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

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Ε. SOUVERMEZOGLOU

2014-12-01

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

Surveillance at sea : The transactional politics of border control in the Aegean

NARCIS (Netherlands)

Dijstelbloem, H.; van Reekum, R.; Schinkel, W.

2017-01-01

The relationship between vision and action is a key element of both practices and conceptualizations of border surveillance in Europe. This article engages with what we call the ‘operative vision’ of surveillance at sea, specifically as performed by the border control apparatus in the Aegean. We

Offshore wind power in the Aegean Sea

DEFF Research Database (Denmark)

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

hub heights at around 100 m using a combination of satellite wind fields and the long-term climate of atmospheric stability from the mesoscale model (Badger et al. 2016). The result of the mean wind speed at hub-height for the Aegean Sea is shown in Figure 1. The map shows the stability dependent......, where the spatial variations in wind speed are very high, accurate resource mapping is of great importance as the produced wind power is proportional to the cubed wind speed. It is challenging to model the wind resource and it is costly to measure from the ground at every place of interest. Maps based...

The large 1956 earthquake in the South Aegean: Macroseismic field configuration, faulting, and neotectonics of Amorgos Island

Science.gov (United States)

Papadopoulos, Gerassimos A.; Pavlides, Spyros B.

1992-10-01

New field observations of the seismic intensity distribution of the large (M s = 7.4) South Aegean (Amorgos) earthquake of 9 July 1956 are presented. Interpretations based on local ground conditions, structural properties of buildings and peculiarities of the rupture process lead to a re-evaluation of the macroseismic field configuration. This, together with the aftershock epicentral distribution, quite well defines the earthquake rupture zone, which trends NE-SW and coincides with the Amorgos Astypalea trough. The lateral extent of the rupture zone, however, is about 40% smaller than that predicted for Aegean earthquakes of M s = 7.4. This discrepancy could be attributed to sea-bottom topography changes, which seem to control the rupture terminations, and to relatively high stressdrop with respect to other Aegean earthquakes. Fault plane solutions obtained by several authors indicate either mainly normal faulting with a significant right-lateral strike-slip component or predominantly strike-slip motion. The neotectonism of Amorgos Island, based on new field observations, aerial photograph analysis and fault mechanisms, is consistent with the dip-slip interpretation. The neotectonic master fault of Amorgos and the 1956 seismic faulting appear to belong to the same tectonic phase (NE-SW strike and a southeasterly dip). However, the significant right-lateral strike-slip component supports the idea that the Amorgos region deviates from the simple description for pure extension in back-arc conditions.

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

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K. ANTONAKAKIS

2011-06-01

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

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

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M.A. PANCUCCI-PAPADOPOULOU

2010-05-01

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

Critically endangered fish species of Turkish Seas (Mediterranean and Aegean): Longfin gurnard, Chelidonichthys obscurus (Walbaum, 1792)

OpenAIRE

Cemal Turan; Deniz Ergüden; Mevlüt Gürlek

2016-01-01

Longfin gurnard Chelidonichthys obscurus (Walbaum, 1792) is reported several times from various researchers in the checklist of Turkish marine fishes. However, last three decades, the species is not occurred in the distributional range, comprising the northeastern Mediterranean Sea and Aegean Sea coast of Turkey. It is possibly critically endangered or absent in the Turkish Seas. Moreover, there has no any biological study been carried out on C. obscurus in Turkey. C. obscurus is considered t...

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

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I. A. Valioulis

1994-07-01

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.

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.

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

Science.gov (United States)

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

2016-09-01

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

Climatological Factors Affecting Electromagnetic Surface Ducting in the Aegean Sea Region

Science.gov (United States)

2012-03-01

low precipitation, and northeasterly winds, all due to changes in large scale circulations and a northward shift in extratropical storm tracks. The...differences over the Aegean region, that are governed by large-scale climate factors. a. Winter During winter, the Aegean area is subject to extratropical ... extratropical cyclones from entering the Aegean region, while opposite shifts can 18 allow extratropical cyclones to more frequently enter the Aegean

Investigation of Turbulence Parametrization Schemes with Reference to the Atmospheric Boundary Layer Over the Aegean Sea During Etesian Winds

Science.gov (United States)

Dandou, A.; Tombrou, M.; Kalogiros, J.; Bossioli, E.; Biskos, G.; Mihalopoulos, N.; Coe, H.

2017-08-01

The spatial structure of the marine atmospheric boundary layer (MABL) over the Aegean Sea is investigated using the Weather Research and Forecasting (WRF) mesoscale model. Two `first-order' non-local and five `1.5-order' local planetary boundary-layer (PBL) parametrization schemes are used. The predictions from the WRF model are evaluated against airborne observations obtained by the UK Facility for Airborne Atmospheric Measurements BAe-14 research aircraft during the Aegean-GAME field campaign. Statistical analysis shows good agreement between measurements and simulations especially at low altitude. Despite the differences between the predicted and measured wind speeds, they reach an agreement index of 0.76. The simulated wind-speed fields close to the surface differ substantially among the schemes (maximum values range from 13 to 18 m s^{-1} at 150-m height), but the differences become marginal at higher levels. In contrast, all schemes show similar spatial variation patterns in potential temperature fields. A warmer (1-2 K) and drier (2-3 g kg^{-1}) layer than is observed, is predicted by almost all schemes under stable conditions (eastern Aegean Sea), whereas a cooler (up to 2 K) and moister (1-2 g kg^{-1}) layer is simulated under near-neutral to nearly unstable conditions (western Aegean Sea). Almost all schemes reproduce the vertical structure of the PBL and the shallow MABL (up to 300 m) well, including the low-level jet in the eastern Aegean Sea, with non-local schemes being closer to observations. The simulated PBL depths diverge (up to 500 m) due to the different criteria applied by the schemes for their calculation. Under stable conditions, the observed MABL depth corresponds to the height above the sea surface where the simulated eddy viscosity reaches a minimum; under neutral to slightly unstable conditions this is close to the top of the simulated entrainment layer. The observed sensible heat fluxes vary from -40 to 25 W m^{-2}, while the simulated

TSUNAMI HAZARD ASSESSMENT IN THE NORTHERN AEGEAN SEA

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Barbara Theilen-Willige

2008-01-01

Full Text Available Emergency planning for the assessment of tsunami hazard inundation and of secondary effects of erosion and landslides, requires mapping that can help identify coastal areas that are potentially vulnerable. The present study reviews tsunami susceptibility mapping for coastal areas of Turkey and Greece in the Aegean Sea. Potential tsunami vulnerable locations were identified from LANDSAT ETM imageries, Shuttle Radar Topography Mission (SRTM, 2000 data and QuickBird imageries and from a GIS integrated spatial database. LANDSAT ETM and Digital Elevation Model (DEM data derived by the SRTM-Mission were investigated to help detect traces of past flooding events. LANDSAT ETM imageries, merged with digitally processed and enhanced SRTM data, clearly indicate the areas that may be prone to flooding if catastrophic tsunami events or storm surges occur.

Surveillance at sea: The transactional politics of border control in the Aegean.

Science.gov (United States)

Dijstelbloem, Huub; van Reekum, Rogier; Schinkel, Willem

2017-06-01

The relationship between vision and action is a key element of both practices and conceptualizations of border surveillance in Europe. This article engages with what we call the 'operative vision' of surveillance at sea, specifically as performed by the border control apparatus in the Aegean. We analyse the political consequences of this operative vision by elaborating on three examples of fieldwork conducted in the Aegean and on the islands of Chios and Lesbos. One of the main aims is to bring the figure of the migrant back into the study of border technologies. By combining insights from science and technology studies with border, mobility and security studies, the article distinguishes between processes of intervention, mobilization and realization and emphasizes the role of migrants in their encounter with surveillance operations. Two claims are brought forward. First, engaging with recent scholarly work on the visual politics of border surveillance, we circumscribe an ongoing 'transactional politics'. Second, the dynamic interplay between vision and action brings about a situation of 'recalcitrance', in which mobile objects and subjects of various kinds are drawn into securitized relations, for instance in encounters between coast guard boats and migrant boats at sea. Without reducing migrants to epiphenomena of those relations, this recalcitrance typifies the objects of surveillance as both relatable as well as resistant, particularly in the tensions between border control and search and rescue.

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

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A. Kiratzi

2002-06-01

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

Trace metal concentrations in marine organisms from the Eastern Aegean, Turkey

International Nuclear Information System (INIS)

Kucuksezgin, F.

1999-01-01

Monitoring of mercury, cadmium and lead levels in striped mullet (Mullus barbatus) was conducted in the Eastern Aegean over 3 year period and in some other species during 1996 in the framework of a National Marine Measurement Program and MED-POL II Project for the Aegean Sea. Of all the research on the concentrations of trace metals in the Aegean environment only a little has been carried out in that part of the Eastern Aegean

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

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Y. Altinok

2005-01-01

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

Hydrothermal influence on nearshore sediments of Kos Island, Aegean Sea

Science.gov (United States)

Megalovasilis, Pavlos; Godelitsas, Athanasios

2015-04-01

The Kos-Nisyros volcanic centre is a long-active, Plio-Pleistocene magmatic system in the subduction zone along the easternmost edge of the active Hellenic volcanic arc in the Aegean Sea. Although today there are signs of relative quiescence in volcanic activity, active onshore fumaroles and shallow-sea hydrothermal vents persist on, amongst others, the island of Kos. The present study explores the large-scale imprint of hydrothermally sourced heavy metals and nutrients on the island's coastal marine environment, based on geochemical data collected in September 2007 from hydrothermal waters and surficial nearshore sediments (Kos is severely influenced by ongoing submarine hydrothermal activity, and confirm that shallow-water sediment Fe, Mn, Zn and Pb levels are substantially higher than those of other islands along the Hellenic volcanic arc, and even exceed those of some deep-water hydrothermal vents in other world regions. Evidently, there may be significant metallic sulphide deposits of hydrothermal origin at depth beneath Kos.

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

International Nuclear Information System (INIS)

Pippos, H.S.

1984-10-01

The present report deals with the geological, technical and statistical data of the car-borne scintillometer survey (4,750.7 km) of 38 islands and of the on foot radiometry (87.5 km) of 13 islands of the Aegean Sea. Sixty-nine map sheets (scale 1:50,000) have been covered, corresponding to the total surveyed area of 9,464 km 2 . (author)

Natural radioactivity in environmental samples from an island of volcanic origin (Milos, Aegean Sea)

International Nuclear Information System (INIS)

Florou, H.; Kritidis, P.

1991-01-01

Enhanced concentrations of natural radionuclides occur in volcanic islands such as Milos in the Aegean Sea. The natural gamma radiation status of the entire environment in Milos were studied using gamma radiometry. Gamma spectrometry was used to analyse ore samples, sediments and marine biota. While non-living materials showed enhanced levels of natural radioactivity, most of the marine organisms examined did not seem to reflect this radiological status. (UK)

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

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Bulatović Aleksandar

2011-01-01

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

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

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A. SIOULAS

2000-12-01

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

Assembling Ecological Pieces to Reconstruct the Conservation Puzzle of the Aegean Sea

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Maria Sini

2017-11-01

Full Text Available The effective conservation of marine biodiversity through an integrated ecosystem-based management approach requires a sound knowledge of the spatial distribution of habitats and species. Although costly in terms of time and resources, acquiring such information is essential for the development of rigorous management plans and the meaningful prioritization of conservation actions. Located in the northeastern part of the Mediterranean, the Aegean Sea represents a stronghold for marine biodiversity. However, conservation efforts are hampered by the apparent lack of spatial information regarding marine habitats and species. This work is the first to address this knowledge gap by assembling, updating, and mapping information on the distribution of key ecological components. A range of data sources and methodological approaches was utilized to compile and complement the available data on 68 ecological features of conservation interest (58 animal species, six habitat categories, and four other vulnerable ecological features. A standardized data evaluation procedure was applied, based on five semi-quantitative data quality indicators in the form of a pedigree matrix. This approach assessed the sufficiency of the datasets and allowed the identification of the main sources of uncertainty, highlighting aspects that require further investigation. The overall dataset was found to be sufficient in terms of reliability and spatiotemporal relevance. However, it lacked in completeness, showing that there are still large areas of the Aegean that remain understudied, while further research is needed to elucidate the distribution patterns and conservation status of several ecological features; especially the less charismatic ones and those found in waters deeper than 40 m. Moreover, existing conservation measures appear to be inadequate to safeguard biodiversity. Only 2.3% of the study area corresponds to designated areas for conservation, while 41 of the

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

Science.gov (United States)

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

2017-03-01

The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) - a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29-87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant effort, financial resources and policies/regulation in order to protect/maintain the critical economic resource of the Aegean archipelago.

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

NARCIS (Netherlands)

Klaver, M.; Djuly, T.; de Graaf, S.; Sakes, A.; Wijbrans, J.R.; Davies, G.R.; Vroon, P.Z.

2015-01-01

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

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

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J. CASTRITSI-CATHARIOS

2011-01-01

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

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)

Tsytsugina, V.G.

1991-01-01

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)

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

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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.

Additional Records of Two Rare Crabs, Ilia nucleus (Linnaeus, 1758 and Ethusa mascarone (Herbst, 1785 from Izmir Bay, Aegean Sea, Turkey

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Okan AKYOL

2016-11-01

Full Text Available One specimen of Ilia nucleus and one specimen of Ethusa mascarone were collected from Urla coasts, Izmir Bay, Aegean Sea. Up to now, both rare species are being reported for the three and four times from Izmir Bay, respectively.

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,...

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

Data.gov (United States)

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

Ambient noise levels and characterization in Aegean region, Turkey

Science.gov (United States)

Sevim, Fatih; Zor, Ekrem; Açıkgöz, Cem; Tarancıoğlu, Adil

2018-03-01

We assessed the ambient noise level in the Aegean region and analyzed its diurnal variation and its relation to the earthquake detection capability of the Aegean Region Seismic Network (ARSN). We prepared probability density functions (PDFs) for 19 broadband stations in the Aegean region operated by the Earth and Marine Sciences Institute (EMSI) of the Marmara Research Center (MRC) of the Turkish Scientific Research Council (TÜBİTAK). The power spectral densities (PSDs) used to construct PDFs for each station were computed for the periods between 0.02 and 180 s. In addition, we generated noise map of the Aegean region for different periods using the PDFs to assess the origin of the noise. We analyzed earthquake activity in the region and found that there are more local events recorded at night than during the day for each station. This difference is strongly related to diurnal variation of background noise level for the period range mostly covering the frequency range for the local events. We observed daytime noise level 15 to 20 dB higher than that at the nighttime in high frequencies for almost all stations caused by its proximity to settled areas and roads. Additionally, we observed a splitting peak within the Double Frequency (DF) microseism band; it showed a clear noise increase around the short period DF band at all the stations, decreasing inland. This peak may be related to sea waves locally generated in the Aegean Sea. We also identified a prominent increase related to marble saw companies in some stations' noise PDFs.

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

Science.gov (United States)

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

2017-04-01

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

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,...

Homogenous stretching or detachment faulting? Which process is primarily extending the Aegean crust

Science.gov (United States)

Kumerics, C.; Ring, U.

2003-04-01

In extending orogens like the Aegean Sea of Greece and the Basin-and-Range province of the western United States, knowledge of rates of tectonic processes are important for understanding which process is primarily extending the crust. Platt et al. (1998) proposed that homogeneous stretching of the lithosphere (i.e. vertical ductile thinning associated with a subhorizontal foliation) at rates of 4-5 km Myr-1 is the dominant process that formed the Alboran Sea in the western Mediterranean. The Aegean Sea in the eastern Mediterranean is well-known for its low-angle normal faults (detachments) (Lister et al., 1984; Lister &Forster, 1996) suggesting that detachment faulting may have been the primary agent achieving ~>250 km (McKenzie, 1978) of extension since the Miocene. Ring et al. (2003) provided evidence for a very fast-slipping detachment on the islands of Syros and Tinos in the western Cyclades, which suggests that normal faulting was the dominant tectonic process that formed the Aegean Sea. However, most extensional detachments in the Aegean do not allow to quantify the amount of vertical ductile thinning associated with extension and therefore a full evaluation of the significance of vertical ductile thinning is not possible. On the Island of Ikaria in the eastern Aegean Sea, a subhorizontal extensional ductile shear zone is well exposed. We studied this shear zone in detail to quantify the amount of vertical ductile thinning associated with extension. Numerous studies have shown that natural shear zones usually deviate significantly from progressive simple shear and are characterized by pronounced shortening perpendicular to the shear zone. Numerous deformed pegmatitic veins in this shear zone on Ikaria allow the reconstruction of deformation and flow parameters (Passchier, 1990), which are necessary for quantifying the amount of vertical ductile thinning in the shear zone. Furthermore, a flow-path and finite-strain study in a syn-tectonic granite, which

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

Science.gov (United States)

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

2015-04-01

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

Partial pressure (or fugacity) of carbon dioxide and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer and other instruments from POLARSTERN in the Adriatic Sea, Aegean Sea and others from 2014-03-09 to 2015-01-31 (NCEI Accession 0160489)

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National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0160489 includes Surface underway, chemical and meteorological data collected from POLARSTERN in the Adriatic Sea, Aegean Sea, Alboran Sea, Arabian...

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)

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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,...

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

Directory of Open Access Journals (Sweden)

M.V. TRIANTAPHYLLOU

2009-12-01

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

Decapod crustaceans on the Gökçeada (Imbros island continental shelf (north-eastern Aegean Sea

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A.S. ATES

2006-12-01

Full Text Available The present composition of decapod crustaceans found at the sublittoral depths (5-104 m off the coast of the island of Gökçeada (north-eastern Aegean Sea is presented. A total of 28 species (11 caridean shrimps, 1 thalassinid ghost crab, 7 anomurans and 9 brachyuran crabs and 277 specimens were recorded. The caridean shrimp, Athanas nitescens had the highest abundance with a dominance value of 20.94% in samples. The dominant group is caridean, represented by a total of 11 species and an occurrence frequency of 39.29%.

Research on a dispersing solution for burnt crude oils: Aegean Sea oil spill

International Nuclear Information System (INIS)

Bergueiro, J.R.; Morales, N.; Dominguez, F.

1993-01-01

The oil tanker Aegean Sea spilled oil when it grounded during severe storm conditions near La Coruna, Spain. Much of the oil burned after an explosion was caused by the hull breaking apart. Oil which contaminated several beaches was affected by both combustion and weathering. Experiments were conducted on oil sampled from the beaches to investigate dispersion of the oil using Beep Enersperse 1990 at different shaking speeds. Biodegradation experiments were also conducted in the presence of Beep Enersperse 1990 but with seawater absent. Although emulsification of the burnt and weathered oil was very difficult, good dispersion and biodegradation were obtained. After 42 d in a stirred reactor, biodegradation of the oil reached at least 80%. 3 refs., 3 figs., 4 tabs

Magma evolution in the Pliocene Pleistocene succession of Kos, South Aegean arc (Greece)

Science.gov (United States)

Pe-Piper, Georgia; Moulton, Ben

2008-11-01

This study investigates the petrogenesis of Pliocene-Quaternary andesites, dacites and rhyolites of the island of Kos. These volcanic rocks differ from other volcanic centres in the South Aegean arc in the narrow range of Pliocene volcanic products, the abundance of high-silica rhyolite, the lower ɛNd for a given Sr isotope composition, and greater depth to the subducting slab. Pliocene and early Pleistocene dacite stocks and rhyolite domes are succeeded by younger tuffs, notably the 0.16 Ma Kos Plateau Tuff derived from a super-eruption of an andesite stratocone now subsided beneath the sea south of Kos. Volcanic products in tuffs have been sampled from lithic clasts. Andesite, dacite and rhyolite all have ɛNd ˜+ 1.5 to -1.5 and 86Sr/ 87Sr ˜ 0.7042; this unusual composition is argued to be the result of subduction of sediments derived from the River Nile. All rock types show structures indicative of widespread magma mixing, including complexly zoned plagioclase, clinopyroxene and amphibole containing glass inclusions of trachyte and rhyolite compositions. The observed rocks result from fractionation and mixing of three principal magma types: (a) calc-alkaline high-Al basalt that fractionated to andesite at the base of crust; (b) partially melted metabasaltic amphibolite underplated at the base of crust, that fractionated to produce high-SiO 2 rhyolite; and (c) a minor component of trachytic magma from partial melting of enriched subcontinental lithospheric mantle. The complexly zoned phenocrysts with glass inclusions provide specific evidence for mixing of these three components. Specifically, it was the emplacement of the andesite into a voluminous rhyolite magma in a mid-crustal magma chamber that led to the explosive Kos Plateau Tuff super-eruption.

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.

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 * Air borne measurements * Marine Atmospheric Boundary Layer * Turbulent fluxes * Gas and aerosol composition * Etesian winds Subject RIV: EH - Ecology, Behaviour Impact factor: 3.976, year: 2015

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

South China Sea

Science.gov (United States)

Morton, Brian; Blackmore, Graham

2001-01-01

The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

Partial pressure (or fugacity) of carbon dioxide, temperature, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer and other instruments from unknown platforms in the Adriatic Sea, Aegean Sea and others from 2012-01-01 to 2012-12-31 (NODC Accession 0059946)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0059946 includes Surface underway, chemical, meteorological and physical data collected from unknown platforms in the Adriatic Sea, Aegean Sea,...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer and other instruments from Celebrity Equinox in the Adriatic Sea, Aegean Sea and others from 2016-01-02 to 2017-01-02 (NCEI Accession 0157264)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157264 includes Surface underway, chemical, meteorological and physical data collected from Celebrity Equinox in the Adriatic Sea, Aegean Sea,...

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

Directory of Open Access Journals (Sweden)

Takvor Soukissian

2017-03-01

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

South Aegean volcanic glass. Separation and analysis by INAA and EPMA

International Nuclear Information System (INIS)

Saminger, S.; Peltz, C.; Bichler, M.

2000-01-01

Pumice from the major volcanic sources (Milos, Nisyros, Yali, Kos and Santorini) in the South Aegean region was investigated to reveal the differences between the composition of the bulk material, which contains a certain percentage of crystallites, and the pure glass phase, which is the main constituent. The knowledge of these differences is important for the identification of vitric tephra layers found in the Eastern Mediterranean region in archaeological context, in deep sea drilling cores and lake sediments. Eruption products, deposited at some distance, show not only a decrease in their grain size, but also have usually lost their crystalline fraction due to gravity separation and consist only of glass shards. Major element distributions in such layers and in pumiceous glass are not sufficient for a reliable identification of the volcanic source, as several eruptions are known to have produced chemically very similar tephra layers in this region. Trace element data, especially of the rather immobile rare earth elements (REEs), can provide greater information on tephra originating from different volcanic eruptions. Therefore, a technique has been developed to separate the glass phase from different primary pumices to reveal differences in their trace element distributions. The concentrations of the major constituents, in particular Al, Ca, Fe, Mg, Mn, Na, Si, and Ti were determined by electron probe microanalysis (EPMA), those of Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Th, Ti, U, V, Yb and Zr by instrumental neutron activation analysis. Subtle differences between the compositions of the glass phase and the bulk material are explained by differentiation during partial crystallization. Their applicability to the classification of tephra layers is demonstrated. (author)

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

Science.gov (United States)

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

2016-10-01

Marine sediment samples were collected from Ierissos Gulf, N Aegean Sea, close to the coastal mining facilities. Measurements of radionuclide and metal concentrations, mineral composition and grain size distribution were performed. The concentrations of (226)Ra, (235)U and trace metals showed enhanced values in the port of Stratoni compared with those obtained near to Ierissos port. The dose rates received by marine biota were also calculated by the ERICA Assessment Tool and the results indicated no significant radiological risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Insights into the benthic communities response to the inflow of Black Sea mesotrophic waters in the North Aegean Sea

Science.gov (United States)

Lampadariou, Nikolaos; Sevastou, Katerina; Podaras, Dimitrios; Tselepides, Anastasios

2017-10-01

The effects of the Dardanelles inflow of buoyant, modified Black Sea waters (BSW) of low salinity and temperature, on the meio- and macrobenthic communities of the north Aegean ecosystem was investigated during two cruises in October 2013 and March 2014. Sediment samples were collected from two stations subjected to the BSW effect, one shallow and one deep north of the Dardanelles Straits, and from two stations of similar bathymetry, which were considered to be outside the influence of BSW and were located to the south of the Dardanelles Straits. Results suggest that there is an effect of the BSW on benthos, as both meiofaunal and macrofaunal standing stocks were lower at the most distant, and therefore least affected from the inflow, station, and higher at the station of similar bathymetry which was affected the most by the BSW inflow. Univariate and multivariate non-parametric analyses (nMDS, PERMANOVA) provided further support, indicating differences between the two areas (North vs. South) in the case of the deep stations, while differences between depth categories were evident in the area outside the BSW influence zone. Distance-based linear modeling (DISTLM) indicated that meiofauna correlated with proxies of food availability and sediment characteristics. Macrofauna, on the other hand, showed a rather high significant correlation with depth only. Nematode species composition was statistically significant different between depth categories only, yet the nMDS ordination clearly separated the deep southern station from the rest, with non-selective deposit feeders dominating the stations under the influence of the BSW, and epistratum feeders being important at the stations outside the influence of the BSW. It is concluded that both the meiofaunal and macrofaunal communities at the northern stations benefit from a constant input of high amounts of organic matter to the seafloor, while those at the southern area may be occasionally affected by the thermohaline BSW

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)

Mat Çatal, Ebru; Uğur, Aysun; Özden, Banu; Filizok, Işık

2012-01-01

In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210 Po, in the marine environment. 210 Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210 Po and 210 Pb 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 210 Po and 210 Pb content. The 210 Po and 210 Pb 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 210 Po and 210 Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210 Po to humans was calculated to be 10,530 μSv year −1 .

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 -...

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

Science.gov (United States)

2000-06-02

XI WOCSDICE 2000 Aegean Sea. Greece May 29 - June 02. 2000 Prof. Elias Muiioz Universita Politecnica de Madrid ETSI Telecomunicacion , IEL...Beaumont", and P. Gibart" ’lEL, ETSl Telecomunicacion , Univ. Politecnica de Madrid, Ciudad Universitaria, 28040-Madrid, Spain 2CNRS-CRHEA, Pare Sophia...Gibart2 ’IEL, ETS1 Telecomunicacion , Univ. Politecnica de Madrid, Ciudad Universitaria, 28040-Madrid, Spain 2CNRS-CRHEA, Pare Sophia Antipolis

Comparison of hypocentre parameters of earthquakes in the Aegean region

Science.gov (United States)

Özel, Nurcan M.; Shapira, Avi; Harris, James

2007-06-01

The Aegean Sea is one of the more seismically active areas in the Euro-Mediterranean region. The seismic activity in the Aegean Sea is monitored by a number of local agencies that contribute their data to the International Seismological Centre (ISC). Consequently, the ISC Bulletin may serve as a reliable reference for assessing the capabilities of local agencies to monitor moderate and low magnitude earthquakes. We have compared bulletins of the Kandilli Observatory and Earthquake Research Institute (KOERI) and the ISC, for the period 1976-2003 that comprises the most complete data sets for both KOERI and ISC. The selected study area is the East Aegean Sea and West Turkey, bounded by latitude 35-41°N and by longitude 24-29°E. The total number of events known to occur in this area, during 1976-2003 is about 41,638. Seventy-two percent of those earthquakes were located by ISC and 75% were located by KOERI. As expected, epicentre location discrepancy between ISC and KOERI solutions are larger as we move away from the KOERI seismic network. Out of the 22,066 earthquakes located by both ISC and KOERI, only 4% show a difference of 50 km or more. About 140 earthquakes show a discrepancy of more than 100 km. Focal Depth determinations differ mainly in the subduction zone along the Hellenic arc. Less than 2% of the events differ in their focal depth by more than 25 km. Yet, the location solutions of about 30 events differ by more than 100 km. Almost a quarter of the events listed in the ISC Bulletin are missed by KOERI, most of them occurring off the coast of Turkey, in the East Aegean. Based on the frequency-magnitude distributions, the KOERI Bulletin is complete for earthquakes with duration magnitudes Md > 2.7 (both located and assigned magnitudes) where as the threshold magnitude for events with location and magnitude determinations by ISC is mb > 4.0. KOERI magnitudes seem to be poorly correlated with ISC magnitudes suggesting relatively high uncertainty in the

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

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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.

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

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

2017-04-01

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

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

Partial pressure (or fugacity) of carbon dioxide, temperature, 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 AEGAEO in the Aegean Sea and Mediterranean Sea from 2006-02-08 to 2006-02-13 (NODC Accession 0084543)

Data.gov (United States)

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

Deep-sea geohazards in the South China Sea

Science.gov (United States)

Wu, Shiguo; Wang, Dawei; Völker, David

2018-02-01

Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods. These features include submarine landslides, pockmark fields, shallow free gas, gas hydrates, mud diapirs and earthquake tsunami, which are widely distributed in the continental slope and reefal islands of the South China Sea. Although the study and assessment of geohazards in the South China Sea came into operation only recently, advances in various aspects are evolving at full speed to comply with National Marine Strategy and `the Belt and Road' Policy. The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances. This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.

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

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A. GIANNAKOUROU

2014-12-01

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

Comparative distribution of the fan mussel Atrina fragilis (Bivalvia, Pinnidae in protected and trawled areas of the north Aegean Sea (Thermaikos Gulf

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K. FRYGANIOTIS

2013-02-01

Full Text Available The distribution of the fan mussel Atrina fragilis was studied at two contrasting areas of the north Aegean Sea (Thermaikos Gulf: one routinely trawled and one closed to trawlers for over 25 years. Significant differences were detected between the two areas with decreased values in density and size of A. fragilis individuals at the trawled area. As habitat differences, i.e. sediment composition and bathymetry, had non-significant effect, extensive trawling activities probably explain the observed results.

The Aegean Sea incident: A quantitative evaluation of the fate of the oil

International Nuclear Information System (INIS)

Bergueiro Lopez, J.R.; Morales Correas, N.; Dominguez Laseca, F.

1993-01-01

In December 1992, the tanker Aegean Sea was shipwrecked at the entrance to a harbor in northwest Spain. The accident was partly due to bad weather conditions and possibly also to the poor condition of the ship, which subsequently broke in two and caught fire. The tanker was carrying 79,000 tons of low-viscosity light oil, of which 40-60% burned. The oil slick coming from the wrecked ship spread westward and northward into nearby bays, impacting 100-200 km of coast with varying degrees of severity. Strong winds and stormy sea conditions at the time of the incident favored evaporation and natural dispersion of much of the spilled oil. Spill response and countermeasures included restriction of fishing zones, manual and mechanical cleaning of beaches and nearby rocks, use of pumps and skimmers to recover oil from water and shore, and stirring oil-penetrated sand to ca 50 cm depth to facilitate oxygenation and ensure degradation of oil traces. About 6,000 m 3 of emulsified oil were collected from the water and another 1,000 m 3 from the shore; 5,000-6,000 tons of unspilled oil was recovered from the tanker. A simulation model estimated that if no burning had occurred, 2/3 of the oil would have dispersed in the sea or evaporated into the air in ca 3 d. Ecological impacts on plankton, benthos, and pelagic and bird communities appears to have been minor or at least relatively localized. Long-term ecological impacts are being studied. However, zones of fish/shellfish breeding were affected, with short-term damages estimated at over $45 million. 9 refs., 5 figs., 1 tab

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

International Nuclear Information System (INIS)

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

2016-01-01

Marine sediment samples were collected from Ierissos Gulf, N Aegean Sea, close to the coastal mining facilities. Measurements of radionuclide and metal concentrations, mineral composition and grain size distribution were performed. The concentrations of "2"2"6Ra, "2"3"5U and trace metals showed enhanced values in the port of Stratoni compared with those obtained near to Ierissos port. The dose rates received by marine biota were also calculated by the ERICA Assessment Tool and the results indicated no significant radiological risk. - Highlights: • Baseline information of radionuclides in a coastal area near a mining site. • Trace metals measurements in marine sediment. • Dose rates assessment for marine biota using ERICA Assessment Tool.

210Po activity concentrations in mussels at Aegean Turkish Coast

International Nuclear Information System (INIS)

Sekkin, F.; Tanbay, A.; Vener, V.

2000-01-01

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 210 Po and 210 Pb 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 210 Po 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 210 Po food-chain transfer. (author)

Impact of the Aegean Sea oil spill on the subtidal fine sand macrobenthic community of the Ares-Betanzos Ria (Northwest Spain)

International Nuclear Information System (INIS)

Gomez Gesteira, J.L.; Dauvin, J.C.

2005-01-01

Two sites located in the sublittoral fine-sand macrobenthic community of the Ares-Betanzos Ria were sampled over four years (December 1992-November 1996) in the wake of the Aegean Sea oil spill. This sampling revealed that the petroleum had affected the structure and abundance of this community, as well as the number of taxa present. In this context, the results of the biotic index and the biotic coefficient were insufficient; however, study of the synthetic parameters, particularly through multivariate analysis, showed that the community went through three successive and distinct phases over time. A short period of high mortality in some species, especially amphipods, was followed by a period of low abundance that lasted until the spring of 1995. A period of recovery began in the second half of 1995 and continued through to the end of 1996, when the survey ended. The community showed a gradual evolution back towards the conditions observed immediately after the spill, when abundance of the more resistant species was still high. Despite this similarity, the last period exhibits a new structure, clearly separate from the two previous periods. This study provides information about the short-term effects of the Aegean Sea oil spill on the fine sand bottoms of the sites surveyed in the Ares-Betanzos Ria. This information could also serve as a baseline for identifying the effects of a more recent accident, the Prestige oil spill, in which similar communities in other Galician rias were polluted in 2002-2003. (author)

Coastal habitat mapping in the Aegean Sea using high resolution orthophoto maps

Science.gov (United States)

Topouzelis, Konstantinos; Papakonstantinou, Apostolos; Doukari, Michaela; Stamatis, Panagiotis; Makri, Despina; Katsanevakis, Stelios

2017-09-01

The significance of coastal habitat mapping lies in the need to prevent from anthropogenic interventions and other factors. Until 2015, Landsat-8 (30m) imagery were used as medium spatial resolution satellite imagery. So far, Sentinel-2 satellite imagery is very useful for more detailed regional scale mapping. However, the use of high resolution orthophoto maps, which are determined from UAV data, is expected to improve the mapping accuracy. This is due to small spatial resolution of the orthophoto maps (30 cm). This paper outlines the integration of UAS for data acquisition and Structure from Motion (SfM) pipeline for the visualization of selected coastal areas in the Aegean Sea. Additionally, the produced orthophoto maps analyzed through an object-based image analysis (OBIA) and nearest-neighbor classification for mapping the coastal habitats. Classification classes included the main general habitat types, i.e. seagrass, soft bottom, and hard bottom The developed methodology applied at the Koumbara beach (Ios Island - Greece). Results showed that UAS's data revealed the sub-bottom complexity in large shallow areas since they provide such information in the spatial resolution that permits the mapping of seagrass meadows with extreme detail. The produced habitat vectors are ideal as reference data for studies with satellite data of lower spatial resolution.

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

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F. SAKELLARIADOU

2006-12-01

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.

Crust Structure Data of Seas Surrounding Turkey

International Nuclear Information System (INIS)

Maden, N.; Gelisli, K.

2007-01-01

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

South China Sea Dispute

OpenAIRE

Tanderup, Kasper Buch; Grinderslev, Emil Juhler; Tønnesen-Højbjerg, Asser Laurits Svend

2017-01-01

China is rising rapidly in terms of economics, military spending, sphere of influence and claims to in their view former territory. This paper has aimed to discuss the latter through analysis of the present dispute concerning islands and maritime territory in the South China Sea. The Chinese have become increasingly assertive in their claims formulated through a U-shaped line entailing most of the area within the South China Sea. The claims are contested by Vietnam, the Philippines, Indonesia...

Geometry of the Aegean Benioff zones

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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.

Petroleum in the South China Sea : a Chinese national interest

OpenAIRE

Snildal, Knut

2000-01-01

The thesis analyses the relationship between China's petroleum policies and China's involvement in the South China Sea conflict. The aim of the thesis is to determine what China's national interest are in the South China Sea, and to detect who forms, and how, China's South China Sea policy. The thesis discusses whether China's assumed interest in the South China Sea of exploiting the petroleum reserves of the territorially disputed areas of the South China Sea is a short-term national interes...

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

International Nuclear Information System (INIS)

Danali-Cotsaki, S.; Liritzis, Y.

1988-01-01

The effective doses in fish from the Aegean Sea were calculated for the nuclide 137 Cs 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

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

International Nuclear Information System (INIS)

Florou, H.; Catsiki, A.B.; Papaefthymiou, H.; Chaloulou, Ch.

2004-01-01

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

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

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Athanassios C. Tsikliras

2015-04-01

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

Plant speciation in continental island floras as exemplified by Nigella in the Aegean Archipelago

OpenAIRE

Comes, Hans Peter; Tribsch, Andreas; Bittkau, Christiane

2008-01-01

Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times (ca

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

Science.gov (United States)

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

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

Viability and Management Targets of Mediterranean Demersal Fisheries: The Case of the Aegean Sea.

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George Tserpes

Full Text Available Management of the Mediterranean demersal stocks has proven challenging mainly due to the multi-species character of the fisheries. In the present work, we focus on the multi-species demersal fisheries of the Aegean Sea (eastern Mediterranean aiming to study the effects of different management measures on the main commercial stocks, as well as to explore the economic viability of the fisheries depending upon these resources, by means of simulated projections. Utilizing the limited available data, our results demonstrated that, under the current exploitation pattern, the economic viability of the fleets is threatened, particularly if fuel prices increase. Additionally, the biological targets set for the most exploited species, such as hake, will not be met under the current management regime. The projections also showed that the only management scenario under which both resource sustainability and economic viability of the fisheries are ensured is the decrease of fleet capacity in terms of vessel numbers. In this case, however, measures to support the fisheries-dependent communities need to be implemented to prevent the collapse of local economies due to employment decrease. Scenarios assuming selectivity improvements would be also beneficial for the stocks but they showed low economic performance and their application would threaten the viability of the fleets, particularly that of the trawlers.

Determination of arsenic species in seafood samples from the Aegean Sea by liquid chromatography-(photo-oxidation)-hydride generation-atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, Richard [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Soeroes, Csilla [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Ipolyi, Ildiko [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Fodor, Peter [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Thomaidis, Nikolaos S. [Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistiomopolis Zografou, 15776 Athens (Greece)]. E-mail: ntho@chem.uoa.gr

2005-08-15

In this study arsenic compounds were determined in mussels (Mytulis galloprovincialis), anchovies (Engraulis encrasicholus), sea-breams (Sparus aurata), sea bass (Dicentrarchus labrax) and sardines (Sardina pilchardus) collected from Aegean Sea using liquid chromatography-photo-oxidation-hydride generation-atomic fluorescence spectrometry [LC-(PO)-HG-AFS] system. Twelve arsenicals were separated and determined on the basis of their difference in two properties: (i) the pK {sub a} values and (ii) hydride generation capacity. The separation was carried out both with an anion- and a cation-exchange column, with and without photo-oxidation. In all the samples arsenobetaine, AB was detected as the major compound (concentrations ranging between 2.7 and 23.1 {mu}g g{sup -1} dry weight), with trace amounts of arsenite, As(III), dimethylarsinic acid, DMA and arsenocholine, AC, also present. Arsenosugars were detected only in the mussel samples (in concentrations of 0.9-3.6 {mu}g g{sup -1} dry weight), along with the presence of an unknown compound, which, based on its retention time on the anion-exchange column Hamilton PRP-X100 and a recent communication [E. Schmeisser, R. Raml, K.A. Francesconi, D. Kuehnelt, A. Lindberg, Cs. Soeroes, W. Goessler, Chem. Commun. 16 (2004) 1824], is supposed to be a thio-arsenic analogue.

Sea Surface Temperature and Ocean Color Variability in the South China Sea

Science.gov (United States)

Conaty, A. P.

2001-12-01

The South China Sea is a marginal sea in the Southeast Asian region whose surface circulation is driven by monsoons and whose surface currents have complex seasonal patterns. Its rich natural resources and strategic location have made its small islands areas of political dispute among the neighboring nations. This study aims to show the seasonal and interannual variability of sea surface temperature and ocean color in South China Sea. It makes use of NOAA's Advanced Very High Resolution Radiometer (AVHRR) satellite data sets on sea surface temperature for the period 1981-2000 and NASA's Nimbus-7 Coastal Zone Color Scanner (CZCS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite data sets on pigment concentration (ocean color) for the period 1981-1996 and 1997-2000, respectively. Transect lines were drawn along several potential hotspot areas to show the variability in sea surface temperature and pigment concentration through time. In-situ data on sea surface temperature along South China Sea were likewise plotted to see the variability with time. Higher seasonal variability in sea surface temperature was seen at higher latitudes. Interannual variability was within 1-3 Kelvin. In most areas, pigment concentration was higher during northern hemisphere winter and autumn, after the monsoon rains, with a maximum of 30 milligrams per cubic meter.

The advance of Kos Plateau Tuff ignimbrite into the marine realm of the Kalymnos Basin, SE Aegean Sea.

Science.gov (United States)

Markakis, Emmanouil; Anastasakis, George

2013-04-01

The 161 ka Kos Plateau Tuff (KPT) eruption is considered to be the largest explosive Quaternary event in the eastern Mediterranean. It produced pumice rafts followed by "non-welded ignimbrites" that are up to 30m thick, especially widespread on Kos island and covering an area of > 80 Km2 that includes mainly islands and present marine regions. Pyroclastic flows travelled from the proposed vent, that lies between and around Yali and Nisyros islands, across present land and sea, the total volume of the tuff has been estimated as at least 100km3. KPT products principally consist of rhyolitic ash and pumice. Post 2010 Athens University oceanographic missions have mapped the seafloor around the volcanic islands of the SE Aegean Sea. Here we present new data on seafloor morphology and Upper Quaternary seafloor stratigraphy of the Kalymnos basin that extends over an area over 70km2 and map the advance and deposition of the KPT that was previously unknown in this region. The Kalymnos basin is roughly triangular in shape and essentially consists of two sedimentation depocenters: a) a roughly elliptical 400 m deep northern segment that is developed sub-parallel to Kalymnos Island and its W-SW shelf; b) a rather physiographically complex western sector developed NE of Astipalea island and reaching depths of over 620m. High resolution sparker profiles from the west Kos-Kalymnos shelf reveal an outstanding seismic stratigraphy of stacked and prograded coastal clinoform packets capped by erosional transgressive surfaces that record Quaternary eustatic lowstands deposits of sea level with clinoforms developing during forced regression and the erosional surfaces during transgression. We show that a massive gravity flow deposit is intercalated with the shelf sediments. Above it low sea level MIS 6 and 2 sedimentary sequences are fully developed and below stage 8-10 sediments are erratically preserved over stages 12 and 16 sediments. This gravity flow deposit swept across the shelf

Countermeasure Study on Deep-sea Oil Exploitation in the South China Sea——A Comparison between Deep-sea Oil Exploitation in the South China Sea and the Gulf of Mexico

Science.gov (United States)

Zhao, Hui; Qiu, Weiting; Qu, Weilu

2018-02-01

The unpromising situation of terrestrial oil resources makes the deep-sea oil industry become an important development strategy. The South China Sea has a vast sea area with a wide distribution of oil and gas resources, but there is a phenomenon that exploration and census rates and oil exploitation are low. In order to solve the above problems, this article analyzes the geology, oil and gas exploration and exploration equipment in the South China Sea and the Gulf of Mexico. Comparing the political environment of China and the United States energy industry and the economic environment of oil companies, this article points out China’s deep-sea oil exploration and mining problems that may exist. Finally, the feasibility of oil exploration and exploitation in the South China Sea is put forward, which will provide reference to improve the conditions of oil exploration in the South China Sea and promoting the stable development of China’s oil industry.

The South Pole and the Ross Sea

Science.gov (United States)

2002-01-01

This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Investigating potential seismic hazard in the Gulf of Gökova (South Eastern Aegean Sea) deduced from recent shallow earthquake activity

Science.gov (United States)

Rontogianni, S.; Konstantinou, K. I.; Evangelidis, C.; Melis, N. S.

2011-12-01

The Gulf of Gökova is located in the southeast Aegean along the coast of the southwest Anatolia. It is surrounded by the Bodrum Peninsula to the north, Datça Peninsula to the south and the island of Kos to the west. The Gulf is under a N-S regional extensional tectonic regime related to the westerly escape of the Anatolian plate, as a result of the collision of the Arab-African and Eurasian plates. Multi-channel seismic reflection studies that took place in the area revealed a E-W trending buried listric normal fault to the south of the Gulf, the Datça Fault, the associated antithetic faults in the north of the Gulf and a younger NE active fault, named Gökova Tranfer Fault (GTF), in the central part of the Gulf. According to these studies, the activity of the Datça Fault has been decelerated, possibly since Pleistocene, while the continuing extension has been taken up by the faults in the northeast margin of the Gulf. For our analysis we selected all the shallow earthquake activity that took place in the Gulf, within the time window from 2002 to 2011 as provided by the two seismological centers NOA-IG (HL) and KOERI-NEMC (KO). We used data from 15 three component seismic stations surrounding the Gulf. This seismic activity is observed within three periods: (a) November 2002 - May 2003, (b) May 2004 - end of 2007 and (c) December 2008 - May 2011. The strongest events recorded took place in January 2005 and May 2011, with local magnitudes ML 5.1 and 4.9 respectively. After a thorough quality control, a dataset of 192 seismic events was selected, with criteria that at least 4P and 3S phases were available. Manually picked arrival times for these selected events were inverted in order to obtain a 1D velocity model with station corrections. Probabilistic nonlinear earthquake locations were calculated using this newly derived velocity model. The earthquake locations showed that the seismic activity extends from the island of Kos to the center of the Gulf, mainly

Phytoplankton variability and community structure in relation to hydrographic features in the NE Aegean frontal area (NE Mediterranean Sea)

Science.gov (United States)

Lagaria, A.; Mandalakis, M.; Mara, P.; Frangoulis, C.; Karatsolis, B.-Th.; Pitta, P.; Triantaphyllou, M.; Tsiola, A.; Psarra, S.

2017-10-01

The structure of phytoplankton community in the salinity-stratified Northeastern Aegean frontal area adjacent to the Dardanelles Straits was investigated on a seasonal basis (autumn, spring and summer) and in relation to circulating water masses: the modified Black Sea Water (BSW) and the Levantine Water (LW). By employing High Performance Liquid Chromatography (HPLC) for the analysis of phytoplankton pigments in conjunction with conventional cell counting methodologies (i.e. inverted light microscopy, flow cytometry) and primary production measurements, a comprehensive qualitative and quantitative characterization of phytoplankton community composition and its activity was conducted. Chlorophyll-a normalized production and estimated growth rates presented the highest values within the 'fresh' BSW mass during summer, though generally growth rates were low (production. Large cell organisms, and in particular diatoms, were closely associated with the surface BSW masses outflowing from the Straits. Our results showed that all phytoplankton size components were significant over time and space suggesting a rather multivorous food web functioning of the system.

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

Energy Technology Data Exchange (ETDEWEB)

Danali-Cotsaki, S; Liritzis, Y

1988-02-15

The effective doses in fish from the Aegean Sea were calculated for the nuclide /sup 137/Cs covering the period 1975-1982. The effective dose varies between 3x10/sup -5/ and 10x10/sup -5/ mSv y/sup -1/ for adults and 14x10/sup -5/ to 56x10/sup -5/ y/sup -1/ for children, while the cumulative effective dose for the period 1975-1982 equals to 40.86x10/sup -5/ and 229.57x10/sup -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.

Is South China Sea the new 'inalienable' part of China?

OpenAIRE

Jash, Amrita

2016-01-01

China’s growing military posture and unilateral behavior in South China Sea has raised red alarms in international politics, vehemently challenging the existing status quo. What is apparent is that China’s uncompromising attitude in the South China Sea presents China’s obsession over its territorial claims, wherein, South China Sea can be called the ‘new inalienable part’ of China.

Seasonal variations in dissolved organic matter composition using absorbance and fluorescence spectroscopy in the Dardanelles Straits - North Aegean Sea mixing zone

Science.gov (United States)

Pitta, Elli; Zeri, Christina; Tzortziou, Maria; Mousdis, George; Scoullos, Michael

2017-10-01

The Dardanelles Straits - North Aegean Sea mixing zone is the area where the less saline waters of Black Sea origin supply organic material to the oligotrophic Mediterranean Sea. The objective of this work was to assess the seasonal dynamics of dissolved organic matter (DOM) in this region based on the optical properties (absorbance and fluorescence). By combining excitation-emission fluorescence with parallel factor analysis (EEM-PARAFAC), four fluorescent components were identified corresponding to three humic - like components and one amino acid - like. The latter was dominant during all seasons. Chromophoric DOM (CDOM) and dissolved organic carbon (DOC) were found to be strongly coupled only in early spring when conservative conditions prevailed and the two water masses present (Black Sea Waters - BSW and Levantine Waters - LW) could be identified by their absorption coefficients (a300) and spectral slopes S275-295. In summer and autumn the relationships collapsed. During summer two features appear to dominate the dynamics of CDOM: i) photodegradation that acts as an important sink for both the absorbing DOM and the terrestrially derived fluorescent humic substances and ii) the release of marine humic like fluorescent substances from bacterial transformation of DOM. Autumn results revealed a source of fluorescent CDOM of high molecular weight, which was independent of water mass sources and related to particle and sedimentary processes. The removal of the amino acid-like fluorescence during autumn provided evidence that although DOC was found to accumulate under low inorganic nutrient conditions, dissolved organic nitrogenous compounds could serve as bacterial substrate.

Evidence of extensional and strike-slip deformation in the offshore Gökova-Kos area affected by the July 2017 Mw6.6 Bodrum-Kos earthquake, eastern Aegean Sea

Science.gov (United States)

Ocakoğlu, Neslihan; Nomikou, Paraskevi; İşcan, Yeliz; Loreto, Maria Filomena; Lampridou, Danai

2018-01-01

The interpretation of new multichannel seismic profiles and previously published high-resolution swath and seismic reflection data from the Gökova Gulf and southeast of Kos Island in the eastern Aegean Sea revealed new morphotectonic features related to the July 20, 2017 Mw6.6 Bodrum-Kos earthquake offshore between Kos Island and the Bodrum Peninsula. The seafloor morphology in the northern part of the gulf is characterized by south-dipping E-W-oriented listric normal faults. These faults bend to a ENE-WSW direction towards Kos Island, and then extend parallel to the southern coastline. A left-lateral SW-NE strike-slip fault zone is mapped with segments crossing the Gökova Gulf from its northern part to south of Kos Island. This fault zone intersects and displaces the deep basins in the gulf. The basins are thus interpreted as the youngest deformed features in the study area. The strike-slip faults also produce E-W-oriented ridges between the basin segments, and the ridge-related vertical faults are interpreted as reverse faults. This offshore study reveals that the normal and strike-slip faults are well correlated with the focal mechanism solutions of the recent earthquake and general seismicity of the Gökova Gulf. Although the complex morphotectonic features could suggest that the area is under a transtensional regime, kinematic elements normally associated with a transtensional system are missing. At present, the Gökova Gulf is experiencing strike-slip motion with dominant extensional deformation, rather than transtensional deformation.

Evidence of extensional and strike-slip deformation in the offshore Gökova-Kos area affected by the July 2017 Mw6.6 Bodrum-Kos earthquake, eastern Aegean Sea

Science.gov (United States)

Ocakoğlu, Neslihan; Nomikou, Paraskevi; İşcan, Yeliz; Loreto, Maria Filomena; Lampridou, Danai

2018-06-01

The interpretation of new multichannel seismic profiles and previously published high-resolution swath and seismic reflection data from the Gökova Gulf and southeast of Kos Island in the eastern Aegean Sea revealed new morphotectonic features related to the July 20, 2017 Mw6.6 Bodrum-Kos earthquake offshore between Kos Island and the Bodrum Peninsula. The seafloor morphology in the northern part of the gulf is characterized by south-dipping E-W-oriented listric normal faults. These faults bend to a ENE-WSW direction towards Kos Island, and then extend parallel to the southern coastline. A left-lateral SW-NE strike-slip fault zone is mapped with segments crossing the Gökova Gulf from its northern part to south of Kos Island. This fault zone intersects and displaces the deep basins in the gulf. The basins are thus interpreted as the youngest deformed features in the study area. The strike-slip faults also produce E-W-oriented ridges between the basin segments, and the ridge-related vertical faults are interpreted as reverse faults. This offshore study reveals that the normal and strike-slip faults are well correlated with the focal mechanism solutions of the recent earthquake and general seismicity of the Gökova Gulf. Although the complex morphotectonic features could suggest that the area is under a transtensional regime, kinematic elements normally associated with a transtensional system are missing. At present, the Gökova Gulf is experiencing strike-slip motion with dominant extensional deformation, rather than transtensional deformation.

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

[Chemical characteristics of precipitation in South China Sea].

Science.gov (United States)

Xiao, Hong-Wei; Long, Ai-Min; Xie, Lu-Hua; Xiao, Hua-Yun; Liu, Cong-Qiang

2014-02-01

Rainwater samples were collected in the summer on "Shiyan 3" during the 2012 South China Sea Sectional Scientific Survey. The concentrations of anion and cation, and pH in precipitation were determined and backward trajectories of air mass were simulated to analyze the chemical characteristics of ions and examine the source of ions. The results indicated that the mean pH value of precipitation was 6.3, with 5.6 of minimal value in summer in South China Sea. The order of anion and cation abundance was Cl(-) > S04(2-) > NO3(-) and Na(+) > Mg(2+) > Ca(2+) > K(+). Cl(-) was the major anion and Na(+) was the major cation, with concentrations of 2 637.5 microeq x L(-1) and 2095.5 microeq x L(-1), respectively, showing that they were the characteristics of marine atmospheric precipitation. There was a good linear relationship between each pair of 7 ions, with correlation coefficient above 0.9, suggesting that they may have a common source. However, the correlation coefficients were lower between NO3(-) and other ions than the others, suggesting that NO3(-) had more complex sources. The concentrations of Ca(2+) and K(+) in precipitation may be related to coral environment in South China Sea. The backward trajectories in 6 stations showed that the air mass was from south and southwest of South China Sea, without passing through above the continent. These results suggested that precipitation affected by human ion source can be ignored in summer in South China Sea.

Sustainability assessment: dressing up SEA - experiences from South Africa

CSIR Research Space (South Africa)

Govender, K

2006-09-01

Full Text Available as Sustainability Assessment and how Strategic Environmental Assessment (SEA) has been conceptualised and promoted in South Africa. This paper therefore investigates the following questions: Could the South African concept and application of SEA be what is required...

Taxonomic research on deep-sea macrofauna in the South China Sea using the Chinese deep-sea submersible Jiaolong.

Science.gov (United States)

Li, Xinzheng

2017-07-01

This paper reviews the taxonomic and biodiversity studies of deep-sea invertebrates in the South China Sea based on the samples collected by the Chinese manned deep-sea submersible Jiaolong. To date, 6 new species have been described, including the sponges Lophophysema eversa, Saccocalyx microhexactin and Semperella jiaolongae as well as the crustaceans Uroptychus jiaolongae, Uroptychus spinulosus and Globospongicola jiaolongi; some newly recorded species from the South China Sea have also been reported. The Bathymodiolus platifrons-Shinkaia crosnieri deep-sea cold seep community has been reported by Li (2015), as has the mitochondrial genome of the glass sponge L. eversa by Zhang et al. (2016). The population structures of two dominant species, the shrimp Shinkaia crosnieri and the mussel Bathymodiolus platifrons, from the cold seep Bathymodiolus platifrons-Shinkaia crosnieri community in the South China Sea and the hydrothermal vents in the Okinawa Trough, were compared using molecular analysis. The systematic position of the shrimp genus Globospongicola was discussed based on 16S rRNA gene sequences. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Potential of sea level rise impact on South China Sea: a preliminary ...

African Journals Online (AJOL)

The effect of the sea level rise was involved the existence of sea water intrusion and coastal erosion phenomenon in the coastal of Terengganu. This study aim to determine fluctuation of high and low tides of the South China Sea in their relation to water quality value of Marang and Paka Rivers as well as from wells ...

The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea

Science.gov (United States)

Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai

2013-11-01

A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.

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.

Indonesia in the South China Sea Dispute: Humble-Hard Power

OpenAIRE

Robertua, Verdinand; Sinaga, Obsatar

2018-01-01

This research discussed the opportunities for Indonesia to act as humble-hard power in South China Sea dispute. Permanent Court of Arbitration’s decision in July 2016 to give South China Sea based on UNCLOS’s regulation has provoked China’s objection. This research question is on how to understand the conception of humble-hard power and the possibility for Indonesia to be humble-hard power in the South China Sea dispute? This article borrowed the concept of humble-hard power from Adam Nieves ...

Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

Science.gov (United States)

Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

2013-11-01

We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

Mesozoic Compressional Folds of the Nansha Waters, Southern South China Sea

Science.gov (United States)

Zhu, R.; Liu, H.; Yao, Y.; Wang, Y.

2017-12-01

As an important part of the South China Sea, the southern margin of the South China Sea is fundamental to understand the interaction of the Eurasian, Pacific and Indian-Australian plates and the evolution of the South China Sea. Some multi-channel seismic profiles of the Nansha waters together with published drillings and dredge data were correlated for interpretation. The strata of the study region can be divided into the upper, middle and lower structural layers. The upper and middle structural layers with extensional tectonics are Cenozoic; the lower structural layer suffered compression is Mesozoic. Further structural restoration was done to remove the Cenozoic tectonic influence and to calculate the Mesozoic tectonic compression ratios. The results indicate that two diametrically opposite orientations of compressive stress, S(S)E towards N(N)W orientation and N(N)W towards S(S)E orientation respectively, once existed in the lower structural layer of the study area and shared the same variation trend. The compression ratio values gradually decrease both from the north to the south and from the west to the east in each stress orientation. The phenomena may be related to the opening of the proto-South China Sea (then located in south of the Nansha block) and the rate of the Nansha block drifted northward in Late Jurassic to Late Cretaceous, which had pushed the Nansha block drifted northward until it collided and sutured with the Southern China Margin. Thus the opening of the present-day South China Sea may be related to this suture zone, which was tectonically weakness zone.Key words: Mesozoic compression; structural restoration; proto-South China Sea; Nansha waters; Southern South China Sea; Acknowledgements: The work was granted by the National Natural Science Foundation of China (Grant Nos. 41476039, 91328205, 41576068 and 41606080).

Potential risk assessment of metals in edible fish species for human consumption from the Eastern Aegean Sea.

Science.gov (United States)

Pazi, Idil; Gonul, L Tolga; Kucuksezgin, Filiz; Avaz, Gulsen; Tolun, Leyla; Unluoglu, Aydın; Karaaslan, Yakup; Gucver, S Mine; Koc Orhon, Aybala; Siltu, Esra; Olmez, Gulnur

2017-07-15

The levels of Hg, Cd, Pb, Cr, Cu and Zn were measured in the tissues of four edible fish species namely: Diplodus annularis, Pagellus erythrinus, Merluccius merluccius and Mullus barbatus, collected from the Turkish Coast of the Aegean Sea. Except for D. annularis, the levels of Cd and Pb in all fish tissues sampled in Aliaga Bay in 2009 were above the tolerable limits according to the Food and Agriculture Organization of the United Nations (FAO). Hg in P. erythrinus and M. barbatus were higher than the maximum permitted limits (FAO), while D. annularis and M. merluccius were lower than the limit for biota in the district of Aliaga. Although the Target Hazard Quotient (THQ) values for Cd, Pb, Cu, Cr, Zn in all fish samples were lower than 1.0, the THQ for Hg levels were higher than 1.0 for most of the samples. According to the THQ values, M. merluccius may be consumed in moderation from Aliaga Bay, while the consumption of M. barbatus and P. erythrinus collected from Aliaga Bay are potentially hazardous to human health due to the Hg concentrations. Fish collected from Izmir Bay can be consumed safely. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosynthetic potential of actinomycetes in brown forest soil on the eastern coast of the aegean sea

Science.gov (United States)

Shirokikh, I. G.; Shirokikh, A. A.

2017-11-01

The taxonomic and functional structures of the actinomycetal complex in the litter and upper horizon of the brown forest soil was studied in a Pinus brutia var. pendulifolia forest on the eastern coast of the Aegean Sea. The complex of actinomycetes included representatives of the Streptomyces and Micromonospora genera and oligosporus forms. Streptomycetes predominated (73.8%) in the soil, and micromonospores (66.7%) were dominants in the litter. Thirty isolates of ten Streptomyces species from five series and three sections prevailed. In the upper soil horizon, species of the Helvolo-Flavus Helvolus section predominated (48%); the S. felleus species occurred most frequently. Among the isolated cultures, the S. globisporus and S. sindenensis species capable to produce antitumor antibiotics were found. The testing of the antimicrobial activity of the natural isolates showed that five strains inhibit the growth of pathogenic Fusarium sp., Alternaria sp., Acremonium sp., and Bipolaris sorokiniana fungi. When testing the effect of streptomycetes on the production of cellulases, a high-efficient strain belonging to the S. noboritoensis species was revealed. All the streptomycetes isolated from the brown forest soil produced auxins at the rate of 7.8 to 19.7 μg of indole acetic acid/mL of the liquid medium in the presence of 200 mg/L of tryptophan. Twelve isolates of streptomycetes were transferred to the collection of biotechnologically promising cultures for studying their properties.

Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

Science.gov (United States)

Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

2017-12-01

This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

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

2004-06-01

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.

Backarc extension, detachments and granitoids in the Aegean, their relations to slab tear and asthenospheric flow

Science.gov (United States)

Jolivet, Laurent; Menant, Armel; Rabillard, Aurélien; Arbaret, Laurent; Augier, Romain; Gumiaux, Charles

2013-04-01

The Cycladic granitoids (Ikaria, Mykonos, Naxos, Kos, Lavrion, Serifos, Tinos) intruded the Aegean crust during a rather short period (17-10 Ma) compared to the much longer Oligo-Miocene crustal thinning phase (35 Ma to the Present). Their geochemical characteristics show that their sources have changed through time and space, with a progressive decreasing component of continental crust contamination with time and from east to west. They all interacted with large-scale detachments, namely the North Cycladic Detachment System (NCDS) in the north and the West Cycladic Detachment System (WCDS) in the south. In Mykonos, Naxos, Serifos and Ikaria the plutons are also associated with a high-temperature metamorphic dome of Miocene age. Their intrusion period roughly covers the same time window as the fast clockwise rotation of the western Aegean evidenced by paleomagnetic measurements and they are contemporaneous with a surge of alkaline volcanism in the eastern Aegean that can be related to a slab tear imaged below western Anatolia. The continental crust component in the Middle Miocene Cycladic plutons is not found in the early Miocene plutons of the northern Aegean, like in Kavala and Vrondou. They thus probably record a quite sudden thermal event in the Cyclades that led to the partial melting of the extending deep crust. We propose a model involving slab tear starting at ~17 Ma, fast retreat of the slab west of the tear and southwestward influx of hot asthenospheric material below the Aegean crust, leading to melting of the lower crust. Partial melting of the whole lower crust above the hot asthenospheric flow could explain the flat Moho observed below the Cyclades. The close proximity of plutons with the detachments suggests that their ascent toward the upper crust is favoured by the extreme extension at work there. The first granitoids in the region of the tear (Ikaria) are the richest in crustal component and this component decreases while the crust thins more and

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

Energy Technology Data Exchange (ETDEWEB)

Agostini, S; Tonarini, S [Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Via G. Moruzzi 1, 56124 Pisa (Italy); Doglioni, C [Dipartimento di Scienze della Terra, Universita La Sapienza, Roma (Italy); Innocenti, F [Dipartimento di Scienze della Terra, Universita di Pisa, Pisa (Italy); Manetti, P [Dipartimento di Scienze della Terra, Universita di Firenze, Firenze (Italy)], E-mail: s.agostini@igg.cnr.it

2008-07-01

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, {delta}{sup 11}B and {delta}{sup 7}Li, 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

Early Chinese Voyaging in the South China Sea: Implications on Territorial Claims

Directory of Open Access Journals (Sweden)

Michael Flecker

2017-07-01

Full Text Available The main purpose of this paper is to examine historically issues of territorial claims over the South China Sea. As it is known that at present there are at least six countries claiming part or all of South China Sea territory. In this case China is the most ambitious country to control all areas in the South China Sea. This has led to political and military tensions in the region. It is strange that the South China Sea waters has actually been a shipping thoroughfare for the last two millennia. Therefore, this historical study will contribute to an understanding of the issues that could provoke international conflict.

Absolute dating of the Aegean Late Bronze Age

International Nuclear Information System (INIS)

Warren, P.M.

1987-01-01

A recent argument for raising the absolute date of the beginning of the Aegean Late Bronze (LB) Age to about 1700 B.C. is critically examined. It is argued here that: (1) the alabaster lid from Knossos did have the stratigraphical context assigned to it by Evans, in all probability Middle Minoan IIIA, c. 1650 B.C.; (2) the attempt to date the alabastron found in an early Eighteenth Dynasty context at Aniba to Late Minoan IIIA:1 is open to objections; (3) radiocarbon dates from Aegean LB I contexts are too wide in their calibrated ranges and too inconsistent both within and between site sets to offer any reliable grounds at present for raising Aegean LB I absolute chronology to 1700 B.C. Other evidence, however, suggests this period began about 1600 B.C., i.e. some fifty years earlier than the conventional date of 1550 B.C. (author)

Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea

NARCIS (Netherlands)

Yokokawa, Taichi; De Corte, Daniele; Sintes, Eva; Herndl, Gerhard J.

2010-01-01

To determine the variation of bacterial activity and community composition between and within specific water masses, samples were collected throughout the water column at 5 stations in the eastern Mediterranean Sea corresponding to the regions of the northern Aegean, mid-Aegean, western Cretan,

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)...

China's South China Sea Conundrum - No Easier Pass

OpenAIRE

Jash, Amrita

2016-01-01

On July 12, 2016, The Hague- based Permanent Court of Arbitration (PCA) finally hit the hammer on the verdict of the landmark case of South China Sea arbitration. This case was unilaterally initiated by the Republic of the Philippines on January 22, 2013, on its relevant disputes in the South China Sea with the People’s Republic of China. At the very outset, this case brought China at crossroads to its international repute given Philippines’ allegations against its assertive and unlawful clai...

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

Directory of Open Access Journals (Sweden)

M. Vacchi

2012-04-01

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

137Cs inventories in the water column collected from the South and South China Seas

International Nuclear Information System (INIS)

Yamada, M.; Wang, Z.-L.; Zheng, J.

2006-01-01

Seawater samples were collected in the Sulu and South China Seas and their 137 Cs activities were determined by γ spectrometry. A significant difference in intermediate water 137 Cs activities in the 750-1500 m depth was observed between the Sulu and South China Seas. The 137 Cs inventories in the Sulu Sea was 5.7 times higher than that of the integrated deposition density of atmospheric global fallout at the same latitude of 0-10degN. A possible mechanism controlling this extremely high 137 Cs inventories may be inflows of 137 Cs rich North Pacific Tropical Water and upper North Pacific Intermediate Water through the Luzon Straight from the West Philippine Sea, and lateral transport across the Mindoro Strait into the Sulu Sea, then conveyance into the deep layer in the Sulu Sea basin. (author)

Modal recovery of sea-level variability in the South China Sea using merged altimeter data

Science.gov (United States)

Jiang, Haoyu; Chen, Ge

2015-09-01

Using 20 years (1993-2012) of merged data recorded by contemporary multi-altimeter missions, a variety of sea-level variability modes are recovered in the South China Sea employing three-dimensional harmonic extraction. In terms of the long-term variation, the South China Sea is estimated to have a rising sea-level linear trend of 5.39 mm/a over these 20 years. Among the modes extracted, the seven most statistically significant periodic or quasi-periodic modes are identified as principal modes. The geographical distributions of the magnitudes and phases of the modes are displayed. In terms of intraannual and annual regimes, two principal modes with strict semiannual and annual periods are found, with the annual variability having the largest amplitudes among the seven modes. For interannual and decadal regimes, five principal modes at approximately 18, 21, 23, 28, and 112 months are found with the most mode-active region being to the east of Vietnam. For the phase distributions, a series of amphidromes are observed as twins, termed "amphidrome twins", comprising rotating dipole systems. The stability of periodic modes is investigated employing joint spatiotemporal analysis of latitude/longitude sections. Results show that all periodic modes are robust, revealing the richness and complexity of sea-level modes in the South China Sea.

Antifouling potentials of eight deep-sea-derived fungi from the South China Sea.

Science.gov (United States)

Zhang, Xiao-Yong; Xu, Xin-Ya; Peng, Jiang; Ma, Chun-Feng; Nong, Xu-Hua; Bao, Jie; Zhang, Guang-Zhao; Qi, Shu-Hua

2014-04-01

Marine-derived microbial secondary metabolites are promising potential sources of nontoxic antifouling agents. The search for environmentally friendly and low-toxic antifouling components guided us to investigate the antifouling potentials of eight novel fungal isolates from deep-sea sediments of the South China Sea. Sixteen crude ethyl acetate extracts of the eight fungal isolates showed distinct antibacterial activity against three marine bacteria (Loktanella hongkongensis UST950701-009, Micrococcus luteus UST950701-006 and Pseudoalteromonas piscida UST010620-005), or significant antilarval activity against larval settlement of bryozoan Bugula neritina. Furthermore, the extract of Aspergillus westerdijkiae DFFSCS013 displayed strong antifouling activity in a field trial lasting 4 months. By further bioassay-guided isolation, five antifouling alkaloids including brevianamide F, circumdatin F and L, notoamide C, and 5-chlorosclerotiamide were isolated from the extract of A. westerdijkiae DFFSCS013. This is the first report about the antifouling potentials of metabolites of the deep-sea-derived fungi from the South China Sea, and the first stage towards the development of non- or low-toxic antifouling agents from deep-sea-derived fungi.

New Mediterranean Biodiversity Records (July 2015

Directory of Open Access Journals (Sweden)

K. TSIAMIS

2015-07-01

The new records of alien species include: the red algae Antithamnionella elegans and Palisada maris-rubri, found for the first time in Israel and Greece respectively; the green alga Codium parvulum reported from Turkey (Aegean Sea; the first record of the alien sea urchin Diadema setosum in Greece; the nudibranch Goniobranchus annulatus reported from South-Eastern Aegean Sea (Greece; the opisthobranch Melibe viridis found in Lebanon; the new records of the blue spotted cornetfish Fistularia commersonii in the Alicante coast (Eastern Spain; the alien fish Siganus luridus and Siganus rivulatus in Lipsi Island, Dodecanese (Greece; the first record of Stephanolepis diaspros from the Egadi Islands Marine Protected Area (western Sicily; a northward expansion of the alien pufferfish Torquigener flavimaculosus along the southeastern Aegean coasts of Turkey; and data on the occurrence of the Lessepsian immigrants Alepes djedaba, Lagocephalus sceleratus and Fistularia commersonii in Zakynthos Island (SE Ionian Sea, Greece.

Countering Chinas Economic Statecraft in the South China Sea

Science.gov (United States)

2018-04-09

Economic Statecraft in the South China Sea 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Bradford D...created and employed a vision and strategy to control it. China continually demonstrates its economic might in the region and conducts economic ...power to counter China’s rising influence in the South China Sea. The policy and strategy should incorporate establishing strong economic ties in

Sea Reclamation Status of Countries around the South China Sea from 1975 to 2010

Directory of Open Access Journals (Sweden)

Junjue Zhang

2017-05-01

Full Text Available As a way of turning sea into land for living space for humans, the actions of sea reclamation bring about significant benefits. Nevertheless, it is also an under-recognized threat to the environment and the marine ecosystem. Based on images in two periods, sea reclamation information of countries around the South China Sea was extracted from 1975 to 2010. The spatial state and driven forces of sea reclamation are then discussed. Results show that the overall strength of sea reclamation in the South China Sea was great. New reclaimed land added up to 3264 km2. Sea reclamation for fish farming was the main reclamation type and widely distributed in the whole area, especially on the coast from the Pearl River Delta to the Red River Delta, and the coast of Ca Mau Peninsula. Sea reclamation in China and Vietnam was rather significant, which occupies 80.6% of the total reclamation area. Singapore had the highest level of sea reclamation. New reclaimed land for fish farming holds a key role in China, Vietnam, and Indonesia, while new reclaimed land for construction and docks dominated in Malaysia, Singapore, and Brunei. Areas and use-type compositions of new reclaimed land in countries varied greatly due to the differences of economic factors, policy inclination, and landscapes in the respective countries.

Recent sea experience in South Africa and national principles: Learning from national scale SEAs for renewable energy and power corridors

CSIR Research Space (South Africa)

Lochner, Paul A

2016-05-01

Full Text Available to legislate the outcomes of these SEAs. This is almost ten years since an updated version of the South African SEA Guidelines was released in 2007, which included principles for SEA in South Africa. This paper outlines the planning context, need and objectives...

Future Scenarios of the South China Sea Maritime Disputes

OpenAIRE

Shee, Poon Kim

2014-01-01

The focus of this paper is to analyze three future scenarios in the maritime disputes in the South China Sea. These namely are No War Scenario, Impasse Scenario and Peace Scenario. Ultimately, the way forward towards a viable solution to resolving the South China Sea maritime disputes between China and other claimant states depends on the political wisdom, will and determination of the disputing states. Lofty nationalistic aspirations have to be tempered with a degree of flexibility and pragm...

The new Hamburg Ocean Bottom Tiltmeter: A First Deployment at Columbo Seamount (Aegean Sea, Greece)

Science.gov (United States)

Hensch, M.; Hort, M.; Dahm, T.; Winter, S.; Klawonn, M.

2009-04-01

Assessing the state of volcanic activity of seamounts is quite more complicated than for onshore volcanoes, due to the difficulty of deploying instruments. At land, various techniques are applied (seismic networks, deformation studies, gas measurements etc.). At sea, mainly seismological observations are used. However, especially onshore deformation studies using INSAR have proven to be valuable in determining recharge of magmatic systems. We therefore developed a free fall, self leveling Ocean Bottom Tiltmeter (OBT) to observe deformation on the seafloor, using a two component high resolution tilt sensor with a resolution of about 1nrad (0.15μ°) and a maximum signal of about 0.045rad (0.5°). It is mounted inside a 17" glass sphere on a levelling stage, which relevels the instrument between ± 5° down to an accuracy of 0.006°. During the measurement this leveling stage is standing on the bottom of the glass sphere. For releveling, the instrument is pulled up by thin nylon strings and then locked to a gimbal system in order to compensate for tilt >5°. This releveling procedure is done once every 48 hours. Data is recorded on an 18bit data logger at 50Hz sampling rate. Additionally to tilt and seismic signals (using a hydrophone), temperature, absolute pressure to measure uplift or subsidence, and orientation (electronic compass) are monitored. 4 OBT systems were deployed between June 2006 and March 2007 at Columbo seamount, a submarine volcano north-east of Santorini island, Aegean Sea, Greece, on a 3 km long profile perpendicular to the first principal stress axis of the regional stressfield. Three of the instruments operated the whole time, one shut down due to a short circuit. First data processing indicates that small regional earthquakes as well as major tectonic earthquakes are properly recorded by the system. We find small, but permanent short-period deformations associated with local earthquakes and also observe long-period deformation processes

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

Directory of Open Access Journals (Sweden)

M. SALOMIDI

2016-08-01

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

Mitigating the Security Risks in the South China Sea Island Disputes

Science.gov (United States)

2014-02-13

third of the global crude oil and more than half of global gas shipping passes through the South China Sea. 2 For the United States, $1.2 trillion...China Sea. China, Taiwan, Vietnam, Philippines, Malaysia , and Brunei contest the sovereignty of these islands. In recent years, China has become...Administration estimates that the South China Sea holds approximately 11 billion barrels of oil 2 and 190 trillion cubic feet of natural gas

China in the South China Sea Dispute: Between Status Quo and Revisionist

OpenAIRE

Triwibowo, Albert

2014-01-01

The paper is trying to look whether China is a status quo power or a revisionist power in theSouth China Sea dispute based on status quo indicator developed by Johnston and perspectives onconformity towards norms. Meanwhile, this paper argues that China is neither a status quo nor arevisionist in the South China Sea dispute to the extent of its compliance with the Declaration on theConduct of Parties (DoC) in the South China Sea. Using status quo indicators developed by Johnstonand also the p...

Planaxidae (Mollusca, Gastropoda) from the South China Sea

Science.gov (United States)

Chen, Zhiyun; Zhang, Junlong; Lian, Xiping; Tan, Yehui

2018-03-01

Planaxidae is a family of tropical and subtropical marine gastropods that are adapted to an intertidal, rocky environment. The present study deals with three species in the family Planaxidae from the South China Sea: Planaxis sulcatus (von Born, 1778), Angiola longispira (Smith, 1872), and Supplanaxis niger (Quoy and Gaimard, 1833), based on specimens deposited in the Marine Biodiversity Collections of the South China Sea, Chinese Academy of Sciences. The taxonomic status, main morphological characteristics of the shell and radula, distribution, and habitat of these three planaxid species are presented. We also briefly discuss their morphological differences and the biogeographic distribution.

Inter-annual sea level variability in the southern South China Sea

Digital Repository Service at National Institute of Oceanography (India)

Soumya, M.; Vethamony, P.; Tkalich, P.

(SCS) is one of the western marginal seas of the Pacific Ocean, surrounded by South China, Indo China Peninsula, Malaysian Peninsula, Philippines and Borneo Island. The SCS is a semi- enclosed basin connected to the western Pacific Ocean through Taiwan.... Sea level trend and variability in the Singapore Strait. Ocean Science, 9(2). Torrence, C. and Compo, G.P., 1998. A practical guide to wavelet analysis. Bulletin of the American Meteorological Society, 79(1): 61-78. Vargas‐Hernandez, J.M., Wijffels...

Earthquake Scenario-Based Tsunami Wave Heights in the Eastern Mediterranean and Connected Seas

Science.gov (United States)

Necmioglu, Ocal; Özel, Nurcan Meral

2015-12-01

We identified a set of tsunami scenario input parameters in a 0.5° × 0.5° uniformly gridded area in the Eastern Mediterranean, Aegean (both for shallow- and intermediate-depth earthquakes) and Black Seas (only shallow earthquakes) and calculated tsunami scenarios using the SWAN-Joint Research Centre (SWAN-JRC) code ( Mader 2004; Annunziato 2007) with 2-arcmin resolution bathymetry data for the range of 6.5—Mwmax with an Mw increment of 0.1 at each grid in order to realize a comprehensive analysis of tsunami wave heights from earthquakes originating in the region. We defined characteristic earthquake source parameters from a compiled set of sources such as existing moment tensor catalogues and various reference studies, together with the Mwmax assigned in the literature, where possible. Results from 2,415 scenarios show that in the Eastern Mediterranean and its connected seas (Aegean and Black Sea), shallow earthquakes with Mw ≥ 6.5 may result in coastal wave heights of 0.5 m, whereas the same wave height would be expected only from intermediate-depth earthquakes with Mw ≥ 7.0 . The distribution of maximum wave heights calculated indicate that tsunami wave heights up to 1 m could be expected in the northern Aegean, whereas in the Black Sea, Cyprus, Levantine coasts, northern Libya, eastern Sicily, southern Italy, and western Greece, up to 3-m wave height could be possible. Crete, the southern Aegean, and the area between northeast Libya and Alexandria (Egypt) is prone to maximum tsunami wave heights of >3 m. Considering that calculations are performed at a minimum bathymetry depth of 20 m, these wave heights may, according to Green's Law, be amplified by a factor of 2 at the coastline. The study can provide a basis for detailed tsunami hazard studies in the region.

Internal Waves, South China Sea

Science.gov (United States)

1983-01-01

Subsurface ocean currents, frequently referred to as internal waves, are frequently seen from space under the right lighting conditions when depth penetration can be achieved. These internal waves observed in the South China Sea off the SE coast of the island of Hainan (18.5N, 110.5E) visibly demonstrate turbidity in the ocean's depths at the confluence of conflicting currents.

Cumulative impacts from multiple human activities on seagrass meadows in eastern Mediterranean waters: the case of Saronikos Gulf (Aegean Sea, Greece).

Science.gov (United States)

Brodersen, Maren Myrto; Pantazi, Maria; Kokkali, Athina; Panayotidis, Panayotis; Gerakaris, Vasilis; Maina, Irida; Kavadas, Stefanos; Kaberi, Helen; Vassilopoulou, Vassiliki

2017-12-05

Ecosystem-based management (EBM) addresses the fundamental need to account for cumulative impacts of human activities with the aim of sustainably delivering ecosystem services. The Saronikos Gulf, a large embayment of the Aegean Sea, provides a wide range of ecosystem services that are impacted by multiple human activities, deriving from the metropolitan area of Athens (situated at the northeast part of the Gulf). The anthropogenic impacts affect the status of several marine ecosystem components, e.g., seagrass meadows. Cymodocea nodosa meadows are only present at the most confined western part of the Gulf, whereas Posidonia oceanica meadows are mainly distributed in the inner and outer part of the Gulf. The aim of this study is to assess the cumulative impacts from multiple human activities on the seagrass meadows in the Gulf. The main results indicated that most impacted meadows are P. oceanica in the inner part of the Gulf, adjacent to the most urbanized coastal areas, and near port infrastructures. Land-based pollution, as well as physical damage and loss seem to be the main pressures exerted on the meadows. Understanding cumulative impacts is crucial for informing policy decisions under an EBM approach.

Diversification in continental island archipelagos: new evidence on the roles of fragmentation, colonization and gene flow on the genetic divergence of Aegean Nigella (Ranunculaceae).

Science.gov (United States)

Jaros, Ursula; Tribsch, Andreas; Comes, Hans Peter

2018-02-12

Disentangling the relative roles of past fragmentation (vicariance), colonization (dispersal) and post-divergence gene flow in the genetic divergence of continental island organisms remains a formidable challenge. Amplified fragment length polymorphisms (AFLPs) were used to (1) gain further insights into the biogeographical processes underlying the Pleistocene diversification of the Aegean Nigella arvensis complex; (2) evaluate the role of potential key factors driving patterns of population genetic variability (mating system, geographical isolation and historical contingencies); and (3) test the robustness of conclusions previously drawn from chloroplast (cp) DNA. Genetic diversity was analysed for 235 AFLP markers from 48 populations (497 individuals) representing 11 taxa of the complex using population genetic methods and Bayesian assignment tests. Most designated taxa are identifiable as genetically distinct units. Both fragmentation and dispersal-driven diversification processes occurred at different geological time scales, from Early to Late Pleistocene, specifically (1) sea barrier-induced vicariant speciation in the Cyclades, the Western Cretan Strait and Ikaria; and (2) bi-regional colonizations of the 'Southern Aegean Island Arc' from the Western vs. Eastern Aegean mainland, followed by allopatric divergences in Crete vs. Rhodos and Karpathos/Kasos. Outcrossing island taxa experienced drift-related demographic processes that are magnified in the two insular selfing species. Population genetic differentiation on the mainland seems largely driven by dispersal limitation, while in the Central Aegean it may still be influenced by historical events (island fragmentation and sporadic long-distance colonization). The biogeographical history of Aegean Nigella is more complex than expected for a strictly allopatric vicariant model of divergence. Nonetheless, the major phylogeographical boundaries of this radiation are largely congruent with the geography and

The new Hamburg Ocean-Bottom-Tiltmeter (OBT): A first deployment at Columbo Seamount (Aegean Sea, Greece)

Science.gov (United States)

Huebscher, C.; Hensch, M.; Hort, M.; Dahm, T.; Klawonn, M.; Winter, S.

2008-12-01

Assessing the state of volcanic activity of seamounts is quite more complicated than for onshore volcanoes, due to the difficulty of deploying instruments. At land, various techniques are applied (seismic networks, deformation studies, gas measurements etc.). At sea, mainly seismological observations are used. However, especially onshore deformation studies using INSAR have proven to be valuable in determining recharge of magmatic systems. We therefore developed a free fall, self leveling Ocean Bottom Tiltmeter (OBT) to observe deformation on the seafloor, using a two component high resolution tilt sensor with a resolution of about 1nrad (0.15μ°) and a maximum signal of about 0.045rad (0.5°). It is mounted inside a 17~inch glass sphere on a levelling stage, which relevels the instrument between ± 5° down to an accuracy of 0.006°. During the measurement this leveling stage is standing on the bottom of the glass sphere. For releveling, the instrument is pulled up by thin nylon strings and then locked to a gimbal system in order to compensate for tilt. This releveling procedure is done once every 48 hours. Data is recorded on an 18bit data logger at 50Hz sampling rate. Additionally to tilt and seismic signals (using a hydrophone), temperature, absolute pressure to measure uplift or subsidence, and orientation (electronic compass) are monitored. 4 OBT systems were deployed between June 2006 - March 2007 at Columbo seamount, a submarine volcano north-east of Santorini island, Aegean Sea, Greece, on a 3 km long profile perpendicular to the first principal stress axis σ_1 of the regional stressfield. Three of the instruments operated the whole time, one shut down due to a short circuit. First data processing indicates that small regional earthquakes as well as major tectonic earthquakes are properly recorded by the system. We find small, but permanent short- period deformations associated with local earthquakes and also observe long-period deformation processes

Characterization of bacterial diversity associated with deep sea ferromanganese nodules from the South China Sea.

Science.gov (United States)

Zhang, De-Chao; Liu, Yan-Xia; Li, Xin-Zheng

2015-09-01

Deep sea ferromanganese (FeMn) nodules contain metallic mineral resources and have great economic potential. In this study, a combination of culture-dependent and culture-independent (16S rRNA genes clone library and pyrosequencing) methods was used to investigate the bacterial diversity in FeMn nodules from Jiaolong Seamount, the South China Sea. Eleven bacterial strains including some moderate thermophiles were isolated. The majority of strains belonged to the phylum Proteobacteria; one isolate belonged to the phylum Firmicutes. A total of 259 near full-length bacterial 16S rRNA gene sequences in a clone library and 67,079 valid reads obtained using pyrosequencing indicated that members of the Gammaproteobacteria dominated, with the most abundant bacterial genera being Pseudomonas and Alteromonas. Sequence analysis indicated the presence of many organisms whose closest relatives are known manganese oxidizers, iron reducers, hydrogen-oxidizing bacteria and methylotrophs. This is the first reported investigation of bacterial diversity associated with deep sea FeMn nodules from the South China Sea.

Anthropogenic eutrophication affects the body size of Cymodocea nodosa in the North Aegean Sea: A long-term, scale-based approach.

Science.gov (United States)

Vasileios, Papathanasiou; Sotiris, Orfanidis

2017-12-07

The variation of eleven Cymodocea nodosa metrics was studied along two anthropogenic gradients in the North Aegean Sea, in two separate periods (July 2004 and July 2013). The aim was to specify existing monitoring programs on different kind of human-induced or natural stress for a better decision-making support. Key water variables (N-NO 2 , N-NO 3 , N-NH 4 , P-PO 4 , Chl-a, attenuation coefficient-K, and suspended solids) along with the stress index MALUSI were also estimated in each sampling effort. All metrics (except one) showed significant differences (pPERMANOVA and PCA of common meadows and metrics within nine years showed significant but not consistent differences. While the most impacted studied site of Viamyl remained unchanged, a significant improvement of water quality was observed in the second most impacted meadow of Nea Karvali, which however was reduced to half of its previous area. On the one hand that was the result of combined management practices in nearby aquacultures and lower industrial activities due to the economic crisis. On the contrary, dredging and excess siltation from changes in land catchments and construction of permanent structures may decrease seagrass abundance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

DEFF Research Database (Denmark)

Hasager, Charlotte Bay; Astrup, Poul; Zhu, Rong

2016-01-01

We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave...

Estimation of potential distribution of gas hydrate in the northern South China Sea

Science.gov (United States)

Wang, Chunjuan; Du, Dewen; Zhu, Zhiwei; Liu, Yonggang; Yan, Shijuan; Yang, Gang

2010-05-01

Gas hydrate research has significant importance for securing world energy resources, and has the potential to produce considerable economic benefits. Previous studies have shown that the South China Sea is an area that harbors gas hydrates. However, there is a lack of systematic investigations and understanding on the distribution of gas hydrate throughout the region. In this paper, we applied mineral resource quantitative assessment techniques to forecast and estimate the potential distribution of gas hydrate resources in the northern South China Sea. However, current hydrate samples from the South China Sea are too few to produce models of occurrences. Thus, according to similarity and contrast principles of mineral outputs, we can use a similar hydrate-mining environment with sufficient gas hydrate data as a testing ground for modeling northern South China Sea gas hydrate conditions. We selected the Gulf of Mexico, which has extensively studied gas hydrates, to develop predictive models of gas hydrate distributions, and to test errors in the model. Then, we compared the existing northern South China Sea hydrate-mining data with the Gulf of Mexico characteristics, and collated the relevant data into the model. Subsequently, we applied the model to the northern South China Sea to obtain the potential gas hydrate distribution of the area, and to identify significant exploration targets. Finally, we evaluated the reliability of the predicted results. The south seabed area of Taiwan Bank is recommended as a priority exploration target. The Zhujiang Mouth, Southeast Hainan, and Southwest Taiwan Basins, including the South Bijia Basin, also are recommended as exploration target areas. In addition, the method in this paper can provide a useful predictive approach for gas hydrate resource assessment, which gives a scientific basis for construction and implementation of long-term planning for gas hydrate exploration and general exploitation of the seabed of China.

The South China Sea Thermohaline Structure and Circulation

National Research Council Canada - National Science Library

Chu, Peter C; Ma, Binbing; Chen, Yuchun

2002-01-01

...), consisting of 116,019 temperature and 9,617 salinity profiles, during 1968-1984 to investigate the temporal and spatial variabilities of South China Sea thermohaline structures and circulation...

Discordant Early Miocene palaeomagnetic directions at the vicinity of the North Aegean Trough: tectonic or palaeofield feature?

Science.gov (United States)

Kontopoulou, D.; Valet, J. P.; Zananiri, I.; Voidomatis, P.

2017-12-01

The North Aegean Trough (N.A.T) is a major tectonic feature of North Aegean Sea. This is a large NE-SW transcurrent lineament that is interpreted as the continuation of the North Anatolian Fault, with a prominent dextral strike-slip motion. IAn intense igneous activity has developed along the N.A.T to its north through the presence of abundant plutonism and volcanism from Early Oligocene to Pliocene. A considerable amount of palaeomagnetic data display a systematic pattern of clockwise rotations with angles varying between 20°-40° since the Early Oligocene. In order to document the impact of the N.A.T to regional rotations, early Miocene lava flows have been extensively sampled in the islands of Samothrace and Lemnos located to the north and south of N.A.T, respectively. Two sets of directions have been defined from the palaeomagnetic studies. The first one corresponds to the expected North-East declinations with positive inclinations or to reversed South-West declinations with negative inclinations that were previously interpreted as a dextral rotations of this area. The second set, exhibits discordant and apparently erratic directions despite quite acceptable demagnetization behaviour and magnetic characteristics. In order to constrain further these directions we performed new samplings. The new measurements which include Thellier absolute palaeointensity experiments reveal that the intermediate directions are associated with low field values for Samothrace with a transitional field recorded between 21 and 17 Ma. The presence of single magnetization component and the variability of the lavas do not favor the possibility of self-reversal mechanisms. The consistency of the directions within each flow but also between lava flows of comparable ages in the two islands and the presence of normal and reverse polarities point to records of transitional directions. In both islands, the intermediate virtual geomagnetic poles exhibit a preference for equatorial latitudes

Sponge Aquaculture Trials in the East-Mediterranean Sea: New Approaches to Earlier Ideas

NARCIS (Netherlands)

Osinga, R.; Sidri, M.; Cerig, E.; Gokalp, S.Z.; Gokalp, M.

2010-01-01

Aquaculture trials were conducted in the East Aegean Sea with Dysidea avara and Chondrosia reniformis to test the possibility of growing these sponges in the vicinity of sea-based fish farms. Culturing sponges in the vicinity of fish farms may have two benefits: the sponges may grow faster due to an

Energy audit data for a resort island in the South China Sea

Directory of Open Access Journals (Sweden)

M. Reyasudin Basir Khan

2016-03-01

Full Text Available The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article “Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea” [1]. Keywords: Tioman, South China Sea, Load profile, Renewable energy, Resort Island, Energy audit

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

Directory of Open Access Journals (Sweden)

M. CORSINI-FOKA

2010-11-01

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

Seismic investigation of an ocean-continent transition zone in the northern South China Sea

Science.gov (United States)

Zhu, J.; Qiu, X.; Xu, H.; Zhan, W.; Sun, Z.

2011-12-01

Rifted continental margins and basins are mainly formed by the lithospheric extension. Thined lithosphere of passive continental margins results in decompression melt of magma and created oceanic crust and thined ocean-continent transition (OCT) zone. Two refraction profiles used ocean bottom seismometers deployed in the broad continental shelf and three multi-channel seismic reflection lines in the northern South China Sea, acquired by the ship "Shiyan 2" of the South China Sea Institute of Oceanology, Chinese Academy of Sciences in 2010, are processed and interpreted in this study. Seismic reflection lines cut through the Dongsha rise, Zhu-1 and Zhu-2 depression within a Tertiary basin, Pear River Mouth basin (called as Zhujiangkou basin). These tectonic features are clear imaged in the seismic reflection records. Numerous normal faults, cutted through the basement and related to the stretch of the northern South China Sea margin, are imaged and interpreted. Reflection characteristics of the ocean-continent transition (OCT) zone are summaried and outlined. The COT zone is mainly divided into the northern syn-rift subsidence zone, central volcano or buried volcano uplift zone and tilt faulted block near the South Chia Sea basin. Compared to the previous seismic reflection data and refraction velocity models, the segmentation range of the OCT zone is outlined, from width of about 225 km in the northeastern South China Sea , of 160 km in the central to of 110 km in the north-central South China Sea. Based on the epicenter distribution of sporadic and large than 6 magnitude earthquakes, it suggests the OCT zone in the northern South China Sea at present is still an active seismic zone.

Climatic anomalies in Northern South China Sea during 1986-1987 El Nino

Energy Technology Data Exchange (ETDEWEB)

Chen Tegu (Academia Sinica, Beijing (China)); Zhou Qiang

1990-05-01

In this paper, the climatic anomalies in Northern South China Sea (NSCS) during 1986-1987 El Nino were analyzed according to meteorological and hydrographic observation data. The results showed that the most apparent anomalies were: (1) continuously weaker monsoon strength, (2) continuously much higher South China Sea High Pressure strength; (3) in 1987 only six typhoons occurred in NSCS (four less than normal), with the first typhoon occurring on 25 June, (about one month later than usual); (4) positive air temperature anomaly, negative annual precipitation and evaporation anomaly; (5) sea surface temperature and surface salinity anomaly was positive; (6) monthly mean sea level was 1 to 10cm lower than normal.

China's Crisis Bargaining in the South China Sea Dispute (2010-2013)

OpenAIRE

Ramadhani, Eryan

2014-01-01

As one of China’s most intricate territorial dispute, the South China Sea dispute has sufficiently consumed significant amount of Chinese leaders’ attention in Beijing. This paper reveals that China exerts signaling strategy in its crisis bargaining over the South China Sea dispute. This strategy contains reassurance as positive signal through offering negotiation and appearing self-restraint and of negative signal by means of escalatory acts and verbal threats. China’s crisis bargaining in t...

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.

Energy audit data for a resort island in the South China Sea.

Science.gov (United States)

Basir Khan, M Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

2016-03-01

The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article "Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea" [1].

Oceanographic survey for radioactivity analysis in the South Sea of Korea

International Nuclear Information System (INIS)

Jung, Kyu Kui; Jeong, Chang Soo; Choi, Yang Ho

2006-12-01

The objectives of this work are to collect and provide the samples for radioactivity analysis and the fundamental data for the understanding of distribution and function of radioactive materials through oceanographic investigation and analysis in the South Sea of Korea. To achieve the objectives, we conducted twice oceanographic surveys and analyzed the oceanographic characteristics in the South Sea of Korea. In addition, for the radioactivity analysis, water samples and various marine organism were collected and provided to KINS

Oceanographic survey for radioactivity analysis in the South Sea of Korea

International Nuclear Information System (INIS)

Choi, Yong Kyu; Lee, Sam Keum; Lee, Yong Hwa; Choi, Ok In; Oh, Hyun Ju; Seo, Young Il; Yang, Jun Hyuk; Jung, Ra Young

2005-12-01

The objectives of this work are to collect and provide the samples for radioactivity analysis and the fundamental data for the understanding of distribution and function of radioactive materials through oceanographic investigation and analysis in the South Sea of Korea. To achieve the objectives, we conducted twice oceanographic surveys and analyzed the oceanographic characteristics in the South Sea of Korea. In addition, for the radioactivity analysis, water samples and various marine organism were collected and provided to KINS

Mapping Economic Development: The South Seas Government and Sugar Production in Japan’s South Pacific Mandate, 1919–1941

Directory of Open Access Journals (Sweden)

Ti Ngo

2012-03-01

Full Text Available Japan acquired the Mariana, Caroline, and Marshall Island chains as a League of Nations mandate following World War I. Why did the local administration (the South Seas Government or Nanyōchō heavily subsidize the establishment of a sugar industry? While the South Seas Government did not explicitly state why it chose to support the sugar industry despite the wealth of oceanic resources surrounding the islands, imperial maps of the South Pacific produced by the Japanese navy and the South Seas Government provide a window into how both parties envisioned and planned for the economic future of the mandate. These maps included information regarding the available natural resources, land, and culture level of the Micronesian population. The author argues that in depicting the islands as spaces where a “primitive” nonagricultural population failed to take advantage of the islands’ resources, mapmakers and officials planned for the mass migration of Japanese labor to the mandate in order to support a newly established sugar industry.

Exploring coral microbiome assemblages in the South China Sea.

Science.gov (United States)

Cai, Lin; Tian, Ren-Mao; Zhou, Guowei; Tong, Haoya; Wong, Yue Him; Zhang, Weipeng; Chui, Apple Pui Yi; Xie, James Y; Qiu, Jian-Wen; Ang, Put O; Liu, Sheng; Huang, Hui; Qian, Pei-Yuan

2018-02-05

Coral reefs are significant ecosystems. The ecological success of coral reefs relies on not only coral-algal symbiosis but also coral-microbial partnership. However, microbiome assemblages in the South China Sea corals remain largely unexplored. Here, we compared the microbiome assemblages of reef-building corals Galaxea (G. fascicularis) and Montipora (M. venosa, M. peltiformis, M. monasteriata) collected from five different locations in the South China Sea using massively-parallel sequencing of 16S rRNA gene and multivariate analysis. The results indicated that microbiome assemblages for each coral species were unique regardless of location and were different from the corresponding seawater. Host type appeared to drive the coral microbiome assemblages rather than location and seawater. Network analysis was employed to explore coral microbiome co-occurrence patterns, which revealed 61 and 80 co-occurring microbial species assembling the Galaxea and Montipora microbiomes, respectively. Most of these co-occurring microbial species were commonly found in corals and were inferred to play potential roles in host nutrient metabolism; carbon, nitrogen, sulfur cycles; host detoxification; and climate change. These findings suggest that the co-occurring microbial species explored might be essential to maintain the critical coral-microbial partnership. The present study provides new insights into coral microbiome assemblages in the South China Sea.

Chinese Assertiveness in the South China Sea and Southeast Asian Responses

Directory of Open Access Journals (Sweden)

Carlyle A. Thayer

2011-01-01

Full Text Available This article reviews Chinese assertive behaviour towards the Philippines and Vietnam over South China Sea issues in 2011. The article compares and contrasts Chinese diplomatic behaviour in the period before and after the adoption by ASEAN member states and China of Guidelines for the Implementation the Declaration on Conduct of Parties in the South China Sea in July. In the first period China aggressively asserted its claims to sovereignty by interfering with commercial fishing and oil exploration activities of vessels operating in the Exclusive Economic Zones of Vietnam and the Philippines. Both states resisted Chinese actions. The Philippines allocated increased funding for defence modernization, lobbied ASEAN states and shored up its alliance with the United States. Vietnam too protested Chinese action and undertook symbolic steps to defend national sovereignty. In the second period all states moved to contain South China Sea tensions from affecting their larger bilateral relations. It remains to be seen, however, if proposed confidence building measures will ameliorate Chinese assertiveness.

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

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Carlo Nike Bianchi

2011-06-01

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

Preventing Escalation in the South China Sea Disputed Waters: A Comparative Study of Republic of the Philippines and Socialist Republic of Vietnam

Science.gov (United States)

2015-03-01

Problem of Maritime Cooperation in the South China Sea,” in Security and International Politics in the South China Sea, eds. Sam Bateman and Ralf Emmers...South China Sea,” in Security and International Politics in the South China Sea: Towards a cooperative management regime, eds. Sam Bateman and Ralf...Cooperation in the South China Sea.” In Security and International Politics in the South China Sea, edited by Sam Bateman and Ralf Emmers. Oxon, UK

Opening of the South China Sea and Upwelling of the Hainan Plume

Science.gov (United States)

Yu, Mengming; Yan, Yi; Huang, Chi-Yue; Zhang, Xinchang; Tian, Zhixian; Chen, Wen-Huang; Santosh, M.

2018-03-01

Opening of the South China Sea and upwelling of the Hainan Plume are among the most challenging issues related to the tectonic evolution of East Asia. However, when and how the Hainan Plume affected the opening of the South China Sea remains unclear. Here we investigate the geochemical and isotopic features of the 25 Ma mid-ocean ridge basalt (MORB) in the Kenting Mélange, southern Taiwan, 16 Ma MORB drilled by the IODP Expedition 349, and 9 Ma ocean island basalt-type dredged seamount basalt. The 25 Ma MORBs reveal a less metasomatic depleted MORB mantle-like source. In contrast, the Miocene samples record progressive mantle enrichment and possibly signal the contribution of the Hainan Plume. We speculate that MORBs of the South China Sea which could have recorded plume-ridge source mixing perhaps appear since 23.8 Ma. On the contrary, the Paleocene-Eocene ocean island basalt-type intraplate volcanism of the South China continental margin is correlated to decompression melting of a passively upwelling fertile asthenosphere due to continental rifting.

South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004

National Research Council Canada - National Science Library

Chu, Peter C; Cheng, Kuo-Feng

2008-01-01

Ocean wave characteristics in the western Atlantic Ocean (Hurricane Region) to tropical cyclones have been investigated extensively, but not the regional seas in the western Pacific such as the South China Sea (Typhoon Region...

Post-rift magmatism in the Pearl River Mouth Basin, northern South China Sea

Science.gov (United States)

Xu, H.; Zhao, F.; Xia, S.; Sun, J.; Fan, C.

2017-12-01

Multi-beam, 2D seismic reflection and borehole data reveal that post-rift magmatism are widespread in the northern margin of South China Sea. A large-scale volcanic complex was identified at water depths of 500 to 3000 m, covering an area of ca. 8000 km2. This volcanic complex includes seamounts, igneous sills, dykes and intruded volcanic bodies. Combining data from exploration wells BY7-1 and BY2 with published seismic stratigraphic data, we can highlight multiple extrusive events from the Early Oligocene to Early Miocene, reflecting progressive continental breakup in the South China Sea. Most intruded magma through the continental crust also uplifted sediments up to the T6 unconformity. Given the evidence in this work that Early Miocene magmatic bodies were developed above or along faults, we suggest that post-rift magmatism in the northern margin of the South China Sea was largely controlled by the faults. Reactivation events in the faults are suggested to have generated preferential vertical pathways for the ascent of magma within a context of progressive continental breakup and thinned continental crust, as the South China Sea was being formed.

Anthropozoonotic Endoparasites in Free-Ranging ?Urban? South American Sea Lions (Otaria flavescens)

OpenAIRE

Hermosilla, Carlos; Silva, Liliana M. R.; Navarro, Mauricio; Taubert, Anja

2016-01-01

The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) tech...

Data from renewable energy assessments for resort islands in the South China Sea

Directory of Open Access Journals (Sweden)

M. Reyasudin Basir Khan

2016-03-01

Full Text Available Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015 [1]. Keywords: South China Sea, Solar radiation,wind speed, rainfall, microhydropower, PV system, Wind energy generation system

Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

International Nuclear Information System (INIS)

Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

2006-01-01

Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

Data from renewable energy assessments for resort islands in the South China Sea.

Science.gov (United States)

Basir Khan, M Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

2016-03-01

Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article "Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea" published in Energy (Khan et al., 2015) [1].

Aseismic blocks and destructive earthquakes in the Aegean

Science.gov (United States)

Stiros, Stathis

2017-04-01

Aseismic areas are not identified only in vast, geologically stable regions, but also within regions of active, intense, distributed deformation such as the Aegean. In the latter, "aseismic blocks" about 200m wide were recognized in the 1990's on the basis of the absence of instrumentally-derived earthquake foci, in contrast to surrounding areas. This pattern was supported by the available historical seismicity data, as well as by geologic evidence. Interestingly, GPS evidence indicates that such blocks are among the areas characterized by small deformation rates relatively to surrounding areas of higher deformation. Still, the largest and most destructive earthquake of the 1990's, the 1995 M6.6 earthquake occurred at the center of one of these "aseismic" zones at the northern part of Greece, found unprotected against seismic hazard. This case was indeed a repeat of the case of the tsunami-associated 1956 Amorgos Island M7.4 earthquake, the largest 20th century event in the Aegean back-arc region: the 1956 earthquake occurred at the center of a geologically distinct region (Cyclades Massif in Central Aegean), till then assumed aseismic. Interestingly, after 1956, the overall idea of aseismic regions remained valid, though a "promontory" of earthquake prone-areas intruding into the aseismic central Aegean was assumed. Exploitation of the archaeological excavation evidence and careful, combined analysis of historical and archaeological data and other palaeoseismic, mostly coastal data, indicated that destructive and major earthquakes have left their traces in previously assumed aseismic blocks. In the latter earthquakes typically occur with relatively low recurrence intervals, >200-300 years, much smaller than in adjacent active areas. Interestingly, areas assumed a-seismic in antiquity are among the most active in the last centuries, while areas hit by major earthquakes in the past are usually classified as areas of low seismic risk in official maps. Some reasons

New Fisheries-related data from the Mediterranean Sea (November, 2016

Directory of Open Access Journals (Sweden)

A. ANASTASOPOULOU

2016-11-01

Full Text Available In this fourth Collective Article, with fisheries-related data from the Mediterranean, we present weight-length relationships for eight deep-sea fish species (Brama brama, Conger conger, Etmopterus spinax, Molva macrophthalma, Mora moro, Pagellus bogaraveo, Phycis blennoides from the Eastern Ionian Sea; Scyliorhinus canicula from various locations in the Mediterranean Sea and weight-length relationships and condition factor of five Mugilidae species (Liza aurata, Liza saliens, Liza ramada, Mugil cephalus, Chelon labrosus from a Mediterranean lagoon in the Ionian Sea. Moreover, we present otolith weight, fish length and otolith length relationships of the red mullet (Mullus barbatus in the Aegean and Ionian Sea and otolith weight relationships in European hake (Merluccius merluccius from the Greek Seas.

Comparison of modern pollen distribution between the northern and southern parts of the South China Sea.

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Luo, Chuanxiu; Chen, Muhong; Xiang, Rong; Liu, Jianguo; Zhang, Lanlan; Lu, Jun

2015-04-01

The authors conducted a palynological analysis based on different number of air pollen samples for the northern and southern parts of the South China Sea, respectively, in order to give a reference to reconstruct the paleoclimate of the area. (1) Fifteen air pollen samples were collected from the northern part of the South China Sea from August to September 2011, and 13 air pollen samples were collected from the southern part of the South China Sea in December 2011. The pollen types were more abundant in the north than in the south. The total pollen number and concentration in the north was 10 times more than that in the south, which may be because of the sampling season. Airborne pollen types and concentrations have a close relationship with wind direction and distance from the sampling point to the continent. (2) Seventy-four samples were collected from surface sediments in the northern part of the South China Sea in the autumn. Thirty-three samples were collected from surface sediments in the southern part of the South China Sea in the winter. Pollen concentrations in the north were nearly 10 times higher than that in the south. This is because trilete spores are transported by rivers from Hainan Island to the sea and also by the summer monsoon-forced marine current. (3) Ten air pollen samples and 10 surface sediments samples were selected for comparison. The pollen and spores in the air were mainly herbaceous and woody pollen, excluding fern spores, having seasonal pollen characteristics. Pollen in the surface sediments were mainly trilete, Pinus, and herbaceous, and may also show a combination of annual pollen characteristics.

Social factors associated with pulmonary hydatid cyst in Aegean ...

African Journals Online (AJOL)

Social factors associated with pulmonary hydatid cyst in Aegean, Turkey. ... where there are insufficient environmental health and preventive medicine services. ... The offices of the public administration have a responsibility to inform citizens ...

Seismicity and stress state in the South China Sea, Indochina and their vicinity

Science.gov (United States)

Zang, Shaoxian; Wu, Zhongliang; Li, Aibing

1992-02-01

The distribution of earthquakes from 1973 to 1982 in the South China Sea, Indochina and their vicinity was studied using the data from I. S. C. It was found that the earthquakes are mainly concentrated along the boundaries of plates. Beside, some of shallow eartqhuakes are distributed in west part of Burma and the boundary between Burma and China, a few of earthquakes occurred in South China Sea. The features of Benioff zone along the boundaries between India plate, Philippine Sea plate and Eurasia plate were studied. The plate do not coupled well under the Java trench and the Philippine trench. The subducted India plate under Burmese range, Andaman—Nicobar arc moves NNE. The fault plane solutions of earthquakes were studied using the first motions of P wave. The stress state on subduction zones and within the area were deduced from the fault plane solutions and the fault movement. It was found that the direction of principal compression axis of stress is in the NNE in west part of Burma, in S—N in south and middle part of Bruma and Thailand, and in NNE or S—N in the South China Sea. It was also found that the stress state has close relation with the interaction of plates.

AoA Region: South Asian Seas

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A.

is an environmental assessment for the entire Bay of Bengal region (BOBP/ REP/67) prepared for the Swedish Centre for Coastal Development and Management of Aquatic Resources by Holmgren (1994) under the Bay of Bengal Programme. This assessment provides information...-based activities (UNEP 2001) includes information on the South Asian Seas region. Under the Environment Management-Capacity Building Project implemented by the Indian Ministry of Environment and Forests with funding support from the World Bank, the Integrated...

HOBIT-The new Hamburg Ocean Bottom Tiltmeter: A First Deployment at Columbo Seamount, Aegean Sea

Science.gov (United States)

Hort, M.; Hensch, M.; Winter, S.; Dahm, T.

2007-12-01

volcano north-east of Santorini island, Aegean Sea, Greece, on a 3 km long profile perpendicular to the first principal stress axis σ1 of the regional stressfield. Three of the instruments operated the whole time, one shut down due to a leak in the power supply leading to a short circuit. First data processing indicates that small regional earthquakes as well as major tectonic earthquakes are properly recorded by the system. Following some regional earthquakes occurring during a seismic swarm we find a small, but permanent deformation associated with the earthquakes. Later during the deployment we also observe slow deformation processes occurring over a period of days. The implications of these findings as well as the general operational principle of these instruments will be discussed in detail in the presentation.

Phlebotomine sand flies (Diptera: Psychodidae in the Greek Aegean Islands: ecological approaches

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Nikolaos Tsirigotakis

2018-02-01

Full Text Available Abstract Background Blood-sucking phlebotomine sand flies are the vectors of the protozoan parasites Leishmania spp. Different Phlebotomus species transmit different Leishmania species causing leishmaniases which are neglected diseases emerging/reemerging in new regions. Thirteen sand fly species, ten belonging to the medically important genus Phlebotomus and three belonging to Sergentomyia are known in Greece. An increasing number of human and dog cases are reported each year from all parts of the country including the Aegean Islands. However, no previous study has been conducted on the sand fly fauna on the islands, except for Rhodes and Samos. The aim of this study was to investigate sand fly species in eleven small Aegean islands; to understand species-specific relationships with environmental and climatic factors and to compare sand fly community parameters among islands. A risk analysis was carried out for each species using climatic and environmental variables. Results Nine sand fly species: Phlebotomus neglectus, P. tobbi, P. similis, P. simici, P. perfiliewi, P. alexandri, P. papatasi, Sergentomyia minuta and S. dentata, were collected from the islands studied. Phlebotomus (Adlerius sp. and Sergentomyia sp. specimens were also collected but not identified to the species level. There was a positive effect of distance from the sea on the abundance of P. neglectus, S. minuta and S. dentata, and a negative effect on the abundance of P. tobbi, P. simici and P. similis. In general, temperature preferences of sand fly populations were between 21 and 29 °C. Nevertheless, there were significant differences in terms of temperature and relative humidity preference ranges among species. The most important species found, P. neglectus, was indisputably the most adapted species in the study area with a very high reaction norm, favoring even the lower temperature and humidity ranges. Overall, the sand fly fauna in the islands was very rich but there

Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports.

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Daryabor, Farshid; Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

2016-01-01

A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.

Effect of Ocean Interannual Variability on Acoustic Propagation in the Philippine Sea and South China Sea

Science.gov (United States)

2017-06-01

depth in order to analyze the Deep Water (Figure 12). The maximum values are found in the Philippine Sea, eastern part of the Mindanao Island in May...the water column stability. The seasonal variability is modulated by interannual and decadal modes of variability. The same effects were found ...ABSTRACT (maximum 200 words ) Effect of interannual variability of temperature and salinity on acoustic propagation in the Philippine Sea and South

Precursory accelerated Benioff strain in the Aegean area

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Papazachos, C.; Papazachos, B. [Thessaloniki Univ., Thessaloniki (Greece). Geophysical Laboratory

2001-04-01

Accelerating seismic crustal information due to the occurrence of intermediate magnitude earthquakes leading to the generation of a main shock has recently been considered a critical phenomenon. This hypothesis is tested by the use of a large sample concerning the Aegean area. Elliptical critical regions for fifty-two strong main shocks, which have occurred in the Aegean area since 1930, have been identified by applying a power-law relation between the cumulative Benioff strain and the time to the main rupture. Empirical relations between the parameters of this model have been further improved by the use of a large data sample. The spatial distribution of pre shocks with respect to the main shock is examined and its tectonic significance is pointed out. The possibility of using the results of this work to predict the epicentre, magnitude and time of ensuing main shocks are discussed and further work towards this goal is suggested.

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

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Catlos, Elizabeth J.

2008-03-01

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

Boron isotopic compositions in growing corals from the South China Sea

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Xiao, Jun; Xiao, Yingkai; Jin, Zhangdong; Liu, Congqiang; He, Maoyong

2013-01-01

In order to determine incorporation of boron species, boron isotopic fractionation, and influence of trace elements on isotopic compositions of boron in corals (δ11Bcoral), concentrations of Mg, Sr, Na, B and δ11Bcoral in growing corals from the South China Sea were measured. Relative to seawater, Sr enriched while Mg depleted in corals in the South China Sea. Although the δ11Bcoral values were different from various species and were not closely correlated with the element concentrations in corals in the South China Sea, Mg(OH)2 existed in corals can result in high δ11Bcoral. Thus, it is necessary to examine the existence of Mg(OH)2 and to choose the same species when δ11Bcoral is used in the δ11B-pH proxy. Based on the measured δ11B values of corals and coexisting seawater as well as the seawater pH in the South China Sea, a new isotopic fractionation factor a4-3 between B(OH)4- and B(OH)3 was determined to be 0.979. Besides B(OH)4- into corals, our results showed that B(OH)3 may also be incorporated into corals with variable proportions. The incorporation of B(OH)3 into corals may challenge the hypothesis of δ11Bcoral = δ11B4, resulting in increasing uncertainty to the calculated seawater pH values to the δ11B-pH proxy. We suggested that a best-fit empirical equation between δ11B of bio-carbonates and seawater pH needs to be established by the precipitation experiments of inorganic carbonates or culture experiments of corals or foraminifera.

Distribution and Diversity of Microbial Eukaryotes in Bathypelagic Waters of the South China Sea.

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Xu, Dapeng; Jiao, Nianzhi; Ren, Rui; Warren, Alan

2017-05-01

Little is known about the biodiversity of microbial eukaryotes in the South China Sea, especially in waters at bathyal depths. Here, we employed SSU rDNA gene sequencing to reveal the diversity and community structure across depth and distance gradients in the South China Sea. Vertically, the highest alpha diversity was found at 75-m depth. The communities of microbial eukaryotes were clustered into shallow-, middle-, and deep-water groups according to the depth from which they were collected, indicating a depth-related diversity and distribution pattern. Rhizaria sequences dominated the microeukaryote community and occurred in all samples except those from less than 50-m deep, being most abundant near the sea floor where they contributed ca. 64-97% and 40-74% of the total sequences and OTUs recovered, respectively. A large portion of rhizarian OTUs has neither a nearest named neighbor nor a nearest neighbor in the GenBank database which indicated the presence of new phylotypes in the South China Sea. Given their overwhelming abundance and richness, further phylogenetic analysis of rhizarians were performed and three new genetic clusters were revealed containing sequences retrieved from the deep waters of the South China Sea. Our results shed light on the diversity and community structure of microbial eukaryotes in this not yet fully explored area. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Energy audit data for a resort island in the South China Sea

Science.gov (United States)

Basir Khan, M. Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

2015-01-01

The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article “Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea” [1]. PMID:26900590

Cretaceous–Eocene provenance connections between the Palawan Continental Terrane and the northern South China Sea margin

NARCIS (Netherlands)

Shao, Lei; Cao, Licheng; Qiao, Peijun; Zhang, Xiangtao; Li, Qianyu; van Hinsbergen, Douwe J.J.

2017-01-01

The plate kinematic history of the South China Sea opening is key to reconstructing how the Mesozoic configuration of Panthalassa and Tethyan subduction systems evolved into today's complex Southeast Asian tectonic collage. The South China Sea is currently flanked by the Palawan Continental Terrane

Early Neolithic settlement patterns and exchange networks in the Aegean

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Agathe Reingruber

2011-12-01

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

Philippines – China Relations: The Case of the South China Sea (Spratly Islands Claims

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Mark Anthony M. Velasco

2014-12-01

Full Text Available The research is focused on examining by describing historically the relationship between the Philippines and China in the disputed claims over the islands in South China Sea. To crystalize this goal, the discourse in the paper heavily employs inter-textual analysis that is logically arranged into an opening idea on the context of the conflicting issue over the islands situated in Spratlys, then followed by an extensive illustration of the relationship between the Philippines and China concerning the territorial claims over the islands of South China Sea. Subsequently, a brief reflection guided by the principle of territoriality is portrayed with the goal to authoritatively explain the idea of jurisdiction over the islands in the Spratly area. After that, the paper briefly concludes with a prospectus on the issue of South China Sea.

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)

Stability of submarine slopes in the northern South China Sea: a numerical approach

Science.gov (United States)

Zhang, Liang; Luan, Xiwu

2013-01-01

Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained ( Φ=0) cases. Results show that submarine slopes are stable when the slope is 13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.

Wind Profiles and Wave Spectra for Potential Wind Farms in South China Sea. Part II: Wave Spectrum Model

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Yichao Liu

2017-01-01

Full Text Available Along with the commercialization of offshore wind energy in China, the South China Sea has been identified as ideal for constructing offshore wind farms, especially for farms consisting of floating wind turbines over deep waters. Since the wind profiles and wave spectra are somewhat primitive for the design of an offshore wind turbine, engineering models describing the wind and wave characteristics in the South China Sea area are necessary for the offshore wind energy exploitation given the meteorological, hydrological, and geographical differences between the South China Sea and the North/Norwegian Sea, where the commonly used wind profile and wave spectrum models were designated. In the present study; a series of numerical simulations were conducted to reveal the wave characteristics in the South China Sea under both typhoon and non-typhoon conditions. By analyzing the simulation results; the applicability of the Joint North Sea Wave Project (JONSWAP spectrum model; in terms of characterizing the wind-induced wave fields in the South China Sea; was discussed. In detail; the key parameters of the JONSWAP spectrum model; such as the Phillips constant; spectral width parameter; peak-enhancement factor, and high frequency tail decay; were investigated in the context of finding suitable values.

A prototype statistical approach of oil pollution in the Mediterranean Sea

International Nuclear Information System (INIS)

Ventikos, N.P.; Psaraftis, H.N.

1998-01-01

In this paper, we present a detailed statistical survey of oil pollution in the greater area of the Mediterranean Sea (with a preference in the Greek Seas: eg. the Aegean Sea or the Ioanian Sea and the respective Greek fleet). The Mediterranean Sea exhibits a noticeable increase of oil pollution within the last 15 years as documented by data that is presented within this work. A new electronic data base tool with a multitude of operational capabilities that utilizes data from the REMPEC Organization in raw format is introduced. We further present a statistical analysis of the data which differentiates each incident according to the volume of spilled oil and we conclude with some interesting results and comments. (author)

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

Science.gov (United States)

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

2016-08-01

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

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

Science.gov (United States)

Friederich, W.; Brüstle, A.; Küperkoch, L.; Meier, T.; Lamara, S.; Egelados Working Group

2014-05-01

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 in volcanic areas, where both

A numerical study of the South China Sea Warm Current during winter monsoon relaxation

Science.gov (United States)

Zhang, Cong; Ding, Yang; Bao, Xianwen; Bi, Congcong; Li, Ruixiang; Zhang, Cunjie; Shen, Biao; Wan, Kai

2018-03-01

Using a Finite-Volume Community Ocean Model, we investigated the dynamic mechanism of the South China Sea Warm Current (SCSWC) in the northern South China Sea (NSCS) during winter monsoon relaxation. The model reproduces the mean surface circulation of the NSCS during winter, while model-simulated subtidal currents generally capture its current pattern. The model shows that the current over the continental shelf is generally southwestward, under a strong winter monsoon condition, but a northeastward counter-wind current usually develops between 50-and 100-m isobaths, when the monsoon relaxes. Model experiments, focusing on the wind relaxation process, show that sea level is elevated in the northwestern South China Sea (SCS), related to the persistent northeasterly monsoon. Following wind relaxation, a high sea level band builds up along the mid-shelf, and a northeastward current develops, having an obvious vertical barotropic structure. Momentum balance analysis indicates that an along-shelf pressure gradient provides the initial driving force for the SCSWC during the first few days following wind relaxation. The SCSWC subsequently reaches a steady quasi-geostrophic balance in the cross-shelf direction, mainly linked to sea level adjustment over the shelf. Lagrangian particle tracking experiments show that both the southwestward coastal current and slope current contribute to the northeastward movement of the SCSWC during winter monsoon relaxation.

The first Oligocene sea turtle (Pan-Cheloniidae record of South America

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Edwin Cadena

2018-03-01

Full Text Available The evolution and occurrence of fossil sea turtles at the Pacific margin of South America is poorly known and restricted to Neogene (Miocene/Pliocene findings from the Pisco Formation, Peru. Here we report and describe the first record of Oligocene (late Oligocene, ∼24 Ma Pan-Cheloniidae sea turtle remains of South America. The fossil material corresponds to a single, isolated and well-preserved costal bone found at the Montañita/Olón locality, Santa Elena Province, Ecuador. Comparisons with other Oligocene and extant representatives allow us to confirm that belongs to a sea turtle characterized by: lack of lateral ossification, allowing the dorsal exposure of the distal end of ribs; dorsal surface of bone sculptured, changing from dense vermiculation at the vertebral scute region to anastomosing pattern of grooves at the most lateral portion of the costal. This fossil finding shows the high potential that the Ecuadorian Oligocene outcrops have in order to explore the evolution and paleobiogeography distribution of sea turtles by the time that the Pacific and the Atlantic oceans were connected via the Panama basin.

Digenetic trematodes in South American sea lions from southern Brazilian waters.

Science.gov (United States)

Pereira, E M; Müller, G; Secchi, E; Pereira, J; Valente, A L S

2013-10-01

The aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in South American sea lions from the southern Brazilian coast. Twenty-four South American sea lions, Otaria flavescens (Carnivora: Otaridae), were found dead along the coast of Rio Grande do Sul State, Brazil, between June 2010 and September of 2011. Two trematode species were found in the intestines of O. flavescens, i.e., Stephanoprora uruguayense (Digenea: Echinostomatidae) and Ascocotyle (Phagicola) longa (Digenea: Heterophyidae). Ascocotyle (P.) longa reached a prevalence of 33.3% and mean intensity of 248,500, whereas S. uruguayense showed a prevalence of 4.2% and mean intensity of 202. The 2 trematode species infecting sea lions were likely transmitted by feeding on mullets, Mugil platanus, that commonly harbor heterophyid metacercariae. The present work is the first report of digenetic trematodes infecting O. flavescens in Brazil. The high prevalence and mean intensity values of the 2 trematode species infecting sea lions in the present study suggest caution in human consumption of mullets and other fish, which can be infected with the metacercariae of these trematodes known to have zoonotic potential.

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

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N. SIMBOURA

2008-05-01

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

A performance evaluation of strategic environmental assessment (SEA) processes within the South African context

International Nuclear Information System (INIS)

Retief, Francois

2007-01-01

SEA has been described as being more about process than about product. Yet very little research has been conducted to gain a better understanding of how SEA processes perform within developing country contexts. To address this gap in knowledge the research underlying this paper aimed to evaluate the quality of SEA processes within the South African context against specifically designed key performance indicators. Comparison of the different data patterns revealed general SEA process features as well as three broad models, namely the 'stand alone', 'central to decision making' and 'integrated' models. The research results suggest a particularly poor performance in terms of process quality for the SEA case studies investigated. Moreover, it shows that there is no one understanding of SEA process within the South African context. The main limitations related to a weak understanding of the decision making processes SEA aimed to inform, as well as an inability to incorporate flexibility into process design. To take the debate forward it is proposed that SEA follow-up and effectiveness research be explored to determine which of these models (if any) ultimately contributed to influencing decision making and promote sustainability

The South China Sea Dispute : Perspective of International Law

NARCIS (Netherlands)

Ma, Xuechan

2016-01-01

This article discusses the South China Sea dispute from the perspective of international law. First, it introduces some basic knowledge about international law in this field. In the second part, Spratly islands dispute is used as a concrete example to show how international law analyzes this kind of

Selectivity of commercial, larger mesh and square mesh trawl codends for deep water rose shrimp Parapenaeus longirostris (Lucas, 1846 in the Aegean Sea

Directory of Open Access Journals (Sweden)

Hakan Kaykaç

2009-09-01

Full Text Available We investigated the differences between size selectivity of a commercial codend (40 mm diamond mesh – 40D, a larger mesh codend (48 mm diamond mesh – 48D, and a square mesh codend (40 mm square mesh – 40S for Parapenaeus longirostris in international waters of the Aegean Sea. Selectivity data were collected by using a covered codend method and analysed taking between-haul variation into account. The results indicate significant increases in L50 values in relation to an increase in mesh size and when the square mesh is used in the commercial trawl codend. The results demonstrate that the commercially used codend (40D is not selective enough for P. longirostris in terms of length at first maturity. Changing from a 40D to a 48D codend significantly improves selection, with an increase of about 15% in the L50 values (carapace length 14.5 mm for 40D and 16.6 mm for 48D. Similarly, 40 mm square mesh, which has recently been legislated for EU Mediterranean waters, showed a 12.4% higher mean L50 value (16.3 mm than 40 mm diamond mesh for this species. However, despite these improvements, the 48D and 40S codends still need further improvements to obtain higher selectivity closer to the length at first maturity (20 mm carapace length.

Strategic and Operational Implications of Access to the South China Sea to Maintain Regional Peace and Security

National Research Council Canada - National Science Library

Nelson, Robert

2003-01-01

.... China currently claims all of the South China Sea and is in dispute with other Southeast Asian nation claimants. China's maritime claim Southeast Asia Nuclear Weapons Free Zone, and People's Liberation Army's Navy modernization are aimed at excluding the U.S. Navy for the South China Sea.

Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

Directory of Open Access Journals (Sweden)

Xuezhong Yu

2017-01-01

Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub

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

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W. Friederich

2014-05-01

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

Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

International Nuclear Information System (INIS)

Hafidz Yusoff; Zaini Assim; Samsur Mohamad

2012-01-01

Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C 31 / C 19 and C 29 / C 31 indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

South African legislation with respect to the control of pollution of the sea

CSIR Research Space (South Africa)

Rabie, MA

1981-01-01

Full Text Available This document is a compilation of South African legislation relating to the control of pollution of the sea within the jurisdiction of the Republic of South Africa. Legislation is considered as it deals with a) the source of pollution, b) the effect...

Sea level trends in South East Asian Seas (SEAS)

Science.gov (United States)

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

2014-10-01

Southeast Asian Seas (SEAS) span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian Oceans. The SEAS regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost two decades. Initial comparisons of global sea level reconstructions find that 17 year sea level trends over the past 60 years exhibit good agreement in areas and at times of strong signal to noise associated decadal variability forced by low frequency variations in Pacific trade winds. The SEAS region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer time scales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past twenty years, the rate of sea level rise is greatly reduced in the SEAS region. As a result of the influence of the PDO, the SEAS regional sea level trends during 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the SEAS will continue to be affected by GMSL rise occurring now and in the future.

O-pi e-de-i: on round building as an archetypical form of sacred space in the Aegean

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Evyenia Yiannouli

2011-12-01

Full Text Available The archaeological record supports the general proposition that the simplest form of architecture, the round building type, variously persisted throughout the Aegean prehistory. This paper makes a case for the identification of round building as a distinct genre of sacred space in the Aegean Bronze Age, Mycenaean Crete in particular, combining evidence from architecture, iconography and the scripts. Certain archetypical features are thus delineated. It is argued that the historical understanding of the emerging LBA state requires a study of the architecture prior to the 2nd millennium BC as much as other relevant evidence issuing from the latest Aegean strata.

Discrepancies in 14C dating as illustrated from the Egyptian new and middle kingdoms and from the Aegean bronze age and neolithic

International Nuclear Information System (INIS)

Hood, S.

1978-01-01

14 C dates available for the Middle and New Kingdoms in Egypt and for the Bronze Age and Neolithic in the Aegean are examined. The possibility is explored that calibrated dates vary from tree-ring dates by different margins in Egypt and the Aegean during the second millenium B.C. Apparent inconsistencies between 14 C dates from different Neolithic sites in the Aegean area are also noted. (author)

Sea-level trend in the South China Sea observed from 20 years of along-track satellite altimetric data

DEFF Research Database (Denmark)

Cheng, Yongcun; Xu, Qing; Andersen, Ole Baltazar

2014-01-01

The sea-level trend in the South China Sea (SCS) is investigated based on 20 years of along-track data from TOPEX and Jason-1/2 satellite altimetry. The average sea-level rise over all the regions in the study area is observed to have a rate of 5.1 ± 0.8 mm year-1 for the period from 1993 to 2012....... The steric sea level contributes 45% to the observed sea-level trend. These results are consistent with previous studies. In addition, the results demonstrate that the maximum sea-level rise rate of 8.4 mm year-1 is occurring off the east coast of Vietnam and eastern part of SCS. During 2010-2011, the La...... Niña event was highly correlated with the dramatic sea-level rise in the SCS; La Niña events were also associated with the maximum rate of sea rise off the east coast of Vietnam, which occurred during 1993 and 2012. We also evaluated the trends in the geophysical (e.g. dynamical atmospheric correction...

Study of southern CHAONAN sag lower continental slope basin deposition character in Northern South China Sea

Science.gov (United States)

Tang, Y.

2009-12-01

Northern South China Sea Margin locates in Eurasian plate,Indian-Australia plate,Pacific Plates.The South China Sea had underwent a complicated tectonic evolution in Cenozoic.During rifting,the continental shelf and slope forms a series of Cenozoic sedimentary basins,including Qiongdongnan basin,Pearl River Mouth basin,Taixinan basin.These basins fill in thick Cenozoic fluviolacustrine facies,transitional facies,marine facies,abyssal facies sediment,recording the evolution history of South China Sea Margin rifting and ocean basin extending.The studies of tectonics and deposition of depression in the Southern Chaonan Sag of lower continental slope in the Norther South China Sea were dealt with,based on the sequence stratigraphy and depositional facies interpretation of seismic profiles acquired by cruises of“China and Germany Joint Study on Marine Geosciences in the South China Sea”and“The formation,evolution and key issues of important resources in China marginal sea",and combining with ODP 1148 cole and LW33-1-1 well.The free-air gravity anomaly of the break up of the continental and ocean appears comparatively low negative anomaly traps which extended in EW,it is the reflection of passive margin gravitational effect.Bouguer gravity anomaly is comparatively low which is gradient zone extended NE-SW.Magnetic anomaly lies in Magnetic Quiet Zone at the Northern Continental Margin of the South China Sea.The Cenozoic sediments of lower continental slope in Southern Chaonan Sag can be divided into five stratum interface:SB5.5,SB10.5,SB16.5,SB23.8 and Hg,their ages are of Pliocene-Quaternary,late Miocene,middle Miocene,early Miocene,paleogene.The tectonic evolution of low continental slope depressions can be divided into rifting,rifting-depression transitional and depression stages,while their depositional environments change from river to shallow marine and abyssa1,which results in different topography in different stages.The topographic evolvement in the study

Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

Science.gov (United States)

Yi, Liang; Chen, Yanping

2013-04-01

marine surface and core samples, and to quantitatively reconstruct sea-level variation since the late Pleistocene in the south Bohai Sea, China. New insights into regional relative sea-level changes since the late Pleistocene are obtained (Yi et al., 2012): (1) The grain size of surface and core samples can be mathematically partitioned using the Weibull distribution into four components. These four components with differing modal sizes and percentages could be interpreted as a long-term suspension component, which only settles under low turbulence conditions, sortable silt and very fine sand components transported by suspension during greater turbulence and bedload transport component, respectively. (2) Through regression and rigorous verification techniques, the reference water level could be reconstructed from sediment grain size. The reconstruction quantitatively extends the regional relative sea-level history to the late Pleistocene, providing a comparatively long dataset to evaluate regional sea-level variability. (3) We find no evidence of a sea-level high stand during MIS3 but rather a substantial regression during 70-30 cal kyr BP and potentially exposed land during 38-20 cal kyr BP. These results for the south Bohai Sea are in good agreement with published global sea-level records for the late Pleistocene, implying similarities between local and global sea-level patterns. Therefore, it is concluded that grain-size based sea-level reconstruction provide results that are comparable to other reconstruction methods and demonstrates great potential application for future works. (The data was shared on http://hurricane.ncdc.noaa.gov/) References Chappell, J., Omura, A., Esat, T., McCulloch, M., Pandolfi, J., Ota, Y., Pillans, B., 1996. Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records. Earth and Planetary Science Letters 141, 227-236. Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes

Main Introduction Way of Indo-Pacific and Red Sea Originated Benthic Foraminifers to the Eastern Mediterranean

Directory of Open Access Journals (Sweden)

Engin MERİÇ

2015-12-01

Full Text Available Majority of the alien foraminifers recorded in the eastern Mediterranean are Indo-Pacific originated and entered the Mediterranean via Suez Canal. In this study, current literature on the alien benthic foraminiferal fauna of the eastern Mediterranean was reviewed and the main dispersal pathways are determined. Distribution patterns of the alien species suggests that most of the species are introduced via Suez Canal and expand their range of distributions in a counter-clockwise manner by the general surface currents of the eastern Mediterranean. However, not all, but some of the species have also been dispersed westwards along the North African coast and reached central Mediterranean. Locally abundant records of Euthymonacha polita (Chapman, Coscinospira acicularis (Batsch and Amphistegina lobifera in the Aegean Sea indicates that Suez Canal may not be the only vector for the Indo-Pacific species to enter eastern Mediterranean and submarine springs help these thermophilic species to form establish populations in cool waters of the northern Aegean and the Sea of Marmara

Numerical assessment of factors affecting nonlinear internal waves in the South China Sea

Science.gov (United States)

Li, Qiang

2014-02-01

Nonlinear internal waves in the South China Sea exhibit diverse characteristics, which are associated with the complex conditions in Luzon Strait, such as the double ridge topography, the Earth’s rotation, variations in stratification and the background current induced by the Kuroshio. These effects are individually assessed using the MITgcm. The performance of the model is first validated through comparison with field observations. Because of in-phased ray interaction, the western ridge in Luzon Strait intensifies the semidiurnal internal tides generated from the eastern ridge, thus reinforcing the formation of nonlinear internal waves. However, the ray interaction for K1 forcing becomes anti-phased so that the K1 internal tide generation is reduced by the western ridge. Not only does the rotational dispersion suppress internal tide generation, it also inhibits nonlinear steepening and consequent internal solitary wave formation. As a joint effect, the double ridges and the rotational dispersion result in a paradoxical phenomenon: diurnal barotropic tidal forcing is dominant in Luzon Strait, but semidiurnal internal tides prevail in the deep basin of the South China Sea. The seasonal variation of the Kuroshio is consistent with the seasonal appearance of nonlinear internal waves in the South China Sea. The model results show that the westward inflow due to the Kuroshio intrusion reduces the amplitude of internal tides in the South China Sea, causing the weakening or absence of internal solitary waves. Winter stratification cannot account for the significant reduction of nonlinear internal waves, because the amplitude growth of internal tides due to increased thermocline tilting counteracts the reduced nonlinearity caused by thermocline deepening.

Data from renewable energy assessments for resort islands in the South China Sea

Science.gov (United States)

Basir Khan, M. Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

2015-01-01

Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015) [1]. PMID:26779562

A geochemical and geochronological section through the Eastern Aegean

Science.gov (United States)

Boehm, Katharina; Kuiper, Klaudia; Vroon, Pieter; Wijbrans, Jan

2017-04-01

The convergence of Africa and Eurasia and the subduction of a oceanic lithosphere of narrow basins between Gondwana terranes has controlled the geological evolution of the Eastern Mediterranean region since the Cretaceous. This resulted in back-arc extension and lithospheric thinning caused by slab roll-back together with the westward extrusion of Anatolia, in the southwards retreat and stepwise development of the subduction system and also in a low velocity seismic anomaly gap between the Cyprus and Hellenic slab and other slab segments. However, the exact timing of all these events in the Eastern Mediterranean region is still a matter of debate, and the purpose of this study is therefore to disentangle when terrains collided and slab detached in the last 30Ma. In a N-S transect magmatic rocks of the Aegean plate are studied, including volcanics from the islands Nisyros, Kos, Patmos, Chios, Lesbos and Samothraki. Major- and trace elements as well as Sr-Nd-Hf-Pb-O isotopes are used to interpret the different features of the Aegean subduction zone. With this geochemical approach the extend of upwelling hot asthenospheric material from the slab tear can be traced in the recent to Eocene volcanic rocks. The volcanic rocks give a wide scatter in classification diagrams and pose for example the question how the sodium rich volcanic products of Patmos can be explained. On the other hand Chios seems to play a key role around 15 Ma years in a phase of relatively low volcanic activity. To get a reliable timeline of the subduction in the Aegean since the Eocene we are aiming to tie our chemical and isotopic data to parallel obtained geochronological ages. New 40Ar/39Ar data will allow us to get the needed resolution for this time span and material.

Cryptic genetic diversity in the mottled rabbitfish Siganus fuscescens with mitochondrial introgression at a contact zone in the South China Sea.

Science.gov (United States)

Ravago-Gotanco, Rachel; de la Cruz, Talna Lorena; Pante, Ma Josefa; Borsa, Philippe

2018-01-01

The taxonomy of the mottled rabbitfish Siganus fuscescens species complex has long been challenging. In this study, we analyzed microsatellite genotypes, mitochondrial lineages, and morphometric data from 373 S. fuscescens individuals sampled from the northern Philippines and Hong Kong (South China Sea, Philippine Sea and Sulu Sea basins), to examine putative species boundaries in samples comprising three co-occurring mitochondrial lineages previously reported to characterize S. fuscescens (Clade A and Clade B) or S. canaliculatus (Clade C). We report the existence of two cryptic species within S. fuscescens in the northeast region of the South China Sea and northern Philippine Sea, supported by genetic and morphological differences. Individual-based assignment methods recovered concordant groupings of individuals into two nuclear genotype clusters (Cluster 1, Cluster 2) with (1) limited gene flow, if any, between them (FST = 0.241; P South China Sea. Mitonuclear discordance due to introgression obscures phylogenetic relationships for recently-diverged lineages, and cautions against the use of mitochondrial markers alone for species identification within the mottled rabbitfish species complex in the South China Sea region.

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

Directory of Open Access Journals (Sweden)

K.G. PEHLIVANOGLOU

2004-06-01

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

The South China Sea Dispute: Perspective of International Law

OpenAIRE

Ma, Xuechan

2016-01-01

This article discusses the South China Sea dispute from the perspective of international law. First, it introduces some basic knowledge about international law in this field. In the second part, Spratly islands dispute is used as a concrete example to show how international law analyzes this kind of dispute. Finally, it analyzes the arbitration case between the Philippines and China.

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

Directory of Open Access Journals (Sweden)

Evangelos Pavlis

2017-05-01

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

A reanalysis dataset of the South China Sea

Science.gov (United States)

Zeng, Xuezhi; Peng, Shiqiu; Li, Zhijin; Qi, Yiquan; Chen, Rongyu

2014-01-01

Ocean reanalysis provides a temporally continuous and spatially gridded four-dimensional estimate of the ocean state for a better understanding of the ocean dynamics and its spatial/temporal variability. Here we present a 19-year (1992–2010) high-resolution ocean reanalysis dataset of the upper ocean in the South China Sea (SCS) produced from an ocean data assimilation system. A wide variety of observations, including in-situ temperature/salinity profiles, ship-measured and satellite-derived sea surface temperatures, and sea surface height anomalies from satellite altimetry, are assimilated into the outputs of an ocean general circulation model using a multi-scale incremental three-dimensional variational data assimilation scheme, yielding a daily high-resolution reanalysis dataset of the SCS. Comparisons between the reanalysis and independent observations support the reliability of the dataset. The presented dataset provides the research community of the SCS an important data source for studying the thermodynamic processes of the ocean circulation and meso-scale features in the SCS, including their spatial and temporal variability. PMID:25977803

Impacts of typhoon megi (2010) on the South China Sea

Science.gov (United States)

Ko, Dong Shan; Chao, Shenn-Yu; Wu, Chun-Chieh; Lin, I.-I.

2014-07-01

In October 2010, typhoon Megi induced a profound cold wake of size 800 km by 500 km with sea surface temperature cooling of 8°C in the South China Sea (SCS). More interestingly, the cold wake shifted from the often rightward bias to both sides of the typhoon track and moved to left in a few days. Using satellite data, in situ measurements and numerical modeling based on the East Asian Seas Nowcast/Forecast System (EASNFS), we performed detailed investigations. To obtain realistic typhoon-strength atmospheric forcing, the EASNFS applied typhoon-resolving Weather Research and Forecasting (WRF) model wind field blended with global weather forecast winds from the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS). In addition to the already known impacts from the slow typhoon translation speed and shallow pre-exiting ocean thermocline, we found the importance of the unique geographical setting of the SCS and the NE monsoon. As the event happened in late October, NE monsoon already started and contributed to the southwestward ambient surface current. Together with the topographicβ effect, the cold wake shifted westward to the left of Megi's track. It was also found that Megi expelled waters away from the SCS and manifested as a gush of internal Kelvin wave exporting waters through the Luzon Strait. The consequential sea level depression lasted and presented a favorable condition for cold dome development. Fission of the north-south elongated cold dome resulted afterward and produced two cold eddies that dissipated slowly thereafter.

Population genetics of Thamnaconus hypargyreus (Tetraodontiformes: Monacanthidae) in the South China Sea.

Science.gov (United States)

Li, Yufang; Chen, Guobao; Yu, Jie; Wu, Shuiqing; Xiong, Dan; Li, Xia; Cui, Ke; Li, Yongzhen

2016-01-01

Knowledge of population structure is particularly important for long-term fisheries management and conservation. Lesser-spotted leatherjacket Thamnaconus hypargyreus is an economically important fish species in the South China Sea. Fish specimens (totally 158 individuals) used in this study were collected from five geographical locations in the north of the South China Sea and the southwestern Nansha Islands. The results were as follows: a total of 636 nucleotides of the mitochondrial DNA (mtDNA) control region (CR) of T. hypargyreus were amplified by polymerase chain reaction (PCR) technology. Both 103 mutations of nucleotide acids without inserting or deleting one and 91 haplotypes were found among the examined CR fragment. High haplotype diversity (0.9419 ± 0.0151) and nucleotide diversity (0.0095 ± 0.00506) relatively together with a recent and sudden population expansion which characterizes the genetic population structure of this species. Analysis of molecular variance (AMOVA) and the fixation indices (Fst) of five groups showed that the genetic variance mainly came from individuals within groups, and there was no genetic differentiation between groups. The phylogenetic trees including maximum likelihood (ML) and Bayesian inference (BI) proved no phylogeographic differentiation structure in five groups. The mtDNA marker suggested the five groups should be genetic homogeneity, which implied T. hypargyreus in the north and southwest continental shelf of the South China Sea belongs to one population.

Transuranic elements in the marine environment: A study on the concentrations of Pu radioisotopes in Greek seas

International Nuclear Information System (INIS)

Danali-Cotsaki, S.; Florou-Gazi, H.

1982-09-01

The experimental methodology used for the determination of background levels of Pu in the Aegean Sea is described. Preliminary results have shown that Pu concentration levels in the examined areas are of the order of 1x10 -15 Ci/1(fCi/1). These results are compared to those from the North Adriatic Sea. Levels of mixed fission product concentrations in samples collected from the above areas are also reported and discussed. (T.A.)

Accurate relocation of seismicity along the North Aegean Trough and its relation to active tectonics

Science.gov (United States)

Konstantinou, K. I.

2017-10-01

The tectonics of northern Aegean are affected by the westward push of Anatolia and the gravitational spreading of the Aegean lithosphere that promote transtensional deformation in the area. This regime is also responsible for the creation of a series of pull-apart basins, collectively known as the North Aegean Trough. This work accurately relocates a total of 2300 earthquakes that were recorded along the North Aegean Trough during 2011-2016 by stations of the Hellenic Unified Seismic Network (HUSN) and strong-motion sensors. Absolute locations for these events were obtained using a nonlinear probabilistic algorithm and utilizing a minimum 1D velocity model with station corrections. The hypocentral depth distribution of these events shows a peak at 8 km diminishing gradually down to 20 km. A systematic overestimation of hypocentral depths is observed in the routine locations provided by the National Observatory of Athens where the majority of events appear to be deeper than 15 km. In order to obtain more accurate relative locations these events were relocated using the double-difference method. A total of 1693 events were finally relocated with horizontal and vertical uncertainties that do not exceed 0.11 km and 0.22 km respectively. Well-defined clusters of seismicity can be observed along the Saros and Sporades basins as well as the Kassandra and Sithonia peninsulas. These clusters either occur along the well-known NE-SW strike-slip faults bounding the basins, or along normal faults whose strike is perpendicular to the regional minimum stress axis. Locking depth along the North Aegean Trough is found to be remarkably stable between 13 and 17 km. This is likely a consequence of simultaneous reduction along the SW direction of heat flow (from 89 to 51 mW/m2) and strain rate (from 600 to 50 nstrain/yr) whose opposite effects are canceled out, precluding any sharp changes in locking depth.

The emperor's new clothes - Reflections on strategic environmental assessment (SEA) practice in South Africa

International Nuclear Information System (INIS)

Retief, Francois; Jones, Carys; Jay, Stephen

2008-01-01

This paper presents the results of research which evaluated the performance of strategic environmental assessment (SEA) practice in South Africa in order to develop understanding of how SEA functions within a developing country with a voluntary SEA system. The research applied a combination of methods in a mixed research strategy, including a macro level survey of the SEA system together with case study reviews exploring micro level application. Three main 'system features' emerged, namely expansion of voluntary practice, diversity in practice and general ineffectiveness. The results also highlight a number of 'application features' such as a lack of focus due to an inability to deal with the concepts of 'sustainability' and 'significance', as well as poor understanding and integration with decision-making processes. Moreover, it emerged that none of the case studies seem to have conducted an 'assessment' per se, but rather provided a framework for strategic decision-making. The paper puts forward a number of interrelated explanations for these system and application features. In a parallel to the fable of the 'emperor's new clothes', SEA in South Africa appears to be regarded as the answer to all environmental problems, whilst being ineffective in practice

Nannastacidae (Crustacea: Cumacea) from the Malayan shallow waters (South China Sea)

NARCIS (Netherlands)

Petrescu, Iorgu

1997-01-01

Four new species from the South China Sea are described: Nannastacus muelleri n.sp., Nannastacus wisseni n.sp., Scherocumella fagei n.sp. and Scherocumella malayensis n.sp. The descriptions of further 15 known species are complemented with new information ( Campylaspis amblyoda Gamo, 1960, Cumella

Relict thermokarst carbon source kept stable within gas hydrate stability zone of the South Kara Sea

Science.gov (United States)

Portnov, A.; Mienert, J.; Winsborrow, M.; Vadakkepuliyambatta, S.; Semenov, P.

2017-12-01

Substantial shallow sources of carbon can exist in the South Kara Sea shelf, extending offshore from the permafrost areas of Yamal Peninsula and the Polar Ural coast. Our study presents new evidence for >250 buried relict thermokarst units. These amalgamated thawing wedges formed in the uppermost permafrost of the past and are still recognizable in today's non-permafrost areas. Part of these potential carbon reservoirs are kept stable within the South Kara Sea gas hydrate stability zone (GHSZ). We utilize an extensive 2D high-resolution seismic dataset, collected in the South Kara Sea in 2005-2006 by Marine Arctic Geological Expedition (MAGE), to map distinctive U-shaped units that are acoustically transparent. These units appear all over the study area in water depths 50-250 m. Created by thermal erosion into Cretaceous-Paleogene bedrock, they are buried under the younger glacio-marine deposits and reach hundreds of meters wide and up to 100 meters thick. They show the characteristics of relict thermokarst, generated during ancient episode(s) of sea level regression of the South Kara Sea. These thermokarst units are generally limited by the Upper Regional Unconformity, which is an erosional horizon created by several glaciation events during the Pleistocene. On land, permafrost is known to sequester large volumes of carbon, half of which is concentrated within thermokarst structures. Based on modern thermokarst analogues we demonstrate with our study that a significant amount of organic carbon can be stored under the Kara Sea. To assess the stability of these shallow carbon reservoirs we carried out GHSZ modeling, constrained by geochemical analyses, temperature measurements and precise bathymetry. This revealed a significant potential for a GHSZ in water depths >225 m. The relict thermokast carbon storage system is stable under today's extremely low bottom water temperatures ( -1.7 °C) that allows for buried GHSZ, located tens of meters below the seabed

Past 140-year environmental record in the northern South China Sea: Evidence from coral skeletal trace metal variations

International Nuclear Information System (INIS)

Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A.; Frost, Ray L.

2014-01-01

About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986–1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. -- Highlights: • Geochemical behaviors of trace elements in corals from South China Sea were investigated. • Terrestrial input, SST, war and infrastructure explain about 77.4% of elements behaviors in coral. • Changes of trace elements in coral of Xisha Islands were mainly impacted by local activities. • Spatial change of elements in seawater by was evaluated in 1986–1997 using distribution coefficient K D of coral. -- 140-year changes in the trace metals in corals from South China Sea were investigated. The spatiotemporal change model of the metals in seawater was reconstructed using coral record

The south-eastern North Sea : losses of vertebrate fauna during the past 2000 years

NARCIS (Netherlands)

Wolff, W.J.

At least 31 species of marine mammals, marine and coastal birds, and marine and anadromous fish have disappeared temporarily or permanently from the coasts of The Netherlands and in most cases also from the south-eastern North Sea (south of 54 degrees N) during the past 2000 years-In 18-22 cases,

Modeling the barrier-layer formation in the South-Eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Durand, F.; Shankar, D.; DeBoyer Montegut, C.; Shenoi, S.S.C.; Blanke, B.; Madec, G.

and are partly from the SEAS, but are cooled east and south of Sri Lanka in the model. That the downwelled subsurface waters are warm and are not cooled leads to temperature inversions in the BL. The main forcing for this appears to be remotely-forced planetary...

Past and Present Resource Disputes in the South China Sea: The Case of Reed Bank

Directory of Open Access Journals (Sweden)

Micah S. Muscolino

2013-09-01

Full Text Available In 2012, tensions flared between China and the Philippines over plans to drill for oil in the Reed Bank, a disputed shoal in the South China Sea, rekindling fears about the possibility of military conflict over the area’s energy resources. This article shows that international controversy centering on the Reed Bank’s hydrocarbon reserves initially emerged during the oil crisis of the 1970s, when the pursuit of energy resources transformed the islets into a hotly contested area. As in recent years, oil exploration by multinational corporations in conjunction with the Philippines catalyzed international disputes. Vigorous protests from China and other nations that lay claim to territories in the South China Sea prompted the Philippines to assert its own jurisdictional claims. The territorial dispute pushed claimants to the brink of military confrontation in the 1970s, yet armed conflict failed to materialize. By examining the initial round of tensions surrounding oil exploration at Reed Bank, this article situates the current international competition for the South China Sea’s energy resources in historical perspective. Analyzing past disputes and their ultimate resolution offers insights into the dynamics of present tensions, while making it possible to critically engage with arguments predicting future “resource wars” in the South China Sea.

Discrimination of fine-grained sediment provenance using geochemical elements on the inner shelf of the Korean Strait (South Sea), Korea

Science.gov (United States)

Um, I. K.; Choi, M. S.

2017-12-01

The central South Sea mud (CSSM) is located between the Heuksan mud belt (HMB) in the Yellow Sea and Korea Strait shelf mud (KSSM) in the East Sea and developed along the eastward transport pathway in the South Sea. Major elements (Al, Fe, Mg, and Ti), trace elements (Li, Cs, Sc, and Rb), and rare earth elements (REEs) in the fine-grained sediments (HMB were deposited mostly in the W-CSSM, whereas those from the Seomjin River were deposited mostly in the E-CSSM

Molecular approach to the identification of fish in the South China Sea.

Directory of Open Access Journals (Sweden)

Junbin Zhang

Full Text Available BACKGROUND: DNA barcoding is one means of establishing a rapid, accurate, and cost-effective system for the identification of species. It involves the use of short, standard gene targets to create sequence profiles of known species against sequences of unknowns that can be matched and subsequently identified. The Fish Barcode of Life (FISH-BOL campaign has the primary goal of gathering DNA barcode records for all the world's fish species. As a contribution to FISH-BOL, we examined the degree to which DNA barcoding can discriminate marine fishes from the South China Sea. METHODOLOGY/PRINCIPAL FINDINGS: DNA barcodes of cytochrome oxidase subunit I (COI were characterized using 1336 specimens that belong to 242 species fishes from the South China Sea. All specimen provenance data (including digital specimen images and geospatial coordinates of collection localities and collateral sequence information were assembled using Barcode of Life Data System (BOLD; www.barcodinglife.org. Small intraspecific and large interspecific differences create distinct genetic boundaries among most species. In addition, the efficiency of two mitochondrial genes, 16S rRNA (16S and cytochrome b (cytb, and one nuclear ribosomal gene, 18S rRNA (18S, was also evaluated for a few select groups of species. CONCLUSIONS/SIGNIFICANCE: The present study provides evidence for the effectiveness of DNA barcoding as a tool for monitoring marine biodiversity. Open access data of fishes from the South China Sea can benefit relative applications in ecology and taxonomy.

Heavy metal contamination in the muscle of Aegean chub (Squalius fellowesii) and potential risk assessment.

Science.gov (United States)

Şaşi, Hüseyin; Yozukmaz, Aykut; Yabanli, Murat

2018-03-01

Especially after the industrial revolution, the amount of contaminants released in aquatic ecosystems has considerably increased. For this reason, the necessity to carry on research on the existence of contaminants, specifically heavy metals, has emerged. In this study, heavy metal concentrations in muscle tissues of Aegean chub, which was an endemic species of south western part of Turkey, gathered from Tersakan River were examined. Heavy metal concentrations of the samples were analyzed with ICP-MS. Estimated daily intakes (EDI), target hazard quotient (THQ), and carcinogenic risk (CR) of elements were calculated. The heavy metals detected in muscle tissues were Zn > Cu > Cr > Mn > Pb > Cd, consecutively. According to the results of the applied health risk assessment (EDI, THQ and CR) for heavy metal exposure from fish consumption in children and adults, it was determined that there was no any significant threat to human health.

New Mediterranean Marine biodiversity records (December, 2013

Directory of Open Access Journals (Sweden)

M. BILECENOGLU

2013-10-01

Full Text Available Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters; the nemertean Amphiporus allucens (Iberian Peninsula, Spain; the salp Salpa maxima (Syria; the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece; the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy; Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey; the reticulated leatherjack Stephanolepis diaspros and the halacarid Agaue chevreuxi (Sea of Marmara, Turkey; the slimy liagora Ganonema farinosum, the yellowstripe barracuda Sphyraena chrysotaenia, the rayed pearl oyster Pinctada imbricata radiata and the Persian conch Conomurex persicus (south-eastern Crete, Greece; the blenny Microlipophrys dalmatinus and the bastard grunt Pomadasys incisus (Ionian Sea, Italy; the brown shrimp Farfantepenaeus aztecus (north-eastern Levant, Turkey; the blue-crab Callinectes sapidus (Corfu, Ionian Sea, Greece. In addition, the findings of the following rare species improve currently available biogeographical knowledge: the oceanic pufferfish Lagocephalus lagocephalus (Malta; the yellow sea chub Kyphosus incisor (Almuñécar coast of Spain; the basking shark Cetorhinus maximus and the shortfin mako Isurus oxyrinchus (north-eastern Levant, Turkey.

Exergy analysis for a proposed binary geothermal power plant in Nisyros Island, Greece

DEFF Research Database (Denmark)

Koroneos, Christopher; Polyzakis, A.; Xydis, George

2017-01-01

and a measure of the quality of the different forms of energy in relation to given environmental conditions. In this paper, data from an experimental geothermal drill in the Greek Island of Nisyros, located in the south of the Aegean Sea, have been used in order to estimate the maximum available work...... resulted supporting technical feasibility of the proposed geothermal plant....

Geomorphological condition and sea bottom sediment characteristics of Sebagin coast for NPP site evaluation in South Bangka

International Nuclear Information System (INIS)

Yuliastuti; Heni Susiati; Yarianto Sugeng Budi Susilo

2015-01-01

Study on geomorphological condition and sea bottom sediment in the coastal area of Sebagin, South Bangka Regency, Bangka Belitung Province has been performed. Geomorphological of the seabed was valuable to identify geological structures that exist on the seabed layers. Whereas, sediments seabed characteristics was useful to provide portrait of seabed layer due to the stability of NPP site concerning the seismic aspect and the determination of water intake position. The objective of the study was to evaluate geomorphological condition and sea bed sediment characteristics in the South Bangka sea. Methodology used for evaluating geomorphological of the sea bed were Multi Beam Echo Sounder (MBES) and Single Beam Echo Sounder (SBES), while for sea bottom sediment characteristics, high resolution seismic reflection using SBP together with sediment sample analysis were used. The result of the study showed that the study area was a shallow water sea with a depth range of 1-59 m. Geomorphological profile of the sea bed tend to be irregular and based on the seismic interpretation, there were no fault exists. Result analysis on the sea bottom sediment showed that clay distribution dominated the study area. (author)

The relationship between the opening of South China Sea and the formation of the Tibetan Plateau (Invited)

Science.gov (United States)

Mo, X.

2010-12-01

The South China Sea is one of the largest marginal seas in western Pacific and underwent a complex history. Xu et al.(2004) suggested that the evolution of the South China Sea can be divided into two first order phases: Paleogene (—Early Miocene) rifting and Neogene post- rifting. An oceanic crust was formed during 32-17 Ma. Whether or not the opening of South China Sea were related to Indo-Eurasia collision and the formation of the Tibetan Plateau is one of challenging problem in Earth sciences. With an exception of the southwestern China, the Chinese continent has become an united continent in the Triassic by the Indosinian orogeny. However, the Qinghai-Tibet area in SW China was still an oceanic region, that is, the Neo-Tethys. During the period of 145-100 Ma, the Lhasa terrane collided with the Qiangtang terrane and added to the south margin of the Eurasian continent. On the other hand, the Indian plate subducted underneath the Eurasian continent since Jurassic- Cretaceous. Subsequently, collision between the two continents, India and Eurasia, were completed during 65-40 Ma, and went into a post-collisional stage, characterized by intra-continental movements, including intra-continental subduction, overthrust, strike-slip and so on. The Tibetan Plateau, the highest plateau in the world had been formed by multi-stage uplifts. Several huge strike-slip shear zone such as the Red River Fault and the Altyn were formed during that period. The >1000-km-long Oligocene—Miocene left-lateral Red River shear zone (RRSZ) and the Pliocene—active right-lateral Red River fault (RRF), stretching from SE Tibet to the South China Sea, has been cited as a lithospheric scale strike-slip fault. The age of RRSZ was recently determined no earlier than 31.9-24.2Ma and no later than 21.7 Ma (Searle et al., 2010). Many geologists believe that there possibly be close relationship between the opening of the South China Sea and Indo-Eurasia collision and the formation of the Tibetan

Distribution profiles of per- and poly fluoroalkyl substances (PFASs) and their re-regulation by ocean currents in the East and South China Sea.

Science.gov (United States)

Zheng, Hongyuan; Wang, Feng; Zhao, Zhen; Ma, Yuxin; Yang, Haizhen; Lu, Zhibo; Cai, Minggang; Cai, Minghong

2017-12-15

We investigated the distribution of 17 individual per- and polyfluoroalkyl substances (PFASs) in 42 surface water samples collected from the East and South China Seas (7.0-36.0°N, 110.0°N-123.0°E). Concentrations of 7 individual PFASs, including perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonamide (FOSA), were quantified in the East China Sea, but only concentrations of PFOA and FOSA were quantified in the South China Sea. The total concentrations of the 17 PFASs ranged from 181 to 2658pg/L in the East China Sea and from 62 to 494pg/L in the South China Sea. We also show that river fluxes and ocean currents had a strong influence on the distribution of PFASs in the East China Sea. Using ArcGIS 10.1, we show how ocean currents control the spatial distribution of PFOA in the central South China Sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

North Aegean core complexes, the gravity spreading of a thrust wedge

NARCIS (Netherlands)

Kydonakis, Konstantinos; Brun, Jean Pierre; Sokoutis, Dimitrios

2015-01-01

The North Aegean core complexes developed in middle Eocene soon after the end of continental block convergence and piling up of the Hellenic Thrust Wedge. They formed during back-arc extension, driven by the Hellenic slab rollback, at the back of the thrust wedge. A series of scaled laboratory

Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

Science.gov (United States)

Li, Jialin; Li, Nan; Li, Fuchao; Zou, Tao; Yu, Shuxian; Wang, Yinchu; Qin, Song; Wang, Guangyi

2014-01-01

The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS). Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones) and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

Directory of Open Access Journals (Sweden)

Jialin Li

Full Text Available The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS. Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

Disputes About Disputes: Understanding the South China Sea

Directory of Open Access Journals (Sweden)

Bill Hayton

2017-12-01

Full Text Available Steve Chan. China’s Troubled Waters: Maritime Disputes in Theoretical Perspectives. Cambridge: Cambridge University Press, 2016. Do Thanh Hai. Vietnam and the South China Sea: Politics, Security and Legality. New York: Routledge, 2017. The two books under review here demonstrate some of the diversity of writing within the discipline of international relations. In China’s Troubled Waters: Maritime Disputes in Theoretical Perspectives, political scientist Steve Chan, following Kant, describes his style as “nomothetic,” “which emphasizes attention to classes of events rather than specific episodes” (vii. Strategic and defense studies scholar Do Thanh Hai’s Vietnam and the South China Sea: Politics, Security and Legality is an example of what Chan calls the “idiographic approach,” focusing “on the more unique or specific aspects of the situation” (vii. Chan wants to be able to generalize and compare, and he explicitly eschews narratives of “who did what to whom.” Hai, on the other hand, is keen to make clear that it is China who did something to Vietnam. The most obvious criticism to make of his book is that it is written from an overtly Vietnamese perspective. That is a weakness, but also potentially a draw for those interested in the formulation of Vietnamese policy. Chan writes from an ostensibly neutral position, but, as we shall see, his analysis is rooted within a Chinese world view.

Environment and security in the South China Sea region : the role of experts, non-governmental actors and governments in regime building processes

OpenAIRE

Næss, Tom

1999-01-01

Background: The Spratly islands in the South China Sea are today the focal point of a territorial dispute that represents a serious threat to the regional security in Southeast Asia. Six governments - China, Vietnam, Taiwan, the Philippines, Malaysia and Brunei - have laid claims to all or some of the more than 230 islets, reefs and shoals in the Spratly area. The Peoples Republic of China (PRC) is a key player in the South China Sea conflict. However, the South China Sea is not jus...

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.

Methylmercury in fish from the South China Sea: Geographical distribution and biomagnification

International Nuclear Information System (INIS)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-01-01

Highlights: • A large-scale investigation of MeHg in 46 species of marine wild fish from South China Sea. • Log 10 MeHg concentration was significantly related to their length and wet weight. • Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. • Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic species. • Biomagnification of MeHg was site-specific. -- Abstract: We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ 15 N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log 10 MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log 10 (MeHg) and δ 15 N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea

Modeled connectivity of Acropora millepora populations from reefs of the Spratly Islands and the greater South China Sea

Science.gov (United States)

Dorman, Jeffrey G.; Castruccio, Frederic S.; Curchitser, Enrique N.; Kleypas, Joan A.; Powell, Thomas M.

2016-03-01

The Spratly Island archipelago is a remote network of coral reefs and islands in the South China Sea that is a likely source of coral larvae to the greater region, but about which little is known. Using a particle-tracking model driven by oceanographic data from the Coral Triangle region, we simulated both spring and fall spawning events of Acropora millepora, a common coral species, over a 46-yr period (1960-2005). Simulated population biology of A. millepora included the acquisition and loss of competency, settlement over appropriate benthic habitat, and mortality based on experimental data. The simulations aimed to provide insights into the connectivity of reefs within the Spratly Islands, the settlement of larvae on reefs of the greater South China Sea, and the potential dispersal range of reef organisms from the Spratly Islands. Results suggest that (1) the Spratly Islands may be a significant source of A. millepora larvae for the Palawan reefs (Philippines) and some of the most isolated reefs of the South China Sea; and (2) the relatively isolated western Spratly Islands have limited source reefs supplying them with larvae and fewer of their larvae successfully settling on other reefs. Examination of particle dispersal without biology (settlement and mortality) suggests that larval connectivity is possible throughout the South China Sea and into the Coral Triangle region. Strong differences in the spring versus fall larval connectivity and dispersal highlight the need for a greater understanding of spawning dynamics of the region. This study confirms that the Spratly Islands are likely an important source of larvae for the South China Sea and Coral Triangle region.

Mercury in the marine boundary layer and seawater of the South China Sea: Concentrations, sea/air flux, and implication for land outflow

Science.gov (United States)

Fu, Xuewu; Feng, Xinbin; Zhang, Gan; Xu, Weihai; Li, Xiangdong; Yao, Hen; Liang, Peng; Li, Jun; Sommar, Jonas; Yin, Runsheng; Liu, Na

2010-03-01

Using R/V Shiyan 3 as a sampling platform, measurements of gaseous elemental mercury (GEM), surface seawater total mercury (THg), methyl mercury (MeHg), and dissolved gaseous mercury (DGM) were carried out above and in the South China Sea (SCS). Measurements were collected for 2 weeks (10 to 28 August 2007) during an oceanographic expedition, which circumnavigated the northern SCS from Guangzhou (Canton), Hainan Inland, the Philippines, and back to Guangzhou. GEM concentrations over the northern SCS ranged from 1.04 to 6.75 ng m-3 (mean: 2.62 ng m-3, median: 2.24 ng m-3). The spatial distribution of GEM was characterized by elevated concentrations near the coastal sites adjacent to mainland China and lower concentrations at stations in the open sea. Trajectory analysis revealed that high concentrations of GEM were generally related to air masses from south China and the Indochina peninsula, while lower concentrations of GEM were related to air masses from the open sea area, reflecting great Hg emissions from south China and Indochina peninsula. The mean concentrations of THg, MeHg, and DGM in surface seawater were 1.2 ± 0.3 ng L-1, 0.12 ± 0.05 ng L-1, and 36.5 ± 14.9 pg L-1, respectively. In general, THg and MeHg levels in the northern SCS were higher compared to results reported from most other oceans/seas. Elevated THg levels in the study area were likely attributed to significant Hg delivery from surrounding areas of the SCS primarily via atmospheric deposition and riverine input, whereas other sources like in situ production by various biotic and abiotic processes may be important for MeHg. Average sea/air flux of Hg in the study area was estimated using a gas exchange method (4.5 ± 3.4 ng m-2 h-1). This value was comparable to those from other coastal areas and generally higher than those from open sea environments, which may be attributed to the reemission of Hg previously transported to this area.

Did opening of the South China Sea impact development of the Asian Monsoon? Results from Oligocene microfossils, IODP Site U1435, northern South China Sea

Science.gov (United States)

Kulhanek, Denise K.; Su, Xin; Li, Qianyu; Gregory, Mitch; Warny, Sophie; Clift, Peter D.

2016-04-01

Development of the Asian Monsoon is linked to uplift of the Himalayas and Tibetan Plateau in the Cenozoic, with good evidence for a strong monsoon system by the late Oligocene to early Miocene (e.g., Guo et al., 2002; Clift et al., 2008). However, Licht et al. (2014) suggested the presence of an Asian Monsoon in the late Eocene. Recent scientific ocean drilling in the Indian Ocean and surrounding marginal seas gives us the opportunity to test this hypothesis with newly recovered Paleogene sediment cores. International Ocean Discovery Program Expedition 349 to the South China Sea recovered a 30 m section of primarily lower Oligocene nannofossil-rich claystone at Site U1435, located near the northern continent/ocean boundary. A thick sandstone unit devoid of typical marine microfossils underlies the marine claystone. The sandstone is interpreted as a deltaic or restricted marine deposit and is dated to the Eocene based on the presence of organic-walled palynomorphs, suggesting that a hiatus of several million years likely separates the sandstone below from the Oligocene marine claystone. This hiatus is interpreted as the breakup unconformity, with paleodepths in the South China Sea increasing during the Oligocene. Thus, this claystone should record if opening of the South China Sea during the early Oligocene influenced development of the Asian Monsoon. Combined calcareous nannofossil and planktonic foraminifer biostratigraphy indicates that the 30 m section is primarily early Oligocene in age (~33.5-30 Ma) and was deposited on the middle slope, with paleodepths >500 m. Stable oxygen isotopes from planktonic foraminifers become heavier up-hole, suggestive of cooling/deepening in the region, whereas carbon isotopes record variable conditions with no distinct maxima or minima. Calcareous nannoplankton primarily live in the upper 50 m of the ocean and are sensitive to sea-surface temperature and nutrient conditions, thus making them useful recorders of paleoceanographic

Preliminary numerical simulation for shallow strata stability of coral reef in South China Sea

Science.gov (United States)

Tang, Qinqin; Zhan, Wenhuan; Zhang, Jinchang

2017-04-01

Coral reefs are the geologic material and special rock and soil, which live in shallow water of the tropic ocean and are formed through biological and geological action. Since infrastructure construction is being increasingly developed on coral reefs during recent years, it is necessary to evaluate the shallow strata stability of coral reefs in the South China Sea. The paper is to study the borehole profiles for shallow strata of coral reefs in the South China Sea, especially in the hydrodynamic marine environment?, and to establish a geological model for numerical simulation with Geo-Studio software. Five drilling holes show a six-layer shallow structure of South China Sea, including filling layer, mid-coarse sand, coral sand gravel, fine sand, limestone debris and reef limestone. The shallow coral reef profile next to lagoon is similar to "layers cake", in which the right side close to the sea is analogous to "block cake". The simulation results show that coral reef stability depends on wave loads and earthquake strength, as well as the physical properties of coral reefs themselves. The safety factor of the outer reef is greater than 10.0 in the static condition, indicating that outer reefs are less affected by the wave and earthquake. However, the safety factor next to lagoon is ranging from 0.1 to 4.9. The main reason for the variations that the strata of coral reefs close to the sea are thick. For example, the thickness of reef limestone is more than 10 m and equivalent to the block. When the thickness of inside strata is less than 10 m, they show weak engineering geological characteristics. These findings can provide useful information for coral reef constructions in future. This work was funded by National Basic Research Program of China (contract: 2013CB956104) and National Natural Science Foundation of China (contract: 41376063).

Dependence between sea surge, river flow and precipitation in south and west Britain

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C. Svensson

2004-01-01

Full Text Available Estuaries around Great Britain may be at heightened risk of flooding because of the simultaneous occurrence of extreme sea surge and river flow, both of which may be caused by mid-latitude cyclones. A measure especially suited for extremes was employed to estimate dependence between river flow and sea surge. To assist in the interpretation of why flow-surge dependence occurs in some areas and not in others, the dependence between precipitation and surge and between precipitation and river flow was also studied. Case studies of the meteorological situations leading to high surges and/or river flows were also carried out. The present study concerns catchments draining to the south and west coasts of Great Britain. Statistically significant dependence between river flow and daily maximum sea surge may be found at catchments spread along most of this coastline. However, higher dependence is generally found in catchments in hilly areas with a southerly to westerly aspect. Here, precipitation in south-westerly airflow, which is generally the quadrant of prevailing winds, will be enhanced orographically as the first higher ground is encountered. The sloping catchments may respond quickly to the abundant rainfall and the flow peak may arrive in the estuary on the same day as a large sea surge is produced by the winds and low atmospheric pressure associated with the cyclone. There are three regions where flow-surge dependence is strong: the western part of the English south coast, southern Wales and around the Solway Firth. To reduce the influence of tide-surge interaction on the dependence analysis, the dependence between river flow and daily maximum surge occurring at high tide was estimated. The general pattern of areas with higher dependence is similar to that using the daily maximum surge. The dependence between river flow and daily maximum sea surge is often strongest when surge and flow occur on the same day. The west coast from Wales and

Investigating plant–pollinator relationships in the Aegean: the approaches of the project POL-AEGIS (The pollinators of the Aegean archipelago: diversity and threats)

OpenAIRE

Petanidou, Theodora; Ståhls, Gunilla; Vujić, Ante; Olesen, Jens M.; Rojo Velasco, Santos; Thrasyvoulou, Andreas; Sgardelis, Stefanos; Kallimanis, Athanasios S.; Kokkini, Stella; Tscheulin, Thomas

2013-01-01

Worldwide, there is a well-documented crisis for bees and other pollinators which represent a fundamental biotic capital for wild life conservation, ecosystem function, and crop production. Among all pollinators of the world, bees (Hymenoptera: Apoidea) constitute the major group in species number and importance, followed by hover flies (Diptera: Syrphidae). The Aegean constitutes one of the world’s hotspots for wild bee and other pollinator diversity including flies (mainly hover flies and b...

An ecological risk investigation of marine sediment from the northern Mediterranean coasts (Aegean Sea) using multiple methods of pollution determination.

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Tunca, Evren; Aydın, Mehmet; Şahin, Ülkü Alver

2018-03-01

The aim of this study is an assessment of metal pollution levels in Aegean Sea sediment. Sediment samples collected from 7 different locations (Yeniköy, Edremit, Ayvalık, Dikili, Aliağa, Hekimadası, and Ildır) along the northern Mediterranean region of Turkey were investigated for 11 elements (Cu, Fe, Zn, V, Cd, Ni, As, Pb, Mn, Co, and Cr). Graphite furnace atomic absorption spectrophotometry (GFAAS) and flame atomic absorption spectrophotometry (FAAS) were used for elemental analysis. The findings were evaluated with sediment assessment methods by taking two different values as a reference and then investigating the adverse biological effects of elemental profiles on living organisms. Pb, Mn, As, Cd, and Cr concentrations were within a moderate to significant range in terms of contamination factor [Formula: see text]), albeit varying according to reference and location. The most problematic region and elements regarding the enrichment factor (EF) was Ayvalık and As, Ni, Cu, Pb, Co, and Cd. However, according to the EF, the anthropogenic effect was not at an alarming level. This was further supported by the results of the geoaccumulation index (Igeo). The findings of the modified degree of contamination (mC d ) and the pollution load index (PLI) suggested that the accumulation was greatest in Ayvalık, and the least in Hekimadası and Ildır. The location with the highest elemental total toxic unit (ΣTU) was Edremit. The effect of the existing element profile on organisms was 21% in this location when the mean effect range-median quotient (m-ERM-q) was considered. As and Ni concentrations in all stations were found to be higher than threshold effect level (TEL) and Effect Range Low (ERL). Ni levels in Edremit exceeded the probable effect level (PEL) and Effect Range Median (ERM). Toxic unit (TU) values of these two elements in all stations ranged from 59.30 to 80.43%.

Distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea during summer.

Science.gov (United States)

Li, Jian-Long; Zhang, Hong-Hai; Yang, Gui-Peng

2017-07-01

Spatial distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea in July 2013 were investigated. This study is the first to report the concentrations of isoprene in the China marginal seas. Isoprene concentrations in the surface seawater during summer ranged from 32.46 to 173.5 pM, with an average of 83.62 ± 29.22 pM. Distribution of isoprene in the study area was influenced by the diluted water from the Yangtze River, which stimulated higher in-situ phytoplankton production of isoprene rather than direct freshwater input. Variations in isoprene concentrations were found to be diurnal, with high values observed during daytime. A significant correlation was observed between isoprene and chlorophyll a in the study area. Relatively higher isoprene concentrations were recorded at stations where the phytoplankton biomass was dominated by Chaetoceros, Skeletonema, Pennate-nitzschia, and Thalassiosira. Positive correlation was observed between isoprene and methyl iodide. In addition, sea-to-air fluxes of isoprene approximately ranged from 22.17 nmol m -2  d -1 -537.2 nmol m -2  d -1 , with an average of 161.5 ± 133.3 nmol m -2  d -1 . These results indicate that the coastal and shelf areas may be important sources of atmospheric isoprene. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recreating the South Sea Bubble : Lessons from an Experiment in Financial History

NARCIS (Netherlands)

Giusti, G.; Noussair, C.N.; Voth, H-J.

2013-01-01

Abstract: Major bubble episodes are rare events. In this paper, we examine what factors might cause some asset price bubbles to become very large. We recreate, in a laboratory setting, some of the specific institutional features investors in the South Sea Company faced in 1720. Several factors have

Bacterial community composition of South China Sea sediments through pyrosequencing-based analysis of 16S rRNA genes.

Science.gov (United States)

Zhu, Daochen; Tanabe, Shoko-Hosoi; Yang, Chong; Zhang, Weimin; Sun, Jianzhong

2013-01-01

Subseafloor sediments accumulate large amounts of organic and inorganic materials that contain a highly diverse microbial ecosystem. The aim of this study was to survey the bacterial community of subseafloor sediments from the South China Sea. Pyrosequencing of over 265,000 amplicons of the V3 hypervariable region of the 16S ribosomal RNA gene was performed on 16 sediment samples collected from multiple locations in the northern region of the South China Sea from depths ranging from 35 to 4000 m. A total of 9,726 operational taxonomic units (OTUs; between 695 and 2819 unique OTUs per sample) at 97% sequence similarity level were generated. In total, 40 bacterial phyla including 22 formally described phyla and 18 candidate phyla, with Proteobacteria, Firmicutes, Planctomycetes, Actinobacteria and Chloroflexi being most diverse, were identified. The most abundant phylotype, accounting for 42.6% of all sequences, belonged to Gammaproteobacteria, which possessed absolute predominance in the samples analyzed. Among the 18 candidate phyla, 12 were found for the first time in the South China Sea. This study provided a novel insight into the composition of bacterial communities of the South China Sea subseafloor. Furthermore, abundances and community similarity analysis showed that the compositions of the bacterial communities are very similar at phylum level at different depths from 35-4000 m.

Bacterial community composition of South China Sea sediments through pyrosequencing-based analysis of 16S rRNA genes.

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Daochen Zhu

Full Text Available BACKGROUND: Subseafloor sediments accumulate large amounts of organic and inorganic materials that contain a highly diverse microbial ecosystem. The aim of this study was to survey the bacterial community of subseafloor sediments from the South China Sea. METHODOLOGY/PRINCIPAL FINDINGS: Pyrosequencing of over 265,000 amplicons of the V3 hypervariable region of the 16S ribosomal RNA gene was performed on 16 sediment samples collected from multiple locations in the northern region of the South China Sea from depths ranging from 35 to 4000 m. A total of 9,726 operational taxonomic units (OTUs; between 695 and 2819 unique OTUs per sample at 97% sequence similarity level were generated. In total, 40 bacterial phyla including 22 formally described phyla and 18 candidate phyla, with Proteobacteria, Firmicutes, Planctomycetes, Actinobacteria and Chloroflexi being most diverse, were identified. The most abundant phylotype, accounting for 42.6% of all sequences, belonged to Gammaproteobacteria, which possessed absolute predominance in the samples analyzed. Among the 18 candidate phyla, 12 were found for the first time in the South China Sea. CONCLUSIONS: This study provided a novel insight into the composition of bacterial communities of the South China Sea subseafloor. Furthermore, abundances and community similarity analysis showed that the compositions of the bacterial communities are very similar at phylum level at different depths from 35-4000 m.

Variation of phytoplankton community structure from the Pearl River estuary to South China Sea.

Science.gov (United States)

Jiang, Zhao-Yu; Wang, You-Shao; Cheng, Hao; Sun, Cui-Ci; Wu, Mei-Lin

2015-10-01

The Pearl River is located in the northern part of South China Sea. The environment of the Pearl River estuary (PRE) is significantly impacted by nutrients from anthropogenic activities. Along the anthropogenic pollution gradient from the PRE to South China Sea, the phylogenetic diversity and biomass of phytoplankton was examined in relation to physic-chemical variables. The richness of rbcL gene was higher in the open sea than the estuary, while the concentration of chlorophyll a (Chl a) was higher in the estuary than in the open sea. The cluster analysis of the sequences data resulted in seven phytoplankton community types and the dominant species of phytoplankton changed from Cryptophytes and Diatoms to Prymnesiophytes and Diatoms along the gradient. The community structure of phytoplankton was shaped by nutrients and salinity. The phytoplankton biomass was significantly positively affected by phosphorus, nitrite and ammonium (P < 0.01) but negatively by salinity (P < 0.05); the phytoplankton diversity was highly positively affected by salinity (P < 0.05) but negatively by silicate and nitrate (P < 0.01; P < 0.05, respectively). Anthropogenic activities played a critical role in the phytoplankton distribution and biomass of the study area. Further research is necessary to reveal the influence mechanism of environmental factors on the phytoplankton.

Past 140-year environmental record in the northern South China Sea: evidence from coral skeletal trace metal variations.

Science.gov (United States)

Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A; Frost, Ray L

2014-02-01

About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986-1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. Copyright © 2013 Elsevier Ltd. All rights reserved.

Recent Multidisciplinary Research Initiatives and IODP Drilling in the South China Sea

Science.gov (United States)

Lin, J.; Li, C. F.; Wang, P.; Kulhanek, D. K.

2016-12-01

The South China Sea (SCS) is the largest low-latitude marginal sea in the world. Its formation and evolution are linked to the complex continental-oceanic tectonic interaction of the Eurasian, Pacific, and Indo-Australian plates. Despite its relatively small size and short history, the SCS has undergone nearly a complete Wilson cycle from continental break-up to seafloor spreading to subduction, serving as a natural laboratory for studying the linkages between tectonic, volcanic, and oceanic processes. The last several years have witnessed significant progress in investigation of the SCS through comprehensive research programs using multidisciplinary approaches and enhanced international collaboration. The International Ocean Discovery Program (IODP) Expedition 349 drilled and cored five sites in the SCS in 2014. The expedition successfully obtained the first basaltic rock samples of the SCS relict spreading center, discovered large and frequent deep-sea turbidity events, and sampled multiple seamount volcaniclastic layers. In addition, high-resolution near-seafloor magnetic surveys were conducted in the SCS with survey lines passing near some of the IODP drilling sites. Together the IODP drilling and deep-tow magnetic survey results confirmed, for the first time, that the entire SCS basin might have stopped seafloor spreading at similar ages in early Miocene, providing important constraints on marginal sea geodynamic models. In 2007, IODP Expeditions 367 and 368 will drill the northern margin of the SCS to investigate the mechanisms of rifting to spreading processes. Meanwhile, major progress in studying the SCS processes has also been made through comprehensive multidisciplinary programs, for example, the eight-year-long "South China Sea Deep" initiative, which also supports and encourages strong international collaboration. This presentation will highlight the recent multidisciplinary research initiatives in investigation of the SCS and the important role of

Hydrocarbon preservation conditions in Mesozoic–Paleozoic marine strata in the South Yellow Sea Basin

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Jie Liang

2017-11-01

Full Text Available In the South Yellow Sea Basin, Mesozoic–Paleozoic marine strata are generally well developed with large thickness, and they are characterized by multi-source and multi-stage hydrocarbon accumulation, providing a material basis for the formation of large-scale oil and gas fields. However, no substantial breakthrough has been made in this area. Based on previous research results, the complex tectonic pattern of this superimposed basin was formed by multi-stage tectonic movements and the favorable static conditions for hydrocarbon preservation were reworked or destroyed by later superimposition. Therefore, hydrocarbon preservation conditions are the key factors for restricting the breakthrough of marine oil and gas exploration in this area. In this paper, hydrocarbon preservation conditions of marine strata in the South Yellow Sea Basin were comprehensively analyzed from many aspects, such as tectonic movement, source conditions, caprock characteristics, magmatic activities, and hydrogeological and hydrogeochemical characteristics. It is indicated that the complex tectonic pattern of the South Yellow Sea Basin is resulted from tectonic events in multiple stages, and the development and evolution of regional source rocks are mainly controlled by two stages (i.e., the stable evolution stage of Mesozoic–Paleozoic marine basin and the Mesozoic–Cenozoic tectonic pattern transformation and basin formation stage, so the characteristics of differential oil and gas preservation are presented. Besides, better marine hydrocarbon preservation preconditions in this area are weaker tectonic reworking, development of high-quality thick source rocks, good vertical sealing capacity of caprocks, weaker magmatic activity and confined hydrogeological conditions. It is concluded that the Laoshan Uplift in the central part of the South Yellow Sea Basin is structurally stable with weaker faulting and magmatic activities, so it is better in oil and gas preservation

Genetic structuring of European anchovy (Engraulis encrasicolus) populations through mitochondrial DNA sequences.

Science.gov (United States)

Keskin, Emre; Atar, Hasan Huseyin

2012-04-01

Mitochondrial DNA sequence variation in 655 bpfragments of the cytochrome oxidase c subunit I gene, known as the DNA barcode, of European anchovy (Engraulis encrasicolus) was evaluated by analyzing 1529 individuals representing 16 populations from the Black Sea, through the Marmara Sea and the Aegean Sea to the Mediterranean Sea. A total of 19 (2.9%) variable sites were found among individuals, and these defined 10 genetically diverged populations with an overall mean distance of 1.2%. The highest nucleotide divergence was found between samples of eastern Mediterranean and northern Aegean (2.2%). Evolutionary history analysis among 16 populations clustered the Mediterranean Sea clades in one main branch and the other clades in another branch. Diverging pattern of the European anchovy populations correlated with geographic dispersion supports the genetic structuring through the Black Sea-Marmara Sea-Aegean Sea-Mediterranean Sea quad.

Spectral Interpretation of Wave-vortex Duality in Northern South China Sea

Science.gov (United States)

Cao, H.; Jing, Z.; Yan, T.

2017-12-01

The mesoscale to submesocale oceanic dynamics are characterized by a joint effect of vortex and wave component, which primarily declares the partition between geostrophic balanced and unbalanced flows. The spectral method is a favorable approach that can afford the muti-scale analysis. This study investigates the characteristics of horizontal wavenumber spectra in Nothern South China Sea using orbital altimeter data (SARA/AltiKa), 13-yr shipboard ADCP (Acoustic Doppler Current Profiler) measurements (2014-2016), and a high-resolution numerical simulation (llc4320 Mitgcm). The observed SSH (sea surface height) spectrum presents a conspicuous transition at scales of 50-100 km, which clearly shows the inconsistency with geostrophic balance. The Helmholtz decomposition separating the wave and vortex energy for the spectra of ADCP and numerical model data shows that ageostrophic flows should be responsible for the spectral discrepancy with the QG (qusi-geostrophic) turbulence theory. Generally, it is found that inertia-gravity waves (including internal tides) govern the significant kinetic energy in the submesoscale range in Northern South China Sea. More specific analysis suggests that the wave kinetic energy can extend to a large scale of 500 km or more from the zonal velocity spectra at the left-center of Luzon Strait, which appears to be dominated by inertia-gravity waves likely emitted by the intrusion of the west pacific at Luzon Strait. Instead, the development of eddy kinetic energy at this place is strictly constrained by the width of the strait.

Interannual variation of the South China Sea circulation during winter: intensified in the southern basin

Science.gov (United States)

Zu, Tingting; Xue, Huijie; Wang, Dongxiao; Geng, Bingxu; Zeng, Lili; Liu, Qinyan; Chen, Ju; He, Yunkai

2018-05-01

Surface geostrophic current derived from altimetry remote sensing data, and current profiles observed from in-situ Acoustic Doppler Current Profilers (ADCP) mooring in the northern South China Sea (NSCS) and southern South China Sea (SSCS) are utilized to study the kinetic and energetic interannual variability of the circulation in the South China Sea (SCS) during winter. Results reveal a more significant interannual variation of the circulation and water mass properties in the SSCS than that in the NSCS. Composite ananlysis shows a significantly reduced western boundary current (WBC) and a closed cyclonic eddy in the SSCS at the mature phase of El Niño event, but a strong WBC and an unclosed cyclonic circulation in winter at normal or La Niña years. The SST is warmer while the subsurface water is colder and fresher in the mature phase of El Niño event than that in the normal or La Niña years in the SSCS. Numerical experiments and energy analysis suggest that both local and remote wind stress change are important for the interannual variation in the SSCS, remote wind forcing and Kuroshio intrusion affect the circulation and water mass properties in the SSCS through WBC advection.

Bioprospecting of Novel and Bioactive Compounds from Marine Actinomycetes Isolated from South China Sea Sediments.

Science.gov (United States)

Yang, Na; Song, Fuhang

2018-02-01

Marine actinomycetes are less investigated compared to terrestrial strains as potential sources of natural products. To date, few investigations have been performed on culturable actinomycetes associated with South China Sea sediments. In the present study, twenty-eight actinomycetes were recovered from South China Sea sediments after dereplication by traditional culture-dependent method. The 16S rRNA gene sequences analyses revealed that these strains related to five families and seven genera. Twelve representative strains possessed at least one of the biosynthetic genes coding for polyketide synthase I, II, and nonribosomal peptide synthetase. Four strains had anti-Mycobacterium phlei activities and five strains had activities against methicillin-resistant Staphylococcus aureus. 10 L-scale fermentation of strains Salinispora sp. NHF45, Nocardiopsis sp. NHF48, and Streptomyces sp. NHF86 were carried out for novel and bioactive compounds discovery. Finally, we obtained a novel α-pyrone compound from marine Nocardiopsis sp. NHF48, an analogue of paulomenol from marine Streptomyces sp. NHF86 and a new source of rifamycin B, produced by Salinispora sp. NHF45. The present study concluded that marine actinomycetes, which we isolated from South China Sea sediments, will be a suitable source for the development of novel and bioactive compounds.

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

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Z. KOKKINI

2014-12-01

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

The Aegean crises’ effects on social behaviour. Stereotyping the alterity: the case of the Greek printed media (1974-1996)

OpenAIRE

Oana Camelia Stroescu

2011-01-01

The paper revisits the main characteristics of the Greek-Turkish relations, taking as its point of departure the Greek-Turkish dispute over the Aegean continental shelf (1974-1996), as in that period, a list of mutual grievances on issues of high politics still remained intact. The article examines how the main Greek Dailies: Kathimerini, Eleftheros Typos, Ta Nea, Makedonia and Rizospastis covered Aegean crises of 1976, 1987 and 1996. An effort is made to analyze the position of the above-men...

Prediction of South China sea level using seasonal ARIMA models

Science.gov (United States)

Fernandez, Flerida Regine; Po, Rodolfo; Montero, Neil; Addawe, Rizavel

2017-11-01

Accelerating sea level rise is an indicator of global warming and poses a threat to low-lying places and coastal countries. This study aims to fit a Seasonal Autoregressive Integrated Moving Average (SARIMA) model to the time series obtained from the TOPEX and Jason series of satellite radar altimetries of the South China Sea from the year 2008 to 2015. With altimetric measurements taken in a 10-day repeat cycle, monthly averages of the satellite altimetry measurements were taken to compose the data set used in the study. SARIMA models were then tried and fitted to the time series in order to find the best-fit model. Results show that the SARIMA(1,0,0)(0,1,1)12 model best fits the time series and was used to forecast the values for January 2016 to December 2016. The 12-month forecast using SARIMA(1,0,0)(0,1,1)12 shows that the sea level gradually increases from January to September 2016, and decreases until December 2016.

Methane in the South China Sea and the Western Philippine Sea

Science.gov (United States)

Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto V.; DelValls, T. Angel; Chang, Yu-Chang

2017-03-01

Approximately 700 water samples from the South China Sea (SCS) and 300 water samples from the western Philippine Sea (wPS) were collected during eight cruises from August 2003 to July 2007 to determine methane (CH4) distributions from the surface to a depth of 4250 m. The surface CH4 concentrations exceeded atmospheric equilibrium, both in the SCS and the wPS, and the concentrations were 4.5±3.6 and 3.0±1.2 nmol L-1, respectively. The sea-to-air fluxes were calculated, and the SCS and the wPS were found to emit CH4 to the atmosphere at 8.6±6.4 μmol m-2 d-1 and 4.9±4.9 μmol m-2 d-1, respectively. In the SCS, CH4 emissions were higher over the continental shelf (11.0±7.4 μmol m-2 d-1) than over the deep ocean (6.1±6.0 μmol m-2 d-1), owing to greater biological productivity and closer coupling with the sediments on the continental shelf. The SCS emitted 30.1×106 mol d-1 CH4 to the atmosphere and exported 1.82×106 mol d-1 CH4 to the wPS. The concentrations of both CH4 and chlorophyll a were high in the 150 m surface layer of the wPS, but were not significantly correlated with each other. CH4 concentrations generally declined with increasing depth below the euphotic zone but remained constant below 1,000 m, both in the SCS and the wPS. Some high CH4 concentrations were observed at mid-depths and bottom waters in the SCS, and were most likely caused by the release of CH4 from gas hydrates or gas seepage.

Immunohistochemical localization of CYP1A, vitellogenin and Zona radiata proteins in the liver of swordfish (Xiphias gladius L.) taken from the Mediterranean Sea, South Atlantic, South Western Indian and Central North Pacific Oceans

International Nuclear Information System (INIS)

Desantis, S.; Corriero, A.; Cirillo, F.; Deflorio, M.; Brill, R.; Griffiths, M.; Lopata, A.L.; Serna, J.M. de la; Bridges, C.R.; Kime, D.E.; De Metrio, G.

2005-01-01

Cytochrome P4501A (CYP1A) monoxygenase, vitellogenin (Vtg) and Zona radiata proteins (Zrp) are frequently used as biomarkers of fish exposure to organic contaminants. In this work, swordfish liver sections obtained from the Mediterranean Sea, the South African coasts (South Atlantic and South Western Indian Oceans) and the Central North Pacific Ocean were immunostained with antisera against CYP1A, Zrp, and Vtg. CYP1A induction was found in hepatocytes, epithelium of the biliary ductus and the endothelium of large blood vessels of fish from the Mediterranean Sea and South African waters, but not from the Pacific Ocean. Zrp and Vtg were immunolocalized in hepatocytes of male swordfish from the Mediterranean Sea and from South African waters. Plasma Dot-Blot analysis, performed in Mediterranean and Pacific specimens, revealed the presence of Zrp and Vtg in males from Mediterranean but not from Pacific. These results confirm previous findings about the potential exposure of Mediterranean swordfish to endocrine, disrupting chemicals and raise questions concerning the possible presence of xenobiotic contaminants off the Southern coasts of South Africa in both the South Atlantic and South Western Indian Oceans

Anthropozoonotic Endoparasites in Free-Ranging "Urban" South American Sea Lions (Otaria flavescens).

Science.gov (United States)

Hermosilla, Carlos; Silva, Liliana M R; Navarro, Mauricio; Taubert, Anja

2016-01-01

The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging "urban" colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

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

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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.

Levels of endocrine disrupting compounds in South China Sea.

Science.gov (United States)

Zhang, Li-Peng; Wang, Xin-Hong; Ya, Miao-Lei; Wu, Yu-Ling; Li, Yong-Yu; Zhang, Zu-lin

2014-08-30

The occurrence of estrogens in the aquatic environment has become a major concern worldwide because of their strong endocrine disrupting potency. In this study, concentrations of four estrogenic compounds, estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), estriol (E3) were determined with liquid chromatography-tandem mass spectrometry analyses in surface water from South China Sea, and distributions and potential risks of their estrogenic activity were assessed. The estrogenic compounds E1, E2 and E3 were detected in most of the samples, with their concentrations up to 11.16, 3.71 and 21.63 ng L(-1). However, EE2 was only detected in 3 samples. Causality analysis, EEQ values from chemical analysis identified E2 as the main responsible compounds. Based on the EEQ values in the surface water, high estrogenic risks were in the coastal water, and low estrogenic risks in the open sea. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Empirical prediction of the onset dates of South China Sea summer monsoon

Science.gov (United States)

Zhu, Zhiwei; Li, Tim

2017-03-01

The onset of South China Sea summer monsoon (SCSSM) signifies the commencement of the wet season over East Asia. Predicting the SCSSM onset date is of significant importance. In this study, we establish two different statistical models, namely the physical-empirical model (PEM) and the spatial-temporal projection model (STPM) to predict the SCSSM onset. The PEM is constructed from the seasonal prediction perspective. Observational diagnoses reveal that the early onset of the SCSSM is preceded by (a) a warming tendency in middle and lower troposphere (850-500 hPa) over central Siberia from January to March, (b) a La Niña-like zonal dipole sea surface temperature pattern over the tropical Pacific in March, and (c) a dipole sea level pressure pattern with negative center in subtropics and positive center over high latitude of Southern Hemisphere in January. The PEM built on these predictors achieves a cross-validated reforecast temporal correlation coefficient (TCC) skill of 0.84 for the period of 1979-2004, and an independent forecast TCC skill of 0.72 for the period 2005-2014. The STPM is built on the extended-range forecast perspective. Pentad data are used to predict a zonal wind index over the South China Sea region. Similar to PEM, the STPM is constructed using 1979-2004 data. Based on the forecasted zonal wind index, the independent forecast of the SCSSM onset dates achieves a TCC skill of 0.90 for 2005-2014. The STPM provides more detailed information for the intraseasonal evolution during the period of the SCSSM onset (pentad 25-35). The two models proposed herein are expected to facilitate the real-time prediction of the SCSSM onset.

Impacts of South East Biomass Burning on local air quality in South China Sea

Science.gov (United States)

Wai-man Yeung, Irene; Fat Lam, Yun; Eniolu Morakinyo, Tobi

2016-04-01

Biomass burning is a significant source of carbon monoxide and particulate matter, which is not only contribute to the local air pollution, but also regional air pollution. This study investigated the impacts of biomass burning emissions from Southeast Asia (SEA) as well as its contribution to the local air pollution in East and South China Sea, including Hong Kong and Taiwan. Three years (2012 - 2014) of the Hybrid Single Particle Lagrangian-Integrated Trajectory (HYSPLIT) with particles dispersion analyses using NCEP (Final) Operational Global Analysis data (FNL) data (2012 - 2014) were analyzed to track down all possible long-range transport from SEA with a sinking motion that worsened the surface air quality (tropospheric downwash from the free troposphere). The major sources of SEA biomass burning emissions were first identified using high fire emissions from the Global Fire Emission Database (GFED), followed by the HYSPLIT backward trajectory dispersion modeling analysis. The analyses were compared with the local observation data from Tai Mo Shan (1,000 msl) and Tap Mun (60 msl) in Hong Kong, as well as the data from Lulin mountain (2,600 msl) in Taiwan, to assess the possible impacts of SEA biomass burning on local air quality. The correlation between long-range transport events from the particles dispersion results and locally observed air quality data indicated that the background concentrations of ozone, PM2.5 and PM10 at the surface stations were enhanced by 12 μg/m3, 4 μg/m3 and 7 μg/m3, respectively, while the long-range transport contributed to enhancements of 4 μg/m3, 4 μg/m3 and 8 μg/m3 for O3, PM2.5 and PM10, respectively at the lower free atmosphere.

Ectoparasites from the South American sea lion (Otaria flavescens from Peruvian coast

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Luis A. Gomez-Puerta

2015-10-01

Full Text Available Two species of ectoparasites were collected from a South American sea lion (Otaria flavescens found stranded on the beaches of Chorrillos in Lima, Peru. The ectoparasites were identified as Antarctophthirus microchir (Phthiraptera and Orthohalarachne attenuata (Acari. Some morphological characteristics are described in this report. The finding of these ectoparasites is the first records in Peru.

A cold pool south of Indo-Sri Lanka channel and its intrus on into the southeastern Arabian Sea during winter

Digital Repository Service at National Institute of Oceanography (India)

Rao, R.R.; GirishKumar, M.S.; Ravichandran, M.; Gopalakrishna, V.V.; Pankajakshan, T.

northwestward by the Maldives Island Chain. The resultant near-surface circulation also appears to strengthen the amplitude of the near-surface thermal inversions observed in the SouthEastern Arabian Sea (SEAS)...

Difference of nitrogen-cycling microbes between shallow bay and deep-sea sediments in the South China Sea.

Science.gov (United States)

Yu, Tiantian; Li, Meng; Niu, Mingyang; Fan, Xibei; Liang, Wenyue; Wang, Fengping

2018-01-01

In marine sediments, microorganisms are known to play important roles in nitrogen cycling; however, the composition and quantity of microbes taking part in each process of nitrogen cycling are currently unclear. In this study, two different types of marine sediment samples (shallow bay and deep-sea sediments) in the South China Sea (SCS) were selected to investigate the microbial community involved in nitrogen cycling. The abundance and composition of prokaryotes and seven key functional genes involved in five processes of the nitrogen cycle [nitrogen fixation, nitrification, denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonia oxidation (anammox)] were presented. The results showed that a higher abundance of denitrifiers was detected in shallow bay sediments, while a higher abundance of microbes involved in ammonia oxidation, anammox, and DNRA was found in the deep-sea sediments. Moreover, phylogenetic differentiation of bacterial amoA, nirS, nosZ, and nrfA sequences between the two types of sediments was also presented, suggesting environmental selection of microbes with the same geochemical functions but varying physiological properties.

Microseismicity in the SE Aegean using data of he temporary EGELADOS network

Science.gov (United States)

Brüstle, Andrea; Küperkoch, Ludger; Meier, Thomas; Friederich, Wolfgang; Egelados Working Group

2010-05-01

The temporary broadband EGELADOS network covered the entire Hellenic Subduction Zone from October 2005 to April 2007. Seismic events are detected and identified by an STA/LTA-trigger and a grid-search algorithm, where relative travel times of pre-defined masterevents are compared to observed differential trigger times. Because of the high seismicity, we will focus on this poster on the south-eastern part of the Hellenic Subduction Zone including the forearc around Rhodes, Karpathos and Kassos and the volcanic arc around Nisyros. In addition, the considered region covers the transition zone from the Aegean to the Anatolian microplates at the west coast of Turkey. In this region we have located more than 3500 local earthquakes in 13 months of the network. Microseismicity down to a magnitude of about ML 1.8 is detected completely. In regions with an increased station density, microseismicity may be observed completely down to magnitudes of ML 1. High shallow microseismicity is observed in the forearc with clusters southeast of Crete (Ptolemy trench), south of Karpathos and southwest of Amorgos within the volcanic arc. A continuous seismically active zone strikes along the EW trending rift of the Gulf of Goekova to western Kos and changes its direction to NS by crossing the volcanic island Nisyros and extruding into the forearc near Kassos. Intermediate depth seismicity of the subducting slab is located in the volcanic arc between Astypalea and Tilos. The strong attenuation of the S-waves of intermediate depth events points to low Q in the mantle wedge above the subducting African lithosphere. In contrast, S-waves propagating within the slab from the source to the stations in the forearc are much less attenuated.

Thermoluminescence dating of abyssal deposits in the north region of the South China Sea

International Nuclear Information System (INIS)

Peng Xiaoxian

1988-01-01

The ages of abyssal deposits have been studied by TL dating. The ages of the deposits from the wells Weima 1, 5 and 6 at the slope in the north of the South China Sea are 36,100 and 128 thousand years respectively

Contrasting Photophysiological Characteristics of Phytoplankton Assemblages in the Northern South China Sea.

Science.gov (United States)

Jin, Peng; Gao, Guang; Liu, Xin; Li, Futian; Tong, Shanying; Ding, Jiancheng; Zhong, Zhihai; Liu, Nana; Gao, Kunshan

2016-01-01

The growth of phytoplankton and thus marine primary productivity depend on photophysiological performance of phytoplankton cells that respond to changing environmental conditions. The South China Sea (SCS) is the largest marginal sea of the western Pacific and plays important roles in modulating regional climate and carbon budget. However, little has been documented on photophysiological characteristics of phytoplankton in the SCS. For the first time, we investigated photophysiological characteristics of phytoplankton assemblages in the northern South China Sea (NSCS) using a real-time in-situ active chlorophyll a fluorometry, covering 4.0 × 105 km2. The functional absorption cross section of photosystem II (PSII) in darkness (σPSII) or under ambient light (σPSII') (A2 quanta-1) increased from the surface to deeper waters at all the stations during the survey period (29 July to 23 August 2012). While the maximum (Fv/Fm, measured in darkness) or effective (Fq'/Fm', measured under ambient light) photochemical efficiency of PSII appeared to increase with increasing depth at most stations, it showed inverse relationship with depth in river plume areas. The functional absorption cross section of PSII changes could be attributed to light-adapted genotypic feature due to niche-partition and the alteration of photochemical efficiency of PSII could be attributed to photo-acclimation. The chlorophyll a fluorometry can be taken as an analog to estimate primary productivity, since areas of higher photochemical efficiency of PSII coincided with those of higher primary productivity reported previously in the NSCS.

Long-term spatiotemporal trends and health risk assessment of oyster arsenic levels in coastal waters of northern South China Sea.

Science.gov (United States)

Wang, Xuefeng; Wang, Lifei; Jia, Xiaoping; Jackson, Donald A

2017-09-01

Long-term spatiotemporal trends and health risk assessment of oyster arsenic levels in the coastal waters of northern South China Sea were investigated in order to help improve the quality and safety control and sustainable aquaculture for mollusks in China. Cultured oysters (Crassostrea rivularis) collected from the waters of 23 bays, harbors, and estuaries along the coast of northern South China Sea from 1989 to 2012 were examined for spatial patterns and long-term temporal trends of oyster arsenic levels. Single-factor index and health risk assessment were used to quantify arsenic exposure to human health through oyster consumption. Overall, arsenic was detected in 97.4% of the oyster samples, and oyster arsenic levels were non-detectable-2.51 mg/kg with an average of 0.63 ± 0.54 mg/kg. Oyster arsenic levels in the coastal waters of northern South China Sea showed an overall decline from 1989 to 2012, remained relatively low since 2005, and slightly increased after 2007. Oyster arsenic levels in Guangdong coastal waters were much higher with more variation than in Guangxi and Hainan coastal waters, and the long-term trends of oyster arsenic levels in Guangdong coastal waters dominated the overall trends of oyster arsenic levels in the coastal waters of northern South China Sea. Within Guangdong Province, oyster arsenic levels were highest in east Guangdong coastal waters, followed by the Pearl River estuary and west Guangdong coastal waters. Single-factor index ranged between 0.27 and 0.97, and average health risk coefficient was 3.85 × 10 -5 , both suggesting that oyster arsenic levels in northern South China Sea are within the safe range for human consumption. However, long-term attention should be given to seafood market monitoring in China and the risk of arsenic exposure to human health through oyster consumption.

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

Science.gov (United States)

Draganits, E.

2012-04-01

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

Storm surges in the Singapore Strait due to winds in the South China Sea

Digital Repository Service at National Institute of Oceanography (India)

Tkalich, P.; Vethamony, P.; Babu, M.T.; Malanotte-Rizzoli, P.

on the north, Karimata Strait on the south, east cost of Peninsular Malaysia on the west, and break of Sunda Shelf on the east, could experience positive or negative SLAs depending on the wind direction and speed. Strong sea level surges during NE monsoon...

Sources of new nitrogen in the Vietnamese upwelling region of the South China Sea

DEFF Research Database (Denmark)

Bombar, Deniz; Dippner, Joachim W.; Doan, Hai Nhu

2010-01-01

In the South China Sea, the southwest monsoon between June and September induces upwelling off the southern central Vietnamese coast. During field campaigns in July 2003 and 2004 we evaluated the importance of nitrate and nitrogen fixation as sources of new nitrogen for phytoplankton primary...

The Kuroshio exchange with the South and East China Seas

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T. Matsuno

2009-08-01

Full Text Available The Kuroshio flows along the edges of the marginal East Asian seas such as the South China Sea (SCS and East China Sea (ECS. Exchanges of materials and energy between the Kuroshio and the marginal seas partly control the environments of the marginal seas. In particular, saline water from the Kuroshio maintains certain salinity in the shelf water in the ECS. Nutrients from the subsurface of the Kuroshio may influence primary production on the shelf. We summarize how the Kuroshio comes into contact with the shelf water or marginal seas, describing phenomena related to the exchange between the Kuroshio and the ECS along with the SCS, using reports in the literature along with original data. The Kuroshio tends to intrude into the SCS through the Luzon Strait in various manners such as direct intrusion, associated with eddies and as a loop current. The Kuroshio intrusion into the shelf region of the ECS has distinct seasonal variation and the Taiwan Warm Current plays a significant role in the determination of water properties in the outer shelf associated with the Kuroshio intrusion. We then examine physical processes related to the interaction between the Kuroshio and shelf water. Interaction between the Kuroshio and the bottom topography is an important process in the control of the exchange around the shelf break. Vertical mixing and frontal eddies are also important factors that control the water exchange and formation of water masses in the outer shelf. Wind stress plays a significant role in the exchange with a rather event-like manner. To determine the source of the water masses, chemical tracers could be powerful tools and it is suggested that a significant part of the shelf water consists of Kuroshio intermediate water.

Magnetic minerals in three Asian rivers draining into the South China Sea: Pearl, Red, and Mekong Rivers

Science.gov (United States)

Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

2016-05-01

The use of the marine sedimentary magnetic properties, as tracers for changes in precipitation rate and in oceanic water masses transport and exchanges, implies to identify and to characterize the different sources of the detrital fraction. This is of particular importance in closed and/or marginal seas such as the South China Sea. We report on the magnetic properties of sedimentary samples collected in three main Asian rivers draining into the South China Sea: the Pearl, Red, and Mekong Rivers. The geological formations as well as the present climatic conditions are different from one catchment to another. The entire set of performed magnetic analyses (low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis parameters, FORC diagrams, and low-temperature magnetic measurements) allow us to identify the magnetic mineralogy and the grain-size distribution when magnetite is dominant. Some degree of variability is observed in each basin, illustrating different parent rocks and degree of weathering. On average it appears that the Pearl River is rich in magnetite along the main stream while the Mekong River is rich in hematite. The Red River is a mixture of the two. Compared to clay mineral assemblages and major element contents previously determined on the same samples, these new findings indicate that the magnetic fraction brings complementary information of great interest for environmental reconstructions based on marine sediments from the South China Sea.

Methylmercury in fish from the South China Sea: geographical distribution and biomagnification.

Science.gov (United States)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-12-15

We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ(15)N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log10MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log10(MeHg) and δ(15)N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnetic Properties of the Rivers Feeding the South China Sea: a Critical Step for Understanding the Paleo-Marine Records.

Science.gov (United States)

Kissel, C.; Liu, Z.; Wandres, C.

2014-12-01

In order to use the magnetic properties of marine sediments as a tracer for past changes in the precipitation rate on land and in oceanic water masses transport and exchanges in the South China Sea, we identify and characterize the different sources of the detrital fraction among which the magnetic particles. This work is presently conducted in the framework of the Franco-Chinese LIA-MONOCL Thanks to the Westpac project, we had access to sediments collected in the deltas of the main rivers feeding the South China Sea from about 25°N to the equator. This is represented on the Asian continent by the Pearl river, the Red River, the Mekong river, by Malaysia, Sumatra and Borneo regions with minor rivers but also contributing to the South China Sea, and finally by Luzon and Taiwan. The geological formations contributing to the river sediment discharges are different from one catchment basin to another as well as the present climatic conditions. The magnetic analyses consist in the analysis of low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of 3-axes IRM, hysteresis parameters, and FORC diagrams. The obtained parameters all together allow us to define the nature of the magnetic grains and their grain size distribution when magnetite is dominant. Some degree of variability is observed at the river mouths, illustrating different geological sources at the local/regional scale. As an average, it appears that the Southern basin of the South China Sea is surrounded by regions richer in high coercivity magnetic minerals than the northern basin. This mineral is identified as hematite while magnetites (and sulfides) are more abundant in the north. These results are complementary to the clay mineral assemblages previously determined on the same samples. The first steps of a similar study conducted on marine core-tops well distributed in the South China Sea will also be illustrated.

Seasonal variability of thermal fronts in the northern South China Sea from satellite data

Science.gov (United States)

Wang, Dongxiao; Liu, Yun; Qi, Yiquan; Shi, Ping

The 8-year (1991-1998) Pathfinder sea surface temperature data have been applied here to produce the objectively derived seasonality of the oceanic thermal fronts in the northern South China Sea from 17°N to 25°N. Several fronts have been clearly distinguished, namely, Fujian and Guangdong Coastal Water, Pear River Estuary Coastal, Taiwan Bank, Kuroshio Intrusion, Hainan Island East Coast and Tonkin Gulf Coastal fronts. The frontal patterns in winter, spring and summer are quite similar, whereas individual fronts display different modes of seasonal variability due to different mechanisms favoring those fronts.

Surveillance at sea: The transactional politics of border control in the Aegean

NARCIS (Netherlands)

H. Dijstelbloem (Huub); R. van Reekum (Rogier); W. Schinkel (Willem)

2017-01-01

textabstractThe relationship between vision and action is a key element of both practices and conceptualizations of border surveillance in Europe. This article engages with what we call the ‘operative vision’ of surveillance at sea, specifically as performed by the border control apparatus in the

First characterization of bacterial pathogen, Vibrio alginolyticus, for Porites andrewsi White syndrome in the South China Sea.

Science.gov (United States)

Zhenyu, Xie; Shaowen, Ke; Chaoqun, Hu; Zhixiong, Zhu; Shifeng, Wang; Yongcan, Zhou

2013-01-01

White syndrome, a term for scleractinian coral disease with progressive tissue loss, is known to cause depressed growth and increased morality of coral reefs in the major oceans around the world, and the occurrence of this disease has been frequently reported in the past few decades. Investigations during April to September in both 2010 and 2011 identified widespread Porites andrewsi White syndrome (PAWS) in Xisha Archipelago, South China Sea. However, the causes and etiology of PAWS have been unknown. A transmission experiment was performed on P. andrewsi in the Qilianyu Subgroup (QLY). The results showed that there was a significant (P ≤ 0.05) difference between test and control groups after 28 days if the invalid replicates were excluded. Rates of tissue loss ranged from 0.90-10.76 cm(2) d(-1) with a mean of 5.40 ± 3.34 cm(2) d(-1) (mean ± SD). Bacterial strains were isolated from the PAWS corals at the disease outbreak sites in QLY of the Xisha Archipelago, South China Sea, and included in laboratory-based infection trials to satisfy Koch's postulates for establishing causality. Following exposure to bacterial concentrations of 10(5) cells mL(-1), the infected colonies exhibited similar signs to those observed in the field. Using phylogenetic 16S rRNA gene analysis, classical phenotypic trait comparison, Biolog automatic identification system, MALDI-TOF mass spectrometry and MALDI Biotyper method, two pathogenic strains were identified as Vibrio alginolyticus . This is the first report of V. alginolyticus as a pathogenic agent of PAWS in the South China Sea. Our results point out an urgent need to develop sensitive detection methods for V. alginolyticus virulence strains and robust diagnostics for coral disease caused by this and Vibrio pathogenic bacterium in the South China Sea.

Dynamics of the water circulations in the southern South China Sea and its seasonal transports

DEFF Research Database (Denmark)

Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

2016-01-01

-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast......A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re...... of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic...

The diplomacy of scientific research in the South China Sea: the case of join to oceanographic marine scientific research expedition between Vietnam and the Philippines

Science.gov (United States)

Satyawan, I. A.

2018-03-01

The South China Sea is one of the hot-spot areas in the world. This area is claimed by China, Malaysia, Brunei, Taiwan, Vietnam and the Philippines. It also noted, the South China Sea is rich in biodiversity as well as oil and gas. On the other side, environmental degradation is still happening in the South China Sea due to the reluctance of surrounding states to conduct a preservation program and mitigating action on climate change effects. Joint Oceanographic Marine Scientific Research Expedition between Vietnam and the Philippines is a breakthrough to start collaboration actions as well as to conduct Science Diplomacy.

The ordered network structure of M {>=} 6 strong earthquakes and its prediction in the Jiangsu-South Yellow Sea region

Energy Technology Data Exchange (ETDEWEB)

Men, Ke-Pei [Nanjing Univ. of Information Science and Technology (China). College of Mathematics and Statistics; Cui, Lei [California Univ., Santa Barbara, CA (United States). Applied Probability and Statistics Dept.

2013-05-15

The the Jiangsu-South Yellow Sea region is one of the key seismic monitoring defence areas in the eastern part of China. Since 1846, M {>=} 6 strong earthquakes have showed an obvious commensurability and orderliness in this region. The main orderly values are 74 {proportional_to} 75 a, 57 {proportional_to} 58 a, 11 {proportional_to} 12 a, and 5 {proportional_to} 6 a, wherein 74 {proportional_to} 75 a and 57 {proportional_to} 58 a with an outstanding predictive role. According to the information prediction theory of Wen-Bo Weng, we conceived the M {>=} 6 strong earthquake ordered network structure in the South Yellow Sea and the whole region. Based on this, we analyzed and discussed the variation of seismicity in detail and also made a trend prediction of M {>=} 6 strong earthquakes in the future. The results showed that since 1998 it has entered into a new quiet episode which may continue until about 2042; and the first M {>=} 6 strong earthquake in the next active episode will probably occur in 2053 pre and post, with the location likely in the sea area of the South Yellow Sea; also, the second and the third ones or strong earthquake swarm in the future will probably occur in 2058 and 2070 pre and post. (orig.)

Assessment of Wave Energy in the South China Sea Based on GIS Technology

Directory of Open Access Journals (Sweden)

Gang Lin

2017-01-01

Full Text Available China is now the world’s largest user of coal and also has the highest greenhouse gas emissions associated with the mining and use of coal. Under today’s enormous pressures of the growing shortage of conventional energy sources and the need for emission reductions, the search for clean energy is the most effective strategy to address the energy crisis and global warming. This study utilized satellite remote sensing technology, geographic information system (GIS technology, and simulated wave data for the South China Sea. The characteristic features of the wave energy were obtained by analysis through the wave resource assessment formula and the results were stored in a GIS database. Software for the evaluation of wave energy in the South China Sea was written. The results should provide accurate, efficient references for wave energy researchers and decision-makers. Based on a 24-year WW3 model simulation wave data and GIS technology, this study presented the characteristic of the wave energy in the SCS; results demonstrated that the SCS has the feasibility and viability for wave energy farming.

Anthropozoonotic Endoparasites in Free-Ranging “Urban” South American Sea Lions (Otaria flavescens

Directory of Open Access Journals (Sweden)

Carlos Hermosilla

2016-01-01

Full Text Available The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium. Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

Anthropozoonotic Endoparasites in Free-Ranging “Urban” South American Sea Lions (Otaria flavescens)

Science.gov (United States)

Silva, Liliana M. R.; Navarro, Mauricio; Taubert, Anja

2016-01-01

The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health. PMID:27051860

Acceleration of modern acidification in the South China Sea driven by anthropogenic CO2

Science.gov (United States)

Liu, Yi; Peng, Zicheng; Zhou, Renjun; Song, Shaohua; Liu, Weiguo; You, Chen-Feng; Lin, Yen-Po; Yu, Kefu; Wu, Chung-Che; Wei, Gangjian; Xie, Luhua; Burr, George S.; Shen, Chuan-Chou

2014-01-01

Modern acidification by the uptake of anthropogenic CO2 can profoundly affect the physiology of marine organisms and the structure of ocean ecosystems. Centennial-scale global and regional influences of anthropogenic CO2 remain largely unknown due to limited instrumental pH records. Here we present coral boron isotope-inferred pH records for two periods from the South China Sea: AD 1048–1079 and AD 1838–2001. There are no significant pH differences between the first period at the Medieval Warm Period and AD 1830–1870. However, we find anomalous and unprecedented acidification during the 20th century, pacing the observed increase in atmospheric CO2. Moreover, pH value also varies in phase with inter-decadal changes in Asian Winter Monsoon intensity. As the level of atmospheric CO2 keeps rising, the coupling global warming via weakening the winter monsoon intensity could exacerbate acidification of the South China Sea and threaten this expansive shallow water marine ecosystem. PMID:24888785

A new species of Pectinaria (Annelida, Pectinariidae), with a key to pectinariids from the South China Sea.

Science.gov (United States)

Zhang, Jinghuai; Qiu, Jian-Wen

2017-01-01

Pectinariidae is a family of polychaetes building unique ice-cream cone shaped sandy tubes. Pectinaria torquata sp. n. (Pectinariidae) is described from the coastal waters of the northern South China Sea. This new species can be distinguished from all other 25 recognized species in the genus by a combination of characters: 16 chaetigers; 26-32 cirri in the cephalic veil; 11-12 pairs of cephalic spines; uncini with major teeth arranged in two rows, each with 7-8 major teeth; presence of a dorsal posterior lobe on segments 2 and 20; 4-5 pairs of curved scaphal hooks; and an anal flap with a crenulated margin. A key to all recognized pectinariids in the South China Sea is provided.

The characteristics of heat flow in the Shenhu gas hydrate drilling area, northern South China Sea

Science.gov (United States)

Xu, Xing; Wan, Zhifeng; Wang, Xianqing; Sun, Yuefeng; Xia, Bin

2016-12-01

Marine heat flow is of great significance for the formation and occurrence of seabed oil, gas and gas hydrate resources. Geothermal gradient is an important parameter in determining the thickness of the hydrate stability zone. The northern slope of the South China Sea is rich in gas hydrate resources. Several borehole drilling attempts were successful in finding hydrates in the Shenhu area, while others were not. The failures demand further study on the distribution regularities of heat flow and its controlling effects on hydrate occurrence. In this study, forty-eight heat flow measurements are analyzed in the Shenhu gas hydrate drilling area, located in the northern South China Sea, together with their relationship to topography, sedimentary environment and tectonic setting. Canyons are well developed in the study area, caused mainly by the development of faults, faster sediment supply and slumping of the Pearl River Estuary since the late Miocene in the northern South China Sea. The heat flow values in grooves, occurring always in fault zones, are higher than those of ridges. Additionally, the heat flow values gradually increase from the inner fan, to the middle fan, to the external fan subfacies. The locations with low heat flow such as ridges, locations away from faults and the middle fan subfacies, are more conducive to gas hydrate occurrence.

3D instantaneous dynamics modeling of present-day Aegean subduction

Science.gov (United States)

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

2017-04-01

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

Influence of the May Southern annular mode on the South China Sea summer monsoon

Science.gov (United States)

Liu, Ting; Li, Jianping; Li, YanJie; Zhao, Sen; Zheng, Fei; Zheng, Jiayu; Yao, Zhixiong

2017-07-01

The possible impact of the May Southern Hemisphere (SH) annular mode (SAM) on the following South China Sea (SCS) summer monsoon (SCSSM) is examined. A close inverse relationship between the two is revealed in the observations. The simultaneous South Pacific dipole (SPD), a dipole-like sea surface temperature anomaly pattern in the South Pacific, acts as the "oceanic bridge" to preserve the May SAM signal and prolong it into June-September. Observational evidence and numerical simulations both demonstrate that the SPD communicates its large thermal inertia signal to the atmosphere, regulating the Southern Pacific Subtropical Jet (SPSJ) variability over eastern Australia. Corresponding to the adjustment of circulation associated with the SPSJ is a prominent tripolar cross-Pacific teleconnection pattern stretching from the SH middle-high latitudes into the NH East Asia coastal region, referred to as the South-North Pacific (SNP) teleconnection pattern. Wave ray tracing analysis manifests that the SNP acts as the "atmospheric bridge" to propagate the related wave energy across the equator and into the Maritime Continent and SCS monsoon region, modulating the vertical motion and middle-lower tropospheric flows, and favoring the out-of-phase variation of the SCSSM. Therefore, the "coupled oceanic-atmospheric bridge" process and the related Rossby wave energy transmission are possible mechanisms for the significant influence of the May SAM on the variability of the following SCSSM. Therefore, the May SAM provides a fresh insight into the prediction of the SCSSM from the perspective of the SH high latitudes.

A balanced Kalman filter ocean data assimilation system with application to the South Australian Sea

Science.gov (United States)

Li, Yi; Toumi, Ralf

2017-08-01

In this paper, an Ensemble Kalman Filter (EnKF) based regional ocean data assimilation system has been developed and applied to the South Australian Sea. This system consists of the data assimilation algorithm provided by the NCAR Data Assimilation Research Testbed (DART) and the Regional Ocean Modelling System (ROMS). We describe the first implementation of the physical balance operator (temperature-salinity, hydrostatic and geostrophic balance) to DART, to reduce the spurious waves which may be introduced during the data assimilation process. The effect of the balance operator is validated in both an idealised shallow water model and the ROMS model real case study. In the shallow water model, the geostrophic balance operator eliminates spurious ageostrophic waves and produces a better sea surface height (SSH) and velocity analysis and forecast. Its impact increases as the sea surface height and wind stress increase. In the real case, satellite-observed sea surface temperature (SST) and SSH are assimilated in the South Australian Sea with 50 ensembles using the Ensemble Adjustment Kalman Filter (EAKF). Assimilating SSH and SST enhances the estimation of SSH and SST in the entire domain, respectively. Assimilation with the balance operator produces a more realistic simulation of surface currents and subsurface temperature profile. The best improvement is obtained when only SSH is assimilated with the balance operator. A case study with a storm suggests that the benefit of the balance operator is of particular importance under high wind stress conditions. Implementing the balance operator could be a general benefit to ocean data assimilation systems.

Caspian Sea level changes during the last millennium: historical and geological evidences from the south Caspian Sea

Science.gov (United States)

Naderi Beni, A.; Lahijani, H.; Mousavi Harami, R.; Arpe, K.; Leroy, S. A. G.; Marriner, N.; Berberian, M.; Andrieu-Ponel, V.; Djamali, M.; Mahboubi, A.

2013-03-01

Historical literature may constitute a valuable source of information to reconstruct sea level changes. Here, historical documents and geological records have been combined to reconstruct Caspian sea-level (CSL) changes during the last millennium. In addition to a literature survey, new data from two short sediment cores were obtained from the south-eastern Caspian coast to identify coastal change driven by water-level changes. Two articulated bivalve shells from the marine facies were radiocarbon dated and calibrated to establish a chronology and to compare them with historical findings. The overall results indicate a high-stand during the Little Ice Age, up to -19 m, with a -28 m low-stand during the Medieval Climate Anomaly, while presently the CSL stands at -26.5 m. A comparison of the CSL curve with other lake systems and proxy records suggests that the main sea-level oscillations are essentially paced by solar irradiance. Although the major controller of the long-term CSL changes is driven by climatological factors, the seismicity of the basin could create locally changes in base level. These local base-level changes should be considered in any CSL reconstruction.

Caspian sea-level changes during the last millennium: historical and geological evidence from the south Caspian Sea

Science.gov (United States)

Naderi Beni, A.; Lahijani, H.; Mousavi Harami, R.; Arpe, K.; Leroy, S. A. G.; Marriner, N.; Berberian, M.; Andrieu-Ponel, V.; Djamali, M.; Mahboubi, A.; Reimer, P. J.

2013-07-01

Historical literature may constitute a valuable source of information to reconstruct sea-level changes. Here, historical documents and geological records have been combined to reconstruct Caspian sea-level (CSL) changes during the last millennium. In addition to a comprehensive literature review, new data from two short sediment cores were obtained from the south-eastern Caspian coast to identify coastal change driven by water-level changes and to compare the results with other geological and historical findings. The overall results indicate a high-stand during the Little Ice Age, up to -21 m (and extra rises due to manmade river avulsion), with a -28 m low-stand during the Medieval Climate Anomaly, while presently the CSL stands at -26.5 m. A comparison of the CSL curve with other lake systems and proxy records suggests that the main sea-level oscillations are essentially paced by solar irradiance. Although the major controller of the long-term CSL changes is driven by climatological factors, the seismicity of the basin creates local changes in base level. These local base-level changes should be considered in any CSL reconstruction.

Using simulations to forecast homeowner response to sea level rise in South Florida: Will they stay or will they go?

Science.gov (United States)

Treuer, G.

2017-12-01

Sea level rise threatens coastal communities around the world, including South Florida which may be the most financially vulnerable region in the world. Proactive investments in sea level rise adaptive flood protections could reduce South Florida's financial vulnerability. However, it is unclear if local governments and homeowners will be willing to make those investments before it is too late. Our research explores this issue by reporting the results of a novel online simulation that accelerates 348 South Florida homeowners thirty-five years into the future so that they can `live' the effects of sea level rise. The results contain a mix of optimism and caution for the prospects of future adaptation. On the positive side over 75% of participants indicated a willingness to support bond issues to pay for adaptation, even as the costs of the measures and effects of sea level rise increased over the years. Likewise, we find little evidence that politically conservative residents who normally have more skeptical views about climate change would be any less inclined to support adaptation, or only look to information sources that downplay the threat. On the negative side, homeowner interest in moving out of the region increases steadily over time as the sea level rises. This is driven by an increase in worry associated with viewing more information within the simulation.

ANALYSIS OF LOW-FREQUENCY OSCILLATIONS FOR THE SOUTH CHINA SEA SUMMER MONSOON IN 1998

Institute of Scientific and Technical Information of China (English)

徐国强; 朱乾根

2003-01-01

With NCEP/NCAR reanalysis daily data and SST for 1998, the paper investigates the features of summer monsoon low-frequency oscillation (LFO) over the South China Sea (SCS). Results show that SCS summer monsoon onset is enhanced because of its LFO. Low-frequency (LF) low-level convergence (divergence) region of SCS is in the LF positive (negative) rainfall area. LFO of the SCS region migrates from south to north in the meridian and from west to east in zonal direction. LF divergence of SCS is vertically compensating to each other between high and low level.

Disentangling sea-surface temperature and anthropogenic aerosol influences on recent trends in South Asian monsoon rainfall

Science.gov (United States)

Patil, Nitin; Venkataraman, Chandra; Muduchuru, Kaushik; Ghosh, Subimal; Mondal, Arpita

2018-05-01

Recent studies point to combined effects of changes in regional land-use, anthropogenic aerosol forcing and sea surface temperature (SST) gradient on declining trends in the South Asian monsoon (SAM). This study attempted disentangling the effects produced by changes in SST gradient from those by aerosol levels in an atmospheric general circulation model. Two pairs of transient ensemble simulations were made, for a 40-year period from 1971 to 2010, with evolving versus climatological SSTs and with anthropogenic aerosol emissions fixed at 1971 versus 2010, in each case with evolution of the other forcing element, as well as GHGs. Evolving SST was linked to a widespread feedback on increased surface temperature, reduced land-sea thermal contrast and a weakened Hadley circulation, with weakening of cross-equatorial transport of moisture transport towards South Asia. Increases in anthropogenic aerosol levels (1971 versus 2010), led to an intensification of drying in the peninsular Indian region, through several regional pathways. Aerosol forcing induced north-south asymmetries in temperature and sea-level pressure response, and a cyclonic circulation in the Bay of Bengal, leading to an easterly flow, which opposes the monsoon flow, suppressing moisture transport over peninsular India. Further, aerosol induced decreases in convection, vertically integrated moisture flux convergence, evaporation flux and cloud fraction, in the peninsular region, were spatially congruent with reduced convective and stratiform rainfall. Overall, evolution of SST acted through a weakening of cross-equatorial moisture flow, while increases in aerosol levels acted through suppression of Arabian Sea moisture transport, as well as, of convection and vertical moisture transport, to influence the suppression of SAM rainfall.

Island dynamics and Minoan expansion in the Aegean: the Kythera Island Project

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Cyprian Broodbank

1999-11-01

Full Text Available In recent years archaeologists have become increasingly interested in the investigation of island societies. At a global level, discoveries in the Pacific, Caribbean, Mediterranean and elsewhere have greatly improved our understanding of the antiquity and dynamics of island life. Now archaeologists at the Institute, together with other colleagues, have embarked on a long-term interdisciplinary study of the island of Kythera in the Aegean.

Microseismicity in the southeastern Aegean using data of the temporary EGELADOS network

Science.gov (United States)

Brüstle, A.; Küperkoch, L.; Meier, T.; Friederich, W.; Egelados Working Group

2009-04-01

The temporary broadband EGELADOS network covered the entire Hellenic Subduction Zone from October 2005 to April 2007. Seismic events are detected and identified by an STA/LTA-trigger and a grid-search algorithm, where relative travel times of pre-defined masterevents are compared to observed differential trigger times. Because of the high seismicity, we focus on the south-eastern part of the Hellenic Subduction Zone including the forearc around Rhodes, Karpathos and Kassos and the volcanic arc around Nisyros. In addition, the considered region covers the transition zone from the Aegean to the Anatolian microplates at the west coast of Turkey. For this region more than 1800 of the 2646 events, triggered during the first 6 months of the experiment, were identified as local earthquakes and localised. The other triggers represent earthquakes outside the working region, multiply triggered events, teleseismic events or noise, respectively. Microseismicity down to a magnitude of about ML 1.8 is detected completely. In regions with an increased station density, microseismicity may be observed completely down to magnitudes of ML 1. High shallow microseismicity is observed in the forearc with clusters southeast of Crete (Ptolemy trench), south of Karpathos and southwest of Amorgos within the volcanic arc. A continuous seismically active zone strikes along the EW trending rift of the Gulf of Gökova to western Kos and changes its direction to NS by crossing the volcanic island Nisyros and extruding into the forearc near Kassos. Intermediate depth seismicity of the subducting slab is located in the volcanic arc between Astypalea and Tilos. The strong attenuation of the S-waves of intermediate depth events points to low Q in the mantle wedge above the subducting African lithosphere. In contrast, S-waves propagating within the slab from the source to the stations in the forearc are much less attenuated.

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

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G. A. Papadopoulos

2006-01-01

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

On the finding of the Indo-Pacific fish Scomberomorus commerson in Rhodes (Greece

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M. CORSINI-FOKA

2008-05-01

Full Text Available The occurrence of the Indo-Pacific fish Scomberomorus commerson was observed for the first time in the Hellenic waters of the SE Aegean Sea during the spring 2008. The record may represent a first indication of a population expansion of this alien species along the southern coasts of the Aegean Sea.

Holocene megathermal abrupt environmental changes derived from {sup 14}C dating of a coral reef at Leizhou Peninsula, South China Sea

Energy Technology Data Exchange (ETDEWEB)

Shen Chengde; Yi Weixi E-mail: cdshen@gig.ac.cn; Yu Kefu; Sun Yanmin; Liu Tungsheng; Beer, J.; Hajdas, I.; Bonani, G

2004-08-01

A depth profile of a Goniopora coral reef at Leizhou Peninsula, South China Sea, was radiocarbon dated using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The time of formation, during 6600-7400 cal BP, can be divided into nine stages, each terminated by abrupt growth cessation of Goniopora and appearance of Ostrea shells. The results show that, during the Holocene megathermal (8.2-3.3 ka BP), large climatic changes have occurred in the South China Sea area.

THE SOUTHERN AEGEAN SYSTEM

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Ina Berg

2015-08-01

Full Text Available Although world-systems theory was originally formulated with our modern economic system in mind (Wallerstein 1974, it was not long before archaeologists began to apply it to ancient societies. Archaeologists and world-system theorists alike both argued that Wallerstein had disregarded evidence of interconnected, hierarchical systems in prehistoric times (Schneider 1977; Chase-Dunn & Hall 1991, 1997; Kardulias 1999a. Pailes and Whitecotton (1979 were among the first to modify world-systems theory for use in pre-capitalist settings. Since then many archaeologists have looked at data and regions with a world-systems perspective in mind (e.g. Champion 1989; Bilde et al. 1993; Rowlands & Larsen 1987; Kardulias 1999a. Some have attempted to map Wallerstein's theory directly onto prehistory (Kohl 1979; Whitecotton & Pailes 1986; Ekholm & Friedman 1982. Others have found the world systems model heuristically useful but lacking the analytical power needed for their prehistoric cases (Blanton et al. 1981; Upham 1982; Plog 1983; Alcock 1993. Building on the assumption that ancient societies were not qualitatively, but only quantitatively, different from modern capitalist ones (Schneider 1977; Sherratt & Sherratt 1991, this study applies world systems theory to the Southern Aegean during the Middle and Late Bronze Age (ca. 2000-1550 BC.

Sea level rise, surface warming, and the weakened buffering ability of South China Sea to strong typhoons in recent decades.

Science.gov (United States)

Sun, Jingru; Oey, Leo; Xu, F-H; Lin, Y-C

2017-08-07

Each year, a number of typhoons in the western North Pacific pass through the Luzon Strait into South China Sea (SCS). Although the storms remain above a warm open sea, the majority of them weaken due to atmospheric and oceanic environments unfavorable for typhoon intensification in SCS, which therefore serves as a natural buffer that shields the surrounding coasts from potentially more powerful storms. This study examines how this buffer has changed over inter-decadal and longer time scales. We show that the buffer weakens (i.e. greater potential for more powerful typhoons) in negative Pacific Decadal Oscillation (PDO) years, as well as with sea-level-rise and surface warming, caused primarily by the deepening of the ocean's 26 °C isotherm Z 26 . A new Intensity Change Index is proposed to describe the typhoon intensity change as a function of Z 26 and other environmental variables. In SCS, the new index accounts for as high as 75% of the total variance of typhoon intensity change.

Long-term changes of South China Sea surface temperatures in winter and summer

Science.gov (United States)

Park, Young-Gyu; Choi, Ara

2017-07-01

Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

Radioecological monitoring of the Black Sea basin following the Chernobyl NPP accident

International Nuclear Information System (INIS)

Kulebakina, L.G.; Polikarpov, G.G.

1991-01-01

A monitoring programme was drawn up to study the radioecological situation of the Black Sea basin following the Chernobyl NPP accident, with studies being carried out from May 1986 onwards to determine the levels of radioactive contamination in various parts of the Black Sea, the Sea of Azov and the Aegean Sea, including the estuaries of major rivers (Dnieper, Danube, Dniester and Don) and shelf areas of the Black Sea and the Sea of Azov. The work focused on long-lived radionuclides ( 90 Sr and 137 Cs), with the migration dynamics of these radionuclides in the aquatic environment, bed sediments and aquatic biota (including plants, molluscs, crustacea and fish) being studied. We compared the behaviour of radionuclides in the aquatic environment of the Dnieper reservoirs following the Chernobyl accident (our data) with the behaviour of radionuclides in lakes in the Urals following the Kyshtym accident (published data). As in the case of the lakes in the Urals, the Dnieper waters contain substantial concentrations of 90 Sr as a result of the Chernobyl accident, and 90 Sr therefore enters the Black Sea with the Dnieper waters. The paper compares the contribution of the Chernobyl accident to radioactive contamination of the Black Sea with that of global fallout. (author)

Occurrence and distribution of conventional and new classes of per- and polyfluoroalkyl substances (PFASs) in the South China Sea.

Science.gov (United States)

Kwok, Karen Y; Wang, Xin-Hong; Ya, Miaolei; Li, Yongyu; Zhang, Xiao-Hua; Yamashita, Nobuyoshi; Lam, James C W; Lam, Paul K S

2015-03-21

Concentrations of 23 per- and polyfluoroalkyl substances (PFASs), including new classes of PFASs, in seawater samples were investigated for their occurrence and the interaction of the ocean currents with the distribution of PFASs in the South China Sea. This study revealed that socio-economic development was associated with the PFAS contamination in coastal regions of South China. Significant correlations between concentration of total PFASs with gross domestic product (GDP) per capita and population density were found in the areas, suggesting that the influence of intense human activities in these areas may have resulted in higher PFAS contamination to the adjacent environment. Di-substituted polyfluoroalkyl phosphate (diPAP), one of the potential replacements for PFASs, was only detected in the heavily developed region, namely Pearl River Delta (PRD). Total PFAS concentrations, ranging from 195 to 4925 pg/L, were detected at 51 sampling stations of the South China Sea. The results also confirmed that PFAS contamination in the South China Sea is strongly affected by the ocean currents. In comparison to perfluoroactane sulfonate (PFOS) concentrations measured nine years ago at the same locations, the concentrations in this study were found to be two times higher. This indicated that the use and production of perfluoroalkyl sulfonates (PFSAs) has been continuing in the region. Copyright © 2014 Elsevier B.V. All rights reserved.

THE IMPACT OF ORGANIZATIONAL STRUCTURE ON GLASS CEILING: AEGEAN REGION AGENCIES IN TURKEY

OpenAIRE

İNEL, Merve; GARAYEV, Vener; BAKAY, Aziz

2014-01-01

This study examined the relationship between organizationalstructure (mechanistic/organic) and glass ceiling, the concept known asnegative discrimination against women in workplace. The data collected fromrandomly selected 81 organizations in Aegean Region of Turkey was analyzedthrough hierarchical stepwise multiple regression. The results of the finalregression model suggest that glass ceiling is not dependent on organizationalstructure, while the control variable gender has a negative relat...

New species of the giant deep-sea isopod genus Bathynomus (Crustacea, Isopoda, Cirolanidae) from Hainan Island, South China Sea.

Science.gov (United States)

Kou, Qi; Chen, Jun; Li, Xinzheng; He, Lisheng; Wang, Yong

2017-07-01

Several specimens of the giant deep-sea isopod genus Bathynomus were collected by a deep-sea lander at a depth of 898 m near Hainan Island in the northern South China Sea. After careful examination, this material and the specimens collected from the Gulf of Aden, north-western Indian Ocean, previously reported as Bathynomus sp., were identified to be the same as a new species to the genus. Bathynomus jamesi sp. nov. can be distinguished from the congeners by: the distal margin of pleotelson with 11 or 13 short straight spines and central spine not bifid; uropodal endopod and exopod with distolateral corner slightly pronounced; clypeus with lateral margins concave; and antennal flagellum extending when extended posteriorly reaches the pereonite 3. In addition, Bathynomus jamesi sp. nov. is also supported by molecular analyses based on mitochondrial COI and 16S rRNA gene sequences. The distribution range of the new species includes the western Pacific and north-western Indian Ocean. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Assessment of the Joint Development Potential of Wave and Wind Energy in the South China Sea

Directory of Open Access Journals (Sweden)

Yong Wan

2018-02-01

Full Text Available The South China Sea is a major shipping hub between the West Pacific and Indian Oceans. In this region, the demand for energy is enormous, both for residents’ daily lives and for economic development. Wave energy and wind energy are two major clean and low-cost ocean sources of renewable energy. The reasonable development and utilization of these energy sources can provide a stable energy supply for coastal cities and remote islands of China. Before wave energy and wind energy development, however, we must assess the potential of each of these sources. Based on high-resolution and high-accuracy wave field data and wind field data obtained by ERA-Interim reanalysis for the recent 38-year period from 1979–2016, the joint development potential of wave energy and wind energy was assessed in detail for offshore and nearshore areas in the South China Sea. Based on potential installed capacity, the results revealed three promising areas for the joint development of nearshore wave energy and wind energy, including the Taiwan Strait, Luzon Strait and the sea southeast of the Indo-China Peninsula. For these three dominant areas (key stations, the directionality of wave energy and wind energy propagation were good in various seasons; the dominant wave conditions and the dominant wind conditions were the same, which is advantageous for the joint development of wave and wind energy. Existing well-known wave energy converters (WECs are not suitable for wave energy development in the areas of interest. Therefore, we must consider the distributions of wave conditions and develop more suitable WECs for these areas. The economic and environmental benefits of the joint development of wave and wind energy are high in these promising areas. The results described in this paper can provide references for the joint development of wave and wind energy in the South China Sea.

Paleohydrology reconstruction and Holocene climate variability in the South Adriatic Sea

Directory of Open Access Journals (Sweden)

G. Siani

2013-02-01

Full Text Available Holocene paleohydrology reconstruction is derived combining planktonic and benthic stable oxygen and carbon isotopes, sea surface temperatures (SSTs and oxygen isotope composition of seawater (δ18Ow from a high sedimentation core collected in the South Adriatic Sea (SAS. Core chronology is based on 10 AMS 14C measures on planktonic foraminifera and tephra layers. Results reveal two contrasted paleohydrological periods that reflect (i a marked lowering of δ18Ow/salinity during the early to mid-Holocene (11.5 ka to 6.3 ka, including the two-step sapropel S1 deposition, followed during the mid- to upper Holocene by (ii a prevailing period of increased salinity and enhanced arid conditions in the South Adriatic Basin. Superimposed on these trends, short-term centennial-scale hydrological events punctuated the Holocene period in the SAS. During the early to mid-Holocene, two main SST coolings together with prominent δ18Ow/salinity lowering delineate the sapropel S1 interruption and the post-sapropel phase between 7.3 to 6.3 ka. After 6 ka, centennial-scale δ18Ow and G. bulloides δ13C lowering, mostly centered between 3 to 0.6 ka, reflect short-term hydrological changes related to more intensive runoff of the Po and/or Apennine rivers. These short-term events, even of lesser amplitude compared to the early to mid-Holocene period, may have induced a lowering of sea surface density and consequently reduced and/or inhibited the formation of deep bottom waters in the SAS. Comparison of the emerging centennial- to millennial-scale hydrological record with previous climatic records from the central Mediterranean area and north of the Alps reveal possible synchronicities (within the radiocarbon-dating uncertainty between phases of lower salinity in the SAS and periods of wetter climatic conditions around the north-central Adriatic Sea. Finally, wavelet analyses provide new clues about the potential origin of climate variability in the SAS, confirming

CAN INTERNATIONAL LAW MAKE A DIFFERENCE UNCLOS AND THE SOUTH CHINA SEA

Science.gov (United States)

2017-03-20

insignificant to a country that is hedging its bets and its control to become a regional power house. 15 Unfortunately for China, the PCA’s decision...published by China’s think tank, the National Institute for South China Sea Studies, that warns the US that its freedom of navigation patrols in the...Bloomberg, “US Naval Patrols Threaten Sovereignty, China Think Tank Warns,” Stars and Stripes 25 November 2016 https://www.stripes.com/news

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.

Nutrient Dynamics in the Northern South China Sea Shelf-sea (NoSoCS)

Science.gov (United States)

Wong, G. T.; Guo, X.

2011-12-01

The Northern South China Sea Shelf-sea (NoSoCS) is situated in the sub-tropics along the southern Chinese coast between the southern end of the Taiwan Strait and the Hainan Island. Samples were collected in four cross-shelf transects in summer, 2010 and two cross-shelf transects in winter, 2011 in this Shelf-sea. The shelf may be sub-divided into the inner shelf (1 μM in NO3- and >0.1 μM in soluble reactive phosphate) stretched across the shelf at least to the middle shelf. Thus, vertical mixing, even to relatively shallow depths, on the shelf may supply nutrients to and play a critical role in determining the primary production in the mixed layer. At least three such processes were observed. Through the year, internal waves of various strengths generated at the Luzon Strait propagated westward along the bottom of the mixed layer and dissipated along the middle and outer shelf. The effects of these waves were especially conspicuous north of the Dongsha Atoll and their action enhances vertical mixing. In the summer, upwelling occurred in the inner/middle shelf off Dongshan in response to the along shore southwest monsoon and the topographic forcing by the ridge extending offshore from Dongshan to the Taiwan Bank. In the winter, surface cooling and the strong northeast monsoon led to complete overturn in the shelf. The maximum density, reaching 24.6, in the surface waters was found offshore in the inner and middle shelf. This density was equivalent to the density of the water at >100 m offshore. As a result, this dense water also appeared as a layer of bottom water that extended across the shelf to the shelf edge.

Mitochondrial control region haplotypes of the South American sea lion Otaria flavescens (Shaw, 1800).

Science.gov (United States)

Artico, L O; Bianchini, A; Grubel, K S; Monteiro, D S; Estima, S C; Oliveira, L R de; Bonatto, S L; Marins, L F

2010-09-01

The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande), both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop) was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7), with OFA1 being the most frequent (47.54%). Nucleotide diversity was moderate (π = 0.62%) and haplotype diversity was relatively low (67%). Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.

Formation of early-middle Miocene red beds in the South China Sea: element geochemistry and mineralogy analysis

Science.gov (United States)

Lyu, X.; Liu, Z.

2017-12-01

The formation of oceanic red beds that usually present oxic and oligotrophic conditions with low sedimentation rate has been used to trace depositional paleoenvironment and paleoclimate change. Red beds overlying oceanic basalts were drilled at two adjacent Sites U1433 and U1434 of IODP Expedition 349 in the Southwest Subbasin of the South China Sea. The occurrence of early-middle Miocene red beds may indicate that at that time there was oxic and quiet marine environment in the deep South China Sea. To understand their formation of red-color, local depositional condition, and potential paleoceanographic significance, major elements (XRF), trace and rare earth elements (ICP-MS), Fe chemical speciation (modified sequential iron extraction procedure), and Fe oxic minerals (CBD and DRS) were analyzed. Geochemical and mineralogical data reveal that hematite and goethite are responsible for the reddish color and red beds were deposited under highly oxic, oligotrophic conditions with a little later hydrothermal influence in the South China Sea. Our results indicate that: (1) after treatment using the CBD procedure, the red samples presented a change in color to greenish, showing the iron oxides being responsible for the sediment color; (2) enriched Mn, depleted U, S enrichment factors, and negative Ce anomaly show that the water mass was pre-oxidized before transported to the study location; (3) low primary productivity was inferred from the lower P, Ba enrichment factors in red beds compared to non-red beds; (4) the excess Mo influx at the bottom may come from the later hydrothermal input; (5) the diverse Ca enrichment factors and correlations between Fe and Al suggest different allogenic sources for red beds at our two sites. We conclude that the red beds at Sites U1433 and U1434 despite their diverse sources both developed in externally oxidized water mass and low primary productivity conditions, and partially altered by hydrothermal fluids after their pelagic

Territorial disputes simmer in areas of South China Sea

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that China's award of an exploration cooperation contact in the Nansha area of the South China Sea has revived territorial disputes in the area centering ton the Spratly and Paracel islands. The key dispute is between China and Viet Nam, which earlier engaged in military action over ownership of the islands, believed to have world class potential for hydrocarbon discoveries. Those two nations, as well as Brunei, Malaysia, Philippines, and Taiwan, lay claim to overlapping boundaries of the Spratly Islands. Separately, China and Viet Nam dispute territorial claims in the Paracels. Tensions continue to mount, and regional governments are trying to negotiate compromises to avoid a repeat of warfare

Role of atmospheric heating over the South China Sea and western Pacific regions in modulating Asian summer climate under the global warming background

Science.gov (United States)

He, Bian; Yang, Song; Li, Zhenning

2016-05-01

The response of monsoon precipitation to global warming, which is one of the most significant climate change signals at the earth's surface, exhibits very distinct regional features, especially over the South China Sea (SCS) and adjacent regions in boreal summer. To understand the possible atmospheric dynamics in these specific regions under the global warming background, changes in atmospheric heating and their possible influences on Asian summer climate are investigated by both observational diagnosis and numerical simulations. Results indicate that heating in the middle troposphere has intensified in the SCS and western Pacific regions in boreal summer, accompanied by increased precipitation, cloud cover, and lower-tropospheric convergence and decreased sea level pressure. Sensitivity experiments show that middle and upper tropospheric heating causes an east-west feedback pattern between SCS and western Pacific and continental South Asia, which strengthens the South Asian High in the upper troposphere and moist convergence in the lower troposphere, consequently forcing a descending motion and adiabatic warming over continental South Asia. When air-sea interaction is considered, the simulation results are overall more similar to observations, and in particular the bias of precipitation over the Indian Ocean simulated by AGCMs has been reduced. The result highlights the important role of air-sea interaction in understanding the changes in Asian climate.

Sediment compaction and pore pressure prediction in deepwater basin of the South China Sea: Estimation from ODP and IODP drilling well data

Science.gov (United States)

Xie, Yangbing; Wu, Tuoyu; Sun, Jin; Zhang, Hanyu; Wang, Jiliang; Gao, Jinwei; Chen, Chuanxu

2018-02-01

Overpressure in deepwater basins not only causes serious soft sediment deformation, but also significantly affects the safety of drilling operations. Therefore, prediction of overpressure in sediments has become an important task in deepwater oil exploration and development. In this study, we analyze the drilling data from ODP Leg 184 Sites 1144, 1146, and 1148, and IODP Leg 349 Sites U1431, U1432, U1433, and U1435 to study the sediment compaction and controls in the northern South China Sea. Sedimentation rate, sediment content, distribution area, and buried depth are the factors that influence sediment compaction in the deepwater basin of the South China Sea. Among these factors, the sediment content is the most important. The fitted normal compacted coefficients and mudline porosity for an interval of 50 m shows disciplinary variation versus depth. The pore pressure predicted from different fitted results shows varying overpressure situations. The normal compaction trend from Site 1144 reflects the porosity variation trend in stable deposition basins in the northern South China Sea. The predicted pore pressure shows overpressure at Site 1144, which is attributed to compaction disequilibrium. Nevertheless, the mixed lithology column may influence the predicted over-pressure at Site 1148, which is responsible for the confusing result. Above all, we find that sediment compaction should serve as a proxy for pore pressure in the deepwater basin of the South China Sea.

77 FR 28305 - Temporary Rule To Delay Start Date of 2012-2013 South Atlantic Black Sea Bass Commercial Fishing...

Science.gov (United States)

2012-05-14

.... 120501426-2426-01] RIN 0648-BB98 Temporary Rule To Delay Start Date of 2012-2013 South Atlantic Black Sea... this temporary rule to delay the start date of the 2012-2013 fishing season for the commercial black... temporary rule delays the start date of the 2012-2013 commercial fishing season for black sea bass from June...

Planting Flags on the Tide: Sovereignty, Containment, and Conflict Resolution in the East and South China Seas

Directory of Open Access Journals (Sweden)

James DeShaw Rae

2014-06-01

Full Text Available The rise of China’s economic and military power is transforming global politics while U.S. strategic interests are re-balancing toward Asia. Meanwhile, tensions over maritime boundaries and island claims within the region are punctuated by police and military stand-offs in the East and South China Seas. This paper considers the discourse surrounding the dispute over sovereignty in the South China Sea. It also examines the roles international law, multilateralism, and traditional diplomacy play in the conflict, and how it serves as a test case for China’s future diplomacy and traditional norms of non-interference and a peaceful rise. Finally, the paper suggests pathways toward conflict resolution of the immediate disputes, including de-territorialized and de-nationalized ideas of possession when it applies to contested yet uninhabited maritime frontiers.

Why is the South Orkney Island shelf (the world's first high seas marine protected area) a carbon immobilization hotspot?

Science.gov (United States)

Barnes, David K A; Ireland, Louise; Hogg, Oliver T; Morley, Simon; Enderlein, Peter; Sands, Chester J

2016-03-01

The Southern Ocean archipelago, the South Orkney Islands (SOI), became the world's first entirely high seas marine protected area (MPA) in 2010. The SOI continental shelf (~44 000 km(2) ), was less than half covered by grounded ice sheet during glaciations, is biologically rich and a key area of both sea surface warming and sea-ice losses. Little was known of the carbon cycle there, but recent work showed it was a very important site of carbon immobilization (net annual carbon accumulation) by benthos, one of the few demonstrable negative feedbacks to climate change. Carbon immobilization by SOI bryozoans was higher, per species, unit area and ice-free day, than anywhere-else polar. Here, we investigate why carbon immobilization has been so high at SOI, and whether this is due to high density, longevity or high annual production in six study species of bryozoans (benthic suspension feeders). We compared benthic carbon immobilization across major regions around West Antarctica with sea-ice and primary production, from remotely sensed and directly sampled sources. Lowest carbon immobilization was at the northernmost study regions (South Georgia) and southernmost Amundsen Sea. However, data standardized for age and density showed that only SOI was anomalous (high). High immobilization at SOI was due to very high annual production of bryozoans (rather than high densities or longevity), which were 2x, 3x and 5x higher than on the Bellingshausen, South Georgia and Amundsen shelves, respectively. We found that carbon immobilization correlated to the duration (but not peak or integrated biomass) of phytoplankton blooms, both in directly sampled, local scale data and across regions using remote-sensed data. The long bloom at SOI seems to drive considerable carbon immobilization, but sea-ice losses across West Antarctica mean that significant carbon sinks and negative feedbacks to climate change could also develop in the Bellingshausen and Amundsen seas. © 2015 John Wiley

Evidence of high genetic connectivity for the longnose spurdog Squalus blainville in the Mediterranean Sea

Directory of Open Access Journals (Sweden)

V. KOUSTENI

2015-04-01

Full Text Available Squalus blainville is one of the least studied Mediterranean shark species. Despite being intensively fished in several locations, biological knowledge is limited and no genetic structure information is available. This is the first study to examine the genetic structure of S. blainville in the Mediterranean Sea. Considering the high dispersal potential inferred for other squalid sharks, the hypothesis of panmixia was tested based on a 585 bp fragment of the mitochondrial DNA cytochrome c oxidase subunit I gene from 107 individuals and six nuclear microsatellite loci from 577 individuals. Samples were collected across the Ionian, Aegean and Libyan Seas and off the Balearic Islands. Twenty three additional sequences of Mediterranean and South African origin were retrieved from GenBank and included in the mitochondrial DNA analysis. The overall haplotype diversity was high, in contrast to the low nucleotide diversity. Low and non-significant pairwise ΦST and FST values along with a Bayesian cluster analysis suggested high connectivity with subsequent genetic homogeneity among the populations studied, and thus a high dispersal potential for S. blainville similar to other squalids. The historical demography of the species was also assessed, revealing a pattern of population expansion since the middle Pleistocene. These findings could be considered in species-specific conservation plans, although sampling over a larger spatial scale and more genetic markers are required to fully elucidate the genetic structure and dispersal potential of S. blainville.

The Intertemporal Principle in International Judicial Practice and Its Implications for the South China Sea Dispute

NARCIS (Netherlands)

Ma, Xuechan

2016-01-01

The intertemporal problem demonstrated in the South China Sea dispute is whether UNCLOS supersedes the previous legal order governing the disputed areas during the pre-UNCLOS period. In order to solve this problem, this article will conduct a detailed investigation into relevant international

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.

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).

Continental Extensional Tectonics in the Basins and Ranges and Aegean Regions: A Review

Science.gov (United States)

Cemen, I.

2017-12-01

The Basins and Ranges of North America and the Aegean Region of Eastern Europe and Asia Minor have been long considered as the two best developed examples of continental extension. The two regions contain well-developed normal faults which were considered almost vertical in the 1950s and 1960s. By the mid 1980s, however, overwhelming field evidence emerged to conclude that the dip angle normal faults in the two regions may range from almost vertical to almost horizontal. This led to the discovery that high-grade metamorphic rocks could be brought to surface by the exhumation of mid-crustal rocks along major low-angle normal faults (detachment faults) which were previously either mapped as thrust faults or unconformity. Within the last three decades, our understanding of continental extensional tectonics in the Basins and Ranges and the Aegean Region have improved substantially based on fieldwork, geochemical analysis, analog and computer modeling, detailed radiometric age determinations and thermokinematic modelling. It is now widely accepted that a) Basin and Range extension is controlled by the movement along the San Andreas fault zone as the North American plate moved southeastward with respect to the northwestward movement of the Pacific plate; b) Aegean extension is controlled by subduction roll-back associated with the Hellenic subduction zone; and c) the two regions contain best examples of detachment faulting, extensional folding, and extensional basins. However, there are still many important questions of continental extensional tectonics in the two regions that remain poorly understood. These include determining a) precise amount and percentage of cumulative extension; b) role of strike-slip faulting in the extensional processes; c) exhumation history along detachment surfaces using multimethod geochronology; d) geometry and nature of extensional features in the middle and lower crust; e) the nature of upper mantle and asthenospheric flow; f) evolutions

Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

Science.gov (United States)

Gao, Cheng-Hai; Wang, Yi-Fei; Li, Shen; Qian, Pei-Yuan; Qi, Shu-Hua

2011-01-01

Five zoanthoxanthin alkaloids (1–5) and four sesquiterpenes (6–9) were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2), 8-hydroxy-6β-methoxy-14- oxooplop-6,12-olide (6) and 3β-methoxyguaian-10(14)-en-2β-ol (7) were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae. PMID:22163197

A new species of the genus Linuparus White, from the South China Sea (Crustacea Decapoda)

NARCIS (Netherlands)

Bruce, A.J.

1965-01-01

The palinurid genus Linuparus White, 1847, has been represented by a single recent species, Linuparus trigonus (Von Siebold). The trawl survey of the northern shelf region of the South China Sea at present being carried out by the R.V. "Cape St. Mary" of the Fisheries Research Station, Hong Kong,

Detection of Total and Pathogenic Vibrio parahaemolyticus in Shellfish Growing along the South Yellow Sea and the East China Sea.

Science.gov (United States)

Han, Feng; Gu, Run-Run; Shen, Xiao-Sheng; Chen, Yuan-Ge; Tian, Liang-Liang; Zhou, Wei-Feng; Cai, You-Qiong

2017-10-17

This study was conducted to monitor the densities of total and pathogenic Vibrio parahaemolyticus in 300 samples of nine shellfish species harvested from the coasts of the South Yellow Sea and the East China Sea (N 23° to 34°, E 116° to 124°), People's Republic of China, between May and October 2015. Total V. parahaemolyticus densities were measured, and V. parahaemolyticus isolates were biochemically identified with probes for the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh). We found that 202 of the 300 samples were positive for V. parahaemolyticus from all the sites: 58 of the 100 samples from the Fujian province, 71 of the 100 samples from the Zhejiang province, and 73 of the 100 samples from the Jiangsu province. In most (170) of the 300 samples, V. parahaemolyticus densities were 0.3 to 10 most probable number (MPN)/g; five lots exceeded 110 MPN/g, and two lots were estimated at 110 MPN/g. Among the 202 V. parahaemolyticus strains, only one was trh positive. Densities of V. parahaemolyticus in these shellfish were temperature dependent, with highest densities in June and July. Among the nine mollusk species, V. parahaemolyticus was most abundant in the agemaki clam (Sinonovacula constricta). The highest and lowest V. parahaemolyticus prevalences were found in oriental cyclina (Cyclina sinensis, 93.8%) and mussels (Mytilus edulis, 28.1%), respectively. Overall, although V. parahaemolyticus is widely distributed in marine environments, the density of V. parahaemolyticus was low and the prevalence of the main virulence factor was very low in shellfish along the coasts of the South Yellow Sea and East China Sea, which is important from a public health perspective. Data presented here will be useful for correlational research and can be utilized for developing risk management plans that establish food safety guidelines for V. parahaemolyticus in Chinese shellfish.

Important aspects of Eastern Mediterranean large-scale variability revealed from data of three fixed observatories

Science.gov (United States)

Bensi, Manuel; Velaoras, Dimitris; Cardin, Vanessa; Perivoliotis, Leonidas; Pethiakis, George

2015-04-01

Long-term variations of temperature and salinity observed in the Adriatic and Aegean Seas seem to be regulated by larger-scale circulation modes of the Eastern Mediterranean (EMed) Sea, such as the recently discovered feedback mechanisms, namely the BiOS (Bimodal Oscillating System) and the internal thermohaline pump theories. These theories are the results of interpretation of many years' observations, highlighting possible interactions between two key regions of the EMed. Although repeated oceanographic cruises carried out in the past or planned for the future are a very useful tool for understanding the interaction between the two basins (e.g. alternating dense water formation, salt ingressions), recent long time-series of high frequency (up to 1h) sampling have added valuable information to the interpretation of internal mechanisms for both areas (i.e. mesoscale eddies, evolution of fast internal processes, etc.). During the last 10 years, three deep observatories were deployed and maintained in the Adriatic, Ionian, and Aegean Seas: they are respectively, the E2-M3A, the Pylos, and the E1-M3A. All are part of the largest European network of Fixed Point Open Ocean Observatories (FixO3, http://www.fixo3.eu/). Herein, from the analysis of temperature and salinity, and potential density time series collected at the three sites from the surface down to the intermediate and deep layers, we will discuss the almost perfect anti-correlated behavior between the Adriatic and the Aegean Seas. Our data, collected almost continuously since 2006, reveal that these observatories well represent the thermohaline variability of their own areas. Interestingly, temperature and salinity in the intermediate layer suddenly increased in the South Adriatic from the end of 2011, exactly when they started decreasing in the Aegean Sea. Moreover, Pylos data used together with additional ones (e.g. Absolute dynamic topography, temperature and salinity data from other platforms) collected

Fluvial Responses to Holocene sea Level Variations Along the Macdonald River, New South Wales, Australia

Science.gov (United States)

Rustomji, P.; Chappell, J.; Olley, J.

2003-12-01

The Macdonald River drains the rugged eastern flanks of Australia's Great Dividing Range. It has a catchment area of 2000km2, restricted alluvial lowlands confined by bedrock interfluves and flows into the Hawkesbury River, a larger estuarine valley. The Macdonald valley is presently tidal for 14km from the Hawkesbury. At about 8000 year before present (BP), rising sea level invaded the Macdonald Valley for at least 35km upstream of the Hawkesbury River. Rapid aggradation occurred between 8000 and 6000 years BP and a sand bed river was established in the Macdonald Valley, its mouth prograding rapidly towards the Hawkesbury. Little is known about the character of the sand bed river during the +2 meter sea level highstand occurring between 5000 and 4000 BP. However, from 3000 to 1500 BP when sea level was consistently at +1 to +1.5m, major floodplain and levee-like structures, now virtually inactive, were established. The bed is inferred to have been elevated above its present day level and consequently intersected mean sea level (MSL) downstream of its present location. This is consistent with reported sea levels at +1 to +2m above present levels for the New South Wales coast at this time. From 1500 years BP, local sea level fell rapidly to its present level. Aggradation of the levee crests ceased and sedimentation along the valley became restricted to aggradation of an inset floodplain, within the pre-1500 BP deposits. The channel contracted and the sandy river bed incised. An equivalent and synchronous change in sedimentation style is observed along the Tuross River 400km south of the Macdonald, lending support to sea level variations being the factor driving this change. By 1850 AD, the bed dipped below MSL about 10km upstream of its inferred position prior to 1500 years BP. A series of large floods between 1949 and 1955 eroded significant volumes of sandy sediment from the Holocene deposits. The channel bed widened from between 25 and 50m width to ˜100m along

Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

DEFF Research Database (Denmark)

Chang, Rui; Rong, Zhu; Badger, Merete

2015-01-01

offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...... (SD) of 2.09 m/s (1.83 m/s) and correlation coefficient of R 0.75 (0.80). When the offshore winds (i.e., winds directed from land to sea) are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean...

Factors Affecting Purchase Intention of South East Asian (SEA Young Adults towards Global Smartphone Brands

Directory of Open Access Journals (Sweden)

Wahid Zahid

2016-06-01

Full Text Available The study aims to probe the effect of perceived price, perceived quality, brand awareness, and social influence on purchase intention of South East Asian (SEA Young Adults towards global smartphone brands. This explanatory research uses quantitative empirical data collected from 200 SEA Young Adults studying in one of the public universities in Malaysia. Stratified random sampling is used while ensuring fair representation of SEA countries, viz., Singapore, Malaysia, Philippines, Thailand, Indonesia, Vietnam, and Cambodia. Correlation and regression analysis were carried out using SPSS 20.0. The study resulted in the finding that social influence has the highest level of linear relationship and so is the most influential factor among four. The findings provide guidelines to global smartphone brands for developing value proposition and better promotion mix for smartphones promotion.

Realized niches explain spatial gradients in seasonal abundance of phytoplankton groups in the South China Sea

Science.gov (United States)

Xiao, Wupeng; Wang, Lei; Laws, Edward; Xie, Yuyuan; Chen, Jixin; Liu, Xin; Chen, Bingzhang; Huang, Bangqin

2018-03-01

A basic albeit elusive goal of ocean science is to predict the structure of biological communities from the multitude of environmental conditions they experience. Estimates of the realized niche-based traits (realized traits) of phytoplankton species or functional groups in temperate seas have shown that response traits can help reveal the mechanisms responsible for structuring phytoplankton communities, but such approaches have not been tested in tropical and subtropical marginal seas. Here, we used decadal-scale studies of pigment-based phytoplankton groups and environmental conditions in the South China Sea to test whether realized traits could explain the biogeographic patterns of phytoplankton variability. We estimated the mean and breadth of the phytoplankton realized niches based on responses of the group-specific phytoplankton composition to key environmental factors, and we showed that variations of major phytoplankton groups in this system can be explained by different adaptive trade-offs to constraints imposed by temperature, irradiance, and nutrient concentrations. Differences in the patterns of trade-offs clearly separated the dominant groups from one another and generated four sets of realized traits that mirrored the observed biogeographic distribution patterns. The phytoplankton realized niches and their associated traits that we characterized in the present study could help to predict responses of phytoplankton to changes in environmental conditions in the South China Sea and could be incorporated into global biogeochemical models to anticipate shifts in community structure under future climate scenarios.

First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

Science.gov (United States)

Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

2016-01-01

Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea.

Fission track analysis and evolution of mesozoic-paleozoic hydrocarbon resource-rocks headed in Northern Jiangsu-South Yellow sea basin

International Nuclear Information System (INIS)

Xu Hong; Cai Qianzhong; Sun Heqing; Guo Zhenxuan; Yan Guijing; Dai Jing; Liu Dongying

2008-01-01

Fission track data of different geologic epoches from Binhai salient, Yancheng sag, Haian sag, Baiju sag, Gaoyou sag, Hongze sag and Jinhu sag of northern Jiangsu basin and seismic data from Laoshan uplift in South Yellow Sea basin and evolution of Paleozoic hydrocarbon resource-rocks headed in the Northern Jiangsu-South Yellow Sea basin were studied. Results indicate that Binhai salient uplifted in 38-15 Ma, forming 'structure uplifting model', Paleozoic hydrocarbon resource-rocks have the appearance of 'different layers but identical mature, different layers but identical temperature' with Laoshan uplift. All sags have the characters of 'long time heating model', and sedimentations in Cenozoic were exploited by 2 km. Mesozoic-Paleozoic hydrocarbon resource- rocks of Laoshan uplift get ahead of 10 km. Structure evolution was compared with Binhai salient. According to the modeling results of secondary hydrocarbon generation, Mesozoic-Paleozoic hydrocarbon resource-rocks of Laoshan uplift have the good reservoir potentiality and probably become an important new window for sea oil and gas exploration. (authors)

The Effect of the South Asia Monsoon on the Wind Sea and Swell Patterns in the Arabian Sea

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Semedo, Alvaro

2015-04-01

Ocean surface gravity waves have a considerable impact on coastal and offshore infrastructures, and are determinant on ship design and routing. But waves also play an important role on the coastal dynamics and beach erosion, and modulate the exchanges of momentum, and mass and other scalars between the atmosphere and the ocean. A constant quantitative and qualitative knowledge of the wave patterns is therefore needed. There are two types of waves at the ocean surface: wind-sea and swell. Wind-sea waves are growing waves under the direct influence of local winds; as these waves propagate away from their generation area, or when their phase speed overcomes the local wind speed, they are called swell. Swell waves can propagate thousands of kilometers across entire ocean basins. The qualitative analysis of ocean surface waves has been the focus of several recent studies, from the wave climate to the air-sea interaction community. The reason for this interest lies mostly in the fact that waves have an impact on the lower atmosphere, and that the air-sea coupling is different depending on the wave regime. Waves modulate the exchange of momentum, heat, and mass across the air-sea interface, and this modulation is different and dependent on the prevalence of one type of waves: wind sea or swell. For fully developed seas the coupling between the ocean-surface and the overlaying atmosphere can be seen as quasi-perfect, in a sense that the momentum transfer and energy dissipation at the ocean surface are in equilibrium. This can only occur in special areas of the Ocean, either in marginal seas, with limited fetch, or in Open Ocean, in areas with strong and persistent wind speed with little or no variation in direction. One of these areas is the Arabian Sea, along the coasts of Somalia, Yemen and Oman. The wind climate in the Arabian sea is under the direct influence of the South Asia monsoon, where the wind blows steady from the northeast during the boreal winter, and

Isotopic composition and distribution of plutonium in northern South China Sea sediments revealed continuous release and transport of Pu from the Marshall Islands.

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Wu, Junwen; Zheng, Jian; Dai, Minhan; Huh, Chih-An; Chen, Weifang; Tagami, Keiko; Uchida, Shigeo

2014-03-18

The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios in sediments of the northern South China Sea and its adjacent Pearl River Estuary were determined to examine the spatial and temporal variations of Pu inputs. We clarified that Pu in the study area is sourced from a combination of global fallout and close-in fallout from the Pacific Proving Grounds in the Marshall Islands where above-ground nuclear weapons testing was carried out during the period of 1952-1958. The latter source dominated the Pu input in the 1950s, as evidenced by elevated (240)Pu/(239)Pu atom ratios (>0.30) in a dated sediment core. Even after the 1950s, the Pacific Proving Grounds was still a dominant Pu source due to continuous transport of remobilized Pu from the Marshall Islands, about 4500 km away, along the North Equatorial Current followed by the transport of the Kuroshio current and its extension into the South China Sea through the Luzon Strait. Using a simple two end-member mixing model, we have quantified the contributions of Pu from the Pacific Proving Grounds to the northern South China Sea shelf and the Pearl River Estuary are 68% ± 1% and 30% ± 5%, respectively. This study also confirmed that there were no clear signals of Pu from the Fukushima Daiichi Nuclear Power Plant accident impacting the South China Sea.

Evidence for Prehistoric Astronomy in the Aegean

Science.gov (United States)

Banos, G.

In this study an effort is made to find evidence, based on literary and archaeological sources, for the astronomical knowledge of the people in and around the Aegean in prehistoric times. The main conclusions are: 1) The Minoans, as well as the Mycenaeans, had a calendar, not necessarily the same. The existence of a Mycenaean calendar is well known from the Knossos and Pylos tablets containing a number of months. 2) The Minoans had a luni-solar calendar and a time record system. They used as a basic time unit the time of rise of the solar disc, measured probably through a clepsydre, and the well known gaming board (zatrikion) of the Heraclion Museum as a time-keeper. Bigger units were the day, the lunar months, the year and the octaetiris. 3) The necessary observations were probably made from sites such as the peak sanctuaries in Crete.

Mitochondrial control region haplotypes of the South American sea lion Otaria flavescens (Shaw, 1800

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L.O. Artico

2010-09-01

Full Text Available The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande, both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7, with OFA1 being the most frequent (47.54%. Nucleotide diversity was moderate (π = 0.62% and haplotype diversity was relatively low (67%. Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.

Assessment for water quality by artificial neural network in Daya Bay, South China Sea.

Science.gov (United States)

Wu, Mei-Lin; Wang, You-Shao; Gu, Ji-Dong

2015-10-01

In this study, artificial neural network such as a self-organizing map (SOM) was used to assess for the effects caused by climate change and human activities on the water quality in Daya Bay, South China Sea. SOM has identified the anthropogenic effects and seasonal characters of water quality. SOM grouped the four seasons as four groups (winter, spring, summer and autumn). The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on the water quality in Daya Bay. Spatial pattern is mainly related to anthropogenic activities and hydrodynamics conditions. In spatial characteristics, the water quality in Daya Bay was divided into two groups by chemometrics. The monitoring stations (S3, S8, S10 and S11) were in these area (Dapeng Ao, Aotou Harbor) and northeast parts of Daya Bay, which are areas of human activity. The thermal pollution has been observed near water body in Daya Bay Nuclear Power Plant (S5). The rest of the monitoring sites were in the south, central and eastern parts of Daya Bay, which are areas that experience water exchanges from South China Sea. The results of this study may provide information on the spatial and temporal patterns in Daya Bay. Further research will be carry out more research concerning functional changes in the bay ecology with respect to changes in climatic factor, human activities and bay morphology in Daya Bay.

A comparison of the radioactivity levels in the coastal waters between the great wall and Zhongshan stations in Antarctica and the Pohai, Huanghai, east China and south China seas of China

International Nuclear Information System (INIS)

Chen Jinxing

1992-01-01

A comparison of radioactivity levels in the coastal sediments and plants between the Great Wall and Zhongshan Stations in Antarctica and the four seas (i.e. the Pohai Sea, Huanghai Sea, East China Sea and South China Sea) in China shows that in general the radioactivity levels in the coastal sediments and plants in Antarctica are lower than those in the four seas in China. The contents of the total β in the sediments decrease from higher to lower in amount in the order of East China Sea, South China Sea, Pohai Sea, Huanghai Sea and the Great Wall Bay in Antarctica successively, but the contents of 238 U, 232 Th, 226 Ra, 40 K and the total β in marine plants decrease from higher to lower in amount in the order of Daya Bay in the South China Sea, Hanzhou Bay in the East China Sea and the Great Wall Bay in Antarctica successively. The results show that the contamination levels of radioactivity, especially the artificial radioactive contamination in the Antarctic coastal area are far lower than those in China Coastal area, with the remarkable exception of 137 Cs

Trace Element Accumulation and Tissue Distribution in the Purpleback Flying Squid Sthenoteuthis oualaniensis from the Central and Southern South China Sea.

Science.gov (United States)

Wu, Yan Yan; Shen, Yu; Huang, Hui; Yang, Xian Qing; Zhao, Yong Qiang; Cen, Jian Wei; Qi, Bo

2017-01-01

Sthenoteuthis oualaniensis is a species of cephalopod that is becoming economically important in the South China Sea. As, Cd, Cr, Cu, Hg, Pb, and Zn concentrations were determined in the mantle, arms, and digestive gland of S. oualaniensis from 31 oceanographic survey stations in the central and southern South China Sea. Intraspecific and interspecific comparisons with previous studies were made. Mean concentrations of trace elements analyzed in arms and mantle were in the following orders: Zn > Cu > Cd > Cr > As > Hg. In digestive gland, the concentrations of Cd and Cu exceed that of Zn. All the Pb concentrations were under the detected limit.

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

KAUST Repository

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

2015-01-01

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.

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.

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

Science.gov (United States)

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

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.

Temporal and Spatial Diversity of Bacterial Communities in Coastal Waters of the South China Sea

Science.gov (United States)

Du, Jikun; Xiao, Kai; Li, Li; Ding, Xian; Liu, Helu; Lu, Yongjun; Zhou, Shining

2013-01-01

Bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems. Temporal and geographical patterns in ocean bacterial communities have been observed in many studies, but the temporal and spatial patterns in the bacterial communities from the South China Sea remained unexplored. To determine the spatiotemporal patterns, we generated 16S rRNA datasets for 15 samples collected from the five regularly distributed sites of the South China Sea in three seasons (spring, summer, winter). A total of 491 representative sequences were analyzed by MOTHUR, yielding 282 operational taxonomic units (OTUs) grouped at 97% stringency. Significant temporal variations of bacterial diversity were observed. Richness and diversity indices indicated that summer samples were the most diverse. The main bacterial group in spring and summer samples was Alphaproteobacteria, followed by Cyanobacteria and Gammaproteobacteria, whereas Cyanobacteria dominated the winter samples. Spatial patterns in the samples were observed that samples collected from the coastal (D151, D221) waters and offshore (D157, D1512, D224) waters clustered separately, the coastal samples harbored more diverse bacterial communities. However, the temporal pattern of the coastal site D151 was contrary to that of the coastal site D221. The LIBSHUFF statistics revealed noticeable differences among the spring, summer and winter libraries collected at five sites. The UPGMA tree showed there were temporal and spatial heterogeneity of bacterial community composition in coastal waters of the South China Sea. The water salinity (P=0.001) contributed significantly to the bacteria-environment relationship. Our results revealed that bacterial community structures were influenced by environmental factors and community-level changes in 16S-based diversity were better explained by spatial patterns than by temporal patterns. PMID:23785512

Matching Deep Tow Camera study and Sea Floor geochemical characterization of gas migration at the Tainan Ridge, South China Sea

Science.gov (United States)

Fan, L. F.; Lien, K. L.; Hsieh, I. C.; Lin, S.

2017-12-01

Methane seep in deep sea environment could lead to build up of chemosynthesis communities, and a number of geological and biological anomalies as compare to the surrounding area. In order to examine the linkage between seep anomalies and those at the vicinity background area, and to detail mapping those spatial variations, we used a deep towed camera system (TowCam) to survey seafloor on the Tainan Ridge, Northeastern South China Sea (SCS). The underwater sea floor pictures could provide better spatial variations to demonstrate impact of methane seep on the sea floor. Water column variations of salinity, temperature, dissolved oxygen were applied to delineate fine scale variations at the study area. In addition, sediment cores were collected for chemical analyses to confirm the existence of local spatial variations. Our results show large spatial variations existed as a result of differences in methane flux. In fact, methane is the driving force for the observed biogeochemical variations in the water column, on the sea floor, and in the sediment. Of the area we have surveyed, there are approximately 7% of total towcam survey data showing abnormal water properties. Corresponding to the water column anomalies, underwater sea floor pictures taken from those places showed that chemosynthetic clams and muscles could be identified, together with authigenic carbonate buildups, and bacterial mats. Moreover, sediment cores with chemical anomalies also matched those in the water column and on the sea floor. These anomalies, however, represent only a small portion of the area surveyed and could not be identified with typical (random) coring method. Methane seep, therefore, require tedious and multiple types of surveys to better understand the scale and magnitude of seep and biogeochemical anomalies those were driven by gas migrations.

Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

Science.gov (United States)

Zhai, Hongchang; Ning, Xiuren; Tang, Xuexi; Hao, Qiang; Le, Fengfeng; Qiao, Jing

2011-03-01

Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

Occurrence of persistent organic pollutants in marine fish from the Natuna Island, South China Sea.

Science.gov (United States)

Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

2014-08-15

Five marine fish species were collected from the Natuna Island, South China Sea to investigate the occurrence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs in marine fish ranged from 2.85 to 7.82, 14.3 to 48.1, and 7.99 to 40.3 ng/g lipid weight, respectively. Higher concentrations of PBDEs, PCBs, and DDTs were observed in Snakefish (Trachinocephalus myops), which might be attributed to their different feeding and living habits. PCBs were the predominant POPs in all marine fish, followed by DDTs and PBDEs. BDE 47 and PCB 153 were the predominant congener of PBDEs and PCBs, respectively. Compositional distribution of DDTs indicated the possible presence of fresh input sources around the Natuna Island. The ratios of o,p'-DDT/p,p'-DDT being less than 1 in fish samples suggested that DDT contributions from dicofol seemed considerably low. New input sources of DDT in South China Sea are worth further research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Change in the foraging strategy of female South American sea lions (Carnivora: Pinnipedia after parturition

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Massimiliano Drago

2010-08-01

Full Text Available This study tests the hypothesis that female South American sea lions shift from off-shore, pelagic prey to coastal, benthic prey after parturition in order to reduce the foraging trip duration and hence the time pups remain unattended on the beach during early lactation. The δ13C and δ15N values of the serum and blood cells of 26 South American sea lion suckling pups from northern Patagonia were used to track the dietary changes of their mothers from late pregnancy to early lactation, after correction for differential isotopic fractionation between tissues. Primary producers and potential prey species were also analysed to establish a baseline for interpreting the stable isotope concentration of serum and blood cells. Isotopic ratios revealed a generalized increase in the consumption of coastal-benthic prey after parturition. Such a generalized post-partum shift will allow females to spend more time on land and look after their pups. The effects of this foraging strategy on the nutritional quality of the female’s diet are discussed.

Challenges in Projecting Sea Level Rise impacts on the Coastal Environment of South Florida (Invited)

Science.gov (United States)

Obeysekera, J.; Park, J.; Irizarry-Ortiz, M. M.; Barnes, J. A.; Trimble, P.; Said, W.

2010-12-01

Due to flat topography, a highly transmissive groundwater aquifer, and a growing population with the associated infrastructure, South Florida’s coastal environment is one of the most vulnerable areas to sea level rise. Current projections of sea level rise and the associated storm surges will have direct impacts on coastal beaches and infrastructure, flood protection, freshwater aquifers, and both the isolated and regional wetlands. Uncertainties in current projections have made it difficult for regional and local governments to develop adaptation strategies as such measures will depend heavily on the temporal and spatial patterns of sea level rise in the coming decades. We demonstrate the vulnerability of both the built and natural environments of the coastal region and present the current efforts to understand and predict the sea level rise estimate that management agencies could employ in planning of adaptation strategies. In particular, the potential vulnerabilities of the flood control system as well as the threat to the water supply wellfields in the coastal belt will be presented. In an effort to understand the historical variability of sea level rise, we present linkages to natural phenomena such as Atlantic Multi-Decadal Oscillation, and the analytical methods we have developed to provide probabilistic projections of both mean sea level rise and the extremes.

Continentward-dipping detachment fault system and asymmetric rift structure of the Baiyun Sag, northern South China Sea

Science.gov (United States)

Zhou, Zhichao; Mei, Lianfu; Liu, Jun; Zheng, Jinyun; Chen, Liang; Hao, Shihao

2018-02-01

The rift architecture and deep crustal structure of the distal margin at the mid-northern margin of the South China Sea have been previously investigated by using deep seismic reflection profiles. However, one fundamental recurring problem in the debate is the extensional fault system and rift structure of the hyperextended rift basins (Baiyun Sag and Liwan Sag) within the distal margin because of the limited amount of seismic data. Based on new 3D seismic survey data and 2D seismic reflection profiles, we observe an array of fault blocks in the Baiyun Sag, which were tilted towards the ocean by extensional faulting. The extensional faults consistently dip towards the continent. Beneath the tilted fault blocks and extensional faults, a low-angle, high-amplitude and continuous reflection has been interpreted as the master detachment surface that controls the extension process. During rifting, the continentward-dipping normal faults evolved in a sequence from south to north, generating the asymmetric rift structure of the Baiyun Sag. The Baiyun Sag is separated from the oceanic domain by a series of structural highs that were uplifted by magmatic activity in response to the continental breakup at 33 Ma and a ridge jump to the south at 26-24 Ma. Therefore, we propose that magmatism played a significant role in the continental extension and final breakup in the South China Sea.

Bacterial diversity and biogeography in deep-sea sediments of the South Atlantic Ocean

DEFF Research Database (Denmark)

Schauer, Regina; Bienhold, Christina; Ramette, Alban

2010-01-01

in 1051 sequences. Phylotypes affiliated with Gammaproteobacteria, Deltaproteobacteria and Acidobacteria were present in all three basins. The distribution of these shared phylotypes seemed to be influenced neither by the Walvis Ridge nor by different deep water masses, suggesting a high dispersal......Microbial biogeographic patterns in the deep sea depend on the ability of microorganisms to disperse. One possible limitation to microbial dispersal may be the Walvis Ridge that separates the Antarctic Lower Circumpolar Deep Water from the North Atlantic Deep Water. We examined bacterial...... communities in three basins of the eastern South Atlantic Ocean to determine diversity and biogeography of bacterial communities in deep-sea surface sediments. The analysis of 16S ribosomal RNA (rRNA) gene clone libraries in each basin revealed a high diversity, representing 521 phylotypes with 98% identity...

A parabolic model of drag coefficient for storm surge simulation in the South China Sea

Science.gov (United States)

Peng, Shiqiu; Li, Yineng

2015-01-01

Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models. PMID:26499262

A parabolic model of drag coefficient for storm surge simulation in the South China Sea

Science.gov (United States)

Peng, Shiqiu; Li, Yineng

2015-10-01

Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models.

Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

Directory of Open Access Journals (Sweden)

Shu-Hua Qi

2011-11-01

Full Text Available Five zoanthoxanthin alkaloids (1–5 and four sesquiterpenes (6–9 were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2, 8-hydroxy-6β-methoxy-14-oxooplop-6,12-olide (6 and 3β-methoxyguaian-10(14-en-2β-ol (7 were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae.

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)

Thebault, Herve; Rodriguez y Baena, Alessia M.; Andral, Bruno; Barisic, Delko; Albaladejo, Jose Benedicto; Bologa, Alexandru S.; Boudjenoun, Redouane; Delfanti, Roberta; Egorov, Victor N.; El Khoukhi, Tahar; Florou, Heleni; Kniewald, Goran; Noureddine, Abdelkader

2008-01-01

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

Whole-Body Microbiota of Sea Cucumber (Apostichopus japonicus) from South Korea for Improved Seafood Management.

Science.gov (United States)

Kim, Tae-Yoon; Lee, Jin-Jae; Kim, Bong-Soo; Choi, Sang Ho

2017-10-28

Sea cucumber ( Apostichopus japonicus ) is a popular seafood source in Asia, including South Korea, and its consumption has recently increased with recognition of its medicinal properties. However, because raw sea cucumber contains various microbes, its ingestion can cause foodborne illness. Therefore, analysis of the microbiota in the whole body of sea cucumber can extend our understanding of foodborne illness caused by microorganisms and help to better manage products. We collected 40 sea cucumbers from four different sites in August and November, which are known as the maximum production areas in Korea. The microbiota was analyzed by an Illumina MiSeq system, and bacterial amounts were quantified by real-time PCR. The diversity and bacterial amounts in sea cucumber were higher in August than in November. Alpha-, Beta-, and Gammaproteobacteria were common dominant classes in all samples. However, the microbiota composition differed according to sampling time and site. Staphylococcus warneri and Propionibacterium acnes were commonly detected potential pathogens in August and November samples, respectively. The effect of experimental Vibrio parahaemolyticus infection on the indigenous microbiota of sea cucumber was analyzed at different temperatures, revealing clear alterations of Psychrobacter and Moraxella ; thus, these shifts can be used as indicators for monitoring infection of sea cucumber. Although further studies are needed to clarify and understand the virulence and mechanisms of the identified pathogens of sea cucumber, our study provides a valuable reference for determining the potential of foodborne illness caused by sea cucumber ingestion and to develop monitoring strategies of products using microbiota information.

40Ar/39Ar dating of oceanic plagiogranite: Constraints on the initiation of seafloor spreading in the South China Sea

Science.gov (United States)

Zhong, Li-Feng; Cai, Guan-Qiang; Koppers, Anthony A. P.; Xu, Yi-Gang; Xu, He-Hua; Gao, Hong-Fang; Xia, Bin

2018-03-01

The Cenozoic opening of the South China Sea was one of the most significant tectonic events in SE Asia, coinciding with complex regional rifting, subduction, terrane collision, and large-scale continental strike-slip faulting. The timing of the initiation of seafloor spreading in the South China Sea remains controversial due to a scarcity of incontrovertible age data. This work provides the first report of an oceanic plagiogranite from the Penglai Seamount, located on the 17°N fossil spreading center of the East Sub-basin of the South China Sea, near the Manila Trench. Pyroxene and whole-rock 40Ar/39Ar dating yields ages of 32.3 ± 0.5 Ma and 28.9 ± 1.9 Ma, respectively. The plagiogranite show trace element and isotopic composition similar to those of mid-oceanic ridge basalts (MORB), with 87Sr/86Sr(t) = 0.70394; εNd(t) = 8.21; 206Pb/204Pb = 17.9930, 207Pb/204Pb = 15.4839, 208Pb/204Pb = 37.8852; εHf(t) = 20.95; and γOs(t) = 15.89. It suggested that the rock formed due to differential cooling between adjacent layers of oceanic crust and asthenospheric shearing at the oceanic spreading ridge, resulting in the development of detachment faults. This triggered the subsequent ingress of seawater along the faults, which transformed into a hydrothermal fluid under the influence of shear and geothermal heating, altering the parent gabbro, and leading to the generation of the daughter plagiogranite by anatexis during the early Oligocene. This new geochronology also demonstrates that the initial opening of the South China Sea occurred before 32 Ma, thereby constraining the Cenozoic tectonic evolution of Southeast Asia.

Temperature profile and water depth data collected from COCHRANE in the South China Sea and other seas from 09 January 1987 to 22 February 1987 (NODC Accession 8700095)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the COCHRANE in the South China and other seas. Data were collected from 09 January...

Spatial variability in phytoplankton community structure along the eastern Arabian Sea during the onset of south-west monsoon

Digital Repository Service at National Institute of Oceanography (India)

Ahmed, A.; Kurian, S.; Gauns, M.; ChndrasekharaRao, A.V.; Mulla, A.; Naik, B.; Naik, H.; Naqvi, S.W.A.

The Arabian Sea experiences moderate to weak upwelling along the south-west coast of India, which subsequently propagates towards the north. This causes variation in plankton community composition, which is addressed in the present study. Here we...

Temperature shapes coral-algal symbiosis in the South China Sea

Science.gov (United States)

Tong, Haoya; Cai, Lin; Zhou, Guowei; Yuan, Tao; Zhang, Weipeng; Tian, Renmao; Huang, Hui; Qian, Pei-Yuan

2017-01-01

With the increase in sea surface temperature (SST), scleractinian corals are exposed to bleaching threats but may possess certain flexibilities in terms of their associations with symbiotic algae. Previous studies have shown a close symbiosis between coral the and Symbiodinium; however, the spatial variation of the symbiosis and the attribution underlying are not well understood. In the present study, we examined coral-algal symbiosis in Galaxea fascicularis and Montipora spp. from three biogeographic regions across ~10° of latitude in the South China Sea. Analysis of similarities (ANOSIM) indicated a highly flexible coral-algal symbiosis in both G. fascicularis and Montipora spp. and canonical correspondence analysis (CCA) showed that temperature explained 83.2% and 60.1% of the explanatory subclade variations in G. fascicularis and Montipora spp., respectively, which suggested that temperature was the main environmental factor contributing to the diversity of Symbiodinium across the three regions. The geographic specificity of the Symbiodinium phylogeny was identified, revealing possible environmental selection across the three regions. These results suggest that scleractinian corals may have the ability to regulate Symbiodinium community structures under different temperatures and thus be able to adapt to gradual climate change. PMID:28084322

Understanding the Tectonic Features in the South China Sea By Analyzing Magnetic Anomalies

Science.gov (United States)

Guo, L.; Meng, X.; Shi, L.; Yao, C.

2011-12-01

The South China Sea (SCS) is surrounded by the Eurasia, Pacific and India-Australia plates. It formed during Late Oligocene-Early Miocene, and is one of the largest marginal seas in the Western Pacific. The collision of Indian subcontinent and Eurasian plate in the northwest, back-arc spreading in the centre and subduction beneath the Philippine plate along Manila trench in the east and along Palawan trough in the south had produced the complex tectonic features in the SCS that we can see today. In the past few decades, a variety of geophysical methods were conducted to study geological tectonics and evolution of the SCS. Here, we analyzed the magnetic data of this area using new data enhancement techniques to understand the regional tectonic features. We assembled the magnetic anomalies data with a resolution of two arc-minute from the World Digital Magnetic Anomaly Map, and then gridded the data on a regular grid. Then we used the method of reduction to the pole at low latitude with varying magnetic inclinations to stably reduce the magnetic anomalies. Then we used the preferential continuation method based on Wiener filtering and Green's equivalence principle to separate the reduced-to-pole (RTP) magnetic anomalies, and subsequently analyze the regional and residual anomalies. We also calculated the directional horizontal derivatives and the tilt-angle derivative of the data to derive clearer geological structures with more details. Then we calculated the depth of the magnetic basement surface in the area by 3D interface inversion. From the results of the preliminary processing, we analyzed the main faults, geological structures, magma distribution and tectonic features in the SCS. In the future, the integrated interpretation of the RTP magnetic anomalies, Bouguer gravity anomalies and other geophysical methods will be performed for better understanding the deep structure , the tectonic features and evolution of the South China Sea. Acknowledgment: We

Characterization of aerosol over the Northern South China Sea during two cruises in 2003

Science.gov (United States)

Zhang, Xingying; Zhuang, Guoshun; Guo, Jinghua; Yin, Kedong; Zhang, Peng

Atmospheric transport of trace elements has been found to be an important pathway for their input to the ocean. TSP, PM10, and PM2.5 aerosol samples were collected over the Northern South China Sea in two cruises in 2003 to estimate the input of aerosol from continent to the ocean. About 23 elements and 14 soluble ions in aerosol samples were measured. The average mass concentration of TSP in Cruise I in January (78 μg m -3) was ˜twice of that in Cruise II in April (37 μg m -3). Together with the crustal component, heavy metals from pollution sources over the land (especially from the industry and automobiles in Guangzhou) were transported to and deposited into the ocean. The atmospheric MSA concentrations in PM2.5 (0.048 μg m -3 in Cruise I and 0.043 μg m -3 in Cruise II) over Northern South China Sea were comparable to those over other coastal regions. The ratio of non-sea-salt (NSS)-sulfate to MSA is 103-655 for Cruise I and 15-440 for Cruise II in PM2.5 samples, which were much higher than those over remote oceans. The estimated anthropogenic sulfate accounts for 83-98% in Cruise I and 63-95% in Cruise II of the total NSS-sulfate. Fe (II) concentration in the aerosols collected over the ocean ranged from 0.1 to 0.9 μg m -3, accounting for 16-82% of the total iron in the aerosol, which could affect the marine biogeochemical cycle greatly.

The Role of Atmospheric Heating over the South China Sea and Western Pacific Regions in Modulating Asian Summer Climate under the Global Warming Background

Science.gov (United States)

He, B.

2015-12-01

Global warming is one of the most significant climate change signals at the earth's surface. However, the responses of monsoon precipitation to global warming show very distinct regional features, especially over the South China Sea (SCS) and surrounding regions during boreal summer. To understand the possible dynamics in these specific regions under the global warming background, the changes in atmospheric latent heating and their possible influences on global climate are investigated by both observational diagnosis and numerical sensitivity simulations. Results indicate that summertime latent heating has intensified in the SCS and western Pacific, accompanied by increased precipitation, cloud cover, lower-tropospheric convergence, and decreased sea level pressure. Sensitivity experiments show that middle and upper tropospheric heating causes an east-west feedback pattern between SCS-western Pacific and South Asia, which strengthens the South Asian High in the upper troposphere and moist convergence in the lower troposphere, consequently forcing a descending motion and adiabatic warming over continental South Asia and leading to a warm and dry climate. When air-sea interaction is considered, the simulation results are overall more similar to observations, and in particular the bias of precipitation over the Indian Ocean simulated by AGCMs has been reduced. The results highlight the important role of latent heating in adjusting the changes in sea surface temperature through atmospheric dynamics.

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.

Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

KAUST Repository

Wang, Chang Yun; Chen, An Na; Shao, Chang Lun; Li, Liang; Xu, Ying; Qian, Pei Yuan

2011-01-01

Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1-10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite. © 2011 Elsevier Ltd.

Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

KAUST Repository

Wang, Chang Yun

2011-08-01

Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1-10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite. © 2011 Elsevier Ltd.

New species of the genus Sinularia (Octocorallia: Alcyonacea) from Nha Trang Bay, South China Sea, Vietnam

NARCIS (Netherlands)

Dautova, T.N.; Ofwegen, van L.P.; Savinkin, O.V.

2010-01-01

A total of eight Sinularia species is described and depicted, all from Nha Trang Bay, Vietnam (South China Sea). Six are new to science: S. capricornis, S. multiflora, S. pumila, S. sarmentosa, S. torta, and S. uva. Two other ones represent just new records for Vietnam: S. rigida (Dana, 1846) and S.

Occurrence of Coccolithophorids in the Northeastern and Central South China Sea

Directory of Open Access Journals (Sweden)

Tien-Nan Yang

2003-03-01

Full Text Available Coccolithophorids in the northeastern and central South China Sea (SCS were surveyed in March and October 1996. The cell density of coccolithophorids ranged from 25 x 103 cells L-1 to 31 x 103 cells L-1 in sea-surface water (0–25 m in depth, and from 12 x 103 cells L-1 to 62 x 103 cells L-1 in subsurface water (150 m in depth. The lowest cell number was recorded in the subsurface (150 m in depth in the central gyral area, while the highest one was at the same depth in the northeastern realm. A total of thirty-one species were identified. The species richness in the northeastern SCS is higher than in the central area. Emiliania huxleyi (Lohmann Hay et Mohler, Gephyrocapsa oceanica Kamptner, Umbellosphaera Paasche spp. And Syracosphaera Lohmann spp. Dominated the surface assemblages, whereas Florisphaera profunda Okada et Honjo, Gladiolithus flabellatus (Halldal et Markali Jordan et Chamberlain predominated in the subsurface layer. In contrast, Palusphaera vandeli Lecal emend. R. E. Norris presented in both surface and subsurface assemblages.

Depositional and sea-level history from MIS 6 (Termination II) to MIS 3 on the southern continental shelf of South Africa

Science.gov (United States)

Cawthra, H. C.; Jacobs, Z.; Compton, J. S.; Fisher, E. C.; Karkanas, P.; Marean, C. W.

2018-02-01

Pleistocene shoreline deposits comprised of calcified shallow marine (palaeobeach) and aeolian (palaeodune) facies found along mid-latitude coastlines can be useful indicators of past sea levels. Here, we describe a succession of such deposits that are presently exposed both above (subaerial) and below (submerged) mean sea level along the southern Cape coast of South Africa, 18 km east of the town of Mossel Bay. The submerged units provide a window on Late Pleistocene coastal processes, as palaeoshoreline deposits in this study extend to water depths of up to 55 m on the mid-shelf. Five sedimentary facies were identified in the strata and were compared to modern depositional environments of the local littoral zone, which include aeolian dune, upper shoreface, foreshore, intertidal swash and back-barrier settings. Twenty-two geological units were observed and mapped. Some of these units were directly dated with optically stimulated luminescence (OSL) dating. OSL ages were obtained for ten samples from the subaerial and twelve samples from the submerged deposits. Those geological units not directly dated were interpreted based on sedimentology and field/stratigraphic relationships to dated units. The stratigraphy and chronology of the succession indicates a record of initial deposition during Termination II (T-II) meltwater events, preceding and leading to marine isotope stage (MIS) 5e. Indicators for multiple sea-level fluctuations between MIS 5d and MIS 4, and sediment deposition at the end of MIS 4 and start of MIS 3 are also found. Both regressive and transgressive depositional cycles are well-preserved in the succession. We propose that palaeodune and palaeobeach deposits along the South Coast of South Africa have no clear preference for deposition during sea-level transgressions or regressions. Sediment deposition more closely mirrors the rate of sea level change, with deposition and preservation either during times of rapid sea-level movement, or oscillation

South Polar Skua breeding populations in the Ross Sea assessed from demonstrated relationship with Adélie Penguin numbers

Science.gov (United States)

Wilson, Deborah J.; Lyver, Phil O'B.; Greene, Terry C.; Whitehead, Amy L.; Dugger, Catherine; Karl, Brian J.; Barringer, James R. F.; McGarry, Roger; Pollard, Annie M.; Ainley, David G.

2017-01-01

In the Ross Sea region, most South Polar Skuas (Stercorarius maccormicki) nest near Adélie Penguin (Pygoscelis adeliae) colonies, preying and scavenging on fish, penguins, and other carrion. To derive a relationship to predict skua numbers from better-quantified penguin numbers, we used distance sampling to estimate breeding skua numbers within 1000 m of 5 penguin nesting locations (Cape Crozier, Cape Royds, and 3 Cape Bird locations) on Ross Island in 3 consecutive years. Estimated numbers of skua breeding pairs were highest at Cape Crozier (270,000 penguin pairs; 1099 and 1347 skua pairs in 2 respective years) and lowest at Cape Royds (3000 penguin pairs; 45 skua pairs). The log–log linear relationship (R2 = 0.98) between pairs of skuas and penguins was highly significant, and most historical estimates of skua and penguin numbers in the Ross Sea were within 95 % prediction intervals of the regression. Applying our regression model to current Adélie Penguin colony sizes at 23 western Ross Sea locations predicted that 4635 pairs of skuas now breed within 1000 m of penguin colonies in the Ross Island metapopulation (including Beaufort Island) and northern Victoria Land. We estimate, using published skua estimates for elsewhere in Antarctica, that the Ross Sea South Polar Skua population comprises ~50 % of the world total, although this may be an overestimate because of incomplete data elsewhere. To improve predictions and enable measurement of future skua population change, we recommend additional South Polar Skua surveys using consistent distance-sampling methods at penguin colonies of a range of sizes.

Size Resolved Measurements of Springtime Aerosol Particles over the Northern South China Sea

Science.gov (United States)

Atwood, Samuel A.; Reid, Jeffrey S.; Kreidenweis, Sonia M.; Cliff, Stephen S.; Zhao, Yongjing; Lin, Neng-Huei; Tsay, Si-Chee; Chu, Yu-Chi; Westphal, Douglas L.

2012-01-01

Large sources of aerosol particles and their precursors are ubiquitous in East Asia. Such sources are known to impact the South China Sea (henceforth SCS), a sometimes heavily polluted region that has been suggested as particularly vulnerable to climate change. To help elucidate springtime aerosol transport into the SCS, an intensive study was performed on the remote Dongsha (aka Pratas) Islands Atoll in spring 2010. As part of this deployment, a Davis Rotating-drum Uniform size-cut Monitor (DRUM) cascade impactor was deployed to collect size-resolved aerosol samples at the surface that were analyzed by X-ray fluorescence for concentrations of selected elements. HYSPLIT backtrajectories indicated that the transport of aerosol observed at the surface at Dongsha was occurring primarily from regions generally to the north and east. This observation was consistent with the apparent persistence of pollution and dust aerosol, along with sea salt, in the ground-based dataset. In contrast to the sea-level observations, modeled aerosol transport suggested that the westerly flow aloft (w700 hPa) transported smoke-laden air toward the site from regions from the south and west. Measured aerosol optical depth at the site was highest during time periods of modeled heavy smoke loadings aloft. These periods did not coincide with elevated aerosol concentrations at the surface, although the model suggested sporadic mixing of this free-tropospheric aerosol to the surface over the SCS. A biomass burning signature was not clearly identified in the surface aerosol composition data, consistent with this aerosol type remaining primarily aloft and not mixing strongly to the surface during the study. Significant vertical wind shear in the region also supports the idea that different source regions lead to varying aerosol impacts in different vertical layers, and suggests the potential for considerable vertical inhomogeneity in the SCS aerosol environment.

Symbols, spaces and materiality: a transmission-based approach to Aegean Bronze Age ritual.

OpenAIRE

Briault, C.

2005-01-01

This thesis explores the transmission of ritual practices in the second millennium BC Aegean. In contrast to previous approaches, which often overlook gaps in the diachronic record, emphasising continuity in cult practice over very long timescales, it is argued here that through charting the spatial and temporal distributions of three broad material types (cult symbols, spaces and objects), it is possible to document the spread of cult practice over time and space, and, crucially, to monitor ...

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

International Nuclear Information System (INIS)

Kaldellis, J.K.; Zafirakis, D.

2007-01-01

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

Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

OpenAIRE

Fernández, Araceli; Paz Villanueva, María; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

2014-01-01

Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and inv...

Kinematic parameters of internal waves of the second mode in the South China Sea

Directory of Open Access Journals (Sweden)

O. Kurkina

2017-10-01

Full Text Available Spatial distributions of the main properties of the mode function and kinematic and non-linear parameters of internal waves of the second mode are derived for the South China Sea for typical summer conditions in July. The calculations are based on the Generalized Digital Environmental Model (GDEM climatology of hydrological variables, from which the local stratification is evaluated. The focus is on the phase speed of long internal waves and the coefficients at the dispersive, quadratic and cubic terms of the weakly non-linear Gardner model. Spatial distributions of these parameters, except for the coefficient at the cubic term, are qualitatively similar for waves of both modes. The dispersive term of Gardner's equation and phase speed for internal waves of the second mode are about a quarter and half, respectively, of those for waves of the first mode. Similarly to the waves of the first mode, the coefficients at the quadratic and cubic terms of Gardner's equation are practically independent of water depth. In contrast to the waves of the first mode, for waves of the second mode the quadratic term is mostly negative. The results can serve as a basis for expressing estimates of the expected parameters of internal waves for the South China Sea.

A survey of 137Cs in sediments of the eastern mediterranean marine environment from the pre-Chernobyl age to the present

International Nuclear Information System (INIS)

Evangeliou, Nikolaos; Florou, Heleny; Kritidis, Panayotis

2014-01-01

A survey of 137 Cs in sediments from the eastern Mediterranean Sea (Aegean and Ionian Seas) during the period from 1984 to 2007 is presented. Data have been collected and analyzed in the framework of the monitoring system of Greece performed by the Environmental Radioactivity Laboratory (NCSR 'Demokritos') over the past 30 years. Sediment activities reflect the impact from the Chernobyl accident one year later (1987). It is evident that sediment acts as the final receptor of 137 Cs, showing that fast depollution of the Mediterranean still remains a utopia. Radioactive 'hot spots' were observed in the northern Aegean Sea and lower values in the southern Aegean Sea and Ionian Sea. Finally, an effort to evaluate the risk of ionizing radiation (from 137 Cs) to the biota inhabiting sediments was made using ERICA. The respective dose rates for two reference organisms (benthic fish and mollusks) were estimated to be far below the screening dose, at which the radiological impact on the abundance of the population begins. (authors)

Non-aromatic hydrocarbons in surface sediments near the Pearl River estuary in the South China Sea

International Nuclear Information System (INIS)

Gao Xuelu; Chen Shaoyong; Xie Xueliang; Long Aimin; Ma Fujun

2007-01-01

Surface sediment samples at 4 sites along an offshore transect from outer continental shelf off the Pearl River estuary to the shelf slope region of the northern South China Sea, have been analyzed for total organic carbon (TOC), total nitrogen (TN), solvent extractable organic matter (EOM) and non-aromatic hydrocarbons. TOC, TN and EOM show distinct spatial variations. Their highest values are all recorded at the shelf slope region. EOM varies from 18.70-38.58 μg g -1 dry sediment and accounts for 0.20-0.72% of the TOC contents. The non-aromatic hydrocarbons are an important fraction of EOM. Their contents range from 3.43-7.06 μg g -1 dry sediment. n-Alkanes with carbon number ranging from 15-38 are identified. They derive from both biogenic and petrogenic sources in different proportions. Results of isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. - Anthropogenic activities have influences on the composition of non-aromatic hydrocarbons in the surface sediments of the northern South China Sea outer continental shelf

Briarane Diterpenes from the South China Sea Gorgonian Coral, Junceella gemmacea

Directory of Open Access Journals (Sweden)

Wei Zhou

2014-01-01

Full Text Available Four new briarane diterpenoids, junceellolides M–P (1–4, were isolated together with seven known analogs (5–11 from the South China Sea gorgonian, Junceella gemmacea. The structures of these compounds were elucidated by detailed spectroscopic analysis and comparison with the reported data. The absolute configuration of compounds 1–3 were determined based on an ECD experiment, while the absolute configuration of compound 4 was genetically determined. All the compounds were isolated for the first time from J. gemmacea. These compounds showed no growth inhibitory activity against A549, MG63 and SMMC-7721 cell lines in an in vitro bioassay.

Indo-Pacific sea level variability during recent decades

Science.gov (United States)

Yamanaka, G.; Tsujino, H.; Nakano, H.; Urakawa, S. L.; Sakamoto, K.

2016-12-01

Decadal variability of sea level in the Indo-Pacific region is investigated using a historical OGCM simulation. The OGCM driven by the atmospheric forcing removing long-term trends clearly exhibits decadal sea level variability in the Pacific Ocean, which is associated with eastern tropical Pacific thermal anomalies. During the period of 1977-1987, the sea level anomalies are positive in the eastern equatorial Pacific and show deviations from a north-south symmetric distribution, with strongly negative anomalies in the western tropical South Pacific. During the period of 1996-2006, in contrast, the sea level anomalies are negative in the eastern equatorial Pacific and show a nearly north-south symmetric pattern, with positive anomalies in both hemispheres. Concurrently, sea level anomalies in the south-eastern Indian Ocean vary with those in the western tropical Pacific. These sea level variations are closely related to large-scale wind fields. Indo-Pacific sea level distributions are basically determined by wind anomalies over the equatorial region as well as wind stress curl anomalies over the off-equatorial region.

Academia Sinica, TW E-science to Assistant Seismic Observations for Earthquake Research, Monitor and Hazard Reduction Surrounding the South China Sea

Science.gov (United States)

Huang, Bor-Shouh; Liu, Chun-Chi; Yen, Eric; Liang, Wen-Tzong; Lin, Simon C.; Huang, Win-Gee; Lee, Shiann-Jong; Chen, Hsin-Yen

Experience from the 1994 giant Sumatra earthquake, seismic and tsunami hazard have been considered as important issues in the South China Sea and its surrounding region, and attracted many seismologist's interesting. Currently, more than 25 broadband seismic instruments are currently operated by Institute of Earth Sciences, Academia Sinica in northern Vietnam to study the geodynamic evolution of the Red river fracture zone and rearranged to distribute to southern Vietnam recently to study the geodynamic evolution and its deep structures of the South China Sea. Similar stations are planned to deploy in Philippines in near future. In planning, some high quality stations may be as permanent stations and added continuous GPS observations, and instruments to be maintained and operated by several cooperation institutes, for instance, Institute of Geophysics, Vietnamese Acadamy of Sciences and Technology in Vietnam and Philippine Institute of Volcanology and Seismology in Philippines. Finally, those stations will be planed to upgrade as real time transmission stations for earthquake monitoring and tsunami warning. However, high speed data transfer within different agencies is always a critical issue for successful network operation. By taking advantage of both EGEE and EUAsiaGrid e-Infrastructure, Academia Sinica Grid Computing Centre coordinates researchers from various Asian countries to construct a platform to high performance data transfer for huge parallel computation. Efforts from this data service and a newly build earthquake data centre for data management may greatly improve seismic network performance. Implementation of Grid infrastructure and e-science issues in this region may assistant development of earthquake research, monitor and natural hazard reduction. In the near future, we will search for new cooperation continually from the surrounding countries of the South China Sea to install new seismic stations to construct a complete seismic network of the

Statistics of Acoustic Pulse Signals Through Nonlinear Internal Waves on the Continental Shelf of the Northeastern South China Sea

National Research Council Canada - National Science Library

Reeves, Justin M

2008-01-01

...) was conducted from 13 - 15 April 2005 on the continental shelf in the northeast portion of the South China Sea to study the effects of nonlinear internal waves on the transmission of a 400-Hz signal...

Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea

KAUST Repository

Wang, Chao-Yi; Wang, Kai-Ling; Ghosheh, Yanal; Xu, Ying; Chen, Min; Zheng, Juan-Juan; Liu, Min; Shao, Chang-Lun; Wang, Chang-Yun

2016-01-01

for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds

Reconstruction of Local Sea Levels at South West Pacific Islands—A Multiple Linear Regression Approach (1988-2014)

Science.gov (United States)

Kumar, V.; Melet, A.; Meyssignac, B.; Ganachaud, A.; Kessler, W. S.; Singh, A.; Aucan, J.

2018-02-01

Rising sea levels are a critical concern in small island nations. The problem is especially serious in the western south Pacific, where the total sea level rise over the last 60 years has been up to 3 times the global average. In this study, we aim at reconstructing sea levels at selected sites in the region (Suva, Lautoka—Fiji, and Nouméa—New Caledonia) as a multilinear regression (MLR) of atmospheric and oceanic variables. We focus on sea level variability at interannual-to-interdecadal time scales, and trend over the 1988-2014 period. Local sea levels are first expressed as a sum of steric and mass changes. Then a dynamical approach is used based on wind stress curl as a proxy for the thermosteric component, as wind stress curl anomalies can modulate the thermocline depth and resultant sea levels via Rossby wave propagation. Statistically significant predictors among wind stress curl, halosteric sea level, zonal/meridional wind stress components, and sea surface temperature are used to construct a MLR model simulating local sea levels. Although we are focusing on the local scale, the global mean sea level needs to be adjusted for. Our reconstructions provide insights on key drivers of sea level variability at the selected sites, showing that while local dynamics and the global signal modulate sea level to a given extent, most of the variance is driven by regional factors. On average, the MLR model is able to reproduce 82% of the variance in island sea level, and could be used to derive local sea level projections via downscaling of climate models.

Salinification in the South China Sea Since Late 2012: A Reversal of the Freshening Since the 1990s

Science.gov (United States)

Zeng, Lili; Chassignet, Eric P.; Schmitt, Raymond W.; Xu, Xiaobiao; Wang, Dongxiao

2018-03-01

Salinification has occurred in the South China Sea from late 2012 to the present, as shown by satellite Aquarius/Soil Moisture Active Passive data and Argo float data. This salinification follows a 20 year freshening trend that started in 1993. The salinification signal is strongest near the surface and extends downward under the seasonal thermocline to a depth of 150 m. The salinification occurs when the phase of the Pacific Decadal Oscillation switches from negative to positive. Diagnosis of the salinity budget suggests that an increasing net surface freshwater loss and the horizontal salt advection through the Luzon Strait driven by the South China Sea throughflow contributed to this ongoing salinification. In particular, a decrease in precipitation and enhanced Luzon Strait transport dominated the current intense salinification. Of particular interest is whether this salinification will continue until it reaches the previous maximum recorded in 1992.

Tides and Their Dynamics over the Sunda Shelf of the Southern South China Sea.

Science.gov (United States)

Daryabor, Farshid; Ooi, See Hai; Abu Samah, Azizan; Akbari, Abolghasem

2016-01-01

A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performed on the inner domain. The model is forced at the sea surface by climatological monthly mean wind stress, freshwater (evaporation minus precipitation), and heat fluxes. Momentum and tracers (such as temperature and salinity) are prescribed in addition to the tidal heights and currents extracted from the Oregon State University TOPEX/Poseidon Global Inverse Solution (TPXO7.2) at the open boundaries. The results are validated against observed tidal amplitudes and phases at 19 locations. Results show that the mean average power energy spectrum (in unit m2/s/cph) for diurnal tides at the southern end of the East Coast of Peninsular Malaysia is approximately 43% greater than that in the East Malaysia region located in northern Borneo. In contrast, for the region of northern Borneo the semidiurnal power energy spectrum is approximately 25% greater than that in the East Coast of Peninsular Malaysia. This implies that diurnal tides are dominant along the East Coast of Peninsular Malaysia while both diurnal and semidiurnal tides dominate almost equally in coastal East Malaysia. Furthermore, the diurnal tidal energy flux is found to be 60% greater than that of the semidiurnal tides in the southern South China Sea. Based on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area.

Seasonal and interannual variability of the Mid-Holocene East Asian monsoon in coral δ18O records from the South China Sea

Science.gov (United States)

Sun, Donghuai; Gagan, Michael K.; Cheng, Hai; Scott-Gagan, Heather; Dykoski, Carolyn A.; Edwards, R. Lawrence; Su, Ruixia

2005-08-01

Understanding the full range of past monsoon variability, with reference to specific monsoon seasons, is essential to test coupled climate models and improve their predictive capabilities. We present a 54-year long, high-resolution skeletal oxygen isotope (δ18O) record extracted from a well-preserved, massive Porites sp. coral at Hainan Island, South China Sea, to investigate East Asian monsoon variability during summer and winter ∼4400 calendar yr ago. Analysis of modern coral δ18O confirms that Porites from Hainan Island are well positioned to record winter monsoon forcing of sea surface temperature (SST), as well as the influence of summer monsoon rainfall on sea surface salinity (SSS). The coral record for ∼4400 yr ago shows ∼9% amplification of the annual cycle of δ18O, in good agreement with coupled ocean-atmosphere models showing higher summer rainfall (lower coral δ18O) and cooler winter SSTs (higher coral δ18O) in response to greater Northern Hemisphere insolation seasonality during the Middle Holocene. Mean SSTs in the South China Sea during the Mid-Holocene were within 0.5 °C of modern values, yet the mean δ18O for the fossil coral is ∼0.6‰ higher than that for the modern coral, suggesting that the δ18O of surface seawater was higher by at least ∼0.5‰, relative to modern values. The 18O-enrichment is likely to be driven by greater advection of moisture towards the Asian landmass, enhanced monsoon wind-induced evaporation and vertical mixing, and/or invigorated advection of saltier 18O-enriched Pacific water into the relatively fresh South China Sea. The 18O-enrichment of the northern South China Sea ∼4400 yr ago contributes to mounting evidence for recent freshening of the tropical Western Pacific. Today, winter SST and summer SSS variability in the South China Sea reflect the interannual influence of ENSO and the biennial variability inherent to monsoon precipitation. Spectral analysis of winter SSTs ∼4400 yr ago reveals a

Classifying Vessels Operating in the South China Sea by Origin with the Automatic Identification System

Science.gov (United States)

2018-03-01

p. 5) means to track voyage and safety related information in real time. Over time, massive amounts of information related to maritime operations... safety related messages from land based stations, navigation aids, and search and rescue (SAR) crews. All AIS messages are intended to encourage open...United States is the South China Sea. Eight countries, China, Taiwan, the Philippines, Brunei, Indonesia, Malaysia , Singapore, and Vietnam

Analysis of calibrated sea clutter and boat reflectivity data at C- and X-band in South African coastal waters

CSIR Research Space (South Africa)

Herselman, PLR

2007-10-01

Full Text Available datasets of sea clutter returns at different frequencies, range resolutions, grazing angles, look angles and environmental conditions to validate the state-of-the-art sea clutter models on South African coastal seawaters. Secondly, the aim was to record... boat reflectivity datasets for a number of small boats to investigate its detectability with state-of-the-art detectors. This will lead to the development of improved detection algorithms for radar systems employing adaptive dwell times. Figure 1...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from OCEAN RESEARCHER I in the Philippine Sea and South China Sea from 1991-07-08 to 1991-07-12 (NCEI Accession 0143948)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0143948 includes discrete sample and profile data collected from OCEAN RESEARCHER I in the Philippine Sea and South China Sea (Nan Hai) from...

The origin of gas seeps and shallow gas in northern part of South China Sea

Science.gov (United States)

Li, M.; Jin, X.

2003-04-01

The northern part of South China Sea is of passive continental margin, which geologic units include shelf, slope and deep sea basin. There are rifting basins forming during Paleogene (or Cretaceous ?) to Quaternary developed on shelf and slope, which sediments are dominated by fluvial and lake clastic rock of Paleogene, and marine clastic rock and carbonate of Neogene - Quaternary. The main basins include the Pearl River Mouth Basin, Beibu Gulf basin, Qiongdongnan Basin and Yinggehai basin. They contain rich oil and gas resources, and have become important industrial oil and gas producing region in South China Sea. With the increasing of petroleum exploration actives and marine petroleum engineering, it has been paid more attention to the investigation and research of gas seeps and shallow gas, for they become a potential threaten to the marine engineering while they are regarded as the indicators of industrial oil and gas. By study the distribution and geochemical characteristics of gas seeps in northeast part of Yinggehai basin and shallow gas in sediments on slope, combined with their regional geologic background, this paper deals with the origin, migration pathway and emission mechanism of gas seeps and shallow gas in northern part of South China Sea, for providing a base knowledge for the evaluation of marine engineering geology. In northeast part of Yinggehai basin gas seeps have been found and recorded for near 100 years. During 1990s, as a part of petroleum exploration, the gas seeps in the basin have been investigated and research by oil companies (Baojia Huang et al., 1992; Jiaqiong He et al., 2000). Gas seeps were found in shallow water area along southwest coast of Hainan Island, water depth usually less than 50 m. The occurrence of gas seeps can be divided into two types: (1) gas continuously emission, continuous gas bubbles groups can be detected by sonar underwater and observed on water surface. (2) gas intermittently emission, the time intervals

Description of dogs naturally infected with Hepatozoon canis in the Aegean region of Turkey

OpenAIRE

PAŞA, Serdar; KIRAL, Funda; KARAGENÇ, Tülin; ATASOY, Abidin; SEYREK, Kamil

2009-01-01

Clinical and laboratory findings recorded in 10 dogs naturally infected with Hepatozoon canis in the Aegean region of Turkey were reported. The diagnosis was made by finding H. canis gamonts within leucocytes in Giemsa-stained blood smears. H. canis parasitaemia level was calculated manually by counting 500 neutrophils in blood smears. Parasitaemia varied from 1% to 23% of the circulating neutrophils. Anorexia, fever, depression, weight loss, and lymphadenopathy are the main clinical signs in...

Transport of terrigenous polycyclic aromatic hydrocarbons affected by the coastal upwelling in the northwestern coast of South China Sea.

Science.gov (United States)

Ya, Miaolei; Wu, Yuling; Li, Yongyu; Wang, Xinhong

2017-10-01

Coastal upwelling prevails in the coast of Hainan Island, the northern South China Sea (SCS) during summer. We studied the influences of the upwelling on the horizontal and vertical transport of terrigenous polycyclic aromatic hydrocarbons (PAHs). PAHs in dissolved and suspended particulate phase of water samples were determined in the upper (depth  10 m). PAH levels decreased sharply from inshore to offshore to open sea. The results showed that terrestrial input was the main source of coastal PAHs. Perylene, an important indicator of land plant-derived PAH, showed the significant correlation with PAHs (p sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biogeographical distribution and diversity of bacterial communities in surface sediments of the South China Sea.

Science.gov (United States)

Li, Tao; Wang, Peng

2013-05-01

This paper aims at an investigation of the features of bacterial communities in surface sediments of the South China Sea (SCS). In particular, biogeographical distribution patterns and the phylogenetic diversity of bacteria found in sediments collected from a coral reef platform, a continental slope, and a deep-sea basin were determined. Bacterial diversity was measured by an observation of 16S rRNA genes, and 18 phylogenetic groups were identified in the bacterial clone library. Planctomycetes, Deltaproteobacteria, candidate division OP11, and Alphaproteobacteria made up the majority of the bacteria in the samples, with their mean bacterial clones being 16%, 15%, 12%, and 9%, respectively. By comparison, the bacterial communities found in the SCS surface sediments were significantly different from other previously observed deep-sea bacterial communities. This research also emphasizes the fact that geographical factors have an impact on the biogeographical distribution patterns of bacterial communities. For instance, canonical correspondence analyses illustrated that the percentage of sand weight and water depth are important factors affecting the bacterial community composition. Therefore, this study highlights the importance of adequately determining the relationship between geographical factors and the distribution of bacteria in the world's seas and oceans.

Lagrangian Observations of Nonlinear Internal Waves and Turbulence Mixing in Luzon Strait and South China Sea and Internal Wave in the Vicinity of the Kuroshio Path

National Research Council Canada - National Science Library

Lien, Ren-Chieh; D'Asaro, Eric A

2008-01-01

... mixing in the northern South China Sea. Results are reported. The second was to analyze observations of data taken in the vicinity of the Kuroshio path from Luzon Strait to the southern East China Sea...

Case Study: The Myanmar and Bangladesh Maritime Boundary Dispute in the Bay of Bengal and Its Implications for South China Sea Claims

Directory of Open Access Journals (Sweden)

Ravi A. Balaram

2012-01-01

Full Text Available This paper seeks to review the pertinent Myanmar and Bangladesh history in overlapping maritime territorial claims leading up to the September 2011 International Tribunal for the Law of the Sea (ITLOS case: Dispute Concerning Delimitation of the Maritime Boundary Between Bangladesh and Myanmar in the Bay of Bengal. It will dissect the legal proceedings as primary source documents and apply the relevant judgement findings to analyse the implications for the respective countries and for South China Sea maritime boundary disputes. While the judgements of this case set certain legal precedents that may be more easily applied to bilateral disputes, the implications, nevertheless, impinge on multilateral claims as well. To the extent that the Bangladesh-Myanmar ITLOS judgement provides a pathway to third-party, independent, and peaceful resolution to the potentially explosive and escalating tensions in the South China Sea, this paper argues that findings are relevant, but limited.

Tearing, segmentation, and backstepping of subduction in the Aegean: New insights from seismicity

Science.gov (United States)

Bocchini, G. M.; Brüstle, A.; Becker, D.; Meier, T.; van Keken, P. E.; Ruscic, M.; Papadopoulos, G. A.; Rische, M.; Friederich, W.

2018-06-01

This study revisits subduction processes at the Hellenic Subduction Zone (HSZ) including tearing, segmentation, and backstepping, by refining the geometry of the Nubian slab down to 150-180 km depth using well-located hypocentres from global and local seismicity catalogues. At the western termination of the HSZ, the Kefalonia Transform Fault marks the transition between oceanic and continental lithosphere subducting to the south and to the north of it, respectively. A discontinuity is suggested to exist between the two slabs at shallow depths. The Kefalonia Transform Fault is interpreted as an active Subduction-Transform-Edge-Propagator-fault formed as consequence of faster trench retreat induced by the subduction of oceanic lithosphere to the south of it. A model reconstructing the evolution of the subduction system in the area of Peloponnese since 34 Ma, involving the backstepping of the subduction to the back-side of Adria, provides seismological evidence that supports the single-slab model for the HSZ and suggests the correlation between the downdip limit of the seismicity to the amount of subducted oceanic lithosphere. In the area of Rhodes, earthquake hypocentres indicate the presence of a NW dipping subducting slab that rules out the presence of a NE-SW striking Subduction-Transform-Edge-Propagator-fault in the Pliny-Strabo trenches region. Earthquake hypocentres also allow refining the slab tear beneath southwestern Anatolia down to 150-180 km depth. Furthermore, the distribution of microseismicity shows a first-order slab segmentation in the region between Crete and Karpathos, with a less steep and laterally wider slab segment to the west and a steeper and narrower slab segment to the east. Thermal models indicate the presence of a colder slab beneath the southeastern Aegean that leads to deepening of the intermediate-depth seismicity. Slab segmentation affects the upper plate deformation that is stronger above the eastern slab segment and the seismicity

{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.

Tides and their dynamics over the Sunda Shelf of the southern South China Sea

DEFF Research Database (Denmark)

Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

2016-01-01

A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performe...... on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area....

South Florida’s Encroachment of the Sea and Environmental Transformation over the 21st Century

Directory of Open Access Journals (Sweden)

Joseph Park

2017-07-01

Full Text Available South Florida encompasses a dynamic confluence of urban and natural ecosystems strongly connected to ocean and freshwater hydrologic forcings. Low land elevation, flat topography and highly transmissive aquifers place both communities at the nexus of environmental and ecological transformation driven by rising sea level. Based on a local sea level rise projection, we examine regional inundation impacts and employ hydrographic records in Florida Bay and the southern Everglades to assess water level exceedance dynamics and landscape-relevant tipping points. Intrinsic mode functions of water levels across the coastal interface are used to gauge the relative influence and time-varying transformation potential of estuarine and freshwater marshes into a marine-dominated environment with the introduction of a Marsh-to-Ocean transformation index (MOI.

Restoration of sea eagle population: A review

Directory of Open Access Journals (Sweden)

Josef RAJCHARD

2009-10-01

Full Text Available The population density of the white-tailed sea eagle Haliaeetus albicilla is very low in many countries. In last twenty years, the sea eagle population in South Bohemia was restored by strict protection subsidized by reintroduction. The active help consisted of feeding during winter and building of artificial nests. A new sea eagle breeding population arose in the Třeboň basin area in the early 1980’s. Until this time sea eagles had used former breeding places only for wintering, probably coming from the Baltic. The South Bohemian sea eagle population is very unique: it exists in a densely man-occupied landscape, mainly in areas with very intensive carp breeding in artificial fishponds and was partly artficially (help to wintering birds and reintroduction of some individuals restored. The experience from South Bohemia may have importance for populations of the sea eagle in other areas of its occurence, primarily in the continental conditions [Current Zoology 55 (5:–2009].

A new species of Eunice (Polychaeta: Eunicidae) from Hainan Island, South China Sea

Science.gov (United States)

Wu, Xuwen; Sun, Ruiping; Liu, Ruiyu

2013-01-01

A taxonomic survey of benthic marine animals from coastal regions of Hainan Island, South China Sea, revealed specimens of a new species of Eunice (Polychaeta: Eunicida: Eunicidae), Eunice uschakovi n. sp., collected from the intertidal zone. The species belongs to the group of Eunice that has yellow tridentate subacicular hooks and branchiae scattered over an extensive region of the body. It resembles E. miurai and E. havaica in having both bidentate and tridentate falcigers, but can be readily distinguished by branchial features. Comparisons between E. uschakovi and the two related species are presented.

Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

Directory of Open Access Journals (Sweden)

L. M. Dupont

2011-11-01

Full Text Available Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean ∼120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome for the last glacial as well as for other glacial periods of the past 300 Ka.

Temporal variation and biomagnification of organohalogen compounds in finless porpoises (Neophocaena phocaenoides) from the South China Sea

International Nuclear Information System (INIS)

Ramu, Karri; Kajiwara, Natsuko; Lam, Paul K.S.; Jefferson, Thomas A.; Zhou Kaiya; Tanabe, Shinsuke

2006-01-01

Polybrominated diphenyl ethers (PBDEs) and organochlorine compounds (OCs) were determined in the blubber of male finless porpoises (Neophocaena phocaenoides) collected in 1990 and 2000/01 from the South China Sea. Among the organohalogen compounds analyzed, DDTs and PCBs were the predominant contaminants in the porpoises, ranging from 26,000 to 260,000 and 1400 to 28,000 ng/g lipid wt., respectively. PBDEs ranged from a minimum of 84 ng/g lipid wt., in 1990 to a maximum of 980 ng/g lipid wt., in 2001, showing a significant increase during the time period investigated. Congener profiles in finless porpoises did not shift to higher BDE congeners during these years, implying a continuous discharge of lower BDE commercial mixtures, such as PentaBDE. For OCs, HCHs concentrations decreased significantly, while others did not exhibit any significant temporal variation. Biomagnification factors (BMFs) were found to be highest for CHLs and lowest for HCB. PBDEs and PCBs had comparable BMFs, indicating a similar potential for biomagnification through the food web. - Levels and temporal variations of organohalogen contaminants in the South China Sea

Reef coral δ18O thermometer in Hainan island waters, south China sea

International Nuclear Information System (INIS)

He Xuexian; Peng Zicheng; Wang Zhaorong; Huo Weiguo; Tan Jun; Nie Baofu; Chen Tegu; Zhong Jinliang

2000-01-01

An 18-year-long (1981-1998) study was conducted in Hainan Island waters (22 degree 22'N, 110 degree 39'E) to determine the relationship between δ 18 O in skeletal aragonite carbonate and sea surface temperature (SST) in porites lutea of reef-building corals. δ 18 O values in skeletal aragonite carbonate were measured by means of mass spectrometry. Coral samples grew at 5 m depth at Longwan Bay. Monthly measurements of the SST from 1960 to 1998 were taken at Qinglan Bay adjacent to the place of the collected samples. The thermometer shows that SST = -4.16 δ 18 O PDB + 4.9 (r = 0.80) and dδ 18 O/dT = -0.24 per mil/degree C. The δ 18 O thermometer is strongly influenced by the rainfall and runoff. Using the thermometer, the SST in the past hundred years with monthly resolution will be reconstructed and the climatic change in the northern area of South China Sea will be hind cast

Response of internal solitary waves to tropical storm Washi in the northwestern South China Sea

Directory of Open Access Journals (Sweden)

Z. H. Xu

2011-11-01

Full Text Available Based on in-situ time series data from an array of temperature sensors and an acoustic Doppler current profiler on the continental shelf of the northwestern South China Sea, a sequence of internal solitary waves (ISWs were observed during the passage of tropical storm Washi in the summer of 2005, which provided a unique opportunity to investigate the ISW response to the tropical cyclone. The passing tropical storm is found to play an important role in affecting the stratification structure of the water column, and consequently leading to significant variability in the propagating features of the ISWs, such as the polarity reversal and amplitude variations of the waves. The response of the ISWs to Washi can be divided into two stages, direct forcing by the strong wind (during the arrival of Washi and remote forcing via the near-inertial internal waves induced by the tropical storm (after the passage of Washi. The field observations as well as a theoretical analysis suggest that the variations of the ISWs closely coincide with the changing stratification structure and shear currents in accompanied by the typhoon wind and near-inertial waves. This study presents the first observations and analysis of the ISW response to the tropical cyclone in the South China Sea.

SEA for strategic grid planning in South Africa: Enabling the efficient and effective roll out of strategic electricity transmission infrastructure

CSIR Research Space (South Africa)

Fischer, TD

2016-05-01

Full Text Available | Resilience and Sustainability 36th Annual Conference of the International Association for Impact Assessment 11 - 14 May 2016 | Nagoya Congress Center | Aichi-Nagoya | Japan | www.iaia.org SEA FOR STRATEGIC GRID PLANNING IN SOUTH AFRICA: Enabling... the efficient and effective roll out of strategic electricity transmission infrastructure Abstract ID: 409 Authors: Marshall Mabin(1) , Paul Lochner and Dee Fischer Council for Scientific and Industrial Research (CSIR), PO Box 320 Stellenbosch 7599 South...

Weak depth and along-strike variations in stretching from a multi-episodic finite stretching model: Evidence for uniform pure-shear extension in the opening of the South China Sea

Science.gov (United States)

Chen, Lin; Zhang, Zhongjie; Song, Haibin

2013-12-01

The South China Sea is widely believed to have been opened by seafloor spreading during the Cenozoic. The details of its lithospheric extension are still being debated, and it is unknown whether pure, simple, or conjunct shears are responsible for the opening of the South China Sea. The depth-dependent and along-strike extension derived from the single-stage finite stretching model or instantaneous stretching model is inconsistent with the observation that the South China Sea proto-margins have experienced multi-episodic extension since the Late Cretaceous. Based on the multi-episodic finite stretching model, we present the amount of lithosphere stretching at the northern continental margin of the South China Sea for different depth scales (upper crust, whole crust and lithosphere) and along several transects. The stretching factors are estimated by integrating seven deep-penetration seismic profiles, the Moho distribution derived from gravity modeling, and the tectonic subsidence data for 41 wells. The results demonstrate that the amount of stretching increases rapidly from 1.1 at the continent shelf to over 3.5 at the lower slope, but the stretching factors at the crust and lithosphere scales are consistent within error (from the uncertainty in paleobathymetry and sea-level change). Furthermore, the along-strike variation in stretching factor is within the range of 1.11-1.9 in west-east direction, accompanied by significant west-east differences in the thickness of high-velocity layers (HVLs) within the lowermost crust. This weak along-strike variation of the stretching factor is most likely produced by the preexisting contrasts in the composition and thermal structure of the lithosphere. The above observations suggest that the continental extension in the opening of the South China Sea mainly takes the form of a uniform pure shear rather than depth-dependent stretching.

Energy balance and cost analysis for raisin production in Aegean Region in Turkey

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Uysal Hülya

2016-01-01

Full Text Available The aim of this study is to determine energy consumption of input and output used in raisin production and making a cost analysis in Aegean Region. Energy output-input analysis is generally done to determine the scope of environment and energy efficiency of agricultural production. In this study the cost of raisin production was calculated by Manisa Viticulture Research Institute's records in 2015. Costs of inputs and prices of raisin were obtained from various sources such as Turkish Statistical Institute, Aegean Exporters' Association and Turkish Ministry of Food, Agriculture and Livestock. The total energy input necessity for raisin production was 39,066.91 MJ/ha. The research results indicated that the total energy input used for raisin was mainly dependent on non-renewable energy forms (%97. The high ratio of non-renewable energy in the total used energy inputs causes negative effects on the sustainability in agricultural production. Among input energy sources, diesel oil, chemical fertilizers and electricity contained highest energy shares with 34.30%, 26.96%, and 22.50% respectively. The energy ratio and energy productivity were found to be 6.04 and 0.51 kg/MJ. Gross production value and total variable costs for raisin were $ 8,600 and $ 4,528.25, respectively. As a result of cost analysis, gross margin was calculated as $ 4,071.75.

Genetic architecture of the marbled goby Pomatoschistus marmoratus (Perciformes, Gobiidae) in the Mediterranean Sea.

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Mejri, Randa; Arculeo, Marco; Hassine, Oum Kalthoum Ben; Brutto, Sabrina Lo

2011-02-01

The marbled goby Pomatoschistus marmoratus, a species inhabiting coastal Mediterranean lagoons, has been studied by measuring its mitochondrial DNA variation. This analysis revealed a Mediterranean west vs east split and, subsequently, an eastern differentiation among the Libyan-Tunisian Gulf, the Adriatic Sea and the Aegean Sea. The high cohesion between the samples collected in the vast area of western Mediterranean contrasts with the genetic mosaic of the more sub-structured eastern Mediterranean. This western homogeneity can not yet be fully explained even if a human-mediated migratory flow, due to a maritime traffic, has been posited. The pattern in the eastern basin revealed a genetic architecture possibly due to the non-migratory habit of the gobid. Within this perspective, the role of the Mediterranean lagoon habitat should be related to how much it amplifies the effects of historical (e.g. past sea-level changes) and environmental (e.g. present-day hydrographic regime) processes as regards the genetic structure of the inhabiting species. Copyright © 2010 Elsevier Inc. All rights reserved.

Wave modelling south of the Danube Delta in the Black Sea

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Rusu, Eugen; Butunoiu, Dorin

2015-04-01

A multilevel wave modelling system, based on SWAN (Simulating Waves Nearshore) spectral model, was implemented in the Black Sea and focused on the western coast. Model simulations have been performed for a 10-year time interval (1999-2008). Validations have been carried out against both satellite data and in situ measurements. A high resolution SWAN computational domain (100m x100m), which is focused on the coastal environment south of the Danube Delta, was also implemented. This coastal area includes Sacalin, which is a newly formed island in the Black Sea, south of the Saint George branch of the Danube. Initially, this was an island system, which consisted of two smaller islands, Greater Sacalin and Lesser Sacalin. In time, due to the enhanced sedimentary processes, the two islands merged into a single continuous landmass. The island has become the habitat of a great variety of rare species and for this reason it was declared an ecological reserve. In the high resolution computational domain, focused on the Sacalin Island, the effect of the currents induced by the Danube River outflow was also accounted in the model, together with some other processes specific to the coastal environment as diffraction, triad wave-wave interactions and wave induced set up. Considering the results of the ten-year SWAN model simulations with the modelling system covering the entire sea basin, the most relevant configurations of the environmental matrix, characteristic to this side of the sea, were defined. On this basis, by performing SWAN simulations in the high resolution coastal domain, the wave propagation patterns in the nearshore, together with some parameters related to the shoreline conditions, were evaluated. A great number of possible situations were analyzed. The most relevant correspond to different directions of the incoming waves (N, NE, E and SE, respectively) and significant wave energy conditions. The results provided by the modelling system indicate two different

Arctic and Antarctic Oscillation signatures in tropical coral proxies over the South China Sea

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D.-Y. Gong

2009-05-01

Full Text Available Arctic Oscillation (AO and Antarctic Oscillation (AAO are the leading modes of atmospheric circulation in mid-high latitudes. Previous studies have revealed that the climatic influences of the two modes are dominant in extra-tropical regions. This study finds that AO and AAO signals are also well recorded in coral proxies in the tropical South China Sea. There are significant interannual signals of AO and AAO in the strontium (Sr content, which represents the sea surface temperature (SST. Among all the seasons, the most significant correlation occurs during winter in both hemispheres: the strongest AO-Sr and AAO-Sr coral correlations occur in January and August, respectively. This study also determined that the Sr content lags behind AO and AAO by 1–3 months. Large-scale anomalies in sea level pressure and horizontal wind at 850 hPa level support the strength of AO/AAO-coral teleconnections. In addition, a comparison with oxygen isotope records from two coral sites in neighboring oceans yields significant AO and AAO signatures with similar time lags. These results help to better understand monsoon climates and their teleconnection to high-latitude climate changes.

Influence of Tropical South Atlantic Sea Surface Temperatures on the Indian Summer monsoon in CMIP5 models

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Kucharski, Fred; Joshi, Manish K.

2017-04-01

In this study the teleconnection from the tropical south Atlantic to the Indian monsoon has been assessed in observations and in 32 models from the World Climate Research Program (WCRP) Coupled Model Intercomparison Project Phase 5 (CMIP5). All models show that the regression pattern of tropics-wide Atlantic sea surface temperature (SST) anomalies onto the tropical south Atlantic index correlates well with that in observations, even though with varying spatial standard deviations. However, only about half of the 32 models considered show the correct sign of rainfall response over India to a warm anomaly in the south tropical Atlantic, which is a reduction of rainfall. On the other hand, models generally do show large-scale responses broadly consistent with the observations, and the signal over India depends on relatively subtle changes in the response. This response to a tropical south Atlantic warm (cold) anomaly is a low-level quadrupole in streamfunction with an anticyclonic (cyclonic) anomaly over the Arabian Sea and India. This anticyclonic (cyclonic) anomaly leads to a weakening (strengthening) of the Somali jet and low-level divergence (convergence) over India, both inducing a reduction (increase) of Indian rainfall. The models which do not show the correct rainfall response over India also show a response similar to the one indicated above, but with maximum of the anticyclonic (cyclonic) response shifted to the western Pacific. The large-scale Walker circulation adjustment to the tropical south Atlantic SST anomalies is identified as one of the factors which account for the differences in the low-level streamfunction response. Models (and the observations) with the correct sign of the rainfall signal over India show the dominant upper-level convergence (divergence) as response to a warm (cold) tropical south Atlantic in the western Pacific region, whereas models with the wrong sign of the rainfall signal show it predominantly in the central-eastern Pacific

Ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of South American sea lion (Otaria flavescens.