WorldWideScience

Sample records for aegean sea

  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...

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

    OpenAIRE

    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). O...

  3. Cephalopods distribution in the southern Aegean Sea

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. Wind Atlas of Aegean Sea with SAR data

    DEFF Research Database (Denmark)

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

    2013-01-01

    The Global Wind Atlas project is established to create a “free-to-use” wind atlas of the whole globe. The modelling chain of the project includes micro-scale models and new reanalysis datasets. Local measurements are planed to be use for test and validation. Unfortunately, it is not always possible...... satellite radar technologies made it possible to use Synthetic Aperture Radars (SAR) for wind speed and direction measurements at offshore locations. In this study, a new technique of making wind atlases is applied to the region of Aegean Sea is presented. The method has been tested and validated in the...... to find long term offshore measurement to make wind statistics. The main reason is the cost of setup and maintenance of an offshore mast. One of the regions which has high potential in wind resources but so far is without any long term offshore measurement is the Aegean sea. Recent developments in...

  6. Modeling of the upwelling hydrodynamics in the Aegean Sea

    Directory of Open Access Journals (Sweden)

    Y.G. SAVVIDIS

    2012-12-01

    Full Text Available The special features of the hydrodynamic circulation in the Aegean Sea referring to the development of regional upwelling coastal zones are studied by means of a mathematical model. The modeling effort is focused on the tracing of coastal areas, where upwelling events are frequently observed during the summer meteorological conditions. These areas are characterized by the enrichment of surface waters with nutrients and, consequently, increased fish production. The phenomenon is studied by the use of a two-layer mathematical model comprising the surface heated zone and the rest of the water column. The numerical solution of the model is based on the finite differences method. The wind shear applied over the stratified basin, with predefined density stratification and initial water-layers thickness, and the gravity and Coriolis forces taken into account, constitute the basic external factors for the generation of the hydrodynamic circulation in the area of the Aegean Sea. The calibration and the validation of the model are performed by the comparison of the model output to the data and observations reported in valid scientific sources. The aim of the paper is to demonstrate the significant contribution of numerical models to the better understanding of the hydrodynamics governing the Aegean water circulation as well as the tracing of upwelling zones.

  7. The Aegean Sea marine security decision support system

    Directory of Open Access Journals (Sweden)

    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.

  8. Oil pollution in the surface water of the Aegean Sea

    OpenAIRE

    Öztürk, Bayram; Güven, Kasim C.; Nesimigil, Filiz; Cumali, Selin; Dede, Ayhan

    2006-01-01

    Abstract Oil pollution in the surface water of the Aegean Sea was investigated from the Çanakkale Strait (Dardanelles) to the Marmaris Harbour, during 17-25 April in 2005. The oil pollution of samples was determined by UVF, through various crude oils and also chrysene as references materials. The oil pollution in water was ranged from 6.17 μg/L at Datca to 59.58 μg/L at Kusadasi through Russian crude oil equivalent. The highest polluted areas were Babakale-Kusadasi Bay, West of Giadoros Islan...

  9. Severe accidents due to windsurfing in the Aegean Sea.

    Science.gov (United States)

    Kalogeromitros, A; Tsangaris, H; Bilalis, D; Karabinis, A

    2002-06-01

    Windsurfing is a popular sport and has recently become an Olympic event. As an open-air water activity that requires the participant to be in perfect physical condition, windsurfers may be prone to accidents when certain basic rules or procedures are violated. The current study monitored severe injuries due to windsurfing over a period of 12 months in the Aegean Sea in Greece. Our study revealed 22 cases of severe accidents due to windsurfing, with a wide range of injuries including head injuries, spinal cord injuries, and severe fractures of the extremities. Prolonged hospitalization, severe disability and two deaths occurred as consequences of these accidents. The study examined the characteristics of these patients and the possible risk factors and conditions associated with the accidents. We also focused on the most common types of injuries and reviewed the mechanisms that may provoke them. Water sports and particularly windsurfing represent a major challenge for the emergency medical system, especially in the Aegean Sea. Hundreds of islands, kilometres of isolated coasts, millions of tourists, an extended summer period and rapidly changing weather create conditions that constantly test the efficacy of the emergency services. The development of an appropriate infrastructure and maximum control of the risk factors causing these accidents could reduce the morbidity and mortality that, unfortunately but rather predictably, accompany this popular summer activity. PMID:12131638

  10. 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.

  11. Re-distribution of 137Cs Chernobyl signal in the Aegean Sea

    International Nuclear Information System (INIS)

    The present levels of 137Cs in the water column of the Aegean Sea are at all depths, significantly higher than in the pre-Chernobyl period. The concentrations in surface and intermediate water show a linear relationship to salinity, indicating that mixing of Black Sea Water with highly saline waters of Levantine origin is the main process controlling 137Cs levels. The present 137Cs concentrations in deep basins of the North and South Aegean (3.7 - 5.5 Bq m-3) are the highest in the deep waters of the Mediterranean Sea. In the North Aegean the transfer of 137Cs from the surface layers to the bottom took place through the dense water formation events in 1987 and 1993. The 137Cs levels in the deep South Aegean are higher than expected, possibly in relation to a contribution of N-Aegean deep waters. (author)

  12. Black Sea and Mediterranean Sea interaction: influence of the North Aegean dynamics

    Science.gov (United States)

    Androulidakis, Yannis; Krestenitis, Yannis; Kourafalou, Vassiliki

    2013-04-01

    The brackish Black Sea Waters outflow to the Aegean Sea, through the Dardanelles Straits, affects and determines significantly the hydrodynamic and physical characteristics of the Aegean Sea. At the same time, it affects several biological parameters, like chl-a concentrations, and, therefore, the general quality of the marine environment. The investigation and mathematical simulation of the North Aegean's physical oceanography contributes to the knowledge and understanding of the buoyant waters' circulation initial conditions in the wider East Mediterranean region. The implementation and adaptation of the 3-d hydrodynamic mathematical model HYCOM (Hybrid Coordinate Ocean Model) in the North Aegean Sea (1/50οx1/50o), significantly contributes to the investigation of the area's hydrodynamic circulation. HYCOM, due to its hybrid coordinate operation, can describe at a satisfactory level, all the different topography and mixing cases of the complicated N. Aegean region. In addition, the high resolution atmospheric forcing and the nesting with a data assimilated broader Mediterranean HYCOM model along the southern open boundary of the North Aegean model, benefit the quality of the results and constitutes an important tool on the description and understanding of the Black Sea influence to the region's dynamics. A fundamental objective is the application and comparison of different Dardanelles outflow parameterizations based a) on the Black Sea water budget, b) on current measurements from a telemetric station in Limnos Island, and c) on historical time series. The Black Sea Waters plume evolution and the circulation patterns are dependant on the outflow rate magnitude, the flow distribution inside the straits and the prevailing winds. The long-term simulation covers the period of the last 20 years (1990-2010), investigating several physical characteristics of the North Aegean Sea, such as the deep water masses evolution, the major Black Sea waters circulation patterns

  13. The influence of Black Sea Water inflow and its synoptic time-scale variability in the North Aegean Sea hydrodynamics

    Science.gov (United States)

    Mavropoulou, Apostolia-Maria; Mantziafou, Anneta; Jarosz, Ewa; Sofianos, Sarantis

    2016-02-01

    The exchange water fluxes between the Black Sea and the North Aegean Sea through the Dardanelles Strait constitute an essential factor for the general circulation of the region. The Black Sea Water (BSW) inflow to the Aegean plays an important role in the hydrography and circulation of the basin and can affect the North Aegean deep water formation processes. Numerical experiments evaluating the influence of the time-scale variability (synoptic and seasonal) and the seasonality (period of maximum/minimum) of the Black Sea Water inflow on the dynamics of the North Aegean basin were performed. The experiments were carried out for the period from August 2008 to October 2009, using observed upper and lower-layer fluxes from the Dardanelles Strait, high-resolution atmospheric forcing, and boundary conditions derived from an operational system (ALERMO). The large-scale spatial patterns of the circulation and the seasonal variability of the North Aegean circulation show that dynamics of the basin can effectively absorb most of the Black Sea Water inflow variability. The overall cyclonic circulation of the North Aegean Sea and the predominant cyclonic and anti-cyclonic features are robust and are little affected by the different lateral fluxes. However, differences in the seasonality of the BSW inflow have an important impact in the North Aegean water column structure, while the synoptic variability observed in the Black Sea Water inflow affects the kinetic energy of the basin and the pathway of the Black Sea Water plume.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Re-distribution of 137Cs Chernobyl signal in the Aegean Sea

    International Nuclear Information System (INIS)

    The Chernobyl accident produced a patchy deposition of radionuclides over the Eastern and Northern basins of the Mediterranean Sea, that was superimposed over the previous fallout from atmospheric nuclear weapon tests. The deposition of Chernobyl-derived 137Cs was particularly heavy onto the Black Sea (1.7 - 2.4 PBq) and the Aegean - Ionian Seas along the Greek coasts (800 TBq). Moreover, the inflow of surface Black Sea water through the Dardanelles Straits still constitutes a point source of the conservative 137Cs into the North Aegean Sea. The objective of this study is to discuss the relationship between the re-distribution of 137Cs Chernobyl signal in the Aegean Sea and water circulation in the area, with focus on the evolution in space and time on the events of deep water formation. Selected sampling was carried out in 1999, 2001, 2002 and 2003 by the Hellenic Centre for Marine Research and the Italian ENEA Marine Environment research Centre during oceanographic campaigns designed for other purposes. Due to the limited ship time available, particular attention was dedicated to gather information on the 137Cs vertical profiles in the water column of selected sites (deep North-Aegean Basins and Cretan Sea), where the signal of past events involving deep water formation is expected to be registered. The water exiting the Dardanelles undergoes mixing with North Aegean surface water. In the surface water, there is a clear trend of decreasing 137Cs concentration with increasing salinity, suggesting that mixing/dilution of Black Sea Water (BSW) with highly saline Aegean waters is the dominant process determining the 137Cs levels. Due to its low salinity, BSW acts as an insulation layer and, consequently, deep-water formation is rather infrequent in the North Aegean, taking place only at periods of reduced Black Sea outflow and/or exceptionally cold and dry winters. In the last 20 years there have been two major deep-water formation events in the North Aegean: in

  16. 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.

  17. 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.

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

    DEFF Research Database (Denmark)

    Badger, Merete; Hasager, Charlotte Bay; Hahmann, Andrea N.; Volker, Patrick; di Bella, Alessandro; Bingöl, Ferhat

    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...

  19. Vertical distribution of marine cyanobacteria Synechococcus spp. in the Black, Marmara, Aegean, and eastern Mediterranean seas

    Science.gov (United States)

    Uysal, Zahit

    2006-08-01

    The vertical distributions of the unicellular cyanobacteria Synechococcus were studied in several highly contrasting seas: the Black Sea, Sea of Marmara, Aegean Sea, and Mediterranean Sea. Cell abundances varied significantly on both vertical and horizontal scales in all physically and spatially discrete water masses. Epifluorescence microscope cell counts from all seas clearly showed that majority of the population remains suspended in the surface-mixed layer and decreases gradually towards the base of the euphotic zone. Surface spatial distributions in the Black Sea were heterogeneous. Salinity, rather than temperature, seemed to have the greatest impact on the surface distribution of cells in this highly eutrophic sea. Changes in abundance in the mixed layer were small compared to the abrupt changes below the halocline, especially in the Black Sea and the Sea of Marmara. In contrast to the Black Sea, the major population remains suspended above the depth of fluorescence maximum in the Aegean and eastern Mediterranean seas. Significant correlations ( r>P0.01) were observed between cell counts and physical and chemical parameters with depth in the Black Sea. In all seas, cells at subsurface chlorophyll- a maximum layer (SCML) reflected brighter and longer fluorescence than those present at the surface and below. Cell size derived from flow cytometry indicated the presence of larger cells at the surface mixed layer compared to those at depth.

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

    OpenAIRE

    Shiganova, T.A.; Christou, E. D.; Siokou, I.

    2012-01-01

    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 w...

  1. Structure and seismic stratigraphy of deep Tertiary basins in the northern Aegean Sea

    Science.gov (United States)

    Beniest, Anouk; Brun, Jean-Pierre; Smit, Jeroen; Deschamps, Rémy; Hamon, Youri; Crombez, Vincent; Gorini, Christian

    2015-04-01

    Whereas active basin formation in the Aegean Sea is illustrated by seafloor bathymetry, the sedimentary and tectonic history of Tertiary basins is poorly known as existing offshore industrial seismic and well-log data are not easily accessible. We studied the evolution of the northern Aegean Sea with a focus on the North Aegean Trough and the Northern Skyros Basin, which are amongst the deepest basins of the northern Aegean domain. Structural and seismic stratigraphic interpretation of a 2D seismic dataset retrieved in the 1970's is combined with the well-investigated records of the onshore deep basins of northern Greece and Western Turkey. A general seismic signature chart was established using onshore basin stratigraphy and poorly-constrained well data. The studied domain shows two sharp unconformities that correspond to the Eocene-Oligocene transition and the Miocene-Pliocene shift, respectively. These transitions were then used as pillars for a more detailed structural and seismic stratigraphic interpretation. A NW-SE trending seismic line that cross-cuts the southern part of the NE-SW-trending North Aegean Through displays the main features that are observed in the area: 1) an overall basin geometry that is rather symmetrical; 2) pre-Pliocene units affected by steep normal faults; 3) a rather constant thickness of Oligocene sediments that define a depocenter with an apparent NW-SE orientation; 4) an ablation of Miocene sediments by erosion, likely related to the Messinian Salinity Crises (MSC); (5) thick deltaic/turbiditic deposits in the NE-SW oriented central through of Neogene age; 6) trans-tensional growth patterns in Pliocene and Quaternary sediments that combine NE-SW steeply dipping fault zones, more likely corresponding to strike-slip corridors, and E-W-trending normal faults. The evidence listed above suggest that, in the northern Aegean Sea, (1) extension started at the latest during the Late Eocene/Early Oligocene (data quality does not allow for a

  2. 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. PMID:26902670

  3. Oil pollution in surface water of the Turkish side of the Aegean and Eastern Mediterranean Seas

    OpenAIRE

    Öztürk, Bayram; Altuğ, Gülşen; Çiftçi, Mine Çardak and Pelin S.

    2007-01-01

    Abstract Oil pollution of the South part of the Aegean Sea and Mediterranean Sea was investigated at 48 stations from the Bozburun Peninsula to İskenderun buy, during 17-28 August 2006.The highly carbon concentration of the samples was determined by UVF by using Iraq crude oil and also chrysene as references materials. The oil pollution in examined sea water was 4.16 µg/L in Antalya Bay and 100.33 µg/L in Iskenderun through Iraq crude oil equivalent. The highest polluted areas are Iskenderun,...

  4. Protozoan parasites in cultured mussels Mytilus galloprovincialis in the Thermaikos Gulf (north Aegean Sea, Greece).

    Science.gov (United States)

    Rayyan, Abdalnasser; Damianidis, Panagiotis; Antoniadou, Chryssanthi; Chintiroglou, Chariton C

    2006-06-23

    The protozoans Ancistrum mytili (Oligohymenophorea: Ancistridae) and Marteilia refringens/maurini (Marteiliidea: Marteiliidae) were found parasitizing cultured mussels Mytilus galloprovincialis L. in the Thermaikos Gulf (north Aegean Sea, Greece). The former did not affect the condition index of infected mussels, in contrast to the latter, which did so and which also induced hemocyte infiltration in the affected digestive epithelium. The prevalence of both parasites was relatively high in a polluted area. PMID:16903237

  5. Static Stress Changes Inverted from Microseismicity in Eastern Aegean Sea

    Science.gov (United States)

    Leptokaropoulos, Konstantinos; Papadimitriou, Eleftheria; Orlecka-Sikora, Beata; Karakostas, Vassilios

    2014-05-01

    In this study we attempted to derive static stress field variations from the changes of earthquake production rates in Kusadasi bay and Samos island (eastern Aegean), by applying the Dieterich et al. (2000) Rate/State formulation. The calculation of stress changes from earthquake occurrence rates fluctuations should be obtained from catalogues which achieve adequate spatial and temporal resolution and well determined hypocenter coordinates. For this reason we took advantage of the data from a regional network operating since July of 2007, providing continuous monitoring of microseismicity, along with data available from seismological stations of the permanent Hellenic Unified Seismological Network (HUSN). The high accuracy and large sized regional catalogue is utilized for inverting seismicity rate changes into stress variation through a Rate/State dependent friction model. After explicitly determining the physical parameters incorporating in the modeling (reference seismicity rates, characteristic relaxation time, constitutive properties of fault zones) we investigated stress changes in both space and time regime and their possible connection with earthquake clustering and fault interactions. The main interest is focused on the June 2009 Samos Mw=5.1 event, which was followed by an intense seismic activity for several days. We attempt to reproduce and interpret stress changes both before and after the initiation of this seismic burst. The differences between the earthquake occurrence rates before and after the main shock are used as input data in a stress inversion algorithm based upon the Rate/State dependent friction concept in order to provide an estimation of stress changes. Diverse assumptions and combinations of the parameters values are tested for the model performance and sensitivity to be evaluated. The approach followed here could provide evidence of the robustness of the seismicity rate changes usage as a stress meter for both positive and negative

  6. Focal mechanism determinations of earthquakes along the North Anatolian fault, beneath the Sea of Marmara and the Aegean Sea

    Science.gov (United States)

    Nakano, Masaru; Citak, Seckin; Kalafat, Doğan

    2015-09-01

    We determined the centroid moment tensor (CMT) solutions of earthquakes that occurred along the North Anatolian fault (NAF) beneath the Sea of Marmara and the Aegean Sea, using data obtained from Turkey's broad-band seismograph network. The CMT solution of the 2014 Aegean Sea earthquake ( Mw 6.9) represents a strike-slip fault, consistent with the geometry of the 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. 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.

  7. Diet composition of the round sardinella Sardinella aurita Valenciennes, 1847 (Osteichthyes: Clupeidae) in the Turkish Aegean Sea

    OpenAIRE

    Bahar Bayhan

    2015-01-01

    Sardinella aurita, a round sardinella from Clupeidae family, is a pelagic fish found in tropical and temperate seas, just like other members of its family. The species has a wide distribution and its contribution to Mediterranean and international fisheries production potential is high. In Turkey, this species has a wide distribution in the Mediterranean Sea and the Aegean Sea, on the other hand, it is rarely seen in the Black Sea and Marmara Sea. Apart from its economic contribution to the w...

  8. 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.

  9. Distribution of the Demersal Fishes on the Continental Shelves of the Levantine and North Aegean Seas (Eastern Mediterranean)

    OpenAIRE

    Keskin, Çetin; Turan, Cemal; Ergüden, Deniz

    2011-01-01

    The aim of this study was to investigate the distribution patterns of demersal fishes on the continental shelves of the north-eastern Levantine and north-eastern Aegean seas. Fish samples were collected by bottom trawl. A total of 29 hauls were carried out, 15 hauls between 43 to 121 m depth in the north-eastern Levantine Sea and 14 hauls between 65 to 100 m depth in the north-eastern Aegean Sea. The total trawled area for both region was 1.87 km2. Cluster analysis and non-metric multidimens...

  10. A new contribution to the Late Quaternary tephrostratigraphy of the Mediterranean: Aegean Sea core LC21

    Science.gov (United States)

    Satow, C.; Tomlinson, E. L.; Grant, K. M.; Albert, P. G.; Smith, V. C.; Manning, C. J.; Ottolini, L.; Wulf, S.; Rohling, E. J.; Lowe, J. J.; Blockley, S. P. E.; Menzies, M. A.

    2015-06-01

    Tephra layers preserved in marine sediments can contribute to the reconstruction of volcanic histories and potentially act as stratigraphic isochrons to link together environmental records. Recent developments in the detection of volcanic ash (tephra) at levels where none is macroscopically visible (so-called 'crypto-tephra') have greatly enhanced the potential of tephrostratigraphy for synchronising environmental and archaeological records by expanding the areas over which tephras are found. In this paper, crypto-tephra extraction techniques allow the recovery of 8 non-visible tephra layers to add to the 9 visible layers in a marine sediment core (LC21) from the SE Aegean Sea to form the longest, single core record of volcanic activity in the Aegean Sea. Using a novel, shard-specific methodology, sources of the tephra shards are identified on the basis of their major and trace element single-shard geochemistry, by comparison with geochemical data from proximal Mediterranean volcanic stratigraphies. The results indicate that the tephra layers are derived from 14 or 15 separate eruptions in the last ca 161 ka BP: 9 from Santorini; 2 or 3 from Kos, Yali, or Nisyros; 2 from the Campanian province; and one from Pantelleria. The attributions of these tephra layers indicate that 1) inter-Plinian eruptions from Santorini may have produced regionally significant tephra deposits, 2) marine tephrostratigraphies can provide unique and invaluable data to eruptive histories for island volcanoes, and 3) tephra from both Pantelleria and Campania may be used to correlate marine records from the Aegean Sea to those from the Tyrrhenian, Adriatic and Ionian Seas.

  11. Hemiasterella aristoteliana n. sp. (Porifera, Hadromerida) from the Aegean Sea with a discussion on the family Hemiasterellidae

    OpenAIRE

    Voultsiadou-Koukoura, Eleni; Van, Soest

    1991-01-01

    A representative of the genus Hemiasterella Carter, 1879 was found for the first time in the Mediterranean Sea during sampling in the shallow waters of the northern Aegean Sea. The new species, H. aristoteliana, is compared with Atlantic Hemiasterella elongata Topsent, 1928. The status of the family Hemiasterellidae is discussed.

  12. Physical and chemical processes of air masses in the Aegean Sea during Etesians: Aegean-GAME airborne campaign

    Czech Academy of Sciences Publication Activity Database

    Tombrou, M.; Bossioli, E.; Kalogiros, J.; Allan, J. D.; Bacak, A.; Biskos, J.G.; Coe, H.; Dandou, A.; Kouvarakis, G.; Mihalopoulos, N.; Percival, C. J.; Protonotariou, A. P.; Szabó-Takács, Beáta

    2015-01-01

    Roč. 506, feb (2015), s. 201-216. ISSN 0048-9697 Institutional support: RVO:67179843 Keywords : Aegean-GAME campaign * Airborne measurements * Marine Atmospheric Boundary Layer * Turbulent fluxes * Gas and aero sol composition * Etesian winds Subject RIV: EH - Ecology, Behaviour Impact factor: 4.099, year: 2014

  13. Reconstructing Holocene sea surface salinity changes in the Northern Aegean Sea: evidence from morphological variations of Emiliania huxleyi-coccoliths

    Science.gov (United States)

    Herrle, Jens O.; Gebühr, Christina; Bollmann, Jörg; Giesenberg, Annika; Kranzdorf, Philip

    2013-04-01

    The Aegean Sea is a key area for our understanding of the impact of changes in the hydrological cycle on ocean circulation in the Mediterranean Sea. The Aegean Sea appears to be very sensitive to climate changes in Europe because of its small volume and the position between high- and low-latitude climate regimes. Therefore, it is assumed to record environmental change, especially changes in sea surface water salinity (SSS) without a significant time lag with respect to the forcing process (Rohling et al., 2002). However, up to date, SSS cannot be easily reconstructed from geological archives because several assumptions need to be made that lead to a significant error of the salinity estimates (e.g. Rohling, 2000). Here, we present the first high resolution SSS reconstruction from a Holocene sediment core based on a recently developed transfer function using the morphological variation of Emiliania huxleyi coccoliths (Bollmann & Herrle 2007, Bollmann et al., 2009). The core is located in the northern Aegean Sea (eastern Mediterranean Basin) and covers the time period 3 -11ka ago. Sea surface water salinity in the Aegean Sea has varied in concert with temperature oscillations as recorded in Greenland ice cores (iGISP2 ice core δ18O record) with a periodicity of about 900 years (Schulz & Paull, 2002). Four major SSS events can be identified at about 3.9, 4.7, 6.4, 7.4, and 8.2 ka in the northern Aegean Sea that correlate with increases in GISP2 δ18O (Schulz & Paull, 2002) as well as decreasing percentages of tree pollen studied at the same core expect for 3.9 ka (Kotthoff et al., 2008). The most prominent salinity increase occurred during the short-lived 8.2 kyr cold event (e.g., Rohling & Pälike, 2005), which was most likely triggered by a melt-water related perturbation of the Atlantic Meridional Overturning and associated decrease of ocean heat transport to the North Atlantic. We suggest that the salinity fluctuations in the northern Aegean Sea are related to

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

    OpenAIRE

    Banu Kutlu

    2014-01-01

    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 signifi...

  15. Distribution and transfer of dissolved trace metals in the North Aegean Sea

    International Nuclear Information System (INIS)

    Sampling for trace metal analysis in the North Aegean Sea took place from 13-25 May 1997 with the R/V Aegaeo. Samples were collected from 12 Go-flo bottles attached to the rosette-CTD system and were filtered through 0.45 μm membrane filters, on-board, under a nitrogen atmosphere. Precautions were taken during handling of samples to minimise contamination. The samples were acidified and carried back to the clean laboratory for further analysis. A preconcentration step using the chelex-100 resin followed. Trace metals were determined on a Perkin-Elmer AAS equipped with a HGA-700

  16. Preliminary biological data on Pomadasys incisus (Osteichthyes: Haemulidae in the Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    K. KAPIRIS

    2012-12-01

    Full Text Available The present paper gives, for the first time, some biological data concerning Pomadasys incisus in theArgolikos Gulf (C. Aegean Sea. The bastard grunt (Pomadasys incisus is a thermophilic species welladapted in the above area, but the status of fishery suggests an overexploitation. The sex ratio was infavour of males. The length frequency distribution did not differ between the sexes. Growth in weight wasestimated by means of the length-weight relationship. Reproduction seemed to take place in summer. Certainmorphometric characters appeared to be useful while comparing populations among the differentpopulations in the Mediterranean.

  17. 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. PMID:25434031

  18. Habitat Selection and Temporal Abundance Fluctuations of Demersal Cartilaginous Species in the Aegean Sea (Eastern Mediterranean)

    Science.gov (United States)

    Maravelias, Christos D.; Tserpes, George; Pantazi, Maria; Peristeraki, Panagiota

    2012-01-01

    Predicting the occurrence of keystone top predators in a multispecies marine environment, such as the Mediterranean Sea, can be of considerable value to the long-term sustainable development of the fishing industry and to the protection of biodiversity. We analysed fisheries independent scientific bottom trawl survey data of two of the most abundant cartilaginous fish species (Scyliorhinus canicula, Raja clavata) in the Aegean Sea covering an 11-year sampling period. The current findings revealed a declining trend in R. clavata and S. canicula abundance from the late ′90 s until 2004. Habitats with the higher probability of finding cartilaginous fish present were those located in intermediate waters (depth: 200–400 m). The present results also indicated a preferential species' clustering in specific geographic and bathymetric regions of the Aegean Sea. Depth appeared to be one of the key determining factors for the selection of habitats for all species examined. With cartilaginous fish species being among the more biologically sensitive fish species taken in European marine fisheries, our findings, which are based on a standardized scientific survey, can contribute to the rational exploitation and management of their stocks by providing important information on temporal abundance trends and habitat preferences. PMID:22536389

  19. 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.

  20. 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.

  1. Po 210 in the Turkish coast of the Aegean sea ecosystem

    International Nuclear Information System (INIS)

    Full text: Po 210 is a natural radionuclide which constitutes the major source of natural radiation received by humans through the consumption of food and contributes more to the total radiation dose than environmental levels of anthropogenic radionuclides, such as Cs 137 and Pu 239, 240. For Turkish Coast of Aegean Sea Ecosystem, although there some investigations presently available on some natural radionuclides and gross radioactivity concentrations, data on Po 210 in the sea water, bottom sediment and marine biota are very scarce. The aim of the present study is to improve our knowledge about the levels of radioactive polonium along Aegean Turkish Coastal zone and also assess its enhancement from the fosil fuel industry like coal-fired power plants (CPPs), oil industry and from phosphate industry, all located along the coast and also from the discharge of a number streams and rivers in the region. This paper introduces an extensive set of data and related results on Po 210 in surface sea water, bottom sediments, fishes and mussels (Mytilus galloprovincialis) obtained from 6 stations (Canakkale, Dikili, Foca, Ceshme, Didim and Bodrum) along the coast in the period of 2004-2005. In the bottom sediments, Po 210 concentration varies between 21±1 and 214±24 Bq kg-1 dry wt with an average value of 70±7 Bq kg-1. The concentrations in surface water of the sea during the sampling period are around 0.016±0.001 Bq l-1. Amongst the fishes, small pelagic plankton feding fish like anchovy (Engraulis encrasicolus) and sardine (Sardine plichardus) tend to accumulate more Po 210. The concentration of Po 210 in mussels (Mytilus galloprovincialis) varies between 55±5 and 2288±124 Bq kg-1 which is in general higher than those given in literature for other countries. The highest Po 210 concentration belongs to Didim mussels for winter time with a shell length of 4-6 cm

  2. Holocene Climatic Optimum centennial-scale paleoceanography in the NE Aegean (Mediterranean Sea)

    Science.gov (United States)

    Triantaphyllou, Maria V.; Gogou, Alexandra; Dimiza, Margarita D.; Kostopoulou, Sofia; Parinos, Constantine; Roussakis, Grigoris; Geraga, Maria; Bouloubassi, Ioanna; Fleitmann, Dominik; Zervakis, Vassilis; Velaoras, Dimitris; Diamantopoulou, Antonia; Sampatakaki, Angeliki; Lykousis, Vassilis

    2016-02-01

    Combined micropaleontological and geochemical analyses of the high-sedimentation gravity core M-4G provided new centennial-scale paleoceanographic data for sapropel S1 deposition in the NE Aegean Sea during the Holocene Climatic Optimum. Sapropel layer S1a (10.2-8.0 ka) was deposited in dysoxic to oxic bottom waters characterized by a high abundance of benthic foraminiferal species tolerating surface sediment and/or pore water oxygen depletion (e.g., Chilostomella mediterranensis, Globobulimina affinis), and the presence of Uvigerina mediterranea, which thrives in oxic mesotrophic-eutrophic environments. Preservation of organic matter (OM) is inferred based on high organic carbon as well as loliolide and isololiolide contents, while the biomarker record and the abundances of eutrophic planktonic foraminifera document enhanced productivity. High inputs of terrigenous OM are attributed to north Aegean borderland riverine inputs. Both alkenone-based sea surface temperatures (SSTs) and δO18 G. bulloides records indicate cooling at 8.2 ka (S1a) and ~7.8 ka (S1 interruption). Sapropelic layer S1b (7.7-6.4 ka) is characterized by rather oxic conditions; abundances of foraminiferal species tolerant to oxygen depletion are very low compared with the U. mediterranea rise. Strongly fluctuating SSTs demonstrate repeated cooling and associated dense water formation, with a major event at 7.4 ka followed by cold spells at 7.0, 6.8, and 6.5 ka. The prominent rise of the carbon preference index within the S1b layer indicates the delivery of less degraded terrestrial OM. The increase of algal biomarkers, labile OM-feeding foraminifera and eutrophic planktonic species pinpoints an enhanced in situ marine productivity, promoted by more efficient vertical convection due to repeated cold events. The associated contributions of labile marine OM along with fresher terrestrial OM inputs after ~7.7 ka imply sources alternative/additional to the north Aegean riverine borderland sources for

  3. Accumulation rates and sediment deposition in the Goekova Bay in Aegean Sea Turkish Coast

    International Nuclear Information System (INIS)

    Sediment accumulation rates were estimated from the vertical distribution of excess 210Pb in sediment cores collected at six stations in the Goekova Bay near the heavily industrialized Turkish Coastal zone of the Aegean Sea. Total 210Pb was determined by measuring 210Po activities. The sediment accumulation rates were calculated to vary from 0.32±0.01 cm yr-1 (0.17±0.01 g cm-2 yr-1) to 1.92±0.20 cm yr-1 (1.13±0.10 g cm-2 yr-1). The unsupported 210Pb flux was calculated from the accumulated dry matter of the examined slices and their unsupported 210Pb concentrations. The flux of unsupported 210Pb varies between 62±5 and 105±8 Bq m-2 yr-1. The average depositional flux was found to be considerably higher for cores from the Mediterranean

  4. STS-56 ESC Earth observation of Limnos Island in the Aegean Sea

    Science.gov (United States)

    1993-01-01

    STS-56 electronic still camera (ESC) Earth observation image taken aboard Discovery, Orbiter Vehicle (OV) 103, shows Limnos Island in the Aegean Sea. The image was recorded with a 300mm lens on the Hand-held, Earth-oriented, Real-time, Cooperative, User-friendly, Location-targeting and Environmental System (HERCULES). HERCULES is a device that makes it simple for Shuttle crewmembers to take pictures of Earth as they merely point a modified 35mm camera and shoot any interesting feature, whose latitude and longitude are automatically determined in real time. In this observation, the center coordinates are 39.9 degrees north latitude and 25.3 degrees east longitude. The camera was in shutter priority mode with a 1/500-second shutter speed and -2/3 exposure compensation. Digital file name is ESC03037.IMG.

  5. 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.

  6. 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.

  7. Chemical composition and hygroscopic properties of aerosol particles over the Aegean Sea

    Directory of Open Access Journals (Sweden)

    S. Bezantakos

    2013-03-01

    Full Text Available The chemical composition and water uptake characteristics of sub-micrometer atmospheric particles in the region of the Aegean Sea were measured between 25 August and 11 September 2011 in the framework of the Aegean-Game campaign. High time-resolution measurements of the chemical composition of the particles were conducted using an airborne compact Time-Of-Flight Aerosol Mass Spectrometer (cTOF-AMS. These measurements involved two flights from the island of Crete to the island of Lemnos and back. A Hygroscopic Tandem Differential Mobility Analyzer (HTDMA located on the island of Lemnos was used to measure the ability of the particles to take up water. The HTDMA measurements showed that the particles were internally mixed, having hygroscopic growth factors that ranged from 1.00 to 1.59 when exposed to 85% relative humidity. When the aircraft flew near the ground station on Lemnos, the cTOF-AMS measurements showed that the organic volume fraction of the particles ranged from 43 to 56%. These measurements corroborate the range of hygroscopic growth factors measured by the HTDMA during that time. Good closure between HTDMA and cTOF-AMS measurements was achieved when assuming that the organic species were hydrophobic and had an average density that corresponds to aged organic species. Using the results from the closure study, the cTOF-AMS measurements were employed to determine a representative aerosol hygroscopic parameter κmix for the whole path of the two flights. Calculated κmix values ranged from 0.17 to 1.03 during the first flight and from 0.15 to 0.93 during the second flight. Air masses of different origin as determined by back trajectory calculations can explain the spatial variation in the chemical composition and κmix values of the particles observed in the region.

  8. 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.

  9. 137Cs vertical distribution at the deep basins of the North and Central Aegean Sea, Greece

    International Nuclear Information System (INIS)

    Large volume seawater samples were collected for the determination of 137Cs concentration along with depth in the deep basins of North and Central Aegean Sea. The vertical 137Cs distribution showed maximum concentration at the bottom of the basins, while the minimum values corresponded to the intermediate layer, where Levantine water exists. The surface 137Cs activity is found to lie between the two limits and is originated from the Black Sea waters. The typical oceanographic advection–diffusion balance model is modified to a diffusion-settling-decay balance model to better understand the vertical distribution and variation of the 137Cs concentration in the deep basins. In addition, the diffusivity of each basin, as well as the settling speed of particulate 137Cs is also estimated. The results are compared with theoretical approach as well as with previous data. - Highlights: • Three deep basins were studied using 137Cs as a tracer. • Deep waters constitute 137Cs repositories due to deep water formation followed Chernobyl accident. • Diffusivities, as well as particulate 137Cs settling speeds are estimated

  10. 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.

  11. 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.

  12. Review of variations in Mw Mw = 6.5 aegean sea earthquake sample

    Directory of Open Access Journals (Sweden)

    O. Yildirim

    2015-10-01

    Full Text Available Turkey is a country located in Middle Latitude zone and in which tectonic activity is intensive. Lastly, an earthquake of magnitude 6.5Mw occurred at Aegean Sea offshore on date 24 May 2014 at 12:25 UTC and it lasted approximately 40 s. The said earthquake was felt also in Greece, Romania and Bulgaria in addition to Turkey. In recent years seismic origin ionospheric anomaly detection studies have been done with TEC (Total Electron Contents generated from GNSS (Global Navigation Satellite System signals and the findings obtained have been revealed. In this study, TEC and positional variations have been examined seperately regarding the earthquake which occurred in the Aegean Sea. Then The correlation of the said ionospheric variation with the positional variation has been investigated. For this purpose, total fifteen stations have been used among which the data of four numbers of CORS-TR stations in the seismic zone (AYVL, CANA, IPSA, YENC and IGS and EUREF stations are used. The ionospheric and positional variations of AYVL, CANA, IPSA and YENC stations have been examined by Bernese 5.0v software. When the (PPP-TEC values produced as result of the analysis are examined, it has been understood that in the four stations located in Turkey, three days before the earthquake at 08:00 and 10:00 UTC, the TEC values were approximately 4 TECU above the upper limit TEC value. Still in the same stations, one day before the earthquake at 06:00, 08:00 and 10:00 UTC, it is being shown that the TEC values were approximately 5 TECU below the lower limit TEC value. On the other hand, the GIM-TEC values published by the CODE center have been examined. Still in all stations, it has been observed that three days before the earthquake the TEC values in the time portions of 08:00 and 10:00 UTC were approximately 2 TECU above, one day before the earthquake at 06:00, 08:00 and 10:00 UTC, the TEC values were approximately 4 TECU below the lower limit TEC value. Again, by

  13. Spectroscopic studies of humic acids from subsurface sediment samples collected across the Aegean Sea

    Directory of Open Access Journals (Sweden)

    F. SAKELLARIADOU

    2012-12-01

    Full Text Available Natural humic acids are biogenic, structurally complex and heterogeneous, refractory, acidic, yellow-to black-coloured organic polyelectrolytes of relatively high molecular weight. They occur in all soils, sediments, fresh waters, and seawaters. Humic acids represent the largest portion of nonliving soil organic matter. In the present paper, humic substances were isolated from marine subsurface sediment samples collected across the Aegean sea (in Greece and especially from a marine area extending northwards of the Samothraki plateau towards the north-eastern part of the island of Crete. In a following step, humic preparations were studied using infrared and fluorescence spectroscopy (emission, excitation and synchronous-scan excitation spectra were obtained. The infrared spectra suggested functional chemical groups such as as OH-, C-H aliphatic, C=C, C=O/COO-, salts of carboxylic acids, and also, in some cases, silicate anions or C-O from alcohols, esters and ethers. Fluorescence emission, excitation and synchronous scan excitation provided some valuable information concerning a probable origin (marine and/or terrestrial for the isolated humics.

  14. Macrobenthic community structure over the continental margin of Crete (South Aegean Sea, NE Mediterranean)

    Science.gov (United States)

    Tselepides, Anastasios; Papadopoulou, Konstantia-N.; Podaras, Dimitris; Plaiti, Wanda; Koutsoubas, Drosos

    2000-08-01

    Macrobenthic faunal composition, abundance, biomass and diversity together with a suite of sedimentary environmental parameters were investigated on a seasonal basis in order to determine factors regulating faunal distribution over the oligotrophic continental margin of the island of Crete (South Aegean Sea, North Eastern Mediterranean). Macrofaunal species composition was similar to that of the western Mediterranean and the neighboring Atlantic having several common dominant species. Mean benthic biomass, abundance and diversity decreased with depth, with a major transition zone occurring at 540 m, beyond which values declined sharply. At comparable depths biomass and abundance values were considerably lower to those found in the Atlantic, high-lighting the extreme oligotrophy of the area. The continental margin of Crete was characterised by a high diversity upper continental shelf environment (dominated by surface deposit feeding polychaetes) and a very low diversity slope and deep-basin environment (dominated by carnivorous and filter feeding polychaetes). Classification and ordination analyses revealed the existence of four principle clusters divided by a faunal boundary between 200 and 540 m, as well as beyond 940 m depth. Significant correlations between macrofauna and sediment parameters led to the conclusion that besides depth, food availability (as manifested by the concentration of chloroplastic pigments) is the principle regulating factor in the system. Such being the case, the prevailing hydrographic features that structure the pelagic food web and are directly responsible for the propagation of organic matter to the benthos also affect its community structure.

  15. 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.

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

    Science.gov (United States)

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

    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.

  17. 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

  18. 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.

  19. Temporal and spatial variations in provenance of Eastern Mediterranean Sea sediments: Implications for Aegean and Aeolian arc volcanism

    Science.gov (United States)

    Klaver, Martijn; Djuly, Thomas; de Graaf, Stefan; Sakes, Alex; Wijbrans, Jan; Davies, Gareth; Vroon, Pieter

    2015-03-01

    The Eastern Mediterranean Sea (EMS) is the last remnant of the Tethys Ocean that has been subducted to the north since the Jurassic. Subduction has led to the formation of multiple island arcs in the EMS region where the Aeolian and Aegean arcs are currently active. The EMS is surrounded by continents and receives a large sediment input, part of which is transported down with the subducting slab into the mantle and potentially contributes a major flux to the arc volcanism. An along-arc gradient in the composition of subducting sediment has been evoked to explain the distinct geochemical signature of the easternmost volcanic centre of the Aegean arc, but direct evidence for this proposal is lacking. We present a detailed study of the mineralogical, major-, trace elements and Sr-Nd-Hf-Pb isotope composition of 45 Neogene EMS sediment samples obtained from Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) drill sites and box cores to characterise their geochemical composition, distinguish provenance components and investigate the temporal and spatial variation in provenance to evaluate the potential changing contribution of subducted EMS sediment to Aegean and Aeolian arc volcanism. Based on trace element characteristics of EMS sediments, we can distinguish four provenance components. Nile sediment and Sahara dust are the main components, but contributions from the Tethyan ophiolite belt and arc volcanic rocks in the north are also recognised. Pliocene and Quaternary EMS sediment records a strong geochemical gradient where Nile River sediment entering the EMS in the east is progressively diluted by Sahara Desert dust towards the west. Pre-Messinian samples, however, have a remarkably homogeneous composition with Nile sediment characteristics. We relate this rapid increase in Sahara dust contribution to a late Miocene climate shift leading to decreased Nile runoff and aridification of the Sahara region. EMS sediment has a restricted range in Pb isotopes

  20. 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,...

  1. A list of macrofauna on the continental shelf of Gökçeada Island (northern Aegean Sea) with a new record (Gryphus vitreus Born, 1778) (Brachiopoda, Rhynchonellata) for the Turkish seas

    OpenAIRE

    Gönülal, Onur; Güreşen, Sedat Ozan

    2014-01-01

    Abstract Long-term sampling (1974-2013) of macro fauna of the Gökçeada Island (northern Aegean Sea) provided qualitative information on many taxa including Porifera, Cnidaria Mollusca, Arthropoda, Brachiopoda, Bryozoa, Spinculida, Echinodermata, Chordata. Gryphus vitreus (Brachiopoda) and Funiculina quadrangularis (Pallas, 1766) are the first records for the Turkish seas and the Aegean coast of Turkey, respectively. The present paper aims to describe macrofauna occurring on the continental sh...

  2. Modelling the water mass circulation in the Aegean Sea. Part I: wind stresses, thermal and haline fluxes

    Directory of Open Access Journals (Sweden)

    I. A. Valioulis

    Full Text Available The aim of this work is to develop a computer model capable of simulating the water mass circulation in the Aegean Sea. There is historical, phenomenological and recent experimental evidence of important hydrographical features whose causes have been variably identified as the highly complex bathymetry, the extreme seasonal variations in temperature, the considerable fresh water fluxes, and the large gradients in salinity or temperature across neighbouring water masses (Black Sea and Eastern Mediterranean. In the approach taken here, physical processes are introduced into the model one by one. This method reveals the parameters responsible for permanent and seasonal features of the Aegean Sea circulation. In the first part of the work reported herein, wind-induced circulation appears to be seasonally invariant. This yearly pattern is overcome by the inclusion of baroclinicity in the model in the form of surface thermohaline fluxes. The model shows an intricate pattern of sub-basin gyres and locally strong currents, permanent or seasonal, in accord with the experimental evidence.

  3. Diet composition of the round sardinella Sardinella aurita Valenciennes, 1847 (Osteichthyes: Clupeidae in the Turkish Aegean Sea

    Directory of Open Access Journals (Sweden)

    Bahar Bayhan

    2015-12-01

    Full Text Available Sardinella aurita, a round sardinella from Clupeidae family, is a pelagic fish found in tropical and temperate seas, just like other members of its family. The species has a wide distribution and its contribution to Mediterranean and international fisheries production potential is high. In Turkey, this species has a wide distribution in the Mediterranean Sea and the Aegean Sea, on the other hand, it is rarely seen in the Black Sea and Marmara Sea. Apart from its economic contribution to the world fisheries industry, the species has an important role in the food chain in regions it is found as it takes part in diet composition of its predators such as greater amberjack, and common dolphinfish. Nowadays, trophic levels are used in order to develop ecosystem based fisheries management strategies. For this purpose, diet composition of the round sardinella was investigated. Samples were obtained from commercial fishermen, who generally use purse seine and gill nets in Izmir Bay concerned during October 2010 - September 2011. A total of 434 S. aurita were collected all year round, with total lengths ranging 12.1 to 27.1 cm. Fish were dissected immediately after capture, stomachs removed and stored in formalin (10% until the contents were analysed. Stomach contents examined using a SZX7 Olympus stereo microscope. Prey items were identified to the lowest possible taxon. Forty eight species were identified, belonging to six major groups: Polychaeta, Crustacea, Mollusca, Chaetognatha, Tunicate and Teleostei. Finally crustaceans were the most important food item in terms of index of relative importance. At least 31 copepod species were identified, where Calanoida, Oithona nana, Oncaea media and Oithona plumifera appeared all year round with %IRI ≥ 10. With this study, the feeding regime of round sardinella, was identified in detail for the Aegean Sea of Turkey for the first time.

  4. 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...

  5. 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 -...

  6. A survey of metal pollution in mussels Mytilus galloprovincialis (L.1758) from northern coast of Turkish Aegean Sea

    International Nuclear Information System (INIS)

    Marine organisms generally, mussels and benthic fish are selected as suitable indicator species of coastal pollution, as they give complementary information on chemicals bioavailable in the water column and sediments, respectively. Bioaccumulation patterns of the different pollutants vary substantially among species. Habitat, season and food web play a key role on the bioaccumulation process. Filter feeder organisms accumulate most of the pollutants at more higher levels than those found in water column so that they permit to reflect the quality of coastal environments. Mediterranean mussels Mytilus galloprovincialis (L.1758) have criteria of ideal bio-monitors as sedentary and easy to sample over Mediterranean coastal zones. The aim of this study was to investigate the present status of the distribution of heavy metal levels in economically important bivalve from Northern coast of Turkish Aegean Sea. The mussels were collected by hand on rocks along the coastal zones at 5 sampling locations during the period of November 2002-April 2003. The 5 sampling stations are shown. All samples transported daily to the laboratory. Edible soft tissues of mussels were removed from the shells on the day of sampling and were kept at frozen at -30 deg. C until the analysis. The collected mussels were divided in two groups according to their size (small size 3-4 cm. and big size 7-8 cm.).The composite samples of soft mussel tissues were wet-ashed by nitric and percloric acid. Solutions of tissues were analysed by 2380 Perkin-Elmer AAS. Intercalibration homogenate sample (IAEA -142/ TM) was used as a quality control for the analytical methodology. The concentrations of some heavy metals (Pb, Cu, Zn) in the soft tissues of M. galloprovincialis were determined separately from different regions of Northern Turkish Aegean Sea. The Average levels of heavy metals in mussels are given. It can be seen from the table that there are significant differences in metal concentrations according to

  7. 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

  8. Field‐based validation of a diagenetic effect on G. ruber Mg/Ca paleothermometry: Core top results from the Aegean Sea (eastern Mediterranean)

    OpenAIRE

    Kontakiotis, George; Mortyn, Peter Graham; Antonarakou, Assimina; Martínez Botí, M. A.; Triantaphyllou, Maria V.

    2011-01-01

    Recent work across the Mediterranean Sea has illustrated the salinity and overgrowth effects on planktonic foraminiferal Mg/Ca, which potentially confound the use of this as a temperature proxy for paleoceanographic reconstructions. To test and verify these effects, we present new Aegean Sea results which reveal Mg/Ca values that were unreasonably high to be explained by temperature or salinity variations alone, confirming that foraminiferal Mg/Ca is affected by diagenesis. We have specifical...

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

    International Nuclear Information System (INIS)

    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 137Cs, 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)

  10. Radiation dose assessment for 137Cs from fish in the Aegean Sea before and after the Chernobyl accident

    International Nuclear Information System (INIS)

    The effective doses in fish from the Aegean Sea were calculated for the nuclide 137Cs covering the period 1975-1982. The effective dose varies between 3x10-5 and 10x10-5 mSv y-1 for adults and 14x10-5 to 56x10-5 y-1 for children, while the cumulative effective dose for the period 1975-1982 equals to 40.86x10-5 and 229.57x10-5 for adults and children of 10 y old, resp. When compared to doses derived from the Chernobyl accident (May 1986) it was found that the additional dose incurred by Greek individuals in May 1986 was approximately equal to the cumulative dose of 8 y contribution period (1975-1982) for adults and to a year's contribution for children of 10 y old. (author) 9 refs.; 3 figs

  11. Numerical simulations of tsunami generated by underwater volcanic explosions at Karymskoye lake (Kamchatka, Russia and Kolumbo volcano (Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    M. Ulvrová

    2013-11-01

    Full Text Available Increasing human activities along the coasts of the world arise the necessity to assess tsunami hazard from different sources (earthquakes, landslides, volcanic activity. In this paper, we simulate tsunamis generated by underwater volcanic explosions from (1 a submerged vent in a shallow water lake (Karymskoye Lake, Kamchatka, and (2 from Kolumbo submarine volcano (7 km NE of Santorini, Aegean Sea, Greece. The 1996 tsunami in Karymskoye lake is a well-documented example and thus serves as a case-study for validating the calculations. The numerical model reproduces realistically the tsunami runups measured onshore. Systematic numerical study of tsunamis generated by explosions of Kolumbo volcano is then conducted for a wide range of energies. Results show that in case of reawakening, Kolumbo volcano might represent a significant tsunami hazard for the northern, eastern and southern coasts of Santorini, even for small-power explosions.

  12. 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.

  13. Car-borne and on foot scintillometer survey of the Aegean Sea Islands (Greece). Pt. B

    International Nuclear Information System (INIS)

    This study being the continuation of a previous report (DEMO 84/8G) gives a detailed description and interpretation of the results of the radiometric survey in general and of the radiometric anomalies more particularly of fifty-one Aegean islands of Greece. The main radiometric anomalies from the point of view of great surface extension and/or high concentration in soluble and/or total uranium are indicated. Further estimation and investigation of the proven uraniferous regions where such anomalies have been traced are suggested. (author)

  14. 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,...

  15. 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,...

  16. 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,...

  17. Chromosome mutagenesis in populations of aquatic biota in the Black Sea, Aegean Sea and Danube and Dnieper rivers, 1986-1989

    International Nuclear Information System (INIS)

    We studied the level of structural mutagenesis in the reproductive and somatic cells of aquatic biota of various taxa from natural populations of neustic and benthic communities in the Black and Aegean Seas and the Dnieper and Danube rivers between 1986 and 1989. The cytogenetic research covered embryos, larvae and adult worms of Nereidae, Naididae, Tubificidae and Turbellaria, adult Sagitta setosa, young Bivalvia molluscs, embryos of Mysidacea, and growing roe of Engraulis encrasicholus, Sprattus sprattus, Diplodus annularis, Mullus barbatus, Trachurus trachurus, Scophthalmus maeoticus, Abramis brama, Blicca bjoerkna, Rutilus rutilus and Stizostedion lucioperca. It was established that aquatic biota in the open waters of the Black and Aegean Seas had a lower level of chromosome mutagenesis than representatives of the fluvial communities. The intensity of mutagenesis was compared with the data published in the literature on radioactive contamination/chemical pollution of the aqueous medium in these areas. The paper sets out statistical regularities in chromosome mutagenesis (inter-individual variability in the chromosome aberration rate and distribution of chromosome damage in cells), noting different patterns of chromosome aberration distribution among cells. On the basis of a large quantity on our own data from field and experimental cytogenetic studies involving aquatic biota, the paper considers the possibility of using - for the purposes of radiochemical-ecological monitoring - chromosome damage distribution in cells as an indicator of whether mutagens are radiation-related or not. (author)

  18. Assessment of ENSEMBLES regional climate models for the representation of monthly wind characteristics in the Aegean Sea (Greece): Mean and extremes analysis

    Science.gov (United States)

    Anagnostopoulou, Christina; Tolika, Konstantia; Tegoulias, Ioannis; Velikou, Kondylia; Vagenas, Christos

    2013-04-01

    The main scope of the present study is the assessment of the ability of three of the most updated regional climate models, developed under the frame of the European research project ENSEMBLES (http://www.ensembles-eu.org/), to simulate the wind characteristics in the Aegean Sea in Greece. The examined models are KNMI-RACMO2, MPI-MREMO, and ICTP - RegCM3. They all have the same spatial resolution (25x25km) and for their future projections they are using the A1B SRES emission scenarios. Their simulated wind data (speed and direction) were compared with observational data from several stations over the domain of study for a time period of 25 years, from 1980 to 2004 on a monthly basis. The primer data were available every three or six hours from which we computed the mean daily wind speed and the prevailing daily wind direction. It should be mentioned, that the comparison was made for the grid point that was the closest to each station over land. Moreover, the extreme speed values were also calculated both for the observational and the simulated data, in order to assess the ability of the models in capturing the most intense wind conditions. The first results of the study showed that the prevailing winds during the winter and spring months have a north - northeastern or a south - south western direction in most parts of the Aegean sea. The models under examination seem to capture quite satisfactorily this pattern as well as the general characteristics of the winds in this area. During summer, winds in the Aegean Sea have mainly north direction and the models have quite good agreement both in simulating this direction and the wind speed. Concerning the extreme wind speed (percentiles) it was found that for the stations in the northern Aegean all the models overestimate the extreme wind indices. For the eastern parts of the Aegean the KNMI and the MPI model underestimate the extreme wind speeds while on the other hand the ICTP model overestimates them. Finally for the

  19. 210Po in mussels (Mytilus galloprovincialis, L. 1758) and sediments at Aegean Sea Turkish coast using alpha spectrometry

    International Nuclear Information System (INIS)

    In the marine environment 210Po is largely produced from the decay of 210Pb deposited from the atmosphere. Although they exist everywhere in the environment at the same time, the concentration of these radionuclides in river-estuarine systems may vary widely due to geology of the watershed and chemical weathering conditions. Moreover, natural levels of these radionuclides in aquatic ecosystems increased from phosphate, fossil fuel, oil industries and use of artificial fertilizers. Several studies have demonstrated that the natural alpha emitting radionuclide 210Po is accumulated to exceptionally high levels in tissues of a variety of marine organisms, well above levels of the parent radionuclide 210Pb. The behaviour of 210Po in the ocean differs that of 210Pb, especially because of the higher affinity of 210Po for organic matter. The Turkish coastal zone of the Aegean Sea has been heavily industrialized in the last 25 years resulting in a considerable input of wastes to the coastal marine ecosystem. Fish and other edible marine organisms consumption is relatively higher at the region than at other parts of Turkey, therefore it is important to determine the additional dietary radiation dose received by population originating seafood. The information on levels and distribution of natural radionuclides is however very rare because there exists limited number of investigations conducted on this coast line. For this reason, an IAEA Research Contract Project (B5-TUR-31834) has been started by the Institute for the Turkish coast of the Aegean Sea. In this work 210Po and 210Pb measurements are realised using alpha spectrometry after radiochemical deposition techniques for which the details are given elsewhere. The sampling stations are selected at the sites where there exist intense industrial activities nearby. Canakkale (Dardanel), Ayvalik, Foca, Izmir Bay and Goekova Bay were chosen as study areas. Goekova Bay is attributed special importance because it has been

  20. Distribution and relationship of mercury, lead and cadmium in selected tissues of Pagellus erythrinus from the Aegean Sea

    International Nuclear Information System (INIS)

    Among the more dangerous pollutants are the so-called heavy metals introduced into marine environment by waste and sewage. Fish are widely used as sentinels of contamination in aquatic environmental. The study area extends from Edremit Bay in the north to Fethiye in the southeastern Aegean. The present environmental problems are due to unmanaged shipping activity, river run-off and untreated sewage discharge by coastal settlements, dumping of toxic and industrial wastes from the western part of Turkey. Red Pandora (Pagellus erythrinus) is very important commercial species and is most consumed ones, so it is selected in this study. Fish tissues (muscle, liver) are commonly used as indicators of degree of contamination of marine environment with metals. metal concentrations were studied in selected marine fishes in the Aegean Sea. Biota samples were collected by trawling from sampling stations in May 1996, September 1997, January and July 1998. Biota tissue is digested in microwave digestion system. All the analyses are performed by atomic absorption spectrophotometer. Hg is measured by cold vapour technique, Cd, Pb are determined by graphite furnace. Intercalibration fish homogenate samples (from IAEA, Monaco) were used as a control for the analytical methods. Statistical analysis was performed using Statistica software. The mean concentrations and standards errors of metals are summarized. The concentrations found in muscle and liver tissues varied, with Hg ranging from 16-716 and 125-5451, Cd ranging from nd-9.6 and 1.4-2245, Pb ranging from nd-1397 and nd-8311 μg kg-1, respectively. There are no significant correlations between fork lengths and metal concentrations.is showed that levels in July differed significantly from January. Mercury is showed that levels at Goecek (9) differed significantly from Izmir Bay (3) and Kusadasi (5). The One-way ANOVA test showed the statistically significant seasonal differences for Cd (p-1 in the western Mediterranean

  1. Review of variations in Mw < 7 earthquake motions on position and TEC (Mw = 6.5 Aegean Sea earthquake sample)

    Science.gov (United States)

    Yildirim, Omer; Inyurt, Samed; Mekik, Cetin

    2016-02-01

    Turkey is a country located in the middle latitude zone, where tectonic activity is intensive. Recently, an earthquake of magnitude 6.5 Mw occurred offshore in the Aegean Sea on 24 May 2014 at 09:25 UTC, which lasted about 40 s. The earthquake was also felt in Greece, Romania, and Bulgaria in addition to Turkey. In recent years, ionospheric anomaly detection studies have been carried out because of seismicity with total electron content (TEC) computed from the global navigation satellite system's (GNSS) signal delays and several interesting findings have been published. In this study, both TEC and positional variations have been examined separately following a moderate size earthquake in the Aegean Sea. The correlation of the aforementioned ionospheric variation with the positional variation has also been investigated. For this purpose, a total of 15 stations was used, including four continuously operating reference stations in Turkey (CORS-TR) and stations in the seismic zone (AYVL, CANA, IPSA, and YENC), as well as international GNSS service (IGS) and European reference frame permanent network (EPN) stations. The ionospheric and positional variations of the AYVL, CANA, IPSA, and YENC stations were examined using Bernese v5.0 software. When the precise point positioning TEC (PPP-TEC) values were examined, it was observed that the TEC values were approximately 4 TECU (total electron content unit) above the upper-limit TEC value at four stations located in Turkey, 3 days before the earthquake at 08:00 and 10:00 UTC. At the same stations, on the day before the earthquake at 06:00, 08:00, and 10:00 UTC, the TEC values were approximately 5 TECU below the lower-limit TEC value. The global ionosphere model TEC (GIM-TEC) values published by the Centre for Orbit Determination in Europe (CODE) were also examined. Three days before the earthquake, at all stations, it was observed that the TEC values in the time period between 08:00 and 10:00 UTC were approximately 2 TECU

  2. 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.

  3. Occurrence and partitioning of endocrine-disrupting compounds in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece

    International Nuclear Information System (INIS)

    Highlights: ► Add knowledge regarding the fate of EDCs in marine environment. ► Nonylphenols and its ethoxylates are the dominant pollutants. ► EDCs originated from mainly from river and urban effluents. ► The partition coefficients negatively correlated to suspended particulate matter. ► Mussels exhibited low bioconcentartion factors for nonylphenol and octylphenol. - Abstract: An integrated study was conducted to determine the presence of phenolic and steroid endocrine-disrupting compounds (EDCs), in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece. Seawater, suspended particulate matter, sediments and biota were examined for nonylphenol, octylphenol, their mono- and diethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol and 17 α-ethynylestradiol. Phenolic compounds were detected in all of the compartments, with nonylphenol and its ethoxylates being the dominant pollutants. The occurrence of nonylphenol in sediments presents a significant risk to the biota. Mussels exhibited relatively low concentrations and low bioconcentration factors for NP and OP. The effect of terrestrial sources of the EDCs on the marine environment is discussed. The influence of suspended particulate matter and organic carbon in the partition of the EDCs between the dissolved and the particulate phase was investigated.

  4. Benthic foraminiferal response to heavy metal pollution in Izmir Bay (Eastern Aegean Sea)

    International Nuclear Information System (INIS)

    were stained with Rose Bengal to help recognize the living individuals. After drying and sieving the residues through a 250 mm mesh, the foraminifers were picked up and examined under a binocular microscope. 1) We identified 67 foraminifer and 22 ostracod species 2) The most polluted area is the Inner Bay where the number of species decreases 3) The most abundant species at the study area are Ammonia tepida, Elphidium crispum, Ampicoryna scalaris, Noniella turgida and Nonion depressulum. The last two species have been already identified in the Northern Aegean and these species were found in the Gulf of Izmir in this study due to northern Aegean waters flowing into the Gulf of Izmir 4) Test deformities are observed in Ammonia tepid and Adelosina mediterranensis 5) Living specimens are limited in number 6) Elphidium crispum is correlated with Hg (R= 0.844), while negative correlation was found between Elphidium crispum and Cr (R= -0.637). Positive correlations were observed between Ni- Amphycoryna scalaris (R= 0.484), and Ni-Noniella turgida (R= 0.455), Mn-Noniella turgida (R0.558) 7) The factors determining the distribution of Foraminiferal assemblages are organic pollutants. The high species number at Gulbahce Bay and Gediz River effluents verify this conclusion

  5. A review of tectonics and sedimentation in a forearc setting: Hellenic Thrace Basin, North Aegean Sea and Northern Greece

    Science.gov (United States)

    Maravelis, A. G.; Boutelier, D.; Catuneanu, O.; Seymour, K. St.; Zelilidis, A.

    2016-04-01

    Exposure of the forearc region of the North Aegean Sea, Greece, offers insight into evolving convergent margins. The sedimentary fill of the Thrace Basin during the Late Eocene to Oligocene time provides a record of subduction-driven processes, such as growth of magmatic arcs and construction of accretionary complexes. This large sediment repository received sediment from two sources. The southern (outboard) basin margin reflects the active influence of the exhumed accretionary prism (e.g. Pindic Cordillera or Biga peninsula), while the northern (inboard) margin records the effect of the magmatic arc in the Rhodope region. The forearc basin sedimentary fills shoal upward into shallow-marine strata but are dominated mainly by deep-marine facies. The depositional trend and stacking pattern are dominated by progradational patterns. This trend, which is observed in both basin margins, is related to tectonic deformation rather than sea-level fluctuations. Additional evidence for this tectonic uplift comes from the backstripping analysis. The accretionary complex provided material into the forearc basin. This material was transported northeast and formed a sand-rich turbidity system that evolved upslope into shallow-marine deposits. Stratigraphic data indicate that this turbidity system exhibits a successive landward (inboard) migration of the depocenter. Provenance data utilizing sandstone petrography, conglomerate clast composition, and bulk-rock geochemistry suggest that this system reflects an increased influx of mafic material into the basin. Volcanic arc-derived material was transported south and east and accumulated in deep-marine settings. Both stratigraphic and provenance data indicate a seaward (outboard) migration of the basin depocenter and a significant increase in felsic detritus into the forearc.

  6. 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.

  7. Abundance and Distribution of Zooplankton in CoastalArea of Gokceada Island (Northern Aegean Sea)

    OpenAIRE

    Tarkan, Abmet Nuri

    2000-01-01

    Abstract This study was carried out in order to determine population of zooplankton in the coastal waters of Gokgeada. At the 10 stations of those depths ranging from 20 in to 30 in, the measurements of temperature, salinity and oxygen were made, and zooplankton samples were collected vertically and horizontally using plankton nets. In the neritic waters of the island, the effects of the Black Sea waters through Dardanelles were observed and zooplankton species of the Black Sea found. F...

  8. 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.

  9. 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.

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

    International Nuclear Information System (INIS)

    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)

  11. Zircon U-Pb, O, and Hf isotopic constraints on Mesozoic magmatism in the Cyclades, Aegean Sea, Greece

    Science.gov (United States)

    Fu, Bin; Bröcker, Michael; Ireland, Trevor; Holden, Peter; Kinsley, Leslie P. J.

    2015-01-01

    Compared to the well-documented Cenozoic magmatic and metamorphic rocks of the Cyclades, Aegean Sea, Greece, the geodynamic context of older meta-igneous rocks occurring in the marble-schist sequences and mélanges of the Cycladic Blueschist Unit is as yet not fully understood. Here, we report O-Hf isotopic compositions of zircons ranging in age from ca. 320 Ma to ca. 80 Ma from metamorphic rocks exposed on the islands of Andros, Ios, Sifnos, and Syros with special emphasis on Triassic source rocks. Ion microprobe (SHRIMP II) single spot oxygen isotope analysis of pre-Cretaceous zircons from various felsic gneisses and meta-gabbros representing both the marble-schist sequences and the mélanges of the study area yielded a large range in δ18O values, varying from 2.7 ‰ to 10.1 ‰ VSMOW, with one outlier at -0.4 %. Initial ɛHf values (-12.5 to +15.7) suggest diverse sources for melts formed between Late Carboniferous to Late Cretaceous time that record derivation from mantle and reworked older continental crust. In particular, variable δ18O and ɛHf( t) values for Triassic igneous zircons suggest that magmatism of this age is more likely rift- than subduction-related. The significant crustal component in 160 Ma meta-gabbros from Andros implies that some Jurassic gabbroic rocks of the Hellenides are not part of SSZ-type (supra-subduction zone) ophiolites that are common elsewhere along the margin of the Pelagonian zone.

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

    Science.gov (United States)

    Aravadinou, Eirini; Xypolias, Paraskevas; Chatzaras, Vasileios; Iliopoulos, Ioannis; Gerogiannis, Nikolaos

    2015-10-01

    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-preserved eclogites and blueschists. Our data show that the early, main phase (D2) of ductile deformation in the CBU occurred synchronous with the transition from prograde to close-to-peak retrograde conditions. This deformation phase took place at middle Eocene and is related to ESE-directed thrusting that emplaced the metavolcano-sedimentary subunit over the Marble subunit. The subsequent exhumation-related (D3) deformation is characterized by gently NE-plunging folds and NE-directed contractional shear zones that formed parallel to the axial planes of folds. NE-directed shearing occurred under blueschist and transitional blueschist-/greenschist-facies conditions during late Eocene-Oligocene and caused the restacking of the early nappe pile. We suggest that a mechanism of ductile extrusion of the CBU in a tectonic setting of net compression could explain better the recorded exhumation-related deformation than a mechanism of syn- and post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW-(E)SE at Late Cretaceous-middle Eocene to (E)NE-(W)SW at late Eocene-Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.

  13. Assessment of SMOS Salinity and SST in the Aegean Sea (Greece) and correlations with MODIS SST measurements. Exploring the SSS and SST correlation to 137Cs inventory

    Science.gov (United States)

    Sykioti, Olga; Florou, Heleni

    2014-05-01

    A program concept has been developed to utilize sea surface salinity (SSS) and sea surface temperature (SST) information for the inventory of artificial radionuclides, which are conservative and part of the sea salinity. As a pilot study, activity concentrations of 137Cs in the Aegean Sea (Greece) are combined to SMOS and other satellite data so as to develop an innovative tool for the remote radioactivity detection either for routine observations and emergency recordings. The presented first results are a part of an effort to attempt for the integration in space and time of field measurements to the respective satellite observations of salinity variations by model simulations, which might be also applicable for the prediction of the radiological impact of potential accidental events. The presented results involve the first assessment of SMOS SSS and SST measurements over the Aegean Sea. SMOS measurements are averaged over a surface of 40x40 sq km at an average distance of 100 km from the coastline. For this reason, totally thirty nine pixels from SMOS Level 2 data cover part of the Aegean Sea. Two time series are created that include all available measurements spanning December 2011 to current date, from descending and ascending passes, each one representing an acquisition frequency of about three days. The average SSS values in the Aegean Sea are 37-38psu following no distinct seasonal pattern. A general trend of increasing values is observed from north to south. Noise and uncertainty in the measurements are most probably due to land and RFI contamination. High island density is combined with radiofrequency interferences generated by illegal man-made emissions. The latter is a detected common issue in specific areas worldwide, such as the Mediterranean Sea. On the other hand, SST follows a clear typical seasonal variation pattern with maximum values observed in August and minimum ones around March and a general trend of increasing values from north to south

  14. Levels of 210Po in some commercial fish species consumed in the Aegean Sea coast of Turkey and the related dose assessment to the coastal population

    International Nuclear Information System (INIS)

    Concentrations of 210Po were determined in the edible muscle tissue of five species of marine fish: Sardine (Sardine plichardus) and Anchovy (Engraulis encrasicolus), Red mullet (Mullus barbatus), Horse mackerel (Trachurus trachurus) and Gilt-head sea bream (Sparus aurata) collected from five stations in the Aegean Sea Region of Turkey during the fishery season 2010. The 210Po concentrations in the fish samples were found to vary from not detected levels to 389 ± 45 Bq kg−1 dry wt. These variations in 210Po content in different species are probably due to differences in metabolism and feeding patterns. The highest levels for 210Po were observed in Anchovy (E. encrasicolus) species. -- Highlights: ► This study was determined the 210Po levels in the fish. ► Different fish species were collected in the Turkish coast of Aegean Sea. ► Higher 210Po concentrations were found in Anchovy. ► The annual dose from the consumption of the fish samples was calculated. ► The ingestion dose was found in the range 0.041–14.66 μSv y−1

  15. 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.

  16. Depositional environment, foraminifer content and ESR ages of Quaternary Gediz Delta Sediments (Eastern Aegean Sea, İzmir-Western Turkey)

    Science.gov (United States)

    Gökçe Benli, Ekin; Aydın, Hülya; İşintek, İsmail; Engin, Birol; Şengöçmen, Berna

    2016-04-01

    Sediments and fossil content of Gediz Delta (Eastern Aegean Sea - İzmir) were examined based on the drilling core samples of the YSK-C and SK-246 drilling. W-SW part of the Delta is represented by continental delta sediments up to 6 meters and shallow marine detritic sediments up to 35 meters in the YSK-C drilling. Continental part consists of an soiled, graveled, muddy and sandy sediment in terms of rich organic substance. As for marine part, it consists of bioclast, muddy, fine graveled sand and by repetition of pebble, sand and bioclast bearing mud layers. Bioclasts comprise of bivalvia, echinoid, ostracod, gastropod, foramifer and bryozoa fragments. Benthic foraminiferal fauna determinated in the marine levels are represented by 55 bethic, 2 planktonic species. These foraminifers and bioclasts reflect that the W-SW part of the delta, has been occured in marine conditions between 8-31m deep. E-NE part of the delta is generally represented by continental sediments up to 43.5m in SK-246 drilling. In addition, it includes marine levels in 18-19 m, 23-24 m and 36-37,5 m intervals. Continental sediments of E-NE part is generally represented by calcareous and sandy mud rocks which mostly includes ash, tuff, and pebble derived from Neogene volcanic rocks. As for marine levels, it is composed of calcareous mud stones and calcareous clay stones including very thin gastropod, bivalvia and ostracod in 18- 19 and 36-37.5 meters whereas it is represented by sandy mud stones including a great deal of bentic foraminifer, bivalvia, bryozoa, echinoid, gastropod in 23-24 metres. Thus show that E-NE part of the delta is usually in continental condition but it is occasionally covered by sea. In aging studies of YSK-C core done by ESR method, age of 8-9 m interval is determined to be 11. 376 ± 0,067 Ka; however ages of 10-11m and 24-25 m intervals are revealed to be 16.466 ± 0,016 Ka and 15.344 ± 0,021 Ka respectively; finally age of 25-26 m interval is found to be 19.995 ± 0

  17. 210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

    International Nuclear Information System (INIS)

    In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210Po, in the marine environment. 210Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210Po and 210Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their 210Po and 210Pb content. The 210Po and 210Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg−1 dry weight (dw) and from 1.0 ± 0.3 Bq kg−1 to 35 ± 4.0 Bq kg−1 (dw), respectively. There were no significant differences in the activity concentrations of 210Po and 210Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210Po to humans was calculated to be 10,530 μSv year−1.

  18. 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

  19. April 16, 2015 Crete Island Earthquake (Mw=5.9) Series and its Seismotectonic Significance, Southern Aegean Sea

    Science.gov (United States)

    Yalçın, Hilal; Kürçer, Akın; Gülen, Levent

    2016-04-01

    The active deformation of the southern Aegean Sea is a result of the northward motion of the African and Arabian Plates with respect to the Eurasian Plate in the Eastern Mediterranean Region. The Hellenic subduction zone plays a key role in the active tectonics of the region. On 16 April, 2015, a moderate earthquake occurred on the eastern part of Hellenic arc (south of Crete island), with a moment magnitude of Mw=5.9. A series of aftershocks were occurred within four months following the mainshock, which have magnitudes varying from Mw = 3.4 to 5.4. Source parameters of the 16 April 2015 earthquake have been modeled in order to reveal the regional stress tensor and the tectonic style of the region. In this study, the source parameters of the main shock and 36 aftershocks that have magnitudes M≥3.4 have been determined and modeled by seismic moment tensor waveform inversion method developed by Sokos and Zahradnik (2006) algorithm using the near-field and regional waveforms. The depth of earthquakes are varied from 2 to 61 km. Stress tensor can describe reliably principle stress axes (σ1, σ2, σ3), their relative size and stress field variations. Stress tensor inversions have been carried out using the Micheal method (1984, 1987). In this study, 16 April 2015 Crete Earthquake mainshock (Mw=5.9), a total of 36 earthquake moment tensor solutions that belong to the Crete earthquake sequence and 24 earthquake moment tensor solutions of previous main shocks in the region have been compiled and used in the stress inversion calculation. Orientations of σ1, σ2 and σ3 were computed and the principal directions are projected onto a lower hemisphere Wulff net. The best fit was attained for Phi = 0.38+/‑0.13609 and indicated that the stress regime revealed strike-slip faulting with reverse component and for the azimuth and plunge pair of (-161.6°, 21.7°) for σ1, (-11.1°, 65.4°) for σ2 and (103.8°, 10.9°) for σ3. At the final step of the study, Gutenberg and

  20. Vertical and wide-angle seismic exploration of crustal structure, and the active evolution of the North Aegean Trough between the Sea of Marmara and Gulf of Corinth

    Science.gov (United States)

    Sachpazi, M.; Vigner, A.; Laigle, M.; Hirn, A.; Roussos, N.

    2003-04-01

    The North Aegean Trough (NAT), which is the deepest among Aegean marine troughs, is bordered by the termination of the North Anatolian Fault, and thus marks the interaction of this strike-slip fault with mainland Greece and the extensional Aegean domain. In the development of academic exploration of active regions at the scale of the whole crust, with marine multichannel seismics (MCS), the STREAMERS acquisition almost ten years ago provided a first hint of the feasibility there and in other parts of the Aegean and Ionian seas (Sachpazi et al., Tectonophysics 1996), and a template for later MCS and coincident wide-angle reflection surveying. These profiles were acquired by the French N/O Nadir, with an only 96-channel streamer 2.4 km length, and with an only 840 cu. in. generator capacity of a 8 gun array, but for the first time shot in the "single-bubble" mode that was developed in this survey. With respect to the present standard set by 2001 cruises in the Gulf of Corinth (US R/V Maurice Ewing, Taylor et al. this meeting) and in the Sea of Marmara (French N/O Nadir, Hirn et al., EGS 2002 and this meeting) this was a 2 to 3 times shorter streamer cable, a 2 to 4 times smaller number of hydrophone groups, and a 10 to 3 times smaller source. The SEISGREECE survey, with a source 3 times that of STREAMERS but other parameters as modest, explored the Gulf of Corinth and the Cyclades and added profiles in the North Aegean to this early attempt. A first result of merging the two surveys was to lend credence to possible structures detected by the first single profile. This revealed an active, recent normal-fault imaged down to 10 km depth, that cuts at a N 110°E strike the northern side of the NAT (Laigle et al., Geology, 2000). Indeed although processing has been hampered by the modest streamer length and only 16 or 24-fold coverage, the data now resolve clearly the sedimentary structure, image the basement, detect intra-basement faults, an upper crustal reflective zone

  1. The Aegean Sea oil spill in the Galicia Coast (NW Spain). I. Distribution and fate of the crude oil and combustion products in subtidal sediments

    International Nuclear Information System (INIS)

    The spatial distribution and fate of petrogenic and pyrogenic hydrocarbons in coastal sediments following the Aegean Sea oil spill (Galicia, NW Spain) was investigated through a detailed study of chemical markers. Alkanes and acyclic isoprenoid hydrocarbons were degraded within six months of the accident, but triterpane and sterane distributions were still detectable and were useful in monitoring, respectively, the oil source and weathering. Aromatic steranes were also useful source indicators, and oil degradation was clear from the decrease of certain alkyl dibenzothiophene and phenanthrene isomers. The pyrogenic polycyclic aromatic hydrocarbons produced in the tanker wreck were found more persistent than the petrogenic ones. However, the presence of the oil in the sediments was recognized even one year after the accident and was found particularly preserved in the subsurface layers. (author)

  2. Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

    Science.gov (United States)

    Filippidi, A.; Triantaphyllou, M. V.; De Lange, G. J.

    2016-07-01

    Present-day bottom-water ventilation in the Eastern Mediterranean basin occurs through deep-water convection originating from the two marginal basins, i.e. Adriatic and Aegean Seas. In the paleo record, long periods of enhanced deep-water formation have been alternating with shorter periods of reduced deep-water formation. The latter is related mainly to low-latitude humid climate conditions and the enhanced deposition and preservation of organic-rich sediment units (sapropels). This study focuses on sedimentary archives of the most-recent sapropel S1, retrieved from two sites under the direct influence of the two deep-water formation areas. Restricted oxygen conditions have developed rapidly at the beginning of S1 deposition in the Adriatic site, but bottom-water conditions have not persistently remained anoxic during the full interval of sapropel deposition. In fact, the variability in intensity and persistence of sedimentary redox conditions at the two deep-water formation sites is shown to be related to brief episodes of climate cooling. In the Adriatic site, sapropel deposition appears to have been interrupted twice. The 8.2 ka event, only recovered at the Adria site, is characterized by gradually increasing suboxic to possibly intermittently oxic conditions and decreasing Corg fluxes, followed by an abrupt re-establishment of anoxic conditions. Another important event that disrupted sapropel S1 formation, has taken place at ca. 7.4 cal ka BP. The latter event has been recovered at both sites. In the Adriatic site it is followed by a period of sedimentary conditions that gradually change from suboxic to more permanently oxic, as deduced from the Mn/Al pattern. Using the same proxy for suboxic/oxic sedimentary redox conditions, we observe that conditions in the Aegean Sea site shift to more permanently oxic from the 7.4 ka event onwards. However, at both sites the accumulation and preservation of enhanced amounts of organic matter have continued under these

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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.

  5. Review of variations in Mw < 7 earthquake motions on position and tec (Mw = 6.5 aegean sea earthquake sample)

    OpenAIRE

    Yildirim, O; Inyurt, S.; C. Mekik

    2015-01-01

    Turkey is a country located in Middle Latitude zone and in which tectonic activity is intensive. Lastly, an earthquake of magnitude 6.5Mw occurred at Aegean Sea offshore on date 24 May 2014 at 12:25 UTC and it lasted approximately 40 s. The said earthquake was felt also in Greece, Romania and Bulgaria in addition to Turkey. In recent years seismic origin ionospheric anomaly detection studies have been done with TEC (Total Electron Contents) generated fro...

  6. Old stories and lost pieces of the Eastern Mediterranean puzzle: a new approach to the tectonic evolution of the Western Anatolia and the Aegean Sea

    Science.gov (United States)

    Yaltırak, Cenk; Engin Aksu, Ali; Hall, Jeremy; Elitez, İrem

    2015-04-01

    During the last 20 or so years, the tectonic evolution of Aegean Sea and Western Anatolia has been dominantly explained by back-arc extension and escape tectonics along the North Anatolian Fault. Various datasets have been considered in the construction of general tectonic models, including the geometry of fault patterns, paleomagnetic data, extensional directions of the core complexes, characteristic changes in magmatism and volcanism, the different sense of Miocene rotation between the opposite sides of the Aegean Sea, and the stratigraphy and position of the Miocene and Pliocene-Quaternary basins. In these models, the roles of the Burdur-Fethiye Shear Zone, the Trakya-Eskişehir Fault Zone, the Anaximander Mountains and Isparta Angle have almost never been taken into consideration. The holistic evaluation of numerous land and marine researches in the Aegean Sea and western Anatolia suggest the following evolutionary stages: 1. during the early Miocene, Greece and western Anatolia were deformed under the NE-SW extensional tectonics associated with the back-arc extension, when core complexes and supra-detachment basins developed, 2. following the collision of the Anaximander Mountains and western Anatolia in early Miocene , the Isparta Angle locked this side of the western arc by generating a triangle-shaped compressional structure, 3. while the Isparta Angle penetrated into the Anatolia, the NE-striking Burdur-Fethiye Shear Zone in the west and NW-striking Trakya-Eskişehir Fault Zone in the north developed along the paleo-tectonic zones , 4. the formation of these two tectonic structures allowed the counterclockwise rotation of the western Anatolia in the middle Miocene and this rotation removed the effect of the back-arc extension on the western Anatolian Block, 5. the counterclockwise rotation developed with the early westward escape of the Western Anatolian reached up to 35-40o and Trakya-Eskişehir Fault Zone created a total dextral displacement of about 200

  7. Spatial and temporal variability of 210Po and 210Pb in mussels (Mytilus galloprovincialis) at the Turkish Coast of the Aegean Sea

    International Nuclear Information System (INIS)

    In this study, the activity concentrations of 210Po and 210Pb were determined in mussel samples (Mytilus galloprovincialis) collected from the Turkish coast of the Aegean Sea. The samples were collected seasonally for a period of two years (2004-2006) at six coastal stations (Canakkale, Dikili, Foça, Çe°me, Didim, Bodrum). Mussels were separated into several groups according to their size (1-4, 4-6, >6 cm). The results showed that 210Po concentrations in mussels varied between 53±4 and 1960±60 Bq kg-1 dw. The highest activity 210Po concentrations were determined in winter samples of mussels with a shell length of 4-6 cm from Didim. In general, it was observed that the 210Pb concentration levels in mussels were lower than 210Po concentrations. The 210Po/210Pb activity concentration ratios exceeded unity for all mussel samples and averaged 26.0. The inter-site difference seen in 210Po concentrations can be due to both the natural background levels of sites and industrial activities. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  9. A new metamorphic map of Syros Island (Aegean Sea, Greece): implications for strain localization from prograde to retrograde path

    Science.gov (United States)

    Laurent, Valentin; Jolivet, Laurent; Roche, Vincent; Augier, Romain; Scaillet, Stéphane; Cardello, Luca

    2015-04-01

    The Aegean domain is located in the eastern part of the Mediterranean and has undergone a complex Alpine history that can be summarized in two successive episodes: (1) The formation of the Hellenides-Taurides belt due to the convergence between Eurasia and Africa; during this episode, a series of oceanic and continental nappes entered the subduction zone and were thrust on top of each other in a HP-LT metamorphic context. (2) From 35-30 Ma, an acceleration of slab retreat led to the collapse of the belt and the formation of large detachments. The island of Syros (Cycladic Blueschists belt) is worldwide known for the excellent preservation of HP-LT tectonic and metamorphic features associated with these processes, possibly providing one of the best places to study the deformation and metamorphic evolution of the subduction interface. Syros has recorded a complex deformation history during both the prograde and retrograde phase that resulted in the juxtaposition of two main units: (1) the Cycladic Blueschists Unit (CBU), and (2) the Vari unit cropping out in the SE of the island. Conflicting tectonic interpretations have been proposed to explain the evolution of the island, in part reflecting the lack of consensus about the detailed tectonic structure of the CBU. A new geological and metamorphic map of Syros is proposed to better characterize the different structures related to prograde and/or retrograde deformation stages. High-resolution field-mapping, combined with detailed structural-petrological observations, allows us to subdivide the CBU into three sub-units separated by major ductile shear zones. From top to bottom, these are: 1) the Kampos, 2) the Chroussa, and 3) the Posidonia units. Each of these units experienced similar peak eclogite-facies conditions (ca. 20 kbar - 550 °C), variably overprinted under blueschist- and greenschist-facies conditions across the nappe pile. New ductile structures have been discovered. Among those, a new large-scale top

  10. 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.

  11. Impact of recent Global Digital Bathymetry and Topography Models on geoid modelling: Results from two case studies in Balearic and Aegean Seas

    Science.gov (United States)

    Delikaraoglou, D.; Mintourakis, I.; Kallianou, F.

    2009-04-01

    geoid modelling of archipelagic (island) areas. We have concentrated in two test regions: (a) the Catalano-Balearic Sea (South of Spain in the NW Meditteranean), where adequate marine and land gravity data allow a detailed evaluation of our processing methodologies and their results and, (b) the Aegean Sea where the presence of many islands in varying distances from the mainland Greece and located on the continental shelf and/or divided by steep sea floor topography present some unique challenges for any high resolution geoid modelling efforts. For both test regions, we generated a combined DEM (C-DEM) using the IFREMER and SRTM 30 arcsec bathymetric data for the sea areas and SRTM 3 arcsec data for the surrounding land areas. In this contribution, we discuss various computational aspects relating to the so-called "Direct Topographical Effect" (DTE) and the "Indirect Topographical Effect" (ITE), the two most significant topographical effects that have to be evaluated when a precise geoid is being compiled. In addition, we outline the evaluation and the impact of the results obtained, especially with regard to the differences in the geoid models when different elevation data are used, and point out the main limitations and possibilities for further improvements in the use of the aforementioned satellite and terrestrial data for regional and local geoid mapping in coastal and island regions. Keywords: IFREMER, SRTM, terrain effects, free-air gravity anomalies, geoid modelling,Digital Bathymetry Models.

  12. The Effect of Sea Cucumber Holothuria tubulosa (G., 1788) on Nutrient and Sediment of Aegean Sea Shores

    OpenAIRE

    Dilek IOgoren-Emiroglu; Deniz Gunay

    2007-01-01

    The effects of sea cucumber, Holothuria tubulosa, on sediment of hypereutrophic conditions were investigated. Research was designed as two groups with 3 replicates. And data determined from sea cucumber groups were compared to that of the control. Water samples and sediment samples were analyzed three times in a week with respect to nitrogenous materials and organic carbon. The differences between the initial and final concentrations of % C, ammonium, nitrate and nitrite were significant (p&l...

  13. Remote radiological assessment in the marine environment: SMOS and MODIS observations combined to {sup 137}Cs activity concentrations in the Aegean Sea - Greece - Remote radiological assessment in the marine environment: SMOS observations combined TO Cs-137 activity concentrations in the Aegean Sea Greece

    Energy Technology Data Exchange (ETDEWEB)

    Florou, H.; Tzempelikou, E. [NCSR ' Demokritos' , Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, Aghia Paraskevi 15310, POB 60037, Attiki (Greece); Sykioti, O. [National Observatory of Athens, Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, Vas. Pavlou and I. Metaxa, 15236 Penteli, Greece, Athens (Greece); Evangeliou, N. [CEA-CNRS-UVSQ UMR 8212, IPSL/LSCE Gif-sur-Yvette Cedex (France); Mavrokefalou, G. [Harokopio University, Department of Geography, 70 El. Venizelou, Kallithea, 17671, Athens (Greece)

    2014-07-01

    The capability of ordinary earth-observational satellites to record changes of ecological parameters in the environment is well documented. Nevertheless, radionuclide dispersion cannot be detected by the installed devices directly. However, the levels of radionuclides in the marine environment, especially for the soluble ones, are associated with other physical and chemical parameters of the natural environment (e.g. temperature/evaporation, water density, salinity etc). It is well known that marine dynamic processes, like horizontal advection and vertical mixing, control distribution of radionuclides in waters. The water density controls the transport of water masses among basins, which results to trans-boundary radioactive contamination. On the other hand, salinity and temperature control the water density and consequently is a major parameter for the marine radiological assessment. Nevertheless, salinity is a critical index for weathering and anthropogenic influences in the marine environment such as rainfall, evaporation, river runoff, global fallout, accidental releases, inter-regional contamination through current circulation, which are potential impact sources for the marine environment. In the present study, the activity concentrations of {sup 137}Cs in the Aegean Sea Greece combined to SMOS data are treated and simulated to models as to develop an innovative tool for the remote radioactivity detecting either for routine observations and emergency recording. Besides, the integrated by space and time field measurements to the respective satellite observations of salinity variations will create a model, which might be also applicable for the prediction of the radiological impact of potential accidental events. This presentation is the first footprint of this research under the coordinated Project AOSMOS.4681 ESA, being carried out in NOA and NCSR'D'. (authors)

  14. Remote radiological assessment in the marine environment: SMOS and MODIS observations combined to 137Cs activity concentrations in the Aegean Sea - Greece - Remote radiological assessment in the marine environment: SMOS observations combined TO Cs-137 activity concentrations in the Aegean Sea Greece

    International Nuclear Information System (INIS)

    The capability of ordinary earth-observational satellites to record changes of ecological parameters in the environment is well documented. Nevertheless, radionuclide dispersion cannot be detected by the installed devices directly. However, the levels of radionuclides in the marine environment, especially for the soluble ones, are associated with other physical and chemical parameters of the natural environment (e.g. temperature/evaporation, water density, salinity etc). It is well known that marine dynamic processes, like horizontal advection and vertical mixing, control distribution of radionuclides in waters. The water density controls the transport of water masses among basins, which results to trans-boundary radioactive contamination. On the other hand, salinity and temperature control the water density and consequently is a major parameter for the marine radiological assessment. Nevertheless, salinity is a critical index for weathering and anthropogenic influences in the marine environment such as rainfall, evaporation, river runoff, global fallout, accidental releases, inter-regional contamination through current circulation, which are potential impact sources for the marine environment. In the present study, the activity concentrations of 137Cs in the Aegean Sea Greece combined to SMOS data are treated and simulated to models as to develop an innovative tool for the remote radioactivity detecting either for routine observations and emergency recording. Besides, the integrated by space and time field measurements to the respective satellite observations of salinity variations will create a model, which might be also applicable for the prediction of the radiological impact of potential accidental events. This presentation is the first footprint of this research under the coordinated Project AOSMOS.4681 ESA, being carried out in NOA and NCSR'D'. (authors)

  15. Effects of persistent organic pollutants on the thyroid function of the European sea bass (Dicentrarchus labrax) from the Aegean Sea, is it an endocrine disruption?

    OpenAIRE

    Schnitzler, Joseph; Koutrarkis, Emmanuil; Siebert, Ursula; Thomé, Jean-Pierre; Das, Krishna

    2008-01-01

    We evaluated the alterations of organochlorinated compounds such as polychlorobiphenyls (PCB), dichloro-diphenyl-dichloroethylene (DDE) and dichloro-diphenyl-trichloroethane (DDT) on the thyroid in wild and cultured sea bass (Dicentrarchus labrax) at environmental concentrations. These compounds influence the endocrine system of many fish species and are qualified as endocrine disruptors. The thyroid seems to be a target organ. Two alteration endpoints: the thyroid histology and the muscular ...

  16. Determination of 40K in Beach Sand and Seawater Samples at Sarımsaklı Beach of Aegean Sea (Turkey)

    OpenAIRE

    Hacıyakupoğlu, Sevilay; Tezsezer, Seyda; Orucoglu, Esra

    2011-01-01

    This study dealt with analyzing of naturally occurring 40K radioisotope in beach sand and seawater samples of Sarımsaklı beach at Aegean coastal region of Turkey and its contribution to natural radioactivity. By using gamma spectroscopy the mean radioactivity concentration was found as 1093.00 ± 115.07 Bq kg-1 for the beach sand and as 14.08 ± 3.50 Bq kg-1 for the seawater. The average external effective dose rate of beach sand was determined in air at 1 m above the ground as 45...

  17. The Aegean: A natural laboratory for tectonics

    International Nuclear Information System (INIS)

    The Aegean, a young and active tectonic region, is a natural laboratory for analyzing many tectonic processes that occur in backarc extensional regimes, and the correlation of these processes from landscape development to deeper mantle dynamics. Cenozoic development of the Aegean region was dominated by subduction beneath Europe and coeval upper plate extension modified by westward extrusion of Anatolia. Intraorogenic and backarc extension began during early Cenozoic time within the Balkans and NW Turkey during closure of the Vardar ocean. Extension was manifested by core complex formation and a change in volcanism caused by the evolution of the lithosphere and mantle wedge. Following a short period of local (?) shortening in ∼ early Miocene time, regional extension began and continued to the present. Within the Hellenides, E-W extension and the subduction zone migrated westward as thick and thin crustal units were progressively accreted and were complexly rotated up to 400 CW. Within the eastern Balkans and NW Turkey, N-S extension migrated westward and southward, and in the Aegean the volcanic arc and subduction zone migrated southward. Turkish crustal elements rotated complexly CCW, which in concert with the CW rotation in the Hellenides increased the curvature of the subduction zone and lengthened the orogen causing greater subsidence and extension in the Aegean Sea. Westward extrusion of Anatolia from the Arabian collision zone was enhanced by slab roll back in west moving Aegean crust more rapidly westward. Abundant evidence supports slab rollback at different velocities along the subduction zone. In Pliocene time, the North Anatolian fault crossed the Hellenides in a complex transtensional zone and a diffuse zone of left-lateral shear crossed western Turkey at present isolating a relatively undeforming Aegean plate. Major tectonic questions include: What is the geometry and fate of subducted slabs?, How much crust is accreted during subduction of thick and

  18. 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

  19. METIERS IN SMALL SCALE FISHERIES IN N.E. AEGEAN

    OpenAIRE

    KAVADAS Stefanos; Petrakis, George; SIAPATIS Apostolis; BARBAS Thomas; DAMALAS DIMITRIOS; ADAMIDOU A.; MAINA I.; KORNARAKI L.

    2012-01-01

    For the numerous métiers of the small scale fisheries in the North-Eastern Aegean sea (Lesvos and Limnos isl.), herein we present the catch composition per métier, the fishing effort and the estimation of total production. Daily logbooks were distributed to 20 professional coastal fishermen to record for a one year period their fishing activity. In total, 68 type of fisheries were reported, grouped in 20 different métiers...

  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. 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.

  2. 210Po activity concentrations in mussels at Aegean Turkish Coast

    International Nuclear Information System (INIS)

    In Turkey mussels (Mytilus galloprovincialis) are consumed in relatively large quantities. Therefore, analyses of mussel samples from different sampling sites in Aegean Sea were performed in order to evaluate the ingestion of 210Po and 210Pb by the Turkey population. Polonium analyses were performed with a complete dissolution of the sample in mineral acids. Polonium isotopes were plated onto a copper discs in 0.5 M HCl solution in the presence of ascorbic acid using a technique modified from Flynn (1968). The alpha activity measurements of polonium isotopes plated on copper discs were performed with ZnS(Ag) detector. The highest concentrations was found in Karaburun mussels as 254 Bq.kg-1 and the lowest one was at Inciralti as 18 Bq.kg-1. Based on these 210Po activity concentrations, annual dose equivalent rates delivered to biological tissues in mussels would vary widely, from 136 to 10 mSv.y-1. It is concluded that in mussels living in the Aegean Sea a wide range of internal radiation dose exists and it is essentially sustained by 210Po food-chain transfer. (author)

  3. Effects of persistent organic pollutants on the thyroid function of the European sea bass (Dicentrarchus labrax) from the Aegean sea, is it an endocrine disruption?

    OpenAIRE

    Schnitzler, J.G; Koutrakis, E.T.; Siebert, U; Thomé, J.-P.; Das, K.

    2008-01-01

    We evaluated the alterations of organochlorinated compounds such as polychlorobiphenyls (PCB), dichloro-diphenyl-dichloroethylene (DDE) and dichloro-diphenyl-trichloroethane (DDT) on the thyroid in wild and cultured sea bass (Dicentrarchus labrax) at environmental concentrations. These compounds influence the endocrine system of many fish species and are qualified as endocrine disruptors. The thyroid seems to be a target organ. Two alteration endpoints: the thyroid histology and the muscular ...

  4. Babylonian confusion of gudgeons in the west Aegean drainages inferred by the mitochondrial DNA analyses

    OpenAIRE

    Radek Sanda; Jasna Vukic; Michal Nowak; Jan Mendel; Tihomir Stefanov; Stamatis Zogaris

    2015-01-01

    Gudgeons (Gobio and Romanogobio, Cypriniformes) are taxonomically very complicated group of primary freshwater fishes. The region of the west Aegean Sea rivers is inhabited by three species according to Kottelat and Freyhof (2007): Gobio feraensis endemic to the Pinios River basin; Gobio balcanicus inhabiting all remaining drainages, from the Aliakmon up to the Marica drainage; and Romanogobio elimeus occurring from the Pinios to the Vardar basin. Recent analysis of barcoding gene cytochrome ...

  5. Evolution of freshwater crab diversity in the Aegean region (Crustacea: Brachyura: Potamidae).

    Science.gov (United States)

    Jesse, Ruth; Grudinski, Melanie; Klaus, Sebastian; Streit, Bruno; Pfenninger, Markus

    2011-04-01

    The aim of this study was to estimate the influence of the palaeogeographic and climatic history of the Aegean region on the diversity of freshwater crabs of the genus Potamon and to test whether this area served as source or reservoir in species diversity. Necessary species delimitation was accomplished by phylogenetic analyses of the mitochondrial markers COX1 and ND1, partial 16S rRNA gene and the tRNALeu gene. We found 14 genetic lineages of which nine could be assigned to previously recognised species. Temporal estimates of the splitting pattern in the phylogeny of Potamon indicated that a combination of geological and climatic events influenced their diversification. Within Potamon, the lineages separated into a western group and an eastern group. This first split in the genus occurred approximately 8.3-5.5 Mya, thus possibly correlated with the Messinian salinity crisis. A likelihood approach to geographic range evolution suggested for most species, occurring in the Aegean area, an origin in the Middle East. Moreover, there were no insular endemics in the central Aegean archipelago, therefore low sea-levels during the Pleistocene glacial periods possibly enabled dispersal to these islands, but subsequent rise in sea-level did not cause speciation. Nevertheless, the diversification of most lineages occurred during the Pleistocene epoch thus coinciding with Quaternary fluctuations of the climate. PMID:21216297

  6. Babylonian confusion of gudgeons in the west Aegean drainages inferred by the mitochondrial DNA analyses

    Directory of Open Access Journals (Sweden)

    Radek Sanda

    2015-11-01

    We have analysed control region (mitochondrial non coding DNA of gudgeon populations from all larger river drainages from the west Aegean region (Pinios to Marica basins. Included were also several populations from surrounding areas of the Danube River drainage and from the Black Sea rivers. The results are not at all congruent with the proposed taxonomy. MtDNA haplotypes of Romonagobio banarescui were found not only in the Vardar, but also in the lower Aliakmon River. Haplotypes of Romanogibo elimeus were found in the Pinios, upper Aliakmon and Loudias rivers. Situation of genus Gobio is completely confusing; there is no geographic structure in the distribution of haplotypes. Many different haplogroups are shared in some basins, especially in the drainages of the Struma, Mesta and Marica rivers. This indicates complicated evolutionary history of gudgeons in the region, probably having several historical refugia, and with multiple recent contacts of lineages. Our data indicate a contact between the Danubian, Black Sea and Aegean rivers. The taxonomic status of most of the populations of Gobio from the west Aegean area remains unclear.

  7. A tomography image of the Aegean region (Greece derived from inversion of macroseismic intensity data

    Directory of Open Access Journals (Sweden)

    D. Papanastassiou

    1997-06-01

    Full Text Available The three-dimensional attenuation structure beneath the Aegean sea and the surrounding regions was determined by inversion of seismic intensity data. A large number of seismic intensity data have been accumulated in a uniform scale in the Aegean region, where the seismic activity is much higher than that of the other Mediterranean regions. Nearly 11000 seismic intensity data from 47 earthquakes that have occurred in these regions were used to determine the seismic attenuation structure. The resulting structure reveals a remarkable contrast of attenuation. In the top layer (depth 0-20 km, low Q is dominant in the central Aegean sea, while high Q is dominant in the surrounding land areas, except for Southwestern Turkey. The low-Q regions correspond to areas of Neogene-Quaternary grabens where the high seismicity of shallow earthquakes appears. In the lower layer (20-40 km low-Q areas are located in the southeastern part of the Hellenic arc. Some low-Q spots corresponding to the distribution of volcanoes exist along the volcanic arc. The low-Q spots might correspond to diapirs causing subduction volcanism.

  8. 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; Badger, Jake; Badger, Merete; Foussekis, Dimitri; Nielsen, Morten; Topouzelis, Konstantinos

    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 to...

  9. 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

    2016-03-01

    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 ± 1 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 paleoclimatic evidence derived from the 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

  10. 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

  11. Assessment of impact of geochemical and environmental properties on the meiofauna (benthic foraminifer, ostracod, mollusc) assemblages: A case study in The Late Quaternary Sediments In The Gulf Of Izmir (Eastern Aegean Sea)

    Science.gov (United States)

    Yümün, Zeki Ü.

    2016-04-01

    The drilling samples collected from varying depths at 1.00-13.00 m at four different localities of Karsiyaka, Bayrakli, Inciralti and Urla (Çesmealti) in the Gulf of Izmir were studied for their geochemical, sedimantological and micropaleontological properties. The purpose of this study is to describe the meiofauna of the sediments, to determine the pollution history of the gulf and to show the effect of the pollution on the foraminifera and ostracoda. Examination of the loose sediments reveals that the gulf has been affected by the sea for a long time, and it had a rich microfaunal assemblages. Both foraminiferal tests and ostracod carapaces have coloring, and morphological abnormalities have been determined in foraminiferal tests. Peneroplis pertusus (Forskal) and P. planatus (Fichtel and Moll) have blue and black colored tests, while morphological abnormalities were observed on the tests of Ammonia compacta Hofker, Elphidium complanatum (d'Orbigny), E. crispum (Linné), E. macellum (Fichtel and Moll). The ostracod carapaces are generally gray-black colored. Heavy metal (Cr, Mn, Zn, Co, Ni, Cu) analyses have been carried out on the sediments of the Gulf of Izmir. Heavy metal concentrations are high in Bayrakli, and low in Urla (Çesmealti). Cr, Mn and Zn values are the highest in Bayrakli, whereas Co, Ni and Cu values are the highest in Inciralti. Scanning Electron Microscope (SEM) analyses were performed and no heavy metal was detected on the white and colored ostracod carapaces. When the white and colored ostracod carapaces are compared, the coloured ostracode carapace has higher Mg content, and also includes Fe, Al, N, Cl and K. Based on the results obtained, it is observed that the Bayrakli region have been more affected by the pollution than Urla (Çesmealti).

  12. 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.

  13. Occurrence of the Alien Species Aspidosiphon (Aspidosiphon) elegans (Sipuncula) on the Levantine and Aegean Coasts of Turkey

    OpenAIRE

    AÇIK, Şermin

    2008-01-01

    A total of 37 specimens of Aspidosiphon (Aspidosiphon) elegans were collected at 5 stations located along the Levantine coast of Turkey and at 1 station located near Foça (Aegean Sea). This species inhabited calcareous rocks, the mussel Branchidontes pharaonis, and the alga Corallina mediterranea between 0 and 3 m depths. The population density of this species in the area was found to be 25 ind. M-2. As Aspidosiphon (A.) elegans is a bio-eroder species, its high population density may cause s...

  14. 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

  15. Determination of Upper Mantle Heterogeneity Beneath Aegean-Anatolian Region from Travel Time Tomography

    Science.gov (United States)

    Aksari, D.; Simbaad Team

    2011-12-01

    Movement and the deformation of the continental lithosphere are not clear completely. In the first end-member model, the lithosphere consists of essentially rigid blocks (with most of the strength located in the upper crust) that float on the asthenosphere, are separated by lithospheric faults, and move because of forces applied to their edges. The second model holds that the lithosphere (including the upper mantle) deforms as a continuum, and that the upper crust moves in response to tractions applied to its base. Most elements of the debate are related to deformation at the surface or within the shallow crust (fault kinematics, geodetic displacements, or earthquake mechanisms). The Aegean Sea, the surrounding Greek coasts and the western Turkey, along with the Hellenic Arc, are the most active seismic areas of the Mediterranean Basin and of the whole Alpine-Himalayan chain. The catalogues of seismicity are certainly incomplete for low magnitude events (M30 km). This happens along the Hellenic Arc and in the Antalya Gulf (southern Turkey). In the whole area, the frequency of events with magnitude greater than 4, is evident, but there are many events with lower magnitudes. Teleseismic tomography is a powerful tool used to obtain about the deep velocity perturbations in the Earth, using travel times recorded by a regional network from distant sources (usually at distances of more than 20°). This method has been developed since the seventies [1] and has been successfully used for the investigation of different regions (e.g. [2-3]). The images of seismic anomalies are then used for the estimation of the distribution of temperature, density and other parameters [4], which then can be used for geodynamic modeling, gravity inversion [2,5] and other applications. We expect to obtain a 3D image of the velocity structure of the Hellenic Arc Zone beneath Greece and Aegean region to a depth of about 300 km. The results might provide better constrains on the evolution of the

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Tectonic implications of spatial variation of b-values and heat flow in the Aegean region

    Science.gov (United States)

    Kalyoncuoglu, U. Yalcin; Elitok, Ömer; Dolmaz, M. Nuri

    2013-03-01

    The Aegean region is tectonically a complex area characterized mainly by the subduction of African oceanic lithosphere beneath the Aegean continental lithosphere including extensional subbasins and mantle driven block rotations. In this study, spatial distribution of earthquakes, b-value distribution, and heat flow data have been analyzed to reveal the deep structural features of the Aegean region. b-value distributions show two low NE-SW and NW-SE trending b-anomaly zones in the western and eastern side of the Crete, implying slab tear within the Aegean slab. Earthquake foci distribution indicates that the Aegean slab steepens in the eastern side of the Crete, compared to its western side. Earthquake foci reach maximum depth of 180 km along the Cycladic arc axis, suggesting northward subducted slab geometry. The low seismic activities and high b-value anomalies within Aegean basin, except North Aegean Trough, can be compared to higher heat flow. We concluded that collision-induced westward mantle flow beneath Turkey followed by hard collision between Arabian-Eurasian continental plates played a major role in the evolution of clockwise rotational retreat of the Aegean slab and slab steepening to the east of the Crete.

  18. Crust Structure Data of Seas Surrounding Turkey

    International Nuclear Information System (INIS)

    Black Sea, Aegean, Mediterranean and Marmara Sea, which surround the Turkey, have not been examined with respect to the Geological, Geophysical and other natural sciences sufficiently. In fact, it is not attach importance the Turkish seas adequately and abandoned with respect to the scientific researches. The most important reason of this situation is the lack of the education of the Marine Sciences in the Turkish Universities. In this study, it is tried to construct a crustal structure data base of the surrounding seas of the Turkey by collecting crustal structure data sets done by different authors in different times so far. The data acquired in the base are collected from different data base sources by dragging. The Moho depth in the eastern and western basin of the Black sea is 22 km and 19 km, respectively. In the Marmara Sea the Moho depth is 24 km. The moho value in the southern Aegean is 20 km, in the northern Aegean the moho depth is 30 km. on the other hand, the moho depth value in the eastern and western basin of the Mediterranean Sea are 15-20 km and 25-30 km, respectively

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

    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.

  1. Velocity and deformation fields in the North Aegean domain, Greece, and implications for fault kinematics, derived from GPS data 1993-2009

    Science.gov (United States)

    Müller, M. D.; Geiger, A.; Kahle, H.-G.; Veis, G.; Billiris, H.; Paradissis, D.; Felekis, S.

    2013-06-01

    GPS rates based on data of an extended continuous and campaign-type GPS network in the North Aegean domain are presented. The data processed for the time period 1993-2009 is used to analyze the complex kinematic and deformation fields in the North Aegean Sea and adjacent regions. The presence of slowly deforming areas is investigated. Southern Bulgaria, eastern Macedonia and Thrace move uniformly southward relative to Eurasia (1.5-3.5 mm/yr). Western Macedonia, Epirus, Thessaly and Central Greece rotate rather coherently clockwise. The region comprising the islands of Limnos, Agios Efstratios and Alonnisos moves like a counterclockwise rotating slowly deforming block. The new GPS rates allow a quantification of the spatial change of strike-slip motion and locking depth along the North Aegean trough. Dextral strike-slip motion diminishes from east toward west amounting to 21.2 mm/yr along the Saros basin and 12.5 mm/yr south of the Chalkidiki peninsula. Less than 5 mm/yr (50 nstrain/yr shear strain rate) is transferred from the Sporades islands/Pelion toward Northern Evia. The locking depth is shallow for the Ganos fault and the western Saros basin (5.6-8.9 km). It is deeper between the Sporades islands and Pelion (~ 17.7 km) corresponding to a more diffuse shear zone. An elementary finite element model is applied to derive slip rates of the three main ENE-WSW to NE-SW trending dextral strike-slip faults in the North Aegean. Large-scale N-S to NNE-SSW extension in the North Aegean domain is analyzed by employing finite element and GPS based strain rate analyses. Pronounced extension (> 100 nstrain) is associated with known tectonic structures (e.g., Mygdonian graben, northern Gulf of Evia). In offshore areas such as the Sporades basin the correspondence between GPS derived extension rates and active fault structures is not entirely evident. However, important constraints are provided for seismotectonic interpretations.

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

    Directory of Open Access Journals (Sweden)

    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

  3. Early farmers from across Europe directly descended from Neolithic Aegeans.

    Science.gov (United States)

    Hofmanová, Zuzana; Kreutzer, Susanne; Hellenthal, Garrett; Sell, Christian; Diekmann, Yoan; Díez-Del-Molino, David; van Dorp, Lucy; López, Saioa; Kousathanas, Athanasios; Link, Vivian; Kirsanow, Karola; Cassidy, Lara M; Martiniano, Rui; Strobel, Melanie; Scheu, Amelie; Kotsakis, Kostas; Halstead, Paul; Triantaphyllou, Sevi; Kyparissi-Apostolika, Nina; Urem-Kotsou, Dushka; Ziota, Christina; Adaktylou, Fotini; Gopalan, Shyamalika; Bobo, Dean M; Winkelbach, Laura; Blöcher, Jens; Unterländer, Martina; Leuenberger, Christoph; Çilingiroğlu, Çiler; Horejs, Barbara; Gerritsen, Fokke; Shennan, Stephen J; Bradley, Daniel G; Currat, Mathias; Veeramah, Krishna R; Wegmann, Daniel; Thomas, Mark G; Papageorgopoulou, Christina; Burger, Joachim

    2016-06-21

    Farming and sedentism first appeared in southwestern Asia during the early Holocene and later spread to neighboring regions, including Europe, along multiple dispersal routes. Conspicuous uncertainties remain about the relative roles of migration, cultural diffusion, and admixture with local foragers in the early Neolithization of Europe. Here we present paleogenomic data for five Neolithic individuals from northern Greece and northwestern Turkey spanning the time and region of the earliest spread of farming into Europe. We use a novel approach to recalibrate raw reads and call genotypes from ancient DNA and observe striking genetic similarity both among Aegean early farmers and with those from across Europe. Our study demonstrates a direct genetic link between Mediterranean and Central European early farmers and those of Greece and Anatolia, extending the European Neolithic migratory chain all the way back to southwestern Asia. PMID:27274049

  4. Application of multivariate techniques to analytical data on Aegean ceramics

    International Nuclear Information System (INIS)

    The general problems of data collection and handling for multivariate elemental analyses of ancient pottery are considered including such specific questions as the level of analytical precision required, the number and type of elements to be determined and the need for comprehensive multivariate statistical analysis of the collected data in contrast to element by element statistical analysis. The multivariate statistical procedures of clustering in a multidimensional space and determination of the numerical probabilities of specimens belonging to a group through calculation of the Mahalanobis distances for these specimens in multicomponent space are described together with supporting univariate statistical procedures used at Brookhaven. The application of these techniques to the data on Late Bronze Age Aegean pottery (largely previously analysed at Oxford and Brookhaven with some new specimens considered) have resulted in meaningful subdivisions of previously established groups. (author)

  5. Segmentation of Aegean Fishing Fleet and Spatial Distribution of Fishing Capacity

    OpenAIRE

    Ilke Kosar Danisman

    2013-01-01

    The data on fishing fleet play an important role in fisheries management. It is an effective method that collection of reliable and regular data on fleet, and these data into information that is needed in terms of fleet management. In this study, it is demonstrated that the segmentation of the Aegean fishing fleet and fishing port based spatial distribution of fishing capacities concerning each fleet segment at the Aegean coast to improve fisheries management.

  6. Statistical study of epicentre alignment in the broader Aegean area

    Directory of Open Access Journals (Sweden)

    E. Papadirnitriou

    1994-06-01

    Full Text Available Accurate data concerning shallow (h = 60 km earthquakes (Ms =4.5 that occurred in the broader Aegean area are used to point out the presence of linear seismogenic structures (seismolineaments. The earthquake data were analyzed by the use of a specific algorithm, and the directions of the best alignment of epicentres were found. The algorithm is based on statistical criteria applied within a circular area with the aim of searching for the best direction of alignment; this is then tested, to discriminate whether or not the pattern could stem from a random distribution of epicentres, or whether it is effectively the result of a linear seismic structure; the procedure is repeated to cover the whole area examined. The resulting lineaments can be regarded as individual tectonic units, as they usually coincide with known active faults or fault systems. An interpretation is given of the spatio-temporal evolution of the seismicity along the lineaments in terms of the asperity model.

  7. 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

    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.

  8. Chronology for the Aegean Late Bronze Age 1700-1400 B.C.

    Science.gov (United States)

    Manning, Sturt W; Ramsey, Christopher Bronk; Kutschera, Walter; Higham, Thomas; Kromer, Bernd; Steier, Peter; Wild, Eva M

    2006-04-28

    Radiocarbon (carbon-14) data from the Aegean Bronze Age 1700-1400 B.C. show that the Santorini (Thera) eruption must have occurred in the late 17th century B.C. By using carbon-14 dates from the surrounding region, cultural phases, and Bayesian statistical analysis, we established a chronology for the initial Aegean Late Bronze Age cultural phases (Late Minoan IA, IB, and II). This chronology contrasts with conventional archaeological dates and cultural synthesis: stretching out the Late Minoan IA, IB, and II phases by approximately 100 years and requiring reassessment of standard interpretations of associations between the Egyptian and Near Eastern historical dates and phases and those in the Aegean and Cyprus in the mid-second millennium B.C. PMID:16645092

  9. Cluster analysis of indermediate deep events in the southeastern Aegean

    Science.gov (United States)

    Ruscic, Marija; Becker, Dirk; Brüstle, Andrea; Meier, Thomas

    2015-04-01

    The Hellenic subduction zone (HSZ) is the seismically most active region in Europe where the oceanic African litosphere is subducting beneath the continental Aegean plate. Although there are numerous studies of seismicity in the HSZ, very few focus on the eastern HSZ and the Wadati-Benioff-Zone of the subducting slab in that part of the HSZ. In order to gain a better understanding of the geodynamic processes in the region a dense local seismic network is required. From September 2005 to March 2007, the temporary seismic network EGELADOS has been deployed covering the entire HSZ. It consisted of 56 onshore and 23 offshore broadband stations with addition of 19 stations from GEOFON, NOA and MedNet to complete the network. Here, we focus on a cluster of intermediate deep seismicity recorded by the EGELADOS network within the subducting African slab in the region of the Nysiros volcano. The cluster consists of 159 events at 80 to 190 km depth with magnitudes between 0.2 and 4.1 that were located using nonlinear location tool NonLinLoc. A double-difference earthquake relocation using the HypoDD software is performed with both manual readings of onset times and differential traveltimes obtained by separate cross correlation of P- and S-waveforms. Single event locations are compared to relative relocations. The event hypocenters fall into a thin zone close to the top of the slab defining its geometry with an accuracy of a few kilometers. At intermediate depth the slab is dipping towards the NW at an angle of about 30°. That means it is dipping steeper than in the western part of the HSZ. The edge of the slab is clearly defined by an abrupt disappearance of intermediate depths seismicity towards the NE. It is found approximately beneath the Turkish coastline. Furthermore, results of a cluster analysis based on the cross correlation of three-component waveforms are shown as a function of frequency and the spatio-temporal migration of the seismic activity is analysed.

  10. Lifelong Learning and Vocational Training Programmes in Northern Aegean (Greece): Weaknesses, Possibilities and Prospects

    Science.gov (United States)

    Giavrimis, Panagiotis; Papanis, Efstratios; Mitrellou, Sotiria; Nikolarea, Ekaterini

    2009-01-01

    This study presents, discusses and assesses the findings of a research into lifelong learning through Vocational Training Centres (VTCs) in the region of Northern Aegean, Greece. In the first part, the paper introduces its readers to the theoretical framework of lifelong education, whereas in the second part it makes a brief historical overview of…

  11. 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

  12. Anelastic attenuation structure of the southern Aegean subduction area

    Science.gov (United States)

    Ventouzi, Chrisanthi; Papazachos, Constantinos; Papaioannou, Christos; Hatzidimitriou, Panagiotis

    2014-05-01

    The study of the anelastic attenuation structure plays a very important role for seismic wave propagation and provides not only valuable constraints for the Earth's interior (temperature, relative viscosity, slab dehydration and melt transport) but also significant information for the simulation of strong ground motions. In order to investigate the attenuation structure of the broader Southern Aegean subduction area, acceleration spectra of intermediate depth earthquakes produced from data provided by two local networks which operated in the area were used. More specifically, we employed data from approximately 400 intermediate-depth earthquakes, as these were recorded from the EGELADOS seismic monitoring project which consisted of 65 land stations and 24 OBS recorders and operated during 2005-2007, as well as data from the earlier installed CYCNET local network, which operated during 2002-2005. A frequency-independent path attenuation operator t* was computed for both P and S arrivals for each waveform, using amplitude spectra generated by the recorded data of the aforementioned networks. Initially, estimated P and S traveltimes were examined and modeled as a function of epicentral distance for different groups of focal depths, using data from the CYCNET network in order to obtain the expected arrival information when original arrival times were not available. Two approaches to assess the spectral-decay were adopted for t* determination. Initially, an automated approach was used, where t* was automatically calculated from the slope of the acceleration spectrum, assuming an ω2 source model for frequencies above the corner frequency, fc. Estimation of t* was performed in the frequency band of 0.2 to 25 Hz, using only spectra with a signal-to-noise ratio larger than 3 for a frequency range of at least 4Hz for P-waves and 1Hz for S-waves, respectively. In the second approach, the selection of the linearly-decaying part of the spectra where t* was calculated, was

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

    OpenAIRE

    Ahmet Cihan; Ömer Demir; Ali Şahin; Fatih Zeren; Deniz Bolat; Burak Özçift; Abdulkadir Pektaş; Ertan Can; Bilal Gümüş; Tahir Turan; Ahmet Bölükbaşı; Haluk Erol; Ahmet Adil Esen

    2014-01-01

    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...

  14. Population development of the invader ctenophore Mnemiopsis leidyi, in the Black Sea and in other seas of the Mediterranean basin

    OpenAIRE

    Shiganova, T.A.; Mirzoyan, Z.A.; Studenikina, E.A.; Volovik, S.P.; Siokou-Frangou, I.; S. ZERVOUDAKI; Christou, E. D.; Skirta, A.Y.; Dumont, H.J.

    2001-01-01

    In the last two decades of the twentieth century, the ctenophore Mnemiopsis leidyi (A. Agassiz) has invaded the Black, Azov, Marmara and Aegean Seas, and, recently, the Caspian Sea. Here, we compare its spatial and temporal distribution, seasonal dynamics and the time and duration of reproduction. We also discuss factors that control its abundance throughout its invasive range and its effect on ecosystems. Observations are based on the long-term field data collected by three research institut...

  15. 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.

    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...

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

    OpenAIRE

    Maria Corsini-Foka

    2015-01-01

    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...

  17. Benthic foraminiferal response to heavy metal pollution in Izmir Bay (eastern Aegean Sea)

    International Nuclear Information System (INIS)

    Benthic foraminifera are interestingly used as environmental bio-indicators, especially in polluted environments where their sensitivity to pollutants may be expressed by a modification of the assemblages. Sixteen sediment samples were collected in November 2002 from surficial sediments of Izmir Bay for the study of foraminiferal assemblages. Izmir Bay is located in Western Turkey and surrounded by a densely populated community. Foraminifera (class Foraminifera, phylum Granuloreticulata) are among the more abundant protozoa in marine and brackish water habitats. They are unicellular protista that construct shells of one and many chambers. Studies of pollution effects on benthic foraminifera were initiated by Resig (1960) and Watkins (1961). The studies have often focused on areas exposed to direct pollution sources such as industrial, agricultural wastes. Some studies also take into account thermal and various kinds of chemical pollution and heavy metal pollution. In our research, we identified 28 foraminifera species. A total of 16 sediment samples used for this study come from selected stations at Izmir Bay. Heavy metals and chemicals are unlikely to favor any particular species of benthic foraminifera. In practice, however, it is often difficult to separate effects caused by heavy metals from those caused by organic material because most polluted areas are subjected to some kind of organic enrichments. Of the major environmental components (water, sediment, flora and fauna), sediments have been thoroughly analyzed to study the occurrence and distribution of metals. They present the clearest indication of metal input and accumulation in aquatic environments. Izmir Bay has been contaminated by numerous heavy metals, but geochemical analyses have shown that metals are significant pollutants in the inner part of the bay. Correlation analysis shows that there is a significant correlation between foraminifera species and heavy metals. Amphycoryna scalaris has significant correlation with Cr, Cu, Ni, Mn. The most of the foraminifera species have significant correlation with Cr (Ammonia tepida, Amphycoryna scalaris, Bulimina marginata, Noniella turgida). Factor analysis separated the species according to their relationships with the toxic heavy metals and non-toxic heavy metals. The cumulative values are 77.29%. We can conclude that there is also a statistically significant relationships between toxic heavy metals and foraminifera species

  18. Antimicrobial and antioxidant activity of brown algae from the Aegean Sea

    OpenAIRE

    ZELIHA DEMIREL; FERDA F. YILMAZ-KOZ; ULKU N. KARABAY-YAVASOGLU; GUVEN OZDEMIR; ATAKAN SUKATAR

    2009-01-01

    The present study was conducted to evaluate the antioxidant and antimicrobial activity of methanol, dichloromethane and hexane extracts, as well as the essential oils of brown algae (Phaeophyta) Colpomenia sinuosa, Dictyota dichotoma, Dictyota dichotoma var. implexa, Petalonia fascia and Scytosiphon lomentaria. The essential oil of the macroalgae was obtained by steam distillation and analyzed by GC and GC/MS. The antioxidant activity of the algal extracts was determined using the procedures ...

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

    OpenAIRE

    P. K. KARACHLE; K. I. STERGIOU

    2013-01-01

    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 we...

  20. 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

  1. 3d Velocity Tomography of The Kos - Nisyros Volcanic Area - East Aegean Sea

    Science.gov (United States)

    Nikolova, S.; Ilinski, D.; Makris, J.; Chonia, T.; Stavrakakis, J.

    Since June 2000, active and passive seismic observations have been carried out by IfG, GeoPro GmbH, Hamburg and Institute of Geodynamics, Athens within the frame of the project GEOWARN (Geo-Spacial Warning Systems Nisyros Volcano, Greece: An Emergency Case Study of the Volcanic Area of Nisyros) supported by the European Community. In the active experiment 48 recording seismic units were deployed and recorded more than 7000 shots in 3D array. The Nisyros volcano has been identified as an apophytic intrusion of much larger volcanic structure with a caldera of 35 km diameter, extending between the southern coasts of the islands of Kos and Nisyros. To obtain 3-D velocity structure of the area a tomographic inversion was made using 6800 rays which probed the area with a very high ray density. The method applied and the high accuracy of active tomographic data allowed to resolve the high velocity bodies in the caldera. The complex volcanic structure is identified by high velocity rocks in- truding through the upper crust and penetrating the volcanic cone to depth of approx. 1.0 km to 1.8 km below the surface. Particularly high velocity bodies were identified below the islands of Yali and the central caldera of Nisyros. The high velocity bodies at shallow depth were interpreted as high-density cumulates of solidified magma intru- sion in the caldera. These intrusions explain very high temperature of 300C observed in the lower aquifer in the caldera at 1.5 km depth as confirmed by drilling. The vol- canic edifices of Kos, Yali, Nisyros and Strongily are part of a major volcanic caldera nearly 35 km in diameter. This size of the volcanic caldera explains the large volume of ignimbrites erupted 160 000 years ago. By combining geodetic, geophysical, geo- chemical and geological observations it is intended to correlate magma movements and associated changes of physical and chemical parameters of the recent volcanism.

  2. Reproductive biology of the prawn Melicertus kerathurus (Decapoda: Penaeidae) in Thermaikos Gulf (N. Aegean Sea)

    Science.gov (United States)

    Kevrekidis, Kosmas; Thessalou-Legaki, Maria

    2013-03-01

    The reproductive biology including insemination frequency, ovarian maturation, gonadosomatic index (GSI), size at first maturity, and fecundity of Melicertus kerathurus were investigated using monthly samples from Thermaikos Gulf. Insemination was recorded by the presence of a spermatophore in the thelycum, and ovarian development was based on macroscopic ovarian staging (ST1-ST5). Inseminated females were found throughout the year with high percentages recorded from April to July. Although all ovarian stages were represented in mated females, insemination increased with size and ovarian maturation. High percentages of vitellogenic or mature ovarian stages were observed from May to July, while immature and developing ovaries were predominant mainly in winter. Spawned ovaries occurred from May to October. Carapace length at first maturity based on the presence of a spermatophore (CL50sp) was estimated at 39.20 mm, while that based on the presence of vitellogenic and mature ovaries (CL50ov) at 40.70 mm. The seasonal peak in the proportion of mature females (ST4) varied with size. Inseminated females at ST4 and GSI peaked in June-July. GSI varied in relation to insemination status and ovarian stage. In large females (>50 mm CL), the decline in mature ovaries and GSI increment with size indicates a relative reduction in the reproductive output. The number of oocytes ranged from 62,742 to 602,947 (mean ± SD: 268,000 ± 113,000). As the prawns are targeted during the spawning season, mainly by the artisanal fishery, and female size at first maturity is selected by artisanal net size, managerial measures toward artisanal fishery should be implemented.

  3. Turkish pelagic gillnet fishery for swordfish and incidental catches in the Aegean Sea

    OpenAIRE

    Akyol, Okan; Ceyhan, Tevfik; ERDEM, Mustafa

    2012-01-01

    Abstract This study was carried out with 20 representative gill-netters based at the port of Sivrice and Sığacık from June 2008 to August 2010. The average length, gross tonnage (GT), machine power (hp) and number of personnel of the gill-netters were 10.4±0.6 m, 10.5±2.3 GT, 121.4±19.9 hp and 3.4±0.2 persons, respectively. Total length of all observed gillnets was reaching 339 km, ranged from 700 to 6000 m with average 2672 ±93 m. The mean CPUEs for swordfish by number and weight were calcul...

  4. Neogene volcanism and extension in Western Anatolian-Aegean area: A new geodynamic model

    International Nuclear Information System (INIS)

    The widespread Western Anatolian-Aegean Neogene volcanism presents a complex geochemical evolution reflecting the uncommon space-time variability of the geodynamic setting of the region. In the Western Anatolian and Central Aegean, a widespread supra-subduction magmatism, with calc-alkaline to shoshonitic affinity, took place from Early to Middle Miocene; this phase of activity ends with spots of ultra-K lavas and dykes. From Late Miocene onwards scattered alkali basaltic lavas with intraplate affinity were emitted, while calc-alkaline activity occurred in the South Aegean arc. Since Late Oligocene-Early Miocene, the region was, and still is, affected by extensional tectonics generally ascribed to a backarc rift. However the Aegean region should rather be considered as an unconventional backarc since its characteristics rather differ from 'typical' backarcs. In fact, in spite of a long lasting(>40Ma) active NE-directed subduction of Africa, the backarc area still maintains a relatively thick continental crust (>20-25 km). Moreover, the upper Eurasian plate is overriding the lower Africa plate with separate segments, with Greece moving faster, and Turkey moving slower. The differential velocity between Greece and Turkey determines extension in the upper plate, unrelated to the loss of subducted retreating lithosphere, which is the usual setting for the origin of 'classic' backarc settings. The geodynamic framework is supported by the geochemical and isotopic features of the supra-subduction magmas revealing the occurrence of a trapped, drying slab, with progressive decreasing of Fluid Mobile Elements/Fluid Immobile Elements ratios, δ11B and δ7Li, coupled with scarce variations of Sr and Nd isotopes. Moreover, the differential motion between the Greek and Anatolian micro-plates creates tear zones with the formation of slab ruptures or vertical slab windows. The occurrence of such windows is, in fact, outlined by the presence of alkali basalts with intraplate

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

    OpenAIRE

    Kerem Ural; Mehmet Gultekin; Abidin Atasoy; Bulent Ulutas

    2015-01-01

    ABSTRACTObjective. 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 c...

  6. Syn- and post-orogenic exhumation of metamorphic rocks in North Aegean

    Directory of Open Access Journals (Sweden)

    R. Lacassin

    2007-11-01

    Full Text Available The Olympos-Ossa-Pelion (OOP ranges, in NW Aegean, encompass Greece highest summit and are located near the extremity of the North Anatolian Fault (NAF. Structural and thermochronological data gathered in the OOP ranges show that the main exhumation of metamorphic nappes occurred in the Eocene, at ca. 43–39 Ma. This early exhumation, associated with ductile, then brittle-ductile normal faulting with northeastward transport, is coeval with orogenic shortening in the close area. Cooling rates, and likely exhumation, have been low between ~40 Ma and ~20 Ma. 40Ar/39Ar crystallization ages (between 20 and 15 Ma appears related to brittle-ductile normal faulting and likely associated with Neogene Aegean back-arc extension. The dating of a diabase dyke, and the geometry of associated brittle jointing, of onshore and offshore active normal faults suggest a shift in extension direction after 4Ma, possibly in relation with the propagation of the NAF in northern Aegean.

  7. Exhumation of metamorphic rocks in N Aegean: the path from shortening to extension and extrusion

    Directory of Open Access Journals (Sweden)

    R. Lacassin

    2007-01-01

    Full Text Available The Olympos-Ossa-Pelion (OOP ranges, in NW Aegean, encompass Greece highest summit and are located near the extremity of the North Anatolian Fault (NAF. Structural and thermochronological data gathered in the OOP ranges show that the main exhumation of metamorphic nappes occurred in the Eocene, at ca. 43–39 Ma. This early exhumation, associated with ductile, then brittle-ductile normal faulting with northeastward transport, is nearly coeval with orogenic shortening in the close area. Cooling rates, and likely exhumation, have been low between ~40 Ma and ~20 Ma. 40Ar/39Ar crystallization ages (between 20 and 15 Ma appears related to brittle-ductile normal faulting and likely associated with the onset of Aegean back-arc extension. The dating of a diabase dyke, and the geometry of associated brittle jointing, of onshore and offshore active normal faults imply a shift in extension direction after 4 Ma. Such a shift is probably related the propagation of the NAF in northern Aegean known to have occurred around 5 Ma.

  8. Focal Mechanisms at the convergent plate boundary in Southern Aegean, Greece.

    Science.gov (United States)

    Moshou, Alexandra; Papadimitriou, Eleftheria; Drakatos, George; Evangelidis, Christos; Karakostas, Vasilios; Vallianatos, Filippos; Makropoulos, Konstantinos

    2014-05-01

    Greece is characterized by high seismicity, mainly due to the collision between the European and the African lithospheric plates and the dextral strike slip motion along the North Anatolia Fault zone and North Aegean Trough. The subduction of the Eastern Mediterranean oceanic plate along the Hellenic Arc under the Aegean microplate along with the accompanied roll back of the descending slab is considered the main tectonic feature of the region (Papazachos and Comninakis 1971; Makropoulos and Burton 1984; Papazachos et al. 2000a, b). The divergent motion between the Aegean block and mainland Europe is indicated by an extension zone in the northern Aegean, with Crete and Aegean diverging from mainland Europe at a rate of about 3.5 cm yr-1 with Africa moving northward relative to Europe at a rate of about 1 cm yr-1 (Dewey et al., 1989; Papazachos et al., 1998; Mc-Clusky et al., 2000; Reilinger et al., 2006). In this tectonically complicated area diverge types of deformation are manifested, in addition to the dominant subduction processes. Aiming to shed more light in the seismotectonic properties and faulting seismological data from the Hellenic Unified Seismological Network (HUSN) were selected and analyzed for determining focal mechanisms using the method of moment tensor inversion, additional to the ones being available from the routine moment tensor solutions and several publications. Thus, 31 new fault plane solutions for events with magnitude M>4.0, are presented in this study, by using the software of Ammon (Randall et al., 1995). For this scope the data from at least 4 stations were used with an adequate azimuthal coverage and with an epicentral distance not more than 350 km. The preparation of the data includes the deconvolution of instruments response, then the velocity was integrated to displacement and finally the horizontal components were rotated to radial and transverse. Following, the signal was inverted using the reflectivity method of Kennett (1983

  9. Uluslarası Antlaşmalar Işığında Ege Adaları Sorunu///The Aegean Islands Issue under the Light of International Treaties

    OpenAIRE

    Neslihan ALTUNCUOĞLU

    2012-01-01

    This article examines the Aegean Island Issue within the scope of Turkish-Italian and German Relations during World War II. The Aegean Islands Issue has been one of the most commonly discussed regional problems since the first quarter of the 20thcentury. Although the Treaty of Lausanne (1923) introduced a short-term solution to the Aegean Islands Issue Italy and Germany reopened the issue for their own national interests. Because of the strategic significance of the Aegean islands, at the b...

  10. 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. PMID:25113103

  11. Reply to: 'A late Pleistocene clockwise rotation phase of Zakynthos (Greece) and implications for the evolution of the western Aegean Arc'

    NARCIS (Netherlands)

    Duermeijer, C.E.; Langereis, C.G.

    2002-01-01

    During the 80s, a number of seminal papers were published by the Gif-sur-Yvette group of Carlo Laj and co-workers, on the late Neogene palaeomagnetic rotations of the Aegean and, in particular, of the Aegean Arc system. These studies shed new light on the tectonic evolution of the region (e.g. [1,2

  12. 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.

  13. 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).

  14. A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

    Science.gov (United States)

    Vamvakaris, D. A.; Papazachos, C. B.; Papaioannou, Ch. A.; Scordilis, E. M.; Karakaisis, G. F.

    2016-01-01

    In the present work we propose a new seismic zonation model of area type sources for the broader Aegean area, which can be readily used for seismic hazard assessment. The definition of this model is based not only on seismicity information but incorporates all available seismotectonic and neotectonic information for the study area, in an attempt to define zones which show not only a rather homogeneous seismicity release but also exhibit similar active faulting characteristics. For this reason, all available seismological information such as fault plane solutions and the corresponding kinematic axes have been incorporated in the analysis, as well as information about active tectonics, such as seismic and active faults. Moreover, various morphotectonic features (e.g. relief, coastline) were also considered. Finally, a revised seismic catalogue is employed and earthquake epicentres since historical times (550 BC-2008) are employed, in order to define areas of common seismotectonic characteristics, that could constitute a discrete seismic zone. A new revised model of 113 earthquake seismic zones of shallow earthquakes for the broader Aegean area is finally proposed. Using the proposed zonation model, a detailed study is performed for the catalogue completeness for the recent instrumental period.Using the defined completeness information, seismicity parameters (such as G-R values) for the 113 new seismic zones have been calculated, and their spatial distribution was also examined. The spatial variation of the obtained b values shows an excellent correlation with the geotectonic setting in the area, in good agreement with previous studies. Moreover, a quantitative estimation of seismicity is performed in terms of the mean return period, Tm, of large (M ≥ 6.0) earthquakes, as well as the most frequent maximum magnitude, Mt, for a typical time period (T = 50 yr), revealing significant spatial variations of seismicity levels within the study area. The new proposed seismic

  15. 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

  16. 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 ...

  17. 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.

  18. 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.

  19. Present situation and future prospects of electricity generation in Aegean Archipelago islands

    International Nuclear Information System (INIS)

    The Aegean Archipelago is a remote Hellenic area, including several hundreds of scattered islands of various sizes. In these islands more than 600,000 people are living mainly in small remote communities. The main economical activities of the islanders are apart from tourism, seafaring, fishery, agriculture and stock farming. One of the major problems of the area is the insufficient infrastructure, strongly related with the absence of an integrated and cost-effective electrification plan. In this context, the present work is concentrated on analyzing the present situation and demonstrating the future prospects of electricity generation in the Aegean Archipelago islands. For this purpose, one should first investigate the time evolution of the corresponding electricity generation parameters (i.e. annual electricity consumption, peak power demand, capacity factor, specific fuel consumption) for the last 30 years. Subsequently, the corresponding diesel and heavy-oil consumption along with the electricity production cost for every specific autonomous power station of the area are investigated. Special attention is paid in order to estimate the contribution of renewable energy sources (RES) in the energy balance of each island. Finally, an attempt is made to describe in brief the most realistic electricity production solutions available, including the operation of hybrid RES-based power plants in collaboration with appropriate energy storage facilities. Additionally, the idea of connecting the islands of the area with the mainland and interconnecting them is also taken into consideration

  20. 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.

  1. Fault slip source models for the 2014 Mw 6.9 Samothraki-Gökçeada earthquake (North Aegean Trough) combining geodetic and seismological observations

    Science.gov (United States)

    Saltogianni, Vasso; Gianniou, Michail; Taymaz, Tuncay; Yolsal-ćevikbilen, Seda; Stiros, Stathis

    2015-12-01

    The 24 May 2014, Mw 6.9, Samothraki-Gökçeada shallow (depth: 11 km) earthquake along the North Aegean Trough (NAT), at the westward extension of the North Anatolian Fault Zone (NAFZ), is investigated using constraints from seismological and geodetic data. A point source solution based on teleseismic long-period P and SH waveforms suggests an essentially strike-slip faulting mechanism consisting of two subevents, while from a finite fault inversion of broadband data the rupture area and slip history were estimated. Analysis of data from 11 permanent GPS stations indicated significant coseismic horizontal displacement but no significant vertical or postseismic slip. Okada-type inversion of horizontal slip vectors, using the new TOPological INVersion algorithm, allowed precise modeling of the fault rupture both as single and preferably as double strike-slip faulting reaching the surface. Variable slip models were also computed. The independent seismological and geodetic fault rupture models are broadly consistent with each other and with structural and seismological data and indicate reactivation of two adjacent fault segments separated by a bend of the NAT. The 2014 earthquake was associated with remote clusters of low-magnitude aftershocks, produced low accelerations, and filled a gap in seismicity along the NAT in the last 50 years; faulting in the NAT seems not directly related to the sequence of recent faulting farther east, along the NAFZ and the seismic gap in the Marmara Sea near Istanbul.

  2. Temporal patterns of detachment faulting along Cycladic extensional metamorphic domes, Aegean region

    Science.gov (United States)

    Schneider, D. A.; Grasemann, B.; Heizler, M.; Vogel, H.; Iglseder, C.

    2007-12-01

    The Aegean region together with the surrounding mainland areas are known for Miocene to Recent active, notably extensional tectonics that are the result of the retreating Hellenic slab, gravitational collapse of the region and, since the Late Miocene to Early Pliocene, the westward escape of Anatolia relative to Eurasia. Project ACCEL (Aegean Core Complexes along an Extended Lithosphere) has collected an extensive modern structural dataset for the islands of Kea, Kithnos, and Serifos of the western Cyclades. On all three islands, crustal-scale, low-angle frictional-viscous shear zones have been identified and record strikingly consistent SSW-directed extensional kinematics together with a WNE-ESE shortening component. The geology of Kea is dominated by highly-strained, greenschist-facies schists, calc-silicates and marbles; a major, 100's m thick ultramylonite zone defines this northern island as a structural dome. White mica Ar-Ar thermochronometry performed on variably deformed units from different structural levels yield consistent Early Miocene (15-19 Ma) cooling ages across the entire island. Other pervasively deformed shallow crustal regions of the Cyclades (Tinos and Andros; b-type domes of Jolivet et al. 2004) also record similar Early Miocene cooling. Comparable geology and structure is exposed on Serifos although locally deformed under amphibolite-facies conditions and intruded in the south by a Late Miocene granodiorite. A major high strain zone that is present on the island is localized along an earlier (Late Eocene) granitic pluton. White micas from mylonites and gneisses along this shear zone and from rocks in the southern portion of the island yield Late Miocene (8-9 Ma) cooling ages, whereas greenschist-facies units in northern Serifos that are dominated by a different structural record of several phases of folding yield Oligocene (30-34 Ma) mica Ar-Ar cooling ages. Oligocene ages are similarly reported from Evvia and Sifnos, which are noted for

  3. Climate change and biodiversity relations in the eastern Black Sea region

    OpenAIRE

    Tüfekçioğlu, Aydın; Altun, Lokman; Özbayram, A. Kemal

    2008-01-01

    Turkey contains a great variety of natural habitats, ranging from Mediterranean, Aegean, and Black Sea beaches to towering coastal and interior mountains, from deeply incised valleys to expensive steppes, from fertile alluvial plains to arid, rocky hillslopes. The richness in the diversity of habitats translates into richness in the biodiversity in Turkey. But, because of rapid human population growth (about 2.5% per year) and associated intensive or unwise utilization of natural resources an...

  4. Earthquakes Versus Surface Deformation: Qualitative and Quantitative Relationships From The Aegean

    Science.gov (United States)

    Pavlides, S.; Caputo, R.

    Historical seismicity of the Aegean Region has been revised in order to associate major earthquakes to specific seismogenic structures. Only earthquakes associated to normal faulting have been considered. All available historical and seismotectonic data relative to co-seismic surface faulting have been collected in order to evaluate the surface rup- ture length (SRL) and the maximum displacement (MD). In order to perform Seismic Hazard analyses, empirical relationships between these parameters and the magnitude have been inferred and the best fitting regression functions have been calculated. Both co-seismic fault rupture lengths and maximum displacements show a logarithmic re- lationships, but our data from the Aegean Region have systematically lower values than the same parameters world-wide though they are similar to those of the East- ern Mediterranean-Middle East region. The upper envelopes of our diagrams (SRL vs Mw and MD vs Mw) have been also estimated and discussed, because they give useful information of the wort-case scenarios; these curces will be also discussed. Further- more, geological and morphological criteria have been used to recognise the tectonic structures along which historical earthquakes occurred in order to define the geolog- ical fault length (GFL). Accordingly, the SRL/GFL ratio seems to have a bimodal distribution with a major peak about 0.8-1.0, indicating that several earthquakes break through almost the entire geological fault length, and a second peak around 0.5, re- lated to the possible segmentation of these major neotectonic faults. In contrast, no relationships can be depicted between the SRL/GFL ratio and the magnitude of the corresponding events.

  5. Strandings of the beaked whales, Risso’s dolphins, and a minke whale on the Turkish coast of the Eastern Mediterranean Sea

    OpenAIRE

    ÖZTÜRK, AYAKA AMAHA; Dede, Arda M. Tonay and Ayhan

    2011-01-01

    Abstract Stranding information of nine Cuvier‟s beaked whale (Ziphius cavirostris) and one Mesoplodon sp., five Risso‟s dolphin (Grampus griseus), and one minke whale (Balaenoptera acutorostrata) on the Turkish coast of the Aegean and Mediterranean Sea was compiled, based on the published and unpublished data between 1964 and 2011. Mesoplodon sp. and the minke whale were rare, possibly visitors, in the eastern Mediterranean Sea.

  6. First evidence of a distal early Holocene ash layer in Eastern Mediterranean deep-sea sediments derived from the Anatolian volcanic province

    OpenAIRE

    Y. Hamann; Sabine Wulf; O. Ersoy; Ehrmann, W.; E. Aydar; Schmiedl, G.;  ,

    2010-01-01

    A hitherto unknown distal volcanic ash layer has been detected in a sediment core recovered from the southeastern Levantine Sea (Eastern Mediterranean Sea). Radiometric, stratigraphic and sedimentological data show that the tephra, here termed as S1 tephra, was deposited between 8970 and 8690 cal yr BP. The high-silica rhyolitic composition excludes an origin from any known eruptions of the Italian, Aegean or Arabian volcanic provinces but suggests a prevailing Central Anatolian provenance. W...

  7. Grow-Out Of Sea Bream Sparus aurata in Turkey, Particularly in a Land-Based Farm With Recirculation System in Çanakkale: Better Use of Water, Nutrients and Space

    OpenAIRE

    , Erdem Ökte

    2002-01-01

    Gilthead sea bream (Sparus aurata) is being farmed in Turkey mostly in cages in the Aegean coast from Çe?me to Fethiye. There is also a new facility that utilizes land-based re-circulation technology in Çanakkale. Stocking densities, growth, maturation and FCR, water quality, diseases and management are examined in the different types of production techniques.

  8. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Directory of Open Access Journals (Sweden)

    Michael B Toffolo

    Full Text Available The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th century BCE according to the Conventional Aegean Chronology and in the late 12(th century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th century BCE.

  9. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Science.gov (United States)

    Toffolo, Michael B; Fantalkin, Alexander; Lemos, Irene S; Felsch, Rainer C S; Niemeier, Wolf-Dietrich; Sanders, Guy D R; Finkelstein, Israel; Boaretto, Elisabetta

    2013-01-01

    The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th) century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th) century BCE according to the Conventional Aegean Chronology and in the late 12(th) century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th) century BCE. PMID:24386150

  10. Multi-activity and Brand Name Local Products on an Island of the North Aegean, Greece

    Directory of Open Access Journals (Sweden)

    Fotis Chatzitheodoridis

    2006-01-01

    Full Text Available The present work refers to a research that took place on Limnos, an island found in North Aegean, the more northern islander region of Greek Archipelagos. In the frame of the research, the factors that shape and influence the rural growth of the island were studied. Via these factors, the structure of rural occupation, as well as the multi-activity phenomenon is described. Moreover, the forms of rural occupation are combined with the farmer's confidence and opinion concerning the brand name rural products of the island. From the results of this research it becomes clear that the phenomenon of rural multi-activity is particularly intense and is related to other occupations in the tertiary sector. The brand name rural local products are mostly supported by the exclusively and mainly occupied in primary sector people, while the multi-activated young people that are secondarily or auxiliary occupied in agriculture dispute the value of local brand name products and their contribution in the growth of the island.

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

    International Nuclear Information System (INIS)

    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 FR Δ SZ sequences, where FR are recumbent folds, Δ a growth episode of metamorphic minerals, and SZ are extensional shear zones. Microstructures imply that mineral growth in the Δ 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 FR Δ 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 40Ar/39Ar isotopic system

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. New constraints on the geometry of the subducting African plate and the overriding Aegean plate obtained from P receiver functions and seismicity

    Directory of Open Access Journals (Sweden)

    F. Sodoudi

    2013-04-01

    Full Text Available New combined P receiver functions and seismicity data obtained from the EGELADOS network employing 65 stations within the Aegean constrained new information on the geometry of the Hellenic subduction zone. The dense network and large dataset enabled us to accurately estimate the Moho of the continental Aegean plate across the whole area. Presence of a negative contrast at the Moho boundary indicating the serpentinized mantle wedge above the subducting African plate was clearly seen along the entire forearc. Furthermore, low seismicity was observed within the serpentinized mantle wedge. We found a relatively thick continental crust (30–43 km with a maximum thickness of about 48 km beneath the Peloponnesus Peninsula, whereas a thinner crust of about 27–30 km was observed beneath western Turkey. The crust of the overriding plate is thinning beneath the southern and central Aegean (Moho depth 23–27 km. Moreover, P receiver functions significantly imaged the subducted African Moho as a strong converted phase down to a depth of 180 km. However, the converted Moho phase appears to be weak for the deeper parts of the African plate suggesting reduced dehydration and nearly complete phase transitions of crustal material into denser phases. We show the subducting African crust along 8 profiles covering the whole southern and central Aegean. Seismicity of the western Hellenic subduction zone was taken from the relocated EHB-ISC catalogue, whereas for the eastern Hellenic subduction zone, we used the catalogues of manually picked hypocenter locations of temporary networks within the Aegean. P receiver function profiles significantly revealed in good agreement with the seismicity a low dip angle slab segment down to 200 km depth in the west. Even though, the African slab seems to be steeper in the eastern Aegean and can be followed down to 300 km depth implying lower temperatures and delayed dehydration towards larger depths in the eastern slab segment

  15. Cost-benefit analysis of remote hybrid wind-diesel power stations: Case study Aegean Sea islands

    International Nuclear Information System (INIS)

    More than one third of world population has no direct access to interconnected electrical networks. Hence, the electrification solution usually considered is based on expensive, though often unreliable, stand-alone systems, mainly small diesel-electric generators. Hybrid wind-diesel power systems are among the most interesting and environmental friendly technological alternatives for the electrification of remote consumers, presenting also increased reliability. More precisely, a hybrid wind-diesel installation, based on an appropriate combination of a small diesel-electric generator and a micro-wind converter, offsets the significant capital cost of the wind turbine and the high operational cost of the diesel-electric generator. In this context, the present study concentrates on a detailed energy production cost analysis in order to estimate the optimum configuration of a wind-diesel-battery stand-alone system used to guarantee the energy autonomy of a typical remote consumer. Accordingly, the influence of the governing parameters-such as wind potential, capital cost, oil price, battery price and first installation cost-on the corresponding electricity production cost is investigated using the developed model. Taking into account the results obtained, hybrid wind-diesel systems may be the most cost-effective electrification solution for numerous isolated consumers located in suitable (average wind speed higher than 6.0 m/s) wind potential regions

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Vitamin D status among adults in the Aegean region of Turkey

    Directory of Open Access Journals (Sweden)

    Güçlü Feyzullah

    2010-12-01

    Full Text Available Abstract Background Vitamin D is a lipid-soluble hormone found in certain foods and synthesized from precursors in the skin when exposed to ultraviolet light. Vitamin D plays a critical role in bone metabolism and many cellular and immunological processes and low levels have been associated with several chronic and infectious diseases. Vitamin D status is assessed by measuring the concentration of serum 25-hydroxyvitamin D [25(OHD]. Vitamin D deficiency is reported to be common worldwide, but little has been reported about the vitamin D status of adults in Turkey. In this cross-sectional study, we determined the prevalence of 25(OHD deficiency in adults residing in a city in the Aegean region of Turkey. Methods A survey was conducted on a representative sample of adults over 20 years old in a non-coastal city at the end of the winter season. Of the 209 households selected by random sampling, 8.6% (n = 18 were unoccupied and 21.5% (n = 45 refused to participate. Blood samples were taken and questions about medical history, vitamin supplementation, sunlight exposure, and dietary calcium and vitamin D intake were asked in face-to-face interviews of 391 adults living in the remaining households. Results The mean serum 25(OHD concentration was 16.9±13.09 ng/mL, with 74.9% of the subjects having 25(OHD deficiency ( Conclusion Adults living in an urban, non-coastal setting in Turkey have a high prevalence of vitamin D deficiency.

  18. 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.

  19. Mitochondrial DNA reveals genetic structuring of Pinna nobilis across the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Daria Sanna

    Full Text Available 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.

  20. Seismic properties and mineral crystallographic preferred orientations from EBSD data: Results from a crustal-scale detachment system, Aegean region

    Science.gov (United States)

    Cossette, Élise; Schneider, David; Audet, Pascal; Grasemann, Bernhard; Habler, Gerlinde

    2015-05-01

    The crystallographic preferred orientations (CPOs) were measured on a suite of samples representative of different structural depths along the West Cycladic Detachment System, Greece. Electron backscatter diffraction (EBSD) analyses were conducted on calcitic and mica schists, impure quartzites, and a blueschist, and the average seismic properties of the rocks were calculated with the Voigt-Reuss-Hill average of the single minerals' elastic stiffness tensor. The calcitic and quartzitic rocks have P- and S-wave velocity anisotropies (AVp, AVs) averaging 8.1% and 7.1%, respectively. The anisotropy increases with depth represented by the blueschist, with AVp averaging 20.3% and AVs averaging 14.5%, due to the content of aligned glaucophane and mica, which strongly control the seismic properties of the rocks. Localised anisotropies of very high magnitudes are caused by the presence of mica schists as they possess the strongest anisotropies, with values of ~ 25% for AVp and AVs. The direction of the fast and slow P-wave velocities occurs parallel and perpendicular to the foliation, respectively, for most samples. The fast propagation has the same NE-SW orientation as the lithospheric stretching direction experienced in the Cyclades since the Late Oligocene. The maximum shear wave anisotropy is subhorizontal, similarly concordant with mineral alignment that developed during extension in the Aegean. Radial anisotropy in the Aegean mid-crust is strongly favoured to azimuthal anisotropy by our results.

  1. Stochastic strong ground motion simulations for the intermediate-depth earthquakes of the south Aegean subduction zone

    Science.gov (United States)

    Kkallas, Harris; Papazachos, Konstantinos; Boore, David; Margaris, Vasilis

    2015-04-01

    We have employed the stochastic finite-fault modelling approach of Motazedian and Atkinson (2005), as described by Boore (2009), for the simulation of Fourier spectra of the Intermediate-depth earthquakes of the south Aegean subduction zone. The stochastic finite-fault method is a practical tool for simulating ground motions of future earthquakes which requires region-specific source, path and site characterizations as input model parameters. For this reason we have used data from both acceleration-sensor and broadband velocity-sensor instruments from intermediate-depth earthquakes with magnitude of M 4.5-6.7 that occurred in the south Aegean subduction zone. Source mechanisms for intermediate-depth events of north Aegean subduction zone are either collected from published information or are constrained using the main faulting types from Kkallas et al. (2013). The attenuation parameters for simulations were adopted from Skarladoudis et al. (2013) and are based on regression analysis of a response spectra database. The site amplification functions for each soil class were adopted from Klimis et al., (1999), while the kappa values were constrained from the analysis of the EGELADOS network data from Ventouzi et al., (2013). The investigation of stress-drop values was based on simulations performed with the EXSIM code for several ranges of stress drop values and by comparing the results with the available Fourier spectra of intermediate-depth earthquakes. Significant differences regarding the strong-motion duration, which is determined from Husid plots (Husid, 1969), have been identified between the for-arc and along-arc stations due to the effect of the low-velocity/low-Q mantle wedge on the seismic wave propagation. In order to estimate appropriate values for the duration of P-waves, we have automatically picked P-S durations on the available seismograms. For the S-wave durations we have used the part of the seismograms starting from the S-arrivals and ending at the

  2. Perception of Financial And Payment Terms Risks: The Analysis of Aegean Exporters

    Directory of Open Access Journals (Sweden)

    Erdal Demiralay

    2011-10-01

    Full Text Available In recent years, the volume of international trade has increased enormously due to the effects of globalization and liberalization of trade. However, political and economic changes, changes in consumer demand, market structures, product and market life cycles, domestic and foreign competition and the degree of effects caused by these changes became more and more significant. Such changes force the firms making or intending to make business globally to implement dynamic strategies and action plans. Considering above mentioned points, this study aims to explore the risks perceived by the exporting firms about financial risk and payment terms within the context of international trade. The firms are analyzed depending on various criteria (i.e. export intensity, firm size, sectors, geographical locations, export activity, age of the firms, export experience. The results of the study indicates that risk perceptions of exporter firms operating in the Aegean Region of Turkey vary

  3. The latest aspects of telluric and electromagnetic variations associated with shallow and intermediate depth earthquakes in the South Aegean

    Directory of Open Access Journals (Sweden)

    M. Bakatsakis

    1997-06-01

    Full Text Available Recent observations of telluric and electromagnetic field variations (radioemissions assocuated with shallow and intermediate depth earthquakes in the South Aegean are presented. A telemetric system, installed on Crete Island, which continuously records the telluric and electromagnetic field variations is described. In the field stations of the system we measure both the telluric variations (using an appropriate electric dipole configuration and the horizontal electric component of the electromagnetic field in 3 kHz, 10 hKz, 41 MHz and 53 MHz (using tuned and l/2 antennas respectively. Furthermore, a theoretical model is given on the generation and the form of preseismic telluric variations based on the charge dislocation model.

  4. 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.

  5. Assessing the determinants of local acceptability of wind-farm investment: A choice experiment in the Greek Aegean Islands

    International Nuclear Information System (INIS)

    This paper aims at analysing the factors, which motivate communities to resist the installation of wind farms in their vicinity. To this end, the choice experiment methodology was employed in communities in two Greek Aegean Islands to assess the determinants of preferences towards different wind-farm projects. Unlike other studies, the willingness to accept welfare measure was adopted. The results of our analysis show that the conservation status of the area where the wind farms are to be installed, along with the governance characteristics of the planning procedure are the most important determinants of local community welfare in relation to wind farms. In contrast to other studies, we find that the physical attributes of wind farms appear to be of less relative importance from a local community welfare point of view. Implications for the EU's future energy policy are drawn.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  8. Inferences on the Mesozoic evolution of the North Aegean from the isotopic record of the Chalkidiki block

    Science.gov (United States)

    Kydonakis, Konstantinos; Brun, Jean-Pierre; Poujol, Marc; Monié, Patrick; Chatzitheodoridis, Elias

    2016-07-01

    The Chalkidiki block is a major domain in the North Aegean that, contrary to other domains in the region, largely escaped thermal perturbations during Tertiary extension. As a result, the Chalkidiki block is an ideal candidate to glean information related to the timing of Mesozoic thermal events using appropriate geochronological techniques. We have undertaken a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) study (U-Th-Pb on monazites and U-Pb on zircons) coupled with 40Ar/39Ar dating on nine samples from various structural levels within the thrust system of the Chalkidiki block. The eastern, and structurally lower part of the system revealed a complete isotopic reset of Carboniferous - Early Triassic monazites coeval with partial monazite destruction, REE-mobilisation and formation of apatite-allanite-epidote coronas at ~ 132 Ma, a reaction that is commonly observed in amphibolite-facies rocks. These coronas formed after crystallisation of garnet (i.e., at T > 580 °C) and, in all probability, either close to the peak-temperature conditions (~ 620 °C) on a prograde path or during retrogression between the peak-temperature and the low-temperature boundary of the amphibolite facies. Cooling of these rocks and arrival at mid-crustal levels occurred at 95-100 Ma. By contrast, the western, and structurally uppermost part of the system went through the same event by 120-125 Ma. Further structural considerations with respect to medium-temperature geochronology data imply that syn-metamorphic thrusting must have ceased by early Late Cretaceous. We emphasize that, with the sole exception of the Chalkidiki block, no pre-45 Ma medium-temperature geochronology data are preserved in other North Aegean domains, a feature that is clearly related to the extension-induced thermal perturbation of the region during the Tertiary.

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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.

  11. GREEK TEACHER’S PERCEPTIONS ABOUT “EFFICIENT” AND “NON-EFFICIENT” STUDENTS DEVELOPMENT OF AN ATTRIBUTION QUESTIONNAIRE FOR TEACHERS IN THE NORTH AEGEAN REGION

    OpenAIRE

    Panagiotis GIAVRIMIS; Efstratios PAPANIS

    2009-01-01

    This research is an attempt in investigating the attributions of teachers about cognitive, learning and psychological characteristics of “good” and “bad” students. A written questionnaire consisting of 35 items, which described potential student behaviour, was filled by 377 Primary, Secondary and University teachers from the North Aegean region. From the factor analysis we can observe five factors characterised “good” students: 1) Parent involvement and behaviour (11 items-16,5% of the varian...

  12. Peeking through the trapdoor: Historical biogeography of the Aegean endemic spider Cyrtocarenum Ausserer, 1871 with an estimation of mtDNA substitution rates for Mygalomorphae.

    Science.gov (United States)

    Kornilios, P; Thanou, E; Kapli, P; Parmakelis, A; Chatzaki, M

    2016-05-01

    The Aegean region, located in the Eastern Mediterranean, is an area of rich biodiversity and endemism. Its position, geographical configuration and complex geological history have shaped the diversification history of many animal taxa. Mygalomorph spiders have drawn the attention of researchers, as excellent model systems for phylogeographical investigations. However, phylogeographic studies of spiders in the Aegean region are scarce. In this study, we focused on the phylogeography of the endemic ctenizid trap-door spider Cyrtocarenum Ausserer, 1871. The genus includes two morphologically described species: C. grajum (C.L. Koch, 1836) and C. cunicularium (Olivier, 1811). We sampled 60 specimens from the distributions of both species and analyzed four mitochondrial and two nuclear markers. Cyrtocarenum served as an example to demonstrate the importance of natural history traits in the inference of phylogeographic scenarios. The mtDNA substitution rates inferred for the genus are profoundly higher compared to araneomorph spiders and other arthropods, which seems tightly associated with their biology. We evaluate published mtDNA substitution rates followed in the literature for mygalomorph spiders and discuss potential pitfalls. Following gene tree (maximum likelihood, Bayesian inference) and species tree approaches ((*)BEAST), we reconstructed a time-calibrated phylogeny of the genus. These results, combined with a biogeographical ancestral-area analysis, helped build a biogeographic scenario that describes how the major palaeogeographic and palaeoclimatic events of the Aegean may have affected the distribution of Cyrtocarenum lineages. The diversification of the genus seems to have begun in the Middle Miocene in the present west Aegean area, while major phylogenetic events occurred at the Miocene-Pliocene boundary for C. cunicularium, probably related to the Messinian Salinity Crisis. Our results also demonstrate the clear molecular distinction of the two

  13. Characterization of juvenile pyroclasts from the Kos Plateau Tuff (Aegean Arc): insights into the eruptive dynamics of a large rhyolitic eruption

    OpenAIRE

    Bouvet De Maisonneuve, Caroline; Bachmann, Olivier; Burgisser, Alain

    2009-01-01

    Silicic pumices formed during explosive volcanic eruptions are faithful recorders of the state of the magma in the conduit, close to or at the fragmentation level. We have characterized four types of pumices from the non-welded rhyolitic Kos Plateau Tuff, which erupted 161,000 years ago in the East Aegean Arc, Greece. The dominant type of pumice (>90 vol.%) shows highly elongated tubular vesicles. These tube pumices occur throughout the eruption. Less common pumice types include: (1) “frothy”...

  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

    2016-06-01

    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.

  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

    2016-01-01

    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 (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. PMID:27311383

  16. Random Seas

    DEFF Research Database (Denmark)

    Liu, Z.; Frigaard, Peter

    Sea waves are the most important phenomenon to be considering in the design of coastal and offshore structures.......Sea waves are the most important phenomenon to be considering in the design of coastal and offshore structures....

  17. 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.

  18. 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.

  19. {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.

  20. 137Cs baseline levels in the Mediterranean and Black Sea: A cross-basin survey of the CIESM Mediterranean Mussel Watch programme

    International Nuclear Information System (INIS)

    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 137Cs 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 137Cs levels were found to be very low (usually -1 wet wt) 137Cs 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

  1. Tracing metal pollution sources of plants and soils in Güzelhisar Basin of Aegean Region, Turkey

    Science.gov (United States)

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

    2016-04-01

    The study area Güzelhisar Basin is 6 km far from the city Aliaga, Aegean Region in the west part of Turkey which represents a rather industrialized area having five large iron and steel mills, but also areas of agriculture. A grid system of 2.5 km to the east and 2.5 km to the west of the Güzelhisar Stream was studied. The area was grouped into three main areas as West, Middle, and East region. Every 500 meters soil samples were taken after the rainfall (April-May) in 2014 from the GPS determined points at 0-30 and 30-60 cm depth. Soil reaction of the study area was determined within the range from 5.87 to 6.61. Even though, the West and the Middle regions had weak carbonate concentrations, the East region was poor in carbonates and relatively high electrical conductivity was measured. Topsoil contamination was examined by 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 the increasing distance from the coast with a simultaneous decrease in pH. Moreover, high plant metal concentrations [mg kg‑¹, ± sd] were detected for B [20.7 ± 23.9], Cu [7.99 ± 5.17], Mn (79.3 ± 89.2), Ni (3.50 ± 3.48), and Zn (25.5 ± 20.1). Transfer of the elements from soil to plants increased in the following order: Co < As < Cr < Pb < Mn < Ni < Cu < Zn < Cd << B.

  2. 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.

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

    Science.gov (United States)

    Kaniewski, David; Van Campo, Elise; Van Lerberghe, Karel; Boiy, Tom; Vansteenhuyse, Klaas; Jans, Greta; Nys, Karin; Weiss, Harvey; Morhange, Christophe; Otto, Thierry; Bretschneider, Joachim

    2011-01-01

    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. PMID:21687714

  4. Repeat hydrography in the Mediterranean Sea, data from the Meteor cruise 84/3 in 2011

    Directory of Open Access Journals (Sweden)

    T. Tanhua

    2013-03-01

    Full Text Available Here we report on data from an oceanographic cruise on the German research vessel Meteor covering large parts of the Mediterranean Sea during spring of 2011. The main objectives of this cruise was to conduct measurements of physical, chemical and biological variables on a section across the Mediterranean Sea with the goal of producing a synoptic picture of the distribution of relevant physical and biogeochemical properties, in order to compare those to historic data sets. During the cruise, a comprehensive data set of relevant variables following the guide lines for repeat hydrography outlined by the GO-SHIP group (http://www.go-ship.org/ was collected. The measurements include; salinity and temperature (CTD, an over-determined carbonate system, inorganic nutrients, oxygen, transient tracers (CFC-12, SF6, Helium isotopes and tritium, and carbon isotopes. The cruise sampled all major basins of the Mediterranean Sea following roughly an east-to-west section from the coast of Lebanon to through the Strait of Gibraltar, and to the coast of Portugal. Also a south-to-north section from the Ionian Sea to the Adriatic Sea was carried out. Additionally, sampling in the Aegean, Adriatic and Tyrrhenian Seas were carried out. The sections roughly followed lines and positions that have been sampled previously during other programs, thus providing the opportunity for comparative investigations of the temporal development of various parameters.

  5. Eastern Mediterranean geodynamics revised: a new Aegean extension realm in space, time and direction identified in the western Cyclades

    Science.gov (United States)

    Grasemann, B.; Edwards, M.; Schneider, D.; Iglseder, C.; Zámolyi, A.; Rambousek, C.; Mueller, M.; Voit, K.; Thoeni, M.; Kloetzli, U.; Exner, U.

    2006-12-01

    The Eastern Mediterranean is renowned for its striking geodynamic features; strong seismicity with distinctive spatial and subsurface distributions, lucid slab tomography and accelerated slab retreat bourne out by some of the globally greatest angular velocities for continental crust displacement. The key questions of historical persistence of or precursor(s) to this setting are addressed by the early blueschist genesis and exhumation during collision and subsequent later-orogenic extension. The extension, in particular, is critical to the geodynamic models; the magnitude, distribution, kinematics, thermal structure and overall timetable are key variables. When and how did extension migrate /switch to the Cretan region and the presently active Gulf of Corinth? Most constraints have hitherto come from the central and western Cyclades (e.g. Naxos, Mykonos, Tinos, Paros) where an overall N-NE directed kinematics of Mid-Late Miocene extension (including any attendant melting) are documented through structural analyses, crystallisation and/or cooling geochronology and geobarometry. The eastern Cyclades meanwhile have lacked such comprehensive study. Project ACCEL (Aegean Core Complexes along an Extended Lithosphere) has obtained equivalent datasets for the eastern Cyclades that identify a realm of opposite kinematic sense (S-SW directed) crustal extension coeval with anatexis and multiple crustal failure that are apparently protracted since Eocene to Late Miocene; much earlier than for the central and western Cyclades. On Serifos island, P/T conditions (from petrology and deformation mechanisms), zircon U-Pb TIMS crystallisation ages, Rb-Sr cooling ages and structural surveying reveal that a major granodiorite intrusion syn- to post-dates a top-to-SSW, mid-upper crustal, mylonitic lithospheric-scale extensional detachment. This entire package further cross-cuts an earlier top-to-SSW, lower-mid crustal, high strain zone that mylonitises an S-type granite whose zircons

  6. Seasonal and vertical variations of phytoplankton composition in Marine Park of Gökçeada Island in the North Aegean Sea

    OpenAIRE

    Güreşen, Aysu; Turan, Yelda Aktan

    2014-01-01

    Abstract This study was conducted to understand the seasonal and vertical variations in the composition and abundance of phytoplankton assemblages in the Marine Park of Gökçeada Island and to evaluate the relations of phytoplankton community structure with the environmental parameters. Water samples were taken from the water column at surface water, 10 m, 20 m and 28 m depths in Yıldız Bay seasonally between May 2009 and January 2010. A total of 28 species belonging to Bacillariophyceae (61%)...

  7. Phytoplankton composition and abundance in the coastal waters of the Datça and Bozburun Peninsulas, south-eastern Aegean Sea (Turkey

    Directory of Open Access Journals (Sweden)

    S. TAS

    2013-12-01

    Full Text Available A study of the abundance and composition of microphytoplankton was carried out in marine areas of the Datça and Bozburun Peninsulas between the years 2002 and 2004. Simultaneously measured physical (salinity, temperature, secchi disc and chemical parameters (nutrients, chl-a, dissolved oxygen were assessed together with microphytoplankton data. Seawater and plankton net samples were taken from 63 stations during 6 sampling periods. A total of 132 taxa belonging to 3 taxonomic classes was reported and a checklist of microphytoplankton was prepared for this study area. Average nutrient values in surface water ranged from 0.01 to 1.19 µM for NO3+NO2–N, from 0.01 to 0.69 µM for PO4–P and from 0.50 to 5.31 µM for SiO2–Si and chl–a values were between 0.19 and 0.68 µg l–1 throughout the study area. The highest number of microphytoplankton cells reached 5400 cells l–1 and dinoflagellate Prorocentrum micans reached 1500 cells l–1 while diatom Thalassionema nitzschioides reached 700 cells l–1. Dinoflagellates showed a more homogeneous distribution in a wider area than diatoms. The dinoflagellate abundance increased in areas close to the fish farms due to the amount of nutrients originating there. Spatial changes in phytoplankton composition observed in this marine area revealed that phytoplankton are very sensitive to ecosystem changes. The study area could generally be defined as oligotrophic in terms of trophic status depending on the nutrient and chl–a concentrations. Moreover, very low cell abundance and high species richness observed in this area also reflect typical characteristics of oligotrophic waters.

  8. Do fluid inclusions preserve δ18O values of hydrothermal fluids in epithermal systems over geological time? : evidence from paleo- and modern geothermal systems, Milos island, Aegean Sea

    OpenAIRE

    Naden, Jonathan; Kilias, S.P.; M. J. Leng; Cheliotis, I.; Shepherd, T.J.

    2003-01-01

    Stable isotope compositions of quartz (δ18Oquartz) and fluid inclusion waters (δ18OFI and δDFI) were analysed from Profitis Ilias, a low-sulphidation epithermal gold mineralisation deposit on Milos island Greece, to establish if δ18OFI preserve a record of paleo-geothermal processes. Previous studies show that mineralisation at Profitis Ilias resulted from extreme boiling and vaporisation and a zone located at approximately 430 m asl represents the transition between a liquid- and vapour-dom...

  9. Trace elements, pesticides and PCBs levels in sediments of a bay influenced by anthropogenic activities (Thermaikos bay, N.W. Aegean Sea)

    International Nuclear Information System (INIS)

    Surface sediment samples recovered from the study area over a grid of 13 stations during 1995 were examined for organic carbon, Fe, Cr, Ni, Mn, Zn, Co, Cu, Pb, herbicides, DDTs and polychlorinated biphenyls (PCBs). The organic carbon was obtained according to Gaudette et al. The extraction of the metals was achieved with 2N HCl and the determination of the metal content was performed on a Perkin-Elmer 305B AAS. The pesticides and PCBs after extraction on a Soxhlet apparatus and clean-up on an alumina column were determined by gas chromatography on a Varian 3400 Gas Chromatograph equipped with TSD and ECD

  10. 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

  11. 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.

  12. 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...

  13. Isotope geochemistry of recent magmatism in the Aegean arc: Sr, Nd, Hf, and O isotopic ratios in the lavas of Milos and Santorini-geodynamic implications

    Science.gov (United States)

    Briqueu, L.; Javoy, M.; Lancelot, J.R.; Tatsumoto, M.

    1986-01-01

    In this comparative study of variations in the isotopic compositions (Sr, Nd, O and Hf) of the calc-alkaline magmas of the largest two volcanoes, Milos and Santorini, of the Aegean arc (eastern Mediterranean) we demonstrate the complexity of the processes governing the evolution of the magmas on the scale both of the arc and of each volcano. On Santorini, the crustal contamination processes have been limited, effecting the magma gradually during its differentiation. The most differentiated lavas (rhyodacite and pumice) are also the most contaminated. On Milos, by contrast, these processes are very extensive. They are expressed in the 143Nd/144Nd vs. 87Sr/86Sr diagram as a continuous mixing curve between a mantle and a crustal end member pole defined by schists and metavolcanic rocks outcropping on these volcanoes. In contrast with Santorini, the least differentiated lavas on Milos are the most contaminated. These isotopic singularities can be correlated with the geodynamic evolution of the Aegean subduction zone, consisting of alternating tectonic phases of distension and compression. The genesis of rhyolitic magmas can be linked to the two phases of distension, and the contamination of the calc-alkaline mantle-derived magmas with the intermediate compressive phase. The isotopic characteristics of uncontaminated calc-alkaline primitive magmas of Milos and Santorini are directly comparable to those of magmas generated in subduction zones for which a contribution of subducted sediments to partial melts from the mantle is suggested, such as in the Aleutian, Sunda, and lesser Antilles island arcs. However, in spite of the importance of the sediment pile in the eastern Mediterranen oceanic crust (6-10 km), the contribution of the subducted terrigenous materials remains of limited amplitude. ?? 1986.

  14. 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.

  15. 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. PMID:26396017

  16. 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.

  17. 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.

  18. Sea level trends in Southeast Asian seas

    OpenAIRE

    M. W. Strassburg; B. D. Hamlington; R. R. Leben; P. Manurung; J. Lumban Gaol; B. Nababan; Vignudelli, S.; Kim, K.-Y.

    2015-01-01

    Southeast Asian seas span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian oceans. The Southeast Asian sea regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost 2 decades. Initial comparisons of global sea level reconstructions find that 17-year sea level trends over the past 60 years exhibit good agreement with decadal variability associated...

  19. Report of the Scientific, Technical and Economic Committee for Fisheries on assessment of Merluccius merluccius, Mullus barbatus, Mullus surmuletus, Boops boops, Spicara smaris/Spicara flexuosa and Nephrops norvegicus in Aegean and Ionian waters (STECF 12-21)

    OpenAIRE

    2012-01-01

    The Ad-hoc Working Group of the Scientific, Technical and Economic Committee for Fisheries EWG worked by correspondence to conducut assessemts of Merluccius merluccius, Mullus barbatus, Mullus surmuletus, Boops boops, Spicara smaris/Spicara flexuosa and Nephrops norvegicus in Aegean and Ionian waters. The report was reviewed by the STECF during its 41st plenary held from 5 to 9 November 2012 in Brussels (Belgium).

  20. Mantle Response to Collision, Slab Breakoff & Lithospheric Tearing in Anatolian Orogenic Belts, and Cenozoic Geodynamics of the Aegean-Eastern Mediterranean Region

    Science.gov (United States)

    Dilek, Yildirim; Altunkaynak, Safak

    2010-05-01

    The geochemical and temporal evolution of the Cenozoic magmatism in the Aegean, Western Anatolian and peri-Arabian regions shows that plate tectonic events, mantle dynamics, and magmatism were closely linked in space and time. The mantle responded to collision-driven crustal thickening, slab breakoff, delamination, and lithospheric tearing swiftly, within geologically short time scales (few million years). This geodynamic continuum resulted in lateral mantle flow, whole-sale extension and accompanying magmatism that in turn caused the collapse of tectonically and magmatically weakened orogenic crust. Initial stages of post-collisional magmatism (~45 Ma) thermally weakened the orogenic crust in Tethyan continental collision zones, giving way into large-scale extension and lower crustal exhumation via core complex formation starting around 25-23 Ma. Slab breakoff was the most common driving force for the early stages of post-collisional magmatism in the Tethyan mountain belts in the eastern Mediterranean region. Magmatic rocks produced at this stage are represented by calc-alkaline-shoshonitic to transitional (in composition) igneous suites. Subsequent lithospheric delamination or partial convective removal of the sub-continental lithospheric mantle in collision-induced, overthickened orogenic lithosphere caused decompressional melting of the upwelling asthenosphere that in turn resulted in alkaline basaltic magmatism (punctuated by the collisional accretion of several ribbon continents (i.e. Pelagonia, Sakarya, Tauride-South Armenian) to the southern margin of Eurasia, and by related slab breakoff events. Exhumation of middle to lower crustal rocks and the formation of extensional metamorphic domes occurred in the backarc region of this progressively southward-migrated trench and the Tethyan (Afro-Arabian) slab throughout the Cenozoic. Thus, slab retreat played a major role in the Cenozoic geodynamic evolution of the Aegean and Western Anatolian regions. However

  1. 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.

  2. 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, Sasa; 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

  3. Estimation of critical CO2 values when planning the power source in water desalination: The case of the small Aegean islands

    International Nuclear Information System (INIS)

    Climate change is one of the most important issues our world faces today and it is responsible for a number of natural disasters that threaten human life and existence. Carbon dioxide, produced from almost every energy consuming activity, is the dominant greenhouse gas responsible for global warming. Water desalination is an energy intensive activity, and when it is powered by conventional energy sources, significant amounts of CO2 are released. For every cubic metre of fresh water produced, there is a 2 kg of CO2 reduction if renewable energy sources (RES) are used instead of electricity from the local grid. On the other hand, the cost of fresh water produced by desalination is much less if conventional sources of energy are used. Making appropriate policy choices require information on both costs and benefits. So here we estimate the critical CO2 cost, above which desalination units should use renewable energy instead of conventional energy sources. It was found that the critical CO2 emissions cost can be close to the CO2 capture cost and in many cases less than the penalties imposed by the European Commission. Several case studies of water desalination in the Aegean islands verify the conclusions.

  4. 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

    2016-01-01

    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. PMID:27395920

  5. 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

  6. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki; Outola, Iisa; Ikäheimonen, Tarja; Mattila, Jukka; Herrmann, Jürgen; Kanisch, Günter; Osvath, Iolanda

    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. Radi...... seawater; only the Irish Sea and the Black Sea show higher levels. In 1990, average concentrations of 137Cs in fish from the Baltic Sea were similar to those in the Irish Sea, about 4 times higher than in the Black Sea and about 30 times higher than in the Mediterranean Sea....

  7. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki; Outola, Iisa; Ikäheimonen, Tarja; Mattila, Jukka; Herrmann, Jürgen; Kanisch, Günter; Osvath, Iolanda

    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...... seawater; only the Irish Sea and the Black Sea show higher levels. In 1990, average concentrations of 137Cs in fish from the Baltic Sea were similar to those in the Irish Sea, about 4 times higher than in the Black Sea and about 30 times higher than in the Mediterranean Sea....

  8. 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.

  9. 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.

  10. 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.

  11. 137 Caesium distribution in the eastern Mediterranean Sea. Recent changes and future trends

    International Nuclear Information System (INIS)

    A series of sampling campaigns were carried out in the eastern Mediterranean in the period 1995-1997, to examine the relationship between the distribution of 137Cs in the water column and water mass circulation. 137Cs concentration in the surface water ranges between 3.3 and 4.0 mBq/l all over the area, indicating that the input due to the Chernobyl accident has been transferred to deep water layers by convection processes. In fact, in the vertical profiles, relative maxima are observed in the intermediate (4 mBq/l) and deep waters (∼2.5 mBq/l) formed after the Chernobyl accident. A clear Chernobyl signal also traces the new deep waters formed in the Aegean Sea that, exiting from the Cretan Arc Straits, since 1991 are spreading in the bottom layer of the eastern Mediterranean. The changes in 137Cs vertical profiles related to the new thermohaline circulation of the intermediate and deep waters of the eastern Mediterranean are being monitored at a deep station in the western Ionian Sea. The 1997 profile shows a decrease in 137Cs concentration both in the Levantine intermediate water and in the eastern Mediterranean deep water with respect to 1996. The decrease in Levantine intermediate water is likely due to seasonal/interannual variability, while the changes in the deep layer are related to the spreading westward into the Ionian of the new Aegean dense water. Along the path towards the western Mediterranean, 137Cs content in the Levantine intermediate water decreases from ∼4 mBq/l in the W-Ionian Sea to ∼2 mBq/l at the western sill of the Sicily Straits, due to mixing with underlying water, with lower caesium content, near the Malta Sill. Time-series measurements at the western sill of the Sicily Straits show that, while 137Cs concentration in the surface water entering the eastern Mediterranean remained constant (∼3.5 mBq/l) in the period 1993-1997, its level in the Levantine intermediate water leaving the basin decreased from 3.5 to 2.0 mBq/l

  12. {sup 137} Caesium distribution in the eastern Mediterranean Sea. Recent changes and future trends

    Energy Technology Data Exchange (ETDEWEB)

    Papucci, C.; Delfanti, R. [ENEA, Marine Environment Research Centre, P.O. Box 316, 19100 La Spezia (Italy)

    1999-09-30

    A series of sampling campaigns were carried out in the eastern Mediterranean in the period 1995-1997, to examine the relationship between the distribution of 137Cs in the water column and water mass circulation. 137Cs concentration in the surface water ranges between 3.3 and 4.0 mBq/l all over the area, indicating that the input due to the Chernobyl accident has been transferred to deep water layers by convection processes. In fact, in the vertical profiles, relative maxima are observed in the intermediate (4 mBq/l) and deep waters ({approx}2.5 mBq/l) formed after the Chernobyl accident. A clear Chernobyl signal also traces the new deep waters formed in the Aegean Sea that, exiting from the Cretan Arc Straits, since 1991 are spreading in the bottom layer of the eastern Mediterranean. The changes in 137Cs vertical profiles related to the new thermohaline circulation of the intermediate and deep waters of the eastern Mediterranean are being monitored at a deep station in the western Ionian Sea. The 1997 profile shows a decrease in 137Cs concentration both in the Levantine intermediate water and in the eastern Mediterranean deep water with respect to 1996. The decrease in Levantine intermediate water is likely due to seasonal/interannual variability, while the changes in the deep layer are related to the spreading westward into the Ionian of the new Aegean dense water. Along the path towards the western Mediterranean, 137Cs content in the Levantine intermediate water decreases from {approx}4 mBq/l in the W-Ionian Sea to {approx}2 mBq/l at the western sill of the Sicily Straits, due to mixing with underlying water, with lower caesium content, near the Malta Sill. Time-series measurements at the western sill of the Sicily Straits show that, while 137Cs concentration in the surface water entering the eastern Mediterranean remained constant ({approx}3.5 mBq/l) in the period 1993-1997, its level in the Levantine intermediate water leaving the basin decreased from 3.5 to 2

  13. Population Genetic Structure of red mullet (Mullus barbatus L. in Turkish Sea Based on Mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Fevzi Bardakci

    2014-06-01

    Full Text Available Aim: Mullus barbatus (red mullet is a commercial fish species naturally distributed from Eastern Atlantic: British Isles to Dakar, Senegal, Canary Islands, Mediterranean and Black Sea. There is no study in our knowledge aimed to determine population genetic structuring and genetic stocks of M. barbatus species in territorial waters of Turkey. Only a few studies have been carried out on their genetics in Turkey which are limited to determination of phylogenetic relationships between species in familia of Mullidae. In this study population genetic structure and genetic diversity of red mullet (Mullus barbatus L. in Turkish Seas was determined using sequence data of mitochondrial DNA control region. Material and Methods: Red mullet sample were collected from the Mediterranean Sea (Mersin, Antalya, the Aegean Sea (Ayvalık, Marmara Sea (Bandırma, the Black Sea (Zonguldak, Trabzon, Fatsa and Hopa. mtDNA control region of 410 bp in length were amplified and subsequently sequenced. The sequences were aligned in Bioedit ver 7.1.3.0 (Hall, 1999. Genetic distance between populations (γst (Nei, 1982, haplotype diversities (h, nucleotide diversities(π were detected by DNAsp ver. 5.10 (Rozas et al., 2003. Based on pairwise distance matrix data a UPGMA dendogram was constructed by MEGA 5.05 (Kumar et al., 2004. To explain genetic structuring of samples we performed analysis of molecular variance (AMOVA using Arlequin ver. 3.5 (Excoffier et al., 2010. Results: In total 190 individuals were studied and alignment of partial control region of mtDNA revealed 98 mtDNA haplotypes with 75 polymorphic sites. The average of nucleotide diversities and haplotype diversities were calculated 0,015 and 0,963 respectively. Haplotype and nucleotide (π diversities among the populations ranged from 0,907 (Zonguldak to 0,972 (Trabzon and from 0.0155 (Trabzon to 0,0114 (Bandırma, respectively. Distance tree based on gammast pairwise comparisons revealed two main clades, the

  14. Aral Sea basin: a sea dies, a sea also rises.

    Science.gov (United States)

    Glantz, Michael H

    2007-06-01

    The thesis of this article is quite different from many other theses of papers, books, and articles on the Aral Sea. It is meant to purposely highlight the reality of the situation in Central Asia: the Aral Sea that was once a thriving body of water is no more. That sea is dead. What does exist in its place are the Aral seas: there are in essence three bodies of water, one of which is being purposefully restored and its level is rising (the Little Aral), and two others which are still marginally connected, although they continue to decline in level (the Big Aral West and the Big Aral East). In 1960 the level of the sea was about 53 m above sea level. By 2006 the level had dropped by 23 m to 30 m above sea level. This was not a scenario generated by a computer model. It was a process of environmental degradation played out in real life in a matter of a few decades, primarily as a result of human activities. Despite wishes and words to the contrary, it will take a heroic global effort to save what remains of the Big Aral. It would also take a significant degree of sacrifice by people and governments in the region to restore the Big Aral to an acceptable level, given that the annual rate of flow reaching the Amudarya River delta is less than a 10th of what it was several decades ago. Conferring World Heritage status to the Aral Sea(s) could spark restoration efforts for the Big Aral. PMID:17626470

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. Distribution patterns of carbon oxidation in the eastern Mediterranean Sea: Evidence of changes in the remineralization processes

    Science.gov (United States)

    La Ferla, Rosabruna; Azzaro, Maurizio; Civitarese, Giuseppe; Ribera D'Alcalã, Maurizio

    2003-09-01

    Deep remineralization patterns, as carbon dioxide production, were investigated in microplankton samples from several areas of eastern Mediterranean Sea. The respiration data, collected during six oceanographic surveys from 1993 through 1999, evidence biogeochemical peculiarities of the deep waters of Mediterranean as compared to the open ocean and allow drawing up an hypothesis on the possible impact of the Eastern Mediterranean Transient (EMT) on remineralization processes. The temporal trend of the oxidative processes in the basin is tightly coupled with the main features of the circulation pattern. In the Mediterranean Sea, the convective processes and the consequent advection of dense waters assume a relevant role in sustaining the amount of remineralization in the deep layers and appear to be more important than the sinking of particulate matter from the upper layers. Respiration in the deepest Mediterranean waters accounts for a greater percentage of the upper aphotic zone respiration (over 45%) than that found in the open oceans (below 21%). In addition, the increase in respiratory rates in only a few years in the Ionian Basin could represent a signal of the changes induced by the EMT, which replaced the Adriatic deepwater supply with waters of Aegean origin. The ecological change induced by the EMT, negligible in the photic layers of the eastern Mediterranean Sea, seems to concern the impact of the continental shelf pump by advection of younger, less-refractory organic matter utilizable by deep biota.

  20. Microbial respiration in the Levantine Sea: evolution of the oxidative processes in relation to the main Mediterranean water masses

    Science.gov (United States)

    La Ferla, Rosabruna; Azzaro, Maurizio

    2001-10-01

    First data on microbial respiration in the Levantine Sea are reported with the aim of assessing the distribution of oxidative processes in association with the main Mediterranean water masses and the changing physical structure determined by the Eastern Mediterranean Transient. Respiratory rates, in terms of metabolic carbon dioxide production, were estimated from measured electron transport system activities in the polygonal area of the Levantine Sea (32.5-36.5 N Latitude, 26.0-30.25 E Longitude) and at Station Geo'95, in the Ionian Sea (35°34.88 N; 17°14.99 E). At the Levantine Sea, the mean carbon dioxide production rate decreased from the upper to the deeper layers and varied from 22.0±12.4 μg C h -1 m -3 in the euphotic layer to 1.30±0.5 μg C h -1 m -3 in the depth range between 1600 and 3000 m. Significant differences were found among upper, intermediate and bottom layers. The euphotic zone supported a daily carbon dioxide production of 96.6 mg C d -1 m -2 while the aphotic zone (between 200 and 3000 m) sustained a 177.1 mg C d -1 m -2 carbon dioxide production. In Station Geo'95, the carbon dioxide production rates amounted to 170.4 and 102.2 mg C d -1 m -2 in the euphotic and aphotic zones, respectively. The rates determined in the identified water masses showed a tight coupling of respiratory processes and Mediterranean circulation patterns. The increasing respiratory rates in the deep layers of the Levantine Sea are explained by the introduction of younger waters recently formed in the Aegean Sea.

  1. Sea level rise

    OpenAIRE

    Warrick, R. A.; Oerlemans, J.

    1990-01-01

    This Section addresses three questions: Has global-mean sea level been rising during the last 100 years? What are the causal factors that could explain a past rise in sea level? And what increases in sea level can be expected in the future?

  2. Climatological variations of total alkalinity and total inorganic carbon in the Mediterranean Sea surface waters

    Directory of Open Access Journals (Sweden)

    E. Gemayel

    2015-08-01

    Full Text Available A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT and total inorganic carbon (CT from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE of ±10.6 μmol kg−1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg−1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005–2012 mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  3. Petrogenetic evolution of the Early Miocene Alaçamdağ volcano-plutonic complex, northwestern Turkey: implications for the geodynamic framework of the Aegean region

    Science.gov (United States)

    Erkül, Sibel Tatar

    2012-01-01

    Extensional-tectonic processes have generated extensive magmatic activity that produced volcanic/plutonic rocks along an E-W-trending belt across north-western Turkey; this belt includes granites and coeval volcanic rocks of the Alaçamdağ volcano-plutonic complex. The petrogenesis of the Early Miocene Alaçamdağ granitic and volcanic rocks are here investigated by means of whole-rock Sr-Nd isotopic data along with field, petrographic and whole-rock geochemical studies. Geological and geochemical data indicate two distinct granite facies having similar mineral assemblages, their major distinguishing characteristic being the presence or absence of porphyritic texture as defined by K-feldspar megacrysts. I-type Alaçamdağ granitic stocks have monzogranitic-granodioritic compositions and contain a number of mafic microgranular enclaves of monzonitic, monzodioritic/monzogabbroic composition. Volcanic rocks occur as intrusions, domes, lava flows, dykes and volcanogenic sedimentary rocks having (first episode) andesitic and dacitic-trachyandesitic, and (second episode) dacitic, rhyolitic and trachytic-trachydacitic compositions. These granitic and volcanic rocks are metaluminous, high-K, and calc-alkaline in character. Chondrite-normalised rare earth element patterns vary only slightly such that all of the igneous rocks of the Alaçamdağ have similar REE patterns. Primitive-mantle-normalised multi-element diagrams show that these granitic and volcanic rocks are strongly enriched in LILE and LREE pattern, high (87Sr/86Sr)i and low ɛ Nd( t) ratios suggesting Alaçamdağ volcano-plutonic rocks to have been derived from hybrid magma that originated mixing of co-eval lower crustal-derived more felsic magma and enriched subcontinental lithospheric mantle-derived more mafic magmas during extensional processes, and the crustal material was more dominant than the mantle contribution. The Alaçamdağ volcano-plutonic complex rocks may form by retreat of the Hellenic/Aegean

  4. Waves in the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    of wave-energy for generation of electricty. Wind while blowing over the sea surface trans- fers huge amounts of energy into the sea by imparting oscillatory motion to the surface. This includes both ki- netic and potential Chaotic sea surface; (inset) a... stimulation and excite- ment since it has much complexity and scope for further developments. The recently developed wonder-tool of mathematics, 'fractals' can also be used to model sea surfaces. Generation of waves on the sea surface is a very complex process...

  5. 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

  6. Changes in ventilation of the Mediterranean Sea during the past 25 yr

    Directory of Open Access Journals (Sweden)

    A. Schneider

    2013-08-01

    Full Text Available The Mediterranean Sea has a fast overturning circulation and the deep water masses are well ventilated in comparison to the deep waters of the world ocean. Significant changes in the overturning circulation has been observed during the last few decades, the most prominent phenomena being the Eastern Mediterranean Transient (EMT in the early 1990s and the Western Mediterranean Transit (WMT near the mid of the decade following. During both of these events unusually large amounts of deep water were formed, and in the case of the EMT, the deep water formation area shifted from the Adriatic to the Aegean Sea. This variability is important to understand and to monitor, because ventilation is the main process to propagate surface perturbations, such as uptake of anthropogenic CO2, into the ocean interior. Here we synthesize a unique collection of transient tracer (CFC-12, SF6 and tritium data from nine cruises conducted between 1987 and 2011 and use these data to determine temporal variability of Mediterranean ventilation. We also discuss biases and technical problems with transient tracer-based ages arising from their different input histories over time; particularly in the case of time-dependent ventilation. We observe a period of stagnation in the deep eastern (Levantine basin after it was ventilated by the EMT so that the age of the deep water is increasing with time. In the Ionian Sea, on the other hand, we see evidence of increased ventilation after year 2001, indicating the restarted deep water formation in the Adriatic Sea. This is also reflected in the increasing age of the Cretan Sea deep water and decreasing age of Adriatic Sea deep water since the end of the 1980s. In the western Mediterranean deep basin we see the massive input of recently ventilated waters during the WMT. This signal is not yet apparent in the Tyrrhenian Sea, where the ventilation seems to be fairly constant since the EMT. Also the western Alboran Sea does not show any

  7. Sea level report

    International Nuclear Information System (INIS)

    Study of Cenozoic Era sea levels shows a continual lowering of sea level through the Tertiary Period. This overall drop in sea level accompanied the Pleistocene Epoch glacio-eustatic fluctuations. The considerable change of Pleistocene Epoch sea level is most directly attributable to the glacio-eustatic factor, with a time span of 105 years and an amplitude or range of approximately 200 m. The lowering of sea level since the end of the Cretaceous Period is attributed to subsidence and mid-ocean ridges. The maximum rate for sea level change is 4 cm/y. At present, mean sea level is rising at about 3 to 4 mm/y. Glacio-eustacy and tectono-eustacy are the parameters for predicting sea level changes in the next 1 my. Glacio-eustatic sea level changes may be projected on the basis of the Milankovitch Theory. Predictions about tectono-eustatic sea level changes, however, involve predictions about future tectonic activity and are therefore somewhat difficult to make. Coastal erosion and sedimentation are affected by changes in sea level. Erosion rates for soft sediments may be as much as 50 m/y. The maximum sedimentation accumulation rate is 20 m/100 y

  8. Sea level extremes in the Caribbean Sea

    OpenAIRE

    Torres, R. Ricardo; Tsimplis, Michael N.

    2014-01-01

    Sea level extremes in the Caribbean Sea are analyzed on the basis of hourly records from 13 tide gauges. The largest sea level extreme observed is 83 cm at Port Spain. The largest nontidal residual in the records is 76 cm, forced by a category 5 hurricane. Storm surges in the Caribbean are primarily caused by tropical storms and stationary cold fronts intruding the basin. However, the seasonal signal and mesoscale eddies also contribute to the creation of extremes. The five stations that have...

  9. 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 ...

  10. 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. PMID:27459093

  11. 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....

  12. 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.

  13. Climate Impacts on Sea Turtle Breeding Phenology in Greece and Associated Foraging Habitats in the Wider Mediterranean Region

    Science.gov (United States)

    Morreale, Stephen J.; Saba, Vincent S.; Panagopoulou, Aliki; Margaritoulis, Dimitris; Spotila, James R.

    2016-01-01

    Sea turtles are vulnerable to climate change impacts in both their terrestrial (nesting beach) and oceanic habitats. From 1982 to 2012, air and sea surface temperatures at major high use foraging and nesting regions (n = 5) of loggerhead turtles (Caretta caretta) nesting in Greece have steadily increased. Here, we update the established relationships between sea surface temperature and nesting data from Zakynthos (latitude: 37.7°N), a major nesting beach, while also expanding these analyses to include precipitation and air temperature and additional nesting data from two other key beaches in Greece: Kyparissia Bay (latitude: 37.3°N) and Rethymno, Crete (latitude: 35.4°N). We confirmed that nesting phenology at Zakynthos has continued to be impacted by breeding season temperature; however, temperature has no consistent relationship with nest numbers, which are declining on Zakynthos and Crete but increasing at Kyparissia. Then using statistically downscaled outputs of 14 climate models assessed by the Intergovernmental Panel on Climate Change (IPCC), we projected future shifts in nesting for these populations. Based on the climate models, we projected that temperature at the key foraging and breeding sites (Adriatic Sea, Aegean Sea, Crete, Gulf of Gabès and Zakynthos/Kyparissia Bay; overall latitudinal range: 33.0°—45.8°N) for loggerhead turtles nesting in Greece will rise by 3–5°C by 2100. Our calculations indicate that the projected rise in air and ocean temperature at Zakynthos could cause the nesting season in this major rookery to shift to an earlier date by as much as 50–74 days by 2100. Although an earlier onset of the nesting season may provide minor relief for nest success as temperatures rise, the overall climatic changes to the various important habitats will most likely have an overall negative impact on this population. PMID:27332550

  14. 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

  15. 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

  16. The M3A multi-sensor buoy network of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    K. Nittis

    2006-08-01

    Full Text Available A network of three multi-sensor timeseries stations able to deliver real time physical and biochemical observations of the upper thermocline has been developed for the needs of the Mediterranean Forecasting System during the MFSTEP project. They follow the experience of the prototype M3A system that was developed during the MFSPP project and has been tested during a pilot pre-operational period of 22 months (2000–2001. The systems integrate sensors for physical (temperature, salinity, turbidity, current speed and direction as well as optical and chemical observations (dissolved oxygen, chlorophyll-a, PAR, nitrate. The south Aegean system (E1-M3A follows a modular design using independent mooring lines and collects biochemical data in the upper 100 m and physical data in the upper 500 m of the water column. The south Adriatic buoy system (E2-M3A uses similar instrumentation but on a single mooring line and also tests a new method of pumping water samples from relatively deep layers, performing analysis in the protected ''dry'' environment of the buoy interior. The Ligurian Sea system (W1-M3A is an ideal platform for air-sea interaction processes since it hosts a large number of meteorological sensors while its ocean instrumentation, with real time transmission capabilities, is confined in the upper 50 m layer. Despite their different architecture, the three systems have common sampling strategy, quality control and data management procedures. The network operates in the Mediterranean Sea since autumn 2004 collecting timeseries data for calibration and validation of the forecasting system as well for process studies of regional dynamics.

  17. The M3A multi-sensor buoy network of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    F. Zanon

    2007-05-01

    Full Text Available A network of three multi-sensor timeseries stations able to deliver real time physical and biochemical observations of the upper thermocline has been developed for the needs of the Mediterranean Forecasting System during the MFSTEP project. They follow the experience of the prototype M3A system that was developed during the MFSPP project and has been tested during a pilot pre-operational period of 22 months (2000–2001. The systems integrate sensors for physical (temperature, salinity, turbidity, current speed and direction as well as optical and chemical observations (dissolved oxygen, chlorophyll-a, PAR, nitrate. The south Aegean system (E1-M3A follows a modular design using independent mooring lines and collects biochemical data in the upper 100 m and physical data in the upper 500 m of the water column. The south Adriatic buoy system (E2-M3A uses similar instrumentation but on a single mooring line and also tests a new method of pumping water samples from relatively deep layers, performing analysis in the protected "dry" environment of the buoy interior. The Ligurian Sea system (W1-M3A is an ideal platform for air-sea interaction processes since it hosts a large number of meteorological sensors while its ocean instrumentation, with real time transmission capabilities, is confined in the upper 50 m layer. Despite their different architecture, the three systems have common sampling strategy, quality control and data management procedures. The network operates in the Mediterranean Sea since autumn 2004 collecting timeseries data for calibration and validation of the forecasting system as well for process studies of regional dynamics.

  18. 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)...

  19. The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas

    Directory of Open Access Journals (Sweden)

    E. Athanasopoulou

    2008-10-01

    Full Text Available Open-ocean and surf-zone sea-salt aerosol (SSA emission parameterizations are incorporated in the CAMx aerosol model and applied over an area with an extended Archipelago (Greece, with a fine grid nested over the highly populated Attica peninsula. The maximum indirect impact of SSA on PM10 mass (35% is located over a marine area with moderate SSA production and elevated shipping emissions (central Aegean Sea where SSA interacts with anthropogenic nitric acid forming sodium nitrate. SSA increases PM10 levels in the Athens city center up to 25% during stable onshore winds. Under such conditions both open-ocean and surf-zone mechanisms contribute to aerosol production over Attica. A hybrid scheme for gas-to-particle mass transfer is necessary for accurately simulating semi-volatile aerosol components when coarse SSA is included. Dynamically simulating mass transfer to the coarse particles leads to a quadrupling of predicted PM10 nitrate in the Athens city center and up to two orders of magnitude in its coarse mass in comparison to using a bulk equilibrium approach.

  20. The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas

    Directory of Open Access Journals (Sweden)

    E. Athanasopoulou

    2008-02-01

    Full Text Available Open-ocean and surf-zone sea-salt aerosol (SSA emissions algorithms are incorporated in the CAMx aerosol model and applied over an area with an extended Archipelago (Greece, with a fine grid nested over the highly populated Attica peninsula. The maximum indirect impact of SSA on PM10 mass (35% is located over a marine area with moderate SSA production and elevated shipping emissions (central Aegean Sea where SSA interacts with anthropogenic nitric acid forming sodium nitrate. SSA increases PM10 levels in the Athens city center up to 27% during stable onshore winds. Under such conditions both open-ocean and surf-zone mechanisms contribute to aerosol production over Attica. A hybrid scheme for gas-to-particle mass transfer is necessary for accurately simulating semi-volatile aerosol components when coarse SSA is included. Dynamically simulating mass transfer to the coarse particles leads to a quadrupling of predicted PM10 nitrate in the Athens city center and up to two orders of magnitude in its coarse mass in comparison to using a bulk equilibrium approach.

  1. Oceanography of marginal seas

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    . The Andaman Sea remains the least studied basin in this region. Physical and chemical signatures suggest that the deep basin of the Andaman Sea are largely influenced by intermediate circulation. Deep waters are warmer and low in oxygen than those at similar...

  2. SEA and planning

    DEFF Research Database (Denmark)

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

    2009-01-01

    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...

  3. 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...

  4. Motorways of the Sea

    OpenAIRE

    Ionita Profir

    2011-01-01

    In its communication aim, the European Commission presents the following definition: short distance shipping means the movement of cargo and passengers by sea between ports situated in Europe geographical area or between those ports and ports situated in non-European countries located at closed seas on the border of Europe

  5. North Sea update

    International Nuclear Information System (INIS)

    The article deals with the offshore activity in the North Sea bringing together a special update feature for the petroleum industries in the United Kingdom, Norway, Denmark and the Netherlands. The total capital expenditure required for the period from 1995 to 1998 for the North Sea area which includes exploration, development projects and well abandoning, are discussed and presented. 20 figs., 5 tabs

  6. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg; Melsheimer, Christian; Pedersen, Leif Toudal; Schyberg, Harald; Tveter, Frank; Dahlgren, Per; Lundelius, Tomas; Gustafsson, Nils

    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...

  7. Development of a two-layer mathematical model for the study of hydrodynamic circulation in the sea. Application to the Thermaikos gulf

    Directory of Open Access Journals (Sweden)

    M.G. DODOU

    2012-12-01

    Full Text Available A two-layer hydrodynamic model for stratified flows has been developed and applied to the study of the sea water circulation in the Thermaikos Gulf (North Aegean Sea in the east Mediterranean Sea. The model was based on the finite differences method. The wind and Coriolis forces applied to a stratified basin (with initial density differences ΆΪ/Ϊ = 5ς constituted the basic factors for the study of the circulation in the gulf, corresponding to the stratification conditions. The findings of the model, concerning the basic pattern of circulation in the gulf, were in accordance with in situ data collected in previous studies of the area. Furthermore, the application of the model allowed for the tracking and recognition of the regions of upwelling in the gulf, which were related to the prevailing wind conditions. For the integration of the research, the study was complemented with runs of a two dimensional – depth averaged- model which corresponded to nonstratified conditions. Comparisons and evaluation of the results of the simulations close the study.

  8. Decadal variability of the Turner Angle in the Mediterranean Sea and its implications for double diffusion

    Science.gov (United States)

    Meccia, Virna L.; Simoncelli, Simona; Sparnocchia, Stefania

    2016-08-01

    The physical reanalysis component of the Mediterranean Forecasting System is used to construct a high-resolution three-dimensional atlas of the Turner Angle. An assessment of the model quality shows a maximum degree of agreement with observations in the water column between 150 and 1000 m depth. The mean state of the favourable conditions for double diffusion processes is evaluated and the recent decadal variability is studied in terms of changes in the water mass properties. The results show that approximately 50% of the Mediterranean Sea is favourable to double diffusion processes, from which around 47% is associated with salt fingering. The Tyrrhenian, Ionian and southwestern Mediterranean are the most vulnerable basins to salt fingering, and the strongest processes can occur in the Tyrrhenian deep waters. Diffusive convection is most likely to occur in the Ionian, Aegean and eastern Mediterranean at vertical levels deeper than 1000 m. The observed gradual warming and salinification of the Mediterranean after 1997 decreased and increased the possibilities of the occurrence of salt fingers and double diffusive convections, respectively. The climatological atlas that is presented in this paper provides a three-dimensional picture of the regions that are either doubly stable or favourable to double diffusion instability and allows for the characterization of the diffusive properties of the water masses.

  9. Species identification of small pelagic fish schools by means of hydroacoustics in the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    K. TSAGARAKIS

    2015-01-01

    Full Text Available   Reliable biomass estimates by means of hydroacoustics largely depend on the correct identification of acoustic targets. Data collected during five summer acoustic surveys (2004-2008 in the North Aegean Sea (Greece were analyzed to explore effective discrimination of small pelagic fish schools according to the species they belong. Discriminant Function Analyses (DFA using bathymetric, energetic and morphometric school descriptors as explanatory variables were applied per research cruise as well as to pooled data from all surveys. Results revealed that the schools can be successfully classified into the five species considered (anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, blue whiting Micromessistius poutassou, and Atlantic mackerel Scomber scombrus. The percentage of correct classifications in terms of number of schools was higher in the analyses of the annual cruises (75.6%-95.36% than in the analysis of pooled data (≈72%. This is because of (i the lower number of species, as well as (ii the reduced intraspecific variability, occurring in each separate cruise. Significant differences were detected among school descriptors for the different species, revealing discrete aspects of schooling behaviour for each species. The benefit of the specific approach is that the classification functions of the DFAs can be used to classify a larger set of schools, which has not been possible to assign to specific species. Overall the approach constitutes an objective, more automated and less time consuming procedure for the analysis of acoustic data and can contribute to the improvement of biomass estimates in the area.

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

    International Nuclear Information System (INIS)

    Highlights: • The first comprehensive study regarding radioactivity in Turkish marine environment. • Assessment of several radionuclides in mussel Mytilus galloprovincialis. • Estimation of possible risks due to 210Po for public health. • Using active and passive biomonitoring for determination of radioactivity. • Comparing the results with previous studies from Turkey and other countries. - Abstract: 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

  11. Large-scale spatio-temporal monitoring highlights hotspots of demersal fish diversity in the Mediterranean Sea

    Science.gov (United States)

    Granger, Victoria; Fromentin, Jean-Marc; Bez, Nicolas; Relini, Giulio; Meynard, Christine N.; Gaertner, Jean-Claude; Maiorano, Porzia; Garcia Ruiz, Cristina; Follesa, Cristina; Gristina, Michele; Peristeraki, Panagiota; Brind'Amour, Anik; Carbonara, Pierluigi; Charilaou, Charis; Esteban, Antonio; Jadaud, Angélique; Joksimovic, Aleksandar; Kallianiotis, Argyris; Kolitari, Jerina; Manfredi, Chiara; Massuti, Enric; Mifsud, Roberta; Quetglas, Antoni; Refes, Wahid; Sbrana, Mario; Vrgoc, Nedo; Spedicato, Maria Teresa; Mérigot, Bastien

    2015-01-01

    Increasing human pressures and global environmental change may severely affect the diversity of species assemblages and associated ecosystem services. Despite the recent interest in phylogenetic and functional diversity, our knowledge on large spatio-temporal patterns of demersal fish diversity sampled by trawling remains still incomplete, notably in the Mediterranean Sea, one of the most threatened marine regions of the world. We investigated large spatio-temporal diversity patterns by analysing a dataset of 19,886 hauls from 10 to 800 m depth performed annually during the last two decades by standardised scientific bottom trawl field surveys across the Mediterranean Sea, within the MEDITS program. A multi-component (eight diversity indices) and multi-scale (local assemblages, biogeographic regions to basins) approach indicates that only the two most traditional components (species richness and evenness) were sufficient to reflect patterns in taxonomic, phylogenetic or functional richness and divergence. We also put into question the use of widely computed indices that allow comparing directly taxonomic, phylogenetic and functional diversity within a unique mathematical framework. In addition, demersal fish assemblages sampled by trawl do not follow a continuous decreasing longitudinal/latitudinal diversity gradients (spatial effects explained up to 70.6% of deviance in regression tree and generalised linear models), for any of the indices and spatial scales analysed. Indeed, at both local and regional scales species richness was relatively high in the Iberian region, Malta, the Eastern Ionian and Aegean seas, meanwhile the Adriatic Sea and Cyprus showed a relatively low level. In contrast, evenness as well as taxonomic, phylogenetic and functional divergences did not show regional hotspots. All studied diversity components remained stable over the last two decades. Overall, our results highlight the need to use complementary diversity indices through different

  12. Intermittent Sea Level Acceleration

    OpenAIRE

    Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Spada, G.; Dipartimento di Scienze di Base e Fondamenti, Università di Urbino Carlo Bo, Urbino

    2013-01-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea{level acceleration for the last 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, con firm the existence of a global sea level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0:01 mm/yr2. However, di fferently from previous studies, we discuss how change points or ...

  13. Changes in Sea Level

    OpenAIRE

    Church, J.A.; Gregory, J. M.; Huybrechts, Philippe; Kuhn, M.; Lambeck, K.; Nhuan, M. T.; Qin, D.; Woodworth, P. L.

    2001-01-01

    This chapter assesses the current state of knowledge of the rate of change of global-averaged and regional sea-level in relation to climate change. We focus on the 20th and 21st centuries.However, because of the slow response to past conditions of the oceans and ice sheets and the consequent land movements, we consider changes in sea level prior to the historical record, andwe also look over a thousand years into the future.Past changes in sea levelFrom recent analyses, our conclusions are as...

  14. Caspian sea: petroleum challenges

    International Nuclear Information System (INIS)

    The Caspian sea is one of the world areas the most promising in terms of investments and petroleum development. This study presents the petroleum challenges generated by this hydrocarbons reserve. The first part discusses the juridical status (sea or lake), the petroleum and the gas reserves, the ecosystem and the today environment (fishing and caviar), the geostrategic situation and the transport of gas and oil. It provides also a chronology from 1729 to 2005, a selection of Internet sites, books and reports on the subject and identity sheets of the countries around the Caspian sea. (A.L.B.)

  15. Surviving the Messinian Salinity Crisis? Divergence patterns in the genus Dendropoma (Gastropoda: Vermetidae) in the Mediterranean Sea.

    Science.gov (United States)

    Calvo, Marta; Alda, Fernando; Oliverio, Marco; Templado, José; Machordom, Annie

    2015-10-01

    Four genetically distinct clades were recently described under the name Dendropoma petraeum, a Mediterranean endemic vermetid gastropod. The aim of this work is to date the processes that drove to the diversification within this taxon and to relate them to the corresponding historical events occurred in the Mediterranean Sea. Sequences from mitochondrial and nuclear markers were obtained from specimens collected in 29 localities spanning over 4000km across the entire distribution range of D. petraeum species complex. The phylogenetic and coalescent-based analyses confirmed the four well-supported and largely differentiated lineages of D. petraeum, clearly delimited geographically along a west-east axis within the Mediterranean Sea: Western, Tyrrhenian-Sicilian, Ionian-Aegean and Levantine lineages. Divergence time estimates, obtained using a range of known substitution rates for other marine gastropods, indicated two main stages of diversification. In the first period (between 9.5 and 4.5mya), the ancestral D. petraeum diverged into the current four lineages. The most recent period occurred between 3.72 and 0.66mya in the late Pliocene-early Pleistocene, and included the main within-lineage diversification events. Therefore, if the divergence time between the major lineages of Dendropoma in the Mediterranean actually predated or coincided with the Messinian Salinity Crisis, then they should have survived to this dramatic period within the Mediterranean, as supported by Bayes Factors model comparison. Conversely, if the divergence started after the crisis, congruent with the idea that no true marine organism survived the Messinian Salinity Crisis, then our results indicate substitution rates of Dendropoma much higher than usual (5.16% per million years for COI, 3.04% for 16S). More recent climate changes seem to have conditioned the demographic history of each lineage differently. While Western and Tyrrhenian-Sicilian lineages both underwent an increase in their

  16. 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...

  17. 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...

  18. South China Sea

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chinese Foreign Minister Yang Jiechi warned against attempts to "in-ternationalize" the issue of the South China Sea, where China has territorial disputes with some ASEAN member states, including Viet Nam and the

  19. Black Sea aerosols

    International Nuclear Information System (INIS)

    Shipboard, high volume air particulate samples were collected from the Black Sea atmosphere and analyzed by instrumental neutron activation analysis, atomic absorption spectrophotometry and ion chromatography for about 40 elements and ions. Concentrations of elements in the eastern and western parts of the Black Sea are different at the 95% confidence level, with lower concentrations in the eastern Black Sea. Back-trajectories and concentrations of elements in trajectory groups show that Europe accounts for more than 70% of the anthropogenic elements in the atmosphere. The average sulfate concentration was 7 μg/m3, which is comparable with rural sulfate levels in western Europe. Fluxes of elements from the atmosphere to the Black Sea are in good agreement with the results of similar flux calculations for other regions

  20. Mediterranean sea level variations.

    Science.gov (United States)

    Vigo, I.; Sánchez Reales, J. M.; García, D.; Chao, B. F.

    2009-04-01

    In this work we report an updated study of the sea level variations for the Mediterranean sea for the period from October 1992 to January 2008. The study addresses two mayor issues: (i)The analysis of the spatial and temporal variability of sea surface height (SSH) from radar altimetry measurements (from TOPEX/Poseidon (T/P) + Jason-1, etc.). We use EOF analysis to explain most of its interannual variation, and how the different basins interact. (ii) The analysis of dynamics and balance of water mass transport for the whole period. We estimate the steric SSH by combining the steric SSH estimated from temperature and salt profiles simulated by the ECCO model with time-variable gravity (TVG) data (from GRACE) for the Mediterranean Sea. The estimated steric SSH together with the SSH obtained from altimetry allow for a more realistic estimation of the water mass variations in the Mediterranean for the whole period.

  1. ROE Sea Level Relative

    Data.gov (United States)

    U.S. Environmental Protection Agency — This point dataset represents changes in relative sea level along U.S. coasts, 1960-2013. Data were provided by the National Oceanic and Atmospheric Administration...

  2. 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...

  3. 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

  4. Understanding sea level changes

    OpenAIRE

    Chao, BF; Farr, T.; Labrecque, J; Bindschadler, R.; Douglas, B; E. Rignot; Shum, CK; Wahr, J.

    2002-01-01

    Sea level change occurs on all timescales, depending on the type of change in question. It also occurs with a continuous range of spatial scales-local, regional, and global. To understand and be able to eventually predict sea level changes is a truly interdisciplinary endeavor. It requires geodetic and non-geodetic measurements of various types from space as well as in situ, while various numerical models for a number of meteorological and geophysical processes or properties are essential or ...

  5. Canterbury Basin Sea Level

    OpenAIRE

    Fulthorpe, C. S.; Institute for Geophysics John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin J.J. Pickle Research Campus, Building 196 (ROC) 10100 Burnet Road (R2200) Austin TX 78758-4445 USA; Hoyanagi, K.; Department of Geology Faculty of Science Shinshu University 3-1-1 Asahi, Matsumoto 390-8621 Japan; Blum, P.; United States Implementing Organization Integrated Ocean Drilling Program Texas A&M University 1000 Discovery Drive College Station TX 77845 USA; Guèrin, G.; Borehole Research Group Lamont-Doherty Earth Observatory of Columbia University PO Box 1000, 61 Route 9W Palisades NY 10964 USA; Slagle, A. L.; Borehole Research Group Lamont-Doherty Earth Observatory of Columbia University PO Box 1000, 61 Route 9W Palisades NY 10964 USA; Blair, S. A.; Department of Geological Sciences Florida State University 006 Carraway Building Tallahassee FL 32306 USA; Browne, G. H.; Hydrocarbon Section GNS Science PO Box 30368 Lower Hutt New Zealand; Carter, R. M.; Marine Geophysical Laboratory James Cook University of North Queensland Townsville QLD 4811 Australia; Ciobanu, M.; Laboratoire de Microbiologie des Environnements Extrêmes CNRS UMR-6197 Institut Universitaire Européen de la Mer Technopole Brest-Iroise Plouzane 29280 France; Claypool, G. E.; Organic Geochemist 8910 West 2nd Avenue Lakewood CO 80226 USA; Crundwell, M. P.; New Zealand Observer/Paleontologist (foraminifers) Paleontology and Environmental Change Section GNS Science PO Box 30368 Lower Hutt New Zealand; Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Ding, X.; School of Marine Sciences China University of Geosciences (Beijing) 29 XueYuan Road, Haidian District Beijing P.R. China; George, S. C.; Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia; Hepp, D. A.; MARUM – Center for Marine Environmental Sciences and Department of Geosciences University of Bremen Leobener Strasse MARUM Building, Room 2230 28359 Bremen Germany

    2010-01-01

    Integrated Ocean Drilling Program (IODP) Expedition 317 was devoted to understanding the relative importance of global sea level (eustasy) versus local tectonic and sedimentary processes in controlling continental margin sedimentary cycles. The expedition recovered sediments from the Eocene to recent period, with a particular focus on the sequence stratigraphy of the late Miocene to recent, when global sea level change was dominated by glacioeustasy. Drilling in the Canterbury Basin,...

  6. Ventilation of the Mediterranean Sea constrained by multiple transient tracer measurements

    Directory of Open Access Journals (Sweden)

    T. Stöven

    2013-10-01

    Full Text Available Ventilation is the prime pathway for ocean surface perturbations, such as temperature anomalies, to be relayed to the ocean interior. It is also the conduit for gas exchange between atmosphere and ocean and thus the mechanism whereby, for instance, the interior ocean is oxygenated and enriched in anthropogenic carbon. The ventilation of the Mediterranean Sea is fast in comparison to the world ocean and has large temporal variability, so that quantification of Mediterranean Sea ventilation rates is challenging and very relevant for Mediterranean oceanography and biogeochemistry. Here we present transient tracer data from a field-campaign in April 2011 that sampled a unique suite of transient tracers (SF6, CFC-12, tritium and 3He in all major basins of the Mediterranean. We apply the Transit Time Distribution (TTD model to the data which then constrain the mean age, the ratio of the advective/diffusive transport mechanism, and the presence, or not, of more than one significant (for ventilation water mass. We find that the eastern part of the Eastern Mediterranean can be reasonable described with a one dimensional Inverse Gaussian (1IG TTD, and thus constrained with two independent tracers. The ventilation of the Ionian Sea and the Western Mediterranean can only be constrained by a multidimensional TTD. We approximate the ventilation with a two-dimensional Inverse Gaussian (2IG TTD for these areas and demonstrate one way of constraining a 2IG-TTD from the available transient tracer data. The deep water in the Ionian Sea has higher mean ages than the deep water of the Levantine Basin despite higher transient tracer concentrations. This is partly due to the deep water of Adriatic origin having more diffusive properties in the transport and formation, i.e. a high ratio of diffusion over advection, compared to the deep water of Aegean Sea origin that still dominates the deep Levantine Basin deep water after the Eastern Mediterranean Transient (EMT in

  7. EMODNet Hydrography - Seabed Mapping - Developing a higher resolution digital bathymetry for the European seas

    Science.gov (United States)

    Schaap, Dick M. A.; Moussat, Eric

    2013-04-01

    In December 2007 the European Parliament and Council adopted the Marine Strategy Framework Directive (MSFD) which aims to achieve environmentally healthy marine waters by 2020. This Directive includes an initiative for an overarching European Marine Observation and Data Network (EMODNet). The EMODNet Hydrography - Seabed Mapping projects made good progress in developing the EMODNet Hydrography portal to provide overview and access to available bathymetric survey datasets and to generate an harmonised digital bathymetry for Europe's sea basins. Up till end 2012 more than 8400 bathymetric survey datasets, managed by 14 data centres from 9 countries and originated from 118 institutes, have been gathered and populated in the EMODNet Hydrography Data Discovery and Access service, adopting SeaDataNet standards. These datasets have been used as input for analysing and generating the EMODNet digital terrain model (DTM), so far for the following sea basins: • the Greater North Sea, including the Kattegat • the English Channel and Celtic Seas • Western and Central Mediterranean Sea and Ionian Sea • Bay of Biscay, Iberian coast and North-East Atlantic • Adriatic SeaAegean - Levantine Sea (Eastern Mediterranean). • Azores - Madeira EEZ The Hydrography Viewing service gives users wide functionality for viewing and downloading the EMODNet digital bathymetry: • water depth in gridded form on a DTM grid of a quarter a minute of longitude and latitude • option to view QC parameters of individual DTM cells and references to source data • option to download DTM tiles in different formats: ESRI ASCII, XYZ, CSV, NetCDF (CF), GeoTiff and SD for Fledermaus 3 D viewer software • option for users to create their Personal Layer and to upload multibeam survey ASCII datasets for automatic processing into personal DTMs following the EMODNet standards The NetCDF (CF) DTM files are fit for use in a special 3D Viewer software package which is based on the existing open

  8. 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.

  9. 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

  10. Lost at Sea

    Institute of Scientific and Technical Information of China (English)

    Maya; Reid

    2011-01-01

    OVER the last several years,dozens of sea turtles have been washing up on the shores of Central Africa dead.Many of these creatures,olive ridley turtles,were adult females poised to breed. Most puzzling,though,is that these turtles are being found on protected beaches that belong to national parks both in Gabon and the Republic of the Congo. Olive ridleys are considered to be the most abundant sea turtles on the planet,with around 800,000 females nesting annually.They can be found around the globe,in places like China’s Hainan and Hong Kong,among others.In spite of their numbers,they are the world’s most exploited species of sea

  11. Indicators and SEA

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    well as in communicative perspective. Developing indicators is both a political and professional process, and the paper finally discuss the need of selection criteria mentioned in the guidelines, and also gives some ideas on how to tackle the development of indicators being explicit about it both as a......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...

  12. 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.

  13. Sea-level fluctuations and deep-sea sedimentation rates.

    Science.gov (United States)

    Worsley, T R; Davies, T A

    1979-02-01

    Sediment accumulation rate curves from 95 drilled cores from the Pacific basin and sea-level curves derived from continental margin seismic stratigraphy show that high biogenous sediment accumulation rates correspond to low eustatic sea levels for at least the last 48 million years. This relationship fits a simple model of high sea levels producing lower land/sea ratios and hence slower chemical erosion of the continents, and vice versa. PMID:17734144

  14. Skin disorders at sea.

    Science.gov (United States)

    Lucas, Ray; Boniface, Keith; Hite, Michael

    2010-01-01

    The purpose of this study is to characterize the types of skin disorders occurring at sea requiring acute treatment. The case logs of a tele-medicine service for US flagged ships at sea were reviewed from March 1, 2006 until March 1, 2009. Of 1844 total cases, 10% (n = 183) were for skin disorders. Sixty-eight percent (n = 125) were infections, 14% (n = 25) were inflammatory, 7% (n = 13) were environmental, and 11% (n = 20) were non-specific rashes. Cutaneous abscesses and cellulitis (n = 84) were the most common acute skin disorders encountered. In some cases (n = 81), still digital photographs aided in the diagnosis. PMID:20496321

  15. 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.

  16. 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...

  17. Exposure of the population of countries within the European Union to radioactivity in the mediterranean sea: Project MARINA-MED

    International Nuclear Information System (INIS)

    The discharges examined in the Project MARINA-MED were from nuclear installations in France, Italy and Spain, over the period 1980-1991; those from the Marcoule fuel reprocessing plant were found to contribute most of the collective dose arising from radioactivity in the Mediterranean Sea. Over 90% of beta-gamma discharges were of tritium and the remainder comprised some 80% 106Ru + 106Rh, 7% 90Sr + 90Y, 6% 137Cs, and 1% each of 134Cs, 58Co and 54Mn. The alpha emitters were dominated by 241Am, 239+240Pu and natural uranium, each representing 30% of the total. The contribution from Chernobyl had largely disappeared by 1990, except in the northern Aegean Sea, where continuing input came from the Black Sea. The corresponding exposure of the critical group in the Mediterranean Sea area from 137Cs (for an annual consumption of 73 kg fish and 35 kg shellfish) was estimated to be 7.5 μSv in 1990; the exposure of the critical group in the Black Sea area would have been about 40 μSv. These values are much lower than that estimated for 210Po, which corresponds to about 0.5 mSv. Data were obtained on catches and consumption rates of fish, crustaceans and molluscs for the relevant countries within the European Union, including import and export. Using data from the Food and Agriculture Organization of the United Nations, it was possible to extend the data to other countries bordering the Mediterranean Sea. Peak annual collective doses were estimated at less than 0.2 man·Sv for the period considered. For discharges over the entire period (1980-1991) the total collective dose commitment, truncated at 500 years, was estimated to be about 2 man·Sv. The most significant radionuclides, especially in the first few years, were found to be 106Ru (0.76 man·Sv) and 241Am (0.25 man·Sv). (author). 7 refs, 3 tabs

  18. 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…

  19. The Dirac Sea

    OpenAIRE

    Dimock, J.

    2010-01-01

    We give an alternate definition of the free Dirac field featuring an explicit construction of the Dirac sea. The treatment employs a semi-infinite wedge product of Hilbert spaces. We also show that the construction is equivalent to the standard Fock space construction.

  20. 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)

  1. The Provident Sea

    Science.gov (United States)

    Cushing, David H.

    1988-09-01

    The Provident Sea describes the history of fish stock management (including whales and seals). The book traces, on the basis of the original scientific material, the history of the management of "the provident sea" up to recent times when problems of over-exploitation have had dramatic effects upon stocks. The need for management arose mainly from the increasing industrialization of capture. Hence the preindustrial fisheries are covered, in particular the old cod fishery on the Grand Bank and the herring fishery in the North Sea, as an essential background to current problems. The origins of fisheries and whaling science are described, as is the development up to 1965 of the science and institution in fisheries, whaling, and sealing. In the sixties and seventies, certain major fishing nations took a heavy harvest of fish stocks using sophisticated and efficient gathering methods. This in turn led to conflict and one consequence was the "Law of the Sea" conference set up to try and resolve these issues.

  2. 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/

  3. 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...

  4. The Sea Beside Us

    Science.gov (United States)

    Watling, Carol; Hallard Raymond E.

    1974-01-01

    The Sea Beside Us for the Special Child is a project in Delaware with three goals: providing outdoor and overnight experiences for handicapped children; introducing these students to beach, bay, and marsh environments; and increasing the number of special education teachers incorporating seashore studies in their teaching curriculum. (LS)

  5. Modelling of the anthropogenic tritium transient and its decay product helium-3 in the Mediterranean Sea using a high-resolution regional model

    Science.gov (United States)

    Ayache, M.; Dutay, J.-C.; Jean-Baptiste, P.; Beranger, K.; Arsouze, T.; Beuvier, J.; Palmieri, J.; Le-vu, B.; Roether, W.

    2015-05-01

    This numerical study provides the first simulation of the anthropogenic tritium invasion and its decay product helium-3 (3He) in the Mediterranean Sea. The simulation covers the entire tritium (3H) transient generated by the atmospheric nuclear weapons tests performed in the 1950s and early 1960s and is run till 2011. Tritium, helium-3 and their derived age estimates are particularly suitable for studying intermediate and deep-water ventilation and spreading of water masses at intermediate/deep levels. The simulation is made using a high-resolution regional model NEMO (Nucleus for European Modelling of the Ocean), in a regional configuration for the Mediterranean Sea called MED12, forced at the surface with prescribed tritium evolution derived from observations. The simulation is compared to measurements of tritium and helium-3 performed along large-scale transects in the Mediterranean Sea during the last few decades on cruises of R/V Meteor: M5/6, M31/1, M44/4, M51/2, M84/3, and R/V Poseidon: 234. The results show that the input function used for the tritium generates a realistic distribution of the main hydrographic features of the Mediterranean Sea circulation. In the eastern basin, the results highlight the weak formation of Adriatic Deep Water in the model, which explains its weak contribution to the Eastern Mediterranean Deep Water (EMDW) in the Ionian sub-basin. It produces a realistic representation of the Eastern Mediterranean Transient (EMT) signal, simulating a deep-water formation in the Aegean sub-basin at the beginning of 1993, with a realistic timing of deep-water renewal in the eastern basin.

  6. Sea-Level Projections from the SeaRISE Initiative

    Science.gov (United States)

    Nowicki, Sophie; Bindschadler, Robert

    2011-01-01

    SeaRISE (Sea-level Response to Ice Sheet Evolution) is a community organized modeling effort, whose goal is to inform the fifth IPCC of the potential sea-level contribution from the Greenland and Antarctic ice sheets in the 21st and 22nd century. SeaRISE seeks to determine the most likely ice sheet response to imposed climatic forcing by initializing an ensemble of models with common datasets and applying the same forcing to each model. Sensitivity experiments were designed to quantify the sea-level rise associated with a change in: 1) surface mass balance, 2) basal lubrication, and 3) ocean induced basal melt. The range of responses, resulting from the multi-model approach, is interpreted as a proxy of uncertainty in our sea-level projections. http://websrv.cs .umt.edu/isis/index.php/SeaRISE_Assessment.

  7. The sea is your mirror

    OpenAIRE

    Parenthoen, Marc; Murie, Fred; Thery, Flavien

    2015-01-01

    The Sea Is Your Mirror is an artistic interactive experience where surface cerebral electromagnetic waves from a participant wearing an EEG sensor headset are depicted in real-time as ocean waves in an animated 3D environment. The aim of this article is to describe the sea wave model used for the sea state animation and how it is connected to the brain computer interface (BCI). The sea state is animated by the groupy choppy wave model that provides nonlinear sea states with wave groups and as...

  8. Dead Sea Rate of Evaporation

    OpenAIRE

    Abdelaziz L. AL-Khlaifat

    2008-01-01

    The Dead Sea is exceptional by many standards. It is the saltiest and lowest lake in the world. Moreover it is a closed lake with very large variations in its water level caused by both man-made and natural oscillations of the components that make up the water balance. Most of the fundamental studies on the Dead Sea focused on the sea water contents, Dead Sea geology, salt origin, ground-water sea intrusion, and qualitative analysis of the material balance. The objective of the present paper ...

  9. Climate variability in the Eastern and Western Mediterranean Sea over the last two millennia: a contribution of PaleoMex/MISTRALS

    Science.gov (United States)

    Gogou, Alexandra; Sicre, Marie-Alexandrine; Triantaphyllou, Maria; Parinos, Konstantine; Bouloubassi, Ioanna; Dimiza, Margarita; Rousakis, Grigoris; Korres, Gerasimos; Kallel, Nejib; Jalali, Bassem; Kaberi, Helen; Ezat, Ullah; Lykousis, Vasilios

    2013-04-01

    Recent compilations of Mediterranean 2k paleoclimate archives (Luterbacher et al., 2012, MedClivar Book) stressed the lack of high-resolution/ continuous marine records. The two new high-resolution sea surface temperature (SSTs) time-series presented here from the shallow coastal shelf sediments of the Gulf of Lions and deeper ocean one of the Aegean Sea using alkenone paleothermometry, are thus an important contribution. SST values are roughly 2°C warmer in the Eastern than Western Mediterranean sites in agreement with our knowledge of the production pattern of the main alkenone producer Emiliania huxleyi in the two basins. Both SST-record reveal significant variability of cool/warm intervals, corresponding to the continental European and Northern Hemisphere climatic variability. While distant from each other, SSTs at the two sites show some degree of similarity: increasing SSTs from ~ 600 to 1300 AD followed by a significant cooling till the early 1600's marking the onset of an outstanding warm period reaching values similar to present day. After a sharp decrease ending around 1700 yrs AD, the last three centuries indicate gradually rising SSTs by about 1°C/100 yrs. To our knowledge the latter feature has been undocumented in North Atlantic cores but often observed in paleoclimate reconstructions of the European climate, though with different regional timing and amplitude. This unexpected finding may reflect feedbacks from the surrounding land-masses contributing to "continentalize" the Mediterranean climate. Another notable feature is the short-lived abrupt cooling in the Aegean record between 1816 and 1824 yr AD, possibly expressing the surface water cooling subsequent to the Tambora volcanic eruption of 1815 yrs AD. * We acknowledge financial support from MEDECOS (Marin-ERA, EU/FP6) Project and the Greek General Secretary of Research and Technology. Luterbacher J, Garcia-Herrera R, Allan R, Alvarez-Castro BG, Benito G, Booth J, Büntgen U, Colombaroli D

  10. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    Aerosols are important climactically. Their specific emissions are key to reducing the uncertainty in global climate models. Marine aerosols make up the largest source of primary aerosols to the Earth's atmosphere. Uncertainty in marine aerosol mass and number flux lies in separating primary...... 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...

  11. Changing Sea Levels

    Science.gov (United States)

    Pugh, David

    2004-04-01

    Flooding of coastal communities is one of the major causes of environmental disasters world-wide. This textbook explains how sea levels are affected by astronomical tides, weather effects, ocean circulation and climate trends. Based on courses taught by the author in the U.K. and the U.S., it is aimed at undergraduate students at all levels, with non-basic mathematics being confined to Appendices and a website http://publishing.cambridge.org/resources/0521532183/.

  12. Wood decay at sea

    Science.gov (United States)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  13. Sea-Level climate variability in the Mediterranean Sea

    OpenAIRE

    Bonaduce, Antonio

    2012-01-01

    Sea-level variability is characterized by multiple interacting factors described in the Fourth Assessment Report (Bindoff et al., 2007) of the Intergovernmental Panel on Climate Change (IPCC) that act over wide spectra of temporal and spatial scales. In Church et al. (2010) sea-level variability and changes are defined as manifestations of climate variability and change. The European Environmental Agency (EEA) defines sea level as one of most important indicators for monitoring climate chan...

  14. Characterization of aerosol episodes in the greater Mediterranean Sea area from satellite observations (2000-2007)

    Science.gov (United States)

    Gkikas, A.; Hatzianastassiou, N.; Mihalopoulos, N.; Torres, O.

    2016-03-01

    An algorithm able to identify and characterize episodes of different aerosol types above sea surfaces of the greater Mediterranean basin (GMB), including the Black Sea and the Atlantic Ocean off the coasts of Iberia and northwest Africa, is presented in this study. Based on this algorithm, five types of intense (strong and extreme) aerosol episodes in the GMB are identified and characterized using daily aerosol optical properties from satellite measurements, namely MODIS-Terra, Earth Probe (EP)-TOMS and OMI-Aura. These aerosol episodes are: (i) biomass-burning/urban-industrial (BU), (ii) desert dust (DD), (iii) dust/sea-salt (DSS), (iv) mixed (MX) and (v) undetermined (UN). The identification and characterization is made with our algorithm using a variety of aerosol properties, namely aerosol optical depth (AOD), Ångström exponent (α), fine fraction (FF), effective radius (reff) and Aerosol Index (AI). During the study period (2000-2007), the most frequent aerosol episodes are DD, observed primarily in the western and central Mediterranean Sea, and off the northern African coasts, 7 times/year for strong episodes and 4 times/year for extreme ones, on average. The DD episodes yield 40% of all types of strong aerosol episodes in the study region, while they account for 71.5% of all extreme episodes. The frequency of occurrence of strong episodes exhibits specific geographical patterns, for example the BU are mostly observed along the coasts of southern Europe and off the Atlantic coasts of Portugal, the MX episodes off the Spanish Mediterranean coast and over the Adriatic and northern Aegean Sea, while the DSS ones over the western and central Mediterranean Sea. On the other hand, the extreme episodes for all but DD aerosol display more patchy spatial patterns. The strong episodes exhibit AOD at 550 nm as high as 1.6 in the southernmost parts of central and eastern Mediterranean Sea, which rise up to 5 for the extreme, mainly DD and DSS, episodes. Although more

  15. Sea level monitoring in Mozambique

    OpenAIRE

    Nhampulo, C.I.S.; Ruby, J,

    2002-01-01

    Observing changes in the rise of relative sea level has resulted from the balance between the sea level rise due to the global warming of the planet, and the vertical displacements of the coast due to geological movements. The main objective of this paper is to outsource information about sea level monitoring in Mozambique, as part of a common global effort aiming to colect and analyse data that can help in understanding physical processes envolving ocean basins or oceans as a hole. Tidal ...

  16. Air sea ratio reduction initiative

    Energy Technology Data Exchange (ETDEWEB)

    Oberle, Jean

    2010-09-15

    Airfreight is the most expensive mode of transportation as well as the most impacting in terms of CO{sup 2} emissions. It is 7 times more expensive on average to ship by air than shipping by sea 1. Airfreight transportation mode emits 30 times more CO{sup 2} than sea freight mode 2. These elements provided a compelling platform to design a global logistics program to initiate a modal shift from air to sea freight without compromising service to customers.

  17. Sea Otter, River Otter. The Wonder Series.

    Science.gov (United States)

    Robinson, Sandra Chisholm

    This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The…

  18. Japan nuclear ship sea trial

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Hiroshi; Kitamura, Toshikatus; Mizushima, Toshihiko [Japan Atomic Energy Research Inst., Mutsu, Aomori (Japan). Mutsu Establishment] [and others

    1992-01-01

    The sea trial of the first Japan nuclear Ship `MUTSU` was conducted from the end of October to December in 1990. The purpose of the sea trial was to verify the nuclear propulsive performances and maneuverabilities. The present report describes the results of the sea trial. These results are classified into four items: 1. Speed test and engineering performance tests 2. Maneuvering performance tests 3. Vibration tests 4. Other tests. Acceptable performances were demonstrated, as expected in the original design. The experience of the use of the Global Positioning System (GPS), which were newly adopted for the sea trial, is also reported. (author).

  19. Japan nuclear ship sea trial

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Hiroshi; Kitamura, Toshikatus; Mizushima, Toshihiko (Japan Atomic Energy Research Inst., Mutsu, Aomori (Japan). Mutsu Establishment) (and others)

    1992-01-01

    The sea trial of the first Japan nuclear Ship 'MUTSU' was conducted from the end of October to December in 1990. The purpose of the sea trial was to verify the nuclear propulsive performances and maneuverabilities. The present report describes the results of the sea trial. These results are classified into four items: 1. Speed test and engineering performance tests 2. Maneuvering performance tests 3. Vibration tests 4. Other tests. Acceptable performances were demonstrated, as expected in the original design. The experience of the use of the Global Positioning System (GPS), which were newly adopted for the sea trial, is also reported. (author).

  20. Japan nuclear ship sea trial

    International Nuclear Information System (INIS)

    The sea trial of the first Japan nuclear Ship 'MUTSU' was conducted from the end of October to December in 1990. The purpose of the sea trial was to verify the nuclear propulsive performances and maneuverabilities. The present report describes the results of the sea trial. These results are classified into four items: 1. Speed test and engineering performance tests 2. Maneuvering performance tests 3. Vibration tests 4. Other tests. Acceptable performances were demonstrated, as expected in the original design. The experience of the use of the Global Positioning System (GPS), which were newly adopted for the sea trial, is also reported. (author)

  1. AIR / SEA RESCUE LAUNCHES

    Directory of Open Access Journals (Sweden)

    W.H. Rice

    2012-02-01

    Full Text Available The Motor Boat Wing of the South African Air Force was inaugurated some thirty eight years ago.With its main base at Gordon's Bay, the wing was formed to operate the various marine craft used to provide a service to the flying component of the South African Air Force. Its main function was to be air/sea rescue, but it also had to man and maintain armoured target boats, seaplane tenders, marine tenders and the 'bomb scows', used for recovering practise bombs and missiles and for laying and lifting moorings.

  2. Deep-sea fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Damare, S.

    • Institut fur Biotechno\\ogle. Biotechnikum. Walter Rathenau Strasse 49A, 17489GrcJf~wald.Germany. 265 266 Raghukumar and Damare from water samples collected from the subtropical Atlantic Ocean, from the surface to a depth of 4,500 m using sterile van Dom... Calcareous shells %5, Bay ofBengal 73 Only preserved specimens CFU CFt.: Chapter IS • Deep-Sea Fungi 267 fungi were isolated from surface-sterilized calcareous fragments collected from a depth of 300 to 860 m in the Bay of Bengal (73). These fungi were...

  3. Sea shore in Cyprus

    OpenAIRE

    2016-01-01

    Black and white photograph, showing a winter’s day at a deserted sea shore in Cyprus - Μαυρόασπρη κάρτ ποστάλ που απεικονίζει μια χειμωνιάτικη μέρα σε μια ερημική ακτή στην Κύπρο.

  4. The Sea Around Us

    Science.gov (United States)

    Carson, Rachel L.

    1991-12-01

    Published in 1951, The Sea Around Us is one of the most remarkably successful books ever written about the natural world. Rachel Carson's rare ability to combine scientific insight with moving, poetic prose catapulted her book to first place on The New York Times best-seller list, where it enjoyed wide attention for thirty-one consecutive weeks. It remained on the list for more than a year and a half and ultimately sold well over a million copies, has been translated into 28 languages, inspired an Academy Award-winning documentary, and won both the 1952 National Book Award and the John Burroughs Medal. This classic work remains as fresh today as when it first appeared. Carson's writing teems with stunning, memorable images--the newly formed Earth cooling beneath an endlessly overcast sky; the centuries of nonstop rain that created the oceans; giant squids battling sperm whales hundreds of fathoms below the surface; and incredibly powerful tides moving 100 billion tons of water daily in the Bay of Fundy. Quite simply, she captures the mystery and allure of the ocean with a compelling blend of imagination and expertise. Reintroducing a classic work to a whole new generation of readers, this Special Edition features a new chapter written by Jeffrey Levinton, a leading expert in marine ecology, that brings the scientific side of The Sea Around Us completely up to date. Levinton incorporates the most recent thinking on continental drift, coral reefs, the spread of the ocean floor, the deterioration of the oceans, mass extinction of sea life, and many other topics. In addition, acclaimed nature writer Ann Zwinger has contributed a brief foreword. Today, with the oceans endangered by the dumping of medical waste and ecological disasters such as the Exxon oil spill in Alaska, this illuminating volume provides a timely reminder of both the fragility and the importance of the ocean and the life that abounds within it. Anyone who loves the sea, or who is concerned about our

  5. Two Sea-Level Challenges

    Science.gov (United States)

    Galvin, C.

    2008-12-01

    "No place on the sandy ocean shores of the world has been shown to be eroding because of sea level rise." This statement appeared nearly 19 years ago in bold print at the top of the page in a brief article published in Shore and Beach (Galvin,1990). The term "sea level rise" was defined in 1990 as follows: "In this statement, "sea level rise" has the meaning that the average person on the street usually attaches to that term. That is, sea level is rising; not, as in some places like the Mississippi River delta, land level is sinking." While still a subject of controversy, it is now (2008) increasingly plausible (Tornqvist et al,2008) that damage from Hurricane Katrina was significantly worse on the Mississippi River delta because floodwaters exploited wetlands and levees whose elevations had been lowered by decades of compaction in the underlying soil. (1) "Sea level" commonly appears in the literature as "relative sea level rise", occurring that way in 711 publications between 1980 and 2009 (GeoRef database on 8 Sep 08). "Relative sea level rise" does not appear in the 2005 AGI Glossary. The nearest Glossary term is "relative change in sea level", but that term occurs in only 12 publications between 1980 and 2009. The Glossary defines this term in a sequence stratigraphy sense, which infers that "relative sea level rise" is the sum of bottom subsidence and eustatic sea level rise. In plain English, "relative sea level rise" means "water depth increase". For present day coastal environments, "relative sea level rise" is commonly used where eustatic sea level rise is less than subsidence, that is, where the magnitude of actual sea level rise is smaller than the magnitude of subsidence. In that situation, "relative sea level rise" misleads both the average person and the scientist who is not a coastal geologist. Thus, the first challenge is to abandon "relative sea level rise" in favor of "water depth increase", in order that the words accurately descibe what happens

  6. Deep sea biophysics

    International Nuclear Information System (INIS)

    A collection of deep-sea bacterial cultures was completed. Procedures were instituted to shelter the culture collection from accidential warming. A substantial data base on the rates of reproduction of more than 100 strains of bacteria from that collection was obtained from experiments and the analysis of that data was begun. The data on the rates of reproduction were obtained under conditions of temperature and pressure found in the deep sea. The experiments were facilitated by inexpensively fabricated pressure vessels, by the streamlining of the methods for the study of kinetics at high pressures, and by computer-assisted methods. A polybarothermostat was used to study the growth of bacteria along temperature gradients at eight distinct pressures. This device should allow for the study of microbial processes in the temperature field simulating the environment around buried HLW. It is small enough to allow placement in a radiation field in future studies. A flow fluorocytometer was fabricated. This device will be used to determine the DNA content per cell in bacteria grown in laboratory culture and in microorganisms in samples from the ocean. The technique will be tested for its rapidity in determining the concentration of cells (standing stock of microorganisms) in samples from the ocean

  7. Sea ice terminology

    Energy Technology Data Exchange (ETDEWEB)

    1980-09-01

    A group of definitions of terms related to sea ice is presented, as well as a graphic representation of late winter ice zonation of the Beaufort Sea Coast. Terms included in the definition list are belt, bergy bit, bight, brash ice, calving, close pack ice, compacting, compact pack ice, concentration, consolidated pack ice, crack, diffuse ice edge, fast ice, fast-ice boundary, fast-ice edge, first-year ice, flaw, flaw lead, floe, flooded ice, fractured, fractured zone, fracturing, glacier, grey ice, grey-white ice, growler, hummock, iceberg, iceberg tongue, ice blink, ice boundary, ice cake, ice edge, ice foot, ice free, ice island, ice shelf, large fracture, lead, medium fracture, multiyear ice, nilas, old ice, open pack ice, open water, pack ice, polar ice, polynya, puddle, rafted ice, rafting, ram, ridge, rotten ice, second-year ice, shearing, shore lead, shore polynya, small fracture, strip, tabular berg, thaw holes, very close pack ice, very open pack ice, water sky, young coastal ice, and young ice.

  8. 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...

  9. Neutrino sea scope takes shape

    Science.gov (United States)

    Cartlidge, Edwin

    2016-03-01

    A consortium of European physicists building a vast neutrino detector on the floor of the Mediterranean Sea has unveiled the science it will carry out. The Cubic Kilometre Neutrino Telescope (KM3NeT) will use strings of radiation detectors arranged in a 3D network to measure the light emitted when neutrinos very occasionally interact with the surrounding sea water.

  10. 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 of...

  11. Governance of the Wadden Sea

    NARCIS (Netherlands)

    Slob, Adriaan F.L.; Geerdink, T.R.A.; Rockmann, Christine; Vöge, S.

    2016-01-01

    The Wadden Sea is a unique area from ecological, geological and cultural perspectives and lies in the territories of Denmark, Germany and the Netherlands. The trilateral cooperation on the protection of the Wadden Sea can be marked to start in 1978, although the countries already cooperated befor

  12. The Sea Trout Year 1985

    OpenAIRE

    Fahy, E

    1986-01-01

    The wet year of 1985 yielded good catches to the rod and to commercial engines. Salmon were taken in reasonable numbers in the drift nets although only small numbers of sea trout were captured by this method. The wet angling season is thought to have provided productive fishing conditions contributing largely to a 22% increase over the previous year's landings of sea trout.

  13. Pollution of the North Sea

    International Nuclear Information System (INIS)

    This is the first modern review on the fate, distribution and effects of pollutants in the North Sea. The reader will find general information on the North Sea system and details on the behavior of pollutants and their impact on selected areas and organisms. (orig.) With 238 figs

  14. 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 discussed, with

  15. 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

  16. FLOATING CRANE RESPONSE IN SEA WAVES

    OpenAIRE

    Čorić, Većeslav; Ćatipović, Ivan; Slapničar, Vedran

    2014-01-01

    Many activities present in the offshore technology are affected by sea waves and their safety strongly depends on the sea state. The fundamental question in operation risk analysis is the limit sea state which enables the safe operation controlled in all phases: from the sea surface to the sea bottom. The safe limit sea state is especially important when some lifting operation is performed in sea waves. This paper presents a dynamical model of a floating crane in sea waves with a hanging load...

  17. Uranium from sea water

    International Nuclear Information System (INIS)

    The prevalent situation in the field of uranium extraction from the oceans was reviewed from a scientific and technological standpoint and as to legality too. No international convention seems to limit the access to dissolved or suspended matter in free area of the oceans. All publications received through 1979 point to adsorption as the method of choice, at some form of hydrated titanium ''oxide'' as the most promising sorbent, and, generally spoken, at the cost of pumping water through the contacting system as a huge economical problem. A recent Swedish invention may circumvent the pumping problem by making available, in a previously unknown manner, some kind of self-renewing energy from the oceans. A simple economic calculus has resulted in costs from two to six times the present world market price of crude uranium oxide (which is assumed to be US dollar 43.-/1b), with a possibility to compete really after some technical and systematic developments. Results from a small-scale adsorption experiment in genuine sea water are presented: During a few weeks sea water was pumped through tiny, 10 cm high beds of sodium titanate ion exchangers, partly in the hydrogen form. The grain size was 250-500 μm, the flow rate 0.15-0.61 m/min. About 5% of the total amount of uranium passing the columns was retained, resulting in 8-11 μg/Ug. Also, large amounts of manganese, strontium, vanadium and zink were retained. Some of these elements and plankton as well may perhaps be recovered with an economic gain

  18. 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.

  19. Rapid sea-level rise

    Science.gov (United States)

    Cronin, Thomas M.

    2012-11-01

    Several global and regional factors contribute to observed sea-level change along any particular coast. Global processes include changes in ocean mass (glacio-eustasy from ice melt), ocean volume (steric effects), viscoelastic land movements (glacioisostatic adjustment GIA), and changes in terrestrial water storage. Regional processes, often connected to steric and glacial changes, include changes in ocean circulation (Meridional Overturning Circulation [MOC]), glacial melting, local GIA, regional subsidence and others. Paleoclimate, instrumental and modeling studies show that combinations of these factors can cause relatively rapid rates of sea-level rise exceeding 3 mm yr-1 over various timescales along particular coasts. This paper discusses patterns and causes of sea-level rise with emphasis on paleoclimatological records. It then addresses the hypothesis of late Holocene (pre-20th century) sea-level stability in light of paleoclimatic evidence, notably from reconstructions of sea-surface temperature and glacial activity, for significant climate and sea-level variability during this time. The practical difficulties of assessing regional sea-level (SL) patterns at submillennial timescales will be discussed using an example from the eastern United States.

  20. The Kerr-Fermi Sea

    CERN Document Server

    Hartman, Thomas; Strominger, Andrew

    2009-01-01

    The presence of a massive scalar field near a Kerr black hole is known to produce instabilities associated with bound superradiant modes. In this paper we show that for massive fermions, rather than inducing an instability, the bound superradiant modes condense and form a Fermi sea which extends well outside the ergosphere. The shape of this Fermi sea in phase space and various other properties are analytically computed in the semiclassical WKB approximation. The low energy effective theory near the black hole is described by ripples in the Fermi surface. Expressions are derived for their dispersion relation and the effective force on particles which venture into the sea.

  1. Towards Good Order at Sea

    DEFF Research Database (Denmark)

    Mandrup, Thomas; Vreÿ, Francois

    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. 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 in...

  2. Advantages of North Sea Assets

    International Nuclear Information System (INIS)

    The North Sea is a significant hydrocarbon province and any large multinational will need to maintain North Sea assets within their portfolio - as indeed they do. The general feeling that pervades the oil industry that the North Sea is ''mature'' can be demonstrated by reference to the facts. The result is a potential fall-off in activity and a serious threat to the future levels of profitability in the region. Notwithstanding the continuing development of large fields, such as Troll, of or multi-field developments, for example BP's recent announcement on ETAPs, activity is beginning to fall, most noticeably at the front end of the development cycle, in exploration. (author)

  3. 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.

  4. AoA Region: South Asian Seas

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    The South Asian Seas region lies in the northern extreme of the Indian Ocean. It includes the Arabian Sea and Bay of Bengal Large Marine Ecosystems (LME) along with their marginal basins as well as the Laccadive Sea and the Andaman Sea. Counties...

  5. Baltic sea level low-frequency variability

    OpenAIRE

    Kulikov, Evgueni A.; Medvedev, Igor P.; Koltermann, Klaus Peter

    2015-01-01

    The low-frequency sea level spectrum in the Baltic Sea has been analysed based on long-term time series of sea level data (15–124 yr) from three tide gauge stations in the Baltic Sea and two stations in the North Sea. The principal periodicities detected in the spectrum are seasonal and tidal oscillations including the pole tide with a period of about 14 months. Cross-spectral analysis has been applied to estimate the frequency response of sea level oscillations in the Baltic Sea relative to ...

  6. Euthanasia across the North Sea

    OpenAIRE

    Rigter, Henk; Borst-Eilers, Els; Leenen, H J J

    1988-01-01

    The United Kingdom and The Netherlands are separated by a narrow stretch of sea but in terms of an understanding of euthanasia they seem to be light years apart. An attempt to bridge the information gap seems in order.

  7. The Maastrichtian sea level rise

    OpenAIRE

    Gullentops, F.

    1986-01-01

    The maximum sea level rise during the Maastrichtian has been much less than the 500 m claimed by some recent authors on this subject. Sedimentological and geomorphological arguments against such an hypothesis are forwarded.

  8. 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...

  9. ROE Absolute Sea Level Changes

    Data.gov (United States)

    U.S. Environmental Protection Agency — This raster dataset represents changes in absolute sea level along U.S. coasts from 1993 to 2014. Data were provided by the University of Colorado at Boulder (2015)...

  10. 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)

  11. Sea Turtle Cold Stun Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This spreadsheet includes data on sea turtle cold stun strandings from 2001 to present. These data include field number, species, stranding date, turtle...

  12. 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...... ARC 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...

  13. Sea Level Threat in Tuvalu

    Directory of Open Access Journals (Sweden)

    Than Aung

    2009-01-01

    Full Text Available Problem statement: Recently the impacts of climate change, in particular, sea level rise, had been a major concern for many Pacific island countries. In early 2000, there were a series of media coverage over sea level rise issues using Tuvalu as an example. The daily life of Tuvalu revolves around the ocean and the immediate threat on the islands people, economy, environment and its islands is of concern to the Tuvalu government. The Tuvalu government has concluded that Tuvalu was destined to become the first nation to be sunk by global warming because it is one of the smallest and lowest-lying countries in the world. Approach: In this study, sea level data from the Australian project will be focussed on despite the fact that the length of data is not sufficiently long. The AusAID funded South Pacific Sea Level and climate monitoring project was set up in response to concerns raised by Pacific island countries over the potential impacts of an enhanced greenhouse effect on climate and sea levels in the South Pacific for 20 years. Results: Based upon the 15½ years of sea level data from the project, the sea level rise rate in Tuvalu as at september 2008 was 5.9 mM year-1. This was about four times higher than the global average of 1-2 mm year-1. Sea level in the Tuvalu area had risen approximately 9.14 cm since the inception of the project 15½ years ago. However, it was to be noted that the land is quite stable and the rate of land sinking is -0.06 mM year-1 only. Accordingly, there was no significant impact on the sea level trends. Conclusion: Although the data length is just over 15 years, the sea level trend values do not fluctuate significantly since 1999. It simply indicated that the rate of sea level rise in the Tuvalu region was not accelerating as anticipated by the community.

  14. Sea Level Threat in Tuvalu

    OpenAIRE

    Than Aung; Awnesh Singh; Uma Prasad

    2009-01-01

    Problem statement: Recently the impacts of climate change, in particular, sea level rise, had been a major concern for many Pacific island countries. In early 2000, there were a series of media coverage over sea level rise issues using Tuvalu as an example. The daily life of Tuvalu revolves around the ocean and the immediate threat on the islands people, economy, environment and its islands is of concern to the Tuvalu government. The Tuvalu government has concluded that Tuvalu was destined to...

  15. Respiration in Neonate Sea Turtles

    OpenAIRE

    Price, Edwin R.; Paladino, Frank V.; Strohl, Kingman P.; Pilar Santidrián, T.; Klann, Kenneth; Spotila, James R.

    2006-01-01

    The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings’ response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ...

  16. Studies on sea snake venom

    OpenAIRE

    TAMIYA, Nobuo; YAGI, Tatsuhiko

    2011-01-01

    Erabutoxins a and b are neurotoxins isolated from venom of a sea snake Laticauda semifasciata (erabu-umihebi). Amino acid sequences of the toxins indicated that the toxins are members of a superfamily consisting of short and long neurotoxins and cytotoxins found in sea snakes and terrestrial snakes. The short neurotoxins to which erabutoxins belong act by blocking the nicotinic acetylcholine receptor on the post synaptic membrane in a manner similar to that of curare. X-ray crystallography an...

  17. Bioactive molecules from sea hares.

    Science.gov (United States)

    Kamiya, H; Sakai, R; Jimbo, M

    2006-01-01

    Sea hares, belonging to the order Opisthobranchia, subclass Gastropoda, are mollusks that have attracted many researchers who are interested in the chemical defense mechanisms of these soft and "shell-less" snails. Numbers of small molecules of dietary origin have been isolated from sea hares and some have ecologically relevant activities, such as fish deterrent activity or toxicity. Recently, however, greater attention has been paid to biomedically interesting sea hare isolates such as dolastatins, a series of antitumor peptide/macrolides isolated from Dolabella auricularia. Another series of bioactive peptide/macrolides, as represented by aplyronines, have been isolated from sea hares in Japanese waters. Although earlier studies indicated the potent antitumor activity of aplyronines, their clinical development has never been conducted because of the minute amount of compound available from the natural source. Recent synthetic studies, however, have made it possible to prepare these compounds and analogs for a structure-activity relationship study, and started to uncover their unique action mechanism towards their putative targets, microfilaments. Here, recent findings of small antitumor molecules isolated from Japanese sea hares are reviewed. Sea hares are also known to produce cytotoxic and antimicrobial proteins. In contrast to the small molecules of dietary origin, proteins are the genetic products of sea hares and they are likely to have some primary physiological functions in addition to ecological roles in the sea hare. Based on the biochemical properties and phylogenetic analysis of these proteins, we propose that they belong to one family of molecule, the "Aplysianin A family," although their molecular weights are apparently divided into two groups. Interestingly, the active principles in Aplysia species and Dolabella auricularia were shown to be L-amino acid oxidase (LAAO), a flavin enzyme that oxidizes an alpha-amino group of the substrate with

  18. Artificial radioactivity in the North Sea

    International Nuclear Information System (INIS)

    The question of radioactive contamination of the environment is a problem of world-wide importance. The North Sea is an important example of a sea region heavily used by man and therefore polluted by different contaminants including radionuclides. A review of the present knowledge of the radiological situation of the North Sea and adjacent sea regions is given. The sources of artificial radionuclides and their distribution, behaviour and fate in this shallow sea area are discussed. (author)

  19. Evaporation of Boric Acid from Sea Water

    OpenAIRE

    Gast, James A.; Thompson, Thomas G.

    2011-01-01

    Previous investigators have shown that the boron-chlorinity ratios of rain waters are many times greater than the boron-chlorinity ratio of sea water. The presence of boron in the atmosphere has been attributed to sea spray, volcanic activity, accumulation in dust, evaporation from plants, and industrial pollution. In this paper data are presented to demonstrate that boric acid in sea water has a vapor pressure at ordinary temperatures of the sea and, when sea water evaporates, boric acid occ...

  20. Intermittent sea-level acceleration

    Science.gov (United States)

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  1. DESERVE - Dead Sea Research Venue

    Science.gov (United States)

    Mohsen, A.; Weber, M. H.; Kottmeier, C.

    2013-12-01

    DESERVE 'Dead Sea Research Venue' focuses on the Dead Sea region as it is a unique environment and may be considered as one of the most inspiring natural laboratories on Earth. The Dead Sea Region is an exceptional ecosystem whose seismic activity has influenced all facets of the development, from ground water availability to human evolution. DESERVE addresses three grand challenges: Environmental Risks, Water Availability, Climate Change and comprises long term monitoring of geophysical parameters, studies of coupled processes in the atmosphere, hydrosphere and lithosphere as well as modeling of prediction and remediation strategies of geogenic risks. The Dead Sea has been selected for this integrated approach because it constitutes an outstanding 'natural laboratory' to study these phenomena, as - all 3 challenges are critical in this region. - the region is especially sensitive to climate change and human influences such as ground and surface water over-exploitation for agriculture and industrial purposes. - environmental processes are subject to boundary conditions that cannot be found elsewhere on Earth - understanding their interactions and the future evolution of the whole Dead Sea region are of key importance for economic development in peaceful cooperation. Results obtained in the Dead Sea region are also of prototype relevance for other (semi)-arid terminal basins of the world.

  2. 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...

  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

    2016-04-01

    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. 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...

  5. Variability In The Solomon Sea From Altimetric Sea Level Data

    Science.gov (United States)

    Melet, A.; Gourdeau, L.; Kessler, W.; Verron, J.

    2007-12-01

    In the southwest tropical Pacific, subtropical waters from the SEC flow in the Solomon Sea, mainly through the western boundary New Guinea Coastal Undercurrent, and join the equatorial western Pacific by three narrow straits. The NGCU transports part of the spiciness anomalies generated in the South East Pacific and subducted in the thermocline. Because the NGCU is a primary source of the EUC, variations of its characteristics are expected to play a role in the equatorial thermocline features and more generally on decadal climate variability. Therefore, the study of the Solomon Sea is a key issue of the SPICE program. In this study, we focus on the variability of the Solomon Sea in term of sea level. The Solomon Sea is semi closed with a complex topography and numerous islands. Thus, the use of classical gridded altimetric products is inadequate. Consequently, this work is based on original along track Topex/Poseidon data. New data processing (CTOH/LEGOS) has been applied to recover proper data and to gain more information on the altimetric signal in this region. A track-by-track specific and customized post processing has been used to finalize the dataset. These new altimetric data have been assessed against tide gauge data. The analysis of the resulting sea level anomalies exhibits the highest variability observed in the tropical Pacific in an area centred near 8°S and expanding from each side of the Solomon Islands, outside of the WBC. Sea level variability presents a wide temporal spectrum, from intraseasonal to interannual ranges with the notable influence of the monsoon and of ENSO. In the Solomon Sea, three frequencies emerge : 60, 365 and 2000 days. The 60-days frequency seems particularly important in the Solomon Sea compared with the surrounding waters and an EOF analysis is used to understand its features. We also depict the signature of the New Guinea Coastal Current (NGCC), the western boundary current flowing north along the eastern coast of Papua

  6. Sea level pressure climatology in black sea region

    Directory of Open Access Journals (Sweden)

    Sayed Mohammad Hosseini

    2014-02-01

    Full Text Available In the present study, to achieve a comprehensive view of pressure conditions in the Black Sea region, sea level pressure data in Reanalysis II database in National Centers for Environmental Prediction (NCEP/National Center for Atmospheric Research (NCAR were used. The data temporal resolution is daily and the spatial resolution is 2.5×2.5 degrees of arc. The investigated framework covers the areas between -30-70 degrees east longitude and 20-70 degrees north latitude and has dimensions equal 41×21 pixels consisting of 861 pixels. The studied period of time is 33-year (1979 to 2012 and includes 12419 days and 861 spatial pixels. Therefore, sea level pressure data matrix is 12419×861, which has 12419 temporal pixels and 861 spatial ones. In other words, the arrangement of the data is S-shaped. The rows of the matrix represent time while columns represent space. At the end, using the cluster analysis, six sea level pressure circulation patterns based on the spatial - temporal features were obtained: Red Sea trough is fall pattern; Iraq trough is spring pattern; Persian Gulf trough is transitional pattern; Persian Gulf deep trough is summer pattern; Caucasian high pressure is fall - winter pattern and the Caucasian Strong high pressure is winter pattern. In most of these patterns, intensive allobaric conditions can be observed in the troughs and ridges.

  7. 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.

  8. SeaWinds - Greenland

    Science.gov (United States)

    1999-01-01

    The frequent coverage provided by NASA's SeaWinds instrument on the QuikScat satellite provides unprecedented capability to monitor daily and seasonal changes in the key melt zones of Greenland, which is covered with a thick ice sheet that resulted from snow accumulating over tens of thousands of years. The thickness of the snow layers reveals details about the past global climate, and comparing snow accumulation and snow melting can provide insight into climate change and global warming. In particular, the extent of summer melting of snow in Greenland is considered a sensitive indicator of global change.Earlier scatterometer data has suggested that Greenland has experienced significantly more melting in recent years. This figure compares the melting observed over 15 days during July 1999 in Greenland. The red areas around the central blue and white areas are the main melt zones and have lower radar back scatter because of water on the surface that saturates the surface snow. As the days warm up, the melt extent dramatically increases. Comparing this data with computer models and past scatterometer data will help scientists evaluate the inter-annual variability of the melting as a step toward understanding potential climate change.The world's large ice sheets in Greenland and Antarctica act as vast storehouses of freshwater. Summer season melting releases large quantities of freshwater into the ocean, and year-to-year variations can have a significant impact on global sea level. Furthermore, long-term changes in the patterns and extent of melting on the large ice sheets reflect the effects of climate variability; thus Greenland is considered a sensitive indicator of global warming.Satellite microwave radars are extremely sensitive to melting and can provide the only effective means of accurately measuring the year-round picture of the extent and variability in ice sheet melting. Daily mean images were produced from QuikScat data collected over the Greenland ice

  9. 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.

  10. 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.)

  11. 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.

  12. High resolution sea floor bathymetry using high frequency multibeam sonar and structured light laser imaging

    Science.gov (United States)

    Roman, C.; Inglis, G.; Smart, C.; Vaughn, I.; Carey, S.

    2011-12-01

    Detailed bathymetric maps of the sea floor with centimeter level resolution can be produced by underwater vehicles using multibeam sonars and structured light laser imaging. Over spatial scales up to tens of thousands of square meters it is possible to produce maps gridded to sub centimeter levels. This level of accuracy demands detailed treatments of the sensor relative data, the vehicle navigation data and the vehicle to sensor position and rotational offsets. The presented results will show comparisons between these two sensor modalities. Data have a been collected during recent field programs to the Kolumbo volcanic crater and the Southern Aegean Sea. Our data processing and map making technique is based on the Simultaneous Localization and Mapping (SLAM) concept, which is an active research area in both the marine and land robotics communities. The SLAM method provides a common framework for addressing both sensor and navigation errors in a self consistent manner. Using automated patch registration and filter techniques both the multibeam and laser data can be processed by the same algorithm. Structured light imaging has been a common machine vision technique for 3D shape estimation in industrial applications, but has had limited use underwater. By using a camera to image a projected laser line on the sea floor it is possible to determine the 3D profile of the bottom with sub centimeter resolution. Sequential images taken during a survey can be processed and merged into a bathymetric map in a similar manner as individual multibeam sonar pings. The resulting maps can be gridded down to 2.5 millimeter resolution and clearly show objects just a few centimeters in size. The structured light data have been compared to multibeam sonar data taken with BlueView Technologies sonars operating at both 1375 kHz and 2250 kHz. Such high frequency sonars offer centimeter resolution over ranges to 30 and 10 meters respectively. The difference between the broader footprint

  13. 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.

  14. 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.

  15. 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.

  16. Monitoring sea level and sea surface temperature trends from ERS satellites

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Knudsen, Per; Beckley, B.

    2002-01-01

    radiometer (AV-HRR) sea surface temperature observations. Global averaged spatial correlations between the 50degrees parallels are 0.87 between the ATSR and AVHRR based sea surface temperature trends-values, and 0.85 between the UP and ERS altimetric sea level trends. The spatial correlation between the ERS......Data from the two ESA satellites ERS-1 and ERS-2 are used in global and regional analysis of sea level and sea surface temperature trends over the last, 7.8 years. T he ERS satellites and in the future the ENVISAT satellite provide unique opportunity for monitoring both changes in sea level and sea...... surface temperature as these satellites are equipped with an altimeter to measure sea level height as well as an along track scanning radiometer (ATSR) to measure the sea surface temperature. Consistent increase in both sea level and sea surface temperatures are found in most parts of the Atlantic Ocean...

  17. Oil and the Caspian Sea

    International Nuclear Information System (INIS)

    Caspian Sea is the biggest lake in the world. It is almost F-shape and located between five Countries of Iran, Turkmenistan, Russia, Azarbayjohn, Ghazaghestan. Un fortunately, in the different region of the sea there are highly contaminated oil, in addition with other source of pollutants such as: agricultural, industrial and domestic pollution, which causes to eliminate the natural habitats of aquatic life and thus, the Caspian sea with all of the valuable natural sources of foods and energy is close to be destroyed. This paper studies the pollution by oil industry which causes the elimination of aquatic life and natural ecosystem, as well as, necessary plan to over come the present situation

  18. Radioactivity in the North Sea

    International Nuclear Information System (INIS)

    This chapter lists the main sources of radioactivity in the North Sea and explains the units used. The main source is naturally occuring long-lived radionuclides. Other significant sources are the Sellafield reprocessing plant, atmospheric atomic weapons testing, fallout from the Chernobyl reactor accident, the French nuclear reprocessing plant at Cap la Hague and oilfield production water brines. However, currently these are not significant compared with the natural background. If this is to continue, lower levels of discharge into the sea, strict control of new discharges and the cessation of atmospheric nuclear tests will be needed. There is a map showing the concentration of Cs137 in filtered water from the North Sea in 1985. (UK)

  19. 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...

  20. Assimilation of sea surface temperature, sea ice concentration and sea ice drift in a model of the Southern Ocean

    OpenAIRE

    Barth, Alexander; Canter, Martin; Van Schaeybroeck, Bert; Vannitsem, Stéphane; Massonnet, François; Zunz, Violette; Mathiot, Pierre; Alvera Azcarate, Aïda; Beckers, Jean-Marie

    2015-01-01

    Current ocean models have relatively large errors and biases in the Southern Ocean. The aim of this study is to provide a reanalysis from 1985 to 2006 assimilating sea surface temperature, sea ice concentration and sea ice drift. In the following it is also shown how surface winds in the Southern Ocean can be improved using sea ice drift estimated from infrared radiometers. Such satellite observations are available since the late seventies and have the potential to improve the wind forcing be...

  1. Fluctuation of dominant mesozooplankton species in the Black Sea, North Sea and the Baltic Sea: Is a general trend recognisable?

    OpenAIRE

    NIERMANN, Ulrich; BİNGEL, Ferit; ERGÜN, Güner

    1998-01-01

    The distribution and fluctation of dominant pelagic species>300µ(Copepoda, Chaetognatha, Scyhozoa, Ctenophora and ichthyoplankton) of the southern Black Sea were compared with that of dominant species of the North Sea and the Baltic Sea in relation to oceanographic and environmental features. In all three seas, similar changes in the zooplankton composition took place at the end of the 1980's, and the beginning of the 1990's. - decreasing or increasing abundances of certain s...

  2. Climate change challenges for SEA

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen

    This paper takes a theoretical perspective on the challenges that climate changes pose for SEA. The theoretical framework used is the sociologist Ulrich Beck’s theory of risk society and the aspects that characterise this society. Climate change is viewed as a risk, and the theory is used to derive...... two challenges for the practice of SEA: delivering assessments and predictions; and handling differences in opinion and debate. Based on empirical evidence from document studies and interviews, the paper discusses the reflection of these theoretical challenges in practice....

  3. 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

  4. 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’

  5. 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...

  6. 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...

  7. 16 MW under the seas

    International Nuclear Information System (INIS)

    This article presents the Nemo project (Nemo stands for New Energy for Martinique and Overseas) and its precursor project, Ner 300, developed in cooperation between Akuo Energy and DCNS, and which is financed by the European Bank for Investment. These projects aim at exploiting sea thermal energy. Ner 300 will exploit the 20 degree difference between surface waters (25 C) and deep waters (5 C at 1.000 m under sea level). The article evokes works performed by DCNS to develop a prototype near the Reunion Island. The principle and operation are briefly described, and technological challenges are outlined

  8. 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.

  9. 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...

  10. OW NASA SeaWIFS Ocean Color

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface ocean color (chlorophyll-a) measurements collected by means of the Sea-viewing Wide Field-of-view Sensor...

  11. Global and Regional Sea Level Change

    OpenAIRE

    Wenzel, Manfred; Schröter, Jens

    2012-01-01

    Sea level variations prior to the launch of satellite altimeters are estimated by analysing historic tide gauge records. Recently, a number of groups have reconstructed sea level by applying EOF techniques to gappy data. We complement this study with alternativemethods. In a first step gaps in 178 records of sea level change are filled using the pattern recognition capabilities of artificial neural networks. Afterwards satellite altimetry is used to extrapolate local sea level change to globa...

  12. Global Warming and Caspian Sea Level Fluctuations

    OpenAIRE

    Ardakanian, Reza; Alemohammad, Seyed Hamed

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea level is high and als...

  13. A survey of European sea level infrastructure

    OpenAIRE

    Woodworth, P. L.; Rickards, L. J.; Pérez, B

    2009-01-01

    This paper summaries findings from a survey of European sea level infrastructure (tide gauges, telemetry methods, ancillary information) conducted at the end of 2008 on behalf of the Tsunami Risk ANd Strategies For the European Region (TRANSFER), Tsunami Early Warning and Mitigation System in the North-Eastern Atlantic, the Mediterranean and Connected Seas (NEAMTWS), European Sea Level Service (ESEAS) and Global Sea Level Observing System (GLOSS) projects and programmes. Approximately 478 str...

  14. Characteristics of Environment in Yatsushiro Sea

    OpenAIRE

    Takikawa, Kiyoshi; Aoyama, Chiharu; TANAKA Kenji; Morimoto, Kentaro; Watanabe, Kaname; タキカワ, キヨシ; アオヤマ, チハル; タナカ, ケンジ; モリモト, ケンタロウ; ワタナベ, カナメ; 滝川, 清; 青山, 千春; 田中, 健路; 森本, 剣太郎

    2005-01-01

    The Yatsushiro Sea has serious environmental problems similar to those affecting the Ariake Sea. In this study we performed a causal analysis of environmental change in the Yatsushiro Sea by investigating environmental characteristics such as water quality and atmospheric phenomena over the past 26 years. Numerical experiments yielded the following results: 1) there exist 5 distinct environmental domains within the Yatsushiro Sea, 2) during summer, density layers develop over the entire Yatsu...

  15. 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...

  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, dril

  17. OIL POLLUTION OF THE BLACK SEA

    Directory of Open Access Journals (Sweden)

    Georgiy Biliavskiy

    2012-09-01

    Full Text Available  Article is devoted to meaningfulness estimation of some factors in forming ecological conditions in regions of the Black Sea. Comparative estimation of anthropogenic contamination degree of sea regions environment considered. The zons the most unhappy in ecological attitude are defined, that allows to mark first and foremost arrangements on improvement of ecological situation of the Black Sea.

  18. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    hurricane generates seas by Young (1998, 2003, and 2006), requiring maximum wind speeds, forward velocity and radius to maximum wind speed. An averaged radius to maximum sustained wind speeds, according to Hsu et al. (1998) and averaged forward speed of cyclonic storms are applied in the initial state. In a...

  19. The sea urchin immune system

    Directory of Open Access Journals (Sweden)

    LC Smith

    2006-05-01

    Full Text Available Metchnikoff’s use of sea star larvae to observe encapsulation and phagocytosis, which was followedmuch later by allograft rejection kinetics, revealed that echinoderms had an innate immune system thatwas lacking of adaptive attributes. Larval sea urchins mount defenses in response to contact withmicrobes, which are mediated by phagocytic blastocoelar cells and pigment cells. In the adult, thecoelomocytes mediate immune responses through phagocytosis and encapsulation of foreign particles inaddition to degranulation of antimicrobial molecules. Molecular analysis of immune functions in the seaurchin has demonstrated a complement system that appears to have multiple alternative pathways andseveral activators of the lectin pathway, but may be missing the terminal pathway. Other genes andproteins involved in the sea urchin immunity include expanded sets of lectins, proteins with scavengerreceptor cysteine-rich repeats, Toll-like receptors and associated signalling proteins. A vast array ofproteins belonging to the 185/333 family are expressed in coelomocytes in response to lipopolysaccharideand show a surprising level of diversity. The sea urchin innate immune system has a number of largegene families with unexpected complexities and elevated levels of diversification.

  20. The Sea Ice Board Game

    Science.gov (United States)

    Bertram, Kathryn Berry

    2008-01-01

    The National Science Foundation-funded Arctic Climate Modeling Program (ACMP) provides "curriculum resource-based professional development" materials that combine current science information with practical classroom instruction embedded with "best practice" techniques for teaching science to diverse students. The Sea Ice Board Game, described…

  1. Killer storms from the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    The author has discussed the distruction taking place due to cyclone in the Indian subcontinent of formation which is said to be the result of thermal fronts in the atmosphere and sea interaction of different air masses is discussed in detailed...

  2. Past and present Aral Sea

    Science.gov (United States)

    Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek

    2013-04-01

    The tragedy of disappearing of Aral Sea is well known to the World. Before and after collapse of Soviet Union, a huge quantity of scientific and popular editions described with grief the situation around the Aral Sea. After the NIS states became independent, World Bank, UNDP, UNEP in proper competition with each other had provided some assessment of the situation through presentation of some small and medium grants, but after 2000, the local population remained alone with own problems. Although on the eyes of the present generation a unique transformation of great water body into deserts took place, the global scientific community did not find forces and financing for real and detail investigation of the processes accompanying the Sea shrinking and land formation. We should acknowledge and give big respect to NATO, later to German Government that through GTZ (now GIZ) - German International Collaboration Agency - and GFZ (Potzdam) paid attention to this area of environment crisis and organized scientific and protective design in the so-called Priaralie - the territory around the drying Sea and delta of the two rivers - Amudarya and Syrdarya. Thank to this assistance, the local specialists in collaboration with limited a number of foreign scientists (N.Aladin, P.Zavialov, Joop de Schutter, Hans Wilps, Hedi Oberhansli) organized significant works for detail socioeconomic, ecological and hydrological assessment situation in Priaralie and on the Aral sea coast. On this base, Ministry of Agriculture and Water resources of Uzbekistan and State Committee of Water resources of Kazakhstan developed a plan of rehabilitation of Amudarya and Syrdarya deltas and started implementation of these projects. If Kazakh water authority moved ahead in wetland restoration faster, a forestation of delta and drying bed of Aral Sea got big success in Uzbek territory. 244 thousands hectares of saxsaul and tamarix were planted for protection of the Priaralie. By request of GTZ SIC, ICWC

  3. Management of the Wadden Sea

    Science.gov (United States)

    Wolff, W. J.; Zijlstra, J. J.

    1980-03-01

    The Wadden Sea situated along the North Sea coasts of Denmark, the Federal Republic of Germany and The Netherlands represents one of the world's largest bar-built type of estuaries. The area is a typical sedimentation and mineralization basin, with a large influx of organic matter from the adjoining North Sea, consequently a delicate oxygen balance and a rich benthic macrofauna, poor in species, which serves as food for juveniles of some commercially important North Sea fishes and for large numbers of migrating and wintering waders and waterfowl. Past and present activities of the human society in the area include fisheries (mainly for shrimp and mussels, semi-culture), shipping, land reclamation, recreation, dredging for sand and shells, and waste discharge from industries and human communities. Until the present these activities, although sometimes conflicting, did not fundamentally affect the area and its biota (pollution excluded), but future claims, including the construction of large deep-sea harbours, drilling for natural gas and oil, large-scale land reclamation and increased industrialization etc., might gradually induce degradation. For instance, area reduction by continued land reclamation could lead to irreversible losses of specific biotopes (e. g. salt-marshes, mud-flats), which could affect the size of bird and fish populations in a much wider region. Increased pollution, which has already inflicted damage on bird and seal populations, could reduce the fauna and hence the value of the area as a natural sanctuary. In the event of a proposal for a new human activity in the area, the present standing practice in the countries concerned requires an evaluation of its safety and economic aspects and its environmental impact. However, the various plans are considered separately and there is a general need for integrated management of the area.

  4. Sea ice variability and trends in the Weddell Sea for 1979-2006

    OpenAIRE

    Schwegmann, Sandra; Timmermann, Ralph; Gerdes, Rüdiger; Lemke, Peter

    2012-01-01

    Sea ice concentration in the Weddell Sea is subject to regional climate variability. The magnitude and origin of local trends in the sea ice coverage were studied using the bootstrap algorithm sea ice concentration data from the NSIDC for 1979-2006. The impact of atmospheric forcing such as air temperature, wind speed, and cloud coverage, gained from NCEP/NCAR reanalysis, on sea ice was assessed by analyzing correlation coefficients between the respective atmospheric component and the satelli...

  5. Sea-level variability in the Caribbean Sea over the last century

    OpenAIRE

    Torres Parra, R. Ricardo

    2013-01-01

    Mean sea level rise exposes coasts to increasing risks. For the Caribbean Sea, the regional and local sea-level behaviour is not well known. This study has investigated the sea level behavior in the region at different frequencies during the last century, to provide updated, accurate and useful information to implement coastal adaptation responses to sea-level hazards. Time series from 28 tide-gauges, 18 years of altimetry and various atmospheric and oceanographic climatologies have been used...

  6. Distribution characteristics of marine litter on the sea bed of the East China Sea and the South Sea of Korea

    Science.gov (United States)

    Lee, Dae-In; Cho, Hyeon-Seo; Jeong, Sun-Beom

    2006-10-01

    The types, quantities, and distribution of marine litter found on the sea bed of the East China Sea and the South Sea of Korea are surveyed. Surveys were evaluated using bottom trawl nets during 1996-2005 cruises. Mean distribution densities were high in coastal seas, especially in the South Sea of Korea offshore from Yeosu, with 109.8 kg km -2, and low in the East China Sea, with densities of 30.6 kg km -2. Fishing gear, such as pots, nets, octopus jars, and fishing lines, accounted for about 42-72% and 37-62% of litter items in the East China Sea and the South Sea of Korea, respectively, whereas the contributions of rubber, vinyl, metal, plastic, glass, wood, and clothing were below 30% mainly. Rope and drum composition fluctuated greatly, between 54% and 0%. Eel and net pots dominated the marine debris of the South Sea of Korea, and some vinyl, plastics, and fishing gear made in Korea, China, and Japan were collected in abundance in the East China Sea. Fishing gear was probably discarded into the sea, deliberately or inadvertently, by fishing operations. A comprehensive joint approach by Korea, China, and Japan is needed for the continuous monitoring of input sources, the actual conditions, and the behavior of marine litter for protection against litter pollution and fisheries resource management in this area.

  7. Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

  8. Evaluation of the sea ice proxy IP25 against observational and diatom proxy data in the SW Labrador Sea

    DEFF Research Database (Denmark)

    Weckstrom, Kaarina; Masse, Guillaume; Collins, Lewis G.; Hanhijarvi, Sami; Bouloubassi, Ioanna; Sicre, Marie-Alexandrine; Seidenkrantz, Marit-Solveig; Schmidt, Sabine; Andersen, Thorbjorn J.; Andersen, Morten L.; Hill, Brian; Kuijpers, Antoon

    , identified in marine sediments underlying seasonal sea ice, has emerged as a potential sea ice specific proxy for past sea ice cover. We tested the reliability of this biomarker as a sea ice proxy against observational sea ice data (sea ice concentrations from the global HadISST1 database) and against a more...

  9. Seasonal variability in the Baltic Sea level

    OpenAIRE

    Marek Świrgoń; Małgorzata Stramska; Halina Kowalewska-Kalkowska

    2013-01-01

    Sea level is subject to spatial and temporal variability on different scales. In this paper we investigate seasonal variability in the open Baltic Sea level using daily satellite altimetry data for the period 1 January 1993-31 December 2010. Our results indicate that there is a well-pronounced seasonal cycle in the 18-year average sea level and in its standard deviation. The average annual SLA amplitude in the open Baltic Sea is about 18 cm. The seasonal cycle of the SLA in the Baltic Sea is ...

  10. Regional Variability in Sea Level Rise

    OpenAIRE

    Meyssignac, Benoit

    2012-01-01

    Over the XXth century, tide gauge records indicate a rise in global sea level of 1.7 mm.a-1. For the past two decades, satellite altimetry data indicate a faster sea level rise of 3.2 mm.a-1 (period 1993-2011). Thanks to its global coverage, they also reveal a strong regional variability in sea level rise that is several times bigger than the global rise in many regions of the world. This regional signal, which must be added to the global sea level rise to compute the total sea level signal, ...

  11. Global Warming and Caspian Sea Level Fluctuations

    CERN Document Server

    Ardakanian, Reza

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea level is high and also positive and almost the same for all the stations. But the yearly correlation was negative. It means that the sea level has decreased by the increase in temperature.

  12. Clearing of the sea bed in the North Sea 1993

    International Nuclear Information System (INIS)

    The report relates to an NPD (Norwegian Petroleum Directorate) project which aimed to clear away objects from the sea bed on the Norwegian continental shelf. The project was divided in two phases. Phase 1 included the recording of objects by the use of sonars, and phase 2 covered the clearing operation itself. The results from the project, which included a fishery-intensive and oil-related area of 1300 km2 on Egersundbanken, are presented. 3 figs., 4 tabs

  13. Sea ice density estimation in the Bohai Sea using the hyperspectral remote sensing technology

    Science.gov (United States)

    Liu, Chengyu; Shao, Honglan; Xie, Feng; Wang, Jianyu

    2014-11-01

    Sea ice density is one of the significant physical properties of sea ice and the input parameters in the estimation of the engineering mechanical strength and aerodynamic drag coefficients; also it is an important indicator of the ice age. The sea ice in the Bohai Sea is a solid, liquid and gas-phase mixture composed of pure ice, brine pockets and bubbles, the density of which is mainly affected by the amount of brine pockets and bubbles. The more the contained brine pockets, the greater the sea ice density; the more the contained bubbles, the smaller the sea ice density. The reflectance spectrum in 350~2500 nm and density of sea ice of different thickness and ages were measured in the Liaodong Bay of the Bohai Sea during the glacial maximum in the winter of 2012-2013. According to the measured sea ice density and reflectance spectrum, the characteristic bands that can reflect the sea ice density variation were found, and the sea ice density spectrum index (SIDSI) of the sea ice in the Bohai Sea was constructed. The inversion model of sea ice density in the Bohai Sea which refers to the layer from surface to the depth of penetration by the light was proposed at last. The sea ice density in the Bohai Sea was estimated using the proposed model from Hyperion image which is a hyperspectral image. The results show that the error of the sea ice density inversion model is about 0.0004 g•cm-3. The sea ice density can be estimated through hyperspectral remote sensing images, which provide the data support to the related marine science research and application.

  14. Catfish - King of the sea

    OpenAIRE

    Godø, Olav Rune; Huse, Irene; Michalsen, Kathrine

    1995-01-01

    During an acoustic tagging experiment on cod in the Barents Sea in March 1995 a hierarchy between different fish species was revealed, and the catfish (Anarhichas sp.) was observed to be dominant in relation to cod and haddock. When catfish are present at the fishing grounds, the dominant feeding behaviour of this species might reduce efficiency on other species. If longline catch data are used for stock assessment purposes, the catfish population might therefore be overestimat...

  15. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO4) and the alpha zirconium hydrogen phosphate (Zr(HPO4) 2H2O) starting from sea sand in an easy and economic way. (Author)

  16. Ploughing the deep sea floor

    OpenAIRE

    Puig, Pere; Canals, Miquel; Company, Joan B.; Martín, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert; Calafat, Antoni M.

    2012-01-01

    Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations1, 2 and benthic communities3, 4 has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes5, 6. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and ...

  17. Chemical munitions dumped at sea

    Science.gov (United States)

    Edwards, Margo; Bełdowski, Jacek

    2016-06-01

    Modern chemical warfare is a byproduct of the industrial revolution, which created factories capable of rapidly producing artillery shells that could be filled with toxic chemicals such as chlorine, phosgene and mustard agent. The trench warfare of World War I inaugurated extensive deployments of modern chemical weapons in 1915. Concomitantly, the need arose to dispose of damaged, captured or excess chemical munitions and their constituents. Whereas today chemical warfare agents (CWA) are destroyed via chemical neutralization processes or high-temperature incineration in tandem with environmental monitoring, in the early to middle 20th century the options for CWA disposal were limited to open-air burning, burial and disposal at sea. The latter option was identified as the least likely of the three to impact mankind, and sea dumping of chemical munitions commenced. Eventually, the potential impacts of sea dumping human waste were recognized, and in 1972 an international treaty, the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, was developed to protect the marine environment from pollution caused by the dumping of wastes and other matter into the ocean. By the time this treaty, referred to as the London Convention, was signed by a majority of nations, millions of tons of munitions were known to have been disposed throughout the world's oceans.

  18. MODIS Global Sea Surface Temperature

    Science.gov (United States)

    2002-01-01

    Every day the Moderate-resolution Imaging Spectroradiometer (MODIS) measures sea surface temperature over the entire globe with high accuracy. This false-color image shows a one-month composite for May 2001. Red and yellow indicates warmer temperatures, green is an intermediate value, while blues and then purples are progressively colder values. The new MODIS sea surface temperature product will be particularly useful in studies of temperature anomalies, such as El Nino, as well as research into how air-sea interactions drive changes in weather and climate patterns. In the high resolution image, notice the amazing detail in some of the regional current patterns. For instance, notice the cold water currents that move from Antarctica northward along South America's west coast. These cold, deep waters upwell along an equatorial swath around and to the west of the Galapagos Islands. Note the warm, wide currents of the Gulf Stream moving up the United States' east coast, carrying Caribbean warmth toward Newfoundland and across the Atlantic toward Western Europe. Note the warm tongue of water extending from Africa's east coast to well south of the Cape of Good Hope. MODIS was launched in December 1999 aboard NASA's Terra satellite. For more details on this and other MODIS data products, please see NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami

  19. Sedimentation rate in Ariake Sea

    International Nuclear Information System (INIS)

    The Ariake Sea is a shallow and almost enclosed sea located in western Kyushu, Japan with an area of about 1,700 km2 and the deepest up to 30 m at north area. The most inner part of the bay area is very shallow and during low tide big mudflats tideland appears and extends up to several km. The tidal range is the highest in Japan with a maximum of about 6 m. The area is one of Japan's most important area for fishery, with over 40% of the total seaweed production in Japan In the year 2001, due to environmental conditions, the seaweed population decreased substantially with a production drop of about 50%. This was caused by an earlier winter outbreak of red tide that affected the seaweed quality. One proposed cause for this decline might be the land reclamation project in the western part of Ariake Sea, Isahaya Bay. This project started in April 1997 were more than 3,000 ha of the bay where closed by a 7 km long seawall. Contaminated water is regularly discharged from the reservoir inside the dike, which have resulted in changes in water flows and perhaps a decrease in tidal range. In 2002, the gates at the dike were open for two months for a survey campaign and the seaweed harvest in the winter 2002-2003 was quite good. However, the problem may be linked to totally different causes, e.g. increase in industrial pollution discharge, chemicals used in the disinfection methods of washing seaweed, or change in water pH after the volcanic eruptions of the Unzen mountain in 1992 and 1993. The purpose of the research is to elucidate present condition of the Ariake Sea and past history using by radiometric methods, and obtained useful information will resolve the environmental status of Ariake Sea and give us answers way to save the Ariake Sea. Sea sediment cores were taken on board in 2003 at several points covering the Ariake sea. Two cores taken in inner area of the sea were sectioned at every 2 cm intervals and subjected to gamma spectrometry to determine sedimentation

  20. Radioactivity in the Arctic Seas. Report for the International Arctic Seas Assessment Project (IASAP)

    International Nuclear Information System (INIS)

    This report provides comprehensive information on environmental conditions in the Arctic Seas as required for the study of possible radiological consequences from dumped high level radioactive wastes in the Kara Sea. The report describes the oceanography of the regions, with emphasis on the Kara and Barents Seas, including the East Novaya Zemlya Fjords. The ecological description concentrates on biological production, marine food-weds and fisheries in the Arctic Seas. The report presents data on radionuclide concentrations in the Kara and Barents Seas and uses these data to estimate the inventories of radionuclides currently in the marine environment of the Kara and Barents Seas

  1. Mean depth sea simulation using radioactive tracers

    International Nuclear Information System (INIS)

    On the basis of investigations carried out at the Department of Physics of the Vilnius Engineering Construction Institute the problem of mean depth sea simulation is studied using radioactive tracers. The rapid method of radiocesium concentration measurement in sea water is advanced. Radiocesium is adsorbed from 80-100 l of sea water within an 1.2-1.5 hour interval. The mean values of Cs-137 and Sr-90 concentrations for the three depths at different seasons in the Baltic Sea during.the period of 1973-1978 fluctuated within the limits of 0.43-1.3 pCi/l, and in the North Sea during the period of 1974-1977 - 0.81-4.0 pCi/l and 0.51-0.71 pCi/l, respectively. Periodical variations of the concentration of both nuclides in the Baltic Sea and continuous increase of the radiocesium concentration in the North Sea are noted. The results of calculation of the Cs-137 concentrations in the surface waters of the Baltic Sea by objective analysis are presented, the results obtained are discussed. A short calculation method of the vector field of the velocities and directions of the Baltic Sea currents is given, as well as the results of the calculations. An anomalous depth distribution of the concentration of both radionuclides in circulation places is observed. Calculation oft t the velocity of the passive admixture spreading in the Baltic Sea is presented

  2. Investigation of sea-level changes and shelf break prograding sequences during the Late Quaternary offshore of Kusadasi (West Anatolia) and surroundings by high resolution seismic methods

    Science.gov (United States)

    Gurcay, Savas; Cifci, Gunay; Dondurur, Derman; Okay, Seda; Atgin, Orhan; Ozel, Ozkan; Mert Kucuk, Hilmi

    2016-04-01

    High Resolution multi-channel seismic reflection and Chirp data were collected by K. Piri Reis, research vessel of Dokuz Eylül University, in the central Aegean coast of the West Anatolia by research cruises carried out in 2005 and 2008, respectively. Submarine stratigraphic and structural features of Sıǧacık Gulf, Kuşadası Gulf and surroundings were investigated under this survey. The data were processed and interpreted in SeisLab, D.E.U. Marine Sciences and Technology seismic laboratory. Thirteen distinct unconformities can be traced below the study area that separate thirteen progradational stacked paleo-delta sequences (Lob1-Lob13) on seismic profiles following and cutting each other. As a result of comparison with the oxygen isotopic stages (δ18), these deltas (Lob1-L13) were interpreted that they have been deposited during the sea-level lowstands within Pleistocene glacial stages. In the study area the basement surface which observed as the lowest unconformity surface of the seismic sections was called 'Acoustic Basement'. This basement which traced approximately all of the seismic sections has generally quite wavy surface and underlain the upper seismic units. It was observed that these seismic units which terminated their formation in Pleistocene (Lob1-Lob13) and Holocene period were cut and uplifted by acoustic basement, like an intrusion. These type deformations were interpreted as a result of magmatic intrusion into these upper seismic units occurred in Late Pleistocene and Holocene period. Tectonic and structural interpretation was carried out to constitute the submarine active tectonic map of the study area by correlated active faults identified on seismic sections. Submarine active tectonic map and, basement topography and sediment thickness map were correlated together to present the relationship between tectonic deformation and stratigraphy.

  3. Damages to the Black Sea, Caspian Sea and Baltic Sea by the invader comb jelly Mnemiopsis leidyi

    OpenAIRE

    Elif Eker Develi; Aydın Sellioğ; Nuray Öner

    2011-01-01

    In the present study changes in ecosystems of the Black Sea, Caspian Sea and Baltic Sea after the invasion of ctenophore Mnemiopsis leidyi were investigated. Excessive increase in plant plankton as a result of antrophogenic eutrophication leads to a shift in mesozooplankton com¬position, which is the main food item of these comb jellies. For instance, while some mesozoo¬plankton species disappeared from the environment or substantially decreased in number, some others increased in quantity. T...

  4. The Suspended Sediment Concentration Distribution in the Bohai Sea, Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    BIAN Changwei; JIANG Wensheng; Richard J.Greatbatch; DING Hui

    2013-01-01

    The distribution of the suspended sediment eoncentration (SSC) in the Bohai Sea,Yellow Sea and East China Sea (BYECS) is studied based on the observed turbidity data and model simulation results.The observed turbidity results show that (i)the highest SSC is found in the coastal areas while in the outer shelf sea areas turbid water is much more difficult to observe,(ii) the surface layer SSC is much lower than the bottom layer SSC and (iii) the winter SSC is higher than the summer SSC.The Regional Ocean Modeling System (ROMS) is used to simulate the SSC distribution in the BYECS.A comparison between the modeled SSC and the observed SSC in the BYECS shows that the modeled SSC can reproduce the principal features of the SSC distribution in the BYECS.The dynamic mechanisms of the sediment erosion and transport processes are studied based on the modeled results.The horizontal distribution of the SSC in the BYECS is mainly determined by the current-wave induced bottom stress and the fine-grain sediment distribution.The current-induced bottom stress is much higher than the wave-induced bottom stress,which means the tidal currents play a more significant role in the sediment resuspension than the wind waves.The vertical mixing strength is studied based on the mixed layer depth and the turbulent kinetic energy distribution in the BYECS.The strong winter time vertical mixing,which is mainly caused by the strong wind stress and surface cooling,leads to high surface layer SSC in winter.High surface layer SSC in summer is restricted in the coastal areas.

  5. Sea-level variation/change and thermal contribution in the Bering Sea

    Institute of Scientific and Technical Information of China (English)

    ZUO Juncheng; ZHANG Jianli; DU Ling; LI Peiliang; LI Lei

    2005-01-01

    The long-term sea-level trend in the Bering Sea is obtained by the analysis of TOPEX/Poseidon altimeter data, including the data of two tide gauges. The averaged sea-level in the Bering Sea rises at a rate of 2.47 mm/a from 1992 to 2002. The mean sea-level is falling in the most part of the Bering Sea, especially in its central basin, and it is rising in the northeastern part of the Bering Sea. During the 1998/99 change, the sea-level anomaly differences exhibit a significant sea-level anomaly fall in the deep basin of the Bering Sea,which is roughly in the same position where a prominent SST fall exists. The maximal fall of sea-level is about 10 cm in the southwestern part of the Bering Sea, and the maximal fall of about 2℃ in the SST also appeared in the same region as the sea level did.The steric sea-level change due to temperature variations is discussed. The results are compared with the TOPEX/Poseidon altimeter data at the different spatial scales. It is indicated that the seasonal amplitude of the steric height is about 35% of the observed TOPEX/Poseidon amplitude, which is much smaller than the 83% in the mid-latitudes area. The systematic difference between the TOPEX/Poseidon data with the range of about 7.5 cm and the thermal contribution with the range of about 2.5 cm is about 5 cm. This indicates that the thermal effect on the sea level is not as important as the case in the mid-latitudes area. In the Bering Sea, the phase of the steric height leads the observed sea level by about three months.

  6. Riverine input of chlorinated hydrocarbons in the coastal pollution

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Everaarts, J.M.

    This chapter presents an overview of the contamination of the coastal ecosystem of the North Sea, Arabian Sea, Bay of Bengal, East China Sea, Atlantic Sea, Aegean Sea, East Java Sea, Australian coast and the Mediterranean Sea due to riverine input...

  7. Cleaning up the sea bed in the North Sea. 1994

    International Nuclear Information System (INIS)

    The yearly raid was executed in an efficient way and without excess technical equipment interruptions. The vessel ''Lance'' owned by the Norwegian Sea Mapping Authorities which was used for the sonar mapping of the sea bed, was equipped with a Klein 531T side seeking sonar, a Simrad echo sounder of the type EM100 (multiray) and differential GPS navigation system. The executive committee has earlier expressed desire for a strengthening of the co-operation with the Norwegian Sea Mapping Authorities. The use of the vessel was in accordance with this wish. Stolt Comex Seaway A/S used the vessel M/S ''Seaway Commander'' and the underwater vessel ''Solo'' for the cleaning up project. The systems worked satisfactory during the entire operation. The cleaning operation was in 1994 carried out in 2 sections. The Petroleum Directorate agreed to letting the M/S ''Seaway Commander'' complete the project for Norsk Hydro at the Troll field in order to avoid delays in the Troll Oil project. In both periods there were good weather conditions. There was no extensive discontinuations due to the weather. During the two periods of 13,5 days 259 out of 370 positions were investigated visually through the systems. This is in average about 20 inspected positions a day. The reason for the high average is that the sailing distances are short between the positions and the findings corresponded to stated positions and sonar interpretations. Also this year there was installed a side seeking sonar in the underwater vessel which resulted in reduced investigation time at each aim. It was possible with this type of sonar to identify the goal quicker and to seek during transit between goals at moderate distances. Few articles with certainty contributed by the petroleum activities were retrieved

  8. The carbon budget of the North Sea

    Directory of Open Access Journals (Sweden)

    A. Vieira Borges

    2004-08-01

    Full Text Available A carbon budget has been established for the North Sea, a shelf sea of the NW European continental shelf. The air-sea exchange of CO2 has been assessed as closing term of the budget. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the marine carbon cycle – is dominated by the carbon inputs from rivers, the Baltic Sea and the atmosphere. The dominant carbon sink is the final export to the North Atlantic Ocean. The North Sea acts as a sink for organic carbon. More than 90% of the CO2 taken up from the atmosphere is exported to the North Atlantic Ocean making the North Sea a highly efficient continental shelf pump for carbon.

  9. Physics of the nucleon sea quark distributions

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2000-03-10

    Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However,recent experiments have called these naive expectations into question. A violation of the Gottfried sum rule has been measured in several experiments, suggesting that (bar u) < (bar d) in the proton. Additionally, other measurements, while not definitive, show that there may be an asymmetry in the strange and anti-strange quark sea distributions. These effects may require nonperturbative explanations. In this review we first discuss the perturbative aspects of the sea quark distributions. We then describe the experiments that could point to nonperturbative contributions to the nucleon sea. Current phenomenological models that could explain some of these effects are reviewed.

  10. GHRSST Level 4 EUR Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 2)

    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 by Ifremer/CERSAT (France) using optimal...

  11. 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

    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...... exported from the Arctic Ocean into the East Greenland current and the Nordic Seas plays an important and overlooked role in regulating the surface water partial pressure of CO2 and increases the seasonal CO2 uptake in the area by approximately 50%....... 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...

  12. First biological measurements of deep-sea corals from the Red Sea.

    KAUST Repository

    Roder, C

    2013-10-03

    It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with \\'deep-sea\\' and \\'cold-water\\' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

  13. Oceanographic cruise: Coral Sea, Arafura Sea, and Java Trench, April - May 1969 (NODC Accession 7100914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard HMAS DIAMANTINA during an oceanographic cruise in the Coral Sea, Arafura Sea, and Java Trench...

  14. Impact of sea ice initialization on sea ice and atmosphere prediction skill on seasonal timescales

    Science.gov (United States)

    Guemas, V.; Chevallier, M.; Déqué, M.; Bellprat, O.; Doblas-Reyes, F.

    2016-04-01

    We present a robust assessment of the impact of sea ice initialization from reconstructions of the real state on the sea ice and atmosphere prediction skill. We ran two ensemble seasonal prediction experiments from 1979 to 2012 : one using realistic sea ice initial conditions and another where sea ice is initialized from a climatology, with two forecast systems. During the melting season in the Arctic Ocean, sea ice forecasts become skilful with sea ice initialization until 3-5 months ahead, thanks to the memory held by sea ice thickness. During the freezing season in both the Arctic and Antarctic Oceans, sea ice forecasts are skilful for 7 and 2 months, respectively, with negligible differences between the two experiments, the memory being held by the ocean heat content. A weak impact on the atmosphere prediction skill is obtained.

  15. GHRSST Level 4 ODYSSEA Mediterranean 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 at Ifremer/CERSAT...

  16. Ice sheets and sea-level changes

    OpenAIRE

    Alley, R.; Clark, P.U.; Huybrechts, Philippe; Joughin, I.

    2005-01-01

    Future sea-level rise is an important issue related to the continuing buildup of atmospheric greenhouse-gas concentrations. The Greenland and Antarctic ice sheets, with the potential to raise sea level ~70 m if completely melted, dominate uncertainties in projected sea-level change. Freshwater fluxes from these ice sheets also may affect oceanic circulation, contributing to climate change. Observational and modeling advances have reduced many uncertainties related to ice sheet behavior, but r...

  17. A Sea Level Equation for seismic perturbations

    OpenAIRE

    Melini, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Spada, G.; Istituto di Fisica, Università di Urbino; Piersanti, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia

    2009-01-01

    Large earthquakes are a potentially important source of relative sea level variations, since they can drive global deformation and simultaneously perturb the gravity field of the Earth. For the first time, we formalize a gravitationally self–consistent, integral sea level equation suitable for earthquakes, in which we account both for direct effects by the seismic dislocation and for the feedback from water loading associated with sea level changes. Our approach builds upon ...

  18. Global sea level linked to global temperature

    OpenAIRE

    Vermeer, M.; Rahmstorf, S.

    2009-01-01

    We propose a simple relationship linking global sea-level variations on time scales of decades to centuries to global mean temperature. This relationship is tested on synthetic data from a global climate model for the past millennium and the next century. When applied to observed data of sea level and temperature for 1880–2000, and taking into account known anthropogenic hydrologic contributions to sea level, the correlation is >0.99, explaining 98% of the variance. For future global temperat...

  19. On Sea Level - Ice Sheet Interactions

    OpenAIRE

    Gomez, Natalya Alissa

    2013-01-01

    This thesis focuses on the physics of static sea-level changes following variations in the distribution of grounded ice and the influence of these changes on the stability and dynamics of marine ice sheets. Gravitational, deformational and rotational effects associated with changes in grounded ice mass lead to markedly non-uniform spatial patterns of sea-level change. I outline a revised theory for computing post-glacial sea-level predictions and discuss the dominant physical effects that c...

  20. Holocene sea level change in Malta

    OpenAIRE

    Furlani, S; Antonioli, F.; ENEA, Casaccia, Rome, Italy; S. Biolchi; T. Gambin; R. Gauci; Lo Presti, V.; Anzidei, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; M Palombo; Saulli, A.

    2012-01-01

    A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman ...

  1. Scientific reticence and sea level rise

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, J E [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States)

    2007-04-01

    I suggest that a 'scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.

  2. Scientific reticence and sea level rise

    OpenAIRE

    Hansen, J.E.

    2007-01-01

    I suggest that a "scientific reticence" is inhibiting communication of a threat of potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.

  3. Status of Biodiversity in the Baltic Sea

    OpenAIRE

    Ojaveer, Henn; Jaanus, Andres; MacKenzie, Brian; Martin, Georg; Olenin, Sergej; Radziejewska, Teresa; Telesh, Irena; Zettler, Michael L.; Zaiko, Anastasija

    2010-01-01

    The brackish Baltic Sea hosts species of various origins and environmental tolerances. These immigrated to the sea 10,000 to 15,000 years ago or have been introduced to the area over the relatively recent history of the system. The Baltic Sea has only one known endemic species. While information on some abiotic parameters extends back as long as five centuries and first quantitative snapshot data on biota (on exploited fish populations) originate generally from the same time, international co...

  4. Virtual SEA Analysis of a Warship Classification

    OpenAIRE

    Borello, Gérard

    2010-01-01

    In the mid-frequency (MF) range, the number of modes of warships is very large. Predicting power radiated by the underwater part of the shell becomes difficult with a classical modal synthesis. Statistical methods such as SEA (Statistical Energy Analysis) are also limited in their capability of modelling the structural complexity. Virtual SEA method is introduced to get benefit of both deterministic modal synthesis and SEA approaches to build a fully predictive model in the MF range. Virtual ...

  5. Sea Surface Salinity : Research Challenges and Opportunities

    Science.gov (United States)

    Halpern, David; Lagerloef, Gary; Font, Jordi

    2012-01-01

    Sea surface salinity (SSS) can be important in regulating sea surface temperature (SST). Two technological breakthrough satellite SSS missions, Aquarius and Soil Moisture and Ocean Salinity (SMOS), are currently producing high-quality SSS data. This paper provides an overview of the importance of SSS for weather and climate applications and describes the Aquarius and SMOS missions. The newness of adequately sampled SSS data prompted a first-time at-sea field campaign devoted to improved understanding of SSS variations.

  6. Sea otter health: Challenging a pet hypothesis.

    Science.gov (United States)

    Lafferty, Kevin D

    2015-12-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission. PMID:26155464

  7. Sea otter health: Challenging a pet hypothesis

    Directory of Open Access Journals (Sweden)

    Kevin D. Lafferty

    2015-12-01

    Full Text Available A recent series of studies on tagged sea otters (Enhydra lutris nereis challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission.

  8. Sea otter health: Challenging a pet hypothesis

    OpenAIRE

    Lafferty, Kevin D.

    2015-01-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of...

  9. Parasites in the Wadden Sea food web

    Science.gov (United States)

    Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

    2013-09-01

    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 a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

  10. Arctic tides from GPS on sea ice

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Skourup, Henriette; Forsberg, René

    The presence of sea-ice in the Arctic Ocean plays a significant role in the Arctic climate. Sea ice dampens the ocean tide amplitude with the result that global tidal models which use only astronomical data perform less accurately in the polar regions. This study presents a kinematic processing of...... Global Positioning System (GPS) buoys placed on sea-ice at five different sites north of Greenland for the study of sea level height and tidal analysis to improve tidal models in the Central Arctic. The GPS measurements are compared with the Arctic tidal model AOTIM-5, which assimilates tide-gauges and...

  11. Context awareness and sensitivity in SEA implementation

    International Nuclear Information System (INIS)

    The Impact Assessment research community repeatedly asserts that the implementation of Strategic Environmental Assessment (SEA) should take the issue of context into consideration. The primary aim of this paper then is to attempt to give substance to the concept of 'context' in relation to the implementation of SEA. The second aim is to discuss the relevance of context consciousness and sensitivity in relation to one of the main aims given to SEA implementation i.e. to contribute to the 'integration' of environmental perspectives in planning processes. Context must be defined in relation to a certain question. In this paper the question in focus is the assumption that SEA implementation will contribute to integration of environmental issues in planning processes. Research results relating to the use of environmental tools, like for example SEA, and experiences of integration efforts, strongly indicate that the use of a single tool like SEA is not enough to achieve this integration. The current 'context free' normative and procedural assumptions concerning the aim of SEA implementation and 'best practice' in term of SEA can be criticised on the same grounds as normative and procedural planning theories, as being context free. The assumptions behind the current formulations of the aim and best practice of SEA need to be revisited. A firm empirical and theoretical knowledge and discussion is needed, especially in relation to the issue of context and integration. This paper provides a starting point in this direction

  12. Comparison among four kinds of data of sea surface wind stress in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    谢强; 王卫强; 毛庆文

    2002-01-01

    By using remote sensing (ERS) data, FSU data, GOADS data and Hellerman & Rcsenstein objective analysis data to analyze the sea surface wind stress in the South China Sea, it is found that the remote sensing data have higher resolution and more reasonable values. Therefore we suggest that remote sensing data be chosen in the study of climatological features of sea surface wind stress and its seasonal variability in the South China Sea, especially in the study of small and middle scale eddies.

  13. Sea level data archaeology and the Global Sea Level Observing System (GLOSS)

    OpenAIRE

    Elizabeth Bradshaw; Lesley Rickards; Thorkild Aarup

    2015-01-01

    The Global Sea Level Observing System (GLOSS) Group of Experts (GE) data archaeology group is collating tools and producing guidelines for historic sea level data. They aim to aid the discovery, scanning, digitising and quality control of analogue tide gauge charts and sea level ledgers. Their goal is to improve the quality, quantity and availability of long-term sea level data series. This paper examines different tools for the automatic digitisation of tide gauge charts, the methods availab...

  14. Tahiti sea level expedition : the last deglacial sea level rise in the South Pacific

    OpenAIRE

    Camoin, Gilbert F; Iryu, Yasufumi; McInroy, David

    2005-01-01

    The history of sea level and sea-surface temperature (SST) variation associated with the last deglaciation is of prime interest to understanding dynamics of large ice sheets and their effects on Earth’s isostasy. So far, the only sea level record that encompasses the whole deglaciation is based on offshore drilling of Barbados coral reefs that overlie an active subduction zone, implying that the apparent sea level record may be biased by tectonic movements. This proposal seeks to establish th...

  15. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    OpenAIRE

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems o fthe Mediterranean Sea (200 to mo...

  16. Sea level ~400 000 years ago (MIS 11): analogue for present and future sea-level?

    OpenAIRE

    D. Q. Bowen

    2010-01-01

    Comparison of the sea-level today with that of 400 000 years ago (MIS 11), when the Earth's orbital characteristics were similar may provide, under conditions of natural variability, indications of future sea-level during the present interglacial. Then, as now, orbital eccentricity was low and precession dampened. Evidence for MIS 11 sea-level occurs on uplifting coastlines where shorelines with geochronological ages have been preserved. The sea-level term and the uplift term may be separated...

  17. Transport of radionuclides in the Kara Sea and Eastern Barents Sea

    International Nuclear Information System (INIS)

    The Arctic seas are influenced by radioactive contamination from military and civilian sources such as global fallout, discharges from reprocessing plants, river transport and the Chernobyl fallout. Potential sources are dumped radioactive waste in the Kara Sea. A joint Norwegian American field expedition to the Kara Sea was carried out in August-September 1995. An expedition to the Eastern Barents Sea was conducted in September 1996

  18. Air-sea CO2 fluxes on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    M. A. Jeffries

    2010-10-01

    Full Text Available There have been few previous studies of surface seawater CO2 partial pressure (pCO2 variability and air-sea CO2 gas exchange rates for the Bering Sea shelf which is the largest US coastal shelf sea. In 2008, spring and summertime observations were collected in the Bering Sea shelf as part of the Bering Sea Ecological Study (BEST. Our results indicate that the Bering Sea shelf was close to neutral in terms of CO2 sink-source status in springtime due to relatively small air-sea CO2 gradients (i.e., Δ pCO2 and sea-ice cover. However, by summertime, very low seawater pCO2 values were observed and much of the Bering Sea shelf became strongly undersaturated with respect to atmosphere CO2 concentrations. Thus the Bering Sea shelf transitions seasonally from mostly neutral conditions to a strong oceanic sink for atmospheric CO2 particularly in the "green belt" region of the Bering Sea. Ocean biological processes dominate the seasonal drawdown of seawater pCO2 for large areas of the Bering Sea shelf, with the effect partly countered by seasonal warming. In small areas of the Bering Sea shelf south of the Pribilof Islands and in the SE Bering Sea, seasonal warming is the dominant influence on seawater pCO2, shifting localized areas of the shelf from minor/neutral CO2 sink status to neutral/minor CO2 source status, in contrast to much of the Bering Sea shelf. We compute that the Bering Sea shelf CO2 sink in 2008 was 157 Tg C yr−1 (Tg = 1012 g C and a stronger sink for CO2 than previously demonstrated by other studies.

  19. The sea ice thickness distribution in the northwestern Weddell Sea

    Science.gov (United States)

    Lange, M. A.; Eicken, H.

    1991-03-01

    We present new data on distribution of snow and sea ice thicknesses in the northwestern Weddell Sea. The data were obtained through direct measurements along 19 profiles, each approximately 100 m long on 17 different floes located between 54°-46°W and 59°-64°S. The overall probability density functions (PDFs) for ice thicknesses reflect the complex mixture of first-, second-, and multi-year ice to be expected in the outflowing branch of the Weddell Gyre. Further differentiation of the data reveals four distinct thickness classes which reflect differences in the formation and subsequent histories of the ice encountered. These classes (I-IV) represent strongly deformed first year ice, less deformed first- and second-year ice, and deformed second- or multi-year ice, respectively. Each of the classes is characterized by a specific set of quantities related to ice texture and surface snow characteristics and by distinct PDFs for snow and ice thicknesses. In addition, geometric surface and bottom roughness characteristics differ significantly for each of the floe classes.

  20. Environmental security of coastal seas

    International Nuclear Information System (INIS)

    Full text: The bottoms of the coastal seas are contaminated by many man-made objects including a variety of ammunition. This contamination is world wide spread with some areas being highly polluted presenting a serious threat to local population and to visitors as well. All littoral nations are investing lots of effort into the remediation of their coastal areas. In this report an effort to identify the nature of the object on the sea bottom is presented. Once the presence of the anomaly on the bottom of the shallow coastal sea water is confirmed (by visual identification and by using one or several sensors, namely magnetometer, sonar and optical cameras) it is necessary to establish if it contains explosive and/or chemical warfare charge. In our work we propose this to be performed by using neutron sensor installed within an underwater vessel - 'Surveyor'. When positioned above the object, or to its side, the system inspects the object for the presence of the threat material by using alpha particle tagged neutrons from the sealed tube d+t neutron generator. The inside of the first prototype of the underwater system 'Surveyor' containing neutron generator, shielding and gamma ray detector is shown in figure. The neutron generator used by the 'Surveyor' is rotated by two step motors so that different volume elements chosen by the relative position of the neutron generator and gamma ray detector could be inspected. In such a way a profile of concentrations could also be measured. The preliminary results from the laboratory tests are presented

  1. UN adopts Law of Sea

    Science.gov (United States)

    Richman, Barbara T.

    After more than 8 years of diplomatic wrangling, the United Nations Convention on the Law of the Sea was adopted on April 30 by a vote of 130 to 4. The United States, Israel, Turkey, and Venezuela voted against the treaty; 17 nations—including the Soviet Union, West Germany, and Britain—abstained.The treaty, which would give nations the exclusive rights to natural resources in the continental shelf up to approximately 650 km offshore, will be signed in December. The treaty becomes effective 1 year after at least 60 nations ratify it.

  2. Sea level trends for all sections of the Baltic Sea coastline

    Science.gov (United States)

    Madsen, Kristine S.; Høyer, Jacob L.; Suursaar, Ülo; Knudsen, Per; She, Jun

    2016-04-01

    To better understand influence of sea level rise on societal vulnerability and coastal erosion processes, it is important to know the sea level trend. The coastline of the Baltic Sea is not uniformly exposed, and therefore we will determine the sea level trend of the last 10, 50 and 100 years for all sections of the coastline. The observational record of sea level in the Baltic Sea is quite unique with several records of more than 100 years of data. However, the information is confined to the tide gauge locations. Here, we utilize a statistical method based on least squares regression and originally developed for short term sea level variability (Madsen et al. 2015, JGR, doi:10.1002/2015JC011070) to spread out the sea level information from selected tide gauges to all sections of the Baltic Sea coast. Monthly mean tide gauge observations are retrieved from PSMSL and supplemented with Estonian observations. The spatial distribution of the sea level is obtained from model reanalysis from the Copernicus Marine Service and satellite altimetry observations and land rise information is taken into account. Results are validated against independent tide gauges, providing a consistent record of 20th century sea level trends and variability, including uncertainties, for the entire Baltic Sea coastline. This work is sponsored by the EMODnet project Baltic Checkpoint.

  3. Sea state estimation from an advancing ship – A comparative study using sea trial data

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Stredulinsky, David C.

    2012-01-01

    Onboard sea state estimation is relevant for evaluation of ship operations at sea. Means to obtain the sea state at a fixed position include a traditional wave rider buoy, where motion measurements of the buoy are processed to give the (directional) wave spectrum. The analogy between a ship...

  4. Sea Turtle Conservation on Bonaire. Sea Turtle Club Bonaire 1997. Project Report

    NARCIS (Netherlands)

    Schuit, M.; Put, van A.L.L.M.; Valkering, N.P.; Eijck, van T.J.W.

    1998-01-01

    The Sea Turtle Club Bonaire (STCB) is a non-governmental, non-profit organization. Its main goal is the conservation of the sea turtles that occur on Bonaire. To reach this goal, annual projects are undertaken, such as research and the promotion of public awareness on sea turtle conservation. The ST

  5. On the sea-ice cover of the Nordic Seas in an idealized MITgcm-setup

    Science.gov (United States)

    Jensen, Mari F.; Spall, Michael A.; Nisancioglu, Kerim H.

    2016-04-01

    Changes in the sea-ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard-Oeschger events during the last glacial. However, with its proximity to the warm Atlantic water, how a sea-ice cover can persist in the Nordic Seas is not well understood. In this study, we apply an eddy-resolving configuration of the Massachusetts Institute of Technology general circulation model with an idealized topography to study the presence of sea ice in a Nordic Seas-like domain. The sea-surface temperatures are restored toward cold, atmospheric temperatures, and as a result, sea ice is present in the interior of the domain. However, the warm, cyclonic boundary current prevents sea ice from being formed along the boundaries. Preliminary results suggest that freshwater inputs at the margins can introduce sea ice in the warm, cyclonic boundary. In addition, a reduction in the meridional heat transport and a shift in the vertical location of the warm inflowing water is observed when freshwater is introduced. The magnitude and location of the freshwater input will be studied, along with changes in the temperature of the inflowing warm water. Results suggest a threshold value in the freshwater forcing for when sea ice is present in the boundaries, and a sea-ice cover which is sensitive to the temperature of the inflowing, warm water.

  6. Long Term Sea Level Change and Water Mass Balance in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    RONG Zengrui; LIU Yuguang; ZONG Haibo; XIU Peng

    2009-01-01

    Sea level anomalies observed by altimeter during the 1993-2006 period, thermosterie sea level anomalies estimated by using subsurface temperature data produced by Ishii and SODA reanalysis data, tide gauge records and HOAPS freshwater flux data were analyzed to investigate the long term sea level change and the water mass balance in the South China Sea. The altimeter-observed sea level showed a rising rate of (3.5±0.9)mm yr-1 during the period 1993-2006, but this figure was considered to have been highly distorted by the relatively short time interval and the large inter-decadal variability, which apparently exists in both the thermosteric sea level and the observed sea level. Long term thermosteric sea level from 1945 to 2004 gave a rising rate of 0.15±0.06 mmyr-1. Tide gauge data revealed this discrepancy and the regional distributions of the sea-level trends. Both the 'real' and the thermosteric sea level showed a good correspondence to ENSO: decreasing during E1 Nifio years and increasing during La Nina years. Amplitude and phase differences between the 'real' sea level and the thermosteic sea level were substantially revealed on both seasonal and interannual time scales. As one of the possible factors, the freshwater flux might play an important role in balancing the water mass.

  7. Long-term sea level change in the Malaysian seas from multi-mission altimetry data

    NARCIS (Netherlands)

    Din, A.H.; Omar, K.M.; Naeije, M.C.; Ses, S.

    2012-01-01

    The long-term sea level change during 1993 to 2008 was investigated in the Malaysian seas from satellite altimetry data of the TOPEX, JASON-1, ERS-1, ERS-2 and ENVISAT missions. Sea level data retrieval and reduction were carried out using the radar altimeter database system (RADS). In RADS data pro

  8. Filling regulatory gaps in high seas fisheries: discrete high seas fish stocks, deep-sea fisheries and vulnerable marine ecosystems

    NARCIS (Netherlands)

    Takei, Y.

    2008-01-01

    The present study examines the legal regime of high seas fisheries with a view to identifying regulatory gaps. The main research questions are as follows: 1. What general principles are applicable to high seas fisheries?; 2. What implications do these general principles have for new challenges in th

  9. Deep-sea pollen research in China

    Institute of Scientific and Technical Information of China (English)

    SUN Xiangjun; LUO Yunli; CHEN Huaicheng

    2003-01-01

    This paper briefly presents the progress of deep-sea pollen research in China since the beginning ofninetieths of the last Century. All the deep-sea pollen contri-butions mainly come from the South China Sea (SCS) andthe East China Sea (ECS). The German-Chinese joint cruise(Sonne 95) and ODP 184 cruise initiated by Chinese scientistsin the SCS provided excellent material for the deep-sea pol-len research. So far a number of pollen results of 20-30 kaand million years from the SCS have been published. A couple of deep-sea pollen records from Okinawa Through of the ECS also came out. The high resolution pollen records obtained from the continuous deposits with high sedimentation rates and reliable age control of the deep-sea sediments provided a high time resolution history (hundred to millennial scales) of vegetation, environment and monsoon evolution of the pollen source areas (southern China and Japan). Spectral analysis of deep-sea pollen records from the SCS discovered orbital (100, 41, 23, 10 ka) and suborbital cyclicities (Heinrich and Dansgaard/Oscheger-O/D events) in the vege-tation changes. Moreover, cross spectral analysis showed that the trend of vegetation changes in northern SCS was regulated mainly by changes of the ice volume in the Northern Hemisphere. The pollen record of the last 20 ka from the Okinawa Through of the ECS indicates that the marine environmental change lagged that on the terrestrail by about 1000 year. The asynchronous environmental changes between land and sea were probably caused by the time difference in thermohaline circulation. This study underscored the role of the deep-sea plant fossils as a bridge across the land and sea.

  10. Air-sea CO2 fluxes on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    M. A. Jeffries

    2011-05-01

    Full Text Available There have been few previous studies of surface seawater CO2 partial pressure (pCO2 variability and air-sea CO2 gas exchange rates for the Bering Sea shelf. In 2008, spring and summertime observations were collected in the Bering Sea shelf as part of the Bering Sea Ecological Study (BEST. Our results indicate that the Bering Sea shelf was close to neutral in terms of CO2 sink-source status in springtime due to relatively small air-sea CO2 gradients (i.e., ΔpCO2 and sea-ice cover. However, by summertime, very low seawater pCO2 values were observed and much of the Bering Sea shelf became strongly undersaturated with respect to atmospheric CO2 concentrations. Thus the Bering Sea shelf transitions seasonally from mostly neutral conditions to a strong oceanic sink for atmospheric CO2 particularly in the "green belt" region of the Bering Sea where there are high rates of phytoplankton primary production (PPand net community production (NCP. Ocean biological processes dominate the seasonal drawdown of seawater pCO2 for large areas of the Bering Sea shelf, with the effect partly countered by seasonal warming. In small areas of the Bering Sea shelf south of the Pribilof Islands and in the SE Bering Sea, seasonal warming is the dominant influence on seawater pCO2, shifting localized areas of the shelf from minor/neutral CO2 sink status to neutral/minor CO2 source status, in contrast to much of the Bering Sea shelf. Overall, we compute that the Bering Sea shelf CO2 sink in 2008 was 157 ± 35 Tg C yr−1 (Tg = 1012 g C and thus a strong sink for CO2.

  11. A Heavy Sea Fog Event over the Yellow Sea in March 2005:Analysis and Numerical Modeling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, a heavy sea fog episode that occurred over the Yellow Sea on 9 March 2005 is investigated.The sea fog patch, with a spatial scale of several hundred kilometers at its mature stage, reduced visibility along the Shandong Peninsula coast to 100 m or much less at some sites. Satellite images, surface observations and soundings at islands and coasts, and analyses from the Japan Meteorology Agency (JMA) are used to describe and analyze this event. The analysis indicates that this sea fog can be categorized as advection cooling fog. The main features of this sea fog including fog area and its movement are reasonably reproduced by the Fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5). Model results suggest that the formation and evolution of this event can be outlined as:(1) southerly warm/moist advection of low-level air resulted in a strong sea-surface-based inversion with a thickness of about 600 m; (2) when the inversion moved from the warmer East Sea to the colder Yellow Sea, a thermal internal boundary layer (TIBL) gradually formed at the base of the inversion while the sea fog grew in response to cooling and moistening by turbulence mixing; (3) the sea fog developed as the TIBL moved northward and (4) strong northerly cold and dry wind destroyed the TIBL and dissipated the sea fog. The principal findings of this study are that sea fog forms in response to relatively persistent southerly warm/moist wind and a cold sea surface, and that turbulence mixing by wind shear is the primary mechanism for the cooling and moistening the marine layer. In addition, the study of sensitivity experiments indicates that deterministic numerical modeling offers a promising approach to the prediction of sea fog over the Yellow Sea but it may be more efficient to consider ensemble numerical modeling because of the extreme sensitivity to model input.

  12. Future acidification of marginal seas: A comparative study of the Japan/East Sea and the South China Sea

    Science.gov (United States)

    Luo, Yiming; Boudreau, Bernard P.

    2016-06-01

    The response of marginal (peripheral) seas to ocean acidification on short and long time scales is not well established. Through modeling, we examine the future acidification of two adjacent marginal seas, the South China Sea (SCS) and the Japan/East Sea (J/ES). Our results illustrate the importance of unique features in determining their acidification. The J/ES basin will become completely undersaturated with regard to calcite rapidly in the next few decades, while the SCS basin will experience relatively slower acidification. During its acidification, the J/ES will continually act as a sink for atmospheric CO2, whereas the SCS will temporarily switch from a source to a sink during the peak pCO2 interval, only to return slowly to being a source again. Marginal sea acidification will be determined by multiple factors, including their connections with the open ocean and their unique physical and biogeochemical dynamics, in addition to the level of atmospheric CO2.

  13. Deep-sea pleistocene biostratigraphy.

    Science.gov (United States)

    Lidz, L

    1966-12-16

    The first detailed paleontological analysis of a deep-sea pistoncore from the Caribbean Sea has been completed. The core, P6304-8, was raised from 3927 meters, east of Beata Ridge at 14 degrees 59'N, 69 degrees 20'W. Formerly, stratigraphic works in this area were based on studies of paleotemperature, measured by the oxygen isotope mass spectrometry method, or on micropaleontological analysis by means of rapid or cursory examinations. For core P6304-8, samples for foraminiferal analysis were taken at 10-centimeter intervals and split into smaller samples containing an average of 710 individuals (smallest sample, 517 individuals); all individuals were then identified and counted. By use of data derived from populations of this size, a statistical reliability was insured within a 5 percent limnit. Temperature oscillations, the best method of portraying Pleistocene stratigraphy, were shown by using ratios of the relative abundances of tropical and subtropical planktonic foraminifera to those found in temperate and cooler waters. These ratios correlate well with existing paleotemperature measurements for the same core, obtained by the oxygen isotope mass spectrometry method. PMID:17821563

  14. BACTERIAL DESEASES IN SEA FISH

    Directory of Open Access Journals (Sweden)

    Ivančica Strunjak-Perović

    1997-10-01

    Full Text Available With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites. Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis. Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture.

  15. Observations on sea water quality

    International Nuclear Information System (INIS)

    The water quality was observed periodically by measuring dissolved oxygen (DO), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in the inshore environment of Fukushima Nuclear Power Station during three years since 1971. Besides, some procedures for the measurement of COD and BOD were briefly examined. 1. Remarkable tendency was not observed between DO content and water temperature, but the seasonable change of DO content was shown at zero meter layer. 2. At the outlet, the DO content was less than the other study sites where oversaturated oxygen content was observed. Besides, oversaturated oxygen content was obtained at the outlet when unsaturated oxygen content was shown in surroundings. 3. The DO content had no definite relation among such study sites, which were situated radially about 25 km distant from the outlet. 4. Remarkable tendency was not observed between the quantities of water soluble organic substances and water temperature or DO content at zero meter layer. 5. The reproducibility of COD measurement was increased by retaining temperature exactly in heating procedure. 6. The method of BOD measurement was established by the pure culture of F-11-9 strain, which was isolated as the dominant species of bacteria in the sea area. 7. The quantity of organic substances soluble in sea water was reduced by the filtration of the sample before measurement. (J.P.N.)

  16. Legacy of the Sea Express

    International Nuclear Information System (INIS)

    In February 1996, an oil tanker, the Sea Empress, ran aground in high seas in Milford Haven in the United Kingdom. Over the course of a few days, 72,000 tonnes of crude oil and 360 tonnes of heavy fuel oil leaked from the ship into a maritime and coastal area of designated scientific importance and environmental sensitivity. The Countryside Council for Wales (CCW), who are responsible for nature conservation in the area, carried out immediate surveys of the coverage of oil on the coastline. The data was fed into the CCW's geographic information system (GIS) which also holds other spill-related and environmental information. The GIS provided an ideal storage and retrieval system to enable CCW rapidly to produce high quality maps of the affected area and accurately pinpoint the protected sites involved. In summer 1996, CCW carried out a second, more detailed survey. By this time the tides and mechanical recovery had dispersed all the major concentrations of oil. A thorough comparison of the two surveys will be carried out in order to assess and catalogue the removal of the oil by natural processes and the effectiveness of the shoreline treatment. (UK)

  17. Multisensor Analyzed Sea Ice Extent - Northern Hemisphere (MASIE-NH)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Multisensor Analyzed Sea Ice Extent Northern Hemisphere (MASIE-NH) products provide measurements of daily sea ice extent and sea ice edge boundary for the...

  18. Integral land subsidence study Wadden Sea

    International Nuclear Information System (INIS)

    The focus of the title study is on land subsidence and sea level rise as results of natural gas exploration and exploitation in the Netherlands, in particular in the Wadden Sea area. Also related environmental effects and impacts are taken into account for the period 1999-2050

  19. Moves toward self-management at sea

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    A discussion of efforts to promote self-management at sea covers the inability to impose upon sea staff involvement in management and financial responsibility and accountability; the need to generate and develop such interest; and organizational and training schemes being tried by such companies as Panocean-Anco Ltd., Esso Petroleum Co. Ltd., Jebsen (U.K.) Ltd., and Salenredrierna A.B.

  20. Teaching Wide Sargasso Sea in New Jersey

    Science.gov (United States)

    Jolley, Susan Arpajian

    2005-01-01

    High school teacher Susan Arpajian Jolley emphasizes experience and understanding by using the related novels "Wide Sargasso Sea" and "Jane Eyre" to help her students travel into unfamiliar cultural territory. "Wide Sargasso Sea" relates to Caribbean history and culture, feminism, race relations, colonialism, and personal identity.