sea levels in 2000, by the 2070–2099 period, sea level rise projections range from 11–54 cm (4.3–21 in) for simulations following the lower (B1) greenhouse gas (GHG) emissions scenario, from 14–61 cm (5.5–24 in) for the middle-upper (A2) emission scenario, and from 17–72 cm (6.7–28 in) for the highest (A1fi) scenario. In addition to relatively steady secular trends, sea levels along the California coast undergo shorter period variability above or below predicted tide levels and changes associated with long-term trends. These variations are caused by weather events and by seasonal to decadal climate fluctuations over the Pacific Ocean that in turn affect the Pacific coast. Highest coastal sea levels have occurred when winter storms and Pacific climate disturbances, such as El Niño, have coincided with high astronomical tides. This study considers a range of projected future

  15. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  16. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  17. Kara Sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Osvath, I.; Povinec, P.P.; Baxter, M.S. [Marine Environment Laboratory, International Atomic Energy Agency, B.P. 800 MC (Monaco)

    1999-09-30

    Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea and Novaya Zemlya bays as well as soil from the shore of Abrosimov bay have shown that radionuclide contamination of the open Kara Sea is mainly due to global fallout, with smaller contributions from the Sellafield reprocessing plant, the Chernobyl accident run-off from the Ob and Yenisey rivers and local fallout. Computer modelling results have shown that maximum annual doses of approximately 1 mSv are expected for a hypothetical critical group subsisting on fish caught in the Novaya Zemlya bays whereas populations living on the mainland can be expected to receive doses at least three orders of magnitude lower.

  18. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  19. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  20. Dynamics of sea level variations in the coastal Red Sea

    Science.gov (United States)

    Churchill, James; Abulnaja, Yasser; Nellayaputhenpeedika, Mohammedali; Limeburner, Richard; Lentz, Steven

    2016-04-01

    Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. While considerable scientific work has been directed at tidal and seasonal variations of Red Sea water level, very little attention has been given to elevation changes in an 'intermediate' frequency band, with periods of 2-30 d, even though motions in this band account for roughly half of the sea level variance in central Red Sea. We examined the sea level signal in this band using AVISO sea level anomaly (SLA) data, COARDAS wind data and measurements from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters. Empirical orthogonal function analysis of the SLA data indicates that longer-period (10-30 d) sea level variations in the intermediate band are dominated by coherent motions in a single mode that extends over most of the Red Sea axis. Idealized model results indicate that this large-scale mode of sea level motion is principally due to variations in the large-scale gradient of the along-axis wind. Our analysis indicates that coastal sea level motions at shorter periods (2-10 d) are principally generated by a combination of direct forcing by the local wind stress and forcing associated with large-scale wind stress gradients. However, also contributing to coastal sea level variations in the intermediate frequency band are mesoscale eddies, which are prevalent throughout the Red Sea basin, have a sea level signal of 10's of cm and produce relatively small-scale (order 50 km) changes in coastal sea level.

  1. Mediterranean, our sea

    Science.gov (United States)

    Markaki, Foteini

    2017-04-01

    My school (1o EPAL Ymittos -Athens, Greece) is a technical school of secondary education and throughout this school year being drafted a program of environmental education. The main theme is the Mediterranean Sea, the biggest closed sea extending between three continents. Topics studied: 1. Biodiversity and the risks threat. 2. The geophysics that characterize (earthquakes, volcanoes explosions, etc). 3. The Mediterranean Sea as environment anthropogenesis, a mosaic of other cultures and even place current notions of social phenomena (refugees). Pedagogical Objectives: Cognitive/Enviromental: 1. To investigate and understand the biodiversity of the Mediterranean Sea and the risks to threaten and phenomena that characterize. 2. To understand the position of the Mediterranean Sea in the land and the role of the historical, cultural and social human environment. 3. To come in contact with texts literary, social, articles on the Mediterranean. Psychomotor: 1. To work together and collect information for the Mediterranean Sea. 2. Experiential approach to the natural environment. 3. Develop critical thinking. 4. Undertake responsibilities for the presentation of the program. Emotional: 1. To feel joy from participation in the program. 2. Being sensitized and configure attitudes and actions of respect towards the environment. Methodology implementation: Teamwork. Interdisciplinary - holistic to dissemination of program recordings to courses curriculum. Study in the field. Gathering information from newspapers, magazines, internet, maps, and photographs. Experiential method- Project. Assessment methods and self-assessment. Fields of courses: Greek language- History- Biology- Chemistry- Technology Dissemination of results: Make a page of social media (facebook), a blog, enhancing environmental awareness via video, make an electronic poster.

  2. Seasonal Change of Steric Sea Level in the GIN Seas

    Institute of Scientific and Technical Information of China (English)

    LI Lei; WANG Huijuan; SUN Ruili

    2011-01-01

    The Greenland Sea, Iceland Sea, and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans, where significant water and energy exchange take place, and play an important role in global climate change. In this study steric sea level, associated with temperature and salinity, in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0). A method proposed by Tabata et al. is used to calculate steric sea level, in which, steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC), recpectively. Total steric sea level (TSSL) change is the sum of TC and SC. The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea, whereas TC contributes more in the Norwegian and the Iceland Seas. Annual variation of TSSL is larger than 50ram over most regions of the GIN Seas, and can be larger than 200mm at some locations such as 308mm at 76.5°N, 12.5°E and 246mm at 77.50N, 17.5°W.

  3. Analysis of Sea Spikes in Radar Sea Clutter Data

    NARCIS (Netherlands)

    Melief, H.W.; Greidanus, H.; Genderen, P. van; Hoogeboom, P.

    2006-01-01

    Abstract—In this paper three sets of high-resolution, coherent, and polarimetric radar sea clutter data are analyzed and compared with radar sea clutter models. The nature of the data allows a thorough analysis of the power, polarization and velocity of the sea clutter. It is shown that these

  4. Analysis of Sea Spikes in Radar Sea Clutter Data

    NARCIS (Netherlands)

    Melief, H.W.; Greidanus, H.; Genderen, P. van; Hoogeboom, P.

    2006-01-01

    Abstract—In this paper three sets of high-resolution, coherent, and polarimetric radar sea clutter data are analyzed and compared with radar sea clutter models. The nature of the data allows a thorough analysis of the power, polarization and velocity of the sea clutter. It is shown that these quanti

  5. Air-sea exchange studies at the North Sea

    NARCIS (Netherlands)

    Leeuw, G. de; Eijk, A.M.J. van; Kunz, G.J.; Veefkind, P.J.

    1996-01-01

    The North Sea can be considered as a local 'inner' sea in which many processes are quite different from these over the open ocean. The surrounding land has a major influence, being the source for man-made aerosols and gases, whereas the North Sea acts as a sink for these. At the same time the North

  6. SEA LEVEL (TOPEX/POSEIDON)

    Data.gov (United States)

    National Aeronautics and Space Administration — Sea level rise is caused by the thermal expansion of sea water due to climate warming and widespread melting of land ice. The TOPEX/POSEIDON mission a joint...

  7. Atlantic Flyway Sea Duck Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atlantic Flyway Sea Duck Survey, conducted from 1991 to 2002 by the U.S. Fish and Wildlife Service, was established to record sea duck numbers using near shore...

  8. Seafloor Control on Sea Ice

    Science.gov (United States)

    Nghiem, S. V.; Clemente-Colon, P.; Rigor, I. G.; Hall, D. K.; Neumann, G.

    2011-01-01

    The seafloor has a profound role in Arctic sea ice formation and seasonal evolution. Ocean bathymetry controls the distribution and mixing of warm and cold waters, which may originate from different sources, thereby dictating the pattern of sea ice on the ocean surface. Sea ice dynamics, forced by surface winds, are also guided by seafloor features in preferential directions. Here, satellite mapping of sea ice together with buoy measurements are used to reveal the bathymetric control on sea ice growth and dynamics. Bathymetric effects on sea ice formation are clearly observed in the conformation between sea ice patterns and bathymetric characteristics in the peripheral seas. Beyond local features, bathymetric control appears over extensive ice-prone regions across the Arctic Ocean. The large-scale conformation between bathymetry and patterns of different synoptic sea ice classes, including seasonal and perennial sea ice, is identified. An implication of the bathymetric influence is that the maximum extent of the total sea ice cover is relatively stable, as observed by scatterometer data in the decade of the 2000s, while the minimum ice extent has decreased drastically. Because of the geologic control, the sea ice cover can expand only as far as it reaches the seashore, the continental shelf break, or other pronounced bathymetric features in the peripheral seas. Since the seafloor does not change significantly for decades or centuries, sea ice patterns can be recurrent around certain bathymetric features, which, once identified, may help improve short-term forecast and seasonal outlook of the sea ice cover. Moreover, the seafloor can indirectly influence cloud cover by its control on sea ice distribution, which differentially modulates the latent heat flux through ice covered and open water areas.

  9. Pollution around Malta's sea

    OpenAIRE

    Formosa, Nicolette; Duca, Edward

    2014-01-01

    Marine littering is a global concern and every single year tons of litter end up in the ocean all around the globe. It has become such a problem that the waste has amalgamated into huge ‘islands’ floating in the world’s oceans. http://www.um.edu.mt/think/pollution-around-maltas-sea/

  10. Wadden Sea Mud

    DEFF Research Database (Denmark)

    Møller-Jensen, P.

    The present thesis deals with the transport phenomena of estuarine cohesive sediment from a laboratory and a numerical point of view. The cohesive sediment used throughout the whole process was natural mud from the Danish part of the Wadden sea, Ho Bay. In the laboratory, the work was concentrated...

  11. Sailing the Cyber Sea

    Science.gov (United States)

    2012-04-01

    years, the Internet 4 years, and the iPod 3 years, while Facebook added 200 million users in less than 1 year. And finally, if Facebook were a... Apple ] gets an iPhone. It’s not an acceptable trade.” New Thinking In the context of security, unleashing the power of the Cyber Sea has changed

  12. Wadden Sea Mud

    DEFF Research Database (Denmark)

    Møller-Jensen, P.

    The present thesis deals with the transport phenomena of estuarine cohesive sediment from a laboratory and a numerical point of view. The cohesive sediment used throughout the whole process was natural mud from the Danish part of the Wadden sea, Ho Bay. In the laboratory, the work was concentrated...

  13. Pollution around Malta's sea

    OpenAIRE

    Formosa, Nicolette

    2014-01-01

    Marine littering is a global concern and every single year tons of litter end up in the ocean all around the globe. It has become such a problem that the waste has amalgamated into huge ‘islands’ floating in the world’s oceans. http://www.um.edu.mt/think/pollution-around-maltas-sea/

  14. Solar Sea Power

    Science.gov (United States)

    Zener, Clarence

    1976-01-01

    In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)

  15. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s. Radi...

  16. Solomon's Sea and [Pi

    Science.gov (United States)

    Simoson, Andrew J.

    2009-01-01

    This paper is a whimsical survey of the various explanations which might account for the biblical passage in I Kings 7:23 that describes a round object--a bronze basin called Solomon's Sea--as having diameter ten cubits and circumference thirty cubits. Can the biblical pi be any number other than 3? We offer seven different perspectives on this…

  17. Deep-sea fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Damare, S.

    The deep-sea environment, despite being rich in mineral nutrients and near-saturation levels of oxygen, because of its darkness is not conducive to photosynthesis, the process that sustains life on earth. If a liigh abundance and diversity of life...

  18. Climate change and Sea level rise: Potential impact on the coast of the Edremit Plain, NW Turkey.

    Science.gov (United States)

    Curebal, Isa; Efe, Recep; Soykan, Abdullah; Sonmez, Suleyman

    2015-04-01

    Over the past century, most of the world's mountain glaciers and the ice sheets have lost mass due to global warming. When the temperature exceeds a particular level, glaciers and polar ice caps will continue to lose mass. Recent studies report that low-lying coastal areas will be seriously affected by sea level rise. Changes in the amount of natural and anthropogenic greenhouse gases and aerosols had a warming effect on the global climate during last century. Thus, the pace of melting of ice sheets increased, and, accordingly, sea level began to rise faster. Rise in sea level between 1961 and 2003 was equal to 1.8 mm/year while it was 3.1 mm/year between 1993 and 2003. The total rise in the 20th century is estimated to be between 17 and 19 cm. The models based on the sea level change indicate that the average global temperature at the end of the 21st century will increase by 0.3°C - 6.4°C. Global sea level is projected to rise 8-25 cm by 2030, relative to 2000 levels, 18-48 cm by 2050, and 50-140 cm by 20110. The Edremit Plain lies between Mount Madra and the Kaz Mountains on the coast of Aegean Sea in NW Turkey. It is lowland with an area of 141 km2. The widest part of the plain is 16 km along the E - W direction. The N - S direction amounts to a width of 15 km. The plain is covered with alluvial deposits that settled in the Quaternary Period. The elevation ranges from 0 to 50 m a.s.l. in the plain. This study aims to determine how the low-lying coastal land areas of the Edremit Plain may be affected by possible changes in sea level. Elevation dataset is based on the digital elevation model (DEM) of Landsat ETM + satellite images. To that end, satellite images were used to draw the current coastline. Curves of 2.5, 5, and 10 m were drawn through the use of maps with a scale of 1/25.000. Later on, the areas of the fields between these points were calculated. Current estimates show that 2.5 m rise in sea level will cause sea water to cover an area of 8.6 km2 (%14

  19. Analitik Hiyerarşi Prosesi Yaklaşımı Kullanılarak Mobilya Sektörü İçin Ege Bölgesi’nde Hedef Pazarın Belirlenmesi(Determination of Target Market in Aegean Region for Furniture Sector by Using Analytical Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Murat TOKSARI

    2007-01-01

    Full Text Available Businesses have to choose their target markets according to their goals, no matter in which sector they operate. In this study, analytical hierarchy process (AHP, which is an approach making businesses able to choose the best way in all situations by evaluating all strategies for choosing target markets, is used in order to determine target market . AHP is a method, which makes us to be able to determine the superiority of that will be used to choose by systematically comparing and evaluating them. In this study an application to choose market in Aegean Region for furniture sector using AHP method is carried out.

  20. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Directory of Open Access Journals (Sweden)

    K. Sevastou

    2013-07-01

    Full Text Available The long-held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and microbes, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean Basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine spanning over 4 km in depth revealed a high diversity, irrespective of the benthic group or level of taxonomic analysis. A common decreasing bathymetric trend was detected for meiobenthic abundance, major taxa diversity and nematode genera richness, but no differences were found between the two habitats (basin vs slope. In contrast, microbial richness is significantly higher at the basin ecosystem and tends to increase with depth. Multivariate analyses (β- and δ-diversity and ordination analysis complemented these results and underlined the high within-habitat variability of benthic communities. Meiofaunal communities in particular were found to change gradually and vary more towards the abyss. On the other hand, microbial communities were highly variable, even among samples of the same area, habitat and bathymetry. A significant proportion of the variation of benthic communities and their descriptors was explained by depth and proxies of food availability (sedimentary pigments and organic content, but the combination of predictor variables and the strength of the relationship varied depending on the data set used (based on type of habitat, benthic component, taxonomic level. This, along with the observed high within-habitat variability suggests that other factors, which tend to vary at local scale (hydrodynamics, substrate

  1. Benthic communities in the deep Mediterranean Sea: exploring microbial and meiofaunal patterns in slope and basin ecosystems

    Science.gov (United States)

    Sevastou, K.; Lampadariou, N.; Polymenakou, P. N.; Tselepides, A.

    2013-07-01

    The long-held perception of the deep sea consisting of monotonous slopes and uniform oceanic basins has over the decades given way to the idea of a complex system with wide habitat heterogeneity. Under the prism of a highly diverse environment, a large dataset was used to describe and compare spatial patterns of the dominant small-size components of deep-sea benthos, metazoan meiofauna and microbes, from Mediterranean basins and slopes. A grid of 73 stations sampled at five geographical areas along the central-eastern Mediterranean Basin (central Mediterranean, northern Aegean Sea, Cretan Sea, Libyan Sea, eastern Levantine) spanning over 4 km in depth revealed a high diversity, irrespective of the benthic group or level of taxonomic analysis. A common decreasing bathymetric trend was detected for meiobenthic abundance, major taxa diversity and nematode genera richness, but no differences were found between the two habitats (basin vs slope). In contrast, microbial richness is significantly higher at the basin ecosystem and tends to increase with depth. Multivariate analyses (β- and δ-diversity and ordination analysis) complemented these results and underlined the high within-habitat variability of benthic communities. Meiofaunal communities in particular were found to change gradually and vary more towards the abyss. On the other hand, microbial communities were highly variable, even among samples of the same area, habitat and bathymetry. A significant proportion of the variation of benthic communities and their descriptors was explained by depth and proxies of food availability (sedimentary pigments and organic content), but the combination of predictor variables and the strength of the relationship varied depending on the data set used (based on type of habitat, benthic component, taxonomic level). This, along with the observed high within-habitat variability suggests that other factors, which tend to vary at local scale (hydrodynamics, substrate structure

  2. The North Sea - A shelf sea in the Anthropocene

    Science.gov (United States)

    Emeis, Kay-Christian; van Beusekom, Justus; Callies, Ulrich; Ebinghaus, Ralf; Kannen, Andreas; Kraus, Gerd; Kröncke, Ingrid; Lenhart, Hermann; Lorkowski, Ina; Matthias, Volker; Möllmann, Christian; Pätsch, Johannes; Scharfe, Mirco; Thomas, Helmuth; Weisse, Ralf; Zorita, Eduardo

    2015-01-01

    Global and regional change clearly affects the structure and functioning of ecosystems in shelf seas. However, complex interactions within the shelf seas hinder the identification and unambiguous attribution of observed changes to drivers. These include variability in the climate system, in ocean dynamics, in biogeochemistry, and in shelf sea resource exploitation in the widest sense by societies. Observational time series are commonly too short, and resolution, integration time, and complexity of models are often insufficient to unravel natural variability from anthropogenic perturbation. The North Sea is a shelf sea of the North Atlantic and is impacted by virtually all global and regional developments. Natural variability (from interannual to multidecadal time scales) as response to forcing in the North Atlantic is overlain by global trends (sea level, temperature, acidification) and alternating phases of direct human impacts and attempts to remedy those. Human intervention started some 1000 years ago (diking and associated loss of wetlands), expanded to near-coastal parts in the industrial revolution of the mid-19th century (river management, waste disposal in rivers), and greatly accelerated in the mid-1950s (eutrophication, pollution, fisheries). The North Sea is now a heavily regulated shelf sea, yet societal goals (good environmental status versus increased uses), demands for benefits and policies diverge increasingly. Likely, the southern North Sea will be re-zoned as riparian countries dedicate increasing sea space for offshore wind energy generation - with uncertain consequences for the system's environmental status. We review available observational and model data (predominantly from the southeastern North Sea region) to identify and describe effects of natural variability, of secular changes, and of human impacts on the North Sea ecosystem, and outline developments in the next decades in response to environmental legislation, and in response to

  3. SEA/WOMAN

    OpenAIRE

    Furse, Anna F. D.

    2011-01-01

    A new laboratory research performance by Anna Furse, Athletes of the Heart, UK) in collaboration with Maja Mitic (DAH Teatar, Serbia) and Antonella Diana (Teatret OM, Denmark) based on Henrik Ibsen's 'The lady from the sea' (1888). The project is an AHRC/ACE funded project as part of the Pinter Centre for Performance and Creative Writing's Fractured Narratives project. It has been touring in the UK and to Beirut, Lebanon.

  4. SEA/WOMAN

    OpenAIRE

    Furse, Anna F. D.

    2011-01-01

    A new laboratory research performance by Anna Furse, Athletes of the Heart, UK) in collaboration with Maja Mitic (DAH Teatar, Serbia) and Antonella Diana (Teatret OM, Denmark) based on Henrik Ibsen's 'The lady from the sea' (1888).\\ud \\ud The project is an AHRC/ACE funded project as part of the Pinter Centre for Performance and Creative Writing's Fractured Narratives project. It has been touring in the UK and to Beirut, Lebanon.

  5. Sea Basing Logistiek

    Science.gov (United States)

    2007-11-01

    iets wat nu voor zware goederen niet mogeljk is met de middelen binnen de Nederlandse krijgsmachit. Nederland heeft bijvoorbeeld (nog) geen specifieke...weer gevechtsklaar zijn. Nederlandse troepen voeren de reconstitute fase in het algemeen uit in Nederland . [Kang&Gue] A special concern in sea based...besluit Nederland zelf in te grijpen. De Nederlandse vredesmissie bevindt zich nabij de kust. maar ver van de grens met buurlanden. De operatie kan niet

  6. Armada puts to sea

    Energy Technology Data Exchange (ETDEWEB)

    Esau, I.

    1995-04-01

    This article describes the operational success of British Gas in exploiting the Armada gas field. Armada consists of three separate reservoirs (Fleming, Drake and Hawkins) and lies in the central North Sea. British Gas has successfully exploited this field on behalf of a group of co-venturers. This article describes the economic, technical and political difficulties faced by the company in operating this innovative method of management. (UK)

  7. Dead Sea rhodopsins revisited.

    Science.gov (United States)

    Bodaker, Idan; Suzuki, Marcelino T; Oren, Aharon; Béjà, Oded

    2012-12-01

    The Dead Sea is a unique hypersaline ecosystem with near toxic magnesium levels (∼2 M), dominance of divalent cations and a slightly acidic pH. Previously, we reported a haloarchaeon related to Halobacterium salinarum to dominate in a microbial bloom that developed in 1992 in the upper water layers of the lake following massive freshwater runoff. Whether this clade also dominated an earlier bloom in 1980-1982 cannot be ascertained as no samples for cultivation-independent analysis were preserved. The presence of the light-driven proton pump bacteriorhodopsin was reported in the 1980-1982 bloom of prokaryotes that had developed in the Dead Sea. To test the hypothesis that bacteriorhodopsin proton pumping may play a major role in determining what type of haloarchaea may dominate in specific bloom conditions, we compared rhodopsin genes recovered from Dead Sea biomass collected in different periods with genes coding for retinal proteins in isolated haloarchaea. Novel bacteriorhodopsin and sensory rhodopsin genes were found in samples collected in 2007 and 2010. The fact that no rhodopsin genes were recovered from samples collected during the 1992 bloom, which was dominated by a single species, suggests that different clades were present in the 1980-1982 and 1992 blooms, and that bacteriorhodopsin proton pumping did not necessarily play a determinative role in the dominance of specific halophiles in the blooms.

  8. Megaturbidite triggered by the ad 365 Cretan earthquake in the Mediterranean Sea

    Science.gov (United States)

    Polonia, Alina; Bonatti, Enrico; Camerlenghi, Angelo; Gasperini, Luca; Lucchi, Renata; Panieri, Giuliana

    2013-04-01

    Destructive earthquakes/tsunamis have affected repeatedly the circum Mediterranean highly populated coastal regions. A record of these past events can be provided by large-volume turbidites or megaturbidites, detected in the marine sedimentary record (Polonia et al., 2012). Megaturbidites have been identified in the Ionian basin (central Mediterranean) that is located between two tectonically active subduction zones (i.e. the Calabrin Arc to the North and the Hellenic Arc to the East). The uppermost megabed, has been named "Homogenite" (Kastens and Cita, 1981) or "Augias turbidite" (Hieke, 1984). Its well defined stratigraphic position, above the regional marker sapropel bed S1, has been interpreted as evidence that it was deposited in a single, basin-wide event capable to put into suspension simultaneously sediment at a basin-wide scale. Absence of absolute dating of the megabed and of a detailed chronostratigraphy of the deposits above and below the turbidite, have allowed a number of different correlations of this megaturbidite with the 3500 yr BP Minoan eruption of Santorini and related tsunamis in the Aegean Sea (Kastens and Cita, 1981), to the 7.600 ± 130 yr B.P. collapse of a flank of the Etna Volcano (Pareschi et al., 2006) or to the 365 earthquake in the Mediterranean (Vigliotti, 2008). Based on studies of sediment cores we collected from the Ionian seafloor (mineralogy, micropaleontology, elemental and isotopic geochemistry and radiocarbon dating), we show that the Homogenite/Augias turbidite (HAT), up to 20-25 m thick, was related to multi-source turbidity flows triggered by the 365 AD tsunami. We were able to reconstruct the different units deposited in response to the 365 AD Cretan earthquake/tsunami and the results confirm that the HAT is a unique instance of deep sea tsunami deposit. Backwash flows and related gravity-driven processes are the primary means of downslope sediment transport. An older similar deep sea megaturbidite was deposited in the

  9. Arctic Sea Ice

    Science.gov (United States)

    Stroeve, J. C.; Fetterer, F.; Knowles, K.; Meier, W.; Serreze, M.; Arbetter, T.

    2004-12-01

    Of all the recent observed changes in the Arctic environment, the reduction of sea ice cover stands out most prominantly. Several independent analysis have established a trend in Arctic ice extent of -3% per decade from the late 1970s to the late 1990s, with a more pronounced trend in summer. The overall downward trend in ice cover is characterized by strong interannual variability, with a low September ice extent in one year typically followed by recovery the next September. Having two extreme minimum years, such as what was observed in 2002 and 2003 is unusual. 2004 marks the third year in a row of substantially below normal sea ice cover in the Arctic. Early summer 2004 appeared unusual in terms of ice extent, with May a record low for the satellite period (1979-present) and June also exhibiting below normal ice extent. August 2004 extent is below that of 2003 and large reductions in ice cover are observed once again off the coasts of Siberia and Alaska and the Greenland Sea. Neither the 2002 or 2003 anomaly appeared to be strongly linked to the positive phase of the Arctic Oscillation (AO) during the preceding winter. Similarly, the AO was negative during winter 2003/2004. In the previous AO framework of Rigor et al (2002), a positive winter AO implied preconditioning of the ice cover to extensive summer decay. In this hypothesis, the AO does not explain all aspects of the recent decline in Arctic ice cover, such as the extreme minima of 2002, 2003 and 2004. New analysis by Rigor and Wallace (2004) suggest that the very positive AO state from 1989-1995 can explain the recent sea ice minima in terms of changes in the Arctic surface wind field associated with the previous high AO state. However, it is also reasonable to expect that a general decrease in ice thickness accompanying warming would manifest itself as greater sensitivity of the ice pack to wind forcings and albedo feedbacks. The decrease in multiyear ice and attendant changes in ice thickness

  10. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Science.gov (United States)

    Bachem, Paul E.; Risebrobakken, Bjørg; De Schepper, Stijn; McClymont, Erin L.

    2017-09-01

    The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial-interglacial variability. Here, we present high-resolution records of sea surface temperature (SST) and ice-rafted debris (IRD) in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  11. Bindin from a sea star

    OpenAIRE

    Patiño, Susana; Jan E. Aagaard; MacCoss, Michael J.; Swanson, Willie J.; Hart, Michael W

    2009-01-01

    The genetic basis for the evolution of development includes genes that encode proteins expressed on the surfaces of sperm and eggs. Previous studies of the sperm acrosomal protein bindin have helped to characterize the adaptive evolution of gamete compatibility and speciation in sea urchins. The absence of evidence for bindin expression in taxa other than the Echinoidea has limited such studies to sea urchins, and led to the suggestion that bindin might be a sea urchin-specific molecule. Here...

  12. Sea Salt Source Function over the Baltic Sea

    Science.gov (United States)

    Petelski, Tomasz; Makuch, Przemyslaw; Markuszewski, Piotr; Jankowski, Andrzej; Zieliński, Tymon

    2013-04-01

    Studies of production and transport of aerosol over the sea are very important for many areas of knowledge. Marine aerosol emitted from the sea surface helps to clean the boundary layer from other aerosol particles. The emitted droplets do not dry out in the highly humid surface layer air and because of their sizes most of them are deposited quickly at the sea surface. Therefore, marine aerosol has many features of rain i.e. the deposition in the marine boundary layer in high wind events is controlled not only by the "dry" processes but also by the "wet" scavenging. While many cruises conducted on board S/Y Oceania, we collected many data which were used to calculate sea salt source function over the Baltic Sea. Our cruises held between 2009 and 2012. Measurements were carried out using gradient method. For this method we used Laser Particle Counter (PMS model CSASP-100_HV) placed on one oft the mast of S/Y Oceania. Measurements were performed on five different levels around sea level: 8, 11, 14, 17 and 20 meters. Based on the averaged vertical concentration, profiles were calculated, using Monin-Obuchow theory, vertical sea spray fluxes in the near water layer. Based on fluxes calculated from vertical concentration profiles was calculated sea salt source function over the Baltic Sea. This function gives emission for different particle size, depending on environmental parameters. Emission of sea spray depends of the size of energy lost by the wind waves in process of collapse. Acknowledgements: The support for this study was provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBałtyk founded by European Union through European Regional Development Fund contract No. POIG 01.01.02-22-011/09.

  13. Experiencing the Full Research Process at Sea Education Association (SEA)

    Science.gov (United States)

    Harris, S. E.; Joyce, P.; Jaroslow, G.; Graziano, L.; Lea, C.; Witting, J.; Bower, A.

    2003-12-01

    While some undergraduate research experiences include only a small piece of the research process, students attending Sea Education Association's SEA Semester complete all aspects of oceanographic research in an intensive 12 week program that earns a full semester's credit. In the first half of the program, students read and discuss background literature on a subject, ask questions, pose hypotheses, and develop a written research proposal, which they defend orally. The second half of the course takes place at sea on one of SEA's state-of-the-art oceanographic research vessels where students carry out their sampling plans, analyze samples and data, write a final paper and present their results before the vessel reaches port, completing the course. At sea, students participate in sample collection and analysis for all student projects in addition to learning the general oceanography along their cruise track. This structure exposes students to the realities of research from start to finish and allows them to take full ownership of their projects. In addition to honing writing, public speaking, and problem-solving skills, students learn that research requires dedication, flexibility, and creativity, particularly when their results are unexpected or negate their hypothesis. SEA's undergraduate research program has been developing since 1971. Over that time, SEA has collected an extensive historical oceanographic database in the western Atlantic and Caribbean, plus Pacific data since 2001. This database is available to both students and outside research scientists. Collaborations with scientists outside SEA enhance the student experience and help facilitate oceanographic research by providing "ship-of-opportunity" sampling in remote locations. SEA Semester provides an excellent model for undergraduate research experiences with over 5000 alumni, about 30% of whom enter graduate school. About half the students in SEA's undergraduate programs are non-science majors. Although

  14. Constraints on the neodymium (Nd) oceanic cycle in the Mediterranean Sea using a high resolution coupled model

    Science.gov (United States)

    Ayache, Mohamed; Jeandel, Catherine; Dutay, Jean-claude; Arsouze, Thomas

    2015-04-01

    Neodymium isotopic composition (Nd IC) is a tracer of oceanic circulation and lithogenic inputs to the ocean. An extensive compilation of published Nd isotopic values was realized in order to establish a database and a map of ɛNd and Nd concentrations characterizing all the Mediterranean margins. This was built based on different kinds of samples: riverine solid discharge deposited on the shelf, sedimentary material collected along the margins and geological material above or close to an oceanic margin (following Jeandel et al., 2007). The margin Nd isotopic signatures vary from non-radiogenic values around the Gulf of Lions (Nd IC values between -11.5 and -10), to radiogenic values around the Aegean and the Levantine sub-basins (Nd IC up to +6). Such West-East variation was also observed in the seawater data, which are becoming more radiogenic along the eastward circulation in the Mediterranean Sea (Tachikawa et al., 2004). The Nd budget proposed by these authors raised the hypothesis that the exchange of Nd along the margins could play a significant role in driving the oceanic distribution of this tracer. On a more global scale, it was further demonstrated and modelled that dissolved/particulate exchanges between continental margin sediments and open ocean (termed boundary exchange, BE), could be the dominant source-sink terms that determine the distribution of neodymium isotopes in the global ocean (Lacan and Jeandel, 2005a, Arsouze et al 2009). But this global scale study with it low-resolution configuration ORCA2 (2° of horizontal resolution) could not resolve many local and regional-scale features Our purpose is to test this hypothesis for the first time in the Mediterranean Sea by using a high resolution regional coupled model (1/12° of horizontal resolution). In a first approach we considered that boundary exchange is the only term governing Nd distribution in the Mediterranean Sea (other sources have been neglected). This aimed to validate the "Boundary

  15. Waves in the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    or change. If ini- tially, only a thin layer of air close to the water surface matters in the mo- mentum transfer from wind to water, afterwards with strong winds, a layer of air upto say 15 to 30 metres comes Small sand waves formed on a seashore due... it breaks with a heading wind or on a beach). Consider an open sea of say 1000 square kilometres wherein billions of 'pushes' and 'pulls' happen over tens of hours, causing uncountable number of waves and wave groups of various types moving in different...

  16. Polarimetric signatures of sea ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Skriver, Henning; Pedersen, Leif Toudal

    1995-01-01

    Polarimetric SAR data of sea ice have been acquired by the Danish polarimetric SAR (EMISAR) during a mission at the Greenland Sea in August 1994. Video recordings from a low-altitude acquisition have been used for interpretation of the SAR data. Also, ERS-1 SAR data and NOAA AVHRR-data have been...

  17. NOAA NDBC SOS - sea_floor_depth_below_sea_surface

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have sea_floor_depth_below_sea_surface data. Because of the nature of SOS...

  18. EASE-Grid Sea Ice Age

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides weekly estimates of sea ice age for the Arctic Ocean from remotely sensed sea ice motion and sea ice extent. The ice age data are derived from...

  19. Sea modeling and rendering

    Science.gov (United States)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  20. Modelling sea ice dynamics

    Science.gov (United States)

    Murawski, Jens; Kleine, Eckhard

    2017-04-01

    Sea ice remains one of the frontiers of ocean modelling and is of vital importance for the correct forecasts of the northern oceans. At large scale, it is commonly considered a continuous medium whose dynamics is modelled in terms of continuum mechanics. Its specifics are a matter of constitutive behaviour which may be characterised as rigid-plastic. The new developed sea ice dynamic module bases on general principles and follows a systematic approach to the problem. Both drift field and stress field are modelled by a variational property. Rigidity is treated by Lagrangian relaxation. Thus one is led to a sensible numerical method. Modelling fast ice remains to be a challenge. It is understood that ridging and the formation of grounded ice keels plays a role in the process. The ice dynamic model includes a parameterisation of the stress associated with grounded ice keels. Shear against the grounded bottom contact might lead to plastic deformation and the loss of integrity. The numerical scheme involves a potentially large system of linear equations which is solved by pre-conditioned iteration. The entire algorithm consists of several components which result from decomposing the problem. The algorithm has been implemented and tested in practice.

  1. Lithospheric Response of the Anatolian Plateau in the Realm of the Black Sea and the Eastern Mediterranean

    Science.gov (United States)

    Ergun, Mustafa

    2016-04-01

    The Eastern Mediterranean and the Middle East make up the southern boundary of the Tethys Ocean for the last 200 Ma by the disintegration of the Pangaea and closure of the Tethys Ocean. It covers the structures: Hellenic and Cyprus arcs; Eastern Anatolian Fault Zone; Bitlis Suture Zone and Zagros Mountains. The northern boundary of the Tethys Ocean is made up the Black Sea and the Caspian Sea, and it extends up to Po valley towards the west (Pontides, Caucasus). Between these two zones the Alp-Himalayan orogenic belt is situated where the Balkan, Anatolia and the Iran plateaus are placed as the remnants of the lost Ocean of the Tethys. The active tectonics of the eastern Mediterranean is the consequences of the convergence between the Africa, Arabian plates in the south and the Eurasian plate in the north. These plates act as converging jaws of vise forming a crustal mosaic in between. The active crustal deformation pattern reveals two N-S trending maximum compression or crustal shortening syntaxes': (i) the eastern Black Sea and the Arabian plate, (ii) the western Black Sea and the Isparta Angle. The transition in young mountain belts, from ocean crust through the agglomeration of arc systems with long histories of oceanic closures, to a continental hinterland is well exemplified by the plate margin in the eastern Mediterranean. The boundary between the African plate and the Aegean/Anatolian microplate is in the process of transition from subduction to collision along the Cyprus Arc. Since the Black Sea has oceanic lithosphere, it is actually a separate plate. However it can be considered as a block, because the Black Sea is a trapped oceanic basin that cannot move freely within the Eurasian Plate. Lying towards the northern margin of orogenic belts related to the closure of the Tethys Ocean, it is generally considered to be a result of back-arc extension associated with the northward subduction of the Tethyan plate to the south. Interface oceanic lithosphere at

  2. SeaPort-e Workshop

    Science.gov (United States)

    2014-08-01

    aquilent.com 22 QUESTIONS?? 23 Back-up 24 Program Evolution Category SeaPort Original (2001 – 2004) SeaPort-Enhanced (2004...Function = Industry User Function External System Interfaces: Create Purchase Request (Navy ERP ) Receive CAR Data (FPDS-NG) Receive Award Documents (EDA) Receive Award Data (SPS)

  3. Her Husband Is at Sea

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Out in the sea of China are Chinese offshore oil workers. They battle against wind, waves, loneliness and monotony. Their profession requires not only bravery and endurance from the employees themselves, but also from their spouses. It is because of the wives’support that the husbands can work at sea. This,for women, means double family responsibilities, loneliness, worries and endless waiting.

  4. The Law of the Sea

    Science.gov (United States)

    Levy, Jean-Pierre

    1978-01-01

    Recounts problems related to the law of the sea and suggests that these problems could be dealt with in the classroom in an interdisciplinary manner. Problems include pollution control, fishing rights, development of deep sea mineral deposits, and shore access. (Author/DB)

  5. Plastic in North Sea Fish

    NARCIS (Netherlands)

    Foekema, E.M.; Gruijter, de C.; Mergia, M.T.; Franeker, van J.A.; Murk, A.J.; Koelmans, A.A.

    2013-01-01

    To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, wh

  6. Sea level and climate variations

    NARCIS (Netherlands)

    Oerlemans, J.

    1985-01-01

    Review paper, ESA Symposium on Application of Satellite Data to Climate Modelling. Alpbach (Austria) Sea level is an essential component of the climate system, on which many human activities in the coastal zone depend. Climate variations leading to changes in relative sea level are

  7. The environmental state at sea

    NARCIS (Netherlands)

    Tatenhove, van J.P.M.

    2016-01-01

    Seas and oceans are confronted with a plethora of environmental problems, caused by land-based activities (agriculture, industries, and ports) and by maritime activities (such as shipping, fishing, oil and gas drilling, tourism, and navigational dredging). Environmental problems at sea challenge the

  8. Sea Level Rise Data Discovery

    Science.gov (United States)

    Quach, N.; Huang, T.; Boening, C.; Gill, K. M.

    2016-12-01

    Research related to sea level rise crosses multiple disciplines from sea ice to land hydrology. The NASA Sea Level Change Portal (SLCP) is a one-stop source for current sea level change information and data, including interactive tools for accessing and viewing regional data, a virtual dashboard of sea level indicators, and ongoing updates through a suite of editorial products that include content articles, graphics, videos, and animations. The architecture behind the SLCP makes it possible to integrate web content and data relevant to sea level change that are archived across various data centers as well as new data generated by sea level change principal investigators. The Extensible Data Gateway Environment (EDGE) is incorporated into the SLCP architecture to provide a unified platform for web content and science data discovery. EDGE is a data integration platform designed to facilitate high-performance geospatial data discovery and access with the ability to support multi-metadata standard specifications. EDGE has the capability to retrieve data from one or more sources and package the resulting sets into a single response to the requestor. With this unified endpoint, the Data Analysis Tool that is available on the SLCP can retrieve dataset and granule level metadata as well as perform geospatial search on the data. This talk focuses on the architecture that makes it possible to seamlessly integrate and enable discovery of disparate data relevant to sea level rise.

  9. Scaling the Baltic Sea environment

    DEFF Research Database (Denmark)

    Larsen, Henrik Gutzon

    2008-01-01

    The Baltic Sea environment has since the early 1970s passed through several phases of spatial objectification in which the ostensibly well-defined semi-enclosed sea has been framed and reframed as a geographical object for intergovernmental environmental politics. Based on a historical analysis...

  10. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    P. E. Bachem

    2017-09-01

    Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  11. Chartering the high seas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Far from being a standard exercise, the transportation of coal by sea involves different players and procedures depending on the buyers and the sellers own strategy. This article, extracted from a new report by Drewry Shipping Consultants, identifies the strategies of the main players in the seaborne coal trade. In the coking coal market there is a long established preference for direct producer consumer purchase contracts, with the buyer undertaking the trading function, rather than purchasing through third parties. However, trading companies play a more important role in the steam coal market, acting either as principals or agents - or in some cases both. Both steam and coking coal are contracted mainly on a long-term basis. This guarantees supplies form sources which offer the optimum grades of coal for their plant. Diversity of supply is also an issue in case there are problems in obtaining the chosen coal. Shipping practices in Japan, Europe and elsewhere are examined. 2 figs., 3 tabs.

  12. Arctic Sea Ice Predictability and the Sea Ice Prediction Network

    Science.gov (United States)

    Wiggins, H. V.; Stroeve, J. C.

    2014-12-01

    Drastic reductions in Arctic sea ice cover have increased the demand for Arctic sea ice predictions by a range of stakeholders, including local communities, resource managers, industry and the public. The science of sea-ice prediction has been challenged to keep up with these developments. Efforts such as the SEARCH Sea Ice Outlook (SIO; http://www.arcus.org/sipn/sea-ice-outlook) and the Sea Ice for Walrus Outlook have provided a forum for the international sea-ice prediction and observing community to explore and compare different approaches. The SIO, originally organized by the Study of Environmental Change (SEARCH), is now managed by the new Sea Ice Prediction Network (SIPN), which is building a collaborative network of scientists and stakeholders to improve arctic sea ice prediction. The SIO synthesizes predictions from a variety of methods, including heuristic and from a statistical and/or dynamical model. In a recent study, SIO data from 2008 to 2013 were analyzed. The analysis revealed that in some years the predictions were very successful, in other years they were not. Years that were anomalous compared to the long-term trend have proven more difficult to predict, regardless of which method was employed. This year, in response to feedback from users and contributors to the SIO, several enhancements have been made to the SIO reports. One is to encourage contributors to provide spatial probability maps of sea ice cover in September and the first day each location becomes ice-free; these are an example of subseasonal to seasonal, local-scale predictions. Another enhancement is a separate analysis of the modeling contributions. In the June 2014 SIO report, 10 of 28 outlooks were produced from models that explicitly simulate sea ice from dynamic-thermodynamic sea ice models. Half of the models included fully-coupled (atmosphere, ice, and ocean) models that additionally employ data assimilation. Both of these subsets (models and coupled models with data

  13. Sea Surface Temperature Climate Data Record for the North Sea and Baltic Sea

    DEFF Research Database (Denmark)

    Høyer, Jacob L.; Karagali, Ioanna

    2016-01-01

    A 30-yr climate data record (CDR) of sea surface temperature (SST) has been produced with daily gap-free analysis fields for the North Sea and the Baltic Sea region from 1982 to 2012 by combining the Pathfinder AVHRR satellite data record with the Along-Track Scanning Radiometer (ATSR) Reprocessing...... observations on average. Validation against independent in situ observations shows a very stable performance of the data record, with a mean difference of -0.06 °C compared to moored buoys and a 0.46 °C standard deviation of the differences. The mean annual biases of the SST CDR are small for all years......, with a negligible temporal trend when compared against drifting and moored buoys. Analysis of the SST CDR reveals that the monthly anomalies for the North Sea, the Danish straits, and the central Baltic Sea regions show a high degree of correlation for interannual and decadal time scales, whereas the monthly...

  14. Role of sea ice in air-sea exchange and its relation to sea fog

    Institute of Scientific and Technical Information of China (English)

    解思梅; 包澄澜; 姜德中; 邹斌

    2001-01-01

    Synchronous or quasi-synchronous stereoscopic sea-ice-air comprehensive observation was conducted during the First China Arctic Expedition in summer of 1999. Based on these data, the role of sea ice in sea-air exchange was studied. The study shows that the kinds, distribution and thickness of sea ice and their variation significantly influence the air-sea heat exchange. In floating ice area, the heat momentum transferred from ocean to atmosphere is in form of latent heat; latent heat flux is closely related to floating ice concentration; if floating ice is less, the heat flux would be larger. Latent heat flux is about 21 23.6 W*m-2, which is greater than sensible heat flux. On ice field or giant floating ice, heat momentum transferred from atmosphere to sea ice or snow surface is in form of sensible heat. In the floating ice area or polynya, sea-air exchange is the most active, and also the most sensible for climate. Also this area is the most important condition for the creation of Arctic vapor fog. The heat exchange of a large-scale vapor fog process of about 500000 km2 on Aug. 21 22,1999 was calculated; the heat momentum transferred from ocean to air was about 14.8×109 kW. There are various kinds of sea fog, radiation fog, vapor fog and advection fog, forming in the Arctic Ocean in summer. One important cause is the existence of sea ice and its resultant complexity of both underlying surface and sea-air exchange.

  15. Sea surface temperature anomalies in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    . Further analysis has shown that the sea surface anomalies are well correlated to the anomalies of air temperature and latent heat flux values; whereas they are least correlated to the anomalies of wind stress and net radiation values, except over...

  16. Sea otters and Alaska's developing sea farming industry

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this paper are to give an overview of the current status of the industry in Alaska, identify potential problems between mariculture and sea otters...

  17. Chemical oceanography of the Arabian Sea Part iv Laccadive sea

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Moraes, C.; Kureishy, T.W.; Sankaranarayanan, V.N.; Jana, T.K.; Naqvi, S.W.A.; Rajagopal, M.D.

    Patterns of distribution of nutrients and nutrients-oxygen relationships are similar to those observed in other parts of the Arabian Sea High magnesium and low fluoride concentrations in the water indicate probable loss of the latter as insoluble ion...

  18. Iridium in sea-water.

    Science.gov (United States)

    Fresco, J; Weiss, H V; Phillips, R B; Askeland, R A

    1985-08-01

    Iridium in sea-water has been measured (after isolation from the saline matrix by reduction with magnesium) by neutron bombardment, radiochemical purification and high-resolution gamma-ray spectroscopy. The concentration obtained in a Pacific coastal water was 1.02 +/- 0.26 x 10(-14) g per g of sea-water. At such extremely low concentrations, seawater is an extremely unlikely source for anomalously high iridium concentrations measured in the Cretaceous-Tertiary boundary layer of deep-sea sediments.

  19. Iridium in sea-water

    Energy Technology Data Exchange (ETDEWEB)

    Fresco, J.; Weiss, H.V.; Phillips, R.B.; Askeland, R.A.

    1985-08-01

    Iridium in sea-water has been measured (after isolation from the saline matrix by reduction with magnesium) by neutron bombardment, radiochemical purification and high resolution ..gamma..-ray spectroscopy. The concentration obtained in a Pacific coastal water was 1.02 +- 0.26 x 10/sup 14/ g per g of sea-water. At such extremely low concentrations, seawater is an extremely unlikely source for anomalously high iridium concentrations measured in the Cretaceous-Tertiary boundary layer of deep-sea sediments.

  20. How SEA can inform lenders

    DEFF Research Database (Denmark)

    Banhalmi-Zakar, Zsuzsa; Larsen, Sanne Vammen

    SEA can be a powerful tool to improve decision-making for plans, policies and programmes, but it can also be a useful for banks. SEA can help lenders address the reputational risks they are exposed to through financing projects that may have a negative impact on the environment and it can also help......, such as in the credit policies. It was also found that in some cases lenders become involved in project planning at a very early stage, when projects are conceptualized, and certainly before formal approval is sought from relevant authorities and an EIA is conducted. This suggests that SEA can be a useful tool...

  1. The politics of SEA indicators

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    2013-01-01

    The use of indicators is not only technical and science-led, but also a value-laden social process, and thus concerns public participation, political judgment and decision-making. This article approaches the Chinese SEA indicator system from a science-policy interface and aims at: 1) contributing...... to the general recognition of indicators functioning at science-policy interfaces in SEA, and 2) analysing, through a Chinese case-study, to what extent national guidelines mediate the science-policy interaction. The overall finding is a strong emphasis on technical/science aspects found in the Chinese SEA...

  2. Summer sea ice characteristics of the Chukchi Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    During August 1999, we investigated sea ice characteristics; its distribution, surface feature, thickness, ice floe movement, and the temperature field around inter-borders of air/ice/seawater in the Chukchi Sea. Thirteen ice cores were drilled at 11 floe stations in the area of 72°24′ 77°18′N, 153°34′ 163°28′W and the ice core structure was observed. From field observation, three melting processes of ice were observed; surface layer melting, surface and bottom layers melting, and all of ice melting. The observation of temperature fields around sea ice floes showed that the bottom melting under the ice floes were important process. As ice floes and open water areas were alternately distributed in summer Arctic Ocean; the water under ice was colder than the open water by 0.4 2.8℃. The sun radiation heated seawater in open sea areas so that the warmer water went to the bottom when the ice floes move to those areas. This causes ice melting to start at the bottom of the ice floes. This process can balance effectively the temperature fluctuating in the sea in summer. From the crystalline structure of sea ice observed from the cores, it was concluded that the ice was composed of ice crystals and brine-ice films. During the sea ice melting, the brine-ice films between ice crystals melted firstly; then the ice crystals were encircled by brine films; the sea ice became the mixture of ice and liquid brine. At the end of melting, the ice crystals would be separated each other, the bond between ice crystals weakens and this leads to the collapse of the ice sheet.

  3. A multi-model ensemble view of winter heat flux dynamics and the dipole mode in the Mediterranean Sea

    Science.gov (United States)

    Liguori, Giovanni; Di Lorenzo, Emanuele; Cabos, William

    2017-02-01

    Changes in surface heat fluxes affect several climate processes controlling the Mediterranean climate. These include the winter formation of deep waters, which is the primary driver of the Mediterranean Sea overturning circulation. Previous studies that characterize the spatial and temporal variability of surface heat flux anomalies over the basin reveal the existence of two statistically dominant patterns of variability: a monopole of uniform sign and an east-west dipole of opposite signs. In this work, we use the 12 regional climate model ensemble from the EU-FP6 ENSEMBLES project to diagnose the large-scale atmospheric processes that control the variability of heat fluxes over the Mediterranean Sea from interannual to decadal timescales (here defined as timescales > 6 year). Our findings suggest that while the monopole structure captures variability in the winter-to-winter domain-average net heat flux, the dipole pattern tracks changes in the Mediterranean climate that are connected to the East Atlantic/Western Russia (EA/WR) atmospheric teleconnection pattern. Furthermore, while the monopole exhibits significant differences in the spatial structure across the multi-model ensemble, the dipole pattern is very robust and more clearly identifiable in the anomaly maps of individual years. A heat budget analysis of the dipole pattern reveals that changes in winds associated with the EA/WR pattern exert dominant control through both a direct effect on the latent heat flux (i.e., wind speed) and an indirect effect through specific humidity (e.g., wind advection). A simple reconstruction of the heat flux variability over the deep-water formation regions of the Gulf of Lion and the Aegean Sea reveals that the combination of the monopole and dipole time series explains over 90 % of the heat flux variance in these regions. Given the important role that surface heat flux anomalies play in deep-water formation and the regional climate, improving our knowledge on the dynamics

  4. SMOS Sea Surface Salinity Validation in the South China Sea

    Science.gov (United States)

    Ren, Yongzheng; Li, Xiaoming; Dong, Qing

    2013-01-01

    In November 2009, the European Space Agency (ESA) launched the first soil moisture and ocean salinity (SMOS) satellite, which represented the first use of spaceborne remote sensing tools to probe global sea surface salinity (SSS). The SMOS satellite carries a microwave imaging radiometer with aperture synthesis (MIRAS) for detection in the microwave L-band as the only payload. The MIRAS instrument is expected to provide a global SSS distribution with a spatial resolution of approximately 100 km and an accuracy of 0.1-0.2 practical salinity units (psu). The South China Sea is semi-enclosed, and the sea conditions are relatively complex. The suitability of ESA SMOS salinity products for the South China Sea has not been validated. Therefore, using SSS data measured during an expedition in the South China Sea, which was sponsored by China Natural Science Foundation and conducted in the fall of 2011, this paper validated the SSS products released by ESA, which were retrieved using three sea surface roughness models. To analyze the effect of the spatial resolution on the weekly average SMOS SSS distribution, the weekly average salinity data were averaged to reduce the spatial resolution to 0.25 ° x 0.25°. These average data were then compared to the measured data, followed by an analysis of the error variation. In addition, the effects of the orbital track (ascending or descending) on the SSS retrieval were analyzed.

  5. Towards Good Order at Sea

    DEFF Research Database (Denmark)

    Mandrup, Thomas; Vreÿ, Francois

    . The problems originating from the resultant “bad order at sea” can be directly felt on land, when smuggling, terrorism and related criminal activities operate more or less unhindered. The book provides an important mapping of the challenges preventing good order at sea off the African coast and East Africa......This book addresses a timely and important theme in the debate on how to create good governance at sea in general, but specifically in the Western Indian Ocean. In a security milieu where the number of piracy attacks originating from Somalia has decreased, there is an urgent need to address...... structural problems facing attempts to create and maintain good order at sea off East Africa. As mentioned in one of the chapters, the most secure place for a criminal in East Africa to be is at sea, because most African littoral states have only limited capacity to police their territorial waters...

  6. USGS Sea Ice Email Script

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Daily sea ice imagery and charting benefits logistics and navigational planning in the Alaskan Arctic waters, yet access to these data often requires high bandwidth...

  7. Doppler characteristics of sea clutter.

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01

    Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

  8. A Can of Sea Worms

    Science.gov (United States)

    Zinn, Donald J.

    1977-01-01

    A comprehensive discussion of the free-living worms that inhabit the beaches and subtidal bottoms of the Cape Cod shoreline is presented. Methods for the location, collection, preservation, and identification of sea worms are identified. (BT)

  9. Temperature measurement in the sea

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnamacharyulu, R.J.; Rao, L.V.G.

    ), their advantages and limitations are also touched upon. Calibration of various instruments used for temperature measurement in the sea and the special setup/facilities needed for this purpose are also discussed...

  10. Sea otter studies in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The final objective of the present Fish and Wildlife sea otter program is to learn enough of the ecology, population, reproductive potential, and requirements in...

  11. Spirulina culture in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Materassi, R.; Tredici, M.; Waldemaro, B.

    1984-01-01

    Laboratory experiments using small raceway ponds have shown that Spirulina maxima can be adapted easily to grow in sea-water supplemented with nitrate, phosphate, bicarbonate, and Fe-EDTA. To prevent precipitate formation, phosphate was supplied by diffusion through a dialysis membrane; the amount of Na-bicarbonate added was low (100 ppm) and the pH was kept in the range 8.6 - 8.8 by bubbling CO/sub 2/ into the culture. No significant differences have been noticed in productivity or in the chemical composition of the biomass between cultures in sea-water and in the standard bicarbonate medium. Cultures subjected to light/dark cycles of 12/12 hours showed a higher respiration rate in sea-water than in the bicarbonate medium. The higher weight loss in the sea-water medium in the dark was counterbalanced by an increased synthesis of carbohydrates during the light period. 9 references.

  12. Black Sea Bass genetic connectivity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microsatellite analysis of black sea bass was undertaken to determine magnitude and direction of mixing of black seabass across the Hatteras boundary, as well as...

  13. Sea Turtle Acoustic Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Acoustic tags were attached to sea turtles captured in various fishing gear and the animals are either actively or passively tracked

  14. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  15. Dynamic Topography of the Bering Sea

    Science.gov (United States)

    2011-01-01

    Bering Sea. Comparisons also indicate that MDT estimates derived from the latest Gravity Recovery and Climate Experiment geoid model have more in common...with the presented sea surface topography than with the MDTs based on earlier versions of the geoid . The presented MDT will increase the accuracy of...estimating the geoid in the Bering Sea. 15. SUBJECT TERMS dynamic topography, sea surface height, Bering Sea, 4DVar 16. SECURITY CLASSIFICATION OF: a

  16. Alien seas oceans in space

    CERN Document Server

    Lopes, Rosaly

    2013-01-01

    In the early days of planetary observation, oceans were thought to exist in all corners of the Solar System. Carbonated seas percolated beneath the clouds of Venus. Features on the Moon's surface were given names such as "the Bay of Rainbows” and the "Ocean of Storms." With the advent of modern telescopes and spacecraft exploration these ancient concepts of planetary seas have been replaced by the reality of something even more exotic. Alien Seas serves up the current research, past beliefs, and new theories to offer a rich array of the "seas" on other worlds. It is organized by location and by the material composing the oceans under discussion, with expert authors penning chapters on their  specialty. Each chapter features new original art depicting alien seas, as well as the latest ground-based and spacecraft images. With the contributors as guides, readers can explore the wild seas of Jupiter's watery satellite Europa, believed similar in composition to battery acid. Saturn's planet-sized moon Titan see...

  17. The Appreciation of the Coastal Reconstruction Project of Public Landscape Architecture“Sea Organ”%公共景观建筑“海风琴”海岸改造工程评析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Croatia, which lies on the Aegean Sea, is known as the garden of Europe for its geographic beauty and long tradition of music. The Sea Organ is a landscape architectural program in Zadar, the fifth large city in Croatia, and it is the winner of the European City Public Space Award 2006 and a candidate of the European Union Prize--Mies van der Rohe Award. This work is an artistic practice that connects sea and land, and a work that displays the sounds of nature.%  位于爱琴海沿岸的克罗地亚是欧洲的后花园,它不但有着美轮美奂的地理风景,悠久的音乐文化传统也颇受世人关注。本案例——“海风琴”景观设计项目呈现给世界一场令人叹为观止的现代空间视听盛宴。“海风琴”景观设计项目位于克罗地亚的第五大城市扎达尔,曾荣获2006年欧洲城市公共空间奖,并当选2007年当代建筑欧洲联盟奖(密斯·凡·德·罗奖)初赛作品。本案通过艺术实践充分实现海洋和陆地的互通,成功引发自然和人类的视听双重共鸣,将自然的声音通过人工手法以一种全新的形式予以展现。

  18. Sea otter investigation, Amchitka Island, 1954, and proposed plan of research for sea otters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes a sea otter investigation on Amchitka Island during 1954 and a proposed plan of research for sea otters. The report covers capturing wild sea...

  19. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    Science.gov (United States)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  20. Toxic Algae and Early Warning Management in Yellow Sea and Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    Song; Lun; Song; Guangjun; Song; Yonggang; Xu; Xiaohong

    2014-01-01

    The research status of toxic algae in Yellow Sea and Bohai Sea are reviewed from the aspects of toxicity characteristics,toxic mechanism and early warning management,and the existing toxic algae and their toxicity in Yellow Sea and Bohai Sea are analyzed in the paper. The early warning level of toxic algae in Yellow Sea and Bohai Sea of China is put forward,and the research direction of shellfish poisoning in future is summarized.

  1. Magnetohydrodynamic sea water propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.

    1991-01-01

    An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.

  2. Magnetohydrodynamic sea water propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.

    1991-12-31

    An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.

  3. Dead sea asphalts: historical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

  4. Integrating out the Dirac sea

    Energy Technology Data Exchange (ETDEWEB)

    Karbstein, Felix

    2009-07-08

    We introduce a new method for dealing with fermionic quantum field theories amenable to a mean-field-type approximation. In this work we focus on the relativistic Hartree approximation. Our aim is to integrate out the Dirac sea and derive a no-sea effective theory'' with positive energy single particle states only. As the derivation of the no-sea effective theory involves only standard Feynman diagrams, our approach is quite general and not restricted to particular space-time dimensions. We develop and illustrate the approach in the ''large N'' limit of the Gross-Neveu model family in 1+1 dimensions. As the Gross-Neveu model has been intensely studied and several analytical solutions are known for this model, it is an ideal testing ground for our no-sea effective theory approach. The chiral Gross-Neveu model, also referred to as 1+1 dimensional Nambu-Jona-Lasinio model, turns out to be of particular interest. In this case, we explicitly derive a consistent effective theory featuring both elementary ''{pi} meson'' fields and (positive energy) ''quark'' fields, starting from a purely fermionic quantum field theory. In the second part of this work, we apply our approach to the Walecka model in 1+1 and 3+1 dimensions. As the Dirac sea caused considerable difficulties in attempts to base nuclear physics on field theoretic models like the Walecka model, mean-field calculations were typically done without the sea. We confront several of these mean-field theory results with our no-sea effective theory approach. The potential of our approach is twofold. While the no-sea effective theory can be utilized to provide new analytical insights in particular parameter regimes, it also sheds new light on more fundamental issues as the explicit emergence of effective, Dirac-sea induced multi-fermion interactions in an effective theory with positive energy states only. (orig.)

  5. Understanding the Amundsen Sea Low

    Science.gov (United States)

    McDonald, Adrian

    2016-04-01

    The Amundsen Sea Low (ASL) is a climatological low pressure system located between 170-300 ° E and 60-75°S and is a key component of the non-zonal climatological circulation at high southern latitudes. With reanalysis output identifying that climatologically the low in the Amundsen Sea is the deepest of three mean sea level pressure (MSLP) centres observed around Antarctica. The ASL strongly modulates West Antarctic climate with impacts on sea ice extent, temperature and precipitation, via its controlling influence on the variability of the meridional wind field. It has also been shown to have a significant influence on the atmospheric circulation in the Ross Sea region and to strongly modulate temperature and moisture advection over the Antarctic Peninsula. Previous work has demonstrated strong relationships between the depth of the ASL and cyclone densities in the region. However, interestingly a recent review identified that it is not easy to relate the storm density and depths of the cyclones to the climatological ASL, since the climatological location of the ASL does not occur at a clear maximum of storm activity. This study examines output from the ERA-interim reanalyses around Antarctica to further understand the contributors to the climatological pattern, partially in an effort to identify whether a more physically meaningful ASL depth index (normally simply defined as the monthly minimum MSLP) can be created. In this effort, storm track data derived from the ERA-Interim reanalysis and mean sea level pressure data bandpass filtered to accentuate synoptic scale variability are first examined. The contribution of persistent positive anomalies in the mean sea level pressure (defined as 8hPa positive anomalies from the climatological mean for a period of 5 days) in the region surrounding the Amundsen sea is also examined to identify whether blocking plays a role. Finally, the frequency of persistent negative anomalies (defined as a negative 8hPa occurring for

  6. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  7. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  8. Iodine emissions from the sea ice of the Weddell Sea

    Directory of Open Access Journals (Sweden)

    H. M. Atkinson

    2012-05-01

    Full Text Available Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to elucidate the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv, respectively were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  9. Iodine emissions from the sea ice of the Weddell Sea

    Directory of Open Access Journals (Sweden)

    H. M. Atkinson

    2012-11-01

    Full Text Available Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv respectively were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  10. Alone by the Sea

    Directory of Open Access Journals (Sweden)

    Zoran Ferić

    2015-06-01

    Full Text Available 1.At first the island is just a sign on a yellow board with a drawing of a vessel and the letters saying “Car Ferry,” then it is a grayish silhouette in the blue of the sea, and then, later still, an acquaintance working on the ferry, who just nods briefly in greeting. Jablanac, ferry port, its pleasant lobby, and then, from the upper deck, a giant rock approaching. That is the object of a year-long desire: the moment of stepping off the boat and smelling the rosemary, diesel and sheep droppings, seeing the sharp rocks looking at the Strait of Senj, coarse limestone in sharp opposition to the signs that say: Benvenuti, Welcome, Willkommen!At home, on the terrace, in the shade of the oleander, there’s no wish to eat. Only swimming trunks are put on and then, barefoot, without a towel or sun-tanning lotion, off to the beach.“Why won’t you eat something?” grandma asks.She knows that there’s an exciting world waiting out there, but she knows nothing of the details. All friends went on a boat trip. And suddenly one step from the shade of a path covered with oleanders and acacias leads into the burning sun of the afternoon. The light screams, just like children in the water, just like white objects that radiate as if there are some powerful light bulbs within. The feeling of freedom of someone who has just arrived in a foreign place and can now do anything. There’s no one familiar on the beach, they all got in the boat and left. The seafront leading to the camp is full of people, naked children with dirty faces licking ice cream, young families pushing strollers, groups of teenagers who have just woken up from their last night’s party. But there’s no one that must be greeted. The feeling of freedom that’s at the same time close to death. Suddenly, all paths are open. That there are no obligations or friends waiting, this afternoon, until they come back, is a complete boon.

  11. On The Black Sea Surozhian

    Science.gov (United States)

    Caraivan, Glicherie; Corneliu, Cerchia

    2016-04-01

    Some Black Sea researchers still support the idea of no other connection to the Mediterranean Sea between LGM and Karangatian Stage (Riss - Wurm). We try to clarify the source of these disagreements. C14 AMS age data (HERAS Project) made on undisturbed samples from a new Mamaia drilling hole where compared with the classical Black Sea stratigraphic schemes. A first transgressive event (Zone D) is found between 38.00 - 20.20 m depth. Zone D4 shows a fairly rapid rise of sea level, about 10 m below the present one indicating an inner shelf marine polyhaline environment. AMS age data show 14C ages between 53690 - 47359 y (MIS 1), corresponding to the "Surozhian Beds" of Popov. The "beach rock" from Zone E marks the decrease of the sea level after the maximum reached in Zone D4. Zone E mollusc shells AMS data, indicate 14C ages of 48724 - 44604 y, suggesting a long-time reworked material from the previous D4 zone sediments, and represents the beginning of the "regressive Tarkankutian" sequence.The Last Glacial Maximum (LGM) led to the retreat of the sea level down to about 100 m below the current one (27-17 ky BP), followed by an retreat of the shoreline to the present position. At the beginning of the Holocene - MIS 1 (8408-8132 cal. y BP), Black Sea brackish water level grew rapidly, up to -14 m below the present one (Zone F: 22, 57-20, 20 m). Zone F deposits could be correlated with the Bugazian strata. Then, a continuous rising of the Black Sea level is recorded up to a maximum of -2 m under the present one, about 6789 - 7063 cal. y BP, when a transgressive spurt ("Neolithic transgression") may have taken place. After that, given a weak Danubian sedimentary input, coastal erosion intensified. The coarse sandy sediments were reworked and pushed over the previous peat deposits, and suggest a classical "sedimentary regression", not a sea-level decrease. During the last 1.5 ky, sea level has risen towards the current one. Previous C14 dates from "Karangatian

  12. Vulnerability of marginal seas to sea level rise

    Science.gov (United States)

    Gomis, Damia; Jordà, Gabriel

    2017-04-01

    Sea level rise (SLR) is a serious thread for coastal areas and has a potential negative impact on society and economy. SLR can lead for instance to land loss, beach reduction, increase of the damage of marine storms on coastal infrastructures and to the salinization of underground water streams. It is well acknowledged that future SLR will be inhomogeneous across the globe, with regional differences of up to 100% with respect to global mean sea level (GMSL). Several studies have addressed the projections of SLR at regional scale, but most of them are based on global climate models (GCMs) that have a relatively coarse spatial resolution (>1°). In marginal seas this has proven to be a strong limitation, as their particular configurations require spatial resolutions that are not reachable by present GCMs. A paradigmatic case is the Mediterranean Sea, connected to the global ocean through the Strait of Gibraltar, a narrow passage of 14 km width. The functioning of the Mediterranean Sea involves a variety of processes including an overturning circulation, small-scale convection and a rich mesoscale field. Moreover, the long-term evolution of Mediterranean sea level has been significantly different from the global mean during the last decades. The observations of present climate and the projections for the next decades have lead some authors to hypothesize that the particular characteristics of the basin could allow Mediterranean mean sea level to evolve differently from the global mean. Assessing this point is essential to undertake proper adaptation strategies for the largely populated Mediterranean coastal areas. In this work we apply a new approach that combines regional and global projections to analyse future SLR. In a first step we focus on the quantification of the expected departures of future Mediterranean sea level from GMSL evolution and on the contribution of different processes to these departures. As a result we find that, in spite of its particularities

  13. GHRSST Level 4 DMI_OI North Sea and Baltic Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  14. How SEA can inform lenders

    DEFF Research Database (Denmark)

    Banhalmi-Zakar, Zsuzsa; Larsen, Sanne Vammen

    SEA can be a powerful tool to improve decision-making for plans, policies and programmes, but it can also be a useful for banks. SEA can help lenders address the reputational risks they are exposed to through financing projects that may have a negative impact on the environment and it can also help...... with identifying the financial incentives that ‘green’ projects attract. Although bank lending decisions apply to projects, examination of the lending practices of an Australian and a Hungarian bank have shown that decisions about the type of projects to target or avoid are also made at strategic level......, such as in the credit policies. It was also found that in some cases lenders become involved in project planning at a very early stage, when projects are conceptualized, and certainly before formal approval is sought from relevant authorities and an EIA is conducted. This suggests that SEA can be a useful tool...

  15. Coccidioidomycosis in southern sea otters

    Science.gov (United States)

    Thomas, Nancy J.; Pappagianis, Demosthenes; Creekmore, Lynn H.; Duncan, Ruth M.

    1994-01-01

    Disseminated coccidioidomycosis was diagnosed postmortem in six southern sea otters (Enhydra lutris nereis) found dying or dead along the Pacific Coast of California at San Luis Obispo County.  These otters were found during winter or summer 1992, 1993, and 1994.  Coccidioides immitis was identified by its morphology in tissue impression smears and by histopathology, and was confirmed by culture.  Positive serologic results were obtained from four of five sea otters tested.  The lungs, pleura, tracheobronchial lymph nodes, liver, and spleen were involved in each case.  There was meningeal involvement in half of the affected animals.  Coccidioidomycosis has been reported in a wild sea otter only once previously, in 1976, and that otter was also found on the coast of San Luis Obispo County.

  16. Mapping the deep sea floor

    DEFF Research Database (Denmark)

    Nielsen, Kristian Hvidtfelt

    By the early 20th century, oceanographers intensified their efforts to map the deep sea. The great depth of the Philippine Trench was first observed by the German Planet Expedition in 1912. During World War II, the US naval vessel Cape Johnson used directional echo-sounding to obtain a depth of 10......,497 m. In 1951, the Danish Galathea Deep Sea Expedition from 1950 to 1952 verified the result of the Cape Johnson sounding. Today, the greatest depth in the Philippine Trench is the Galathea Depth of 10,540 m. The Galathea Expedition produced several echograms of the deepest parts of the Philippine...... Trench in order to map its bathymetric features. The resulting maps are presented in this poster. Unlike many other contemporary developments in deep sea topography and cartography that were shaped by the Cold War, the Galathea maps of the Philippine Trench were intimately connected with the expedition...

  17. EXPERIMENTS OF SEA ICE SIMULATION

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-ying; ZHANG Xue-hong; YU Ru-cong; LIU Hai-long; YU Yong-qiang

    2005-01-01

    As a substitute for the original displaced pole grids, a simple rotated spherical coordinate system was introduced into the Community Sea Ice Model version 4(CSIM4), which is a component of the Community Climate System Model(CCSM) of the American National Center of Atmospheric Research(NCAR), to deal with the "pole problems".In the new coordinates, both the geographical North Pole and South Pole lie in the model equator and grid sizes near the polar region are more uniform.With reanalysis dataset of American National Centers for Environment Prediction(NCEP) and Levitus dataset without considering sub-mixed layer heat flux, the model was integrated for 100 years with thermodynamics process involved only in the former 49 years and both dynamic and thermodynamic processes involved in the left time.Inner consistency of model results was checked with no contradiction found.The results of last 10 years' model output were analyzed and it is shown that the simulated sea ice seasonal variation is rational whereas sea ice extent in the Barents Sea in winter is larger than that of observation.Numerical experiment on influence of sub-mixed layer heat flux was also carried out and it is shown that the sub-mixed layer heat flux can modulate seasonal variation of sea ice greatly.As a model component, the sea ice model with rotated spherical coordinates was coupled with other models (the oceanic general circulation model is the LASG/IAP Climate System Ocean Model(LICOM) with reduced grid, other models are components of NCAR CCSM2) forming a climate system model and its preliminary results were also given briefly.

  18. Black Sea coastal forecasting system

    Directory of Open Access Journals (Sweden)

    A. I. Kubryakov

    2012-03-01

    Full Text Available The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast.

  19. Sailing In Sea of Commerce

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The law of big fish swallowing little fish has expired when it comes to the era of new economy.What prevails nowadays in the sea of commerce is quick fish swallowing slow fish.In the Internet economy,small companies are not destined to lose to giants,but slow ones are doomed to become prey of their quick counterparts. The swiftly rising Yongkang Group has made a breakthrough in dental treatment by translating the law into practice.It is called"Law of the Sea."‘Law of the Sea’

  20. The surface circulation in the eastern basin of the Mediterranean Sea

    Science.gov (United States)

    Hamad, N.; Millot, C.; Taupier-Letage, I.

    2003-04-01

    The POEM-schema of the Atlantic Water (AW, http://ciesm.org/events/RT5-WaterMassAcronyms.pdf) circulation in the eastern basin of the Mediterranean Sea widely referred to nowadays (Robinson et al., 1991, completed by Robinson and Golnaraghi, 1993, and by Malanotte-Rizzoli et al., 1997) represents, in particular, a jet meandering offshore across the whole basin. No information is given on the southern part of the basin and no mention is made of a possible overall alongslope anticlockwise flow there, as suggested by a contemporaneous analysis of infrared satellite images (Le Vourch et al., 1992; Millot, 1992). A roughly similar controversy was elucidated in the western basin where such imagery was proven reliable. This has motivated the detailed analysis of daily and weekly composite images (about 1000) during the period 1996-2000, and of monthly composites available since 1985. Our analysis shows that AW circulates alongslope and anticlockwise around the whole basin, as indicated by Nielsen (1912) who considered the Coriolis effect as dominant. This circulation, which is permanent from Tunisia to Turkey, exists more or less temporarily in the Aegean, in the Ionian around Greece and in the Adriatic, due to the Etesians. However, a branch having spread for years (up to early 1998) from the channel of Sicily towards the northern Ionian before vanishing represents marked interannual (not seasonal) variability. Being unstable during most of its circuit, the AW flow generates mesoscale eddies which had not been correctly described before and which represent a relatively large amount of AW. Other eddies are known to be generated by orographic effects on the wind field, especially the Etesians. Both kinds of eddies play a fundamental role in spreading AW from alongslope towards the open basin. Although these eddies have characteristics almost specific to each subbasin and/or generation mechanism, the largest ones are anticyclonic, both kinds reach diameters of a few 100s km

  1. Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19 by multiple Soviet Union institutes (NODC Accession 0077413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19...

  2. 2010 USGS Lidar: Salton Sea (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS Salton Sea project encompasses a 5-kilometer buffer around the Salton Sea, California. Dewberry classified LiDAR for a project boundary that touches 623...

  3. Extended Reconstructed Sea Surface Temperature (ERSST)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis derived from the International Comprehensive...

  4. Erective Sea Embankment with PCC Piles

    Institute of Scientific and Technical Information of China (English)

    LIU Han-long; FEI Kang; DENG An; ZHANG Ting

    2005-01-01

    The sea embankment is a critical civil works in marine and coastal engineering. In this study, an innovative technique is proposed for constructing erective sea embankments. In the construction of sea embankments, this technique integrates PCC pile installation, PVDs drainage systems, and geotextile reinforcements, resulting in sea embankments with PCC piles. In the application of a sea embankment with PCC piles, PCC piles are employed as the retaining structures;the soft sea ground inside PCC piles is drained and improved by PVDs and vacuum-surcharge combined preloading; geotextile-reinforced backfills lying over the improved soft ground form the embankment body. Brief descrptions of the fundamentals, design and construction of the sea embankment with PCC piles are presented. A case study on the stability of sea embankment with PCC piles is presented as well.

  5. Range Extent for southern sea otters 2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS shapefile "Range extent of southern sea otters 2016" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris...

  6. Biogeochemistry of iron in the Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Moffett, J.W.; Vedamati, J.; Goepfert, T.J.; Pratihary, A.K.; Gauns, M.; Naqvi, S.W.A.

    The Arabian Sea is a productive basin where seasonal upwelling and convective mixing result in high surface nutrient concentrations and widespread algal blooms. The factors controlling primary productivity in the Arabian Sea are of interest because...

  7. Quarterly Fishery Surveys - Salton Sea [ds428

    Data.gov (United States)

    California Department of Resources — In the spring of 2003, California Department of Fish and Game (CDFG) personnel began quarterly sampling of Salton Sea fish at fourteen stations around the sea, as...

  8. Implementing the European SEA Directive in planning

    DEFF Research Database (Denmark)

    Kørnøv, Lone

    The paper describes how the European SEA Directive can complement the existing planning practice in Denmark.......The paper describes how the European SEA Directive can complement the existing planning practice in Denmark....

  9. Sea turtles sightings in North Carolina

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea turtles sightings are reported to the NMFS Beaufort Laboratory sea turtle program by the general public as they are fishing, boating, etc. These sightings...

  10. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Science.gov (United States)

    2010-10-01

    ... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) ATLANTIC COASTAL FISHERIES COOPERATIVE... must: (1) Notify the sea sampler/observer of any sea turtles, marine mammals, or other specimens taken by the vessel. (2) Provide the sea sampler/observer with sea turtles, marine mammals, or...

  11. Estimating sea floor dynamics in the Southern North Sea to improve bathymetric survey planning

    NARCIS (Netherlands)

    Dorst, Leendert Louis

    2009-01-01

    Safe nautical charts require a carefully designed bathymetric survey policy, especially in shallow sandy seas that potentially have dynamic sea floor patterns. Bathymetric resurveying at sea is a costly process with limited resources, though. A pattern on the sea floor known as tidal sand waves is c

  12. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2014-09-30

    1 Multiscale Models of Melting Arctic Sea Ice Kenneth M. Golden University of Utah, Department of Mathematics phone: (801) 581-6851...feedback has played a major role in the recent declines of the summer Arctic sea ice pack. However, understanding the evolution of melt ponds and sea...Models of Melting Arctic Sea Ice 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER

  13. [Multiple scattering of visible and infrared light by sea fog over wind driving rough sea surface].

    Science.gov (United States)

    Sun, Xian-Ming; Wang, Hai-Hua; Lei, Cheng-Xin; Shen, Jin

    2013-08-01

    The present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transfer theory. The reflection function of a statistically rough ocean surface was obtained using the standard Kirchhoff formulation, with shadowing effects taken into account. The reflection properties of the combined sea fog and ocean surface were obtained employing the adding method, and the results indicated that the reflected light intensity of sea fog increased with the sea background.

  14. Increased CO2 uptake due to sea ice growth and decay in the Nordic Seas

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Bendtsen, Jørgen; Petersen, L.T.

    2009-01-01

    uptake in the Nordic Seas is currently unknown. We present evidence from 50 localities in the Arctic Ocean that dissolved inorganic carbon is rejected together with brine from growing sea ice and that sea ice melting during summer is rich in carbonates. Model calculations show that melting of sea ice......The uptake rates of atmospheric CO2 in the Nordic Seas are among the highest in the world's oceans. This has been ascribed mainly to a strong biological drawdown, but chemical processes within the sea ice itself have also been suggested to play a role. The importance of sea ice for the carbon...

  15. India and the South China Sea Dispute

    Institute of Scientific and Technical Information of China (English)

    Ma Jiali

    2012-01-01

    South China Sea is a sea area of great significance. It lies between the Pacific and Indian Oceans, a crucial waterway bridging East Asia, Southeast Asia and South Asia. In general, South China Sea is a rich deposit of oil and fishing resources, a transportation hub of strategic importance, and an important buffer zone to safeguard China's maritime rights and interests.

  16. Messinian events in the Black Sea

    NARCIS (Netherlands)

    van Baak, Christiaan G C; Radionova, Eleanora P.; Golovina, Larisa A.; Raffi, Isabella; Kuiper, Klaudia F.; Vasiliev, Iuliana; Krijgsman, Wout

    2015-01-01

    Past hydrological interactions between the Mediterranean Sea and Black Sea are poorly resolved due to complications in establishing a high-resolution time frame for the Black Sea. We present a new greigite-based magnetostratigraphic age model for the Mio-Pliocene deposits of DSDP Hole 380/380A,

  17. 33 CFR 2.22 - Territorial sea.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Territorial sea. 2.22 Section 2... Jurisdictional Terms § 2.22 Territorial sea. (a) With respect to the United States, the following apply— (1) Territorial sea means the waters, 12 nautical miles wide, adjacent to the coast of the United States...

  18. Biogeographic classification of the Caspian Sea

    DEFF Research Database (Denmark)

    Fendereski, F.; Vogt, M.; Payne, Mark

    2014-01-01

    using the Hierarchical Agglomerative Clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total...... confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics....

  19. 50 CFR 223.205 - Sea turtles.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Sea turtles. 223.205 Section 223.205... Threatened Marine and Anadromous Species § 223.205 Sea turtles. (a) The prohibitions of section 9 of the Act (16 U.S.C. 1538) relating to endangered species apply to threatened species of sea turtle, except...

  20. Parasites in the Wadden Sea food web

    NARCIS (Netherlands)

    Thieltges, D.W.; Engelsma, M.Y.; Wendling, C.C.; Wegner, M.

    2013-01-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest