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Sample records for eastern japan sea

  1. Modeling of the branches of the Tsushima Warm Current in the eastern Japan sea

    International Nuclear Information System (INIS)

    Kawamura, Hideyuki; Ito, Toshimichi; Hirose, Naoki; Yoon, Jong-Hwan; Takikawa, Tetsutaro

    2009-01-01

    The branches of the Tsushima Warm Current (TWC) are realistically reproduced using a three-dimensional ocean general circulation model (OGCM). Simulated structures of the First Branch and the Second Branch of the TWC (FBTWC and SBTWC) in the eastern Japan Sea are mainly addressed in this study, being compared with measurement in the period September-October 2000. This is the first numerical experiment so far in which the OGCM is laterally exerted by real volume transports measured by acoustic Doppler current profiler (ADCP) through the Tsushima Straits and the Tsugaru Strait. In addition, sea level variation measured by tide-stations along the Japanese coast as well as satellite altimeters is assimilated into the OGCM through a sequential data assimilation method. It is demonstrated that the assimilation of sea level variation at the coastal tide-stations is useful in reproducing oceanic conditions in the nearshore region. We also examine the seasonal variation of the branches of the TWC in the eastern Japan Sea in 2000. It is suggested as a consequence that the FBTWC is continuous along northwestern Honshu Island in summertime, while it degenerates along the coast between the Sado Strait and the Oga Peninsula in other seasons. On the other hand, a mainstream of the SBTWC exists with meanders and eddies in the offshore region deeper than 1000 m to the north of the Sado Island throughout the year. (author)

  2. The occurrence of macro- and mesoscopic methane hydrate in the eastern margin of Japan Sea

    Science.gov (United States)

    Matsumoto, R.; Kakuwa, Y.; Tanahashi, M.; Hiruta, A.

    2016-12-01

    Shallow methane hydrate is known to occur in muddy sediments that were deposited in the eastern margin of Japan Sea. In such settings, the hydrate occurs just below the seabed or is exposed directly on the seabed. Its presence is quite different from the pore-filling type of hydrate typically found in sandstone of the Pacific Ocean side of the Japanese islands. This presentation focuses on categorizing the distribution of gas hydrate in Japan Sea which, until recently, has been poorly understood. Macroscopic occurrence: Numerous gas chimney structures, which are characterized by an acoustic blanking on sub-bottom profiler images, have been discovered in the eastern margin of Japan Sea. We carried out seafloor drilling at several topographic highs that showed gas chimney structures. The results confirm that, while methane hydrate does not occur in the well-stratified part of SBP images, it does occur uniquely in the gas chimney structure-bearing mounds and pockmarks. Several horizons of methane hydrate-concentrated layers are identified by our LWD data and are traceable over lateral distances of as much as a kilometer.. In another case, the methane hydrate-concentrated layers occur stratigraphically in a regular manner with methane-derived carbonate nodules. We interpret the second case as one in which methane gas was supplied by regularly repeated movements of active fault(s). Mesoscopic occurrence: Methane hydrate is classified into 5 types that are readily observable in drilled cores: granular, nodular, platy, veiny and massive. The granular type is common over shallower intervals, while platy and veiny types are more common in the deeper intervals. Nevertheless, a significant fraction of the granular type may have possibly originated from the destruction and dissociation of other types during drilling and recovery. The massive type hydrate that characterizes highly-concentrated layers transitions to other types laterally as methane hydrate becomes poorly

  3. Thick massive gas hydrate deposits were revealed by LWD in Off-Joetsu area, eastern margin of Japan Sea.

    Science.gov (United States)

    Tanahashi, M.; Morita, S.; Matsumoto, R.

    2016-12-01

    GR14 and HR15 survey cruises, which were dedicated to the LWD (Logging While Drilling), were carried out in summers of 2014 and 2015, respectively, by Meiji University and Geological Survey of Japan, AIST to explore the "gas chimney" structures in eastern margin of Japan Sea. Shallow (33 to 172m-bsf, average 136m-bsf) 33 LWD drilling were performed in Oki Trough, Off-Joetsu, and Mogami Trough areas along eastern margin of Japan Sea during two cruises. Schlumberger LWD tools, GeoVISION (resistivity), TeleScope, ProVISION (NMR) and SonicVISION were used during GR14. NeoScope (neutron) was added and SonicScope was replaced for SonicVISION during HR14. The data quality was generally good. "Gas chimney" structures with acoustic blanking columns on the high frequency seismic sections with mound and pockmark morphologic features on the sea bottom, are well developed within survey areas. Every LWD records taken from gas chimney structures during the cruises show high resistivity and acoustic velocity anomalies which suggest the development of gas hydrate. Characteristic development of massive gas hydrate was interpreted at the Umitaka CW mound structure, Off-Joetsu. The mound lies at 890-910m in water depth and has very rough bottom surface, regional high resistivity, regional high heat flow, several natural seep sites, 200m x 300m area, and 10-20m height. 8 LWD holes, J18L to J21L and J23L to J26L, were drilled on and around the mound. There are highly anomalous intervals which suggest the development of massive gas hydrate at J24L, with high resistivity, high Vp and Vs, high neutron porosity, low natural gamma ray intensity, low neutron gamma density, low NMR porosity, low NMR permeability, low formation sigma, from 10 to 110m-bsf with intercalating some thin less hydrate layers. It is interpreted that there is several tens of meter thick massive gas hydrate in the gas chimney mound. It is partly confirmed by the later nearby coring result which showed the repetition of

  4. Two deep-sea decapod crustaceans collected off eastern Hokkaido, Japan: Sclerocrangon rex n. sp. (Caridea: Crangonidae) and Munidopsis verrilli Benedict, 1902 (Anomura: Munidopsidae).

    Science.gov (United States)

    Komai, Tomoyuki; Matsuzaki, Koji

    2016-09-08

    Two species of decapod crustaceans collected from deep sea off eastern Hokkaido, Japan, are reported. Sclerocrangon rex n. sp. (Caridea: Crangonidae) is described and illustrated on the basis of material collected off Kushiro and in the Nemuro Strait at depths of 500-1000 m. It is morphologically similar to S. derjugini Kobjakova, 1936 and S. igarashii Komai & Amaoka, 1991, both occurring in waters off eastern Hokkaido, but is easily distinguished from the latter two by the possession of an extra spine on the postorbital carina on the carapace, located posterior to the level of hepatic spines. The second, Munidopsis verrilli Benedict, 1902 (Anomura: Munidopsidae), is the first representative of this squat lobster family to be recorded from northern Japan. The single specimen of M. verrilli was collected in the Nemuro Strait off Shiretoko Peninsula at depths of 700-1000 m.

  5. Japan nuclear ship sea trial

    International Nuclear Information System (INIS)

    Yamazaki, Hiroshi; Kitamura, Toshikatus; Mizushima, Toshihiko

    1992-01-01

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

  6. Constraints of gas venting activity for the interstitial water geochemistry at the shallow gas hydrate site, eastern margin of the Japan Sea; results from high resolution time-series fluid sampling by OsmoSampler

    Science.gov (United States)

    Owari, S.; Tomaru, H.; Matsumoto, R.

    2016-12-01

    We have conducted ROV researches in the eastern margin of the Japan Sea where active gas venting and outcropping of gas hydrates were observed near the seafloor and have found the strength and location of venting had changed within a few days. These observations indicate the seafloor environments with the shallow gas hydrate system could have changed for short period compared to a geological time scale. We have applied a long-term osmotic fluid sampling system "OsmoSampler" on the active gas hydrate system for one year in order to document how the gas venting and gas hydrate activity have changed the geochemical environments near the seafloor. All the major ion concentrations in the interstitial water show synchronous increase and decrease repeatedly in three to five days, reflecting the incorporation and release of fresh water in gas hydrates in response to the gas concentration change near the sampling site. Dissolved methane concentration increases rapidly and excessively (over several mM) in the first 40 days corresponding to the active gas venting. The increases of methane concentration are often associated with high ion concentration during high water pressure period, indicating excess gas release from shallow gas pockets. Contrarily, enhanced gas hydrate growth may plug the fluid-gas paths in shallow sediment, reducing gas hydrate formation due to the decrease of methane flux. This study was conducted under the commission from AIST as a part of the methane hydrate research project funded by METI (the Ministry of Economy, Trade and Industry, Japan).

  7. Sea-ice production in the northern Japan Sea

    Science.gov (United States)

    Nihashi, Sohey; Ohshima, Kay I.; Saitoh, Sei-Ichi

    2017-09-01

    Sinking of the dense water plays a significant role in the global climate system by driving thermohaline (overturning) circulation and biogeochemical cycles. Deep water convection occurs also in the Japan Sea, and the convection has been considered to be mainly caused by intense cooling of the sea surface. Another possible cause of the convection is brine rejection associated with high sea-ice production in a coastal polynya (thin sea-ice) area in the northern Japan Sea. We have developed an algorithm which detects the thin ice area and estimates the thickness using passive microwave satellite data. Based on a heat flux calculation with the satellite-derived ice thickness, the total sea-ice production in winter (December-March) averaged over 2002/03-2010/11 is estimated to be 4.27 × 1010 m3. This indicates that the ice production was underestimated by about half in a previous study in which the polynya was unrealistically treated as a low ice concentration area. The main determinant factor for the total ice production is the surface air temperature in early winter (December-January), which shows a rapid warming trend of 0.7 °C/decade for this 40-years. Based on a linear regression approach, the total ice production is estimated to have decreased by 5%/decade due to air temperature warming. If brine rejection due to the ice production contributes to the deep water formation in the Japan Sea, this is consistent with the fact that the deep water formation has been decreasing for the last 50-100 years.

  8. Big mantle wedge, anisotropy, slabs and earthquakes beneath the Japan Sea

    Science.gov (United States)

    Zhao, Dapeng

    2017-09-01

    The Japan Sea is a part of the western Pacific trench-arc-backarc system and has a complex bathymetry and intense seismic activities in the crust and upper mantle. Local seismic tomography revealed strong lateral heterogeneities in the crust and uppermost mantle beneath the eastern margin of the Japan Sea, which was determined using P and S wave arrival times of suboceanic earthquakes relocated precisely with sP depth phases. Ambient-noise tomography revealed a thin crust and a thin lithosphere beneath the Japan Sea and significant low-velocity (low-V) anomalies in the shallow mantle beneath the western and eastern margins of the Japan Sea. Observations with ocean-bottom seismometers and electromagnetometers revealed low-V and high-conductivity anomalies at depths of 200-300 km in the big mantle wedge (BMW) above the subducting Pacific slab, and the anomalies are connected with the low-V zone in the normal mantle wedge beneath NE Japan, suggesting that both shallow and deep slab dehydrations occur and contribute to the arc and back-arc magmatism. The Pacific slab has a simple geometry beneath the Japan Sea, and earthquakes occur actively in the slab down to a depth of ∼600 km beneath the NE Asian margin. Teleseismic P and S wave tomography has revealed that the Philippine Sea plate has subducted aseismically down to the mantle transition zone (MTZ, 410-660 km) depths beneath the southern Japan Sea and the Tsushima Strait, and a slab window is revealed within the aseismic Philippine Sea slab. Seismic anisotropy tomography revealed a NW-SE fast-velocity direction in the BMW, which reflects corner flows induced by the fast deep subduction of the Pacific slab. Large deep earthquakes (M > 7.0; depth > 500 km) occur frequently beneath the Japan Sea western margin, which may be related to the formation of the Changbai and Ulleung intraplate volcanoes. A metastable olivine wedge is revealed within the cold core of the Pacific slab at the MTZ depth, which may be related

  9. Particle tracking in the eastern Irish Sea

    Science.gov (United States)

    Wolf, Judith; Amoudry, Karen; Phillips, Hazel; Brown, Jenny

    2017-04-01

    The unstructured grid finite volume community ocean model (FVCOM) has been applied to the west coast of the UK, in order to examine the circulation and transport in the eastern Irish Sea. Tides, freshwater river discharge and meteorological forcing for the year 2008 were used to force the baroclinic hydrodynamic circulation. The hydrodynamics of the Irish Sea are largely governed by the semidiurnal tide, which has a tidal range reaching 10m at Liverpool is the eastern Irish Sea. Tidal currents reach 1 ms-1 over the majority of the area, which means that much of Irish Sea is vertically well-mixed throughout the year period, with a few areas affected by seasonal stratification, such as the cyclonic gyre in the deep channel off Ireland in the western Irish Sea which experiences thermal stratification in summer. In Liverpool Bay, horizontal density gradients, created through freshwater influence from estuaries along the coastline interact with the strong tidal current to produce a phenomenon known as strain-induced periodic stratification (SIPS). There are water quality concerns due to the tendency to eutrophication, as the area is often exposed to industrial pollution and excess nutrients from effluent waters and rivers. There is also concern about the fate of radioactive materials discharged from the Sellafield nuclear reprocessing plant since 1952. In addition to the present discharges from the site, it has been estimated that it is likely that all of the americium and plutonium and around 10% of the caesium entering the Irish Sea were originally assimilated into deposits of silt and mud sediments; this material may be regarded as a considerable potential source of radionuclides. Determining suspended sediment pathways in this region is important in order to identify potential areas vulnerable to deposition of radioactive material, particularly as radionuclide uptake onto sediments takes place in the offshore 'mud patch' before returning to the coast to be deposited

  10. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  11. Formation rate of water masses in the Japan Sea

    International Nuclear Information System (INIS)

    Kawamura, Hideyuki; Ito, Toshimichi; Yoon, Jong-Hwan

    2007-01-01

    Water masses in the subsurface and the intermediate layer are actively formed due to strong winter convection in the Japan Sea. It is probable that some fraction of pollution is carried into the layer below the sea surface together with these water masses, so it is important to estimate the formation rate and turnover time of water masses to study the fate of pollutants. The present study estimates the annual formation rate and the turnover time of water masses using a three-dimensional ocean circulation model and a particle chasing method. The total annual formation rate of water masses below the sea surface amounted to about 3.53±0.55 Sv in the Japan Sea. Regarding representative intermediate water masses, the annual formation rate of the Upper portion of the Japan Sea Proper Water (UJSPW) and the Japan Sea Intermediate Water (JSIW) were estimated to be about 0.38±0.11 and 1.43±0.16 Sv, respectively, although there was little evidence of the formation of deeper water masses below a depth of about 1500 m in a numerical experiment. An estimate of turnover time shows that the UJSPW and the JSIW circulate in the intermediate layer of the Japan Sea with timescales of about 22.1 and 2.2 years, respectively. (author)

  12. Radiation safety in sea transport of radioactive material in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Odano, N. [National Maritime Research Inst., Tokyo (Japan); Yanagi, H. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

    2004-07-01

    Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured.

  13. Radiation safety in sea transport of radioactive material in Japan

    International Nuclear Information System (INIS)

    Odano, N.; Yanagi, H.

    2004-01-01

    Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured

  14. Hydrography of the eastern Arabian Sea during summer monsoon ...

    Indian Academy of Sciences (India)

    Arabian Sea, between the onset and wane of the 1995 southwest monsoon; Deep-Sea Res. II 50 2049–2075. Bruce J G, Johnson D R and Kindle J C 1994 Evidence for eddy formation in the eastern Arabian Sea during the northeast monsoon; J. Geophys. Res. 99 7651–7664. Durand F, Shetye S R, Vialard J, Shankar D, ...

  15. Biogeochemical significance of eddies of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; DineshKumar, P.K.; Nair, M.

    Within the Arabian Sea, the western part is considered to be highly productive when compared to the northern, central and eastern parts of the basin. Despite the contrasting chlorophyll and primary productivity patterns, sediment trap data show...

  16. Balance of anthropogenic radionuclides in the Japan Sea

    International Nuclear Information System (INIS)

    Tsuneyama, Teppei; Ito, Toshimichi; Otosaka, Shigeyoshi

    2007-01-01

    Concentration data of 90 Sr, 137 Cs and 239+240 Pu between 1960 and 2002 were examined to estimate the balance of anthropogenic radionuclides in water of the Japan Sea. Until 1960s, they had accumulated mainly in the upper layer of the Japan Sea. After that, the amount of the radionuclides decreased as a result of termination of global fallout and exchange of surface water. The trend turned into increase since 1980s and the amounts will continue to increase for a while. (author)

  17. Study on tsunami due to offshore earthquakes for Korea coast. Literature survey and numerical simulation on earthquake and tsunami in the Japan Sea and the East China Sea

    International Nuclear Information System (INIS)

    Matsuyama, Masafumi; Aoyagi, Yasuhira; Inoue, Daiei; Choi, Weon-Hack; Kang, Keum-Seok

    2008-01-01

    In Korea, there has been a concern on tsumami risks for the Nuclear Power Plants since the 1983 Nihonkai-Chubu earthquake tsunami. The maximum run-up height reached 4 m to north of the Ulchin nuclear power plant site. The east coast of Korea was also attacked by a few meters high tsunami generated by the 1993 Hokkaido Nansei-Oki earthquake. Both source areas of them were in the areas western off Hokkaido to the eastern margin of the Japan Sea, which remains another tsunami potential. Therefore it is necessary to study tsunami risks for coast of Korea by means of geological investigation and numerical simulation. Historical records of earthquake and tsunami in the Japan Sea were re-compiled to evaluate tsunami potential. A database of marine active faults in the Japan Sea was compiled to decide a regional potential of tsunami. Many developed reverse faults are found in the areas western off Hokkaido to the eastern margin of the Japan Sea. The authors have found no historical earthquake in the East China Sea which caused tunami observed at coast of Korea. Therefore five fault models were determined on the basis of the analysis results of historical records and recent research results of fault parameter and tunami. Tsunami heights were estimated by numerical simulation of nonlinear dispersion wave theory. The results of the simulations indicate that the tsunami heights in these cases are less than 0.25 m along the coast of Korea, and the tsunami risk by these assumed faults does not lead to severe impact. It is concluded that tsunami occurred in the areas western off Hokkaido to the eastern margin of the Japan Sea leads the most significant impact to Korea consequently. (author)

  18. Marine protected areas in the high seas of the Aegean and Eastern Mediterranean Seas, some proposals

    OpenAIRE

    Öztürk, Bayram

    2015-01-01

    Abstract Marine living resources are diminishing in the Aegean and Eastern Mediterranean Sea and marine biological diversity is facing various threats such as overfishing, ship originated pollution, exotic species and by-catch.Designation of High Sea Marine Protected Areas [HSMPA] is believed will improve protection of the marine biodiversity in the Eastern Mediterranean including the Aegean Sea. Concerted action and international cooperation is needed for the joint management effort in the E...

  19. Modelling travel and residence times in the eastern Irish Sea

    International Nuclear Information System (INIS)

    Dabrowski, T.; Hartnett, M.

    2008-01-01

    The Irish Sea, which lies between 51 deg. N-56 deg. N and 2 deg. 50'W-7 deg. W, provides a sheltered environment to exploit valuable fisheries resource. Anthropogenic activity is a real threat to its water quality. The majority of freshwater input down rivers flows into the eastern Irish Sea. The structure of the water circulation was not well understood during the planning of Sellafield nuclear plant outfall site in the eastern Irish Sea. A three-dimensional primitive equation numerical model was applied to the Irish Sea to simulate both barotropic and baroclinic circulation within the region. High accuracy was achieved with regard to the prediction of both tidal circulation and surface and nearbed water temperatures across the region. The model properly represented the Western Irish Sea Gyre, induced by thermal stratification and not known during planning Sellafield. Passive tracer simulations based on the developed hydrodynamic model were used to deliver residence times of the eastern Irish Sea region for various times of the year as well as travel times from the Sellafield outfall site to various locations within the Irish Sea. The results indicate a strong seasonal variability of travel times from Sellafield to the examined locations. Travel time to the Clyde Sea is the shortest for the autumnal tracer release (90 days); it takes almost a year for the tracer to arrive at the same location if it is released in January. Travel times from Sellafield to Dublin Bay fall within the range of 180-360 days. The average residence time of the entire eastern Irish Sea is around 7 months. The areas surrounding the Isle of Man are initially flushed due to a predominant northward flow; a backwater is formed in Liverpool Bay. Thus, elevated tracer concentrations are predicted in Liverpool Bay in the case of accidental spills at the Sellafield outfall site

  20. Damages at Japanese assisted reproductive technology clinics by the Great Eastern Japan Earthquake of 2011.

    Science.gov (United States)

    Ishihara, Osamu; Yoshimura, Yasunori

    2011-06-30

    The Great Eastern Japan Earthquake of 2011 and consequent tsunami affected many IVF clinics in northeastern Japan. Twelve clinics lost at least one embryo, but all the frozen embryos stored in liquid nitrogen tanks were safe. Emergency power supply is the first priority issue in an unpredictable natural disaster. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. A High Resolution Normal Mode Solution of Japan Sea

    Science.gov (United States)

    Wu, Y.; Satake, K.

    2014-12-01

    Normal mode calculation of a semi-closed or completely closed bay or ocean basin helps us to understand the oscillation characteristics including those excited by incoming tsunamis. In addition, tsunami propagation can be synthesized by superposition of normal modes. Japan Sea is an almost closed ocean basin where many large tsunamigenic earthquakes occurred (fig. 1). Satake and Shimazaki (1988) calculated the normal modes using a 20km grid (~10' or about 2,000 ocean grids), compared the observed and calculated normal modes from the 1964 Niigata and 1983 Japan Sea earthquakes, and discussed the their different excitation characteristics . Because of development of computer and numerical computation techniques, it is worthwhile to revisit this problem. Starting from Laplace's tidal equations and ignoring the rotation of the earth, Loomis (1975) discretized the problem into the eigenvalue problem of a symmetric sparse matrix, which was solved by Householder transformations. This method is used by Satake and Shimazaki (1988) for Japan Sea and Aida (1996) for Tokyo Bay. However, this method needs O(n^3) operation in time and O(n^2) in memory (n is the total number of water grid. e.g., for Japan Sea in 30 sec grid, n~10^6), which would require a super computer.To overcome this disadvantage, we first introduce a recent iteration method called Implicitly Restarted Arnoldi Method (Lehoucq et al., 1997), which itself speeds up the calculation a bit. Then after we develop a sparse version of matrix storage and multiplication, the operation count in time and memory reduced dramatically to O(n^1.5) (including about 0.5 for iteration process) and O(n) respectively, utilizing the special property of the matrix and the iteration method. This means any current computer can easily solve a large eigenvalue problem. Earthquakes.png

  2. Neogene dinocyst zonation for the eastern North Sea Basin, Denmark

    DEFF Research Database (Denmark)

    Dybkjær, Karen; Piasecki, Stefan

    2010-01-01

    A dinocyst zonation for the Neogene succession in the eastern part of the North Sea Basin (Denmark) is presented. The zonation is based on an extensive database comprising data from more than fifty onshore and offshore boreholes and about twenty five outcrops. Most of the nineteen dinocyst zones ...

  3. Summer monsoon intraseasonal oscillation over eastern Arabian Sea

    Indian Academy of Sciences (India)

    The time evolution of atmospheric parameters on intraseasonal time scale in the eastern Arabian. Sea (EAS) is studied during the summer monsoon seasons of 1998–2003 using Tropical Rainfall. Measuring Mission Microwave Imager (TMI) data. This is done using the spectral and wavelet analysis. Analysis shows that ...

  4. SEA SURFACE TEMPERATURE and Other Data from MULTIPLE SHIPS From Sea of Japan from 19930101 to 19930630 (NODC Accession 9300173)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The sea surface temperature data in this accession was collected in Sea of Japan. Data in this accession was collected over a six month period from thermistor. The...

  5. Historical bottle data collected from the Sea of Okhotsk, Bering Sea, Japan Sea, and North Pacific Ocean by multiple Russian, Former Soviet Union, and Japan platforms in 1888 - 1936 years (NODC Accession 0101422)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical bottle data collected from the Sea of Okhotsk,Bering Sea, Japan Sea, and North Pacific Ocean in 1888 - 1936 years by multiple Russian, Former Soviet...

  6. Currents in the Eastern Irish Sea

    International Nuclear Information System (INIS)

    Howarth, M.J.

    1983-01-01

    Low level radioactive waste is discharged from the nuclear re-processing plant at Sellafield, Cumbria. Its movement away from the discharge point is determined by the Irish Sea's dynamics, both for the soluble compounds and for those compounds which become attached to the sediment. Near Sellafield the tidal currents are weak and parallel to the shore, becoming stronger east/west to the north and south of the Isle of Man. Wind driven currents near Sellafield are predominantly north-westward, strongest near the coast, and oppose the other low frequency currents. Hence, the soluble effluent will initially be dispersed parallel to the shore by the weak tidal currents, moving episodically, southeastward during weak winds and northwestward during storms. Eventually it will leave the Irish Sea, flowing northward through the North Channel. (author)

  7. Henricia djakonovi sp. nov. (Echinodermata, Echinasteridae: a new sea star species from the Sea of Japan

    Directory of Open Access Journals (Sweden)

    Anton Chichvarkhin

    2017-01-01

    Full Text Available A new sea star species, H. djakonovi sp.n., was discovered in Rudnaya Bay in the Sea of Japan. This is a sympatric species of the well-known and common species Henricia pseudoleviuscula Djakonov, 1958. Both species are similar in body size and proportions, shape of skeletal plates, and life coloration, which distinguishes them from the other Henricia species inhabiting the Sea of Japan. Nevertheless, these species can be distinguished by their abactinal spines: in both species, they are short and barrel-like, but the new species is the only Henricia species in Russian waters of the Pacific that possesses such spines with a massive, smooth, bullet-like tip. The spines in H. pseudoleviuscula are crowned with a variable number of well-developed thorns. About half (<50% of the abactinal pseudopaxillae in the new species are oval, not crescent-shaped as in H. pseudoleviuscula.

  8. Satellite observations of circulation in the Eastern Bering Sea

    Science.gov (United States)

    Paluszkiewicz, Theresa; Niebauer, H. J.

    1984-01-01

    Satellite infrared observations of the eastern Bering Sea shelf and basin were analyzed from December 1979 to August 1981. A region of warm surface water which extends from the Gulf of Alaska through the Aleutian Passes into the Bering Sea was observed coincident with a band of warm surface water and with eddies along the shelf break. The spatial and temporal relationships of these patterns imply a surface inflow through Unimak and other western Aleutian Passes, flow along the shelf break including eddies along the Bering Slope Current, and cyclonic flow in the basin. The proposed generating mechanisms for eddies along the shelf break include topographic interactions, baroclinic instabilities, and Rossby waves.

  9. Characteristics of the Japanese sea cucumber Apostichopus japonicus's population in the Sea of Japan (Kievka Bay)

    Science.gov (United States)

    Gavrilova, G. S.; Sukhin, I. Yu.

    2011-06-01

    In Kievka Bay of the Sea of Japan, the population of the Japanese sea cucumber Apostichopus japonicus inhabits the areas of coarse sediments and complex bottom topography. These distributional patterns are closely related to the species' ecology, i.e., to the demand for protection against the wave turbulence. The aggregationing coverage of the sea cucumber population is about 80 hectares, where ˜200 thousand animals were accounted for in the last years. The aggregation's area varies during the year, which is closely related to the species' biological peculiarities, such as their behavioral patterns and the redistribution of their food resources. A significant increase of the juvenile population occurred after the farm-reared sea cucumber spat were released in 2003.

  10. Provenance Changes Over Glacial-Interglacial Timescales Recorded in Japan Sea Sediments (IODP Site U1430)

    Science.gov (United States)

    Kinsley, C. W.; McGee, D.; Anderson, C. H.; Murray, R. W.; Tada, R.; Alvarez Zarikian, C. A.

    2017-12-01

    Recent work has shown a mechanistic relationship between the Westerly Jet (WJ) and East Asian Monsoon (EAM) precipitation, as migration of the WJ to the northern edge of the Tibetan Plateau during spring and early summer appears to be essential for driving convective rainfall over eastern China. Chiang et al. (2015) has proposed the "Jet Transition Hypothesis" wherein it is put forward that changes to the seasonal meridional position of the WJ relative to the Tibetan Plateau drives rainfall climate changes over East Asia on paleoclimate timescales. This hypothesis would predict that in extreme scenarios such as cold phases of Dansgaard-Oeschger (D-O) stadials and during periods of low Northern Hemisphere summer insolation that the Jet would not move north of the Tibetan Plateau, keeping East Asia in prolonged spring conditions. Conversely, during periods of high Northern Hemisphere summer insolation it would be predicted that the Jet would move more quickly north of the Tibetan Plateau and remain there longer, keeping East Asia in prolonged summer conditions. Westerly Jet behavior can be reconstructed using sediments from the Japan Sea, as the WJ path and intensity determines dust emissions and transport paths from Chinese and Mongolian dust source areas, which is the primary source of terrigenous material to the Japan Sea. Radiogenic isotopes of Pb, Nd and Sr can be been applied to fingerprint the dust sources from Asia, and measurements of these isotopes downcore in the Japan Sea will allow reconstruction of the changing dust source area and thus behavior of the WJ. By coupling dust reconstructions lending insight to the behavior of the Westerly Jet with complementary records reflecting EAM intensity and precipitation distribution, the mean state and variability of the WJ and its coupling with the EAM can be examined. This study will measure a suite of samples for Pb, Nd and Sr isotopes from IODP Site U1430 over glacial-interglacial timescales, allowing detailed

  11. Chemical composition of Eastern Black Sea aerosol--preliminary results.

    Science.gov (United States)

    Balcılar, Ilker; Zararsız, Abdullah; Kalaycı, Yakup; Doğan, Güray; Tuncel, Gürdal

    2014-08-01

    Trace element composition of atmospheric particles collected at a high altitude site on the Eastern Black Sea coast of Turkey was investigated to understand atmospheric transport of pollutants to this semi-closed basin. Aerosol samples were collected at a timber-storage area, which is operated by the General Directorate of Forestry. The site is situated at a rural area and is approximately 50 km to the Black Sea coast and 200 km to the Georgia border of Turkey. Coarse (PM2.5-10) and fine (PM2.5) aerosol samples were collected between 2011 and 2013 using a "stacked filter unit". Collected samples were shipped to the Middle East Technical University in Ankara, where Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Ba, Pb were measured by Energy dispersive x-ray fluorescence technique (EDXRF). Comparison of measured concentrations of elements with corresponding data generated at other parts of Turkey demonstrated that concentrations of pollution derived elements are higher at Eastern Black Sea than their corresponding concentrations measured at other parts of Turkey, which is attributed to frequent transport of pollutants from north wind sector. Positive matric factorization revealed four factors including three anthropogenic and a crustal factor. Southeastern parts of Turkey, Georgia and Black Sea coast of Ukraine were identified as source regions affecting composition of particles at our site, using trajectory statistics, namely "potential source contribution function" (PSCF). Copyright © 2013 Elsevier B.V. All rights reserved.

  12. The Great Eastern Japan Earthquake and Tsunami : Facts and implications for flood risk management

    NARCIS (Netherlands)

    Jonkman, S.N.; Kolen, B.; Van Alphen, J.; Stroeks, R.; Tsimopoulou, V.

    2012-01-01

    The Great Eastern Japan Earthquake and Tsunami of March 11, 2011 can be characterized as a catastrophe. It inundated over 560 km2 of land, devastating a large number of coastal communities, causing over 19,000 casualties and huge economic damage in the Tohoku region. Due to the relatively high

  13. Japan Sea expeditions for studies on water circulation and transport processes of radionuclides

    International Nuclear Information System (INIS)

    Togawa, Orihiko; Ito, Toshimichi; Kobayashi, Takuya; Otosaka, Shigeyoshi; Suzuki, Takashi

    2006-02-01

    The Japan Sea expeditions at the Japan Atomic Energy Agency (JAEA from October 1, 2005, former JAERI: Japan Atomic Energy Research Institute until September 30, 2005) were started on its participation in the first and second Japanese-Korean-Russian joint expeditions in 1994 and 1995 to investigate the situation on marine pollution due to radioactive wastes dumped in the Japan Sea and other seas around Japan. After the joint expeditions, JAEA continued to conduct the Japan Sea expeditions not only to monitor the impacts of radioactive wastes dumped in the Japan Sea, but also to investigate water circulation and the migration behavior of radionuclides in the Japan Sea. Taking account of some difficulties and constraints due to the political boundaries in the Japan Sea, the expeditions were carried out, separating the sea into two regions; one is the Japanese exclusive economical zone (EEZ) and the other is the Russian EEZ. The data of observations and measurements obtained in the two regions were analyzed together. The program of the Japan Sea expeditions included large-volume seawater sampling at different depths and seabed sediment sampling for measurements of representative anthropogenic radionuclides. To investigate the migration behavior of the radionuclides more in detail, associated oceanographic observations were also implemented; CTD/MBS (conductivity-temperature-depth meter with multi-bottle sampler) casts, analysis of dissolved oxygen and nutrients, deployment and recovery of mooring systems with current meters and sediment traps, and so on. Additional seawater samples were taken with CTD/MBS for further analysis on land. This report summarizes the results of the Japan Sea expeditions (Phase 1) conducted and/or jointed by JAEA from 1994 to 2002. First the report explains oceanographic features of the Japan Sea, main expeditions in the past and the summarized results of the Japanese-Korean-Russian joint expeditions. Then the report gives an outline of the

  14. Seismic Structure of the Eastern Alboran Sea, Western Mediterranean

    Science.gov (United States)

    Leuchters, W.; Grevemeyer, I.; Ranero, C. R.; Booth-Rea, G.; Gallart, J.

    2010-12-01

    The Alboran basin is located in the western-most Mediterranean Sea and is surrounded by the Gibraltar-Betic and Rif orogenic arc. The sediment infill indicates that the most important phase of formation started in the early-to-mid-Miocene. Currently two conflicting models have been proposed for their formation: One model proposes contractive tectonics producing strike-slip faults and folds with sedimentation occurring in synclinal basins and in regions of subsidiary extension in transtensional fault segments. A second model proposes a driving slab roll back that caused contraction at the front of the arc and coeval overriding plate bending and extension and associated arc magmatism. However, this phase has been partially masked by late Miocene to present contractive structures, caused by the convergence of Africa and Iberia. In September 2006 a 250 km long seismic refraction and wide-angle profile was acquired coincident with the existing multi-channel seismic (MCS) ESCI-Alb2 line using the German research vessel Meteor. The source was an array of two 32 litres BOLT airguns. Shots were recorded on 24 ocean-bottom seismometer (OBS) and ocean-bottom hydrophone (OBH) stations. The profile runs roughly along the axis of the basin, circa 65 km off the coast of Morocco, north of the Alboran Ridge. It continues in an ENE direction to end north of Mostaghanem in Algeria. Using seismic tomography we mapped the crustal and upper mantle structure of the eastern Alboran Sea and the western most Algero-Balearic basin. The most eastern part of the profile indicates crust in the order of 5-5.5 km with a high gradient upper crust (Vp~3.5 to 6 km/s) and gentler lower crust gradient (Vp ~6 to 6.8 km/s), which we interpret as a velocity structure typical of oceanic crust. Towards the west, crust thickens to 11-13 km and crustal velocities tend to be lower than in the eastern domain. Mantle velocity is 7.6-7.7 km/s in the oceanic domain and <7.2-7.3 km/s under the eastern Alboran

  15. Introduced marine species in Croatian waters (Eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    M. PECAREVIC

    2013-03-01

    Full Text Available The Croatian part of the Adriatic Sea covers more than 35% of the total Croatian territory, which means that monitoring changes in marine ecosystems and the conservation of biodiversity are of great importance. Following global changes, Croatia is experiencing increasing problems due to the introduction of new species that include aliens (due to aquaculture activities and shipping and species from other Mediterranean subregions that are extending their geographic range. This work provides a checklist of introduced species in Croatian waters. A total of 113 species (15 phytoplankton, 16 zooplankton, 16 macroalgae, 44 zoobenthic and 22 fish species have been recorded in the eastern part of the Adriatic Sea, of which 61 species are alien and 52 introduced, due to climate change.

  16. Deep Nitrate Deficit Observed in the Highly Oxygenated East/Japan Sea and Its Possible Cause

    Directory of Open Access Journals (Sweden)

    Il-Nam Kim

    2012-01-01

    Full Text Available We present evidence of denitrification on the continental slopes of the Ulleung Basin (UB and the Eastern Japan Basin (EJB near the Tatar Strait (TtS in the East/Japan Sea (EJS, despite its high water column dissolved oxygen concentrations. Some nutrient concentration data deviate significantly from the fitted regression line of nitrate (N vs. phosphate (P in deep waters, indicating a loss of nitrate in the region. The EJS has a lower N/P ratio (ca. 12.4 below 300 dbar than a traditional Redfield ratio (16. The N/P ratio and oxygen concentration are substantially lower at several locations whose depths are close to the sediment-water interface, near TtS (500 - 1100 dbar and in UB (1100 - 2200 dbar. The decreased nitrate concentration is smaller than the expected nitrate level (a low N/P ratio of < 12.4, and a secondary nitrite peak near the bottom of these two regions: taken collectively, both indicate the presence of denitrification in the bottom layer. It is speculated that active re-mineralization and denitrification may occur simultaneously along the rich organic matter bottom layer on the slope environment. Denitrification rates are estimated at ~3 - 33 μmol N m-2 d-1. Current estimates do not support the previous idea of basin-wide denitrification in EJS, although the N/P ratio is low like in other hypoxic/anoxic seas. A better understanding of the denitrification process is necessary for predicting future changes of nitrogen cycle in the well-oxygenated EJS considering the decadal-scale physical and biogeochemical changes that have occurred.

  17. Nuclear risk reduction study. The effect of sea salt aerosols in the Japan sea coast facilities

    International Nuclear Information System (INIS)

    Nakayasu, Fumio

    2007-01-01

    All of 15 nuclear power plants in Fukui Prefecture are located in the Japan Sea Coast. Corrosion is strongly influenced by material and environmental factors. We installed the salt damage experimental yard at Awara sea coast in March, 2006. We are doing the open air test, sheltered test without filter and with filter. The carbon steel standard specimen were exposed under three kinds of test conditions mentioned above. The corrosivity of the open air test specimens was higher than it of Miyako Island, Okinawa. The corrosivity of carbon steel of winter was higher than it of summer. The measurement of chloride deposition rate was done by the dry gauze method. The correlation between chloride deposition rate and the average velocity of the wind was found. The correlation between chloride deposition rate and the average rainfall was a little complicate. It means the chloride deposition rate has maximum value at a certain rainfall amount. No other clear relation was found. (author)

  18. Historical Tsunami Records on Russian Island, the Sea of Japan

    Science.gov (United States)

    Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Arslanov, Kh. A.; Ivanova, E. D.; Ganzey, K. S.; Kharlamov, A. A.

    2018-03-01

    In this article, we provide data evidencing tsunamis on Russian Island over the last 700 years. Reconstructions are developed based on the analyses of peat bog sections on the coast of Spokoynaya Bay, including layers of tsunami sands. Ancient beach sands under peat were deposited during the final phase of transgression of the Medieval Warm Period. We used data on diatoms and benthic foraminifers to identify the marine origin of the sands. The grain size compositions of the tsunami deposits were used to determine the sources of material carried by the tsunamis. The chronology of historical tsunamis was determined based on the radiocarbon dating of the underlying organic deposits. There was a stated difference between the deposition environments during tsunamis and large storms during the Goni (2015) and Lionrock (2016) typhoons. Tsunami deposits from 1983 and 1993 were found in the upper part of the sections. The inundation of the 1993 tsunami did not exceed 20 m or a height of 0.5 m a.m.s.l. (0.3 above high tide). The more intensive tsunami of 1983 had a run-up of 0.65 m a.m.s.l. and penetrated inland from the shoreline up to 40 m. Sand layer of tsunami 1940 extend in land up to 50 m from the present shoreline. Evidence of six tsunamis was elicited from the peat bog sections, the deposits of which are located 60 m from the modern coastal line. The deposits of strong historic tsunamis in the Japan Sea region in 1833, 1741, 1614 (or 1644), 1448, the XIV-XV century and 1341 were also identified on Russian Island. Their run-ups and inundation distances were also determined. The strong historic tsunamis appeared to be more intensive than those of the XX century, and considering the sea level drop during the Little Ice Age, the inundation distances were as large as 250 m.

  19. The estimation of turnover time in the Japan Sea bottom water by 129I

    International Nuclear Information System (INIS)

    Suzuki, Takashi; Togawa, Orihiko; Minakawa, Masayuki

    2010-01-01

    It is well known that the Japan Sea is sensitive for the environment such a global warming. To understand the oceanic circulation in the Japan Sea, we estimated a turnover time and a potential formation rate of the Japan Sea bottom water (JSBW) using an oceanographic tracer of 129 I. The turnover time of JSBW was calculated based on the increased concentration during the nuclear era. The turnover time was estimated to be 180 - 210 years. The potential formation rate of JSBW is calculated based on the existence of the anthropogenic 129 I in the JSBW. The potential formation rate of JSBW is estimated to be (3.6-4.1) x 10 12 m 3 /y which is consistent with another estimation and is about quarter of that of the upper Japan Sea proper water. (author)

  20. The "OSHORO MARU" cruise 21 to the Southern Sea of Japan, January 1967 (NODC Accession 7101334)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and other data were collected using net, bottle casts, and other instruments from OSHORO MARU in the Sea of Japan. Data were collected from 11...

  1. Temporal and Spatial Variabilities of Japan Sea Surface Temperature and Atmospheric Forcings

    National Research Council Canada - National Science Library

    Chu, Peter C; Chen, Yuchun; Lu, Shihua

    1998-01-01

    ...) and surface air temperature (SAT) data during 1982-1994 and the National Center for Atmospheric Research surface wind stress curl data during 1982-1989 to investigate the Japan Sea SST temporal and spatial variabilities...

  2. Present status of marine environmental radioactivity survey in the sea of Japan

    International Nuclear Information System (INIS)

    Matsuoka, H.

    1994-01-01

    Science and Technology Agency has been conducting some Marine Environmental Radioactivity Surveys around Japan in cooperation with the relevant organizations (Maritime Safety Agency, Japan Meteorological Agency, Fishery Agency, National Institute of Radiological Sciences, Japan Marine Science and Technology Center, Japan Chemical Analysis Center and Marine Ecology Research Institute). Several artificial radionuclides have been detected but the main origin is supposed to be fall-out. The level trend of marine environmental radioactivity has no anomalies excepting the effect of Chernobyl Accident. The data summarized here are as follows. 1. Marine Environmental Survey of Fisheries near the Nuclear Power Stations, 2. Past Data of Marine Environmental Radioactivity around Japan (Apr. 1982 - Mar. 1991), 3. Marine Environmental Survey of the Sea of Japan (spring, 1993), 4. Marine Environmental Survey of the Sea of Japan (autumn, 1993). In addition, JAPAN-KOREA-RUSSIA JOINT EXPEDITION in the Sea of Japan will start in the middle of March. We are expecting to get valuable data through the EXPEDITION. (J.P.N.)

  3. Organic Matter Contents and Paleoproductivity Variation Within Late Pleistocene Japan Sea/East Sea Sediments: Results from IODP Expedition 346

    Science.gov (United States)

    Black, H. D.; Anderson, W. T., Jr.

    2017-12-01

    Inorganic and organic matter concentrations as well as the stable isotopes of nitrogen and organic carbon are presented for continuous sedimentary sequences collected during Integrated Ocean Drilling Program (IODP) Expedition 346 in the Japan Sea/East Sea in 2013. During major glacioeustatic sea level changes, the paleoceanographic conditions within the Japan Sea/East Sea widely vary due to the shallow, narrow straights connecting the sea to surrounding waters limiting an influx of oceanic currents. During glacial sea level low-stands the sea can be nearly isolated, creating a highly-stratified water column and hypoxic to anoxic bottom water conditions. Meanwhile during sea level high-stands, the Tsushima Warm Current (TWC) flows into the sea bringing warmer, nutrient-rich inputs, leading to vertical mixing and oxic conditions. This study aims to better understand the role of orbital cycling within the organic matter and stable isotope contents of these Late Pleistocene sediments. A total of 192 samples were analyzed each for %CaCO3, %TOC, δ13C, %N, and δ15N from two Expedition 346 sampling sites (U1426 and U1427) during the last 430,000 years and statistical analyses were completed using wavelet and time series analyses. Carbonate concentration ranges from 0-44.3%, total organic carbon 0.2 to 6.4%, δ13C -25.8 to -19.6‰, %N 0.04 to 0.4%, and δ15N 3.8 to 13.1‰. These results are well correlated with b* color values of the sediment and generally show increased productivity during interglacial periods, likely through increased vertical mixing and deepwater ventilation, when compared to glacial periods within the Japan Sea/East Sea when the sea may be partially isolated.

  4. 2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan

    Science.gov (United States)

    Ando, Y.; Ogi, M.; Tachibana, Y.

    2013-12-01

    reference, the conventional AO index is shown by the gray line. (b) a 5-day running mean WP index, (c) area-averaged Surface Air Temperature anomalies in Japan, (d) Air Temperature anomalies, (e) heat flux anomalies, and (f) Sea Surface Temperature anomalies. The boxed area on the Sea of Japan indicates the area in which the (d)-(f) indexes were calculated.

  5. Autumn CO2 chemistry in the Japan Sea and the impact of discharges from the Changjiang River

    Science.gov (United States)

    Kosugi, Naohiro; Sasano, Daisuke; Ishii, Masao; Enyo, Kazutaka; Saito, Shu

    2016-08-01

    We made comprehensive surface water CO2 chemistry observations in the Japan Sea during each autumn from 2010 to 2014. The partial pressure of CO2 (pCO2) in surface water, 312-329 μatm, was 10-30 μatm lower in the Japan Sea than in the same latitude range of the western North Pacific adjacent to Japan. According to the sensitivity analysis of pCO2, the lower pCO2 in the Japan Sea was primarily attributable to a large seasonal decrease of pCO2 associated with strong cooling in autumn, particularly in the northern Japan Sea. In contrast, the lower pCO2 in relatively warm, freshwater in the southern Japan Sea was attributable to not only the thermodynamic effect of the temperature changes but also high total alkalinity. This alkalinity had its origin in Changjiang River and was transported by Changjiang diluted water (CDW) which seasonally runs into the Japan Sea from the East China Sea. The input of total alkalinity through CDW also elevated the saturation state of calcium carbonate minerals and mitigated the effects of anthropogenic ocean acidification, at least during autumn. These biogeochemical impacts of CDW in the Japan Sea last until November, although the inflow from the East China Sea to the Japan Sea almost ceases by the end of September. The long duration of the high saturation state of calcium carbonate benefits calcareous marine organisms.

  6. Temperature and water density data from meteorological sensors in the Sea of Japan and Yellow Sea from KODC, 01 January 1923 to 31 December 2001 (NODC Accession 0000914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and water density data were collected using meteorological sensors from coastal stations in the Sea of Japan and Yellow Sea. Data were submitted by the...

  7. Bacterial abundance and production in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Raghukumar, S.; Gauns, M.

    Seasonal and spatial variations in bacterial and picoplankton abundances and bacterial production (thymidine incorporation rates) were determined in the water column up to 150 m in several stations in the central and eastern Arabian Sea. Higher...

  8. Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoons

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Haridas, P.; Nair, K.K.C.; Gopalakrishnan, T.C.; Shiney, P.; Madhupratap, M.

    The vertical distribution of mesozooplankton in the central and eastern Arabian Sea was investigated during the winter monsoon in 1995. Samples were analysed from discrete depth zones defined according to oxygen and temperature profiles of the water...

  9. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (Oceanography data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  10. Coastal and Terminus History of the Eastern Amundsen Sea Embayment, West Antarctica, 1972 - 2011, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a coastline history of the eastern Amundsen Sea Embayment and terminus histories of its outlet glaciers derived from those coastlines. These...

  11. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  12. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (TSG-thermosalinigraph data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  13. AFSC/ABL: Eastern Bering Sea (EMA-BASIS) Zooplankton data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  14. Directionality and spread of shallow water waves along the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Anoop, T.R.

    The directional characteristics of shallow water waves are described based on measured data during 2011 at two locations spaced at 350 km along the eastern Arabian Sea. Study shows that, for high swells (significant wave height > 1 m) approaching...

  15. Nutrient biogeochemistry of the eastern Arabian Sea during the southwest monsoon retreat

    Digital Repository Service at National Institute of Oceanography (India)

    George, R; Muraleedharan, K.R; Martin, G.D.; Sabu, P.; Gerson, V.J.; Dineshkumar, P.K.; Nair, S.M.; Chandramohanakumar, N.; Nair, K.K.C

    Hydrography of the eastern Arabian Sea and associated chemical and biological responses were studied during the withdrawal phase of summer monsoon 2003. The shelf region off the southwest coast of India (10 degrees N-15 degrees N) continued...

  16. Skate Bathyraja spp. egg predation in the eastern Bering Sea.

    Science.gov (United States)

    Hoff, G R

    2009-01-01

    Predation on skate eggs by snails was examined for three skate species at seven nursery sites in three regions (north, middle and south) of the eastern Bering Sea. Mean predation levels were 6.46% for the Alaska skate Bathyraja parmifera, 2.65% for the Aleutian skate Bathyraja aleutica and 22.25% for the Bering skate Bathyraja interrupta. Predation levels were significantly higher at the middle and north sites than the south sites for all species combined. Predation levels decreased with increasing egg-case densities at all nursery sites, and the highest predation levels occurred where egg-case densities were very low. Predated egg-case density increased with increasing snail densities across all nursery sites examined. The Oregon triton Fusitriton oregonensis was the most abundant snail species at all nursery sites and displayed ability to drill holes in the egg case of B. parmifera. Holes left by predatory snails in egg cases of B. parmifera were significantly larger, and of different shape at the middle site compared to the south site. Holes in B. parmifera were also significantly larger than those in egg cases of B. interrupta across all sites examined. Egg cases of B. aleutica possess surface spines that cover the egg case and may inhibit predation by snails at a greater rate than that of the B. parmifera and B. interrupta, which have a smoother egg-case surface.

  17. Corals, Canyons, and Conservation: Science Based Fisheries Management Decisions in the Eastern Bering Sea

    Directory of Open Access Journals (Sweden)

    Steve A. MacLean

    2017-05-01

    Full Text Available When making science matter for conservation, marine conservation practitioners, and managers must be prepared to make the appropriate decision based on the results of the best available science used to inform it. For nearly a decade, many stakeholders encouraged the North Pacific Fishery Management Council to enact protections for deep-sea corals in several canyons in the Eastern Bering Sea slope. In 2014, at the request of the Council, the National Marine Fisheries Service, Alaska Fisheries Science Center conducted a strip-transect survey along the Eastern Bering Sea slope to validate the results of a model predicting the occurrence of deep-sea coral habitat. More than 250,000 photos were analyzed to estimate coral, sponge, and sea whip abundance, distribution, height, and vulnerability to anthropogenic damage. The results of the survey confirmed that coral habitat and occurrence was concentrated around Pribilof Canyon and the adjacent slope. The results also confirmed that the densities of corals in the Eastern Bering Sea were low, even where they occurred. After reviewing the best available scientific information, the Council concluded that there is no scientific evidence to suggest that deep-sea corals in the Eastern Bering Sea slope or canyons are at risk from commercial fisheries under the current management structure, and that special protections for deep-sea corals were not warranted.

  18. Hydrography of the eastern Arabian Sea during summer monsoon ...

    Indian Academy of Sciences (India)

    These barrier layers were advected away from the source region by the West India Coastal Current and had no discernible effect on the sea surface temperature.The three high-salinity water masses,the Arabian Sea High Salinity Water (ASHSW),Persian Gulf Water (PGW),and Red Sea Water (RSW),and the Arabian Sea ...

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

    Science.gov (United States)

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

    2016-04-01

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

  20. 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.

    The effect of salinity on the formation of the barrier layer (BL) in the South-Eastern Arabian Sea (SEAS) is investigated using an ocean general circulation model. In accordance with previous studies, the runoff distribution and the India-Sri Lanka...

  1. 77 FR 23209 - Endangered and Threatened Species; Proposed Delisting of Eastern DPS of Steller Sea Lions

    Science.gov (United States)

    2012-04-18

    .... Dictionary definitions of `significant' provide a number of possible meanings; one of the most prominent is... to the eastern Steller sea lion population from potential food web alteration, direct physiological... distribution and abundance of Steller sea lion prey assemblages. If the underlying food webs are affected by...

  2. Migration of Tundra Swans (Cygnus columbianus) Wintering in Japan Using Satellite Tracking: Identification of the Eastern Palearctic Flyway.

    Science.gov (United States)

    Chen, Wenbo; Doko, Tomoko; Fujita, Go; Hijikata, Naoya; Tokita, Ken-Ichi; Uchida, Kiyoshi; Konishi, Kan; Hiraoka, Emiko; Higuchi, Hiroyoshi

    2016-02-01

    Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in 2009-2012 and satellite-tracked. A new method called the "MATCHED (Migratory Analytical Time Change Easy Detection) method" was developed. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5.5 days and 6.8 days for the spring and autumn migrations, respectively. The number of stopover sites was 3.0 and 2.5 for the spring and autumn migrations, respectively. The mean travel distances for the spring and autumn migrations were 6471 and 6331 km, respectively. Seven migration routes passing Sakhalin, the Amur River, and/or Kamchatka were identified. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. The migration patterns of these two swan species that winter in Japan confirm the importance of the Amur River, Udyl' Lake, Shchastya Bay, Aniva Bay, zaliv Chayvo Lake, zal Piltun Lake, zaliv Baykal Lake, Kolyma River, Buyunda River, Sen-kyuyel' Lake, and northern coastal areas of the Sea of Okhotsk.

  3. Drift in salinity data from Argo profiling floats in the Sea of Japan

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Bajish, C.C; Behera, S.; Gopalakrishna, V.V.

    . The efficiency of this new method in finding out possible drift in the Argo salinity is demonstrated in the Sea of Japan (SOJ) by using the "near-linear" subsurface salinity structure of the SOJ. The new method is based on the time–space decorrelation scale...

  4. Investigation of environmental radioactivity in waste dumping areas of the far eastern seas. JAERI's activities in the 1st Japanese-Korean-Russian joint expedition 1994

    International Nuclear Information System (INIS)

    Amano, Hikaru; Matsunaga, Takeshi; Yabuuchi, Noriaki.

    1996-10-01

    Large quantities of radioactive waste have been dumped in the Far Eastern Sea by the former USSR and Russia. In order to survey marine radioactive contamination in the Far Eastern Sea, the first Japanese-Korean-Russian joint expedition was conducted according to the governmental agreement. The joint expedition was conducted at the areas of the Russian radioactive waste dumping site from March 18 1994 to April 6, 1994. JAERI participated in this expedition according to the request from STA Japan, and conducted mainly on-board measurement of marine radioactivities. The results showed that the radionuclides concentrations in seawater and seabed sediment samples from the study site were not different from those in the western North Pacific. This report summarises JAERI's activities in the expedition. Final report by Japanese-Korean-Russian government and IAEA is annexed. (author)

  5. Seismological structures of the subducted Philippine Sea plate and the overriding SW Japan arc, - Reinterpretation of the wide-angle reflection data in the Kii Peninsula, SW Japan -

    Science.gov (United States)

    Iwasaki, Takaya; Kurashimo, Eiji; Abe, Susumu; Yokota, Ken; Iidaka, Takashi; Katao, Hiroshi; Higashinaka, Motonori; Nakanishi, Ayako; Kaneda, Yoshiyuki

    2017-04-01

    Our recent reinterpretation for seismic refraction/wide-angle reflection data in eastern Kii Peninsula, SW Japan, provided new structural information on the uppermost part of the subducted Philippine Sea (PHS) plate and overriding the SW Japan arc, including the landward reflectivity variation in the vicinity of the plate boundary and the large scale structural change within the SW Japan arc. The Kii peninsula is located in the eastern part of the well-known subduction zone along the Nankai trough where offshore M8-class megathrust earthquakes repeatedly occur. The plate boundary beneath this Peninsula is in the stable or conditionally stable regime except for its southernmost tip, which corresponds to the northwestern end of the rupture area at the last event (1944 Tonankai earthquake (M7.9)). The surface geology of the overriding SW Japan arc is divided to two parts by the E-W trending Median Tectonic Line (MTL), the most prominent tectonic boundary in SW Japan. South of the MTL, Cretaceous-Jurassic accretionary complexes are exposed, whose northernmost unit consists of high P-T metamorphic rocks (the Sanbagawa metamorphic belt (SMB)). The region north of the MTL is occupied by older accretionary complexes, partly suffered from the Cretaceous magmatic intrusions. Our seismic data from five dynamite shots were acquired in 2006 along 80-km line almost perpendicular to the Nankai trough. The structure of the SW Japan arc was obtained both from intensive wide-angle reflection analysis and advanced reflection processing by seismic interferometry technique. The former analysis delineated clear structural change in the uppermost crust across the MTL. In the latter processing, we retrieved virtual shot records at 512 receiver points from free-surface backscattered waves by the deconvolution interferometry. The subsequent CRS (Common Reflection Surface)/MDRS (Multi-Dip Reflection Surfaces) methods provided an enhanced image within the island arc, including a northward

  6. Deep-Sea Phylogeographic Structure Shaped by Paleoenvironmental Changes and Ongoing Ocean Currents Around the Sea of Japan in a Crangonid Shrimp, Argis lar.

    Science.gov (United States)

    Fujita, Junta; Drumm, David T; Iguchi, Akira; Ueda, Yuji; Yamashita, Yuho; Ito, Masaki; Tominaga, Osamu; Kai, Yoshiaki; Ueno, Masahiro; Yamashita, Yoh

    2017-10-01

    The deep-sea crangonid shrimp, Argis lar, is a highly abundant species from the northern Pacific Ocean. We investigated its phylogeographic and demographic structure across the species' extensive range, using mitochondrial DNA sequence variation to evaluate the impact of deep-sea paleoenvironmental dynamics in the Sea of Japan on population histories. The haplotype network detected three distinct lineages with allopatric isolation, which roughly corresponded to the Sea of Japan (Lineage A), the northwestern Pacific off the Japanese Archipelago (Lineage B), and the Bering Sea/Gulf of Alaska (Lineage C). Lineage A showed relatively low haplotype and nucleotide diversity, a significantly negative value of Tajima's D, and a star-shaped network, suggesting that anoxic bottom-water in the Sea of Japan over the last glacial period may have brought about a reduction in the Sea of Japan population. Furthermore, unexpectedly, the distributions of Lineage A and B were closely related to the pathways of the two ocean currents, especially along the Sanriku Coast. This result indicated that A. lar could disperse across shallow straits through the ocean current, despite their deep-sea adult habitat. Bayesian inference of divergence time revealed that A. lar separated into three lineages approximately 1 million years before present (BP) in the Pleistocene, and then had been influenced by deep-sea paleoenvironmental change in the Sea of Japan during the last glacial period, followed by a more recent larval dispersal with the ocean current since ca. 6 kilo years BP.

  7. Current status of sea transport of nuclear fuel materials and LLW in Japan

    International Nuclear Information System (INIS)

    Kitagawa, Hiroshi; Akiyama, Hideo

    2000-01-01

    Along with the basic policy of the nuclear fuel cycle of Japan, many fuel cycle facilities have been already constructed in Rokkasho-Mura, Aomori prefecture, such as the uranium enrichment plant, the low level waste disposal center and the receiving pool of the spent nuclear fuels for reprocessing. These facilities belong to the Japan Nuclear Fuel Limited. (JNFL). Domestic sea transport of the spent nuclear fuels (SF) has been carried out since 1977 to the Tokai Reprocessing Plant, and the first sea transport of the SF to the fuel cycle facility in Rokkasho-Mura was done in Oct, 1998 using a new exclusive ship 'Rokuei-Maru'. Sea transport of the low level radioactive wastes (LLW) has been carried out since 1992 to the Rokkasho LLW Disposal Center, and about 130,000 LLW drams were transported from the nuclear power plant sites. These sea transport have demonstrated the safety of the transport of the nuclear fuel cycle materials. It is hoped that the safe sea transport of the nuclear fuel materials will contribute to the more progress of the nuclear fuel cycle activities of Japan. (author)

  8. Sea Urchin Embryogenesis as Bioindicators of Marine Pollution in Impact Areas of the Sea of Japan/East Sea and the Sea of Okhotsk.

    Science.gov (United States)

    Lukyanova, Olga N; Zhuravel, Elena V; Chulchekov, Denis N; Mazur, Andrey A

    2017-08-01

    The embryogenesis of the sea urchin sand dollar Scaphechinus mirabilis was used as bioindicators of seawater quality from the impact areas of the Sea of Japan/East Sea (Peter the Great Bay) and the Sea of Okhotsk (northwestern shelf of Sakhalin Island and western shelf of Kamchatka Peninsula). Fertilization membrane formation, first cleavage, blastula formation, gastrulation, and 2-armed and 4-armed pluteus formation have been analyzed and a number of abnormalities were calculated. Number of embryogenesis anomalies in sand dollar larvae exposed to sea water from different stations in Peter the Great Bay corresponds to pollution level at each area. The Sea of Okhotsk is the main fishing area for Russia. Anthropogenic impact on the marine ecosystem is caused by fishing and transport vessels mainly. But two shelf areas are considered as "hot spots" due to oil and gas drilling. Offshore oil exploitation on the northeastern Sakhalin Island has been started and at present time oil is being drill on oil-extracting platforms continuously. Significant reserves of hydrocarbons are prospected on western Kamchatka shelf, and exploitation drilling in this area was intensified in 2014. A higher number of abnormalities at gastrula and pluteus stages (19-36%) were detected for the stations around oil platforms near Sakhalin Island. On the western Kamchatka shelf number of abnormalities was 7-21%. Such anomalies as exogastrula, incomplete development of pairs of arms were not observed at all; only the delay of development was registered. Eggs, embryos, and larvae of sea urchins are the suitable bioindicators of early disturbances caused by marine pollution in impact ecosystems.

  9. Slip Inversion Along Inner Fore-Arc Faults, Eastern Tohoku, Japan

    Science.gov (United States)

    Regalla, Christine; Fisher, Donald M.; Kirby, Eric; Oakley, David; Taylor, Stephanie

    2017-11-01

    The kinematics of deformation in the overriding plate of convergent margins may vary across timescales ranging from a single seismic cycle to many millions of years. In Northeast Japan, a network of active faults has accommodated contraction across the arc since the Pliocene, but several faults located along the inner fore arc experienced extensional aftershocks following the 2011 Tohoku-oki earthquake, opposite that predicted from the geologic record. This observation suggests that fore-arc faults may be favorable for stress triggering and slip inversion, but the geometry and deformation history of these fault systems are poorly constrained. Here we document the Neogene kinematics and subsurface geometry of three prominent fore-arc faults in Tohoku, Japan. Geologic mapping and dating of growth strata provide evidence for a 5.6-2.2 Ma initiation of Plio-Quaternary contraction along the Oritsume, Noheji, and Futaba Faults and an earlier phase of Miocene extension from 25 to 15 Ma along the Oritsume and Futaba Faults associated with the opening of the Sea of Japan. Kinematic modeling indicates that these faults have listric geometries, with ramps that dip 40-65°W and sole into subhorizontal detachments at 6-10 km depth. These fault systems can experience both normal and thrust sense slip if they are mechanically weak relative to the surrounding crust. We suggest that the inversion history of Northeast Japan primed the fore arc with a network of weak faults mechanically and geometrically favorable for slip inversion over geologic timescales and in response to secular variations in stress state associated with the megathrust seismic cycle.

  10. Phylogeography of Phytophagous Weevils and Plant Species in Broadleaved Evergreen Forests: A Congruent Genetic Gap between Western and Eastern Parts of Japan

    Directory of Open Access Journals (Sweden)

    Kyoko Aoki

    2011-04-01

    Full Text Available The Quaternary climate cycles played an important role in shaping the distribution of biodiversity among current populations, even in warm-temperate zones, where land was not covered by ice sheets. We focused on the Castanopsis-type broadleaved evergreen forest community in Japan, which characterizes the biodiversity and endemism of the warm-temperate zone. A comparison of the phylogeographic patterns of three types of phytophagous weevils associated with Castanopsis (a host-specific seed predator, a generalist seed predator, and a host-specific leaf miner and several other plant species inhabiting the forests revealed largely congruent patterns of genetic differentiation between western and eastern parts of the main islands of Japan. A genetic gap was detected in the Kii Peninsula to Chugoku-Shikoku region, around the Seto Inland Sea. The patterns of western-eastern differentiation suggest past fragmentation of broadleaved evergreen forests into at least two separate refugia consisting of the southern parts of Kyushu to Shikoku and of Kii to Boso Peninsula. Moreover, the congruent phylogeographic patterns observed in Castanopsis and the phytophagous insect species imply that the plant-herbivore relationship has been largely maintained since the last glacial periods. These results reinforce the robustness of the deduced glacial and postglacial histories of Castanopsis-associated organisms.

  11. Distribution patterns of salinity and 222Rn in Yatsushiro Inland Sea, Kyushu, Japan

    Directory of Open Access Journals (Sweden)

    Y. Nikpeyman

    2015-03-01

    Full Text Available Submarine Groundwater Discharge (SGD, as a way through which solutes and nutrients travel from terrestrial areas towards coastal areas, is part of the hydrological cycle. Various methods are used to locate SGD at different scales. Among them, 222Rn has been developed with the viewpoint of accurate local estimations of SGD points indirectly. This research aims to identify SGD areas in the Yatsushiro Sea, southwest Japan, using the 222Rn method, while considering rivers with high 222Rn concentration in the study area. The area is an inland sea with high tidal fluctuations and there is a large contribution between the sea and groundwater, which are greatly affected by rivers. A multi-detector 222Rn survey has been carried out simultaneously with sea water electrical conductivity (EC and temperature. In addition, several river grab samples were analysed for 222Rn concentration. Considering the sea water radon distribution and river characteristics, several points were selected for future SGD volume estimations.

  12. Re-initiation of bottom water formation in the East Sea (Japan Sea) in a warming world.

    Science.gov (United States)

    Yoon, Seung-Tae; Chang, Kyung-Il; Nam, SungHyun; Rho, TaeKeun; Kang, Dong-Jin; Lee, Tongsup; Park, Kyung-Ae; Lobanov, Vyacheslav; Kaplunenko, Dmitry; Tishchenko, Pavel; Kim, Kyung-Ryul

    2018-01-25

    The East Sea (Japan Sea), a small marginal sea in the northwestern Pacific, is ventilated deeply down to the bottom and sensitive to changing surface conditions. Addressing the response of this marginal sea to the hydrological cycle and atmospheric forcing would be helpful for better understanding present and future environmental changes in oceans at the global and regional scales. Here, we present an analysis of observations revealing a slowdown of the long-term deepening in water boundaries associated with changes of water formation rate. Our results indicate that bottom (central) water formation has been enhanced (reduced) with more (less) oxygen supply to the bottom (central) layer since the 2000s. This paper presents a new projection that allows a three-layered deep structure, which retains bottom water, at least until 2040, contrasting previous results. This projection considers recent increase of slope convections mainly due to the salt supply via air-sea freshwater exchange and sea ice formation and decrease of open-ocean convections evidenced by reduced mixed layer depth in the northern East Sea, resulting in more bottom water and less central water formations. Such vigorous changes in water formation and ventilation provide certain implications on future climate changes.

  13. Methane hydrate reservoir model around the eastern Nankai trough area offshore Japan

    Energy Technology Data Exchange (ETDEWEB)

    Inamori, T.; Hayashi, M.; Kobayashi, T.; Shimoda, N.; Takano, O.; Takayama, T.; Fujii, T.; Saeki, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan). Dept. of Technology Research and Development

    2008-07-01

    This paper described a modelling study conducted to characterize gas hydrates in the eastern Nankai trough region near the coast of Japan. Two drilling campaigns were conducted in the region, and a total of 39 boreholes were drilled to obtain logging data. Data from exploratory wells drilled in the region were also presented. Methane hydrate-concentrated zones were delineated using seismic sequence analysis and 3-D seismic surveys. Methane hydrate-bearing sediments corresponded with turbidite sands using logging and coring data. A rock physics model was developed using data obtained from the analyses. The study showed that methane hydrate bearing-sediments near the eastern Nankai trough area are heterogenous and both vertically and horizontally complex, as the sediments were composed of turbidite sands with channel-levee and lobe systems. Sandy intervals had higher levels of methane hydrates than silty or muddy intervals. The reservoirs were divided into 3 distinct types: (1) low-saturation; (2) discontinuous high-saturation; and (3) continuous high-saturation. The reservoirs were delineated by selecting the bottom simulating reflector (BSM) as the top of the hydrate-bearing sediments for the turbidite channel-levee or lobe systems. The hydrate rock physics model was used to develop the matrix support model from the relationship between P and S wave velocities and methane hydrate saturation. 9 refs., 11 figs.

  14. The Response of the Aegean Sea (Eastern Mediterranean) to the Extreme 2016-2017 Winter

    Science.gov (United States)

    Velaoras, Dimitris; Papadopoulos, Vassilis P.; Kontoyiannis, Harilaos; Papageorgiou, Dimitra K.; Pavlidou, Alexandra

    2017-09-01

    The exceptionally cold December 2016 over the Aegean Sea—one of the most important dense water formation areas of the eastern Mediterranean Sea—resulted in winter heat loss comparable to the peak Eastern Mediterranean Transient winters (1992-1993). Hydrological data sampled in March/April 2017 showed that newly produced dense waters ventilated the North Aegean deep basins up to density horizons of σθ 29.35 kg/m3. The water column ventilation was unable to reach the bottom as the present upper thermohaline circulation of the eastern Mediterranean does not favor the salinity preconditioning of the Aegean Sea. In the southwest Aegean, the Myrtoan basin was ventilated by dense waters traceable farther south to the West Cretan Straits. Export of these masses from the Aegean Sea can potentially have a broader impact on the thermohaline circulation of the eastern Mediterranean.

  15. Assessment of metal element concentrations in mussel (M. Galloprovincialis) in Eastern Black Sea, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, U. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)], E-mail: berrenazli@yahoo.com; Damla, N.; Kobya, A.I. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey); Bulut, V.N. [Giresun University, Department of Chemistry, 28049 Giresun (Turkey); Duran, C. [Karadeniz Technical University, Department of Chemistry, 61080 Trabzon (Turkey); Dalgic, G. [Rize University, Faculty of Fisheries, 53100 Rize (Turkey); Bozaci, R. [Karadeniz Technical University, Department of Physics, 61080 Trabzon (Turkey)

    2008-12-30

    The main goal of this work is to determine the effects of pollution of copper, lead and zinc mines on the Eastern Black Sea. Metal and heavy metal concentrations in the Eastern Black Sea mussels were measured using Energy Dispersive X-ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectroscopy (FAAS). The analytical results showed that the tissue of mussel in Eastern Black Sea contains K, Ca, Fe, Cu, Zn, and Sr elements, and the shell of mussel contains Ca, Cu, Sr, and Ba elements. Due to the detection limit of EDXRF, the mussels were analyzed with FAAS for Cr, Mn, Ni, Cd and Pb elements. An ANOVA and Pearson correlation analyses were performed. The results showed although that the mean concentrations of Cu and Zn for the tissue of the mussels were markedly above the permissible levels of the Turkish regulations, Zn concentration is in the limits of the Food and Agriculture Organization (FAO)

  16. Trophodynamics of a deep-sea demersal fish assemblage from the bathyal eastern Ionian Sea (Mediterranean Sea)

    Science.gov (United States)

    Madurell, T.; Cartes, J. E.

    2005-11-01

    Daily food consumption of the eight dominant demersal fish species of the bathyal eastern Ionian Sea were determined from field data on four seasonal cruises (April 1999, July August 1999, November 1999 and February 2000). Daily ration (DR) estimates ranged from 0.198 to 4.273% WW/WW. Overall, DR estimates were independent of the model used, and they were comparable to the daily consumption of other deep-sea fauna (e.g. fish and crustaceans). Both sharks studied ( Galeus melastomus and Etmopterus spinax) exhibited the highest values of DRs, together with the macrourid Coelorhynchus coelorhynchus in August. Among osteichthyes, DR estimates were related (in a multi-linear regression model) to the nature of their diet (i.e. their trophic level deduced from δ15N isotopic composition, the mean number of prey and trophic diversity). Thus, species feeding at a lower trophic level, ingesting a large number of prey items and with a very diversified diet had higher DR than species from higher trophic level and feeding fewer prey items. By season, the DR of species feeding mainly on mesopelagic prey ( Hoplostethus mediterraneus and Helicolenus dactylopterus) were higher in summer, while DR for benthos/suprabenthos feeders (i.e. C. coelorhynchus and Nezumia sclerorhynchus) were higher in spring. Higher food consumption coincides with maximum food availability, both among mesopelagic feeders (higher availability of euphausiids, Pasiphaea sivado and Sergestes arcticus in summer) and among Macrouridae (higher suprabenthos densities in spring). In a tentative estimate the energy intake deduced from diet (i.e. mean energy value of food ingested) was constant in all seasons for each species studied. Results for the energy intake also indicate higher energy intake in the diet of mesopelagic feeders than in the diet of benthic feeders. Overall results are discussed in relation to the deep-sea ecosystem structure and functioning.

  17. Late Neogene paleoceanography of the Sea of Japan based upon diatoms

    Energy Technology Data Exchange (ETDEWEB)

    Burkle, L.H. (Lamont-Doherty Geological Observatory Palisades, NY (USA))

    1990-06-01

    The authors identified several time intervals apparent late Neogene stepwise paleoenvironmental change in the southern Sea of Japan. The paleoenvironment of the middle Pliocene and older sediments cannot be characterized because the diatom assemblage is made up of a near monospecific ooze (Coscinodiscus marginatus). The middle Pliocene, prior to 2.4 Ma but after the deposition of the C. marginatus ooze, is characterized by warm water diatoms while the late Pliocene (between approximately 2.4 my and the Pliocene/Pleistocene boundary) is characterized by cool water diatoms belonging to an upwelling assemblage. The Tsushima Strait became emergent at approximately 2.4 Ma owing to sea level drop caused by initiation of continental ice build-up on Greenland and by ongoing tectonic uplift across the southern part of Honshu. Diatoms deposited above the Pliocene/Pleistocene boundary suggest that the Tsushima Strait was again submergent and that a branch of the Kuroshio Current flowed into the Sea of Japan. The early Quaternary is characterized by variable preservation and abundance of diatoms with warm water species predominating. They observed changes in both diatom abundance and preservation in upper Quaternary sediments, probably reflecting changes in productivity induced by major glacial/interglacial oscillations. They found no evidence of the complete isolation of the Sea of Japan from the Pacific but their data do suggest, at least, constriction of the Tsushima Strait during maximum glacial episodes. The late Pliocene-Pleistocene interval is characterized by alternating intervals of laminated/homogenous sediments. There are some 30 laminated intervals within the last 300 kyr suggesting that this signal may be the second harmonic of precession. The laminated layers may reflect salinity changes in the southern Sea of Japan.

  18. Ongoing decline of shark populations in the Eastern Red Sea

    KAUST Repository

    Spaet, Julia L.Y.

    2016-06-30

    Information on the abundance and diversity of Red Sea elasmobranchs is notoriously scarce, even though sharks are among the most profitable fisheries of the region. Effective conservation would ideally entail baselines on pristine conditions, yet no such data is available for the Red Sea. To collect distribution and abundance data on Red Sea elasmobranchs, we conducted a dedicated longline and Baited Remote Underwater Video system (BRUVs) sampling program along the entire Red Sea coast of Saudi Arabia over the course of two years. Both survey techniques were opportunistically employed at central and southern Saudi Arabian (SA) Red Sea reef systems. In addition, BRUVs were employed in the northern SA Red Sea and at selected reef systems in Sudan. Shark catch per unit effort (CPUE) data for BRUVs and longline surveys were compared to published data from non-Red Sea reef systems. This comparison revealed CPUE estimates several orders of magnitude lower for both survey methods in the SA Red Sea compared to other reef systems around the world. Catch per unit effort values of BRUVs on Sudanese reefs on the contrary were within the range of estimates from various locations where sharks are considered common. We argue that decades of heavy fishing pressure on Red Sea marine resources has significantly altered the community structure of SA Red Sea reefs. There is an urgent need to establish effective management strategies for species of highest conservation concern. Our results have the potential to be used as a baseline, if such management strategies were to be established. © 2016 Elsevier Ltd

  19. Borniopsis mortoni sp. n. (Heterodonta, Galeommatoidea, Galeommatidae sensu lato, a new bivalve commensal with a synaptid sea cucumber from Japan

    Directory of Open Access Journals (Sweden)

    Ryutaro Goto

    2016-09-01

    Full Text Available The Galeommatoidea is a bivalve superfamily that exhibits high species diversity in shallow waters. Many members of this superfamily are associated commensally with burrowing marine invertebrates in benthic sediments. The genus Borniopsis is known only from eastern Asia and exhibits high host diversity (e.g., mantis shrimps, crabs, holothurians, sipunculans and echiurans. A new species, Borniopsis mortoni sp. n., is described from mud flats at the mouth of the Souzu River, southwestern Shikoku Island, Japan. This species has elongate-ovate shells covered by a tan to dark brown periostracum, and lives attached by both its foot and byssal threads to the body surface of the synaptid sea cucumber Patinapta ooplax. Several individuals of B. mortoni are often found on the same host, but sometimes more than 10 individuals can occur together. Borniopsis mortoni is one of the smallest species in this genus. Probably, its small body size is an adaptation to the mode of life in a narrow host burrow. Until now, only two other Borniopsis species were known to have commensal associations with synaptids. Thus, this is the third example of a synaptid-associated species from this genus. In addition, we briefly review the galeommatoideans commensal with apodid sea cucumbers.

  20. Phylogeography of the sandy beach amphipod Haustorioides japonicus along the Sea of Japan: Paleogeographical signatures of cryptic regional divergences

    Science.gov (United States)

    Takada, Yoshitake; Sakuma, Kay; Fujii, Tetsuo; Kojima, Shigeaki

    2018-01-01

    Recent findings of genetic breaks within apparently continuous marine populations challenge the traditional vicariance paradigm in population genetics. Such "invisible" boundaries are sometimes associated with potential geographic barriers that have forced divergence of an ancestral population, habitat discontinuities, biogeographic disjunctions due to environmental gradients, or a combination of these factors. To explore the factors that influence the genetic population structure of apparently continuous populations along the Sea of Japan, the sandy beach amphipod Haustorioides japonicus was examined. We sampled a total of 300 individuals of H. japonicus from the coast of Japan, and obtained partial sequences of the mitochondrial COI gene. The sequences from 19 local populations were clustered into five groups (Northwestern Pacific, Northern, Central, Southern Sea of Japan, and East China Sea) based on a spatial genetic mixture analysis and a minimum-spanning network. AMOVA and pairwise Fst tests further supported the significant divergence of the five groups. Phylogenetic analysis revealed the relationship among the haplotypes of H. japonicus and outgroups, which inferred the northward range expansion of the species. A relaxed molecular-clock Bayesian analysis inferred the early-to middle-Pleistocene divergence of the populations. Among the five clusters, the Central Sea of Japan showed the highest values for genetic diversity indices indicating the existence of a relatively stable and large population there. The hypothesis is also supported by Bayesian Skyline Plots that showed sudden population expansion for all the clusters except for Central Sea of Japan. The present study shows genetic boundaries between the Sea of Japan and the neighboring seas, probably due to geographic isolation during the Pleistocene glacial periods. We further found divergence between the populations along the apparently continuous coast of the Sea of Japan. Historical changes in the

  1. Food and feeding ecology of emperor penguins in the eastern Weddell Sea

    OpenAIRE

    Klages, Norbert

    1989-01-01

    The diet of the emperor penguin Aptenodytes forsteri in the eastern Weddell Sea, Antarctica was studied during October and November 1986 by stomach content analysis. Emperor penguins fed mainly on Antarctic krill Euphausia superba, Antarctic silverfish Pleuragramma antarcticum and squid Psychroteuthis glacialis. Benthic prey was not found. The prey composition suggests two different feeding strategies, shallow dives exploring the rugged underside of sea ice where krill is taken, and deep dive...

  2. Japan.

    Science.gov (United States)

    Geiger, Rita; And Others

    The document offers practical and motivating techniques for studying Japan. Dedicated to promoting global awareness, separate sections discuss Japan's geography, history, culture, education, government, economics, energy, transportation, and communication. Each section presents a topical overview; suggested classroom activities; and easily…

  3. Acoustic profiling and surface imaging of the coastal area near the subduction zone: the eastern coastal area of Boso Peninsula, Central Japan.

    Science.gov (United States)

    Furuyama, S.; Sato, T.

    2016-12-01

    The plate motion of the Philippine Sea plate and the Pacific plate influences geology of coastal area in the Pacific side in Japan and sometime causes extensive damage of human activity, such as the Great East Japan Earthquake. It is important to understand the geological structures in a coastal area for disaster prevention. Especially, rapid equipment of geoinformations is highly demanded in the Kanto region where covers capital Tokyo area. Geological Survey of Japan investigated the eastern coastal area in Boso Peninsula, eastern part of the Kanto region, Japan within two years from 2014 to 2015. We obtained seismic sections of ca. 1100 km in total length with a boomer and multi-channel streamer (24 channel with 3.125 m spacing) and report the geological significance of the subsurface structures. The survey area is divided into the northern part of Kujukuri area, the southern part of Kujukuri area, the coastal part of Kujukuri area based on topography and geological structures. In these Kujukuri areas, two strata that show distinct stratification bounded by distinct unconformity distribute and we define them as the Kujukuri A Unit and the Kujukuri B Unit, in ascending order. The lower sequence has some folds and normal faults. These folds that deformed the Kujukuri B Unit extend toward north-northeast in the northern part of Kujukuri area. They contributed to development of wide shelf distributed in this area. In the southern part of Kujukuri area, a lot of faults deformed the Kujukuri B Unit and some of them displaced the Kujukuri A Unit over 10 msec (two way travel). Normal faults developed in the Kujukuri B Unit over 10 msec made grabens and half grabens in the coastal part of Kujukuri area and these grabens and half grabens could make the lowland in the Kujukuri coastal area. The combination of these geological structures identified in the Kujukuri areas could reflect the transition of stress field associated with the subduction of the Philippine Sea plate

  4. Deep Sea Pockmark Environments in the eastern Mediterranean

    NARCIS (Netherlands)

    Dimitrov, L.; Woodside, J.M.

    2003-01-01

    A great number of circular to isometric depressions have been observed on the deep water seafloor in the eastern Mediterranean by MAK-1 and ORETech deep-tow side-scan sonar during several TTR cruises of the UNESCO Floating University Program since 1993, and also by visual observations made during

  5. Aftereffects of Subduction-Zone Earthquakes: Potential Tsunami Hazards along the Japan Sea Coast.

    Science.gov (United States)

    Minoura, Koji; Sugawara, Daisuke; Yamanoi, Tohru; Yamada, Tsutomu

    2015-10-01

    The 2011 Tohoku-Oki Earthquake is a typical subduction-zone earthquake and is the 4th largest earthquake after the beginning of instrumental observation of earthquakes in the 19th century. In fact, the 2011 Tohoku-Oki Earthquake displaced the northeast Japan island arc horizontally and vertically. The displacement largely changed the tectonic situation of the arc from compressive to tensile. The 9th century in Japan was a period of natural hazards caused by frequent large-scale earthquakes. The aseismic tsunamis that inflicted damage on the Japan Sea coast in the 11th century were related to the occurrence of massive earthquakes that represented the final stage of a period of high seismic activity. Anti-compressive tectonics triggered by the subduction-zone earthquakes induced gravitational instability, which resulted in the generation of tsunamis caused by slope failing at the arc-back-arc boundary. The crustal displacement after the 2011 earthquake infers an increased risk of unexpected local tsunami flooding in the Japan Sea coastal areas.

  6. Geological modeling for methane hydrate reservoir characterization in the eastern Nankai Trough, offshore Japan

    Science.gov (United States)

    Tamaki, M.; Komatsu, Y.; Suzuki, K.; Takayama, T.; Fujii, T.

    2012-12-01

    The eastern Nankai trough, which is located offshore of central Japan, is considered as an attractive potential resource field of methane hydrates. Japan Oil, Gas and Metals National Corporation is planning to conduct a production test in early 2013 at the AT1 site in the north slope of Daini-Atsumi Knoll in the eastern Nankai Trough. The depositional environment of methane hydrate-bearing sediments around the production test site is a deep submarine-fan turbidite system, and it is considered that the reservoir properties should show lateral as well as vertical heterogeneity. Since the variations in the reservoir heterogeneity have an impact on the methane hydrate dissociation and gas production performance, precise geological models describing reservoir heterogeneity would be required for the evaluation of reservoir potentials. In preparation for the production test, 3 wells; two monitoring boreholes (AT1-MC and AT1-MT1) and a coring well (AT1-C), were newly acquired in 2012. In addition to a geotechnical hole drilling survey in 2011 (AT1-GT), totally log data from 2 wells and core data from 2 wells were obtained around the production test site. In this study, we conducted well correlations between AT1 and A1 wells drilled in 2003 and then, 3D geological models were updated including AT1 well data in order to refine hydrate reservoir characterization around the production test site. The results of the well correlations show that turbidite sand layers are characterized by good lateral continuity, and give significant information for the distribution morphology of sand-rich channel fills. We also reviewed previously conducted 3D geological models which consist of facies distributions and petrophysical properties distributions constructed from integration of 3D seismic data and a well data (A1 site) adopting a geostatistical approach. In order to test the practical validity of the previously generated models, cross-validation was conducted using AT1 well data. The

  7. 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,

  8. Differential growth of larval sprat Sprattus sprattus across a tidal front in the eastern North Sea

    DEFF Research Database (Denmark)

    Munk, Peter

    1993-01-01

    Spatial variations in abundance and growth of larval sprat Sprattus sprattus L. were examined across a tidal front in the eastern North Sea, off the west coast of Denmark. The aim of the study was to evaluate the potential advantage for sprat larvae of residing in the vicinity of a tidal front...

  9. Spatial and temporal variation of surface waves in shallow waters along the eastern Arabian Sea.

    Digital Repository Service at National Institute of Oceanography (India)

    Anoop, T.R.; SanilKumar, V.; Shanas, P.R.

    We studied the spatial and temporal variation of surface waves along the eastern Arabian Sea during 2011 and 2012. Measured directional wave data at two shallow water locations and re-analysis datasets (ERA-Interim) at 0.751 intervals at four...

  10. Shipboard measurements of nitrogen dioxide, nitrous acid, nitric acid and ozone in the Eastern Mediterranean Sea

    Czech Academy of Sciences Publication Activity Database

    Večeřa, Zbyněk; Mikuška, Pavel; Smolík, Jiří; Eleftheriadis, K.; Bryant, C.; Colbeck, I.; Lazaridis, M.

    2008-01-01

    Roč. 8, č. 1 (2008), s. 117-125 ISSN 1567-7230 Grant - others:5th FP Commission of the EC(XE) EVK2-CT-1999-0052 SUB-AERO Institutional research plan: CEZ:AV0Z40310501; CEZ:AV0Z40720504 Keywords : reactive nitrogen species * ozone * Eastern Mediterranean Sea Subject RIV: CB - Analytical Chemistry, Separation

  11. Carbonate and carbon fluctuations in the Eastern Arabian Sea over 140 ka: Implications on productivity changes?

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Naidu, P.D.; Haake, B.G.; Schiebel, R.

    ArabianSea,which by the presence of a well developed oxygen minimum zone (OMZ) with one of the largest marine volumes of suboxic ocean water today (Morrison et al., 1998). 3. Materialandmethods In the eastern Arabian Sea, two gravity cores SL-1 (19159.9 0 N/65140 0 E) and SL-4...,549–551. Morrison, J.M., Codispoti, L.A., Gaurin, S., Jones, B., Manghanani, V., Zheng, Z., 1998. Seasonal variation of II 52 (2005) 1981–1993 hydrographic and nutrient fields during the US JGOFS ARTICLE IN PRESS M.V.S. Guptha et al. / Deep-Sea Research II 52 (2005...

  12. Carbon budget in the eastern and central Arabian Sea: An Indian JGOFS synthesis

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Swathi, P.S.; DileepKumar, M.; PrasannaKumar, S.; Bhattathiri, P.M.A.; Madhupratap, M.; Ramaswamy, V.; Sarin, M.M.; Gauns, M.; Ramaiah, N.; Sardessai, S.; DeSousa, S.N.

    : Upper ocean processes: Kf"TIYORD.',': carbon, Arabian Sea, budgct. biogeochemistry, grazing, lGOFS Citation: Sarma, V. V. S. S.. el al .. Carhon budget in the eastern and central Arabian Sea: An Indian lGOFS synthesis, Global Biog(!ochem. (l'cles, J7... locations in the Arabian Sea. Shaded area represents depth <200 m. because of the upward pumping of nutrients by convection [Madhuprutap el al., 1996; Barber et 01., 2001], which results in deep mixed layers of 120 m in the northern Arabian Sca. de Sousa ct...

  13. Japan.

    Science.gov (United States)

    1989-02-01

    Japan consists of 3900 islands and lies off the east coast of Asia. Even though Japan is one of the most densely populated nations in the world, its growth rate has stabilized at .5%. 94% of all children go to senior high school and almost 90% finish. Responsibility for the sick, aged, and infirmed is changing from the family and private sector to government. Japan was founded in 600 BC and its 1st capital was in Nara (710-1867). The Portuguese, the 1st Westerners to make contact with Japan in 1542, opened trade which lasted until the mid 17th century. US Navy Commodore Matthew Perry forced Japan to reopen in 1854. Following wars with China and Russia in the late 1800s and early 1900s respectively, Japan took part in World Wars I and II. In between these wars Japan invaded Manchuria and China. The US dropped an atomic bomb on Hiroshima and Nagasaki and the Japanese surrendered in September, 1945 ending World War II (WWII). Following, WWII, the Allied Powers guided Japan's establishment as a nonthreatening nation and a democratic parliamentary government (a constitutional monarchy) with a limited defense force. Japan remains one of the most politically stable of all postwar democracies. The Liberal Democratic Party's Noboru Takeshita became prime minister in 1987. Japan has limited natural resources and only 19% of the land is arable. Japanese ingenuity and skill combine to produce one of the highest per hectare crop yields in the world. Japan is a major economic power, and its and the US economies are becoming more interdependent. Its exports, making up only 13% of the gross national product, mainly go to Canada and the US. Many in the US are concerned, however, with the trade deficit with Japan and are seeking ways to make trade more equitable. Japan wishes to maintain good relations with its Asian neighbors and other nations. The US and Japan enjoy a strong, productive relationship.

  14. Modes of sedimentary basin formation in the north-eastern Black Sea

    Science.gov (United States)

    Stephenson, Randell; Starostenko, Vitaly; Sydorenko, Grygoriy; Yegorova, Tamara

    2016-04-01

    The Greater Caucasus and Black Sea sedimentary basins developed in a Mesozoic back-arc setting, the former older than the latter (Jurassic v. Cretaceous). Compressional shortening of the former and accompanying ongoing development of marginal basin depocentres in the north-eastern Black Sea - which is closely tied to the formation of the Crimea-Greater Caucasus orogen - is a Cenozoic phenomenon, starting in the Eocene and proceeding until the present day. Recently, the sedimentary basin/crust/lithosphere geometry of the study area has been characterised across a range of scales using regional seismic reflection profiling, long-offset refraction/wide-angle reflection profiling and local earthquake tomography. These provide a new integrated image of the present-day crustal structure and sedimentary basin architecture of the northern margin of the eastern Black Sea, north across the Azov Sea and provide evidence of the deeper expression of sedimentary basins and the processes controlling the geometry of their inversion during the Cenozoic. It is inferred that the Greater Caucasus paleo-Basin, lying stratigraphically below the Black Sea and younger sedimentary successions, extends further to the west than previously known. This basin has significant thickness in the area between the Azov and Black seas and probably forms the deeper core of the Crimea-Caucasus inversion zone. The Crimea-Greater Caucasus orogenic belt is the expression of "basin inversion" of the Jurassic Greater Caucasus paleo-Basin, the degree of inversion of which varies along strike. The Greater Caucasus foredeep basins - Indolo-Kuban and Sorokin-Tuapse troughs -represent syn-inversional marginal troughs to the main inversion zone. The Shatsky Ridge - the northern flank of the main East Black Sea Basin - may also be mainly a syn-inversional structure, underlain by a blind thrust zone expressed as a northward dipping zone of seismicity on the northern margin of the eastern Black Sea.

  15. Unmanned aerial survey of fallen trees in a deciduous broadleaved forest in eastern Japan.

    Science.gov (United States)

    Inoue, Tomoharu; Nagai, Shin; Yamashita, Satoshi; Fadaei, Hadi; Ishii, Reiichiro; Okabe, Kimiko; Taki, Hisatomo; Honda, Yoshiaki; Kajiwara, Koji; Suzuki, Rikie

    2014-01-01

    Since fallen trees are a key factor in biodiversity and biogeochemical cycling, information about their spatial distribution is of use in determining species distribution and nutrient and carbon cycling in forest ecosystems. Ground-based surveys are both time consuming and labour intensive. Remote-sensing technology can reduce these costs. Here, we used high-spatial-resolution aerial photographs (0.5-1.0 cm per pixel) taken from an unmanned aerial vehicle (UAV) to survey fallen trees in a deciduous broadleaved forest in eastern Japan. In nine sub-plots we found a total of 44 fallen trees by ground survey. From the aerial photographs, we identified 80% to 90% of fallen trees that were >30 cm in diameter or >10 m in length, but missed many that were narrower or shorter. This failure may be due to the similarity of fallen trees to trunks and branches of standing trees or masking by standing trees. Views of the same point from different angles may improve the detection rate because they would provide more opportunity to detect fallen trees hidden by standing trees. Our results suggest that UAV surveys will make it possible to monitor the spatial and temporal variations in forest structure and function at lower cost.

  16. Women's participation in the medical profession: insights from experiences in Japan, Scandinavia, Russia, and Eastern Europe.

    Science.gov (United States)

    Ramakrishnan, Aditi; Sambuco, Dana; Jagsi, Reshma

    2014-11-01

    Although much literature has focused on the status of female physicians in the United States, limited English-language studies have examined the role of women in the medical profession elsewhere in the world. This article synthesizes evidence regarding the status of female physicians in three purposively selected regions outside the United States: Japan, Scandinavia, and Russia and Eastern Europe. These three regions markedly differ in the proportion of female physicians in the workforce, overall status of the medical profession, cultural views of gender roles, and workforce policies. Through a review of studies and articles published between 1992 and 2012 examining women's representation, status measures such as salary and leadership positions, and experiences of female physicians, the authors discuss potential relationships between the representation of female physicians, their status in medicine, and the overall status of the profession. The findings suggest that even when women constitute a high proportion of the physician workforce, they may continue to be underrepresented in positions of leadership and prestige. Evolving workforce policies, environments, and cultural views of gender roles appear to play a critical role in mediating the relationship between women's participation in the medical profession and their ability to rise to positions of influence within it. These insights are informative for the ongoing debates over the impact of the demographic shifts in the composition of the medical workforce in the United States.

  17. Seismomagnetic models for earthquakes in the eastern part of Izu Peninsula, Central Japan

    Directory of Open Access Journals (Sweden)

    Y. Ishikawa

    1997-06-01

    Full Text Available Seismomagnetic changes accompanied by four damaging earthquakes are explained by the piezomagnetic effect observed in the eastern part of Izu Peninsula, Central Japan. Most of the data were obtained by repeat surveys. Although these data suffered electric railway noise, significant magnetic changes were detected at points close to earthquake faults. Coseismic changes can be well interpreted by piezomagnetic models in the case of the 1978 Near Izu-Oshima (M 7.0 and the 1980 East Off Izu Peninsula (M 6.7 earthquakes. A large total intensity change up to 5 nT was observed at a survey point almost above the epicenter of the 1976 Kawazu (M 5.4 earthquake. This change is not explained by a single fault model; a 2-segment fault is suggested. Remarkable precursory and coseismic changes in the total force intensity were observed at KWZ station along with the 1978 Higashi-Izu (M 4.9 earthquake. KWZ station is located very close to a buried subsidiary fault of the M 7.0 Near Izu-Oshima earthquake, which moved aseismically at the time of the M 7.0 quake. The precursory magnetic change to the M 4.9 quake is ascribed to aseismic faulting of this buried fault, while the coseismic rebound to enlargement of the slipping surface at the time of M 4.9 quake. This implies that we observed the formation process of the earthquake nucleation zone via the magnetic field.

  18. Distribution of aerobic anoxygenic phototrophs in the Eastern Adriatic Sea

    Czech Academy of Sciences Publication Activity Database

    Šantić, D.; Šestanović, S.; Vrdoljak, A.; Šolić, M.; Kušpilić, G.; Ninčević Gladan, Ž.; Koblížek, Michal

    2017-01-01

    Roč. 130, SEP 2017 (2017), s. 134-141 ISSN 0141-1136 R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Aerobic anoxygenic phototrophs * Adriatic sea * Picoplankton Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.101, year: 2016

  19. ORGANOCHLORINE CONTAMINANTS IN SEA TURTLES FROM THE EASTERN PACIFIC

    Science.gov (United States)

    We measured organochlorine residues in three species of sea turtles from the Baja California peninsula, Mexico. Seventeen of 21 organochlorine pesticides analyzed were detected, with heptachlor epoxide and y-hexachlorocyclohexane the most prevalent in 14 (40%) and 11 (31%) of th...

  20. DDT residues in fishes from the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shailaja, M.S.; SenGupta, R.

    degrees E) were obtained from the commercial jetty within 2 h of landing while those from the open sea (16 degrees 30'N 69 degrees E-19 degrees 30'N 67 degrees E) such as Tylosurus sp. (longtom), Coryphaena hippurus (dolphin fish), Loligo sp. (squid...

  1. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1000 to 1500 A.D.

    Directory of Open Access Journals (Sweden)

    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1000 to 1500 A.D. in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea
    and the Italian coasts of the Adriatic Sea is the object of the
    present paper.

  2. Data from investigation on seismic Sea waves events in the Eastern Mediterranean from 1900 to 1980 A.D.

    Directory of Open Access Journals (Sweden)

    J. ANTONOPOULOS

    1980-06-01

    Full Text Available Tsunamis from 1900 to 1980 A.D. in the Eastern Mediterranean
    Sea between 31-44 N and 18-36 E excluding the Black Sea
    and the Italian coasts of the Adriatic Sea is the object of the
    present paper.

  3. Growth Rate Potential of Juvenile Sockeye Salmon in Warmer and Cooler Years on the Eastern Bering Sea Shelf

    Directory of Open Access Journals (Sweden)

    Edward V. Farley

    2009-01-01

    Full Text Available A spatially explicit bioenergetics model was used to predict juvenile sockeye salmon Oncorhynchus nerka growth rate potential (GRP on the eastern Bering Sea shelf during years with cooler and warmer spring sea surface temperatures (SSTs. Annual averages of juvenile sockeye salmon GRP were generally lower among years with cooler SSTs and generally higher in offshore than nearshore regions of the eastern Bering Sea shelf during years with warmer SSTs. Juvenile sockeye salmon distribution was significantly (P<.05 related to GRP and their prey densities were positively related to spring SST (P<.05. Juvenile sockeye salmon GRP was more sensitive to changes in prey density and observed SSTs during years when spring SSTs were warmer (2002, 2003, and 2005. Our results suggest that the pelagic productivity on the eastern Bering Sea shelf was higher during years with warmer spring SSTs and highlight the importance of bottom-up control on the eastern Bering Sea ecosystem.

  4. Seasonal Variations of Surface fCO2 and Sea-Air CO2 Fluxes in the Ulleung Basin of the East/Japan Sea

    Directory of Open Access Journals (Sweden)

    Sang-Hwa Choi

    2012-01-01

    Full Text Available Temperature, salinity, chlorophyll a, and surface CO2 fugacity (fCO2 were extensively investigated in the Ulleung Basin of the East/Japan Sea during four seasonal cruises. In spring, surface fCO2 showed large variations ranging from 260 to 356 £gatm, which were considerably lower than the atmospheric CO2 levels. Surface fCO2 was highest (316 to 409 £gatm in summer. The central part of the study area was undersaturated with respect to atmospheric CO2, while the coastal and easternmost regions were oversaturated. In autumn, the entire study area was fairly undersaturated with respect to atmospheric CO2. In winter, surface fCO2 ranged from 303 to 371 £gatm, similar to that in autumn, despite the much lower sea surface temperature. The seasonal variation in surface fCO2 could not be explained solely by seasonal changes in sea surface temperature and salinity. The vertical mixing, lateral transport, and sea-air CO2 exchange considerably influenced the seasonal variation in surface fCO2. The Ulleung Basin of the East/Japan Sea was a sink of atmospheric CO2 in spring, autumn, and winter, but a weak source of CO2 to the atmosphere in summer. The annual integrated sea-air CO2 flux in the Ulleung Basin of the East/Japan Sea was -2.47 ± 1.26 mol m-2 yr-1, quite similar to a previous estimate (-2.2 mol m-2 yr-1 in the south East/Japan Sea. This indicates that the Ulleung Basin of the East/Japan Sea acts as a strong sink of atmospheric CO2.

  5. Japan

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2013-01-01

    I 1500- og 1600-tallet dannedes tidligt moderne stater i Europa, men samtidig eksisterede der ligeså avancerede statsdannelser uden for Europa, bl.a. i Kina, Indien og Japan. I det følgende ser vi nærmere på dannelsen af den moderne stat i Japan. Hvorfor blev Japan aldrig en europæisk koloni......? Hvordan havde japanske magthavere igennem 300 år forberedt Japan og de mennesker, der boede på de japanske øer, til at kunne udvikle en nation, der skulle blive den stærkeste og rigeste i Asien i mere end 100 år? Hvem bestemte i Japan? Kejseren eller shogunen?...

  6. Flow Patterns in the Eastern Chukchi Sea: 2010-2015

    Science.gov (United States)

    Stabeno, Phyllis; Kachel, Nancy; Ladd, Carol; Woodgate, Rebecca

    2018-02-01

    From 2010 to 2015, moorings were deployed on the northern Chukchi Sea at nine sites. Deployment duration varied from 5 years at a site off Icy Cape to 1 year at a site north of Hanna Shoal. In addition, 39 satellite-tracked drifters (drogue depth 25-30 m) were deployed in the region during 2012-2015. The goals of this manuscript are to describe currents in the Chukchi Sea and their relationship to ice and winds. The north-south pressure gradient results in, on average, a northward flow over the Chukchi shelf, which is modified by local winds. The volume transport near Icy Cape (˜0.4 Sv) was ˜40% of flow through Bering Strait and varied seasonally, accounting for >50% of summer and ˜20% of winter transport in Bering Strait. Current direction was strongly influenced by bathymetry, with northward flow through the Central Channel and eastward flow south of Hanna Shoal. The latter joined the coastal flow exiting the shelf via Barrow Canyon. Drifter trajectories indicated the transit from Bering Strait to the mouth of Barrow Canyon took ˜90 days during the ice-free season. Most (˜70%) of the drifters turned westward at the mouth of Barrow Canyon and continued westward in the Chukchi Slope Current. This slope flow was largely confined to the upper 300 m, and although it existed year-round, it was strongest in spring and summer. Drifter trajectories indicated that the Chukchi Slope Current extends as far west as the mouth of Herald Canyon. The remaining ˜30% of the drifters turned eastward or were intercepted by sea ice.

  7. Multi-model ensemble combinations of the water budget in the East/Japan Sea

    Science.gov (United States)

    HAN, S.; Hirose, N.; Usui, N.; Miyazawa, Y.

    2016-02-01

    The water balance of East/Japan Sea is determined mainly by inflow and outflow through the Korea/Tsushima, Tsugaru and Soya/La Perouse Straits. However, the volume transports measured at three straits remain quantitatively unbalanced. This study examined the seasonal variation of the volume transport using the multiple linear regression and ridge regression of multi-model ensemble (MME) methods to estimate physically consistent circulation in East/Japan Sea by using four different data assimilation models. The MME outperformed all of the single models by reducing uncertainties, especially the multicollinearity problem with the ridge regression. However, the regression constants turned out to be inconsistent with each other if the MME was applied separately for each strait. The MME for a connected system was thus performed to find common constants for these straits. The estimation of this MME was found to be similar to the MME result of sea level difference (SLD). The estimated mean transport (2.42 Sv) was smaller than the measurement data at the Korea/Tsushima Strait, but the calibrated transport of the Tsugaru Strait (1.63 Sv) was larger than the observed data. The MME results of transport and SLD also suggested that the standard deviation (STD) of the Korea/Tsushima Strait is larger than the STD of the observation, whereas the estimated results were almost identical to that observed for the Tsugaru and Soya/La Perouse Straits. The similarity between MME results enhances the reliability of the present MME estimation.

  8. Indian Ocean dipole modulated wave climate of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Anoop, T.R.; SanilKumar, V.; Shanas, P.R.; Glejin, J.; Amrutha, M.M.

    are available on the website of the Japanese Agency of Marine–Earth Science and Technology (www.jamstec.go.jp). The tropical IO displays strong inter-annual climate vari- ability associated with the El Niño–Southern Oscillation (ENSO) and the IOD (Murtugudde et... in this study and the details of the numerical mod- Ocean Sci., 12, 369–378, 2016 www.ocean-sci.net/12/369/2016/ T. R. Anoop et al.: IOD modulated waves in Arabian Sea 371 els are described in Sect. 2. Section 3 describes results and discussion, and the main...

  9. Glaciotectonic deformations in the Jammerbugt and glaciodynamic development in the eastern North Sea

    DEFF Research Database (Denmark)

    Pedersen, Stig A. Schack; Boldreel, Lars Ole

    2017-01-01

    –Early Weichselian Skærumhede Group, indicating a Saalian age of the glaciotectonic deformation. The balancing of the thrust fault structures shows that the thrust sheets in the tailing end of the complex had their source in the Skagerrak sea. The hole caused by displacement contributed to formation of the Skagerrak......The Quaternary geology in the eastern part of the North Sea is characterized by large-scale glaciotectonic complexes. The northernmost complex is the Jammerbugt Glaciotectonic Complex here addressed, which occupies an area of more than 300km2. It was recently recognized during an investigation...... of conventional seismic profiles located about 10km offshore the west coast of northern Denmark. The deformed bedrock includes the main part of the Cretaceous Chalk Group in the North Sea. In the northern part of the complex the detachment surface is situated in Lower Cretaceous greensand about 400m below sea...

  10. Microcrystalline dolomite within massive Japan Sea methane hydrate: origin and development ascertained by inclusions within inclusions.

    Science.gov (United States)

    Snyder, G. T.; Kakizaki, Y.; Matsumoto, R.; Suzuki, Y.; Takahata, N.; Sano, Y.; Tanaka, K.; Tomaru, H.; Imajo, T.; Iguchi, A.

    2017-12-01

    Microcrystalline dolomite grains were recently discovered as inclusions within relatively pure massive gas hydrate recovered from the Joetsu Basin area of the Japan Sea. These grains presumably formed as a consequence of the highly saline conditions in fluid inclusions which developed between coalescing grain boundaries within the growing hydrate. Stable carbon and oxygen isotopic composition of the dolomite is consistent with crystal growth occurring within such fluids. In addition to stable isotopes, we investigate trends in Mg/Ca ratios of the grains as well as the composition of inclusions which exist within the dolomites. Preliminary research shows that these inclusions retain valuable information as to the conditions which existed at the time of formation, as well as the dynamics of these extensive hydrate deposits over time. This study was conducted under the commission from AIST as a part of the methane hydrate research project funded by METI (the Ministry of Economy, Trade and Industry, Japan).

  11. Proposal of great eastern Japan earthquake. Message from Fukushima Medical University

    International Nuclear Information System (INIS)

    Kikuchi, Shin-ichi

    2012-01-01

    Described are what Fukushima Medical University (FMU) faced and how FMU responded at Fukushima Daiichi Power Plant (FDPP) Accident by hydrogen explosions (Mar. 12 and 14, 2011) following the Great Eastern Japan Earthquake (Mar. 11). The Accident accompanying the forced evacuation of resident in the area 20 km afar from FDPP brought about the concern, fear and anger, different from those in the neighboring Miyagi Prefecture; and strong psychosomatic stress; as well as the significant alteration of composition of generation in population and in sickness proportion in the whole Prefecture. Under these circumstances, FMU decided to hold information in common and make a service window single, to give the top leadership with rough-and-ready practice and a flexible policy, which all were the president's responsibility for making staff work relieved and united. For holding information in common, frequent meetings of the whole FMU personnel were held (42 times from Mar. 11 to Nov.) and of managing staff (81 times until Nov.). During the period, FMU took measures to meet with the situation of patient receiving and transporting, measures against rumor, and cooperation with related medical institutions. Medicare support included the acute phase medicare, and planning and practice of healthcare management for >30 years onward in the Prefecture. The author summarizes 9 lessons proposed from the Disaster to be considered hereafter, like the system perfection at an emergency, more education about radiation for the resident and medicare staff, measures for aging of engineers and scientists related to atomic energy, and so on. As well, 6 lessons are summarized for the next generation using old aphorism and recent commentary in media. The people should follow the excellent leader at crisis; but it's the problem whether there is such a leader on site or in administration at the very time. (T.T.)

  12. Fungal community in sclerotia of Japanese Beech forest soils in north eastern Japan

    Science.gov (United States)

    Fathia Amasya, Anzilni; Narisawa, Kazuhiko; Watanabe, Makiko

    2014-05-01

    Sclerotia are resting structures of ectomycorrhizal fungi and appear as a response to unfavorable environmental conditions such as desiccation. They are hard, black, comparatively smooth and mostly spherical. Sclerotia are formed in rhizosphere and the 14C ages of sclerotia from A horizons of volcanic ash soils may range from modern until ca. 100~1,200 yr B.P. Most sclerotia-forming fungal species are known to be host-specific plant pathogens and therefore their abundance may indicate the presence of their host plants. The purpose of this study was to investigate fungal communities in sclerotia with an interest in describing the existing or may have previously existed host plant community. To investigate fungal community inside of sclerotia by 16S rDNA gene clone library, several hundred of sclerotia (ca. 1g) were collected from Fagus crenata forest soil in north eastern Japan. The rDNA ITS regions were then amplified by the PCR using primer pair ITS-1F/ITS-4. Aliquots of the amplified DNA were digested with restriction endonucleases AluI, Hae III, and HhaI to obtain ITS-RFLPs. To obtain the fungal community profiles a quenching fluorescence primer was used for real-time quantitative PCR (qPCR) assay to monitor the PCR amplification and then used for T-RFLP. The predominant group determined by clone library analysis from the sclerotia was Ascomycota: Arthrinium arundinis, which has been reported to be one of the soil fungal species responsible for bamboo degradation and a pathogen for many species belonging to Poaceae family.

  13. Thermocline circulation and ventilation of the East/Japan Sea, part I: Water-mass characteristics and transports

    Science.gov (United States)

    You, Yuzhu; Chang, Kyung-Il; Yun, Jae-Yul; Kim, Kyung-Ryul

    2010-07-01

    three other major convection sites of the world's oceans, the Gulf of Lions, Labrador Sea and Greenland Sea, showing some common and distinctive features, especially the extremely low salinity of the EJS. Water-mass properties on neutral density surfaces are analyzed with the water-mass Turner angle (WTu) and circulation and transport are deducted from geostrophic calculations. From the 15-year mean hydrography, a basin-wide net annual mean transport of about 2.10±0.29 Sv (1 Sv=10 6 m 3 s -1) is estimated with summer and winter transports of 2.56±0.36 and 1.63±0.23 Sv, respectively. This transport is slightly less than the annual mean transport of the Tsushima Current at the KTS, 2.4 Sv from cable and 2.3 Sv from other direct current meter and geostrophic methods but matches the ±14% error bar of ±0.29 Sv adjusted by ±150 dbar from the reference level of 800 dbar. This error bar is close to the error of ±0.34 Sv determined from water-mass conservation residual in a separated study. Three mechanisms are discovered to explain the seasonal difference in the Tsushima Current transports: the stronger winter Ekman pumping, outcropping and southward crossing flow. During winter, the Tsushima Current branches are imposed under strong wind stress curl in the Ulleung Basin and Yamato Basin, showing a doubling Ekman downwelling transport, partly weakening the Tsushima Current flow in the eastern boundary. Meanwhile the thermocline isopycnal surfaces outcrop in winter, reducing volume transport due to reduced space and thickness. The southward currents in the southern Ulleung Basin and Yamato Basin are perpendicular to the Tsushima Current branches west of Japan, which weakens the eastern boundary current in winter.

  14. Response of yellowtail, Seriola quinqueradiata, a key large predatory fish in the Japan Sea, to sea water temperature over the last century and potential effects of global warming

    Science.gov (United States)

    Tian, Yongjun; Kidokoro, Hideaki; Watanabe, Tatsuro; Igeta, Yosuke; Sakaji, Hideo; Ino, Shingo

    2012-03-01

    We examined the long-term variability in the abundance of yellowtail Seriola quinqueradiata and its relationship with sea water temperature in the Japan Sea, which is one of the most rapidly warming large marine ecosystems in the world ocean. The total catch of yellowtail has ranged from 14,000 to 77,000 t with an increasing trend over the last century. Decadal-scale variability was found for yellowtail with significant shifts occurring around 1911, 1931, 1950, 1973, 1989 and 2000, which was in accordance with sea surface temperatures (SST). In particular, there was close correspondence between water temperature and catch in the Japan Sea; significant and positive correlations between SSTs and catch indicated increasing water temperature in the Tsushima Warm Current region has led to positive effects on migration and recruitment of yellowtail. SST mapping of optimum water temperature for yellowtail habitat indicated a northward extension in distribution and overwintering areas of yellowtail in the Japan Sea during the warm 1990s, suggested that the migration pattern, distribution and overwintering area are largely dictated by SST. Hence, potential impacts of global warming on migration, distribution and fisheries grounds of yellowtail in the Japan Sea were estimated based on the prediction of the IPCC A1B scenario which indicated northward extension in distribution and overwintering region with global warming and will have large impacts on the fisheries for yellowtail.

  15. Cenozoic structures and the tectonic evolution of the eastern North Sea

    DEFF Research Database (Denmark)

    Clausen, O.R.; Nielsen, S.B.; Egholm, D.L.

    2011-01-01

    Abundant seismic sections and well data from the Cenozoic succession in the eastern North Sea area generally reveal normal faulting, salt tectonics and localized tectonic inversion. However, inferences on the Cenozoic dynamic evolution of the region require thorough analysis of interactions between...... or cover tectonism took place. Our objectives are thus 1) to analyze the interaction between basement and cover structures, and if possible 2) to relate the structures to the regional tectonic evolution. The Zechstein evaporites pinch out onto the Ringkøbing-Fyn High, which in the eastern North Sea...... including decompaction in the Central Graben along the Arne-Elin trend shows that two phases of basement related inversion took place duringthe Paleocene-Eocene and the Oligocene. Halokinetics and differential compaction across the Paleogene inversion structure explain later tectonic signals...

  16. Variation of paleo-productivity and terrigenous input in the eastern Arabian Sea during the past 100 ka

    Digital Repository Service at National Institute of Oceanography (India)

    Ishfaq, A.M.; Pattan, J.N.; Matta, V.M.; Banakar, V.K.

    A 4.1m long sediment core from the eastern Arabian Sea is studied using multiple geochemical proxies to understand the variation of productivity and terrigenous matter supply during the past 100 ka. The temporal variation in element concentration...

  17. Offshore limit of coastal ocean variability identified from hydrography and altimeter data in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Swamy, G.N.; Somayajulu, Y.K.

    In this communication, we describe a hitherto-unknown offshore limit to the coastal ocean variability signatures away from the continental shelf in the eastern Arabian Sea, based on hydrographic observations and satellite altimeter (TOPEX...

  18. Temperature, salinity, and dissolved oxygen profile data from MULTIPLE SHIPS in the Eastern Mediterranean Sea: (NODC Accession 9400176)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conductivity, Temperature and Depth (CTD) and other data were collected in Mediterranean Sea, Eastern Basin as part of Mediterranean Ocean Circulation project. Data...

  19. Acoustic-Trawl Survey of Walleye Pollock on the Eastern Bering Sea Shelf (DY1407, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey on the eastern Bering Sea...

  20. 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.

    report the spatial variations in distribution of phytoplankton groups along the north-south transect in the eastern Arabian Sea based on marker pigments supported with flow-cytometric and microscopic analyses. 15 phytoplankton pigments were identified...

  1. Hydrography and biogeochemistry of the north western Bay of Bengal and the north eastern Arabian Sea during winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Laluraj, C.M.; Jyothibabu, R.; Madhu, N.V.; Muraleedharan, K.R.; Vijay, J.G.; Maheswaran, P.A.; Ashraf, T.T.M.; Nair, K.K.C.; Achuthankutty, C.T.

    The north eastern Arabian Sea and the north western Bay of Bengal within the Indian exclusive economic zone were explored for their environmental characteristics during the winter monsoons of 2000 and 2001 respectively. The two regions were found...

  2. AFSC/NMML: Cetacean line-transect survey in the eastern Bering Sea shelf; 1999, 2000, 2002, and 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC.s echo integration trawl surveys for...

  3. Comparison of ERA-Interim waves with buoy data in the eastern Arabian Sea during high waves

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    Wave data during extreme conditions is required for planning structures and shipping routes Since the measured wave data is still sparse in the eastern Arabian Sea wave information is mainly derived from wave model dataset and satellite derived data...

  4. Census of biodiversity in marine caves of the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    V. GEROVASILEIOU

    2015-03-01

    Full Text Available Scientific information on the biodiversity of marine caves in the eastern Mediterranean is limited, especially when considering the extensively studied caves of the north-western and central Mediterranean. Aiming to enhance current knowledge regarding cave communities, this study represents a first assessment of the marine cave biota of the eastern Mediterranean, as this has been defined by the European Union’s Marine Strategy Framework Directive (MSFD. Information retrieved from an extensive overview of relevant scientific documents was combined with original data recorded from 23 marine caves of the north-eastern Mediterranean. Our results report a total of 520 taxa recorded in eastern Mediterranean marine caves to date, the majority of which are sponges, polychaetes, rhodophytes, bivalves, fishes, and gastropods. These include several protected, endemic, and alien species. However, not all taxonomic groups have been equally studied among different areas and future studies are expected to raise the number of endemic and alien species. The overall observed trend is that the reported species number is generally related to sampling effort and scientific expertise. The most well-studied marine cave communities of the eastern Mediterranean are those of the Aegean Sea (especially its northern sector, which presented the highest number of species, followed by those of the Levantine. Furthermore, our research in Aegean caves revealed numerous new records for the marine cave fauna of the eastern basin, while several species are reported for the first time in the marine cave habitat. The critical need for further scientific research, monitoring, and conservation of this unique ecosystem was highlighted by (i the presence of certain species endemic to the eastern Mediterranean coupled with a high proportion of alien species, especially in the Levantine, and (ii the marine cave habitat availability in isolated insular areas of the eastern Mediterranean.

  5. Properties of cloud condensation nuclei (CCN) in the trade wind marine boundary layer of the Eastern Caribbean Sea

    OpenAIRE

    T. B. Kristensen; T. Müller; K. Kandler; N. Benker; M. Hartmann; J. M. Prospero; A. Wiedensohler; F. Stratmann

    2015-01-01

    Cloud optical properties in the trade winds over the Eastern Caribbean Sea have been shown to be sensitive to cloud condensation nuclei (CCN) concentrations. The objective of the current study was to investigate the CCN properties in the marine boundary layer (MBL) in the Eastern Caribbean, in order to assess the respective roles of organic species, long-range transported mineral dust, and sea salt particles. Measurements were carried out in June–July ...

  6. Radionuclides and trace metals in eastern Mediterranean Sea algae

    Energy Technology Data Exchange (ETDEWEB)

    Al-Masri, M.S. E-mail: msmasri@aec.org.sy; Mamish, S.; Budier, Y

    2003-07-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that {sup 137}Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg{sup -1} dry weight) while the levels of naturally occurring radionuclides, such as {sup 210}Po and {sup 210}Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg{sup -1} dry weight) for {sup 210}Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate {sup 210}Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br.

  7. Radionuclides and trace metals in eastern Mediterranean Sea algae

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mamish, S.; Budier, Y.

    2003-01-01

    Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that 137 Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg -1 dry weight) while the levels of naturally occurring radionuclides, such as 210 Po and 210 Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg -1 dry weight) for 210 Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate 210 Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br

  8. Oceanic core complexes in the Philippine Sea: results from Japan's extended continental shelf mapping

    Science.gov (United States)

    Ohara, Y.; Yoshida, T.; Nishizawa, A.

    2013-12-01

    The United Nations Commission on the Limits of the Continental Shelf (CLCS) issued its recommendations on Japan's extended continental shelf in April 2012, confirming Japan's rights over the vast areas within the Philippine Sea and Pacific Plates. Japan submitted information on the limits of its continental shelf beyond the EEZ to the CLCS on November 2008, which was the result of 25 years of nation's continental shelf survey project since 1983, involving all of Japan's agency relevant to geosciences. The huge geological and geophysical data obtained through the project give the scientists unprecedented opportunity to study the geology and tectonics of the Philippine Sea and Pacific Plates. In this contribution, we show such an example from the Philippine Sea Plate, relevant to the global mid-ocean ridge problem. Oceanic core complexes (OCC) are dome-shaped bathymetric highs identified in mid-ocean ridges, interpreted as portions of the lower crust and/or upper mantle denuded via low-angle detachment faulting. OCCs are characterized morphologically by axis-normal striations (corrugations, or mullion structure) on the dome, and exposures of mantle peridotite and/or lower crustal gabbro. A strikingly giant OCC (named 'Godzilla Megamullion') was discovered in the Parece Vela Basin by the continental shelf survey project in 2001. Godzilla Megamullion is morphologically the largest OCC in the world, consisting mainly of fertile mantle peridotite along its entire length of over 125 km. Following its discovery in 2001, several academic cruises investigated the structure in detail, providing numerous important findings relevant to mid-ocean ridge tectono-magmatic processes and Philippine Sea evolution, including the slow- to ultraslow-spreading environment for denudation of the detachment fault (< 2.5 cm/y) and associated decreasing degree of partial melting of the peridotites towards the termination of Godzilla Megamullion. In addition to Godzilla Megamullion, several

  9. Radium isotopes in the Orinoco estuary and Eastern Caribbean Sea

    International Nuclear Information System (INIS)

    Moore, W.S.; Todd, J.F.

    1993-01-01

    Radium isotopes provide a means of identifying the source of freshened waters in the ocean and determining the time elapsed since these waters were in the estuary. The authors present evidence that during April, waters from the Amazon mixing zone pass within 50 km of the mouth of the Orinoco River. These Amazon waters are characterized by a lower 228 Ra/ 226 Ra activity ratio (AR) than are waters from the Orinoco at similar salinities. During autumn, the increased discharge of the Orinoco displaces the freshened Amazon waters seaward, yet the two can be distinguished clearly. Within the Caribbean Sea, waters of Orinoco origin carry a characteristic radium signature including excess activities of 224 Ra. This isotope may be used to estimate the time elapsed since the waters were removed from contact with sediments. Current speeds based on 224 Ra dating ranged from 15 to 33 cm/s during April. The radium isotopes also provide an assessment of sediment mixing in the estuary. During low discharge (April), considerable mixing of older sediment by physical or biological processes or dredging maintained high activities of 228 Ra in the estuary and produced the highest 228 Ra/ 226 Ra AR's yet measured in any estuary. During high discharge (September), a large fraction of the 228 Ra was derived from desorption from fresh sediment rather than mixing of older sediments. Activities of 224 Ra were high in the estuary during both high and low discharge, indicating that considerable mixing of recently introduced sediment must occur during each period. During April, 224 Ra and 228 Ra activities in the water were about equal, indicating that most of the sediment being resuspended had been stored in the estuary long enough to reestablish radioactive equilibrium in the 232 Th decay series (i.e., 20 years). 19 refs., 11 figs., 3 tabs

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

    Directory of Open Access Journals (Sweden)

    C. C.S. HANNIDES

    2015-05-01

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

  11. Microbiota analysis of Caspian Sea yogurt, a ropy fermented milk circulated in Japan.

    Science.gov (United States)

    Uchida, Kenji; Akashi, Keiko; Motoshima, Hidemasa; Urashima, Tadasu; Arai, Ikichi; Saito, Tadao

    2009-04-01

    We analyzed the microbiota of domestic ropy fermented milk, Caspian Sea yogurt (or 'kasupikai yohguruto' in Japanese), circulated in Japan. We collected six varieties from five localities. Lactococcus (L) lactis ssp. cremoris was isolated from all samples as the dominant strain at levels of 10(8)-10(9) CFU/g. We show this strain produces an extracellular polysaccharide (EPS) that causes the unique characteristic viscosity of the product. From analysis of the RAPD pattern of 60 bacterial isolates from the six samples, we found that 59 strains from a total of 60 isolates were identical and produced this viscosity. Furthermore, PFGE analysis of representative strains from each sample indicated that the isolates could be classified into four subgroups. This suggests these L. lactis ssp. cremoris strains found in Caspian Sea yogurt may have been slightly mutated during subculture in Japan. In addition, Lactobacillus (L.) sakei ssp. sakei were isolated from three samples; L. plantarum, Gluconoacetobacter sacchari and Acetobacter aceti were isolated from two samples; and L. paracasei, L. kefiri, Leuconostoc (Leu.) mesenteroides were isolated from one sample.

  12. Formation of Barents Sea Branch Water in the north-eastern Barents Sea

    Directory of Open Access Journals (Sweden)

    Vidar S. Lien

    2013-09-01

    Full Text Available The Barents Sea throughflow accounts for approximately half of the Atlantic Water advection to the Arctic Ocean, while the other half flows through Fram Strait. Within the Barents Sea, the Atlantic Water undergoes considerable modifications before entering the Arctic Ocean through the St. Anna Trough. While the inflow area in the south-western Barents Sea is regularly monitored, oceanographic data from the outflow area to the north-east are very scarce. Here, we use conductivity, temperature and depth data from August/September 2008 to describe in detail the water masses present in the downstream area of the Barents Sea, their spatial distribution and transformations. Both Cold Deep Water, formed locally through winter convection and ice-freezing processes, and Atlantic Water, modified mainly through atmospheric cooling, contribute directly to the Barents Sea Branch Water. As a consequence, it consists of a dense core characterized by a temperature and salinity maximum associated with the Atlantic Water, in addition to the colder, less saline and less dense core commonly referred to as the Barents Sea Branch Water core. The denser core likely constitutes a substantial part of the total flow, and it is more saline and considerably denser than the Fram Strait branch as observed within the St. Anna Trough. Despite the recent warming of the Barents Sea, the Barents Sea Branch Water is denser than observed in the 1990s, and the bottom water observed in the St. Anna Trough matches the potential density at 2000 m depth in the Arctic Ocean.

  13. Viscoelastic crustal deformation by magmatic intrusion: A case study in the Kutcharo caldera, eastern Hokkaido, Japan

    Science.gov (United States)

    Yamasaki, Tadashi; Kobayashi, Tomokazu; Wright, Tim J.; Fukahata, Yukitoshi

    2018-01-01

    Geodetic signals observed at volcanoes, particularly their temporal patterns, have required us to make the correlation between the surface displacement and magmatic process at depth in terms of viscoelastic crustal rheology. Here we use a parallelized 3-D finite element model to examine the response of the linear Maxwell viscoelastic crust and mantle to the inflation of a sill in order to show the characteristics of a long-term volcano deformation. In the model, an oblate-spheroidal sill is instantaneously or gradually inflated in a two-layered medium that consists of an elastic layer underlain by a viscoelastic layer. Our numerical experiments show that syn-inflation surface uplift is followed by post-inflation surface subsidence as the viscoelastic substrate relaxes. For gradual inflation events, the magnitude of inflation-induced uplift is reduced by the relaxation, through which the volume of a magma inferred by matching the prediction of an elastic model with observed surface uplift could be underestimated. For a given crustal viscosity, sill depth is the principal factor controlling subsidence caused by viscoelastic relaxation. The subsidence rate is highest when the inflation occurs at the boundary between the elastic and the viscoelastic layers. The mantle viscosity has an insignificant impact unless the depth of the inflation is greater than a half the crustal thickness. We apply the viscoelastic model to the interferometric synthetic aperture radar (InSAR) data in the Kutcharo caldera, eastern Hokkaido, Japan, where the surface has slowly subsided over a period of approximately three years following about a two-year period of inflation. The emplacement of a magmatic sill is constrained to occur at a depth of 4.5 km, which is significantly shallower than the geophysically imaged large-scale magma chamber. The geodetically detected deformation in the caldera reflects the small-scale emplacement of a magma that ascended from the deeper chamber, but not the

  14. A possible adaptation of herring feeding migrations to a change in timing of the Calanus finmarchicus season in the eastern North Sea

    NARCIS (Netherlands)

    Corten, A.

    2000-01-01

    During the first years after the re-opening of the North Sea herring fishery in 1983, a relatively high proportion of the catches in early summer was taken in the eastern North Sea. After 1986, the proportion of the catch in the eastern North Sea gradually declined. It is assumed that the high

  15. Geothermal structure of the eastern Black Sea basin and the eastern Pontides orogenic belt: Implications for subduction polarity of Tethys oceanic lithosphere

    Directory of Open Access Journals (Sweden)

    Nafiz Maden

    2013-07-01

    Full Text Available The numerical results of thermal modeling studies indicate that the lithosphere is cold and strong beneath the Black Sea basin. The thermal lithospheric thickness increases southward from the eastern Pontides orogenic belt (49.4 km to Black Sea basin (152.2 km. The Moho temperature increases from 367 °C in the trench to 978 °C in the arc region. The heat flow values for the Moho surface change between 16.4 mW m−2 in the Black Sea basin and 56.9 mW m−2 in the eastern Pontides orogenic belt. Along the southern Black Sea coast, the trench region has a relatively low geothermal potential with respect to the arc and back-arc region. The numerical studies support the existence of southward subduction beneath the Pontides during the late Mesozoic–Cenozoic.

  16. Distributions and fluxes of methylmercury in the East/Japan Sea

    Science.gov (United States)

    Yang, Jisook; Kim, Hyunji; Kang, Chang-Keun; Kim, Kyung-Ryul; Han, Seunghee

    2017-12-01

    The East/Japan Sea (EJS) is well ventilated to deep water via brine rejection from ice formations and thermohaline convection, resulting in a short overturning period in several decades. Due to these characteristics, the dissolved oxygen concentration in the EJS deep water is much higher (190-200 μg L-1 at 3000 m water depth) than that found at the same depths of the Northwestern Pacific (30 μg L-1) or anywhere in the Pacific Ocean. The total mercury (THg) and methylmercury (MeHg) distributions, and MeHg mass budgets were investigated to identify how the EJS's distinct circulation pattern affects Hg speciation. Whereas the THg concentration in the surface seawater (ranging from 0.20 to 1.2 pM, mean 0.59 ± 0.24 pM) showed no site variation between the Japan Basin and the Ulleung Basin, the MeHg concentration in the surface seawater was significantly higher (p < 0.05) in the Japan Basin (32 ± 24 fM) than in the Ulleung Basin (12 fM), with a south to north increasing gradient. This observation was supported by the mass budget estimation showing that upward diffusion as well as net methylation of Hg(II) was the primary source of MeHg in the surface seawater; the upward diffusion value was higher in the Japan Basin (3.2 nmol m-2 yr-1) than in the Ulleung Basin (1.9 nmol m-2 yr-1) due to the shallow thermocline depths in the Japan Basin. In contrast, the MeHg concentration in deep seawater (1000-3000 m) was similar between the Japan Basin (530 ± 87 fM) and the Ulleung Basin (610 ± 99 fM) and significantly (p < 0.05) higher than in the North Pacific (24 ± 40 fM) or North Atlantic (87 ± 96 fM) deep seawater. The Hg(II) methylation capacity, represented by the MeHg concentration normalized to apparent oxygen utilization, was also higher for the EJS deep water (0.0048) than the Northeastern Pacific (0.0030) and Northwestern Pacific (0.0025) intermediate waters, implying that the short overturning period of EJS may cause exclusively high MeHg concentrations in the

  17. Intermediate to deep water hydrographic changes of the Japan Sea over the past 10 Myr, inferred from radiolarian data (IODP Exp. 346, Site U1425)

    Science.gov (United States)

    Matsuzaki, Kenji M.; Itaki, Takuya; Tada, Ryuji; Kurokawa, Shunsuke

    2017-04-01

    The Japan Sea is a back-arc basin opened under a continental rifting during the Early to Middle Miocene (ca. 25-13 Ma). This area is characterized by active tectonism, which drastically modified the Japan Sea paleogeography such as the sill depth of its key straits. In modern condition, the Japan Sea is connected to adjacent marginal seas and the Pacific Ocean by four straits shallower than 130 m. These straits are the Tsushima Strait connecting to the East China Sea, the Tsugaru Strait connecting to the Pacific, and the Soya and Mamiya Straits connecting to the Sea of Okhotsk. Therefore, the intermediate and deep water of the Japan Sea is isolated, leading the formation of a unique and regional deep sea water, known as the Japan Sea Proper Water. However, past studies show that during the late Miocene and Pliocene, only the Tsugaru Strait connecting to the North Pacific was opened. This strait was deeper during Plio-Miocene and have likely enable inflow of deep to intermediate water of the North Pacific in the Japan Sea. Radiolarians are one of the planktic micro-organisms group bearing siliceous skeletons. Their species comprise shallow to deep water dwellers, sensitive to changes in sea water physical/ecological properties forced by climate changes. Their fossils are known for be well preserved in the deep-sea sediments of the North Pacific. Therefore, in this study we propose to monitor changes in intermediate to deep water hydrography of the Japan Sea since the late Miocene, using radiolarian as an environmental proxy. In 2013 the IODP Expedition 346 retrieved sediment cores at different sites in the Japan Sea. In this study, we have analyzed 139 core sediments samples collected at Site U1425. This site is situated in the middle of the Yamato Bank. We selected this site because the past 10 Myr could be recovered continuously without hiatuses. Changes in radiolarian assemblages reveal that the oceanographic setting of the Japan Sea changed drastically at ca. 2

  18. Recent changes in deep water formation and spreading in the eastern Mediterranean Sea: a review

    Science.gov (United States)

    Lascaratos, Alex; Roether, Wolfgang; Nittis, Kostas; Klein, Birgit

    1999-08-01

    Observations of the last decade testify that the characteristics of the deep thermohaline circulation in the Eastern Mediterranean Sea have changed thoroughly. The source of the most dense waters of the basin has moved from the Adriatic to the Aegean Sea. This new source has proved to be very efficient since the estimated formation rate for the period 1989-95 was more than 1 Sv, about three times more than the dense water formation rate of the Adriatic Sea. These new waters with hydrological characteristics, that are warmer and more saline, have replaced almost 20% of the older deep waters of the basin, and have uplifted the deep isopycnals by about 500 m. This major event can be attributed to important meteorological anomalies in the Eastern Mediterranean and to changes of circulation patterns. The extended dry period of 1988-93 and the exceptionally cold winters of 1987 and 1992-93 created favorable conditions for increased formation of dense water in the Aegean. Furthermore, changes in the circulation patterns in the intermediate water range (Levantine Intermediate Water LIW and Cretan Intermediate Water), themselves possibly linked to meteorological anomalies, appear to have played an important role in the redistribution of salt. As a result of an interruption to exchanges between the Ionian and Levantine Basin, the salinities in the latter started to rise, high salinity waters were diverted into the Aegean [ Malanotte-Rizzoli, P., Manca, B. B., Ribera dAcala, M., & Theocharis, A. (1998). The Eastern Mediterranean in the 80s and in the 90s: the big transition emerged from the POEM-BC observational evidence. Rapport du Commission International de la Mer Medittanee, 35, 174-175] and the westward transport of LIW was reduced. An additional effect of the deep water discharge from the Aegean and the resulting uplifting of mid-depth waters was to lower salinities in the LIW layer. This effect is most strongly felt in the Ionian Sea. A 3-D primitive equation numerical

  19. Establishment of a database for Japan Sea parameters on marine environment and radioactivity (JASPER). Volume 1: Anthropogenic radionuclides

    International Nuclear Information System (INIS)

    Ito, Toshimichi; Otosaka, Shigeyoshi; Suzuki, Takashi; Tanaka, Takayuki; Tsuneyama, Teppei; Togawa, Orihiko

    2007-03-01

    A database for Japan Sea parameters on marine environment and radioactivity (JASPER) has been established by the Japan Atomic Energy Agency as one of final products of the Japan Sea expeditions (phase I), carried out covering the Exclusive Economic Zones of Japan and Russian Federation. And now, the part of anthropogenic radionuclides in the JASPER database has been opened to the public, as the first volume in a series of partworks consisted of other radionuclides and oceanographic parameters. At the beginning of this report (chapter 1), backgrounds, objectives and a brief overview of this report are given as an introduction. Then, specifications of this database and methodologies in obtaining the concentration data are described in chapter 2. The data stored in the database are presented in tabular and figure forms in chapter 3. Finally, concluding remarks are assigned in chapter 4. In the present, 252 data records are stored in the database including 193 data for 90 Sr and 137 Cs, 163 data for 238 Pu and 236 data for 239+240 Pu obtained from seawater, seabed sediment and filtered particle with support data. By establishing the database, recent features of the Japan Sea environment have been recorded using very possible parameter for us. We believe that this database would be a strong tool for the purposes of monitoring for contamination of the Japan Sea by anthropogenic radionuclides, studies of material transport in the sea and development and validation of models for numerical simulations. Furthermore, it is being prepared that the database is linked to MARIS (Marine Information System) of International Atomic Energy Agency's Marine Environment Laboratories in order to contribute the world-wide study and monitoring of anthropogenic radionuclides in marine environment. (author)

  20. Discovery of chemosynthesis-based association on the Cretaceous basal leatherback sea turtle from Japan

    Directory of Open Access Journals (Sweden)

    Robert G. Jenkins

    2017-11-01

    Full Text Available We report a Late Cretaceous chemosynthetic community fueled by decomposing basal leatherback sea turtle on the ocean floor in the western Pacific. The fossil association representing this community has been recovered from the matrix of a concretion containing a single carapace of Mesodermochelys sp. from Late Cretaceous outer shelf to upper slope deposit of northern Hokkaido, Japan. The carapace displays boreholes most likely performed by boring bivalves, and is associated with molluscan shells, mainly Provanna cf. nakagawensis and Thyasira tanabei. Since this association is similar to fauna already known from Late Cretaceous hydrocarbon seeps, sunken wood, and plesiosaur-falls in Hokkaido, it is suggested that all types of chemosynthesis-based communities in the Late Cretaceous of western Pacific may have belonged to the same regional pool of animals and were not yet fully differentiated into three independent types of communities as it is known today. This finding also indicates that the sulfophilic stage of the vertebrate-fall communities was supported not only by plesiosaur carcasses, which were previously reported, but also by sea turtle carcasses. It highlights the possibility of surviving vertebrate-fall communities through the end-Cretaceous mass extinction event on carcasses of sea turtles which are the only large marine vertebrates surviving this event.

  1. Radioactive contamination mapping of northeastern and eastern Japan by a car-borne survey system, Radi-Probe.

    Science.gov (United States)

    Kobayashi, Shingo; Shinomiya, Takayuki; Kitamura, Hisashi; Ishikawa, Takahiro; Imaseki, Hitoshi; Oikawa, Masakazu; Kodaira, Satoshi; Miyaushiro, Norihiro; Takashima, Yoshio; Uchihori, Yukio

    2015-01-01

    We constructed a new car-borne survey system called Radi-Probe with a portable germanium gamma-ray spectrometer onboard a cargo truck, to identify radionuclides and quantify surface contamination from the accident at Fukushima Dai-ichi Nuclear Power Station. The system can quickly survey a large area and obtain ambient dose equivalent rates and gamma-ray energy spectra with good energy resolution. We also developed a new calibration method for the system to deal with an actual nuclear disaster, and quantitative surface deposition densities of radionuclides, such as (134)Cs and (137)Cs, and kerma rates of each radionuclide can be calculated. We carried out car-borne survey over northeastern and eastern Japan (Tohoku and Kanto regions of Honshu) from 25 September through 7 October 2012. We discuss results of the distribution of ambient dose equivalent rate H(∗)(10), (134)Cs and (137)Cs surface deposition densities, spatial variation of (134)Cs/(137)Cs ratio, and the relationship between surface deposition densities of (134)Cs/(137)Cs and H(∗)(10). The ratio of (134)Cs/(137)Cs was nearly constant within our measurement precision, with average 1.06 ± 0.04 in northeastern and eastern Japan (decay-corrected to 11 March, 2011), although small variations from the average were observed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Indo-Pacific sea surface temperature influences on failed consecutive rainy seasons over eastern Africa

    Science.gov (United States)

    Hoell, Andrew; Funk, Christopher C.

    2014-01-01

    Rainfall over eastern Africa (10°S–10°N; 35°E–50°E) is bimodal, with seasonal maxima during the "long rains" of March–April–May (MAM) and the "short rains" of October–November–December (OND). Below average precipitation during consecutive long and short rains seasons over eastern Africa can have devastating long-term impacts on water availability and agriculture. Here, we examine the forcing of drought during consecutive long and short rains seasons over eastern Africa by Indo-Pacific sea surface temperatures (SSTs). The forcing of eastern Africa precipitation and circulation by SSTs is tested using ten ensemble simulations of a global weather forecast model forced by 1950–2010 observed global SSTs. Since the 1980s, Indo-Pacific SSTs have forced more frequent droughts spanning consecutive long and short rains seasons over eastern Africa. The increased frequency of dry conditions is linked to warming SSTs over the Indo-west Pacific and to a lesser degree to Pacific Decadal Variability. During MAM, long-term warming of tropical west Pacific SSTs from 1950–2010 has forced statistically significant precipitation reductions over eastern Africa. The warming west Pacific SSTs have forced changes in the regional lower tropospheric circulation by weakening the Somali Jet, which has reduced moisture and rainfall over the Horn of Africa. During OND, reductions in precipitation over recent decades are oftentimes overshadowed by strong year-to-year precipitation variability forced by the Indian Ocean Dipole and the El Niño–Southern Oscillation.

  3. Why much of the Atlantic circulation enters the Caribbean Sea and very little of the Pacific circulation enters the Sea of Japan

    Science.gov (United States)

    Nof, Doron

    2000-01-01

    A peculiar aspect of western marginal seas is that some of them accommodate large transports whereas others, apparently similar seas, accommodate relatively small transports. For instance, about 30-40 Sv of Atlantic upper water passes through the Caribbean and yet only 2 Sv or so passes through the Sea of Japan. The passages connecting the Caribbean to the Atlantic are somewhat larger than their Sea of Japan counterparts, but the dimensions of the gaps are too similar to each other to account for the large difference in the transports. Four different baroclinic models are used to investigate the problem. First, we used a wind-driven, layer-and-a-half isopycnal model with an idealized basin and an adjacent marginal sea separated from the main basin by a thin and long island. In this scenario, thermocline water enters the marginal sea via a gap to the south of the island and exits the sea via a gap to the north of the island. The mean latitudinal position of the marginal sea is gradually increased and the numerical transport across the sea is measured. We then compared the transport determined this way to that computed using three analytical baroclinic models: Godfrey's island rule (Godfrey, J. S. (1989). A Sverdrup model of the depth-integrated flow for the world ocean allowing for island circulations. Geophysical and Astrophysical Fluid Dynamics, 45, 89-112.), the ‘ β-controlled’ transport formula (Nof, D. (1993). The penetration of Kuroshio water into the Sea of Japan. Journal of Physical Oceanography, 23, 797-807), and the general gap transport formula (Nof, D., (1995). Choked flows and wind-driven interbasin exchange. Journal of Marine Research, 53, 23-48). The results were also compared to Minato and Kimura's (Minato, S., & Kimura, R. (1980). Volume transport of the western boundary current penetrating into a marginal sea. Journal of the Oceanographic Society of Japan, 36, 185-195) barotropic calculations. All four baroclinic models show that, when the

  4. Zooplankton incidence in abnormally high sea surface temperature in the Eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    and internal waves may cause zooplankton abundance. Average biomass values in high sea surface temperature areas were higher (0.30 ml.m/3) than at the other stations (0.07 ml.m/3). Crustacean eggs, fish eggs and mysids clustered in pockets of abnormally high...

  5. Sea truth validation of sea WiFS ocean colour sensor in the coastal waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S; Suresh, T.; Matondkar, S.G.P.; Desa, E.

    adopted by O?Reilly et al. 5 for pigment alg o rithms, we express Lwn in terms of ?above sea surface? values of Lu (0 + ) and Es (0 + ), using the approximation Lu (0 + ) = 0.544 Lu (0 ? ), where L u (0 ? ) is the ?below sea surface? water... - leaving radiance measured by the profiling rad i ometer, and Es (0 + ) is the measured downwelling irradiance from the reference sky - viewing radiometer above the sea surface. The Lwn definition for any wavelength is: Lwn = F o [ Lu (0...

  6. Thickness of the Descending Philippine Sea Plate Estimated from Tomographic Images beneath the Kumano Basin, along the Nankai Trough, Southwestern Japan

    Science.gov (United States)

    Kamiya, S.; Suzuki, K.; Takahashi, N.

    2015-12-01

    The Philippine Sea plate subducts northwestward beneath the Japanese islands from the south. The average thickness of the overall Philippine Sea plate has been investigated in the oceanic area using surface wave analyses [e.g. Abe and Kanamori, 1970], suggesting a thin (30-40 km thick) plate. On the other hand, several studies have indicated a thicker Philippine Sea plate based on source mechanisms and seismicity in the eastern rim of the plate [Seno, 1987; Moriyama et al., 1989]. From tomographic images, Kamiya and Kobayashi [2007] pointed out that the subducting Philippine Sea slab has thickness variation with a stepwise offset east of Izu Peninsula. The eastern (the Kanto district) and western (north of Izu Peninsula and the Tokai district) regions have respective thicknesses of 60 and 25 km. In the Kumano basin, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) developed the Dense Oceanfloor Network System for Earthquakes and Tsunami (DONET) in order to monitor seismic activity [Kaneda et al., 2009; Kawaguchi et al., 2010]. DONET ocean-bottom stations are connected with an optical fiber cable, and data are transferred in real time to our laboratory at JAMSTEC. The present study obtains three-dimensional P-wave and S-wave seismic velocity models beneath the Kumano basin by employing an travel time tomography technique. We pick arrival times of P and S waves from the waveform data recorded by the DONET system during the period from January 2011 to December 2014. In order to improve the resolution in the deeper regions than the seismic area inside of the descending slab, we also pick arrival times from the seismic events occurred outside of this district. We use these picked arrival times adding to the JMA catalogue data in seismic tomography. From the obtained tomographic images, we find high velocity anomalies corresponding to the descending Philippine Sea slab. We also find low velocity anomalies under the high velocity slab clearly. There

  7. Sea level changes along the Turkish coasts of the Black Sea, the Aegean Sea and the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    B. ALPAR

    2000-06-01

    On the average, there is a pronounced sea-level difference (55 cm along the Turkish Straits System. However, the slope is nonlinear, being much steeper in the Strait of Istanbul. This barotrophic pressure difference is one of the most important factors causing the two-layer flow through the system. The topography and hydrodynamics of the straits, the dominant wind systems and their seasonal variations make this flow more complicated. For secular sea level changes, a rise of 3.2 mm/a was computed for Karsiyaka (1935-71 and a steady trend (-0.4 mm /a has been observed for annual sea levels at Antalya (1935-77. The decreasing trend (-6.9 mm/a at Samsun is contrary to the secular rising trend of the Black Sea probably because of its rather short monitoring period (1963-77.

  8. Addressing Air Pollution and Greenhouse Gas Emissions in the Pan-Japan Sea Region. An Overview of Economic Instruments

    International Nuclear Information System (INIS)

    Boyle, G.; Kambu, A.

    2005-11-01

    The health and environmental impacts of fossil fuel consumption are of increasing concern to countries in the Pan-Japan Sea region, where economic growth has led to increased energy consumption in recent years. Economic instruments like green taxes and emissions-trading schemes represent important tools to help reduce air pollution and greenhouse gas (GHG) emissions in China, Japan, South Korea and Russia. Over the past several years, OECD countries have made progress in the use of economic instruments to reduce atmospheric air pollution. In Europe, new environmental taxes have been used most extensively, while in the United States market creation and emissions-trading schemes are more common. In the Pan-Japan Sea region, there has been considerable experience with pollution charge and levy systems, including the longstanding Japanese sulfur levy and the Russian and Chinese pollution charge systems. Generally, tax and emissions-trading systems are only beginning to emerge in the region although China has been experimenting with SOx emissions-trading schemes for several years now and South Korea and Japan have already begun experimenting with CO2 emissions-trading schemes. Only Japan has seriously looked at a carbon tax to curb GHG emissions among the four countries while direct subsidies for cleaner technologies have been adopted in the different Pan-Japan Sea countries. The costs and benefits of different economic instruments like taxes, charges, emissions-trading schemes and subsidies vary from case to case because they all have to be financially feasible, rest on informed and competent public institutions and perform effectively in local market and economic conditions. On top of all these is the fact that their overall success depends on their political acceptability. Given the experience of Pan-Japan Sea countries with economic instruments so far vis-a-vis the lessons learned in OECD countries and the nature of current and emerging pollution problems in Pan-Japan

  9. Submarine basaltic fountain eruptions in a back-arc basin during the opening of the Japan Sea

    Science.gov (United States)

    Hosoi, Jun; Amano, Kazuo

    2017-11-01

    Basaltic rock generated during the middle Miocene opening of the Japan Sea, is widely distributed on the back-arc side of the Japanese archipelago. Few studies have investigated on submarine volcanism related to opening of the Japan Sea. The present study aimed to reconstruct details of the subaqueous volcanism that formed the back-arc basin basalts (BABB) during this event, and to discuss the relationship between volcanism and the tectonics of back-arc opening, using facies analyses based on field investigation. The study area of the southern Dewa Hills contains well-exposed basalt related to the opening of the Japan Sea. Five types of basaltic rock facies are recognized: (1) coherent basalt, (2) massive platy basalt, (3) jigsaw-fit monomictic basaltic breccia, (4) massive or stratified coarse monomictic basaltic breccia with fluidal clasts, and (5) massive or stratified fine monomictic basaltic breccia. The basaltic rocks are mainly hyaloclastite. Based on facies distributions, we infer that volcanism occurred along fissures developed mainly at the center of the study area. Given that the rocks contain many fluidal clasts, submarine lava fountaining is inferred to have been the dominant eruption style. The basaltic rocks are interpreted as the products of back-arc volcanism that occurred by tensional stress related to opening of the Japan Sea, which drove strong tectonic subsidence and active lava fountain volcanism.

  10. Geological evidence of tsunamis and earthquakes at the Eastern Hellenic Arc: correlation with historical seismicity in the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Gerassimos Papadopoulos

    2012-12-01

    Full Text Available Sedimentary stratigraphy determined by trenching in Dalaman, south-western Turkey, revealed three sand layers at a distance of approximately 240 m from the shoreline and at elevations of +0.30, +0.55 and +0.90 cm. Storm surge action does not explain the features of these deposits that show instead typical characteristics of tsunami deposition. The sand layers correlate with historical tsunamis generated by large earthquakes which ruptured the eastern Hellenic Arc and Trench in 1303, 1481 and 1741. Accelerator mass spectrometry 14C dating of a wood sample from layer II indicated deposition in AD 1473±46, which fits the 1481 event. From an estimated average alluvium deposition rate of approximately 0.13 cm/year, layers I and III were dated at 1322 and 1724, which may represent the large 1303 and 1741 tsunamis. The geological record of the 1303 key event is very poor; therefore, sand layer I perhaps represents an important geological signature of the 1303 tsunami. However, the strong tsunami reported to have been generated by the 1609 earthquake is missing from Dalaman stratigraphy: this underlines the sensitivity of tsunami geological signatures to various local factors. The 1303 earthquake ruptured the trench between the islands of Crete and Rhodes. For the earthquakes of 1481, 1609 and 1741 we suggested that they were very likely generated in the Rhodes Abyssal Plain where sea depths of up to approximately 4200 m, together with the thrust component of seismotectonics, favor tsunami generation. Sand dykes directed upwards from layer I to layer II indicated that the 1481 earthquake triggered liquefaction of sand layer I. The results substantially widen our knowledge about the historical earthquake and tsunami activity in the eastern Mediterranean basin.

  11. Scenario of Methane and Gas Hydrate occurrences in different geological settings in the eastern Mediterranean Sea

    Science.gov (United States)

    Karisiddaiah, S. M.

    2003-04-01

    An attempt is made here to unravel the various types of methane occurrences in the eastern Mediterranean Sea. First part devotes on the occurrence of methane in anoxic brines, in sea water and in the underlying sediments, while the next half concentrates on the significance of methane in the natural gas hydrates with in the sediments under special P-T conditions from mud volcanoes of Anaximander Mountain Ranges and Mediterranean Ridges as reported by various researchers. Very high methane concentrations (128-2692 mM) occur in the hypersaline anoxic brine pools of Bannock and Urania, within the Eastern Mediterranean Sea, compared to its concentrations (17 to 80 m M) in the sediment cores below the anoxic brines. Besides, in the underlying sediments bit higher range in methane (10-158 nM) values occur, compared to low methane (1.47-7.14 nM) concentrations in the overlying water column and the basins surrounding Crete Island. The methane enrichment in the brines might be due to the long residence time of brine in the basin, and to its high stability toward mixing with overlying seawater. Possible sources for this methane enrichment could be a deep source of hydrothermal activities, prevalence of gas hydrate horizons and occurrence of sapropels. Gas hydrate research had reached an astounding position in the earth sciences. The present day situation of natural gases for the entire world caused an alarming strategy to search for new clean fuel energy, such as the one sequestered in the gas hydrates. In this context an attempt is made here to review the significance of gas hydrate occurrences in the eastern Mediterraneans mainly from Anaximander Mountain Range mud volcanoes (which are characterized by a concentric zonal distribution of gas hydrates) and mud volcanoes in Mediterranean Ridges which might be the future sites for gas hydrate exploration.

  12. Observed interannual variability of the thermohaline structure in the south eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Kurian, N.; Costa, J.; Suneel, V.; Gopalakrishna, V.V.; Rao, R.R.; Girish, K.; Amritash, S.; Ravichandran, M.; John, L.; Ravichandran, C.

    Author version: Remote Sensing of the Changing Oceans. Ed. by: Tang, D.Springer, vol.Pt. 4(Chap. 16); 2011; 305-323 Observed interannual variability of the near-surface thermohaline structure in the South Eastern Arabian Sea Nisha Kurian 1 , Joshua... this region intense organised moist convection occurs heralding rapid northward advance of the summer monsoon (Gadgil et al, 1984; Joseph, 1990; Shenoi et al, 1999; Vinayachandran and Shetye, 1991; Rao and Sivakumar, 1999; Shenoi et al 2005). The region off...

  13. Seasonal variability in oxygen and nutrients in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    De; DileepKumar, M.; Sardessai, S.; Sarma, V.V.S.S.; Shirodkar, P.V.

    : JGOFS (INDIA) Seasonal variability in oxygen and nutrients in the central and eastern Arabian Sea S. N. de Sousa, M. Dileep Kumar, S. Sardessai, V. V. S. S. Sarma and P.V. Shirodkar National Institute of Oceanography, Dona Paula, Goa 403 004, India... maximum of 10 ?M in winter, whereas, it was half this value in monsoon. The average deficits suggest increasing reducing conditions in the order monsoon (1.6 ?M), intermonsoon (3.7 ?M) and winter (4.0 ?M). THE Indian Ocean experiences seasonally variable...

  14. New compact ocean bottom cabled seismometer system deployed in the Japan Sea

    Science.gov (United States)

    Shinohara, Masanao; Kanazawa, Toshihiko; Yamada, Tomoaki; Machida, Yuya; Shinbo, Takashi; Sakai, Shin'ichi

    2014-09-01

    The Japanese islands are positioned near the subduction zones, and large earthquakes have repeatedly occurred in marine areas around Japan. However, the number of permanent earthquake observatories in the oceans is quite limited. It is important for understanding generation of large earthquakes to observe seismic activities on the seafloor just above these seismogenic zones. An ocean bottom cabled seismometer (OBCS) is the best solution because data can be collected in real-time. We have developed a new compact OBCS system. A developed system is controlled by a microprocessor, and signals from accelerometers are 24-bit digitized. Clock is delivered from the global positioning system receiver on a landing station using a simple dedicated line. Data collected at each cabled seismometer (CS) are transmitted using standard Internet Protocol to landing stations. The network configuration of the system adopts two dual methods. We installed the first practical OBCS system in the Japan Sea, where large earthquakes occurred in past. The first OBCS system has a total length of 25 km and 4 stations with 5 km interval. Installation was carried out in August 2010. The CSs and single armored optical submarine cable were buried 1 m below the seafloor to avoid a conflict with fishing activity. The data are stored on a landing station and sent to Earthquake Research Institute, University of Tokyo by using the Internet. After the installation, data are being collected continuously. According to burial of the CSs, seismic ambient noises are smaller than those observed on seafloor.

  15. Early Permian intrusions in the Paleozoic sediments of the Eastern North Sea area

    DEFF Research Database (Denmark)

    Clausen, O.R.; Andresen, Katrine Juul; Rasmussen, Jens Andreas

    This study presents the geometry of Paleozoic intrusions in the Skagerrak area located at the northern flank of the Ringkøbing-Fyn High and suggests factors controlling the formation of the intrusions. The intrusions have here been mapped in detail using 3D seismic data. The study area is located...... in the Northern Permian Basin which in the eastern North Sea is separated from the Southern Permian Basin by the Ringkøbing-Fyn High. The Permian basins were initiated during thermal subsidence following a late Carboniferous- early Permian rifting phase associated with extensive igneous activity recorded across...... the entire North Sea Basin. The easternmost intrusions and extrusions have been associated to the “Skagerrak-Centered Large Igneous Province” that has an early Permian age of c. 297 Ma. Compared to the Southern Permian Basin which historically has been intensely investigated because of the known presence...

  16. Sedimentology and geochemistry of mud volcanoes in the Anaximander Mountain Region from the Eastern Mediterranean Sea.

    Science.gov (United States)

    Talas, Ezgi; Duman, Muhammet; Küçüksezgin, Filiz; Brennan, Michael L; Raineault, Nicole A

    2015-06-15

    Investigations carried out on surface sediments collected from the Anaximander mud volcanoes in the Eastern Mediterranean Sea to determine sedimentary and geochemical properties. The sediment grain size distribution and geochemical contents were determined by grain size analysis, organic carbon, carbonate contents and element analysis. The results of element contents were compared to background levels of Earth's crust. The factors that affect element distribution in sediments were calculated by the nine push core samples taken from the surface of mud volcanoes by the E/V Nautilus. The grain size of the samples varies from sand to sandy silt. Enrichment and Contamination factor analysis showed that these analyses can also be used to evaluate of deep sea environmental and source parameters. It is concluded that the biological and cold seep effects are the main drivers of surface sediment characteristics from the Anaximander mud volcanoes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Variations in swells along Eastern Arabian Sea during the summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Johnson, G.; SanilKumar, V.; Sanjiv, P.C.; Singh, J.; Pednekar, P.S.; AshokKumar, K.; Dora, G.U.; Gowthaman, R.

    the average spring tidal range is about 1.8 m and the neap tidal range is 0.9 m. 3. Materials and Methods The waves at 3 locations (Table 1) along the west coast of India in the eastern Arabian Sea were measured using the Datawell directional waverider... and that due to wind sea was 0.9 to 1.1 m. Hm0 up to 4.7 m and Hmax up to 7.4 m was recorded during the meas- urement period. Hm0 was more than 2 m during 40, 50 and 66% of time at Honnavar, Ratnagiri and Muldwarka. Percentage of swell energy in the total...

  18. A new species of Halcampella (Actiniaria, Halcampoididae from the eastern Weddell Sea and Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Estefanía Rodríguez

    2002-03-01

    Full Text Available A new species of soft-bottom-dwelling sea anemone of the genus Halcampella is described and illustrated based on 47 specimens collected during the Polarstern cruises ANT XV/3 and ANT XVII/3 to the Antarctic Peninsula and the eastern Weddell Sea. The new Halcampella species is easily distinguishable from its congeners by the number of cycles of mesenteries and tentacles, the cnidae and the geographic distribution. The new species is described and compared to the available type material of the other species of the genus and new cnidae data are given for H. maxima Hertwig, 1888 and H. robusta Carlgren, 1931. According to other authors H. endromitata (Andres, 1881 is considered a nomen dubium and H. maxima is here proposed as the types species of the genus.

  19. Sensitivity of WRF-ARW for Heavy Precipitation Event over the Eastern Black Sea Region

    Science.gov (United States)

    Doǧan, Onur Hakan; Önol, Barış

    2017-04-01

    In this study, we examined the extreme summer precipitation case over the Eastern Black Sea region of Turkey by using WRF-ARW. 11 people were killed by the flood and many buildings were damaged by the landslides in Artvin province. The flood caused by heavy precipitation between August 23 and 24, 2015 and the station observation is 255 mm total precipitation for the two days. We have also used satellite based observational data (Global Precipitation Measurement: GPM), which represents 150 mm total precipitation during case, to validate precipitation simulations. We designed three nested domains with 27-9-3 km resolutions for the simulations and the inner domain covers the all Black Sea and the surrounded coasts. The simulations have been driven by ECMWF ERA-Interim data and the initial conditions have been generated for 4 different simulations which are 3-days, 7-days, 15-days and 25-days long. WRF-ARW model physics parameters have been tested to improve simulation capability for extreme precipitation events. The microphysics (Kessler and New-Thompson) and PBL (YSU PBL and Mellor-Yamada-Janjic) options have been applied for each simulations separately, therefore 15 sensitivity simulation have been analyzed by using different parametrizations. In general, all simulations underestimated the two days extreme precipitation event which the large scale flow interact with warmer sea surface temperatures and complex topography over the eastern Black Sea region. The 3-days simulation with Kessler microphysics and YSU PBL predicts 148 mm precipitation which is highest simulated precipitation compare to all simulations for the corresponding station location. Moreover 25-days simulation represents better spatial coverage for precipitation pattern compare to the GPM data.

  20. A new sketch of the central North Banda Sea, Eastern Indonesia

    Science.gov (United States)

    Réhault, J. P.; Malod, J. A.; Larue, M.; Burhanuddinn, S.; Sarmili, L.

    The North Banda Sea (Eastern Indonesia) is an oceanic domain whose origin is controversial. New bathymetric and seismic reflection profiles, in addition to those published previously, allow presentation of a new bathymetric map and structural sketch of this basin. A general NW-SE structural pattern appears to be the result of: first, the orientation of very large NW-SE strike-slip faults. Among them the West Baru fracture zone is described for the first time and can be traced for about 300 km; second, the present direction of convergence seems to be oriented NE-SW. This has resulted in the faulting and underthrusting of the Banda Sea crust beneath the East Sulawesi margin, particularly well expressed in the north. As a consequence of the convergence along the Tolo Thrust an active accretionary prism is developed and a peripheral bulge arches the central domain of the North Banda Sea. The nature of the North Banda Sea floor is still unknown but several good dredging sites are identified to solve this major problem in the region.

  1. Response of benthic foraminifera to phytodetritus in the eastern Arabian Sea under low oxygen conditions

    Science.gov (United States)

    Enge, Annekatrin; Wukovits, Julia; Wanek, Wolfgang; Watzka, Margarete; Witte, Ursula; Hunter, William; Heinz, Petra

    2016-04-01

    At water depths between 100 and 1500 m a permanent Oxygen Minimum Zone (OMZ) impinges on the sea floor in the eastern Arabian Sea, exposing benthic organisms to anoxic to suboxic conditions. The flux of organic matter to the sea floor is relatively high at these depths but displays seasonal variation. Deposition of relatively fresh phytodetrital material (phytoplankton remains) can occur within a short period of time after monsoon periods. Several organism groups including foraminifera are involved to different extent in the processing of phytodetritus in the OMZs of the northern Arabian Sea. A series of in situ feeding experiments were performed to study the short-term processing (metabolic processes under hypoxic stress. Variable levels and ratios of phytodetrital carbon and nitrogen indicate specific nutritional demands and storage of food-derived nitrogen in some foraminifera species under near anoxia where the mean phytodetrital nitrogen content in foraminifera was elevated. In summary, foraminifera dominate the short-term processing of phytodetritus by fauna in the OMZ core but are less important in the lower OMZ boundary region of the Indian margin as a result of biological interactions and changes in the distribution of individual foraminiferal species.

  2. Trophic ecology of deep-sea Asteroidea (Echinodermata) from eastern Canada

    Science.gov (United States)

    Gale, Katie S. P.; Hamel, Jean-François; Mercier, Annie

    2013-10-01

    Asteroids (sea stars) can be important predators in benthic communities and are often present in ecologically important and vulnerable deep-sea coral and sponge habitats. However, explicit studies on the trophic ecology of deep-sea asteroids are rare. We investigated the diets of seven species of deep-sea asteroid from the bathyal zone of Newfoundland and Labrador, eastern Canada. A multifaceted approach including live animal observations, stomach content analysis, and stable isotope analysis revealed the asteroids to be either top predators of megafauna or secondary consumers (mud ingesters, infaunal predators, and suspension feeders). The stable isotope signatures of Ceramaster granularis, Hippasteria phrygiana, and Mediaster bairdi are characteristic of high-level predators, having δ15N values 4.4‰ (more than one trophic level) above Ctenodiscus crispatus, Leptychaster arcticus, Novodinia americana, and Zoroaster fulgens. We present strong evidence that corals and sponges are common food items for two of the predatory species, C. granularis and H. phrygiana. During laboratory feeding trials, live H. phrygiana fed on several species of soft coral and C. granularis fed on sponges. Stomach content analysis of wild-caught individuals revealed sclerites from sea pens (e.g. Pennatula sp.) in the stomachs of both asteroid species; H. phrygiana also contained sclerites from at least two other species of octocoral and siliceous sponge spicules were present in the stomachs of C. granularis. The stomach contents of the secondary consumers contained a range of invertebrate material. Leptychaster arcticus and Ctenodiscus crispatus feed infaunally on bulk sediment and molluscs, Zoroaster fulgens is a generalist infaunal predator, and the brisingid Novodinia americana is a specialist suspension feeder on benthopelagic crustaceans. This study provides a foundation for understanding the ecological roles of bathyal asteroids, and suggests that some species may have the

  3. Seasonal variation of radon daughters concentrations in the atmosphere and in precipitation at the Japanese coast of the Sea of Japan

    International Nuclear Information System (INIS)

    Nishikawa, T.; Okabe, S.; Aoki, M.

    1988-01-01

    The atmospheric radon daughters concentration at Fukui in the Japanese coastal region of the Sea of Japan shows a seasonal variation whose high values appear in summer and low values in winter. On the other hand, the radon daughters concentration in precipitation at Fukui and that in the maritime atmosphere over the Sea of Japan are high in winter and low in summer. It is concluded from these phenomena that the greater part of the continental radon and its daughters are transported by seasonal winds from Siberia and China to Japan across the Sea of Japan in winter. However, when the air masses approach the shore, the cumulonimbus grows and the heavy snowfall scavenges out the radon daughters from the air masses in large quantities at the Japanese coastal region of the Sea of Japan. (author)

  4. Radioactive contamination of the Arctic Region, Baltic Sea, and the Sea of Japan from activities in the former Soviet Union

    International Nuclear Information System (INIS)

    Bradley, D.J.

    1992-09-01

    Contamination of the Arctic regions of northern Europe and Russia, as well as the Sea of Japan, may become a potential major hazard to the ecosystem of these large areas. Widespread poor radioactive waste management practices from nuclear fuel cycle activities in the former Soviet Union have resulted in direct discharges to this area as well as multiple sources that may continue to release additional radioactivity. Information on the discharges of radioactive materials has become more commonplace in the last year, and a clearer picture is emerging of the scale of the contamination. Radioactivity in the Arctic oceans is now reported to be four times higher than would be derived from fallout from weapons tests. Although the characteristics and extent of the contamination are not well known, it has been stated that the contamination in the Arctic may range from 1 to 3.5 billion curies. As yet, no scientific sampling or measurement program has occurred that can verify the amount or extent of the contamination, or its potential impact on the ecosystem

  5. The History of Research and Development Islands Peter the Great Bay, Sea of Japan

    Directory of Open Access Journals (Sweden)

    Aleksandr B. Kosolapov

    2016-06-01

    Full Text Available The article discusses the history of the discovery, research and development of the islands of Russian pioneers in Peter the Great Bay, Sea of Japan from the middle of the XIX century. The paper used in scientific papers and journalistic materials researchers Islands Peter the Great Bay, unpublished sources: Russian State Historical Archive of the Far East, Primorsky Region State Archives, Archives of Primorsky regional department of the All-Russian public organization "Russian Geographical Society" Society for the Study of the Amur region. The methodological basis of the work was the principle of historicism and objectivity, allowed to consider the issue of research and development of the islands of the Gulf of Peter the Great on a broad documentary basis in the process of development in the specific historical conditions. The history of hydrographic discoveries of natural and geographical studies. It touches upon the issues concerning the construction of Vladivostok fortress. In the periodical press materials recreated pages agricultural and industrial development of the islands. Examples of business entrepreneurs first edge (A.D. Startsev, M.I. Jankowski, O.V. Lindgolm. The Toponymic notes link the island territories with the names of their discoverers, explorers, industrialists. The authors conclude that the historical conditionality of development of the islands is linked mainly with the military interests of Russia on its southeastern edge, using the resources of the sea and the unique natural conditions suitable for the development of agricultural, industrial, recreation and tourism.

  6. Historical δ15N records of Saccharina specimens from oligotrophic waters of Japan Sea (Hokkaido)

    Science.gov (United States)

    Kuribayashi, Takanori; Abe, Tsuyoshi; Montani, Shigeru

    2017-01-01

    Historically Saccharina spp. beds occurred along the west coast of Hokkaido, an oligotrophic area, and were commercially exploited. Currently extensive commercial Saccharina spp. beds do not form due to nutrient limitations. Here, we postulate that nutrients assimilated by paleo-Saccharina spp. beds may have been derived from spawning herrings (Clupea pallasii) acting as organisms that formed a vector from their feeding grounds (Okhotsk Sea and Pacific Ocean) to their spawning area (west coast of Hokkaido, Japan Sea). To test this hypothesis we examined stable nitrogen isotope ratios (δ15N) of 100– to 135–year-old Saccharina specimens preserved at the Herbarium (Hokkaido University Museum). δ15N values of the paleo-Saccharina specimens collected from this region were in the range of 10‰, which is significantly higher than the current 3–7‰ in freshly sampled Saccharina spp. This high δ15N indicates that spawning herring (Clupea pallasii) had potentially been a significant source of dissolved inorganic nitrogen (DIN) absorbed by Saccharina, acting as an organism forming a vector for transporting nutrients from eutrophic to oligotrophic coastal ecosystems. Our findings support the hypothesis of so-called “herring-derived nutrients.” PMID:28704453

  7. Submarine canyons as coral and sponge habitat on the eastern Bering Sea slope

    Directory of Open Access Journals (Sweden)

    Robert J. Miller

    2015-07-01

    Full Text Available Submarine canyons have been shown to positively influence pelagic and benthic biodiversity and ecosystem function. In the eastern Bering Sea, several immense canyons lie under the highly productive “green belt” along the continental slope. Two of these, Pribilof and Zhemchug canyons, are the focus of current conservation interest. We used a maximum entropy modeling approach to evaluate the importance of these two canyons, as well as canyons in general, as habitat for gorgonian (alcyonacean corals, pennatulacean corals, and sponges, in an area comprising most of the eastern Bering Sea slope and outer shelf. These invertebrates create physical structure that is a preferred habitat for many mobile species, including commercially important fish and invertebrates. We show that Pribilof canyon is a hotspot of structure-forming invertebrate habitat, containing over 50% of estimated high-quality gorgonian habitat and 45% of sponge habitat, despite making up only 1.7% of the total study area. The amount of quality habitat for gorgonians and sponges varied in other canyons, but canyons overall contained more high-quality habitat for structure-forming invertebrates compared to other slope areas. Bottom trawling effort was not well correlated with habitat quality for structure-forming invertebrates, and bottom-contact fishing effort in general, including longlining and trawling, was not particularly concentrated in the canyons examined. These results suggest that if conserving gorgonian coral habitat is a management goal, canyons, particularly Pribilof Canyon, may be a prime location to do this without excessive impact on fisheries.

  8. Novel active kinetoplastids associated with hypersaline anoxic basins in the Eastern Mediterranean deep-sea

    Science.gov (United States)

    Edgcomb, V. P.; Orsi, W.; Breiner, H.-W.; Stock, A.; Filker, S.; Yakimov, M. M.; Stoeck, T.

    2011-10-01

    The combination of nearly saturated salt concentration and corresponding high density, high hydrostatic pressure, absence of light, anoxia, and a sharp chemocline make the deep hypersaline anoxic basins in the Eastern Mediterranean Sea some of the most polyextreme habitats on Earth. Using kinetoplastid-specific primers, we detected kinetoplastid flagellates in some of the harshest deep-sea environments known to date, including some whose small subunit ribosomal RNA gene sequences are not closely related to cultured representatives. Kinetoplastids, including presumably novel representatives appear to be specialists of halocline environments in the Eastern Mediterranean, and to comprise a significant fraction of the protist communities in the brines and haloclines of several basins. Fluorescent in situ hybridization data indicate a novel 'unidentified' sequence clade of kinetoplastids related to bodonids represents as much as 10% of the total protist community in the Discovery Basin halocline. Different kinetoplastid groups are unevenly represented in the different basins and habitats we sampled, which we discuss as a result of environmental selection.

  9. An Evaluation of Vanadium Enrichment in the Eastern Shelf Sediments of the Turkish Black Sea

    Directory of Open Access Journals (Sweden)

    Selma Ünlü

    2017-05-01

    Full Text Available This paper presents an evaluation of the spatial distribution of vanadium level, its enrichment and possible sources in the bottom sediment along the shelf of the Turkish Black Sea. In April 2006, vanadium concentrations were measured along the measurement profiles (20, 50 and 100 m using ICP-MS. The vanadium levels ranged from 40 to 315 µg g-1, usually within the range of typical and background values (Cf3. The concentrations decrease gradually with water depth, implying the dominance of anthropogenic sources such as industrial wastes, agricultural effluents, sewage discharge, and port activities. The vanadium levels had not significant correlations with the physicochemical parameters (sediment texture, water content, TOC and TPH level in the sediment. At the eastern basin, a serious vanadium enrichment (Cf>6-9 was observed in November 2010, implying some important regional and seasonal contributions; which may be natural or anthropogenic. Biogeochemical processes, eutrophication, wave-based erosion, abnormal current circulations, bottom morphology and influence of other substances in the environment may be other regulating factors to this enrichment. Continuous monitoring and further studies are required for a detailed description of vanadium mobility and for assessment of the main controlling processes associated with vanadium enrichment in the eastern Black Sea basin.

  10. Sea-floor geology and topography offshore in Eastern Long Island Sound

    Science.gov (United States)

    Poppe, L.J.; McMullen, K.Y.; Ackerman, S.D.; Blackwood, D.S.; Schaer, J.D.; Forrest, M.R.; Ostapenko, A.J.; Doran, E.F.

    2011-01-01

    A gridded multibeam bathymetric dataset covers approximately 133.7 square kilometers of sea floor offshore in eastern Long Island Sound. Although originally collected for charting purposes during National Oceanic and Atmospheric Administration hydrographic survey H11997, these acoustic data, and the sea-floor sampling and photography stations subsequently occupied to verify them during USGS cruise 2010-015-FA, are part of an expanding series of studies that provide a fundamental framework for research and resource management (for example, cables, pipelines, and dredging) activities in this major East Coast estuary. Results show the composition and terrain of the seabed and provide information on sediment transport and benthic habitat. Bedrock outcrops, erosional outliers, lag deposits of boulders, scour depressions, and extensive gravel pavements are common in the eastern part of the study area. These features, which result from the near-constant exposure to strong tidal currents, indicate sedimentary environments dominated by processes associated with erosion. Large fields of transverse and barchanoid sand waves in the western part of the study area reflect slightly lower energy levels and sedimentary environments where processes associated with coarse bedload transport prevail.

  11. Coastal Sea Level along the North Eastern Atlantic Shelf from Delay Doppler Altimetry

    Science.gov (United States)

    Fenoglio-Marc, L.; Benveniste, J.; Andersen, O. B.; Gravelle, M.; Dinardo, S.; Uebbing, B.; Scharroo, R.; Kusche, J.; Kern, M.; Buchhaupt, C.

    2017-12-01

    Satellite altimetry data of the CryoSat-2 and Sentinel-3 missions processed with Delay Doppler methodology (DDA) provide improved coastal sea level measurements up to 2-4 km from coast, thanks to an along-track resolution of about 300m and a higher signal to noise ratio. We investigate the 10 Kilometre stripe along the North-Eastern Atlantic shelf from Lisbon to Bergen to detect the possible impacts in sea level change studies of this enhanced dataset. We consider SAR CryoSat-2 and Sentinel-3 altimetry products from the ESA GPOD processor and in-house reduced SAR altimetry (RDSAR) products. Improved processing includes in RDSAR the application of enhanced retrackers for the RDSAR waveform. Improved processing in SAR includes modification both in the generation of SAR waveforms, (as Hamming weighting window on the burst data prior to the azimuth FFT, zero-padding prior to the range FFT, doubling of the extension for the radar range swath) and in the SAMOSA2 retracker. Data cover the full lifetime of CryoSat-2 (6 years) and Sentinel-3 (1 year). Conventional altimetry are from the sea level CCI database. First we analyse the impact of these SAR altimeter data on the sea level trend and on the estimation of vertical motion from the altimeter minus tide gauge differences. VLM along the North-Eastern Atlantic shelf is generally small compared to the North-Western Atlantic Coast VLM, with a smaller signal to noise ratio. Second we investigate impact on the coastal mean sea level surface and the mean dynamic topography. We evaluate a mean surface from the new altimeter data to be combined to state of the art geoid models to derive the mean dynamic topography. We compare the results to existing oceanographic and geodetic mean dynamic topography solutions, both on grid and pointwise at the tide gauge stations. This study is supported by ESA through the Sea Level CCI and the GOCE++DYCOT projects

  12. Tracking Dissolved Methane Concentrations near Active Seeps and Gas Hydrates: Sea of Japan.

    Science.gov (United States)

    Snyder, G. T.; Aoki, S.; Matsumoto, R.; Tomaru, H.; Owari, S.; Nakajima, R.; Doolittle, D. F.; Brant, B.

    2015-12-01

    A number of regions in the Sea of Japan are known for active gas venting and for gas hydrate exposures on the sea floor. In this investigation we employed several gas sensors mounted on a ROV in order to determine the concentrations of dissolved methane in the water near these sites. Methane concentrations were determined during two-second intervals throughout each ROV deployment during the cruise. The methane sensor deployments were coupled with seawater sampling using Niskin bottles. Dissolved gas concentrations were later measured using gas chromatography in order to compare with the sensor results taken at the same time. The observed maximum dissolved methane concentrations were much lower than saturation values, even when the ROV manipulators were in contact with gas hydrate. Nonetheless, dissolved concentrations did reach several thousands of nmol/L near gas hydrate exposures and gas bubbles, more than two orders of magnitude over the instrumental detection limits. Most of the sensors tested were able to detect dissolved methane concentrations as low as 10 nmol/L which permitted detection when the ROV approached methane plume sites, even from several tens of meters above the sea floor. Despite the low detection limits, the methane sensors showed variable response times when returning to low-background seawater (~5nM). For some of the sensors, the response time necessary to return to background values occurred in a matter of minutes, while for others it took several hours. Response time, as well as detection limit, should be an important consideration when selecting methane sensors for ROV or AUV investigations. This research was made possible, in part, through funding provided by the Japanese Ministry of Economy, Trade and Industry (METI).

  13. Radiocesium distribution on sea sediment and in benthic organisms in the north-east Japan coast

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Tsuneo; Ambe, Daisuke; Kaeriyama, Hideki; Shigenobu, Yuya; Fujimoto, Ken; Saito, Hajime; Miki, Shiduho; Setou, Takashi; Morita, Takami; Watanabe, Tomowo [National Research Institute of Fisheries Sciences, Fisheries Research Agency, 2-12-4, Fukuura, Kanazawaward, Yokohama, Kanagawa, 236-8648 (Japan); Sawada, Hideki [National Resarch Institute of Fisheries Engineering, Fisheries Research Agency, 7620-7, Hasaki, Kamisu-shi, Ibaraki, 314-0408 (Japan)

    2014-07-01

    A large amount of radioactive materials, especially radiocesium, were discharged into the western North Pacific Ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster following the Great East Japan Earthquake and tsunami on 11 March 2011. Although radiocesium concentrations in sea water had quickly diminished via water mixing processes, significant amount still existed on sea floors near Fukushima Prefecture. To assess present distributions and/or spatio-temporal variations of sea sediment radiocesium and its potential affection to benthic ecosystems, we had conducted 5'x5' 2-D observation of sea sediment radiocesium concentrations repeatedly from Feb. 2012 to Jul. 2013. Off Fukushima Prefecture, the higher concentration area of radioactive cesium was often observed in the south area from the FDNPP and a north-south high value band was tended to be along the isobaths around 100 m where the concentration values up to thousands Bq/kg-dry order were observed. The concentrations generally decreased eastward from the high concentration band. At many surveyed positions, the vertical profiles of the radiocesium concentrations in sea sediment showed an exponentially decreasing in deeper layer. The influence of the FDNPP was suggested to generally reach up to 10 cm depth from sediment-surface. A negative correlation was found between the radiocesium concentration and median grain size of the sediment, suggesting that the adsorption capability of sediment for cesium associated with grain size possibly has a large contribution to the formation process of the spatial distribution pattern of the radiocesium concentration. In contrast to the land sediment, Chemical reaching experiment results showed that the radiocesium concentration in the organic component of bottom sediment has higher value than that of bulk sediment, suggesting that non-exchangeable adsorption cite of mineral component of marine sediments had already occupied by stable cesium (~2 nM in

  14. Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr

    Directory of Open Access Journals (Sweden)

    C. V. Dylmer

    2013-07-01

    Full Text Available Three marine sediment cores distributed along the Norwegian (MD95-2011, Barents Sea (JM09-KA11-GC, and Svalbard (HH11-134-BC continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set of coccolith proxies: the abundance ratio between Emiliania huxleyi and Coccolithus pelagicus, an index of Atlantic vs. Polar/Arctic surface water masses; and Gephyrocapsa muellerae, a drifted coccolith species from the temperate North Atlantic, whose abundance changes are related to variations in the strength of the North Atlantic Current. The entire investigated area, from 66 to 77° N, was affected by an overall increase in AW flow from 3000 cal yr BP (before present to the present. The long-term modulation of westerlies' strength and location, which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO, is thought to explain the observed dynamics of poleward AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic front between the area off western Norway and the western Barents Sea–eastern Fram Strait region. The Little Ice Age (LIA was governed by deteriorating conditions, with Arctic/Polar waters dominating in the surface off western Svalbard and western Barents Sea, possibly associated with both severe sea ice conditions and a strongly reduced AW strength. A sudden short pulse of resumed high WSC (West Spitsbergen Current flow interrupted this cold spell in eastern Fram Strait from 330 to 410 cal yr BP. Our dataset not only confirms the high amplitude warming of surface waters at the turn of the 19th century off western Svalbard, it also shows that such a warming was primarily induced by an excess flow of AW which stands as unprecedented over the last 3000 yr.

  15. Outer shelf seafloor geomorphology along a carbonate escarpment: The eastern Malta Plateau, Mediterranean Sea

    Science.gov (United States)

    Micallef, Aaron; Georgiopoulou, Aggeliki; Mountjoy, Joshu; Huvenne, Veerle A. I.; Iacono, Claudio Lo; Le Bas, Timothy; Del Carlo, Paola; Otero, Daniel Cunarro

    2016-12-01

    Submarine carbonate escarpments, documented in numerous sites around the world, consist of thick exposures of Mesozoic shallow water carbonate sequences - primarily limestones and dolomites - with reliefs of >1 km and slope gradients of >70°. Whilst most research efforts have focused on the processes that shaped carbonate escarpments into complex and extreme terrains, little attention has been paid to the geomorphology of shelves upslope of carbonate escarpments. In this study we investigate high resolution geophysical, sedimentological and visual data acquired from the eastern Malta Plateau, central Mediterranean Sea, to demonstrate that the outer shelf of a carbonate escarpment is directly influenced by escarpment-forming processes. We document forty eight erosional scars, six long channels and numerous smaller-scale channels, three elongate mounds, and an elongate ridge across the eastern Malta Plateau. By analysing their morphology, seismic character, and sedimentological properties, we infer that the seafloor of the eastern Malta Plateau has been modified by three key processes: (i) Mass movements - in the form of translational slides, spreading and debris flows - that mobilised stratified Plio-Pleistocene hemipelagic mud along the shelf break and that were likely triggered by seismicity and loss of support due to canyon erosion across the upper Malta Escarpment; (ii) NNW-SSE trending sinistral strike-slip deformation in Cenozoic carbonates - resulting from the development of a mega-hinge fault system along the Malta Escarpment since the Late Mesozoic, and SE-NW directed horizontal shortening since the Late Miocene - which gave rise to NW-SE oriented extensional grabens and a NNW-SSE horst; (iii) Flow of bottom currents perpendicular and parallel to the Malta Escarpment, associated with either Modified Atlantic Water flows during sea level lowstands and/or Levantine Intermediate Water flows at present, which was responsible for sediment erosion and deposition

  16. Seasonal dynamics of sea surface salinity off Panama: The far Eastern Pacific Fresh Pool

    Science.gov (United States)

    Alory, GaëL.; Maes, Christophe; Delcroix, Thierry; Reul, Nicolas; Illig, Serena

    2012-04-01

    The freshest surface waters in the tropical Pacific are found at its eastern boundary. Using in situ observations, we depict the quasi-permanent presence of a far eastern Pacific fresh pool with sea surface salinity (SSS) lower than 33, which is confined between Panama's west coast and 85°W in December and extends westward to 95°W in April. Strong SSS fronts are found at the outer edge of this fresh pool. We investigate the seasonal dynamics of the fresh pool using complementary satellite wind, rain, sea level and in situ oceanic current data at the surface, along with hydrographic profiles. The fresh pool appears off Panama due to the strong summer rains associated with the northward migration of the ITCZ over Central America in June. During the second half of the year, the eastward-flowing North Equatorial Counter-Current keeps it trapped to the coast and strengthens the SSS front on its western edge. During winter, as the ITCZ moves southward, the northeasterly Panama gap wind creates a southwestward jet-like current in its path with a dipole of Ekman pumping/eddies on its flanks. As a result, upwelling in the Panama Bight brings to the surface cold and salty waters which erode the fresh pool on its eastern side while both the jet current and the enhanced South Equatorial Current stretch the fresh pool westward until it nearly disappears in May. New SMOS satellite SSS data proves able to capture the main seasonal features of the fresh pool and monitor its spatial extent.

  17. Evolution of productivity and monsoonal dynamics in the eastern Arabian Sea during the past 68 ka using dinoflagellate cyst records

    Digital Repository Service at National Institute of Oceanography (India)

    Narale, D.D.; Naidu, P.D.; Anil, A.C.; Godad, S.P.

    of the Arabian Sea. The present-day climatic and oceanographic conditions predominating in the Eastern Arabian Sea (EAS) are influenced by both the South West (SW or summer) and North East (NE or winter) monsoon systems. The EAS experiences moderate upwelling... based on published morphological descriptions (Fensome et al., 1993; Zonneveld, 1997b; Lewis et al., 1999; Matsuoka and Fukuyo, 2000; Rochon et al., 2009; Radi et al., 2013) and modern dinoflagellate cyst determination key by Zonneveld and Pospelova...

  18. Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic

    Directory of Open Access Journals (Sweden)

    S. GARCIA-SANZ

    2014-03-01

    Full Text Available Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula at Gran Canaria Island (eastern Atlantic via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula with the most conspicuous species (D. africanum in the study area.

  19. Assimilation of ocean colour data into a Biogeochemical Flux Model of the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. Triantafyllou

    2007-08-01

    Full Text Available An advanced multivariate sequential data assimilation system has been implemented within the framework of the European MFSTEP project to fit a three-dimensional biogeochemical model of the Eastern Mediterranean to satellite chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS. The physics are described by the Princeton Ocean Model (POM while the biochemistry of the ecosystem is tackled with the Biogeochemical Flux Model (BFM. The assimilation scheme is based on the Singular Evolutive Extended Kalman (SEEK filter, in which the error statistics were parameterized by means of a suitable set of Empirical Orthogonal Functions (EOFs. To avoid spurious long-range correlations associated with the limited number of EOFs, the filter covariance matrix was given compact support through a radius of influence around every data point location. Hindcast experiments were performed for one year over 1999 and forced with ECMWF 6 h atmospheric fields. The solution of the assimilation system was evaluated against the assimilated data and the MedAtlas climatology, and by assessing the impact of the assimilation on non-observed biogeochemical processes. It is found that the assimilation of SeaWiFS data improves the overall behavior of the BFM model and efficiently removes long term biases from the model despite some difficulties during the spring bloom period. Results, however, suggest the need of subsurface data to enhance the estimation of the ecosystem variables in the deep layers.

  20. Sea-Surface Temperatures in the Eastern Equatorial Pacific and Surface Temperatures in the Eastern Cordillera of Colombia during El Niño: Implications for Pliocene Conditions

    Science.gov (United States)

    Pérez-Angel, L. C.; Molnar, P. H.

    2017-12-01

    Regressions of surface temperatures in the Eastern Cordillera of Colombia with sea-surface temperatures (SSTs) in the equatorial Pacific, and specifically with Niño1+2 and Niño3 temperature anomalies, show that the Eastern Cordillera warms or cools by half of the amplitude of the variation in the eastern Tropical Pacific. Because Pliocene SSTs in the eastern Tropical Pacific resemble those during major El Niño events, when SSTs warm by 4°C, these regressions suggest that the Pliocene Eastern Cordillera was possibly warmer by 2ºC at high elevations. Such post-Pliocene cooling is smaller than the 9-12ºC inferred from fossil pollen assemblages, but comparable to recent estimates of Anderson et al. of 3 ± 1ºC (1σ) since 8 Ma. This change in surface temperature could be explained by a change in regional climate associated with a different tropical Pacific SST distribution, and therefore would require neither an elevation change of the Eastern Cordillera since that time, nor a change between Pliocene and present-day temperatures in the tropics that is as large as estimates of the global change of 2.5-4°C.

  1. Sea Surface Temperatures in the Eastern Equatorial Pacific and Surface Temperatures in the Eastern Cordillera of Colombia During El Niño: Implications for Pliocene Conditions

    Science.gov (United States)

    Pérez-Angel, Lina C.; Molnar, Peter

    2017-11-01

    Regressions of surface temperatures in the Eastern Cordillera of Colombia with sea surface temperatures (SSTs) in the equatorial Pacific, and specifically with Niño1+2 and Niño3 temperature anomalies, show that the Eastern Cordillera warms or cools by approximately half of the amplitude of the variation of SSTs in the eastern tropical Pacific. Because Pliocene SSTs in the eastern tropical Pacific resemble those during major El Niño events, when SSTs warm by 4°C, these regressions suggest that the Pliocene Eastern Cordillera was warmer by 2°C at both high and low elevations. Such post-Pliocene cooling is smaller than the 9-12°C inferred from fossil pollen assemblages, but comparable to recent estimates of Anderson et al. of 3 ± 1°C (1σ) since 8 Ma. This change in surface temperature could be explained by a change in regional climate associated with a different tropical Pacific SST distribution and therefore would require neither an elevation change of the Eastern Cordillera since that time nor a change between Pliocene and present-day temperatures in the tropics that is as large as estimates of the global change of 2.5-4°C.

  2. Integrated survey of elemental stoichiometry (C, N, P from the western to eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    M. Pujo-Pay

    2011-04-01

    Full Text Available This paper provides an extensive vertical and longitudinal description of the biogeochemistry along an East-West transect of 3000 km across the Mediterranean Sea during summer 2008 (BOUM cruise. During this period of strong stratification, the distribution of nutrients, particulate and dissolved organic carbon (DOC, nitrogen (DON and phosphorus (DOP were examined to produce a detailed spatial and vertically extended description of the elemental stoichiometry of the Mediterranean Sea. Surface waters were depleted in nutrients and the thickness of this depleted layer increased towards the East from about 10 m in the Gulf of Lion to more than 100 m in the Levantine basin, with the phosphacline deepening to a greater extent than that for corresponding nitracline and thermocline depths. We used the minimum oxygen concentration through the water column in combination with 2 fixed concentrations of dissolved oxygen to distinguish an intermediate layer (Mineralization Layer; ML from surface (Biogenic Layer; BL, and deep layers (DL. Whilst each layer was represented by different water masses, this approach allowed us to propose a schematic box-plot representation of the biogeochemical functioning of the two Mediterranean basins. Despite the increasing oligotrophic nature and the degree of P-depletion along the West to East gradient strong similarities were encountered between eastern and western ecosystems. Within the BL, the C:N:P ratios in all pools largely exceeded the Redfield ratios, but surprisingly, the nitrate vs. phosphate ratios in the ML and DL tended towards the canonical Redfield values in both basins. A change in particulate matter composition has been identified by a C increase relative to N and P along the whole water column in the western basin and between BL and ML in the eastern one. Our data showed a noticeable stability of the DOC:DON ratio (12–13 throughout the Mediterranean Sea. This is in good agreement with a P-limitation of

  3. Opportunism on the High Seas: Foraging Ecology of Olive Ridley Turtles in the Eastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Lindsey E. Peavey

    2017-11-01

    Full Text Available Stable isotopic compositions in animal tissues have been widely used to gain insight into trophic dynamics, especially of mobile aquatic predators whose behavior and dietary preferences are difficult to directly measure. Olive ridley sea turtles (Lepidochelys olivacea range across >3 million km2 of the tropical and subtropical eastern Pacific Ocean and their trophic ecology in open ocean areas has not yet been adequately described. Individuals feed within biogeographic regions where varying nutrient cycling regimes result in phytoplankton with distinct δ13C and δ15N values that are assimilated by the turtles. We sampled 346 turtles at-sea between 2003 and 2009 and used bulk tissue (n = 346 and amino acid compound specific isotope analysis (AA-CSIA, n = 31 to empirically support the conventional understanding that olive ridleys are omnivores. Bulk δ15N values did not significantly vary with carapace length, a proxy for age, or with putative sex of adults. We therefore hypothesize that trophic position (TP does not vary across age or sex. In line with other isotopic studies of this biogeographic scale in the same region, we observed a trend of bulk tissue 15N enrichment with increasing latitude. Using AA-CSIA to account for δ15N baseline shifts among food webs (space, we estimated the TP of adult foragers using two methods. We found that across their eastern Pacific range, olive ridley δ13C and δ15N niche area varied, but median TP of adults remained constant (~3.1. Using a two-amino acid TP estimation method, we detected a small but notable elevation of TP for olive ridleys on the Costa Rica Dome. This study underscores the value of large-scale in-water olive ridley sea turtle research across oceanic foraging habitats to confirm or challenge anecdotal understanding of trophic roles, susceptibility to environmental change, and critical habitats. Further, it improves our understanding of why this species is now abundant in the eastern Pacific

  4. [Determination of hepatitis C virus genotypes among hepatitis C patients in Eastern Black Sea Region, Turkey].

    Science.gov (United States)

    Buruk, Celal Kurtuluş; Bayramoğlu, Gülçin; Reis, Ahu; Kaklıkkaya, Neşe; Tosun, Ilknur; Aydın, Faruk

    2013-10-01

    Hepatitis C virus (HCV), the major cause of transfusion-associated hepatitis, is an important public health problem in the world as well as in Turkey. HCV is grouped as six distinct genotypes and a large number of closely-related subtypes. Genotyping of HCV is an important tool for providing epidemiological data, prediction of prognosis, and optimization of antiviral therapy. This study was carried out to determine the distribution of HCV genotypes in hepatitis C patients residing in different provinces of the Eastern Black Sea Region, Turkey. A total of 304 HCV-RNA positive cases (151 male, 153 female; age range: 11-93 years, mean age: 55.2 ± 13.3 years) who were admitted to the Molecular Microbiology Unit of Department of Medical Microbiology, Karadeniz Technical University Faculty of Medicine, between January 2009 to December 2012, were included in the study. HCV genotypes were detected in plasma samples of the patients by using commercial assays [INNO-LiPA HCV II (Innogenetics, Belgium) or Abbott RealTime HCV Genotype II (Abbott Molecular Inc, USA)]. Due to the ambiguous genotyping results in some samples with these methods, an in-house multiplex polymerase chain reaction (PCR) assay with genotype-specific primers was also used in the study. Similar to the previous reports from Turkey, our results showed that four HCV genotypes (1, 2, 3, and 4) prevailed in the Eastern Black Sea Region and the predominant genotype and subtype were genotype 1 (92.8%) and 1b (87.5%), respectively. Distribution of genotypes were observed to vary according to the province. Prevalences of subtype 1a, genotype 2, 3, and 4 were noted as 5.3%, 1.6%, 4.9%, and 0.7%, respectively. Furthermore, the samples from Giresun, Gumushane and Bayburt provinces, which are relatively less immigrated, had higher genotype 1, and the prevalence rates in the region was affected by the presence of non-citizen residents. This study is the first report on distribution of HCV genotypes in chronic hepatitis

  5. Toxoplasmosis in the Eastern Grey Kangaroo, Macropus giganteus and the Cape Hyrax, Procavis capensis in Japan

    Directory of Open Access Journals (Sweden)

    Khaled Mohamed El-Dakhly1,4, Nagwan El-Habashi2, El-Shaymaa El-Nahass3,4, Hiroki Sakai4 and Tokuma Yanai4,*

    2013-11-01

    Full Text Available Toxoplasmosis was investigated in an eastern grey kangaroo, Macropus giganteus, and four cape hyraxes, Procavia capensis, in a Japanese zoo. Clinically, the kangaroo showed neurological signs, emaciation, diarrhea, elevated AST and CK, and subjected to coma before death. One young cape hyrax had severe anorexia, while the other three died without exhibiting clinical signs. Grossly, lungs of the kangaroo were dark red in color, while hyraxes, besides, showed hepatic multifocal white foci, and intestinal multifocal hemorrhages. Histologically, the kangaroo had frequent Toxoplasma gondii pseudocysts in brain, heart and skeletal muscles. All hyraxes had multifocal necrosis with cysts containing numerous bradyzoites in liver and spleen, along with necrotic gastroenteritis and intestinal hemorrhages. Immunohistochemically, cysts showed positive reaction to anti-T. gondii antibodies. These findings indicate possible outbreaks of toxoplasmosis in eastern grey kangaroos and cape hyraxes, zoo habitants; therefore, they could be susceptible intermediate hosts for T. gondii in terms of zoonosis. This is the first report of toxoplasmosis in eastern grey kangaroos and cape hyraxes in Japanese zoos.

  6. Monitoring of oil hydrocarbons pollution in the Sea of Japan, based on detection of marker genes in microbial communities

    Science.gov (United States)

    Kim, A. V.; Buzoleva, L. S.; Bogatyrenko, E. A.; Zemskaya, T. I.; Mamaeva, E. V.

    2018-01-01

    By means of molecular biology techniques, metabolic potential of microbial communities within the regions of inshore water areas in the Sea of Japan with various anthropogenic load was explored. Presence of functional genes, responsible for oil hydrocarbons destruction, for microbial communities within the regions of inshore water areas in the Sea of Japan was first researched. In total microbial DNA from water mass in the regions with chronic anthropogenic pollution, the genes, responsible for oxidation of broad range of n-alkanes and polycyclic aromatic hydrocarbons, were found. Detection of marker genes in the background water area (in the Vostok Bay) was ever indicating ecological deterioration within this territory. Thereby, it was demonstrated, that molecular genetic methods, aimed at marker gene detection in total bacterial DNA from environment objects, proved themselves to be more effective technique for identification of oil hydrocarbons water pollution, in comparison with trivial culturable methods.

  7. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily, Central Mediterranean Sea

    Science.gov (United States)

    Sciacca, Virginia; Caruso, Francesco; Beranzoli, Laura; Chierici, Francesco; De Domenico, Emilio; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Simeone, Francesco; Viola, Salvatore; Riccobene, Giorgio

    2015-01-01

    In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, “NEMO-SN1”, deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz–1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9–22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise. PMID:26581104

  8. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus Offshore Eastern Sicily, Central Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Virginia Sciacca

    Full Text Available In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea, throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, "NEMO-SN1", deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz-1 kHz, sampling rate: 2 kHz which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9-22.5 Hz was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise.

  9. 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

  10. Vertical distributions and speciation of dissolved rare earth elements in the anoxic brines of Bannock Basin, eastern Mediterranean Sea

    NARCIS (Netherlands)

    Schijf, Johan; Baar, Hein J.W. de; Millero, Frank J.; Byrne, R.H.

    1995-01-01

    Vertical distributions of dissolved rare earth elements (REEs) are presented for the anoxic, highly sulfidic brines of Bannock Basin in the eastern Mediterranean Sea. REE concentrations at the seawater-brine interface are the highest ever recorded in the water column of an anoxic basin and

  11. Short-term variability in halocarbons in relation to phytoplankton pigments in coastal waters of the central eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Roy, R.

    with pigment composition were monitored in the coastal waters of the central eastern Arabian Sea. Short-term variability for the period December 2005-March 2007 was studied for chlorinated hydrocarbons (CHCl sub(3), CCl sub(4)) and bromocarbons (CH sub(2)Br sub...

  12. Early- to late-Holocene contrast in productivity, OMZ intensity and calcite dissolution in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.; Godad, S.P.; Naidu, P.D.; Tiwari, M.; Paropkari, A.L.

    . In this perspective, we report here that the Eastern Arabian Sea experienced coeval increase in productivity and denitrification from ~7 to 0 kyr, which coincides with minimum dissolved oxygen levels in bottom waters. In addition, during the same period, an increased...

  13. On an upwelling front, propagation of upwelling and vertical velocity in the eastern Arabian sea during monsoon, 1987

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Unnikrishnan, A.S.

    A coastal upwelling front parallel to the coast and identifiable upto a depth of 75 m was observed between 12.5 and 16 degrees N along the eastern Arabian Sea in September, 1987 from closely spaced digital BT data. With a north-south slope...

  14. Diverse methane concentrations in anoxic brines and underlying sediments, eastern Mediterranean Sea

    Science.gov (United States)

    Karisiddaiah, S. M.

    2000-10-01

    Elevated methane (CH 4) concentrations (128-2692×10 3 nM) occur in the hypersaline anoxic brine pools of Bannock and Urania Basins, eastern Mediterranean Sea, compared to low concentrations (17-80×10 3 nM) in the sediments below the anoxic brines. The CH 4 enrichment in the brines might be due to the long residence time of the brine in the Basin. An attempt is made to determine the sources for the enriched dissolved CH 4 by considering the influence of hydrothermal activity, the occurrence of sapropel layers (biogenic) and dissolution of gas hydrates. Furthermore, it is suggested that the enriched CH 4 in Bannock and Urania Basins is diffused and mixed with the overlying waters by local upward transport mechanisms that selectively move CH 4 upward in these Basins.

  15. On the climatological mean circulation over the eastern Bering Sea shelf

    Science.gov (United States)

    Reed, R. K.; Stabeno, P. J.

    1996-08-01

    We derive climatological mean summer circulation over the eastern Bering Sea shelf. Geostrophic flow (from CTD data, 1975-1989) and drifter velocities (from satellite-tracked buoys, 1986-1994) were used. The following features are shown: (1) in depths >100 m, a northwestward flow of ˜4 cm s -1, which is largely baroclinic; (2) near the 50 m isobath, a flow of ˜2 cm s -1 , which is only partially baroclinic; and (3) a semi-permanent, convoluted flow of 1-2 cm s -1, between the 100 and 50 m isobaths, that was not recognized in earlier analyses. Data from current moorings indicate that there is no significant tidal enhancement of net flow on the shelf as earlier suggested. This new climatology also shows clearly a divergence of the inflow through Unimak Pass, and it suggests that the shelf salinity distribution is influenced by advection as well as diffusion.

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

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2015-10-01

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

  17. Isotopic characteristics of shells Mytilus galloprovincialis from eastern coastal area of Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Tjaša Kanduč

    2006-06-01

    Full Text Available Samples of Mytilus galloprovincialis were collected from entire Eastern Adriatic coast to determine δ18O and δ13C performed on calcite and aragonite shell layers. The aim of this work was to check whether shells of M. galloprovincialis are good environmental indicators (water temperature, salinity. Based on measured isotopic composition of oxygen in shell layers and assumed isotopic composition in water temperatures of calcite and aragonite of shell layers were calculated. The calculated temperatures for M. galloprovincialis shell growth of calcite and aragonite shell layer are in good agreement with measured temperatures of sea water. According to our results of δ18O and δ13C in shell layers we canseparate the locations of the investigated area into three groups: those with more influence of fresh water, those with less influence of fresh water and those of marine environments.

  18. Biodiversity of zoobenthic hard-substrate sublittoral communities in the Eastern Mediterranean (North Aegean Sea)

    Science.gov (United States)

    Antoniadou, Chryssanthi; Chintiroglou, Chariton

    2005-03-01

    The spatial dispersion of zoobenthos from sublittoral hard substrate communities in the northern part of the Aegean Sea has been studied during summer 1997 and 1998. Material was collected by SCUBA diving, by totally scraping off five replicate quadrates (400 cm 2 each) at three depth levels (15, 30, 40 m) from six sites located in Chalkidiki peninsula, plus one in Kavala Gulf. The examination of the 19,343 living specimens collected revealed the presence of 314 species. Though the multivariate analyses showed high similarity between stations, the structure of this sciaphilic algal community seems to have an increased spatial heterogeneity. Four distinct facies were recorded in accordance with the occurrence of different algal forms, the degree of hard substrate inclination and the water clarity. A short review on the biodiversity of sublittoral communities in the Mediterranean revealed the affinity between the western and the eastern basin and also among the photophilic and the sciaphilic algal communities.

  19. Correlations between sea surface temperature, circulation patterns and the distribution of hermatypic corals of Japan

    Science.gov (United States)

    Veron, J. E. N.; Minchin, Peter R.

    1992-07-01

    Techniques of multivariate exploratory data analysis and regression are used to examine correlations between patterns of distribution of the hermatypic corals of the Ryukyu Islands and mainland Japan, sea surface temperature (SST) and dispersal time. The species composition of all localities is highly correlated with geographic position, with species richness decreasing with latitude. There is an abrupt decrease in diversity between reefal (Ryukyu Islands) and non-reefal (mainland) localities. The compositional data are strongly unidimensional and this dimension is correlated with SST. There are eight high latitude endemic species as well as other species "locked-up" in northern localities as a result of the northward-flowing Kuroshio Current. On a broad scale, overall similarity in coral species composition can be predicted solely from absolute differences in SST and dispersal time makes no significant contribution. Except for short term or localized chilling, the minimum SST for coral reef development is 18°C. Of all Japanese species, 22.5% tolerate a minimum SST of 10.4°C, 27% tolerate 13.2°C and 48% tolerate 14.1°C. Thus, approximately half of all species tolerate temperatures 4°C below the 18°C minimum required for reef development.

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

    Science.gov (United States)

    Aydın-Önen, S

    2016-11-01

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

  1. Nutrient Limitation in Surface Waters of the Oligotrophic Eastern Mediterranean Sea: an Enrichment Microcosm Experiment

    KAUST Repository

    Tsiola, A.

    2015-12-01

    The growth rates of planktonic microbes in the pelagic zone of the Eastern Mediterranean Sea are nutrient limited, but the type of limitation is still uncertain. During this study, we investigated the occurrence of N and P limitation among different groups of the prokaryotic and eukaryotic (pico-, nano-, and micro-) plankton using a microcosm experiment during stratified water column conditions in the Cretan Sea (Eastern Mediterranean). Microcosms were enriched with N and P (either solely or simultaneously), and the PO4 turnover time, prokaryotic heterotrophic activity, primary production, and the abundance of the different microbial components were measured. Flow cytometric and molecular fingerprint analyses showed that different heterotrophic prokaryotic groups were limited by different nutrients; total heterotrophic prokaryotic growth was limited by P, but only when both N and P were added, changes in community structure and cell size were detected. Phytoplankton were N and P co-limited, with autotrophic pico-eukaryotes being the exception as they increased even when only P was added after a 2-day time lag. The populations of Synechococcus and Prochlorococcus were highly competitive with each other; Prochlorococcus abundance increased during the first 2 days of P addition but kept increasing only when both N and P were added, whereas Synechococcus exhibited higher pigment content and increased in abundance 3 days after simultaneous N and P additions. Dinoflagellates also showed opportunistic behavior at simultaneous N and P additions, in contrast to diatoms and coccolithophores, which diminished in all incubations. High DNA content viruses, selective grazing, and the exhaustion of N sources probably controlled the populations of diatoms and coccolithophores.

  2. Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda from Lebanon

    Directory of Open Access Journals (Sweden)

    F. CROCETTA

    2013-07-01

    Full Text Available A reviewed knowledge of the opisthobranch species from Lebanon (eastern Mediterranean Sea, based on literature records (scattered throughout various papers published over a period of more than 150 years and recently collected material (1999-2002 within the CEDRE framework and other samples, is presented, yielding a total number of 35 taxa recorded from the Lebanese shores identified to species level. Special emphasis has mainly been given to the alien species, for which scattered notes are also given. The known opisthobranch biota is composed of 22 native (~ 63%, 12 alien (~ 34% and one cryptogenic (~ 3% taxa. Eleven of these (Berthella aurantiaca, B. ocellata, Aplysia fasciata, Felimare picta, Felimida britoi, F. luteorosea, F. purpurea, Phyllidia flava, Dendrodoris grandiflora, D. limbata and Aeolidiella alderi constitute new records for the Lebanese fauna, whilst the examined material of a further seven species (Elysia grandifolia, Pleurobranchus forskalii, Aplysia dactylomela, Bursatella leachii, Syphonota geographica, Goniobranchus annulatus, Flabellina rubrolineata anecdotally cited from Lebanon on the basis of the samples here studied, is here first explained. One additional taxon belonging to the genus Haminoea has been identified to genus level only. Despite the searching effort poning the basis of the material analyzed here, data reported clearly suggest that strong investments are still needed for a better understanding of the eastern Mediterranean opisthobranch fauna.

  3. Mitochondrial Control Region Variability in Mytilus galloprovincialis Populations from the Central-Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Ioannis A. Giantsis

    2014-06-01

    Full Text Available The variable domain 1 (VD1 domain of the control region and a small segment of the rrnaL gene of the F mtDNA type were sequenced and analyzed in 174 specimens of Mytilus galloprovincialis. Samples were collected from eight locations in four Central-Eastern (CE Mediterranean countries (Italy, Croatia, Greece and Turkey. A new primer, specific for the F mtDNA type, was designed for the sequencing procedure. In total 40 different haplotypes were recorded, 24 of which were unique. Aside from the two populations situated in Thermaikos gulf (Northern Aegean, Greece, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and Eastern Mediterranean populations. Eight out of the 40 haplotypes were shared by at least three populations while two of them were found in all populations. ΦST and cluster analysis revealed lack of structuring among CE Mediterranean populations with the exception of those located at the Sea of Marmara and Croatian coast which were highly differentiated. Apart from the species’ inherit dispersal ability, anthropogenic activities, such as the repeated translocations of mussel spat, seem to have played an important role in shaping the current genetic population structure of CE M. galloprovincialis mussels.

  4. Indications of low macrobenthic activity in the deep sediments of the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Daniela Basso

    2004-12-01

    Full Text Available The fluxes and budget of organic matter from the oligotrophic surface waters of the eastern Mediterranean to the deep waters are poorly known, and little information is available on past and present macrobenthic activity on the sea floor. Evidence of macrobenthic activity can be direct, through recovery of living organisms or their autochthonous skeletal remains, or indirect, through bioturbation and trace fossils. The evidence of biological activity in deep eastern Mediterranean sediments has been evaluated and compared through 210Pb profiles from box-cores and study of dredge samples from sites on Medina Rise (1374 m water depth, the Messina Abyssal Plain (4135 m and several sites along the Mediterranean Ridge, SW and S of Crete (1783 to 3655 m. All these sites are remote from the continental shelves, so the biological benthic activity is expected to depend primarily on primary production from surface waters. The results show that present-day macrobenthos and trace fossils are generally scarce, especially at depths > 2500 m. This observation is supported by surface sediment 210Pb excess distributions that show a surface mixed layer (SML 2500 m. The historical layer of some box-cores and the Pleistocene hardgrounds collected in the Cleft area (Mediterranean Ridge do, however, record a macrobenthic activity that is apparently more intense than at present, which may be related to higher primary production of the Pleistocene glacial intervals. In contrast with most areas of the present-day deep eastern Mediterranean which depend on surface primary production based on photosynthesis, a relatively dense and diversified macrobenthic community based on chemosynthesis has been recognised at depths > 1100 m on the Napoli Dome mud volcano in the Olimpi area, and on the Kazan and other mud volcanoes in the Anaximander Mountains.

  5. Atmospheric variables, nutrients, pH, salinity, and temperature collected by bottle and from meteorological stations in the Sea of Japan and the Yellow Sea from 01 July 1952 to 31 December 1998 (NODC Accession 0000032)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atmospheric variables, nutrients, pH, salinity, and temperature data were collected using bottle casts in the Sea of Japan from 01 July 1952 to 31 December 1998....

  6. Lithospheric Response of the Anatolian Plateau in the Realm of the Black Sea and the Eastern Mediterranean

    Science.gov (United States)

    Ergun, Mustafa

    2016-04-01

    The Eastern Mediterranean and the Middle East make up the southern boundary of the Tethys Ocean for the last 200 Ma by the disintegration of the Pangaea and closure of the Tethys Ocean. It covers the structures: Hellenic and Cyprus arcs; Eastern Anatolian Fault Zone; Bitlis Suture Zone and Zagros Mountains. The northern boundary of the Tethys Ocean is made up the Black Sea and the Caspian Sea, and it extends up to Po valley towards the west (Pontides, Caucasus). Between these two zones the Alp-Himalayan orogenic belt is situated where the Balkan, Anatolia and the Iran plateaus are placed as the remnants of the lost Ocean of the Tethys. The active tectonics of the eastern Mediterranean is the consequences of the convergence between the Africa, Arabian plates in the south and the Eurasian plate in the north. These plates act as converging jaws of vise forming a crustal mosaic in between. The active crustal deformation pattern reveals two N-S trending maximum compression or crustal shortening syntaxes': (i) the eastern Black Sea and the Arabian plate, (ii) the western Black Sea and the Isparta Angle. The transition in young mountain belts, from ocean crust through the agglomeration of arc systems with long histories of oceanic closures, to a continental hinterland is well exemplified by the plate margin in the eastern Mediterranean. The boundary between the African plate and the Aegean/Anatolian microplate is in the process of transition from subduction to collision along the Cyprus Arc. Since the Black Sea has oceanic lithosphere, it is actually a separate plate. However it can be considered as a block, because the Black Sea is a trapped oceanic basin that cannot move freely within the Eurasian Plate. Lying towards the northern margin of orogenic belts related to the closure of the Tethys Ocean, it is generally considered to be a result of back-arc extension associated with the northward subduction of the Tethyan plate to the south. Interface oceanic lithosphere at

  7. Rapid Response of Eastern Mediterranean Deep Sea Microbial Communities to Oil

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiang; Techtmann, Stephen M.; Woo, Hannah L.; Ning, Daliang; Fortney, Julian L.; Hazen, Terry C.

    2017-07-18

    Deep marine oil spills like the Deepwater Horizon (DWH) in the Gulf of Mexico have the potential to drastically impact marine systems. Crude oil contamination in marine systems remains a concern, especially for countries around the Mediterranean Sea with off shore oil production. The goal of this study was to investigate the response of indigenous microbial communities to crude oil in the deep Eastern Mediterranean Sea (E. Med.) water column and to minimize potential bias associated with storage and shifts in microbial community structure from sample storage. 16S rRNA amplicon sequencing was combined with GeoChip metagenomic analysis to monitor the microbial community changes to the crude oil and dispersant in on-ship microcosms set up immediately after water collection. After 3 days of incubation at 14 °C, the microbial communities from two different water depths: 824 m and 1210 m became dominated by well-known oil degrading bacteria. The archaeal population and the overall microbial community diversity drastically decreased. Similarly, GeoChip metagenomic analysis revealed a tremendous enrichment of genes related to oil biodegradation, which was consistent with the results from the DWH oil spill. These results highlight a rapid microbial adaption to oil contamination in the deep E. Med., and indicate strong oil biodegradation potentia

  8. Observations of radiation bursts from winter thunderclouds and lighting over the Japan sea coast

    Science.gov (United States)

    Umemoto, D.; Tsuchiya, H.; Enoto, T.; Yamada, S.; Yuasa, T.; Kawaharada, M.; Kitaguchi, T.; Nakazawa, K.; Kokubun, M.; Iwata, K.; Kato, H.; Okano, M.; Tamagawa, T.; Makishima, K.

    2013-12-01

    Radiation bursts associated with lightning and thunderstorms are reported by an increasing number of experiments, either ground-based or space-borne. These bursts are thought to be produced via Bremsstrahlung by energetic electrons, which are accelerated in the electrical fields within thunderclouds. GROWTH (Gamma-Ray Observation of Winther THunderclouds) experiment has been operating over 7 seasons since 2006, in Kashiwazaki-Kariwa nuclear power plant located in Niigata prefecture, Japan, facing the Japan sea (Tsuchiya et al., Phys. Rev. Lett. 99, 165002, 2007). It aims to detect radiation from winter thunderclouds in this region, which are known to have very low cloud-base altitudes and to involve huge lightning energies. With GROWTH, we have so far detected 20 radiation bursts, which can be classified distinctly into 12 long-duration events (Tsuchiya et al., JGR 116, D09113, 2011) and 8 short-lived ones. The former ones have durations up to several minutes without correlation with lightning, and are likely to be associated with thunderclouds themselves. The latter ones are coincident with lightning discharges, and last for less than 1 second. In both types of events, gamma-ray energy spectra extend typically up 10 MeV. As described below, the present study covers both types of events. In a long burst which occurred on 2010 December 30, the gamma-ray intensity gradually increased and the spectrum continuously hardened over a few minutes, and then the emission abruptly ceased (Tsuchiya et al., Phys. Rev. Lett. 111, 015001, 2013). This sudden termination preceded (by 800 ms or less) a lightning flash that occurred 5 km away form the GROWTH site. We are also analyzing two short bursts detected on 2012 January 13, and another on 2012 December 9, all of which lasted no longer than 300 ms. In the spectrum of one of them, we found evidence of excess emission around 511 keV. The line emission increased in coincidence with the continuum radiation, but lasted for more than

  9. Development of a three-dimensional variational data assimilation system for the Seto Island Sea, Japan

    Science.gov (United States)

    Kurosawa, K.; Uchiyama, Y.

    2016-12-01

    By optimally combined ocean models with observation data, numerical oceanic reanalysis and forecast systems allow us to predict the ocean more precisely. In general, data assimilation is exploited to prepare the initial condition for the forecast. This technique has widely been employed in atmospheric prediction, whereas oceanic prediction lags behind weather forecast. Accurate oceanic prediction systems have been demanded for operational purposes such as for fisheries, vessel navigation, marine construction, offshore platform management, marine monitoring, etc. In particular, in crowded harbors and estuaries including the Seto Inland Sea (SIS), Japan, data assimilation has seldom been adapted because data from satellites and Argo floats essential to successful oceanic predictions is desperately limited. In addition, although static data assimilation, typically three-dimensional variational data assimilation (3DVAR), is computationally cheap and statistically optimal, but is not physically balanced. For instance, 3DVAR is known to modify velocity and density fields merely mathematically, yet it does not adequately consider quasi-geostrophic balance, which is generally true in most cases. In the present study, we develop a 3DVAR system for Regional Oceanic Modeling Systems (ROMS) and apply to the high-resolution SIS model in a double nested configuration (Kosako et al., 2015). The SIS is the largest estuary in Japan with a number of autonomous in-situ monitoring of vertical profiles of temperature and salinity, tens of tidal gages, along with continuous surface current measurement using HF radars. We first present a theoretical framework of the 3DVAR algorithm by considering geostrophic and thermal-wind balance to find plausible relationships among physical variables to avoid undesirable modifications. Subsequently, the developed 3DVAR is coupled with the SIS ROMS model to compare the model outcomes against some observation data. The 3DVAR ROMS model for the SIS

  10. Offshore evidence of postglacial relative sea-level change from eastern Ireland.

    Science.gov (United States)

    Callard, S. Louise; Long, Antony J.; Plets, Ruth M.; Cooper, J. Andrew; Belknap, Daniel F.; Edwards, Robin J.; Jackson, Derek W. T.; Kelley, Joseph T.; Long, David; Milne, Glenn A.; Monteys, Xavier; Quinn, Rory

    2014-05-01

    Field evidence and Glacial Isostatic Adjustment (GIA) models help constrain the extent of the British Irish Ice Sheet (BIIS) during and since the Last Glacial Maximum (LGM). Because of differential ice loading histories, relative sea-level (RSL) changes at sites from around the Irish Sea basin are complex. Existing GIA models are constrained using sea-level observations and some poorly dated and unevenly distributed ice margin data, but there is a paucity of RSL observations below -10 m OD that spans the Late Glacial, a period of abrupt RSL change that includes at least one meltwater pulse. Addressing this interval of time requires the collection of new field data from offshore regions around Ireland, taking advantage of recent advances in remote sensing techniques. This paper presents results from offshore eastern Ireland, one of seven areas targeted as part of a larger NERC funded project 'Late Glacial sea-level minima in the Irish Sea'. Previous research in this region has focused on dating raised marine sediments from exposed onshore coastal sections that represent periods of RSL highstands during the early deglaciation. However, the significance of these data for RSL reconstruction and hence their constraints on GIA models is debated. Here we use a combination of marine geophysics (multibeam bathymetry and backscatter, pinger sub-bottom profiler) vibro-coring and laboratory analyses to reconstruct Late Glacial RSL change from this region. The area's bathymetry demonstrate a strong glacial imprint on the northern side of the study area, with a large arcuate fan extending from Dundalk Bay to -18m, perhaps formed during a period of ice readvance, most likely during the Killard Point Stadial (c. 16.5 k cal a BP). Pinger seismic data allow the identification of six seismo-stratigraphic units, of which the most notable is a chaotic unit sitting on a prominent reflector that can be traced between -22 m to -50 m. The unit is interpreted as a gravel lag overlying

  11. Numerical modelling of the buoyant marine microplastics in the South-Eastern Baltic Sea

    Science.gov (United States)

    Bagaev, Andrei; Mizyuk, Artem; Chubarenko, Irina; Khatmullilna, Liliya

    2017-04-01

    Microplastics is a burning issue in the marine pollution science. Its sources, ways of propagation and final destiny pose a lot of questions to the modern oceanographers. Hence, a numerical model is an optimal tool for reconstruction of microplastics pathways and fate. Within the MARBLE project (lamp.ocean.ru), a model of Lagrangian particles transport was developed. It was tested coupled with oceanographic transport fields from the operational oceanography product of Copernicus Marine Monitoring Environment Service. Our model deals with two major types of microplastics such as microfibres and buoyant spheroidal particles. We are currently working to increase the grid resolution by means of the NEMO regional configuration for the south-eastern Baltic Sea. Several expeditions were organised to the three regions of the Baltic Sea (the Gotland, the Bornholm, and the Gdansk basins). Water samples from the surface and different water layers were collected, processed, and analysed by our team. A set of laboratory experiments was specifically designed to establish the settling velocity of particles of various shapes and densities. The analysis in question provided us with the understanding necessary for the model to reproduce the large-scale dynamics of microfibres. In the simulation, particles were spreading from the shore to the deep sea, slowly sinking to the bottom, while decreasing in quantity due to conditional sedimentation. Our model is expected to map out the microplastics life cycle and to account for its distribution patterns under the impact of wind and currents. For this purpose, we have already included the parameterization for the wind drag force applied to a particle. Initial results of numerical experiments seem to indicate the importance of proper implicit parameterization of the particle dynamics at the vertical solid boundary. Our suggested solutions to that problem will be presented at the EGU-2017. The MARBLE project is supported by Russian Science

  12. An inverse modeling study of circulation in the Eastern Bering Sea during 2007-2010

    Science.gov (United States)

    Panteleev, Gleb; Yaremchuk, Max; Francis, Oceana; Stabeno, Phyllis J.; Weingartner, T.; Zhang, J.

    2016-06-01

    A two-way nested 4d-variational data assimilation system is implemented in the Eastern Bering Sea (EBS) to investigate changes in circulation and thermodynamic state for a 3.8 year period. Assimilated observations include data from 19 moorings deployed on the shelf and in the Bering Strait, 1705 hydrographic stations occupied during eight surveys, and remotely sensed sea surface temperature and sea surface height (SSH) data. Validation of the presented 4dVar reanalysis against the output of two sequential data-assimilative systems (the Bering Ecosystem Study ice-ocean Modeling and Assimilation System (BESTMAS) and the Arctic Cap Nowcast-Forecast System (ACNFS)) has shown that the product is more consistent with the observed transports in the Bering Strait and in the EBS interior both in terms of their magnitude and time variability. Analysis of the data-optimized solution quantifies a sequence of wind-forced events that resulted in the anomalous heat and freshwater transports through the Bering Strait, including a 28 day long flow reversal that occurred in November 2009 and carried Siberian Coastal Current water down to the Gulf of Anadyr. Lagrangian study of the Arctic-bound Pacific waters indicates the extreme importance of the cross-shelf exchange along the path of the Bering Slope Current and quantifies the spectrum of residence times for the waters entering EBS through Unimak Pass and through Aleutian passages. Residence times in the EBS cold pool are diagnosed to be 2-3 times longer than those in the surrounding waters.

  13. Evidence of increased toxic Alexandrium tamarense dinoflagellate blooms in the eastern Bering Sea in the summers of 2004 and 2005.

    Directory of Open Access Journals (Sweden)

    Masafumi Natsuike

    Full Text Available The eastern Bering Sea has a vast continental shelf, which contains various endangered marine mammals and large fishery resources. Recently, high numbers of toxic A. tamarense resting cysts were found in the bottom sediment surface of the eastern Bering Sea shelf, suggesting that the blooms have recently occurred. However, little is known about the presence of A. tamarense vegetative cells in the eastern Bering Sea. This study's goals were to detect the occurrence of A. tamarense vegetative cells on the eastern Bering Sea shelf and to find a relationship between environmental factors and their presence. Inter-annual field surveys were conducted to detect A. tamarense cells and environmental factors, such as nutrients, salinity, chlorophyll a, and water temperature, along a transect line on the eastern Bering Sea shelf during the summers of 2004, 2005, 2006, 2009, 2012, and 2013. A. tamarense vegetative cells were detected during every sampling year, and their quantities varied greatly from year to year. The maximum cell densities of A. tamarense observed during the summers of 2004 and 2005 were much higher than the Paralytic shellfish poisoning warning levels, which are greater than 100-1,000 cells L-1, in other subarctic areas. Lower quantities of the species occurred during the summers of 2009, 2012, and 2013. A significant positive correlation between A. tamarense quantity and water temperature and significant negative correlations between A. tamarense quantity and nutrient concentrations (of phosphate, silicate, and nitrite and nitrate were detected in every sampling period. The surface- and bottom-water temperatures varied significantly from year to year, suggesting that water temperatures, which have been known to affect the cell growth and cyst germination of A. tamarense, might have affected the cells' quantities in the eastern Bering Sea each summer. Thus, an increase in the Bering Sea shelf's water temperature during the summer will

  14. The impact of surface currents and sea level on the wave field evolution during St. Jude storm in the eastern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Marili Viitak

    2016-07-01

    Full Text Available A third generation numerical wave model SWAN (Simulating WAves Nearshore was applied to study the spatio-temporal effect of surface currents and sea level height on significant wave height; and to describe the mechanisms responsible for wave–current interaction in the eastern Baltic Sea. Simulation results were validated by comparison with in situ wave measurements in deep and shallow water, carried out using the directional wave buoy and RDCP respectively, and with TerraSAR-X imagery. A hindcast period from 23 to 31 October 2013 included both a period of calm to moderate weather conditions and a severe North-European windstorm called St. Jude. The prevailing wind directions were southerly to westerly. Four simulations with SWAN were made: a control run with dynamical forcing by wind only; and simulations with additional inputs of surface currents and sea level, both separately and combined. A clear effect of surface currents and sea level on the wave field evolution was found. It manifested itself as an increase or decrease of significant wave height of up to 20%. The strength of the interaction was influenced by the propagation directions of waves and surface currents and the severity of weather conditions. An increase in the wave height was mostly seen in shallower waters and in areas where waves and surface currents were propagating in opposite directions. In deeper parts of the eastern Baltic Sea and in case of waves and surface currents propagating in the same direction a decrease occurred.

  15. Instability of bottom-water redox conditions during accumulation of Quaternary sediment in the Japan Sea

    Science.gov (United States)

    Piper, D.Z.; Isaacs, C.M.

    1996-01-01

    The concentrations of Cd, Cr, Cu, Mo, Ni, Sb, U, V, and Zn were measured in early Quaternary sediment (1.32 to 1.08 Ma) from the Oki Ridge in the Japan Sea. The elements were partitioned between a detrital fraction, composed of terrigenous and volcaniclastic aluminosilicate debris, and a marine fraction, composed of biogenic and hydrogenous debris derived from seawater. The most important factors controlling minor-element accumulation rates in the marine fraction were (1) primary productivity in the photic zone, which largely controlled the flux of particulate organic-matter-bound minor elements settling through the water column and onto the seafloor, and (2) bottom-water redox, which determined the suite of elements that accumulated directly from seawater. This marine fraction of minor elements on Oki Ridge recorded six periods of high minor-element abundance. Assuming a constant bulk sediment accumulation rate, each period lasted roughly 5,000 to 10,000 years with a 41,000-year cycle. Accumulation rates of individual elements such as Cd, Mo, and U suggest sulfate-reducing conditions were established in the bottom water during the 10,000-year periods; accumulation rates of Cr and V during the intervening periods are indicative of less reducing, denitrifying conditions. Interelement ratios, for example, Cu:Mo, V:Cr, and Sb:Mo, further reflect bottom-water instability, such that bottom-water redox actually varied from sulfate reducing to denitrifying during the periods of highest minor-element accumulation rates; it varied from denitrifying to oxidizing during the intervening periods. Sediment lithology supports these interpretations of the minor-element distributions; the sediment is finely laminated for several of the periods represented by Cd, Mo, and U maxima and weakly laminated to bioturbated for the intervening periods. The geochemistry of this sediment demonstrates the unambiguous signal of Mo, principally, but of several other minor elements as well in

  16. Deterioration of eelgrass, Zostera marina L., meadows by water pollution in Seto Inland Sea, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Hitoshi; Tokuoka, Makoto; Nishijima, Wataru; Terawaki, Toshinobu; Okada, Mitsumasa

    2002-11-01

    Survival of transplanted Zostera marina L. (eelgrass) and environmental conditions (water quality, bottom sediments, sedimentation on leaves and flow regime) were studied concurrently in the center, edge, and at the outside of a eelgrass meadow located in a eutrophic coastal zone in northern Hiroshima Bay, Seto Inland Sea, Japan. Eelgrass transplants at the outside of the meadow declined significantly, whereas those at the center were consistently well established. Silt content in the bottom sediments at the outside was higher than that at the center. The sediment was oxic from the surface to 2 cm deep at the center, whereas those at the edge and the outside were reductive almost from the surface. The sediment characteristics typical in eutrophic water seemed to be a factor responsible for the deterioration of eelgrass meadows. Although suspended solid concentrations in the water columns were almost the same, the amount of sediments deposited on leaves of eelgrass at the outside was higher than that at the center of the meadow. The amount of the deposition at the outside seems to be enough to inhibit photosynthesis; i.e. photosynthetic photon flux density (PPFD) available for eelgrass was only 36% of that without any deposition. The deposition in the center, however, was small enough to allow 84% of the original PPFD. Flow rates, determined at 30 cm above the bottom, a half height of average eelgrass, suggested that the rate at the outside was not enough to remove deposited sediments from the surface of eelgrass leaves. Thus, the large amount of sediment deposition caused by water pollution and/or eutrophication seemed to be another factor to inhibit the survival of eelgrass at the outside edge of the meadow.

  17. Deterioration of eelgrass, Zostera marina L., meadows by water pollution in Seto Inland Sea, Japan

    International Nuclear Information System (INIS)

    Tamaki, Hitoshi; Tokuoka, Makoto; Nishijima, Wataru; Terawaki, Toshinobu; Okada, Mitsumasa

    2002-01-01

    Survival of transplanted Zostera marina L. (eelgrass) and environmental conditions (water quality, bottom sediments, sedimentation on leaves and flow regime) were studied concurrently in the center, edge, and at the outside of a eelgrass meadow located in a eutrophic coastal zone in northern Hiroshima Bay, Seto Inland Sea, Japan. Eelgrass transplants at the outside of the meadow declined significantly, whereas those at the center were consistently well established. Silt content in the bottom sediments at the outside was higher than that at the center. The sediment was oxic from the surface to 2 cm deep at the center, whereas those at the edge and the outside were reductive almost from the surface. The sediment characteristics typical in eutrophic water seemed to be a factor responsible for the deterioration of eelgrass meadows. Although suspended solid concentrations in the water columns were almost the same, the amount of sediments deposited on leaves of eelgrass at the outside was higher than that at the center of the meadow. The amount of the deposition at the outside seems to be enough to inhibit photosynthesis; i.e. photosynthetic photon flux density (PPFD) available for eelgrass was only 36% of that without any deposition. The deposition in the center, however, was small enough to allow 84% of the original PPFD. Flow rates, determined at 30 cm above the bottom, a half height of average eelgrass, suggested that the rate at the outside was not enough to remove deposited sediments from the surface of eelgrass leaves. Thus, the large amount of sediment deposition caused by water pollution and/or eutrophication seemed to be another factor to inhibit the survival of eelgrass at the outside edge of the meadow

  18. Contrasting records of sea-level change in the eastern and western North Atlantic during the last 300 years

    Science.gov (United States)

    Long, A. J.; Barlow, N. L. M.; Gehrels, W. R.; Saher, M. H.; Woodworth, P. L.; Scaife, R. G.; Brain, M. J.; Cahill, N.

    2014-02-01

    We present a new 300-year sea-level reconstruction from a salt marsh on the Isle of Wight (central English Channel, UK) that we compare to other salt-marsh and long tide-gauge records to examine spatial and temporal variability in sea-level change in the North Atlantic. Our new reconstruction identifies an overall rise in relative sea level (RSL) of c. 0.30 m since the start of the eighteenth century at a rate of 0.9±0.3 mm yr. Error-in-variables changepoint analysis indicates that there is no statistically significant deviation from a constant rate within the dataset. The reconstruction is broadly comparable to other tide-gauge and salt-marsh records from the European Atlantic, demonstrating coherence in sea level in this region over the last 150-300 years. In contrast, we identify significant differences in the rate and timing of RSL with records from the east coast of North America. The absence of a strong late 19th/early 20th century RSL acceleration contrasts with that recorded in salt marsh sediments along the eastern USA coastline, in particular in a well-dated and precise sea-level reconstruction from North Carolina. This suggests that this part of the North Carolina sea level record represents a regionally specific sea level acceleration. This is significant because the North Carolina record has been used as if it were globally representative within semi-empirical parameterisations of past and future sea-level change. We conclude that regional-scale differences of sea-level change highlight the value of using several, regionally representative RSL records when calibrating and testing semi-empirical models of sea level against palaeo-records. This is because by using records that potentially over-estimate sea-level rise in the past such models risk over-estimating sea-level rise in the future.

  19. Resource assessment of methane hydrate in the eastern Nankai Trough, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, T.; Saeki, T.; Kobayashi, T.; Inamori, T.; Hayashi, M.; Takano, O.; Takayama, T.; Kawasaki, T.; Nagakubo, S.; Nakamizu, M.; Yokoi, K. [Japan Oil, Gas and Metals National Corp., Mihama-ku, Chiba (Japan). Technology and Research Center

    2008-07-01

    This study investigated the methane hydrate (MH) in the Nankai Trough offshore Japan as a potential natural gas resource. The resource assessment of MH was determined from the Ministry of Economy, Trade and Industry (METI) exploratory test wells Tokai-oki to Kumano-nada. Logging-while-drilling (LWD) campaigns were launched at 16 sites, coring at 4 sites and wirelogging at 2 sites. This study used high resolution 2D/3D seismic data and introduced a new concept for the MH concentrated zone and applied it to resource assessment. MH bearing layers in the survey area were classified into 2 categories, notably MH concentrated zones and MH bearing layers other than relatively thin, low saturated MH layers. The total amount of methane gas in place was estimated to be 40 tcf as Pmean value (10 tcf as P90, 82 tcf as P10). More than 10 prospective MH concentrated zones were extracted. They were characterized by high resistivity well logs, strong seismic reflectors, high p-wave interval velocity and turbidite deposits delineated by sedimentary facies analysis. The total gas in place for MH concentrated zones was estimated to be 20 tcf (half of the total amount) as Pmean value. Sensitivity analysis revealed that the net-to-gross ratio and methane pore saturation have higher sensitivity than other parameters. As such, they are important for further detail analysis. 22 refs., 3 tabs., 9 figs.

  20. Teleconnection between sea ice in the Barents Sea in June and the Silk Road, Pacific-Japan and East Asian rainfall patterns in August

    Science.gov (United States)

    He, Shengping; Gao, Yongqi; Furevik, Tore; Wang, Huijun; Li, Fei

    2018-01-01

    In contrast to previous studies that have tended to focus on the influence of the total Arctic sea-ice cover on the East Asian summer tripole rainfall pattern, the present study identifies the Barents Sea as the key region where the June sea-ice variability exerts the most significant impacts on the East Asian August tripole rainfall pattern, and explores the teleconnection mechanisms involved. The results reveal that a reduction in June sea ice excites anomalous upward air motion due to strong near-surface thermal forcing, which further triggers a meridional overturning wave-like pattern extending to midlatitudes. Anomalous downward motion therefore forms over the Caspian Sea, which in turn induces zonally oriented overturning circulation along the subtropical jet stream, exhibiting the east-west Rossby wave train known as the Silk Road pattern. It is suggested that the Bonin high, a subtropical anticyclone predominant near South Korea, shows a significant anomaly due to the eastward extension of the Silk Road pattern to East Asia. As a possible descending branch of the Hadley cell, the Bonin high anomaly ultimately triggers a meridional overturning, establishing the Pacific-Japan pattern. This in turn induces an anomalous anticyclone and cyclone pair over East Asia, and a tripole vertical convection anomaly meridionally oriented over East Asia. Consequently, a tripole rainfall anomaly pattern is observed over East Asia. Results from numerical experiments using version 5 of the Community Atmosphere Model support the interpretation of this chain of events.

  1. Variability and connectivity of plaice populations from the Eastern North Sea to the Baltic Sea, part II. Biological evidence of population mixing

    Science.gov (United States)

    Ulrich, Clara; Hemmer-Hansen, Jakob; Boje, Jesper; Christensen, Asbjørn; Hüssy, Karin; Sun, Hailu; Clausen, Lotte Worsøe

    2017-02-01

    A multi-disciplinary study was conducted to clarify stock identity and connectivity patterns in the populations of European plaice (Pleuronectes platessa) in the Skagerrak-Kattegat transition area between the Eastern North Sea and the Baltic Sea. Five independent biological studies were carried out in parallel. Genetic markers suggested the existence of different genetic populations in the transition area. Growth backcalculation with otoliths resulted in significant although limited differences in growth rates between North Sea and Skagerrak, indicating weak differentiation or important mixing. Hydrogeographical drift modelling suggested that some North Sea juveniles could settle along the coast line of the Skagerrak and the Kattegat. Tagging data suggested that both juveniles and adult fish from the North Sea perform feeding migrations into Skagerrak in summer/autumn. Finally, survey data suggested that Skagerrak also belongs to the area distribution of North Sea plaice. The outcomes of the individual studies were then combined into an overall synthesis. The existence of some resident components was evidenced, but it was also demonstrated that North Sea plaice migrate for feeding into Skagerrak and might constitute a large share of the catches in this area. The mixing of different populations within a management area has implications for stock assessment and management. Choice must be made to either lump or split the populations, and the feasibility and constraints of both options are discussed. The outcomes of this work have directly influenced the management decisions in 2015.

  2. Tectonostratigraphy of the Southern Part of Papua and Arafura Sea, Eastern Indonesia

    Directory of Open Access Journals (Sweden)

    Bhakti H. Harahap

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v7i3.145Sedimentary history and stratigraphy of the Papua and Arafura Sea areas, eastern Indonesia, are gained from surface geological mapping combined with published data from oil companies. Development of some sedimentary units demonstrates that the tectonism have influenced sedimentation of such units comprising a succession of Phanerozoic rocks developing in a stable continental margin. The succession underlain by Cambrian-Silurian-Devonian metamorphic rocks consists of Tuaba, Kariem, Awitagoh, and Kemum Formation, and Modio Dolomite (Pre-Rift Phase. These rocks having been intruded by Late Permian-Middle Triassic granitoids and Carboniferous granite, are unconformably overlain by Late Carboniferous to Cretaceous siliciclastic-rich units comprising Aifam Group and Tipuma Formation (syn-Rift Phase and Kembelangan Group (Mesozoic Passive Margin Post-Rift. The Aifam Group is separated by a regionally continuous boundary on its top contact from the Triassic-Early Jurassic Tipuma Formation, which filled the block-faulted rift valley subbasins of continentally deposited red beds in the breakup stage. Regionally, developed erosion surfaces of the breakup unconformity have separated these red beds from generally transgressive post-breakup deposits of the Jurassic to Cretaceous marine sediments of the Kembelangan Group. Beach to shallow marine-glauconitic sandstone and shale of the group pass upward into shelf mudstone. Relative sea level fall related to the tectonic stability of the area led to the development of Eocene to Late Miocene platform carbonates of the New Guinea Limestone Supergroup which occurred in the entire island of Papua and the southern of Arafura that overlie these non-carbonate units (Tertiary passive margin. It is separated from the siliciclastic-rich packages by the Tertiary - Pre-Tertiary boundary. The sea level fluctuation within the group was also recorded during the formation of thin, discontinuous

  3. Evidence for eddy formation in the eastern Arabian Sea during the northeast monsoon

    Science.gov (United States)

    Bruce, John G.; Johnson, Donald R.; Kindle, John C.

    1994-01-01

    The seasonal formation of a large (500-800 km diameter) anticyclonic eddy in the upper 300-400 m of the eastern Arabian Sea during the northest monsoon period (December-April) is indicated fom hydrographic and satellite altimetry sea level observations, as well as from numerical model experiments. The center of the eddy circulation is approximately 10 deg N, 70 deg E, just to the west of the north-south Laccadive Island chain. In this paper the eddy is called the Laccadive High (LH). In some ways it is like a mirrorlike counterpart to the Great Whirl that develops during the southwest monsoon of the Somali coast (western Arabian Sea). The LH occurs at the same latitude but on the opposite side of the basin during the reversed monsoon. It is different from the Great Whirl, however, in its formation process, its intensity, and its decay. The hydrographic data obtained from surveys all during a single season give sufficiently close station spacing to allow reasonable contouring of the geopotential surfaces and of the properties within and around the LH region with minimum time aliasing. The Geostat altimeter record extends over 4 years, during which the seasonal variability of the LH indicates a dynamic relief of approximately 15-20 cm, which is in good agreement with the hydrographics observations. The altimetry time series also suggests a westward translation of the LH by January with a subsequent dissipation in midbasin. The model used is a wind-forced three-layer primitive equation model which depicts a LH agreement with the timing, position, and amplitude of both the hydrographic and altimetric measurements. The numerical simulation includes a passive tracer located in the Western Bay of Bengal; the western advection of the tracer around the south coasts of Sri Lanka and India in December and January is consistent with the appearance of low-salinity water observed to extend into the Arabian Sea during this period. The modeling studies suggest that both local and

  4. Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Y.W. [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

    1997-02-01

    Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO{sub 2} in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO{sub 2} released from human activities after the industrial era. (author)

  5. Tracers confirm downward mixing of Tyrrhenian Sea upper waters associated with the Eastern Mediterranean Transient

    Directory of Open Access Journals (Sweden)

    W. Roether

    2011-01-01

    Full Text Available Observations of tritium and 3He in the Tyrrhenian Sea, 1987–2009, confirm the enhanced vertical mixing of intermediate waters into the deep waters that has been noted and associated with the Eastern Mediterranean Transient in previous studies. Our evidence for the mixing rests on increasing tracer concentrations in the Tyrrhenian deep waters, accompanied by decreases in the upper waters, which are supplied from the Eastern Mediterranean. The downward transfer is particularly evident between 1987 and 1997. Later on, information partly rests on increasing tritium-3He ages; here we correct the observed 3He for contributions released from the ocean floor. The Tyrrhenian tracer distributions are fully compatible with data upstream of the Sicily Strait and in the Western Mediterranean. The tracer data show that mixing reached to the bottom and confirm a cyclonic nature of the deep water circulation in the Tyrrhenian. They furthermore indicate that horizontal homogenization of the deep waters occurs on a time scale of roughly 5 years. Various features point to a reduced impact of Western Mediterranean Deep Water (WMDW in the Tyrrhenian during the enhanced-mixing period. This is an important finding because it implies less upward mixing of WMDW, which has been named a major process to enable the WMDW to leave the Mediterranean via the Gibraltar Strait. On the other hand, the TDW outflow for several years represented a major influx of enhanced salinity and density waters into the deep-water range of the Western Mediterranean.

  6. Evidence of methane venting and geochemistry of brines on mud volcanoes of the eastern Mediterranean Sea

    Science.gov (United States)

    Charlou, J. L.; Donval, J. P.; Zitter, T.; Roy, N.; Jean-Baptiste, P.; Foucher, J. P.; Woodside, J.; Medinaut Scientific Party

    2003-08-01

    As a part of the Dutch-French MEDINAUT diving expedition in 1998, cold seeps and mud volcanoes were studied and sampled in two distinctive tectonic settings in the eastern Mediterranean Sea. The first setting was the Olimpi Mud Volcano field (OMV area), including Napoli, Milano, Maidstone and Moscow mud volcanoes, south of Crete on the Mediterranean ridge. The second setting was the Anaximander Mountains (AM area), southwestern Turkey, where Amsterdam, Kazan and Kula mud volcanoes were explored. Large methane concentrations (45-892 nmol/kg) were measured in the water column not only above mud volcanoes but also in seeps and vents along related fault systems, indicating intense degassing related to fluid circulation in sediments. The tracer results show that there is considerable variability in terms of gas seepage and matter flux between these mud volcanoes. Brine accumulations found as shallow pools on Napoli or associated with deep faults (Nadir Lake) outside mud volcanoes exhibit variable chlorinity, mineral and gas composition. The brines are significantly enriched in δ18O relative to ambient seawater and are consistent with evaporated seawater. In the Nadir Brine Lake, the level of methane is as high as 5.93 mmol/kg, lower than the methane saturation level of 120 mmol/kg theoretically found at the salinity (120), pressure (200 bar), and temperature (13.6°C) conditions of Nadir lake. In contrast, the shallow brine pools on Napoli mud volcano (also OMV area) have methane levels of only 4.45 μmol/kg. In all brines, helium data show a clear radiogenic isotopic ratio ( R=0.06× Ra), in excellent agreement with recently published data for the Urania basin. Methane to ethane ratios (>1000) and δ13C(CH 4) values (-65.6‰PDB) indicate that the CH 4 is microbially produced. Unlike mid-ocean ridges, where abiogenic methane and helium have a common origin in the brines, the large variation in the CH 4/He ratio indicates that CH 4 and helium sources are unrelated, a

  7. Geological and geomechanical properties of the carbonate rocks at the eastern Black Sea Region (NE Turkey)

    Science.gov (United States)

    Ersoy, Hakan; Yalçinalp, Bülent; Arslan, Mehmet; Babacan, Ali Erden; Çetiner, Gözde

    2016-11-01

    Turkey located in the Alpine-Himalayan Mountain Belt has 35% of the natural stone reserves of the world and has good quality marble, limestone, travertine and onyx reserves especially in the western regions of the country. The eastern Black Sea Region with a 1.4 million meters cubes reserve has a little role on the natural stone production in the country. For this reason, this paper deals with investigation on the potential of carbonate stone in the region and determination of the geological and geo-mechanical properties of these rocks in order to provide economic contribution to the national economy. While the study sites are selected among the all carbonate rock sites, the importance as well as the representative of the sites were carefully considered for the region. After representative samples were analyzed for major oxide and trace element compositions to find out petrochemical variations, the experimental program conducted on rock samples for determination of both physical and strength properties of the carbonate rocks. The results of the tests showed that there are significant variations in the geo-mechanical properties of the studied rock groups. The density values vary from 2.48 to 2.70 gr/cm3, water absorption by weight values range from 0.07 to 1.15% and the apparent porosity of the carbonate rocks are between 0.19 and 3.29%. However, the values of the UCS shows variation from 36 to 80 MPa. Tensile and bending strength values range from 3.2 to 7.5 MPa and 6.0-9.2 MPa respectively. Although the onyx samples have the lowest values of apparent porosity and water absorption by weight, these samples do not have the highest values of UCS values owing to occurrence of the micro-cracks. The UCS values of the rock samples were also found after cycling tests However, the limestone samples have less than 5% deterioration after freezing-thawing and wetting-drying tests, but travertine and onyx samples have more than 15% deterioration. Exception of the apparent

  8. The surface circulation in the eastern basin of the Mediterranean Sea

    Science.gov (United States)

    Hamad, N.; Millot, C.; Taupier-Letage, I.

    2003-04-01

    The POEM-schema of the Atlantic Water (AW, http://ciesm.org/events/RT5-WaterMassAcronyms.pdf) circulation in the eastern basin of the Mediterranean Sea widely referred to nowadays (Robinson et al., 1991, completed by Robinson and Golnaraghi, 1993, and by Malanotte-Rizzoli et al., 1997) represents, in particular, a jet meandering offshore across the whole basin. No information is given on the southern part of the basin and no mention is made of a possible overall alongslope anticlockwise flow there, as suggested by a contemporaneous analysis of infrared satellite images (Le Vourch et al., 1992; Millot, 1992). A roughly similar controversy was elucidated in the western basin where such imagery was proven reliable. This has motivated the detailed analysis of daily and weekly composite images (about 1000) during the period 1996-2000, and of monthly composites available since 1985. Our analysis shows that AW circulates alongslope and anticlockwise around the whole basin, as indicated by Nielsen (1912) who considered the Coriolis effect as dominant. This circulation, which is permanent from Tunisia to Turkey, exists more or less temporarily in the Aegean, in the Ionian around Greece and in the Adriatic, due to the Etesians. However, a branch having spread for years (up to early 1998) from the channel of Sicily towards the northern Ionian before vanishing represents marked interannual (not seasonal) variability. Being unstable during most of its circuit, the AW flow generates mesoscale eddies which had not been correctly described before and which represent a relatively large amount of AW. Other eddies are known to be generated by orographic effects on the wind field, especially the Etesians. Both kinds of eddies play a fundamental role in spreading AW from alongslope towards the open basin. Although these eddies have characteristics almost specific to each subbasin and/or generation mechanism, the largest ones are anticyclonic, both kinds reach diameters of a few 100s km

  9. Benthic response to particulate fluxes in different trophic environments: a comparison between the Gulf of Lions Catalan Sea (western-Mediterranean) and the Cretan Sea (eastern-Mediterranean)

    Science.gov (United States)

    Danovaro, R.; Dinet, A.; Duineveld, G.; Tselepides, A.

    1999-08-01

    Quantitative information on particle fluxes, sedimentary OM composition, microbial and meiofaunal parameters is summarised from various stations in the Gulf of Lions and Catalan Sea (North-Western Mediterranean) and in the Cretan Sea (Eastern Mediterranean), investigated between 1993 and 1996. Benthic responses in relation to the different trophic conditions in the two areas were compared in terms of: (1) temporal and spatial variability of the mass fluxes; (2) pelagic-benthic coupling in organic matter composition (such as proteins, lipids, soluble carbohydrates and CPE); (3) microbial response to changes in organic matter composition and POC fluxes; (4) meiofaunal response to changes in organic matter composition and particle fluxes; (5) relative significance of bacteria and meiofauna. The two areas were also compared to identify ratios between productivity, vertical fluxes and benthic standing stocks. Mass fluxes at equal depths were up to two orders of magnitude higher in the Western than in the Eastern Mediterranean. Clear seasonal changes were reported in both areas, although mass fluxes and variability were consistently higher in the North-Western Mediterranean. From primary production estimates in the Western and Eastern Mediterranean (140-160 vs. ≈19-60 mgC m -2 d -1, respectively) it has been calculated that a carbon export from the euphotic layer to 1000 m depth is equivalent to about 10% in the Gulf of Lions and 2-3% in the Cretan Sea. Chlorophyll-a concentrations, at similar depths, were 2-3 times higher in the Western basin. Carbohydrates were the dominant biochemical component in the Cretan Sea sediments while total amino-acids represented an important fraction of the biodegradable material in the Gulf of Lions-Catalan Sea. In the Western Mediterranean, bacterial densities (annual mean 7.9×10 8 cells g -1) were about 4 times higher than in the Cretan Sea (annual mean 2.1×10 8 cells g -1), indicating that, in deep-sea sediments, different trophic

  10. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Directory of Open Access Journals (Sweden)

    Nicholas W Pilfold

    Full Text Available BACKGROUND: Polar bears (Ursus maritimus of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650 and hunting attempts on ringed seal (Pusa hispida lairs (n=1396 observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation. PRINCIPAL FINDINGS: Polar bears primarily preyed on ringed seals (90.2% while bearded seals (Erignathus barbatus only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344 of the ringed seals killed, while their pups comprised 38.4% (132/344. Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344 of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121, and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78. The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2 =0.30, P=0.04, but was not correlated with the number of adult kills (P=0.37. CONCLUSIONS/SIGNIFICANCE: Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  11. Influence of chemosynthetic ecosystems on nematode community structure and biomass in the deep eastern Mediterranean Sea

    Science.gov (United States)

    Lampadariou, N.; Kalogeropoulou, V.; Sevastou, K.; Keklikoglou, K.; Sarrazin, J.

    2013-08-01

    Mud volcanoes are a~special type of cold seeps where life is based on chemoautotrophic processes. They are considered to be extreme environments and are characterized by unique megafaunal and macrofaunal communities. However, very few studies on mud volcanoes taking into account the smaller meiobenthic communities have been carried out. Two mud volcanoes were explored during the MEDECO (MEditerranean Deep-sea ECOsystems) cruise (2007) with the remotely operated vehicle (ROV) Victor-6000: Amsterdam, located south of Turkey between 1700 and 2000 m depth (Anaximander mud field); and Napoli, south of Crete, located along the Mediterranean Ridge at about 2000 m depth (Olimpi mud field). The major aim of this study was to describe distributional patterns of meiofaunal communities and nematode assemblages from different seep microhabitats. Meiofaunal taxa and nematode assemblages at both mud volcanoes differed significantly from other Mediterranean sites in terms of standing stocks, dominance and species diversity. Density and biomass values were significantly higher at the seep sites, particularly at Amsterdam. Patterns of nematode diversity, the dominant meiofaunal taxon, varied, displaying both very high or very low species richness and dominance, depending on the microhabitat studied. The periphery of the Lamellibrachia and bivalve shell microhabitats of Napoli exhibited the highest species richness, while the reduced sediments of Amsterdam yielded a species-poor nematode community dominated by two successful species, one belonging to the genus Aponema and the other to the genus Sabatieria. Analysis of β-diversity showed that microhabitat heterogeneity of mud volcanoes contributed substantially to the total nematode species richness in the eastern Mediterranean Sea. These observations indicate a strong influence of mud volcanoes and cold-seep ecosystems on the meiofaunal communities and nematode assemblages.

  12. Influence of chemosynthetic ecosystems on nematode community structure and biomass in the deep eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    N. Lampadariou

    2013-08-01

    Full Text Available Mud volcanoes are a~special type of cold seeps where life is based on chemoautotrophic processes. They are considered to be extreme environments and are characterized by unique megafaunal and macrofaunal communities. However, very few studies on mud volcanoes taking into account the smaller meiobenthic communities have been carried out. Two mud volcanoes were explored during the MEDECO (MEditerranean Deep-sea ECOsystems cruise (2007 with the remotely operated vehicle (ROV Victor-6000: Amsterdam, located south of Turkey between 1700 and 2000 m depth (Anaximander mud field; and Napoli, south of Crete, located along the Mediterranean Ridge at about 2000 m depth (Olimpi mud field. The major aim of this study was to describe distributional patterns of meiofaunal communities and nematode assemblages from different seep microhabitats. Meiofaunal taxa and nematode assemblages at both mud volcanoes differed significantly from other Mediterranean sites in terms of standing stocks, dominance and species diversity. Density and biomass values were significantly higher at the seep sites, particularly at Amsterdam. Patterns of nematode diversity, the dominant meiofaunal taxon, varied, displaying both very high or very low species richness and dominance, depending on the microhabitat studied. The periphery of the Lamellibrachia and bivalve shell microhabitats of Napoli exhibited the highest species richness, while the reduced sediments of Amsterdam yielded a species-poor nematode community dominated by two successful species, one belonging to the genus Aponema and the other to the genus Sabatieria. Analysis of β-diversity showed that microhabitat heterogeneity of mud volcanoes contributed substantially to the total nematode species richness in the eastern Mediterranean Sea. These observations indicate a strong influence of mud volcanoes and cold-seep ecosystems on the meiofaunal communities and nematode assemblages.

  13. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Science.gov (United States)

    Pilfold, Nicholas W; Derocher, Andrew E; Stirling, Ian; Richardson, Evan; Andriashek, Dennis

    2012-01-01

    Polar bears (Ursus maritimus) of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650) and hunting attempts on ringed seal (Pusa hispida) lairs (n=1396) observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation. Polar bears primarily preyed on ringed seals (90.2%) while bearded seals (Erignathus barbatus) only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344) of the ringed seals killed, while their pups comprised 38.4% (132/344). Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344) of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121), and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78). The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2) =0.30, P=0.04), but was not correlated with the number of adult kills (P=0.37). Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  14. Fog composition at Baengnyeong Island in the eastern Yellow Sea: detecting markers of aqueous atmospheric oxidations

    Directory of Open Access Journals (Sweden)

    A. J. Boris

    2016-01-01

    Full Text Available Samples of fog water were collected at Baengnyeong Island (BYI in the Yellow Sea during the summer of 2014. The most abundant chemical species in the fog water were NH4+ (mean of 2220 µM, NO3− (1260 µM, SO4−2 (730 µM, and Na+ (551 µM, with substantial contributions from other species consistent with marine and biomass burning influence on some dates. The pH of the samples ranged between 3.48 and 5.00, with a mean of 3.94, intermediate within pH values of fog/cloud water reported previously in Southeast Asia. Back trajectories (72 h showed that high relative humidity ( >  80 % was encountered upwind of the sampling site by all but one of the sampled air masses, and that the fog composition at BYI can be impacted by several different source regions, including the Sea of Japan, southeastern China, northeastern China, and the East China Sea. Sulfur in the collected fog was highly oxidized: low S(IV concentrations were measured (mean of 2.36 µM in contrast to SO4−2 and in contrast to fog/cloud S(IV concentrations from pollutant source regions; organosulfate species were also observed and were most likely formed through aging of mainly biogenic volatile organic compounds. Low-molecular-mass organic acids were major contributors to total organic carbon (TOC; 36–69 %, comprising a fraction of TOC at the upper end of that seen in fogs and clouds in other polluted environments. Large contributions were observed from not only acetic and formic acids but also oxalic, succinic, maleic, and other organic acids that can be produced in aqueous atmospheric organic processing (AAOP reactions. These samples of East Asian fog water containing highly oxidized components represent fog downwind of pollutant sources and can provide new insight into the fate of regional emissions. In particular, these samples demonstrate the result of extensive photochemical aging during multiday transport, including oxidation within wet aerosols and

  15. The diet and feeding ecology of Conger conger (L. 1758 in the deep waters of the Eastern Ionian Sea

    Directory of Open Access Journals (Sweden)

    A. ANASTASOPOULOU

    2013-06-01

    Full Text Available The diet of the European conger eel Conger conger was investigated for the first time in the Eastern Mediterranean. Fish dominated the European conger eel diet in the deep waters of E. Ionian Sea. All other prey taxa were identified as accidental preys. However, intestine analysis showed that Natantia, Brachyura and Cephalopoda might have a more important contribution in the diet of the species. C. conger exhibited a benthopelagic feeding behavior as it preyed upon both demersal and mesopelagic taxa. The high vacuity index and the low stomach and intestine fullness indicated that the feeding intensity of the species in the deep waters of Eastern Ionian Sea was quite low. C. conger feeding strategy was characterised by specialisation in various resource items. A between-phenotype contribution to niche width was observed for some prey categories. European Conger eel feeding specialisation seemed to be an adaptation to a food-scarce environment, as typified in deep-water habitats

  16. AFSC/RACE/FBEP/Hurst: Distributional patterns of 0-group Pacific cod (Gadus macrocephalus) in the eastern Bering Sea under variable recruitment and thermal conditions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a study that analyzed the late summer distribution of juvenile Pacific cod in the eastern Bering Sea for 6 cohorts (2004-2009), based on catches...

  17. AFSC/RACE/EcoFOCI: Chlorophyll: variability in spring chlorophyll concentrations and zooplankotn on the eastern Bering Sea shelf - cruise Healy 07-01

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected under NSF Grant # ARC-0722448 ("BEST: Impacts of Sea-ice on the Hydrographic Structure, Nutrients, and Mesozooplankton over the Eastern...

  18. AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service Annual Eastern Bering Sea Summer Bottom Trawl Surveys 1975 - 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the annual NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the eastern Bering Sea continental...

  19. 16S rRNA-based bacterial diversity in the organic-rich sediments underlying oxygen-deficient waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Divya, B.; Parvathi, A.; LokaBharathi, P.A.; Nair, S.

    and diversity in OMZ sediments of the eastern Arabian Sea (AS) through 16S rRNA clone library analysis. Phylogenetic analysis of the sequences demonstrated that phylum Proteobacteria (52%), followed by Planctomycetes (12.7%), Chloroflexi and an unidentified...

  20. Seasonal Variations of Oceanographic Variables and Eastern Little Tuna (Euthynnus affinis) Catches in the North Indramayu Waters Java Sea

    Science.gov (United States)

    Syamsuddin, Mega; Sunarto; Yuliadi, Lintang

    2018-02-01

    The remotely derived oceanographic variables included sea surface temperature (SST), chlorophyll-a (Chl-a) and Eastern Little Tuna (Euthynnus affinis) catches are used as a combined dataset to understand the seasonal variation of oceanographic variables and Eastern Little Tuna catches in the north Indramayu waters, Java Sea. The fish catches and remotely sensed data were analysed for the 5 years datasets from 2010-2014. This study has shown the effect of monsoon inducing oceanographic condition in the study area. Seasonal change features were dominant for all the selected oceanographic parameters of SST and Chl-a, and also Eastern Little Tuna catches, respectively. The Eastern Little Tuna catch rates have the peak season from September to December (700 to 1000) ton that corresponded with the value of SST ranging from 29 °C to 30 °C following the decreasing of Chl-a concentrations in September to November (0.4 to 0.5) mg m-3. The monsoonal system plays a great role in determining the variability of oceanographic conditions and catch in the north Indramayu waters, Java Sea. The catches seemed higher during the northwest monsoon than in the southeast monsoon for all year observations except in 2010. The wavelet spectrum analysis results confirmed that Eastern Little Tuna catches had seasonal and inter-annual variations during 2012-2014. The SST had seasonal variations during 2010-2014. The Chl-a also showed seasonal variations during 2010-2011 and interannual variations during 2011-2014. Our results would benefit the fishermen and policy makers to have better management for sustainable catch in the study area.

  1. Variability and connectivity of plaice populations from the Eastern North Sea to the Baltic Sea, part II. Biological evidence of population mixing

    DEFF Research Database (Denmark)

    Ulrich, Clara; Hansen, Jakob Hemmer; Boje, Jesper

    2016-01-01

    in parallel. Genetic markers suggested the existence of different genetic populations in the transition area. Growth backcalculation with otoliths resulted in significant although limited differences in growth rates between North Sea and Skagerrak, indicating weak differentiation or important mixing......A multi-disciplinary study was conducted to clarify stock identity and connectivity patterns in the populations of European plaice (Pleuronectes platessa) in the Skagerrak-Kattegat transition area between the Eastern North Sea and the Baltic Sea. Five independent biological studies were carried out...... constitute a large share of the catches in this area. The mixing of different populations within a management area has implications for stock assessment and management. Choice must be made to either lump or split the populations, and the feasibility and constraints of both options are discussed. The outcomes...

  2. Distribution, density and abundance of Antarctic ice seals off Queen Maud Land and the eastern Weddell Sea

    OpenAIRE

    Gurarie, Eliezer; Bengtson, John L.; Bester, Marthán N.; Blix, Arnoldus Schytte; Cameron, Michael; Bornemann, Horst; Nordøy, Erling S.; Plötz, Joachim; Steinhage, Daniel; Boveng, Peter

    2017-01-01

    The Antarctic Pack Ice Seal (APIS) Program was initiated in 1994 to estimate the abundance of four species of Antarctic phocids: the crabeater seal Lobodon carcinophaga , Weddell seal Leptonychotes weddellii , Ross seal Ommatophoca rossii and leopard seal Hydrurga leptonyx and to identify ecological relationships and habitat use patterns. The Atlantic sector of the Southern Ocean (the eastern sector of the Weddell Sea) was surveyed by research teams from Germany, Norway and South Africa usi...

  3. Late Pliocene climate change 3.4-2.3 Ma: paleoceanographic record from the Yabuta Formation, Sea of Japan

    Science.gov (United States)

    Cronin, T. M.; Kitamura, A.; Ikeya, Noriyuki; Watanabe, M. E.; Kamiya, T.

    1994-01-01

    Late Pliocene paleoceanographic changes in the Sea of Japan between 3.4 and2.3 Ma were investigated through study of molluscs, diatoms, and ostracodes from the Yabuta Formation in Toyama Prefecture. The period 3.4-2.7 Ma was characterized by relatively high sea level and cool water benthic faunas. A progressive paleoceanographic shift towards colder oceanic conditions and lower sea level occurred beginning near 2.7 Ma, intenifying about 2.5 Ma, when important changes in ostracode and molluscan faunas occurred. Between 2.7 and 2.3 Ma, eight glacial events can be inferred based on drops in sea level of 50-60 m and increasing proportions of cold, shallow water ostracode species whose modern ecology and zoogeography indicate colder winter water temperatures (3-4??C). The glacial events between 2.5 and 2.3 Ma were the most intense. Preliminary interpretation of the faunal and oceanographic events of the Yabuta Formation suggests that they correspond to Northern Hemispheric cooling also known from North Atlantic deep-sea oxygen isotope, IRD, and planktic foraminiferal records, North Pacific diatom and radiolarian record, and the Chinese loess sequences. The eight glacial events may record a 41,000-yr obliquity cycle which characterized other late Pliocene climate proxy records. Inferred sea level drops near 2.5-2.3 Ma of about 50-60 m provide direct evidence from an ocean margin setting that supports deep sea oxygen isotopic evidence indicating major changes in global ice volume changes. ?? 1994.

  4. Enhancement of the surface methane hydrate-bearing layer based on the specific microorganisms form deep seabed sediment in Japan Sea.

    Science.gov (United States)

    Hata, T.; Yoneda, J.; Yamamoto, K.

    2017-12-01

    A methane hydrate-bearing layer located near the Japan Sea has been investigated as a new potential energy resource. In this study examined the feasibility of the seabed surface sediment strength located in the Japan Sea improvement technologies for enhancing microbial induced carbonate precipitation (MICP) process. First, the authors cultivated the specific urease production bacterium culture medium from this surface methane hydrate-bearing layer in the seabed (-600m depth) of Japan Sea. After that, two types of the laboratory test (consolidated-drained triaxial tests) were conducted using this specific culture medium from the seabed in the Japan Sea near the Toyama Prefecture and high urease activities bacterium named Bacillus pasteurii. The main outcomes of this research are as follows. 1) Specific culture medium focused on the urease production bacterium can enhancement of the urease activities from the methane hydrate-bearing layer near the Japan Sea side, 2) This specific culture medium can be enhancement of the surface layer strength, 3) The microbial induced carbonate precipitation process can increase the particle size compared to that of the original particles coating the calcite layer surface, 4) The mechanism for increasing the soil strength is based on the addition of cohesion like a cement stabilized soil.

  5. Mantle wedge structure beneath the Yamato Basin, southern part of the Japan Sea, revealed by long-term seafloor seismic observations

    Science.gov (United States)

    Shinohara, M.; Nakahigashi, K.; Yamashita, Y.; Yamada, T.; Mochizuki, K.; Shiobara, H.

    2016-12-01

    The Japanese Islands are located at subduction zones where Philippine Sea (PHS) plate subducts from the southeast beneath the Eurasian plate and the Pacific plate descends from the east beneath the PHS and Eurasian plates and have a high density of seismic stations. Many seismic tomography studies using land seismic station data were conducted to reveal the seismic structure. These studies discussed the relationship between heterogeneous structures and the release of fluids from the subducting slab, magma generation and movement in the subduction zone. However, regional tomography using the land station data did not have a sufficient resolution to image a deep structure beneath the Japan Sea.To obtain the deep structure, observations of natural earthquakes within the Japan Sea are essential. Therefore, we started the repeating long-term seismic observations using ocean bottom seismometers(OBSs) in the Yamato Basin from 2013 to 2016. We apply travel-time tomography method to the regional earthquake and teleseismic arrival-data recorded by OBSs and land stations. In this presentation, we will report the P and S wave tomographic images down to a depth of 300 km beneath the southern part of the Japan Sea. This study was supported by "Integrated Research Project on Seismic and Tsunami Hazards around the Sea of Japan" conducted by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan.

  6. Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey

    International Nuclear Information System (INIS)

    Celik, N.; Cevik, U.; Celik, A.; Koz, B.

    2009-01-01

    In the present work, naturally occurring radionuclides of 226 Ra, 232 Th and 40 K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120 Bq kg -1 for 226 Ra, from 13 to 121 Bq kg -1 for 232 Th and from 204 to 1295 Bq kg -1 for 40 K. Besides naturally occurring radionuclides, 137 Cs activity concentration was measured in soil, lichen and moss samples and it was found that 137 Cs activity concentration ranged from 27 to 775 Bq kg -1 with for soil, from 29 to 879 Bq kg -1 for lichen and from 67 to 1396 Bq kg -1 for moss samples. Annual effective doses due to the naturally occurring radionuclides and 137 Cs were estimated. Ecological half-lives of 137 Cs in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species

  7. 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.

  8. Distribution of the cyanophyte Trichodesmium (Oscillatoriaceae) in the eastern Caribbean Sea: influence of the Orinoco River.

    Science.gov (United States)

    Navarro, A; Corredor, J E; Morell, J; Armstrong, R A

    2000-12-01

    Orinoco River influence in the Caribbean Sea, characterized by high nutrient input, causes a decrease of Trichodesmium populations. The Caribbean Time Series (CaTS) station, south of Puerto Rico (17 degrees 36'N 67 degrees 00'W), was monitored for 25 months in order to observe the Trichodesmium abundance pattern and the presence of the river plume. In general, mean Trichodesmium abundance was higher at the surface and decreased with depth. The mean upper water column (surface to 20 m) abundance was 54.1 +/- 32.6 col/m3. Within the sampling period, abundance was highly variable (1-700 col/m3). Correlation between Trichodesmium abundance and wind speed (p=0.002), chlorophyll a concentration (p=0.001), nitrate (p=0.02) and silicate (p=0.003) concentrations were statistically significant. However, Trichodesmium abundance was not correlated with salinity (p=0.70), temperature (p=0.16) and seawater density (p=0.71) variations at CaTS. Eastern Caribbean regions highly influenced by the Orinoco River discharge were devoid of Trichodesmium colonies.

  9. Chelidoperca stella, a new species of perchlet (Perciformes: Serranidae) from the Andaman Sea, eastern Indian Ocean.

    Science.gov (United States)

    Matsunuma, Mizuki; Motomura, Hiroyuki

    2016-03-16

    A new species of serranid fish, Chelidoperca stella, is described on the basis of five specimens from the Andaman Sea in the eastern Indian Ocean. The species can be readily distinguished from all valid congeners by having fewer pored lateral-line scales (34 or 35 vs. 40-45 in the latter) and the pelvic fin white with several small yellow spots (vs. spots absent). The species is also characterized by having relatively high counts of small serrae on the posterior margins of the preopercle (33-43 serrae), interopercle (7-10) and subopercle (18-28), despite the small body size (51.7-61.8 mm SL). Although Chelidoperca stella resembles C. margaritifera in having 2.5 scale rows between lateral line and the sixth dorsal-fin spine base, a relatively wider interorbital region, and the interorbital scales not reaching a vertical through the orbit anterior margin, but differs by having the above-mentioned diagnostic characters plus a slightly shorter longest anal-fin soft ray [17.4-18.7 (mean 18.1) % SL vs. 22.6-26.4 (24.4) % SL in C. margaritifera].

  10. The surface circulation in the eastern basin of the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Najwa Hamad

    2006-09-01

    Full Text Available The schema of the Atlantic Water (AW, 100-200 m thick circulation in the eastern basin of the Mediterranean Sea elaborated in the 1990s (and widely referred to nowadays mainly shows jets meandering offshore across the whole basin. However, all previous schemata (since the 1910s and an analysis of infrared (IR satellite images in the 1990s show counterclockwise circulation at basin scale. A former controversy about the circulation was elucidated in the western basin where IR images helped describe the mesoscale features and demonstrate their role in the circulation. This motivated the detailed analysis of IR daily and weekly composites (~1000 from 1996 to 2000, and of monthly composites since 1985. We show that AW circulates along the upper part of the continental slope in a counterclockwise direction around the whole basin. In the south and all year long, this circulation is unstable and generates mesoscale anticyclonic eddies that spread AW offshore; in the north dense water formation induces larger seasonal variability. These mesoscale eddies, as well as the Etesian-induced eddies Ierapetra and Pelops, can be followed for years, sometimes several hundreds of km away from where they are formed, and they can merge and/or interact with the alongslope circulation.

  11. Assessment of big floods in the Eastern Black Sea Basin of Turkey.

    Science.gov (United States)

    Yüksek, Ömer; Kankal, Murat; Üçüncü, Osman

    2013-01-01

    In this study, general knowledge and some details of the floods in Eastern Black Sea Basin of Turkey are presented. Brief hydro-meteorological analysis of selected nine floods and detailed analysis of the greatest flood are given. In the studied area, 51 big floods have taken place between 1955-2005 years, causing 258 deaths and nearly US $500,000,000 of damage. Most of the floods have occurred in June, July and August. It is concluded that especially for the rainstorms that have caused significantly damages, the return periods of the rainfall heights and resultant flood discharges have gone up to 250 and 500 years, respectively. A general agreement is observed between the return periods of rains and resultant floods. It is concluded that there has been no significant climate change to cause increases in flood harms. The most important human factors to increase the damage are determined as wrong and illegal land use, deforestation and wrong urbanization and settlement, psychological and technical factors. Some structural and non-structural measures to mitigate flood damages are also included in the paper. Structural measures include dykes and flood levees. Main non-structural measures include flood warning system, modification of land use, watershed management and improvement, flood insurance, organization of flood management studies, coordination between related institutions and education of the people and informing of the stakeholders.

  12. Movement Ecology of the Reef Manta Ray Manta alfredi in the Eastern Red Sea

    KAUST Repository

    Braun, Camrin D.

    2013-07-01

    Many well-studied elasmobranch populations have recently exhibited significant decline. The limited data related to fisheries and sightings for many unstudied or poorly understood populations indicate that these are also suffering. Directed fisheries and more cryptic threats such as entanglement and vessel strike represent significant risk to mobulid rays, arguably one of the most vulnerable elasmobranch groups. Very little information currently exists describing the basic ecology of manta rays or quantifying anthropogenic threats and impacts; however, recent efforts have drastically improved the body of knowledge available for these species, including oceanographic influences on movement, seasonal migration, and mating behaviors. Nevertheless, Red Sea mantas remain completely enigmatic. In this thesis, Chapter 1 details results from tagging 18 reef manta rays Manta alfredi in the eastern Red Sea using satellite and acoustic tag technology and demonstrates that mantas occupy areas with high human traffic. The combined satellite and acoustic techniques define both regional movements and ‘hotspots’ of habitat use where there is significant potential for manta-human interaction. I also present opportunistic sighting data that corroborate anthropogenic impacts on this population. Chapter 2 explores the vertical component of the nine satellite tags that were deployed on Manta alfredi as described in the previous chapter. Seven tags returned adequate data for analysis. Three of the seven were physically recovered yielding full archival datasets of depth, temperature, and light levels every 10-15 seconds for over 2.6 5 million cumulative data points. Mantas frequented the upper 10 m during the day and occupied deeper water through nocturnal periods. Individuals also exhibited deep diving behavior as deep as 432 m, extending the known depth range of the species. An investigation of 76 high-resolution deep dives suggests gliding is a significant behavioral component of

  13. Miocene to recent tectonic and sedimentary evolution of the Anaximander Seamounts; eastern Mediterranean Sea

    Science.gov (United States)

    Cranshaw, Jennifer

    This thesis is focused on the Messinian to Recent tectonic and sedimentary evolution of the Anaximander Mountains and surrounding environs in the eastern Mediterranean Sea. It is based on processing of high-resolution seismic reflection data and the interpretation and mapping of seismic reflection profiles collected from this area during the 2001 and 2007 research cruises. The data show that the greater Anaximander Mountains region experienced a short interval of tectonic quiescence during the Messinian when a thin evaporite unit was deposited across a major erosional surface. This phase of limited tectonic activity ended in the latest Miocene and was replaced by an erosional phase. Major unconformities in the area are interpreted to develop during the desiccation of the eastern Mediterranean associated with the so-called Messinian salinity crisis. During the early Pliocene, the region experienced an increase in tectonic activity, dominated by transpression. Small amounts of growth observed in Pliocene-Quaternary sediments suggested that the tectonic activity remained low during the early Pliocene-Quaternary. However, the extensive growth strata wedges developed in older sediments indicate a period of accelerated tectonic activity during the mid-late Pliocene-Quaternary. This study suggests that the Anaximander Mountain (sensu stricto ) and the Anaximenes Mountain developed during the Pliocene-Quaternary as the result of a crustal-scale thick-skinned linked imbricate thrust fan. The development of back thrusts in both mountains heightened the seafloor morphology of these submarine mountains and brought Eocene-Oligocene sediments into the core of these mountains. The Sim Erinc Plateau represents a 30-40 km wide transpressional fault zone developed during the Pliocene-Quaternary. In this region the corrugated seafloor morphology observed in the multibeam bathymetry map is the reflection of high-angle faults. It is speculated that this transpressional fault zone

  14. Population structure in Atlantic cod in the eastern North Sea-Skagerrak-Kattegat: early life stage dispersal and adult migration.

    Science.gov (United States)

    André, Carl; Svedäng, Henrik; Knutsen, Halvor; Dahle, Geir; Jonsson, Patrik; Ring, Anna-Karin; Sköld, Mattias; Jorde, Per Erik

    2016-02-03

    In marine fish species, where pelagic egg and larvae drift with ocean currents, population structure has been suggested to be maintained by larval retention due to hydrographic structuring and by homing of adult fish to natal areas. Whilst natal homing of adults has been demonstrated for anadromous and coral reef fishes, there are few documented examples of philopatric migration in temperate marine fish species. Here, we demonstrate temporally stable genetic differentiation among spawning populations of Atlantic cod (Gadus morhua L.), and present genetic and behavioural evidence for larval drift and philopatric migration in the eastern North Sea-Skagerrak-Kattegat area. We show that juvenile cod collected in the eastern Skagerrak and central Kattegat are genetically similar to cod from offshore spawning areas in the eastern North Sea. Genetic assignment of individual 2-5 year old fish indicates that cod residing at, or migrating towards, spawning areas in Kattegat and the North Sea display philopatric behaviours. Together these findings suggest a loop between spawning, larval drift and adult return-migrations to spawning areas and underlines that both oceanographic processes and migratory behaviour in the adult phase may be important for stock separation and integrity in marine temperate fishes such as Atlantic cod.

  15. Variability of factors driving spatial and temporal dispersion in river plume and Chattonella antiqua bloom in the Yatsushiro Sea, Japan.

    Science.gov (United States)

    Aoki, Kazuhiro; Onitsuka, Goh; Shimizu, Manabu; Kuroda, Hiroshi; Matsuo, Hitoshi; Kitadai, Yuuki; Sakurada, Kiyonari; Ando, Hidenori; Nishi, Hiromi; Tahara, Yoshio

    2014-04-15

    The dynamics of river plume in relation to harmful blooms of the raphidophycean flagellate, Chattonella antiqua in summer 2008-2010 in the Yatsushiro Sea, Japan were studied using a hydrodynamic model and monitoring data. In the southern area, the bloom formed in the waters stratified by a halocline caused by the southward expansion of riverine water from the Kuma River after the bloom initially forming in the northern area. The timing of the southward riverine water advection can be explained by the balance between the wind stress term and the pressure gradient term calculated from the horizontal density difference between the northern and southern areas. The wind stress and pressure gradient terms were evaluated using the sea surface temperature, salinity, wind speed and direction at two stations. Real time monitoring or continuous observations in these areas will enable nowcasts of bloom expansion when a bloom develops in the northern area. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Growth and reproduction of the sea snake, Emydocephalus ijimae, in the central Ryukyus, Japan: a mark and recapture study.

    Science.gov (United States)

    Masunaga, Gen; Ota, Hidetoshi

    2003-04-01

    A mark and recapture study was carried out for three years on a population of the Ijima's sea snake, Emydocephalus ijimae, in the coastal shallow water of Zamamijima Island, central Ryukyus, Japan. The relatively high recapture (47% of 167 marked snakes) suggests that E. ijimae is a particularly philopatric, sedentary species among the sea snakes. The sex ratio (male: female), approximately 1.6:1, significantly skewed from 1:1. The growth rate in SVL declined with growth, with females thoroughly growing better than males. Males and females were estimated to begin reproductive activity in the second or third summer and the third spring after birth, respectively. Frequency of female reproduction is guessed to vary from annual to biennial, or even less frequent.

  17. Aerosol direct effect on solar radiation over the eastern Mediterranean Sea based on AVHRR satellite measurements

    Science.gov (United States)

    Georgakaki, Paraskevi; Papadimas, Christos D.; Hatzianastassiou, Nikos; Fotiadi, Aggeliki; Matsoukas, Christos; Stackhouse, Paul; Kanakidou, Maria; Vardavas, Ilias M.

    2017-04-01

    Despite the improved scientific understanding of the direct effect of aerosols on solar radiation (direct radiative effect, DRE) improvements are necessary, for example regarding the accuracy of the magnitude of estimated DREs and their spatial and temporal variability. This variability cannot be ensured by in-situ surface and airborne measurements, while it is also relatively difficult to capture through satellite observations. This becomes even more difficult when complete spatial coverage of extended areas is required, especially concerning areas that host various aerosol types with variable physico-chemical and optical aerosol properties. Better assessments of aerosol DREs are necessary, relying on aerosol optical properties with high spatial and temporal variation. The present study aims to provide a refined, along these lines, assessment of aerosol DREs over the eastern Mediterranean (EM) Sea, which is a key area for aerosol studies. Daily DREs are computed for 1˚ x1˚ latitude-longitude grids with the FORTH detailed spectral radiation transfer model (RTM) using input data for various atmospheric and surface parameters, such as clouds, water vapor, ozone and surface albedo, taken from the NASA-Langley Global Earth Observing System (GEOS) database. The model spectral aerosol optical depth (AOD), single scattering albedo and asymmetry parameter are taken from the Global Aerosol Data Set and the NOAA Climate Data Record (CDR) version 2 of Advanced Very High resolution Radiometer (AVHRR) AOD dataset which is available over oceans at 0.63 microns and at 0.1˚ x0.1˚ . The aerosol DREs are computed at the surface, the top-of-atmosphere and within the atmosphere, over the period 1985-1995. Preliminary model results for the period 1990-1993 reveal a significant spatial and temporal variability of DREs over the EM Sea, for example larger values over the Aegean and Black Seas, surrounded by land areas with significant anthropogenic aerosol sources, and over the

  18. Analyses of Sea Surface Height, Bottom Pressure and Acoustic Travel Time in the Japan/East Sea

    National Research Council Canada - National Science Library

    Xu, Yongsheng

    2006-01-01

    ...) was deployed in the southwestern JES for two years, from June 1999 to July 2001. The PIESs recorded hourly vertical acoustic travel time and pressure, which are respectively good proxies of baroclinic and barotropic sea level variability...

  19. Effect of a blackout in pediatric patients with home medical devices during the 2011 eastern Japan earthquake.

    Science.gov (United States)

    Nakayama, Tojo; Tanaka, Soichiro; Uematsu, Mitsugu; Kikuchi, Atsuo; Hino-Fukuyo, Naomi; Morimoto, Tetsuji; Sakamoto, Osamu; Tsuchiya, Shigeru; Kure, Shigeo

    2014-02-01

    during the eastern Japan earthquake in 2011 and the following prolonged blackout, pediatric patients with home medical devices sought electricity at the pediatric department. We retrospectively studied the effect of this earthquake and the following blackout. we hand-reviewed pediatric admission records in Tohoku University Hospital for new inpatients attributed to the earthquake from March 11, 2011 to April 12, 2011. A survey by questionnaire regarding the situation during the earthquake was performed for parents of technology-assisted patients. during the study period, 24 pediatric patients were admitted to the pediatric department. Eighteen technology-assisted pediatric patients, including those with home respirators, accounted for 75% of new pediatric admissions. Patients who were admitted for electricity shortage stayed in the hospital for a mean of 11.0days (3-25days). The questionnaire survey showed that 55% of technology-assisted patients were admitted to medical centers for evacuation. The majority of patients (89%) with ventilators were eventually admitted to medical centers during the earthquake. Most of the parents of technology-assisted patients experienced a prolonged petrol shortage and difficulty in communications with medical centers. the current study suggests that technology-assisted pediatric patients with neurological disorders as the primary disease can overwhelm the capacity of hospital inpatient facilities in certain situations. Disaster preparedness should consider assuring power requirements in healthcare facilities and preparing backup power generators lasting for at least 24h for these patients. Preparing alternative measures for emergent electricity and communications could remedy serious conditions during a disaster. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  20. A new hybrid model for filling gaps and forecast in sea level: application to the eastern English Channel and the North Atlantic Sea (western France)

    Science.gov (United States)

    Turki, Imen; Laignel, Benoit; Kakeh, Nabil; Chevalier, Laetitia; Costa, Stephane

    2015-04-01

    This research is carried out in the framework of the program Surface Water and Ocean Topography (SWOT) which is a partnership between NASA and CNES. Here, a new hybrid model is implemented for filling gaps and forecasting the hourly sea level variability by combining classical harmonic analyses to high statistical methods to reproduce the deterministic and stochastic processes, respectively. After simulating the mean trend sea level and astronomical tides, the nontidal residual surges are investigated using an autoregressive moving average (ARMA) methods by two ways: (1) applying a purely statistical approach and (2) introducing the SLP in ARMA as a main physical process driving the residual sea level. The new hybrid model is applied to the western Atlantic sea and the eastern English Channel. Using ARMA model and considering the SLP, results show that the hourly sea level observations of gauges with are well reproduced with a root mean square error (RMSE) ranging between 4.5 and 7 cm for 1 to 30 days of gaps and an explained variance more than 80 %. For larger gaps of months, the RMSE reaches 9 cm. The negative and the positive extreme values of sea levels are also well reproduced with a mean explained variance between 70 and 85 %. The statistical behavior of 1-year modeled residual components shows good agreements with observations. The frequency analysis using the discrete wavelet transform illustrate strong correlations between observed and modeled energy spectrum and the bands of variability. Accordingly, the proposed model presents a coherent, simple, and easy tool to estimate the total sea level at timescales from days to months. The ARMA model seems to be more promising for filling gaps and estimating the sea level at larger scales of years by introducing more physical processes driving its stochastic variability.

  1. Indian Monsoon and denitrification change in the Laxmi Basin (IODP Exp. 355 Site U1456) of the Eastern Arabian Sea during the last 800 kyrs

    Science.gov (United States)

    Kim, J. E.; Khim, B. K.; Ikehara, M.; Lee, J.

    2017-12-01

    The Arabian Sea is a famous site for the basin-wide denitrification in the globe. The Western Arabian Sea has been acknowledged by its upwelling-induced denitrification related to the Indian Monsoon system (Altabet et al., 1999). It was recently reported that the denitrification in the Eastern Arabian Sea (IODP Exp. 355 Site U1456) has been persistent and consistent during the mid-Pleistocene as reflected in the bulk sediment δ15N values (Tripathi et al., 2017). Based on the age model reconstructed by δ18O stratigraphy of planktonic foraminifera (Globigerinoides ruber) together with shipboard biostratigraphic and paleomagnetic data at Site U1456 drilled in the Laxmi Basin of the Eastern Arabian Sea, the glacial-interglacial fluctuations of denitrification in association with the development of oxygen minimum zone (OMZ) were resolved in the context of Indian Monsoon activity. One of striking features in the Eastern Arabian Sea is that the δ15N values of bulk sediment show clear and consistent denitrification with minimum δ15N values exceeding 6‰ even during glacial periods, when its western counterpart experienced a temporal collapse of OMZ and denitrification. The Eastern Arabian Sea is fed not only by the upwelling-induced productivity in the western margin during the summer monsoon but also by the high productivity during the winter monsoon, both of which maintain the increased productivity affecting the OMZ through the consumption of dissolved oxygen by the degradation of sinking organic particles. The Eastern Arabian Sea is further influenced by the clockwise surface currents, intermediate water ventilation change by the blockage of Antarctic Intermediate Water, limited inflow from the Red Sea/Persian Gulf, and the freshwater salinity stratification due to nearby riverine discharges, all of which make the denitrification process more complicated than the Western Arabian Sea. Nonetheless, the glacial-interglacial denitrification change in the Eastern

  2. Currents and transport on the Eastern Bering Sea shelf: An integration of over 20 years of data

    Science.gov (United States)

    Stabeno, P. J.; Danielson, S. L.; Kachel, D. G.; Kachel, N. B.; Mordy, C. W.

    2016-12-01

    More than 20 years of data from moorings, satellite-tracked drifters and hydrographic surveys are integrated to provide a comprehensive view of currents and transport on the eastern Bering Sea shelf. The major sources of water onto the eastern Bering Sea shelf are North Pacific water flowing through Unimak Pass and Bering Slope water flowing onto the shelf usually via the canyons that intersect the shelf break. Absolute geostrophic transport through Unimak Pass varies from an average of 0.25×106 m3 s-1 (Sv) in the warm months to 0.43 Sv in the cold months. Flow along the 50-m isobath is weak, with a transport of Unimak Pass to Bering Strait is >13 months and from Amukta Pass to Bering Strait via the Bering Slope Current is >8 months. Consequently, the source of most of the heat transported into the Arctic through Bering Strait is a result of air-sea interactions local to the northern Bering Sea. Analysis of the currents and water properties on the southern shelf indicates that 50% of the shelf water is exchanged with slope water during October-January each year. This exchange elevates the October mid-shelf average nitrate level from 6 μM to 14-16 μM by the end of January.

  3. On the forcing mechanisms of mesocyclones in the eastern Weddell Sea region, Antarctica: Process studies using a mesoscale numerical model

    Directory of Open Access Journals (Sweden)

    Thomas Klein

    2001-04-01

    Full Text Available Development mechanisms of Antarctic mesocyclones in the eastern Weddell Sea area are examined by means of simulations with a mesoscale model using different idealized initial conditions. In one of the experiments, a mesocyclone develops over an area of open water close to the coast of the Antarctic continent. The forcing mechanisms of this mesocyclogenesis are investigated by means of sensitivity studies in which certain physical processes and the relevance of the surface conditions topography, sea surface temperature and sea ice coverage are examined. The sensitivity experiments show that the simulated mesocyclone is forced by an interaction of several forcing mechanisms at different stages of the development rather than by a single mechanism. The topography of the eastern Weddell Sea region and the summertime coastal polynia are shown to be of great importance for the mesocyclogenesis. A suitable synoptic-scale flow is necessary to support the katabatic flow over the sloped ice sheet, and to enhance the generation of cyclonic vorticity due to vertical stretching for the initial mesocyclogenesis. The diabatic process of the convergence of the sensible and latent heat fluxes in the boundary layer over the coastal polynia then becomes the dominant forcing mechanism for the further development of the mesocyclone.

  4. 40Ar-39Ar dating of terrestrial and exterrestrial materials. Basalts from the Japan Sea floor, Deccan Plateau and meteorites from Antarctica

    International Nuclear Information System (INIS)

    Kaneoka, Ichiro; Takigami, Yutaka.

    1994-01-01

    Through a series of 40 Ar- 39 Ar dating for terrestrial and exterrestrial samples, the results for basalts from the Japan Sea floor, Deccan Plateau and for meteorites from Antarctica give significant information concerning their formation histories. 40 Ar- 39 Ar ages of basalts from the Japan Sea floor give a constraint that the Japan Sea floor was formed at least 20 Ma. 40 Ar- 39 Ar ages for dyke samples from the Deccan Plateau indicate a possibility for the occurrence of a little younger ages than that of the main plateau formations by a few million years. Meteorites collected from Antarctica show some variable 40 Ar- 39 Ar ages reflecting their different thermal histories. (author)

  5. Last Interglacial (Eemian) hydrographic conditions in the south-eastern Baltic Sea, NE Europe, based on dinoflagellates and pollen

    DEFF Research Database (Denmark)

    Head, Martin J.; Seidenkrantz, Marit Solveig Louise Schramm; Janczyk-Kopikowa, Zofia

    2005-01-01

    of arctic waters. Warm and saline conditions of 15–20 psu or more, at least twice present levels, persisted throughout the early Eemian. A rise in sea level at Licze appears to correlate with a similar event in eastern Denmark, as both coincide with the increase in Corylus (ca. 750 years...... into the interglacial). This sea-level rise might therefore have a basinwide extent, and has been attributed to an opening of the Danish Belts. Whereas dinoflagellate cysts reflect sustained high salinites within the upper water column, a concomitant increase in abundance of the chlorococcalean alga Pediastrum within......A rich organic-walled dinoflagellate cyst and pollen record from the Licze borehole in northern Poland has been used to reconstruct the hydrographic history of the southeastern Baltic Sea during the Eemian Stage (Last Interglacial) of the Upper Pleistocene. Warm and saline waters (ca. 10–15 psu...

  6. 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.

  7. 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.

  8. Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

    Science.gov (United States)

    Eelsalu, Maris; Soomere, Tarmo

    2016-04-01

    The risks and damages associated with coastal flooding that are naturally associated with an increase in the magnitude of extreme storm surges are one of the largest concerns of countries with extensive low-lying nearshore areas. The relevant risks are even more contrast for semi-enclosed water bodies such as the Baltic Sea where subtidal (weekly-scale) variations in the water volume of the sea substantially contribute to the water level and lead to large spreading of projections of future extreme water levels. We explore the options for using large ensembles of projections to more reliably evaluate return periods of extreme water levels. Single projections of the ensemble are constructed by means of fitting several sets of block maxima with various extreme value distributions. The ensemble is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. A hindcast by the Rossby Centre Ocean model is sampled with a resolution of 6 h and a similar hindcast by the circulation model NEMO with a resolution of 1 h. As the annual maxima of water levels in the Baltic Sea are not always uncorrelated, we employ maxima for calendar years and for stormy seasons. As the shape parameter of the Generalised Extreme Value distribution changes its sign and substantially varies in magnitude along the eastern coast of the Baltic Sea, the use of a single distribution for the entire coast is inappropriate. The ensemble involves projections based on the Generalised Extreme Value, Gumbel and Weibull distributions. The parameters of these distributions are evaluated using three different ways: maximum likelihood method and method of moments based on both biased and unbiased estimates. The total number of projections in the ensemble is 40. As some of the resulting estimates contain limited additional information, the members of pairs of projections that are highly correlated are assigned weights 0.6. A comparison of the ensemble-based projection of

  9. Gradient measurements of gaseous elemental mercury (Hg0) in the marine boundary layer of the northwest Sea of Japan (East Sea).

    Science.gov (United States)

    Kalinchuk, Viktor; Lopatnikov, Evgeny; Astakhov, Anatoly

    2017-12-06

    Gaseous elemental mercury (Hg 0 ) is a prolific and persistent contaminant in the atmosphere. Atmospheric concentrations of Hg 0 were determined from 17 September to 7 October 2015 in the northwest Sea of Japan aboard the Russian research vessel Professor Gagarinsky. Simultaneous measurements of Hg 0 concentrations were performed 2 m and 20 m above the sea surface using automatic Hg 0 analysers RA-915M and RA-915+, respectively. Concentrations ranged from 0.3 to 25.9 ng/m 3 (n = 5207) and from 0.3 to 27.8 ng/m 3 (n = 4415), with medians of 1.7 and 1.6 ng/m 3 , respectively. Elevated Hg 0 was observed during three episodes from 19 to 22 September, likely caused by one or more of the following factors: 1) atmospheric transport of Hg 0 from the west and south-west (from N. Korea, China, and the Yellow Sea region); 2) Hg 0 emission from the sea due to pollution by water from the Tumannaya River; or 3) underwater geological activities. Increased Hg 0 concentration was observed during periods when air masses flowed from the south, and low concentrations were observed when air masses came from the north. A daytime increase of Hg 0 concentrations at a height of 2 m occurred simultaneously with decreasing Hg 0 at a height of 20 m. These diurnal variations suggest that two contrasting processes occur during the daytime in the marine boundary layer (MBL): Hg 0 emission from the sea surface and Hg 0 oxidation in the MBL by active halogens formed by photolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Menes caldera, a highly active site of brine seepage in the Eastern Mediterranean Sea: "In situ" observations from the NAUTINIL expedition

    NARCIS (Netherlands)

    Huguen, C.; Foucher, J.-P.; Mascle, J.; Ondreas, H.; Thouement, M.; Gontharet, S.; Stadnitskaia, A.; Pierre, C; Bayon, G.; Loncke, L; Boetius, A.; Bouloubassi, I.; de Lange, G.; Caprais, J.-C.; Fouquet, Y.; Woodside, J.M.; Dupre, S.

    2009-01-01

    This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven

  11. Synoptic characteristics of heavy snowfalls at Busan of Korea caused by polar lows over the East/Japan Sea

    Science.gov (United States)

    Choi, Jae-Won; Cha, Yumi; Kim, Hae-Dong

    2018-02-01

    The results of the present study prove that snowfall occurred due to the polar low (PL) in the Korean Peninsula and six cases of snowfall exceeding a snow depth of 2 cm over the past 16 years in Busan, South Korea. A strong northwesterly air current with a cold outbreak at the lower level passed through the Korean Peninsula and penetrated into the East/Japan Sea causing the generation and characteristics of a PL. However, a northeasterly air current due to a synoptic low (SL) in East Japan approached the east coast via the East/Japan Sea, which generated a wind field with mesoscale cyclonic circulation. In the center of this cyclone, a strong positive vorticity region was revealed from the lower level to the upper level. The air temperature in the center of the PL was warmer than the surrounding areas at the lower level. As the PL developed and the air temperature decreased, a rapid tropopause drop followed due to the effect of the cold core along with the cutoff low at the mid-level or the higher level. As a result, the stratification became more unstable. The PL moved into Busan as the cold core at the upper level rapidly moved to the lower latitudes, which formed an unstable region around Busan. The PL decayed because the cutoff low, the cold core, and the positive vorticity region at the upper level quickly moved to the east, thereby causing the stratification to stabilize. Also, because the approach to the Japanese Archipelago caused an increase in surface friction, the original structure could no longer be maintained.

  12. Mesopelagic Prokaryotes Alter Surface Phytoplankton Production during Simulated Deep Mixing Experiments in Eastern Mediterranean Sea Waters

    Directory of Open Access Journals (Sweden)

    Or Hazan

    2018-01-01

    Full Text Available Mesopelagic prokaryotes (archaea and bacteria, which are transported together with nutrient-rich intermediate-water to the surface layer by deep convection in the oceans (e.g., winter mixing, upwelling systems, can interact with surface microbial populations. This interaction can potentially affect production rates and biomass of surface microbial populations, and thus play an important role in the marine carbon cycle and oceanic carbon sequestration. The Eastern Mediterranean Sea (EMS is one of the most oligotrophic and warm systems in the world's oceans, with usually very shallow winter mixing (<200 m and lack of large-size spring algal blooms. In this study, we collected seawater (0–1,500 m in 9 different cruises at the open EMS during both the stratified and the mixed seasons. We show that the EMS is a highly oligotrophic regime, resulting in low autotrophic biomass and primary productivity and relatively high heterotrophic prokaryotic biomass and production. Further, we simulated deep water mixing in on-board microcosms using Levantine surface (LSW, ~0.5 m and intermediate (LIW, ~400 m waters at a 9:1 ratio, respectively and examined the responses of the microbial populations to such a scenario. We hypothesized that the LIW, being nutrient-rich (e.g., N, P and a “hot-spot” for microbial activity (due to the warm conditions that prevail in these depths, may supply the LSW with not only key-limiting nutrients but also with viable and active heterotrophic prokaryotes that can interact with the ambient surface microbial population. Indeed, we show that LIW heterotrophic prokaryotes negatively affected the surface phytoplankton populations, resulting in lower chlorophyll-a levels and primary production rates. This may be due to out-competition of phytoplankton by LIW populations for resources and/or by a phytoplankton cell lysis via viral infection. Our results suggest that phytoplankton in the EMS may not likely form blooms, even after

  13. New techniques on oil spill modelling applied in the Eastern Mediterranean sea

    Science.gov (United States)

    Zodiatis, George; Kokinou, Eleni; Alves, Tiago; Lardner, Robin

    2016-04-01

    Small or large oil spills resulting from accidents on oil and gas platforms or due to the maritime traffic comprise a major environmental threat for all marine and coastal systems, and they are responsible for huge economic losses concerning the human infrastructures and the tourism. This work aims at presenting the integration of oil-spill model, bathymetric, meteorological, oceanographic, geomorphological and geological data to assess the impact of oil spills in maritime regions such as bays, as well as in the open sea, carried out in the Eastern Mediterranean Sea within the frame of NEREIDs, MEDESS-4MS and RAOP-Med EU projects. The MEDSLIK oil spill predictions are successfully combined with bathymetric analyses, the shoreline susceptibility and hazard mapping to predict the oil slick trajectories and the extend of the coastal areas affected. Based on MEDSLIK results, oil spill spreading and dispersion scenarios are produced both for non-mitigated and mitigated oil spills. MEDSLIK model considers three response combating methods of floating oil spills: a) mechanical recovery using skimmers or similar mechanisms; b) destruction by fire, c) use of dispersants or other bio-chemical means and deployment of booms. Shoreline susceptibility map can be compiled for the study areas based on the Environmental Susceptibility Index. The ESI classification considers a range of values between 1 and 9, with level 1 (ESI 1) representing areas of low susceptibility, impermeable to oil spilt during accidents, such as linear shorelines with rocky cliffs. In contrast, ESI 9 shores are highly vulnerable, and often coincide with natural reserves and special protected areas. Additionally, hazard maps of the maritime and coastal areas, possibly exposed to the danger on an oil spill, evaluate and categorize the hazard in levels from low to very high. This is important because a) Prior to an oil spill accident, hazard and shoreline susceptibility maps are made available to design

  14. Grains of Nonferrous and Noble Metals in Iron-Manganese Formations and Igneous Rocks of Submarine Elevations of the Sea of Japan

    Science.gov (United States)

    Kolesnik, O. N.; Astakhova, N. V.

    2018-01-01

    Iron-manganese formations and igneous rocks of submarine elevations in the Sea of Japan contain overlapping mineral phases (grains) with quite identical morphology, localization, and chemical composition. Most of the grains conform to oxides, intermetallic compounds, native elements, sulfides, and sulfates in terms of the set of nonferrous, noble, and certain other metals (Cu, Zn, Sn, Pb, Ni, Mo, Ag, Pd, and Pt). The main conclusion that postvolcanic hydrothermal fluids are the key sources of metals is based upon a comparison of the data of electron microprobe analysis of iron-manganese formations and igneous rocks dredged at the same submarine elevations in the Sea of Japan.

  15. Evaluating the impact of atmospheric depositions on springtime dinitrogen fixation in the Cretan Sea (Eastern Mediterranean - A mesocosm approach

    Directory of Open Access Journals (Sweden)

    Eyal Rahav

    2016-09-01

    Full Text Available Large amounts of dust and atmospheric aerosols, originating from surrounding desert areas (e.g., Sahara and Middle East are deposited annually on the surface of the Eastern Mediterranean Sea. These depositions can provide high amounts of micro (such as Fe, Zn, Co and macro nutrients (such as P and N to supplement nutrient-poor surface waters- that typically limit primary productivity and also dinitrogen (N2 fixation in many marine environments. Here, we studied the impact of the atmospheric deposition of dust and aerosols on N2 fixation in the Cretan Sea (Eastern Mediterranean Sea. Mixed polluted aerosols (hereafter A and Saharan dust (hereafter SD were added to nine mesocosms (3-m3 each containing surface mixed layer seawater (~10 m, and N2 fixation was evaluated for 6 days during May 2012 (springtime. The addition of SD triggered a rapid (30 h and robust (2-4 fold increase in N2 fixation rates that remained high for 6 days and contributed 3-8% of the primary productivity. The A addition also resulted in higher N2 fixation rates compared to the unamended control mesocosms, although the responses were less profound (1.5-2 fold and accounted for only 2-4% of the primary productivity. The microbial community responded differently to the two additions. Heterotrophic bacterial N2 fixers dominated the diazotroph community in A and the control mesocosms, while the non-filamentous cyanobacterial group Trichodesmium prevailed in the SD treatment (68% of all the operational taxonomic units, verified by qPCR analyses. Our results indicate that the aerosol source, its route prior to deposition, and its specific chemical composition, can alter the diazotrophic diversity and activity in the Eastern Mediterranean Sea and may thus impact both the N and C dynamics in this impoverished environment.

  16. Variation of total organic carbon content along the stream Harsit, Eastern Black Sea Basin, Turkey.

    Science.gov (United States)

    Bayram, Adem; Önsoy, Hizir; Akinci, Görkem; Bulut, Volkan Numan

    2011-11-01

    The TOC in surface waters and wastewater is an important analytical parameter describing the total content of all organic substances containing carbon. In practice, the TOC originated from natural and anthropogenic sources, and even if it is not directly responsible for dangers on human health, its determination is important for any kind of water that is used by public. The aim of this study was to determine variation of total organic carbon (TOC) and total carbon (TC) content in the stream Harsit, which courses in Eastern Black Sea Region, Turkey. Sampling was fortnightly conducted in each of the four seasons between March 2009 and February 2010. A total of 230 water samples were collected from ten sampling stations along the main branch of the stream Harsit with 143 km of length. Obtained TOC values were evaluated and used to classify the water quality of stream Harsit, according to the Turkish Water Pollution Control Regulation (TWPCR). The annual average TOC content values for the stations were found between 2.33 and 6.97 mg/L. It was seen that the TOC content have increased along the streamcourse of Harsit until the fourth station, where reaches its maximum value. The TOC content, then, has decreased and the minimum value was observed in the eighth station. The results showed that, except in winter season, maximum TOC content observed in many of the water samples were above Class I water standard indicated in TWPCR, which classifies the water resources according to the different area of uses. It was also found that TOC has a small contribution to TC and the highest TOC content in stream waters were measured in Gumushane station where direct discharge of city wastewaters and solid waste dumping to the stream were observed.

  17. Distribution of slab-derived fluids around the edge of the Philippine Sea Plate from Central to Northeast Japan

    Science.gov (United States)

    Nakamura, Hitomi; Iwamori, Hikaru; Ishizuka, Osamu; Nishizawa, Tatsuji

    2018-01-01

    Marginal parts of a plate and subducting slab can play important roles in geodynamics. This is because in areas where a plate interacts with other plates or with the mantle thermal, geochemical, and mechanical interactions are expected. The Philippine Sea (PHS) slab that subducts beneath the Japan arcs has such an edge. To examine the relationship between arc magmatism and the slab edge in the transition zone from Northeast Japan to Central Japan, we investigated isotopic systematics of the regional volcanic rocks, incorporating data from literature and new data for five isotopic ratios of Sr, Nd, and Pb. The new data included major element compositions of 22 samples from the back-arc area, and 5 isotopic ratios for 6 samples selected from Pleistocene to early Quaternary epochs. Consequently, several findings were determined based on the spatial variation of the isotopic ratios and the estimated amount of slab-derived fluid: (1) the amount of fluid derived from the two subducting slabs (i.e., the Pacific slab and the PHS slab) decreases northward from a significantly high value ( 5 wt% fluid added to the source mantle), away from the seismically determined edge of the PHS slab; (2) the proportion of the PHS component in the total slab-derived fluid also decays northward; and (3) the PHS component spreads to the north beyond the seismically determined edge of the PHS slab. These observations strongly suggest that the existence of an aseismic PHS slab beneath southernmost parts of Northeast Japan delivers the PHS component to the arc magmatism. As was indicated by previous geodynamical studies, subduction of the PHS and PAC slabs may generate suction force towards the corner of mantle wedge, which might account for the large amount of fluid near the seismically determined slab edge as described in (1) above.

  18. Numerical Simulation of Heavy Rainfall in August 2014 over Japan and Analysis of Its Sensitivity to Sea Surface Temperature

    Directory of Open Access Journals (Sweden)

    Yuki Minamiguchi

    2018-02-01

    Full Text Available This study evaluated the performance of the Weather Research and Forecasting (WRF model version 3.7 for simulating a series of rainfall events in August 2014 over Japan and investigated the impact of uncertainty in sea surface temperature (SST on simulated rainfall in the record-high precipitation period. WRF simulations for the heavy rainfall were conducted for six different cases. The heavy rainfall events caused by typhoons and rain fronts were similarly accurately reproduced by three cases: the TQW_5km case with grid nudging for air temperature, humidity, and wind and with a horizontal resolution of 5 km; W_5km with wind nudging and 5-km resolution; and W_2.5km with wind nudging and 2.5-km resolution. Because the nudging for air temperature and humidity in TQW_5km suppresses the influence of SST change, and because W_2.5km requires larger computational load, W_5km was selected as the baseline case for a sensitivity analysis of SST. In the sensitivity analysis, SST around Japan was homogeneously changed by 1 K from the original SST data. The analysis showed that the SST increase led to a larger amount of precipitation in the study period in Japan, with the mean increase rate of precipitation being 13 ± 8% K−1. In addition, 99 percentile precipitation (100 mm d−1 in the baseline case increased by 13% K−1 of SST warming. These results also indicate that an uncertainty of approximately 13% in the simulated heavy rainfall corresponds to an uncertainty of 1 K in SST data around Japan in the study period.

  19. Growth and Reproduction of the Sea Snake, Emydocephalus ijimae, in the Central Ryukyus, Japan : a Mark and Recapture Study(Ecology)

    OpenAIRE

    Gen, Masunaga; Hidetoshi, Ota; Graduate School of Science and Engeneering, University of the Ryukyus; Tropical Biosphere Research Center, University of the Ryukyus

    2003-01-01

    A mark and recapture study was carried out for three years on a population of the Ijima's sea snake, Emydocephalus ijimae, in the coastal shallow water of Zamamijima Island, central Ryukyus, Japan. The relatively high recapture (47% of 167 marked snakes) suggests that E. ijimae is a particularly philopatric, sedentary species among the sea snakes. The sex ratio (male: female), approximately 1.6:1, significantly skewed from 1:1. The growth rate in SVL declined with growth, with females thoroug...

  20. Speciation of Suspended Particles By Individual Particle Analysis In The Japan Sea And The Western Tropical Pacific Ocean

    Science.gov (United States)

    Nakaguchi, Y.; Asatani, T.; Fujita, A.; Kabuki, J.; Shitashima, K.

    2008-12-01

    Trace elements such as Fe, Cd, Ni, Cu, Zn and Co are called "gbioactive trace metal"h. Reports have been made on bioactive trace metals distribution in sea water for various ocean: the North Pacific (Bruland, 1980; Boyle et al., 1981; Bruland et al., 1994; Ezoe, 2004;), the North Atlantic (Boyle et al., 1981; Bruland and Franks, 1983) and the South China Sea (Wen et al., 2006). The most of bioactive trace metals are taken up by marine organisms such as phytoplankton and bacteria. Consumption and decomposition of particulate matter sinking from surface waters return the bioactive trace metals to solution. On the other hand, some suspended particulate matters come from terrestrial sources transported to the ocean by rivers and by winds in particulate forms, and by rivers in dissolved forms. The bulk composition of suspended particulate matter in the various oceans is well known, whereas, the speciation of elements in suspended particle still remains poorly known. Individual particulate analysis can provide detailed information about the source, formation, transport and reactions of suspended particulate matter. The purpose of this work (1) the determination of dissolved bioactive trace metals (Fe, Co, Ni, Cu, Zn and Cd) in the Japan Sea and the western tropical Pacific Ocean by using the commercial PAPC type chelating resin solid phase extraction with ICP-MS method, (2) investigation for source of bioactive trace metals by the speciation of suspended particles by individual particulate analysis.

  1. Interannual Variation of Surface Circulation in the Japan/East Sea due to External Forcings and Intrinsic Variability

    Science.gov (United States)

    Choi, Byoung-Ju; Cho, Seong Hun; Jung, Hee Seok; Lee, Sang-Ho; Byun, Do-Seong; Kwon, Kyungman

    2018-03-01

    The interannual variation of surface ocean currents can be as large as seasonal variation in the Japan/East Sea (JES). To identify the major factors that cause such interannual variability of surface ocean circulation in the JES, surface circulation was simulated from 1998 to 2009 using a three-dimensional model. Contributions of atmospheric forcing (ATM), open boundary data (OBC), and intrinsic variability (ITV) of the surface flow in the JES on the interannual variability of surface ocean circulation were separately examined using numerical simulations. Variability in surface circulation was quantified in terms of variance in sea surface height, 100-m depth water temperature, and surface currents. ITV was found to be the dominant factor that induced interannual variabilities of surface circulation, the main path of the East Korea Warm Current (EKWC), and surface kinetic energy on a time scale of 2-4 years. OBC and ATM were secondary factors contributing to the interannual variation of surface circulation. Interannual variation of ATM changed the separation latitude of EKWC and increased the variability of surface circulation in the Ulleung Basin. Interannual variation of OBC enhanced low-frequency changes in surface circulation and eddies in the Yamato Basin. It also modulated basin-wide uniform oscillations of sea level. This study suggests that precise estimation of initial conditions using data assimilation is essential for long-term prediction of surface circulation in the JES.

  2. GHRSST Level 4 ODYSSEA Eastern Central Pacific Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  3. Extending the Instrumental Record of Sea-Level Change: A 1300-Year Sea-Level Record From Eastern Connecticut

    Science.gov (United States)

    Donnelly, J. P.; Cleary, P.

    2002-12-01

    The instrumental record of sea-level change in the northeastern United States extends back to the early 20th century and at New York City (NYC) extends back to 1856. These tide gauge records indicate that sea level has risen at a rate of 2.5 to 4 mm/year over the last 100-150 years. Geologic evidence of sea-level change in the region over the last 2,000 years indicates rates of sea-level rise of about 1 mm/year or less. The discordance between the instrumental and geologic records is frequently cited as potentially providing evidence that anthropogenic warming of the climate system has resulted in an increase in the rate of sea-level rise. In order to begin to test the hypothesis that acceleration in the rate of sea-level rise has occurred in the last 150 years due to anthropogenic climate warming, accurate and precise information on the timing of the apparent acceleration in sea-level rise are needed. Here we construct a high-resolution relative sea-level record for the past 1350 years by dating basal salt marsh peat samples above a glacial erratic in a western Connecticut salt marsh. Preservation of marsh vegetation remains in the sediment record that has a narrow vertical habitat range at the upper end of the tidal range provides information on past sea levels. { \\it Spartina patens} (marsh hay) and { \\it Juncus gerardi} (black rush) dominate both the modern marsh and their remains are the major constituent of the marsh sediments and occur in the modern marsh between mean high water (MHW) and mean highest high water. We use the elevation distribution of modern plant communities to estimate the relationship of sediment samples to paleo-mean high water. The chronology is based on 15 radiocarbon ages, supplemented by age estimates derived from the horizons of industrial Pb pollution and pollen indicative of European land clearance. Thirteen of the radiocarbon ages and the Pb and pollen data come from samples taken along a contact between marsh peat and a glacial

  4. Land-Sea relationships of climate-related records: example of the Holocene in the eastern Canadian Arctic and Greenland

    Science.gov (United States)

    de Vernal, Anne; Fréchette, Bianca; Hillaire-Marcel, Claude

    2017-04-01

    Anne de Vernal, Bianca Fréchette, Claude Hillaire-Marcel Important progresses have been made to reconstruct climate and ocean changes through time. However, there is often a hiatus between the land-based climate reconstructions and paleoceanographical data. The reconstructed parameters are not the same (e.g. surface air temperature vs. sea-surface temperature). Moreover, the spatial (local to regional) and temporal dimensions (seasonal, annual to multi-decadal) of proxy-data are often inconsistent, thus preventing direct correlation of time series and often leading to uncertainties in multi-site, multi-proxy compilations. Here, we address the issue of land-sea relationships in the eastern Canadian Arctic-Baffin Bay-Labrador Sea-western Greenland based on the examination of different climate-related information from marine cores (dinocysts) collected nearshore vs. offshore, ice cores (isotopes), fjord and lake data (pollen). The combined information tends to indicate that "climate" changes are not easily neither adequately captured by temperature and temperature shifts. However, the seasonal contrast of temperatures seems to be a key parameter. Whereas it is often attenuated offshore, it is generally easy to reconstruct nearshore, where water stratification is usually stronger. The confrontation of data also shows a relationship between ice core data and sea-ice cover and/or sea-surface salinity, suggesting that air-sea exchanges in basins surrounding ice sheets play a significant role with respect to their isotopic composition. On the whole, combined onshore-offshore data consistently suggest a two-step shift towards optimal summer and winter conditions the circum Baffin Bay and northern Labrador Sea at 7.5 and 6 ka BP. These delayed optimal conditions seem to result from ice-meltwater discharges maintaining low salinity conditions in marine surface waters and thus a strong seasonality.

  5. Aerosol sources and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime

    Directory of Open Access Journals (Sweden)

    J. Sciare

    2003-01-01

    Full Text Available A detailed study on the temporal variability of compounds important in controlling aerosol chemical composition was performed during a one-month experiment conducted during summer 2000 at a background site on Crete, in the Eastern Mediterranean Sea. Contribution of different aerosol sources in the Eastern Mediterranean Basin could be investigated at this location since the site is influenced by a wide range of air masses originating mainly in Europe and Africa. Chemical apportionment was performed for various air mass origins and showed a strong impact of anthropogenic emissions in the Turkey and Central Europe sectors, with black carbon (BC and non-sea-salt sulfate (nss-SO4 concentrations higher than observed in the Eastern and Western Europe sectors. High levels of non-sea-salt calcium (nss-Ca were associated with air masses from Africa but also from Central Turkey. Evidence was found that BC calculation based on light absorbance during dust events was biased. This quality-controlled high temporal resolution dataset allowed to investigate in detail the source-receptor relationships responsible for the levels of BC, nss-SO4 and sulfur dioxide (SO2, observed in Crete. Among the results obtained from this model, the major contribution of Turkey and Central Europe was confirmed in terms of anthropogenic emissions. Comparisons with remote optical properties obtained from Satellite observations (SEAWIFS north of Crete indicates that our ground based aerosol characterization was suitable for describing aerosol properties in the atmospheric column for most of the time during the campaign.

  6. Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

    Science.gov (United States)

    Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

    2017-04-01

    Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

  7. 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 MIRAI in the East China Sea, Japan Sea and others from 2005-10-31 to 2006-01-30 (NODC Accession 0109919)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109919 includes chemical, discrete sample, physical and profile data collected from MIRAI in the East China Sea (Tung Hai), Japan Sea, North Pacific...

  8. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from MIRAI in the Japan Sea, North Pacific Ocean and Sea of Okhotsk from 2006-08-01 to 2006-08-20 (NODC Accession 0112267)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0112267 includes chemical, discrete sample, optical, physical and profile data collected from MIRAI in the Japan Sea, North Pacific Ocean and Sea of...

  9. 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 KEIFU MARU in the East China Sea, Japan Sea and others from 2012-10-24 to 2013-08-27 (NODC Accession 0116977)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0116977 includes Surface underway, chemical, meteorological and physical data collected from KEIFU MARU in the East China Sea (Tung Hai), Japan Sea,...

  10. Testing models of basin inversion in the eastern North Sea using exceptionally accurate thermal and maturity data

    DEFF Research Database (Denmark)

    Nielsen, S.B.; Clausen, O.R.; Gallagher, Kerry

    2011-01-01

    of the wells is the Sorgenfrei-Tornquist Zone (STZ) in the eastern North Sea of (mainly) Carboniferous-Permian origin. Additional minor extension episodes occurred during the Triassic, Jurassic and Cretaceous, mainly centred in the STZ. The STZ experienced strong compressional inversion during the late...... Cretaceous. A thick (c. 1600 m) late Cretaceous and Danian chalk sequence has recorded the associated marginal trough formation. A hiatus of duration c. 60 Myr follows until the deposition of thin Quaternary sediments. The question we address here is if the thermal data from the wells contain information...

  11. Temporal and spatial variations of134Cs and137Cs levels in the Sea of Japan and Pacific coastal region: Implications for dispersion of FDNPP-derived radiocesium.

    Science.gov (United States)

    Inoue, M; Shirotani, Y; Yamashita, S; Takata, H; Kofuji, H; Ambe, D; Honda, N; Yagi, Y; Nagao, S

    2018-02-01

    To investigate the dispersion of Fukushima Dai-ichi Nuclear Power Plant (FDNPP)-derived radiocesium in the Sea of Japan and western Pacific coastal region and determine the sources of radiocesium in these areas, we examined the temporal and spatial variations of 134 Cs and 137 Cs concentrations (activities) during 2011-2016 in seawaters around the western Japanese Archipelago, particularly in the Sea of Japan. In May 2013, the surface concentration of 134 Cs was ∼0.5 mBq/L (decay-corrected to March 11, 2011), and that of 137 Cs exceeded the pre-accident level in this study area, where the effects of radiocesium depositions just after the FDNPP accident disappeared in surface waters in October 2011. Subsequently, radiocesium concentrations gradually increased during 2013-2016 (∼0.5-1 mBq/L for 134 Cs), exhibiting approximately homogeneous distributions in each year. The temporal and spatial variations of 134 Cs and 137 Cs concentrations indicated that FDNPP-derived radiocesium around the western Japanese Archipelago, including the Sea of Japan, has been supported by the Kuroshio Current and its branch, Tsushima Warm Current, during 2013-2016. However, in the Sea of Japan, the penetration of 134 Cs was limited to depths of less than ∼200 m during three years following the re-delivery of FDNPP-derived radiocesium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Ostreopsis fattorussoi sp. nov. (Dinophyceae), a new benthic toxic Ostreopsis species from the eastern Mediterranean Sea.

    Science.gov (United States)

    Accoroni, Stefano; Romagnoli, Tiziana; Penna, Antonella; Capellacci, Samuela; Ciminiello, Patrizia; Dell'Aversano, Carmela; Tartaglione, Luciana; Abboud-Abi Saab, Marie; Giussani, Valentina; Asnaghi, Valentina; Chiantore, Mariachiara; Totti, Cecilia

    2016-12-01

    The new benthic toxic dinoflagellate, Ostreopsis fattorussoi sp. nov., is described from the Eastern Mediterranean Sea, Lebanon and Cyprus coasts, and is supported by morphological and molecular data. The plate formula, Po, 3', 7″, 6c, 7s, 5‴, 2'''', is typical for the Ostreopsis genus. It differs from all other Ostreopsis species in that (i) the curved suture between plates 1' and 3' makes them approximately hexagonal, (ii) the 1' plate lies in the left half of the epitheca and is obliquely orientated leading to a characteristic shape of plate 6″. The round thecal pores are bigger than the other two Mediterranean species (O. cf. ovata and O. cf. siamensis). O. fattorussoi is among the smallest species of the genus (DV: 60.07 ± 5.63 μm, AP: 25.66 ± 2.97 μm, W: 39.81 ± 5.05 μm) along with O. ovata. Phylogenetic analyses based on the LSU and internal transcribed spacer rDNA shows that O. fattorussoi belongs to the Atlantic/Mediterranean Ostreopsis spp. clade separated from the other Ostreopsis species. Ostreopsis fattorussoi produces OVTX-a and structural isomers OVTX-d and -e, O. cf. ovata is the only other species of this genus known to produce these toxins. The Lebanese O. fattorussoi did not produce the new palytoxin-like compounds (ovatoxin-i, ovatoxin-j 1 , ovatoxin-j 2 , and ovatoxin-k) that were previously found in O. fattorussoi from Cyprus. The toxin content was in the range of 0.28-0.94 pg · cell -1 . On the Lebanon coast, O. fattorussoi was recorded throughout the year 2015 (temperature range 18°C-31.5°C), with peaks in June and August. © 2016 Phycological Society of America.

  13. Inter-cohort growth patterns of pharaoh cuttlefish Sepia pharaonis (Sepioidea: Sepiidae) in Eastern Arabian Sea.

    Science.gov (United States)

    Sasikumarl, Geetha; Mohamed, K S; Bhat, U S

    2013-03-01

    Sepia pharaonis is an important commercial species endemic to the tropical Indo-Pacific region. Despite its commercial significance, only few information on natural populations is available. This study was aimed to describe the aspects of size-composition, length-weight relationship, catch rates, seasonal recruitment and inter-cohort growth patterns of S. pharaonis population (Clade C), distributed along the Eastern Arabian Sea (South-West coast of India). For this, the Dorsal Mantle Length (DML) and weight of cuttlefishes was obtained from commercial trawl catches, from April 2002 to October 2006. Data was analyzed by normal length-weight methods such as von Bertalanffy. A total of 12454 cuttlefishes, ranging in length from four to 41cm were analyzed. Size-composition patterns discriminated two pulses in recruitment to the fishery, discernible by a decrease in the monthly mean size of the population. The DMLs of the two seasonal cohorts were subjected to modal-progression analysis using the Bhattacharya's method for the estimation of growth. The estimated parameters Linfinity and K in von Bertalanffy Growth Function (VBGF) were used to model growth curves in length for the cohorts. The first cohort, (post-monsoon cohort) which supports the major fishery, was composed of medium-sized, fast growing individuals, whereas the second cohort (pre-monsoon cohort), comprised of slow growing and large-sized individuals. There were differential growth characteristics between the sexes and the life span was estimated at less than 2.3 years for males and 2.1 years for females. Negative allometric growth in weight (W) with length (L) was observed for males (W=0.33069.L2.5389) and females (W=0.32542.L26057). The females were heavier compared to males at any given mantle length, and the males were found to attain larger ultimate lengths. The major fishing season for cuttlefish was from May to November, when higher monthly catch rates of 1.67-13.02kg/h were observed in comparison

  14. Determination of threshold concentrations of metals in indicator algae of coastal waters in the northwest Sea of Japan

    Science.gov (United States)

    Chernova, E. N.; Kozhenkova, S. I.

    2016-05-01

    Background concentrations of Fe, Mn, Cu, Zn, Pb, Cd, and Ni were calculated for thalli of abundant algae of Fucus, Silvetia, Sargassum, Cystoseira spp. from the northwest Sea of Japan during 1987-2008. As the upper threshold levels of metal background concentrations, the median values plus double medians of absolute deviations from the medians were used (Me + 2MAD). The lower threshold level of the background concentration equal to the physiological need for an element is the median of 15% minimum values in the sampling minus the double median of absolute deviations from the median (Me15-2MAD15). The range of Me15 ± 2MAD15 is considered the natural background range of concentrations.

  15. Propagation of pulse pseudorandom signals from a shelf into shallow water in winter hydrological conditions of the Sea of Japan

    Science.gov (United States)

    Morgunov, Yu. N.; Burenin, A. V.; Besotvetnykh, V. V.; Golov, A. A.

    2017-11-01

    The paper discusses the results of an experiment conducted in the Sea of Japan in March 2016 on an acoustic track 194 km long under winter hydrological conditions. We have studied the most complex case of propagation of pulse pseudorandom signals from the shelf into shallow water during vortex generation on the acoustic track. Analysis of the experimentally obtained pulse characteristics have shown that the maximum first approach of acoustic energy recorded at all points agrees well with the calculation. This testifies to the fact that at a given reception depth, the first to arrive are pulses that have passed in the near-surface sound channel over the shortest distance and at small angles close to zero. We propose a technique for calculating the mean sound velocity on the track from satellite monitoring data on the surface temperature, which makes it possible to rely on the successful application of the results obtained in acoustic ranging and navigation problems.

  16. Epifauna of the Sea of Japan collected via a new epibenthic sledge equipped with camera and environmental sensor systems

    Science.gov (United States)

    Brandt, A.; Elsner, N.; Brenke, N.; Golovan, O.; Malyutina, M. V.; Riehl, T.; Schwabe, E.; Würzberg, L.

    2013-02-01

    Faunistic data from a newly designed camera-epibenthic sledge (C-EBS) are presented. These were collected during the joint Russian-German expedition SoJaBio (Sea of Japan Biodiversity Studies) on board the R.V. Akademik Lavrentyev from four transects (A-D) between 460 and 3660 m depth. In total, 244,531 macro- and megafaunal individuals were sampled with the classes Malacostraca (80,851 individuals), Polychaeta (36,253 ind.) and Ophiuroidea (34,004 ind.) being most abundant. Within the Malacostraca, Peracarida (75,716 ind.) were most abundant and within these, the Isopoda were the dominant taxon (27,931 ind.), followed by Amphipoda (21,403 ind.), Cumacea (13,971 ind.) and Tanaidacea (10,830 ind.). Mysidacea (1581 ind.) were least frequent. Bivalvia, Amphipoda, Cumacea and Mysidacea as well as inbenthic meiofaunal Nematoda occurred in higher numbers at the shallower stations and their numbers decreased with increasing depth. Polychaeta, Isopoda, and Tanaidacea, on the contrary, increased in abundance with increasing depth. Only one isopod species was sampled at abyssal depths in the Sea of Japan but at very high abundance: Eurycope spinifrons Gurjanova, 1933 (Asellota: Munnopsidae). Echinoderms occurred frequently at the shallower slope stations. Ophiuroids were dominating, followed by holothurians, and echinoids and asteroids which occurred in lower numbers and primarily at the shallower stations of transects A and B. Only 2163 individual anthozoans were recorded and these were mostly confined to the lower slope. The technical design of a new C-EBS is described. Next to temperature-insulated epi- and suprabenthic samplers, it is equipped with still and video cameras, which deliver information on seabed topography and megafaunal occurrence. Furthermore, Aanderaa CTD and SEAGUARD RCM allow for collection of physical parameters, such as near bottom oxygen composition, temperature and conductivity.

  17. Dynamic Analysis of Product Lifecycle and Sea/Air Modal Choice: Evidence of Export from Japan1

    Directory of Open Access Journals (Sweden)

    Hideki Murakami

    2014-12-01

    Full Text Available Here, we test the hypothesis that commodities at their peak valuation are transported by air, while those at their inception and maturity are shipped by sea, as well as the theory that shippers choose air to transport high-valued commodities. We empirically investigated how the product lifecycle of commodities is reflected by shippers’ choices of air over seaborne transportation. We also assumed that commodities that achieved substantial innovation in their lifecycles would be moved by air transportation so that these commodities could reach targeted markets as quickly as possible to avoid the opportunity costs that might be generated by missed business chances. We constructed two sets of unbalanced panel data of 14 commodities for 24 years drawn from Japan's customs, demographic, and international statistics. By estimating structural equation systems that consisted of commodity-specific export and export air ratio functions, we found that the product lifecycle of cargo outgoing from Japan exactly matched the upward and downward movement of the air ratio.

  18. Spatial distribution of cold-season lightning frequency in the coastal areas of the Sea of Japan

    Science.gov (United States)

    Tsurushima, Daiki; Sakaida, Kiyotaka; Honma, Noriyasu

    2017-12-01

    The coastal areas of the Sea of Japan are a well-known hotspot of winter lightning activity. This study distinguishes between three common types of winter lightning in that region (types A-C), based on their frequency distributions and the meteorological conditions under which they occur. Type A lightning occurs with high frequency in the Tohoku district. It is mainly caused by cold fronts that accompany cyclones passing north of the Japanese islands. Type B, which occurs most frequently in the coastal areas of the Hokuriku district, is mainly caused by topographically induced wind convergence and convective instability, both of which are associated with cyclones having multiple centers. Type C's lightning frequency distribution pattern is similar to that of type B, but its principal cause is a topographically induced wind convergence generated by cold air advection from the Siberian continent. Type A is most frequently observed from October to November, while types B and C tend to appear from November to January, consistent with seasonal changes in lightning frequency distribution in Japan's Tohoku and Hokuriku districts.

  19. Fate of two important radionuclides in the coastal seas of Japan and resultant dose from intake through fishery products

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Teruhisa; Matsuba, Mitsue; Yokosuka, Setsuko [Laboratory for Radioecology, National Institute of Radiological Sciences, Hitachinaka, Ibaraki (Japan)

    2000-05-01

    The relationship between the inflow of two important radionuclides, namely {sup 90}Sr and {sup 137}Cs, and their concentrations in seawater was investigated by introducing a simplified mathematical model which expressed the course of time of the concentration of radionuclides in seawater in the first order kinetics. The comparison of the fate was made between two radionuclides for three regions in Japan by comparing the respective two parameters, retention time in the sea and the effective mixing depth, which were derived by regression analyses of the radioactivity survey data reported since 1960. Generally speaking, there were not so great differences in the fate in the coastal seas of Japan between two radionuclides, although the effective mixing depth was slightly shallower for {sup 90}Sr than for {sup 137}Cs. The effective retention time was obtained as 7.1, 6.9 and 3.1 years in terms of a half value period for {sup 90}Sr in the coastal sea near the prefectures, Ibaraki, Niigata And Fukui, respectively, whereas 7.2, 6.4 and 8.7 years for {sup 137}Cs in the same order. On the other hand, the respective effective mixing depth which was defined here as the depth within radionuclides were virtually distributed uniformly was 29, 44 and 24 m for {sup 90}Sr, whereas 47, 47 and 85 m for {sup 137}Cs. These results suggested that radionuclides flowing into the surface of the sea in the same mode as the atmospheric fallout principally be associated into the existing dispersion system in the water body dispersed rather independently of species of radionuclide. The contribution of chemical and biological fractionation to the distribution in the sea would be not so critical between {sup 90}Sr and {sup 137}Cs. The radiological impacts in the case of the event of inflow of radionuclides into the sea would be evaluated by determining the dose commitment. The dose commitment would be given as the multiplication of the integrated concentration in seawater, the concentration

  20. Habitat template approach for green roofs using a native rocky sea coast plant community in Japan.

    Science.gov (United States)

    Nagase, Ayako; Tashiro-Ishii, Yurika

    2018-01-15

    The present study examined whether it is possible to simulate a local herbaceous coastal plant community on a roof, by studying the natural habitats of rocky sea coast plants and their propagation and performance on a green roof. After studying the natural habitat of coastal areas in Izu peninsula, a germination and cutting transplant study was carried out using herbaceous plants from the Jogasaki sea coast. Many plant species did not germinate at all and the use of cuttings was a better method than direct seeding. The green roof was installed in the spring of 2012 in Chiba city. Thirteen plant species from the Jogasaki sea coast, which were successfully propagated, were planted in three kinds of substrate (15 cm depth): pumice, roof tile and commercial green roof substrate. The water drainage was restricted and a reservoir with 5 cm depth of water underlaid the substrate to simulate a similar growing environment to the sea coast. Volcanic rocks were placed as mulch to create a landscape similar to that on the Jogasaki sea coast. Plant coverage on the green roof was measured every month from June 2012 to October 2014. All plants were harvested and their dry shoot weight was measured in December 2014. The type of substrate did not cause significant differences in plant survival and dry shoot weight. Sea coast plant species were divided into four categories: vigorous growth; seasonal change; disappearing after a few years; limited growth. Understanding the ecology of natural habitats was important to simulating a local landscape using native plant communities on the green roof. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Absolute sea levels and isostatic changes of the eastern North Sea to central Baltic region during the last 900 years

    DEFF Research Database (Denmark)

    Hansen, Jens Morten; Aagaard, Troels; Binderup, Merete

    2012-01-01

    that ice-cap growth can be faster than ice-cap melting. By comparison with 29 long-term tide gauge measurements of the region we show that the isostatic implications of the sea-level curve are in nearly perfect agreement with Peltier's global isostatic VM2 model (applied by IPCC and PSMSL) and yield a 3...

  2. Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea.

    Directory of Open Access Journals (Sweden)

    Claudio Stalder

    Full Text Available Cold-water coral (CWC ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago. However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents.

  3. Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea.

    Science.gov (United States)

    Stalder, Claudio; Vertino, Agostina; Rosso, Antonietta; Rüggeberg, Andres; Pirkenseer, Claudius; Spangenberg, Jorge E; Spezzaferri, Silvia; Camozzi, Osvaldo; Rappo, Sacha; Hajdas, Irka

    2015-01-01

    Cold-water coral (CWC) ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago). However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata) that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents.

  4. The interaction of prehistoric human settlement, sea level change and tectonic uplift of the Coastal Range, eastern Taiwan

    Science.gov (United States)

    Yang, H.; Chen, W. S.

    2017-12-01

    The late Cenozoic mountain belt of Taiwan, resulting from the collision between the Eurasian and Philippine Sea plates, is known for its rapid tectonic uplift. As postglacial sea level rose ca. 15,000 yr ago, the eastern coast of Taiwan, due to the rapid tectonic uplift rate, displayed a totally different scenario comparing with most of the coastal plains around the world. At the beginning of postglacial era, the sea level rising rate was greater than the tectonic uplift rate which induced the original piedmont alluvial fan or coastal plain to be overwhelmed by sea water rapidly. Around 13.5 ka, the tectonic uplift rate caught up with the sea level rising and broad wave-cut platform formed. The approximation of tectonic uplift and sea level rising rates was lasting from 13.5 to 5ka, but shoreline progradation may have been enhanced by increased slope erosion which resulted in the alluvial fan forming at the later time of this period. As soon as the eustasy stabilized, the landmass continued to uplift which might have enhanced the river incising and wave erosion rapidly. Therefore the topographic expression along the eastern fringing of Coastal Range forms extended alluvial-fan, stream, and marine terraces and are covered by late Holocene colluvium and marine deposits. 88 archaeological sites were chosen in this study based on surface survey where the archaeological chronology of cultural stage is established primarily through examining pottery series and associated manual excavation. It is interesting that most of the archaeological sites were located on the alluvial fan although the Holocene marine terraces have formed after 5ka. There are no clear evidences to support a shore-oriented settlement, but the abundant alluvial depositional structures observed from the overlaying formation reveals the stream depositional system was still active at this time. If the Neolithic people wanted to come to the "new born" coastal region for the abundant ocean resources, they

  5. Strong linkages between surface and deep-water dissolved organic matter in the East/Japan Sea

    Science.gov (United States)

    Kim, Tae-Hoon; Kim, Guebuem; Shen, Yuan; Benner, Ronald

    2017-05-01

    Vertical and horizontal distributions of total dissolved amino acids (TDAAs), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) were measured in the East/Japan Sea (EJS). The euphotic zone of this sea is N-limited, and the N : P ratio is ˜ 13 below 200 m depth. Elevated TDAA concentrations (137 ± 34 nM) and DOC-normalized yields (0.8 ± 0.2 % of DOC) were observed in deep waters ( ≥ 1000 m) of the EJS and compared with those in the deep North Pacific Ocean. Significantly high TDAA concentrations and yields were observed in a region of deep-water formation, indicating the convection of margin-derived bioavailable dissolved organic matter (DOM) to deep waters. Declining TDAA concentrations (36 ± 12 %) and yields (33 ± 13 %) were observed between 1000 and 3000 m throughout the EJS, indicating the utilization of bioavailable DOM in deep waters. Concentrations of the D-enantiomers of amino acids (Ala, Glx, Asx, and Ser) were relatively high in deep waters of the EJS, indicating substantial bacterial contributions to DOM from surface and upper mesopelagic waters. Climate warming during the past few decades in the EJS is weakening deep convection during the winter, and one consequence of this reduction in deep convection is a decline in the supply of bioavailable DOM from surface waters.

  6. Direct ageing of Thunnus thynnus from the eastern Atlantic Ocean and western Mediterranean Sea using dorsal fin spines.

    Science.gov (United States)

    Luque, P L; Rodriguez-Marin, E; Landa, J; Ruiz, M; Quelle, P; Macias, D; Ortiz De Urbina, J M

    2014-06-01

    This study deals with important methodology issues that affect age estimates of eastern Atlantic bluefin tuna Thunnus thynnus using dorsal fin spines. Nearly 3800 spine sections were used from fish caught in the north-east Atlantic Ocean and western Mediterranean Sea over a 21 year period. Edge type and marginal increment analyses indicated a yearly periodicity of annulus formation with the translucent bands (50% of occurrence) appearing from October to May. Nucleus vascularization seriously affected specimens older than 6 years, with the disappearance of 40-50% of the presumed annuli by that age. An alternate sectioning location was a clear improvement and this finding is an important contribution to the methodology of using this structure for ageing the full-length range of eastern T. thynnus. Finally, there were no significant differences between the coefficients of von Bertalanffy growth model estimated from mean length at age data (L∞  = 327.4; k = 0.097; t0  = -0.838) and those estimated from the growth curves accepted for the eastern and western T. thynnus management units. © 2014 The Fisheries Society of the British Isles.

  7. Size, diet, and condition of age-0 Pacific cod (Gadus macrocephalus) during warm and cool climate states in the eastern Bering sea

    Science.gov (United States)

    Farley, Edward V.; Heintz, Ron A.; Andrews, Alex G.; Hurst, Thomas P.

    2016-12-01

    The revised Oscillating Control Hypothesis for the Bering Sea suggests that recruitment of groundfish is linked to climatic processes affecting seasonal sea ice that, in turn, drives the quality and quantity of prey available to young fish for growth and energy storage during their critical life history stages. We test this notion for age-0 (juvenile) Pacific cod (Gadus macrocephalus) by examining the variability in size, diet, and energetic condition during warm (2003-2005), average (2006), and cool (2007-2011) climate states in the eastern Bering Sea. Juvenile cod stomachs contained high proportions of age-0 walleye pollock (by wet weight) during years with warm sea temperatures with a shift to euphausiids and large copepods during years with cool sea temperatures. Juvenile cod were largest during years with warm sea temperatures and smallest during years with cool sea temperatures. However, energetic status (condition) of juvenile cod was highest during years with cool sea temperatures. This result is likely linked to the shift to high quality, lipid-rich prey found in greater abundance on the shelf and in the stomach contents of juvenile cod during cool years. Our examination of juvenile cod size, diet, and energetic status provided results that are similar to those from studies on juvenile pollock, suggesting that the common mechanisms regulating gadid recruitment on the eastern Bering Sea shelf are climate state, prey quality and quantity, and caloric density of gadids prior to winter.

  8. Cetacean distribution and abundance in relation to oceanographic domains on the eastern Bering Sea shelf: 1999-2004

    Science.gov (United States)

    Friday, Nancy A.; Waite, Janice M.; Zerbini, Alexandre N.; Moore, Sue E.

    2012-06-01

    Visual line transect surveys for cetaceans were conducted on the eastern Bering Sea shelf in association with pollock stock assessment surveys aboard the NOAA ship Miller Freeman in June and July of 1999, 2000, 2002, and 2004. Transect survey effort ranged from 1188 km in 1999 to 3761 km in 2002. Fin whales (Balaenoptera physalus) were the most common large whale in all years except 2004 when humpback whales (Megaptera novaeangliae) were more abundant. Dall's porpoise (Phocoenoides dalli) were the most common small cetacean in all years. Abundance estimates were calculated by year for each oceanographic domain: coastal, middle, and outer/slope. The middle and outer/slope domains were divided into two strata ("north" and "south") because of variable survey effort. The distribution and abundance of baleen whales changed between the earlier (colder) and later (warmer) survey years. Fin whales consistently occupied the outer shelf and secondarily the middle shelf, and their abundance was an order of magnitude greater in cold compared to warm years. Humpback whales "lived on the margin" of the northern Alaska Peninsula, eastern Aleutian Islands and Bristol Bay; their preferred habitat is possibly associated with areas of high prey availability due to nutrient upwelling and aggregation mechanisms. Minke whales (Balaenoptera acutorostrata) occur shoreward of fin whales in the outer and middle shelf and in coastal habitats along the Alaska Peninsula. The highest abundance for this species was observed in a cold (1999) year. No clear relationship emerged for odontocetes with regard to warm and cold years. Dall's porpoise occupied both outer and middle domains and harbor porpoise (Phocoena phocoena) were more common in middle and coastal domains. This study provided a unique, broad-scale assessment of cetacean distribution and abundance on the eastern Bering Sea shelf and a baseline for future comparisons.

  9. Ultraphytoplankton basin-scale distribution in the eastern Mediterranean Sea in winter: link to hydrodynamism and nutrients

    Directory of Open Access Journals (Sweden)

    M. Denis

    2010-07-01

    Full Text Available The basin-scale distribution of ultraphytoplankton (<10 μm was determined in the upper 200 m of the eastern Mediterranean Sea during the winter season. Four clusters were resolved by flow cytometry on the basis of their optical properties and identified as Synechococcus, Prochlorococcus, pico- (<3 μm and nanoeukaryotes (3–10 μm. Synechococcus was the most abundant population (maximum abundance of about 37 000 cells cm−3 and contributed up to 67.7% to the overall ultraphytoplanktonic carbon biomass, whereas the contribution of Prochlorococcus never exceeded 6.5%. The maximum integrated carbon biomass was 1763, 453, 58 and 571 mg C m−2 for nanoeukaryotes, picoeukaryotes, Prochlorococcus and Synechococcus respectively. Water mass properties were analyzed on the basis of temperature and salinity distributions in order to account for the general circulation and locate the main hydrodynamic structures (fronts, gyres, transition between western and eastern basins. The effect of the main hydrodynamic structures and nutrients on the ultraphytoplankton distribution was investigated. No positive correlation between nutrients and phytoplankton could be established when considering large scales. However, below 50 m depth, nutrient ratios between particular stations were correlated to corresponding density ratios. In contrast, significant relationships were found between Synechococcus abundance and density, resulting from the impact of a gyre in southern Adriatic basin and a thermohaline front in the Ionian basin. A significant relationship was also found between picoeukaryotes and salinity in the comparison of western and eastern Mediterranean Sea.

  10. Small phytoplankton contribution to the total primary production in the highly productive Ulleung Basin in the East/Japan Sea

    Science.gov (United States)

    Joo, HuiTae; Son, SeungHyun; Park, Jung-Woo; Kang, Jae Joong; Jeong, Jin-Yong; Kwon, Jae-Il; Kang, Chang-Keun; Lee, Sang Heon

    2017-09-01

    The Ulleung Basin in the southwestern East/Japan Sea (hereafter East Sea) is known as a biologically productive ;hot spot; but climate-associated changes in the physicochemical oceanographic conditions and some biological changes have been reported. In this study, our main objective was to determine the contribution of small phytoplankton to the total primary production, which is valuable information for detecting marine ecosystem changes in the Ulleung Basin. The small phytoplankton productivity contributions determined by Moderate-Resolution Imaging Spectroradiometer (MODIS)-derived monthly productivities using a phytoplankton community-based productivity algorithm was significantly consistent with the field-measured productivity contributions of small phytoplankton in this study. The daily primary productivity of small phytoplankton ranged from 42.7 to 418.7 mg C m-2 d-1 with an average of 172.9 mg C m-2 d-1 (S.D. = ±61.4 mg C m-2 d-1, n = 120), and the annual contribution of small phytoplankton ranged from 19.6% to 28.4% with an average of 23.6% (S.D. = ±8.1%) in the Ulleung Basin from 2003 to 2012. Overall, large phytoplankton were a major contributor to the total primary production in the Ulleung Basin (76.4 ± 8.2%) from 2003 to 2012, which indicates that the Ulleung Basin is a highly productive region. A significantly negative relationship (p climate change depending on different-size phytoplankton compositions should be a subject for further investigation in the Ulleung Basin as a biologically highly productive region in the East Sea.

  11. Sea-to-air and diapycnal nitrous oxide fluxes in the eastern tropical North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    A. Kock

    2012-03-01

    Full Text Available Sea-to-air and diapycnal fluxes of nitrous oxide (N2O into the mixed layer were determined during three cruises to the upwelling region off Mauritania. Sea-to-air fluxes as well as diapycnal fluxes were elevated close to the shelf break, but elevated sea-to-air fluxes reached further offshore as a result of the offshore transport of upwelled water masses. To calculate a mixed layer budget for N2O we compared the regionally averaged sea-to-air and diapycnal fluxes and estimated the potential contribution of other processes, such as vertical advection and biological N2O production in the mixed layer. Using common parameterizations for the gas transfer velocity, the comparison of the average sea-to-air and diapycnal N2O fluxes indicated that the mean sea-to-air flux is about three to four times larger than the diapycnal flux. Neither vertical and horizontal advection nor biological production were found sufficient to close the mixed layer budget. Instead, the sea-to-air flux, calculated using a parameterization that takes into account the attenuating effect of surfactants on gas exchange, is in the same range as the diapycnal flux. From our observations we conclude that common parameterizations for the gas transfer velocity likely overestimate the air-sea gas exchange within highly productive upwelling zones.

  12. ENSO signals on sea-surface salinity in the eastern tropical pacific ocean

    Directory of Open Access Journals (Sweden)

    1998-01-01

    types collected in the tropical Pacific are analyzed to assess the regional impacts of past (1972-1996 El Niño Southern Oscillation (ENSO events. Focus is made on the regional changes in sea-surface temperature and salinity. Commercial vessels were recently equipped with automated thermosalinographs which allows to monitor the location of salinity front along the Panama-Tahiti line, separating the Panama Gulf from the South Pacific water masses. The latitudinal change of the salinity front is well correlated with the latitudinal change of the ITCZ. Salinity distribution gives additional information on El-Niño development. How future real time SSS data might provide interesting information on the development of ENSO phenomenon in the eastern tropical Pacific area will be discussed.

  13. Diversity, abundance and niche differentiation of ammonia-oxidizing prokaryotes in mud deposits of the eastern China marginal seas

    Directory of Open Access Journals (Sweden)

    Shaolan eYu

    2016-02-01

    Full Text Available The eastern China marginal seas are prominent examples of river-dominated ocean margins, whose most characteristic feature is the existence of isolated mud patches on sandy sediments. Ammonia-oxidizing prokaryotes play a crucial role in the nitrogen cycles of many marine environments, including marginal seas. However, few studies have attempted to address the distribution patterns of ammonia-oxidizing prokaryotes in mud deposits of these seas. The horizontal and vertical community composition and abundance of ammonia-oxidizing archaea (AOA and bacteria (AOB were investigated in mud deposits of the South Yellow Sea (SYS and the East China Sea (ECS by using amoA clone libraries and quantitative PCR. The diversity of AOB was comparable or higher in the mud zone of SYS and lower in ECS when compared with AOA. Vertically, surface sediments had generally higher diversity of AOA and AOB than middle and bottom layers. Diversity of AOA and AOB showed significant correlation with latitude. Nitrosopumilus and Nitrosospira lineages dominated AOA and AOB communities, respectively. Both AOA and AOB assemblages exhibited greater variations across different sites than those among various depths at one site. The abundance of bacterial amoA was generally higher than that of archaeal amoA, and both of them decreased with depth. Niche differentiation, which was affected by dissolved oxygen, salinity, ammonia and silicate (SiO32-, was observed between AOA and AOB and among different groups of them. The spatial distribution of AOA and AOB was significantly correlated with δ15NTN and SiO32-, and nitrate and δ13C, respectively. Both archaeal and bacterial amoA abundance correlated strongly with SiO32-. This study improves our understanding of spatial distribution of AOA and AOB in ecosystems featuring oceanic mud deposits.

  14. Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

    Directory of Open Access Journals (Sweden)

    V. S. Kumar

    2016-10-01

    Full Text Available We assess the influence of monsoon variability on the surface waves using measured wave data covering 7 years and reanalysis data from 1979 to 2015 during the Indian summer monsoon (JJAS in the eastern Arabian Sea. The inter-annual comparison shows that the percentage of higher wave heights ( >  2.5 m is higher ( ∼  26% in 2014 than in other years due to the higher monsoon wind speed (average speed ∼ 7.3 m s−1 in 2014. Due to the delayed monsoon, monthly average significant wave height (Hm0 of June was lowest (∼ 1.5 m in 2009. The spectral peak shifted to lower frequencies in September due to the reduction of wind seas as a result of decrease in monsoon intensity. The study shows high positive correlation (r ∼ 0.84 between average low-level jet (LLJ for the block 0–15° N, 50–75° E and Hm0 of eastern Arabian Sea in all the months except in August (r ∼ 0.66. The time series data on wave height shows oscillations with periods 5 to 20 days. Wavelet coherence analysis indicates that the LLJ and Hm0 are in-phase related (phase angle 0° almost all the time and LLJ leads Hm0. The monsoon seasonal anomaly of Hm0 is found to have a negative relationship with the Oceanic Niño Index indicating that the monsoon average Hm0 is relatively low during the strong El Niño years.

  15. Euphausiids in the eastern Bering Sea: A synthesis of recent studies of euphausiid production, consumption and population control

    Science.gov (United States)

    Hunt, George L.; Ressler, Patrick H.; Gibson, Georgina A.; De Robertis, Alex; Aydin, Kerim; Sigler, Michael F.; Ortiz, Ivonne; Lessard, Evelyn J.; Williams, Benjamin C.; Pinchuk, Alexei; Buckley, Troy

    2016-12-01

    Euphausiids are an important component of the eastern Bering Sea marine ecosystem. We synthesized information on the ecological roles of two species, Thysanoessa raschii, which predominates over the Middle and Inner Shelf Domains, and Thysanoessa inermis, which predominates over the Outer Shelf Domain. Although estimates of euphausiid biomass across the shelf are not well constrained, we estimated that, between April and July, 2004-2010, euphausiid biomass was 3.08-5.25 g C m-2 on the outer shelf and 1.95-3.92 g C m-2 on the middle shelf. Modeled estimates of euphausiid production, for spring and summer combined, varied between 0.043 g C m-2 d-1 and 0.051 g C m-2 d-1, depending on location, with a mean of 0.048 g C m-2 d-1. Recently reported field measurements of annual primary production over the southeastern Bering Sea in 2008-2009 vary between 0.06 and 6.65 g C m-2 d-1, with a mean of 1.262 g C m-2 d-1±2.049 g C m-2 d-1 in spring and summer combined, a level sufficient to support euphausiids, at least on an annualized basis. Walleye pollock (Gadus chalcogrammus, hereafter pollock) is the single most important consumer of euphausiids over the eastern Bering Sea shelf. We estimated that pollock consumed between 0.0042 and 0.019.7 g C m-2 d-1 of euphausiids, depending on year, with a mean of 0.011 g C m-2 d-1 in summer averaged over 1999-2009. This consumption is equivalent to between 17% and 29% of summer euphausiid production, depending on location. Over the period for which data were available (2004-2012), we observed a strong negative relationship between euphausiid biomass as determined in acoustic surveys and pollock biomass as estimated in the eastern Bering Sea pollock stock assessment (r2=0.82). During this time period, sea-surface temperature was the second strongest predictor of euphausiid biomass, (r2=0.63). However, for the period 2004-2010, bottom temperature (r2=0.94) was the strongest predictor, followed by pollock biomass from the pollock stock

  16. Qualitative and quantitative composition of microplastics particles during the expeditionary measurement program in the South-Eastern Baltic Sea

    Science.gov (United States)

    Esiukova, Elena; Bagaeva, Margarita; Chubarenko, Natalia

    2016-04-01

    According to the tasks of the Russian Science Foundation project "Physical and dynamical properties of marine microplastics particles and their transport in a basin with vertical and horizontal salinity gradient on the example of the Baltic Sea" number 15-17-10020, a comprehensive expeditionary program of measurements in the South-Eastern Baltic started. The project is aimed at finding solutions for a number of problems caused by superfluous plastic pollution in the World Ocean and, in particular, in the Baltic Sea. This pollution has been accumulating for years and just recently it has become obvious that only multidisciplinary approach (geographical, biological, chemical, etc.) to the issues related to the processes of transformation of properties and propagation of plastic particles will allow the study of physical aspects of the problem. During the first stage of the study samples should be selected from the water surface, water column at various horizons, bottom sediments in the Baltic Sea, from different areas at the beaches - in order to further examine the qualitative and quantitative composition of microplastic particles in different seasons for different hydrophysical situations. Reconnaissance survey was begun to choose the fields for research close to point and distributed sources of microplastics. Preference is given to those beaches that are exposed to maximum anthropogenic pollution: areas around the town of Baltiysk, the northern part of the Vistula Spit (near the settlement of Kosa), and the Sambia peninsula coast (settlements of Yantarny, Donskoye, Primorye, Kulikovo, towns of Svetlogorsk, Pionersky, Zelenogradsk). Locations for experimental sites were found in order to assess time for formation of microplastics (Vistula Spit, Kosa settlement). In June-November, 2015 there were 5 expeditions in the waters of the South-Eastern Baltic, 7 expeditions along the coast line of the Baltic Sea (in Kaliningrad Oblast), and 5 expeditions to the Vistula

  17. The fate of {sup 137}Cs in the coastal seas of Japan and the resultant dose from intake through fishery products

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Teruhisa; Matsuba, Mitsue; Yokosuka, Setsuko [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Nakaminato Lab. Branch

    1998-06-01

    The relationship between the flux of the atmospheric {sup 137}Cs at the surface of the seas and its concentration in seawater was studied to elucidate its fate in the marine environment and to assess the radiological effects on the human population. In this context, a simplified mathematical model that expressed the time course of the concentration in the first order of kinetics was introduced, and the parameters involved in the formula were numerically derived for three regions of the coastal sea of Japan by a regression analysis from a series of radioactivity survey data reported over the past 30 years since 1960. It is expected that {sup 137}Cs was retained in the coastal sea of Japan with a half-life period ranging from 5.3 to 6.8 years without a great difference between the Pacific Ocean and the Sea of Japan. The integrated concentrations of {sup 137}Cs in seawater were determined as 0.191, 0.173, and 0.120 mBq{center_dot}a/l, respectively, for the coasts of Ibaraki/Fukushima, Niigata, and Fukui prefectures as a result of the deposition at a unit density (1 MBq/km{sup 2}). The resultant dose commitment to the respective populations would amount to 4.5, 2.4, and 0.9 x 10{sup -3} man{center_dot}Sv through coastal fishery products. (author)

  18. The prospects of nuclear power development in the eastern part of the Baltic Sea region as a factor of the formation of international relations system in the region

    OpenAIRE

    Mezhevich, Nikolai M.

    2013-01-01

    The current development of economic diplomacy in the world is determined by a combination of globalization and regionalization. In addition, it has an economic dimension. At the same time, the Baltic Sea region demonstrates large-scale politicisation of economic cooperation. The development of nuclear power in the eastern part of the Baltic Sea is indicative of the effectiveness of political and economic cooperation in the region. The author believes that Russia and the three Baltic States of...

  19. Comparative Morphometric Analysis of the Smallscaled Scorpionfish, Scorpaena Porcus (Scorpaenidae, Scorpaeniformes, from the Southern Coast of the Crimea and Eastern Part of the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Manilo L. G.

    2016-12-01

    Full Text Available Comparative analysis of morphometric characters of small-scaled scorpionfish from the Black Sea (near the southern coast of the Crimea and from the eastern part of the Adriatic Sea showed significant differences in males and females on thirteen plastic and three meristic characters. These differences may be due to unequal abiotic and biotic habitat conditions, and refer about the geographical variability of the species, indicating the presence of two different populations in the study area.

  20. Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; George, M.D.; Rajendran, A.

    Extensive observations have been made on the carbon dioxide system in the Arabian Sea during three different seasons as part of the Indian Joint Global Ocean Flux Study (JGOFS) Programme. Concentrations of total carbon dioxide and partial pressure...

  1. AFSC/RACE/GAP/Yeung: Eastern Bering Sea Essential Fish Habitat Benthic Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic samples were collected between 2009-2012 in the Bering Sea to study Essential Fish Habitat. Station locations were at or near fixed stations of the AFSC...

  2. Analysis of multi-scale morphodynamic behaviour of a high energy beach facing the Sea of Japan

    Directory of Open Access Journals (Sweden)

    Harshinie Urmila Karunarathna

    2015-07-01

    Full Text Available Monthly cross shore beach profiles measured at the Ogata Wave Observation pier located in Joetsu-Ogata Coast, Niigata Prefecture, Japan, was analysed to investigate multi-scale morphodynamic beach behaviour. The Ogata beach, facing the Sea of Japan, is subjected to high energy wave conditions with that has a strong winter/summer seasonal signature. The measured beach profiles at the beach show very significant variability where cross-shore movement of shoreline position and lowering of the beach at the location of measurements exceed 20 m and 4 m respectively. The shoreline position seems to follow the seasonal variability of incident wave climate where a correlation coefficient of 0.77 was found between monthly averaged incident significant wave height and the measured monthly shoreline position. During the summer months, the beach variability mostly concentrated to in the sub-tidal part of the profile, while a significant amount of upper beach change was observed during the winter months. The beach profile shape was found to rotate between three different beach states in time; (i concave reflective profile; (ii profile with sub-tidal berm; and (iii gentle, dissipative profile. Empirical Orthogonal Function (EOF analysis of the profiles show that the variability of beach profile shape is dominated by (a upper shoreface steepening; (b sub tidal berm development and dissipation; and (c variability of the overall profile slope, which have some longer than seasonal cyclic signatures. Comparison of temporal EOFs with climate indices such as Southern Oscillation Index and Pacific Decadal Oscillation index shows notable some correlations between profile change and climatic variability in the region. The analysis also shows that the morphological variability of Joetsu-Ogata Coast has similarities and some distinct spatial and temporal differences to beaches of similar kind found elsewhere.

  3. Mud Volcanism and Fluid Venting In The Eastern Mediterranean Sea: Observations From Sidescan Sonar and Submersible Surveys

    Science.gov (United States)

    Zitter, T. A. C.; Huguen, C.; Woodside, J. M.; Mascle, J.; Scientific Party, Medineth/Medinaut

    Mud volcanoes in the eastern Mediterranean Sea have been identified by their distinctive acoustic signature as well as their morphology and sedimentology. They appear as circular regions of high backscatter believed to be caused principally by the clast content of the mud flows forming the mud volcano. Both the MEDINAUT and MEDINETH expeditions, conducted in 1998 and 1999 over two mud fields, the Olimpi field and the Anaximander Mountains area, in Eastern Mediterranean Sea, studied mud volcanism using a multidisciplinary approach in order to determine the relationships between the activity of the mud volcanoes (importance of degassing, associated fauna) and their geophysical signature. Mud volcanoes in Eastern Mediterranean Sea vary from conical and dome-shaped reliefs from 500m to 2km wide and 100 to 200m high to large "mud pie" types up to 6km wide. Sidescan sonar records give a very high resolution of the acoustic response, enabling to distinguish several mud flows, often flowing along tectonic lineations. A clear relationship between the occurrence of mud volcanism and cold seeps and both thrust and transcurrent faulting has been observed in both mud fields, although the tectonic settings vary from purely compressional to a more transpressional stress field. The faults are inferred to provide pathways for over- pressured fluids, and secondary faulting (transcurrent and extensional faults) may facilitate mud ascension. On the basis of sidescan sonar interpretation, other typical features have been inferred such as main feeder channels, eruptive cone centers, or brine pools. The in situ observations have been used to characterize the seafloor over numerous mud volcanoes and ground-truth the sonar data. They reveal an abundance of fluid seeps, mainly methane and methane-rich brines, as well as associated specific fauna such as tube worms, clams and chemosynthetic bacteria, and specific diagenetic phenomenon i.e. carbonate crusts. Video observations proved that

  4. Trace-metal distributions in seawater and anoxic brines in the eastern Mediterranean Sea

    NARCIS (Netherlands)

    Saager, Paul M.; Schijf, Johan; Baar, Hein J.W. de; Millero, F.J.

    1993-01-01

    The vertical distribution of dissolved and particulate trace metals (Mn, Fe, Ni, Cu, Cd) is reported for seawater and the anoxic brines of Tyro and Bannock Basins in the eastern Mediterranean. In normal Mediterranean seawater, the distribution of dissolved trace metals is governed by water mass

  5. Mud volcanoes and gas hydrates in the Anaximander mountains (Eastern Mediterranean Sea)

    NARCIS (Netherlands)

    Lykousis, V.; Alexandri, S.; Woodside, J.M.; de Lange, G.; Dahlmann, A.; Perissoratis, C.; Heeschen, K.; Ioakim, Chr.; Sakellariou, D.; Nomikou, P.; Rousakis, G.; Casas, D.; Ballas, D.; Ercilla, G.

    2009-01-01

    Detailed multibeam, sedimentological, and geophysical surveys provide ample new data to confirm that the Anaximander Mountains (Eastern Mediterranean) are an important area for active mud volcanism and gas hydrate formation. More than 3000 km of multibeam track length was acquired during two recent

  6. Sequence stratigraphy and a revised sea-level curve for the Middle Devonian of eastern North America

    Science.gov (United States)

    Brett, Carlton E.; Baird, G.C.; Bartholomew, A.J.; DeSantis, M.K.; Ver Straeten, C.A.

    2011-01-01

    The well-exposed Middle Devonian rocks of the Appalachian foreland basin (Onondaga Formation; Hamilton Group, Tully Formation, and the Genesee Group of New York State) preserve one of the most detailed records of high-order sea-level oscillation cycles for this time period in the world. Detailed examination of coeval units in distal areas of the Appalachian Basin, as well as portions of the Michigan and Illinois basins, has revealed that the pattern of high-order sea-level oscillations documented in the New York-Pennsylvania section can be positively identified in all areas of eastern North America where coeval units are preserved. The persistence of the pattern of high-order sea-level cycles across such a wide geographic area suggests that these cycles are allocyclic in nature with primary control on deposition being eustatic sea-level oscillation, as opposed to autocylic controls, such as sediment supply, which would be more local in their manifestation. There is strong evidence from studies of cyclicity and spectral analysis that these cycles are also related to Milankovitch orbital variations, with the short and long-term eccentricity cycles (100. kyr and 405. kyr) being the dominant oscillations in many settings. Relative sea-level oscillations of tens of meters are likely and raise considerable issues about the driving mechanism, given that the Middle Devonian appears to record a greenhouse phase of Phanerozoic history. These new correlations lend strong support to a revised high-resolution sea-level oscillation curve for the Middle Devonian for the eastern portion of North America. Recognized third-order sequences are: Eif-1 lower Onondaga Formation, Eif-2: upper Onondaga and Union Springs formations; Eif-Giv: Oatka Creek Formation; Giv-1: Skaneateles, Giv-2: Ludlowville, Giv-3: lower Moscow, Giv-4: upper Moscow-lower Tully, and Giv-5: middle Tully-Geneseo formations. Thus, in contrast with the widely cited eustatic curve of Johnson et al. (1985), which

  7. Squamamoeba japonica n. g. n. sp. (Amoebozoa): a deep-sea amoeba from the Sea of Japan with a novel cell coat structure.

    Science.gov (United States)

    Kudryavtsev, Alexander; Pawlowski, Jan

    2013-01-01

    Squamamoeba japonica n. g. n. sp. was isolated and described from marine bottom sediments collected at a depth of ca. 2700 m in the Sea of Japan. Trophic amoebae of this species are elongated and flattened, with a wide anterior hyaloplasm producing numerous ventral subpseudopodia for adhesion to the substratum. The cell coat consists of flat oval scales tightly packed together to form a continuous layer separated from the plasma membrane. Amoebae can form cytoplasmic projections protruding through the scale layer and having tips covered only with the plasma membrane. Small subunit ribosomal RNA gene phylogeny shows that S. japonica forms a long branch in the amoebozoan tree, robustly grouping with the marine strain 'Pessonella' sp. PRA-29. Morphological data available for the latter, although scarce, give additional support for the relatedness of both species. The resulting clade comprising the two taxa shows no close relationships to other Amoebozoa and seems to be a novel lineage that developed an ability to temporarily liberate local areas of the plasma membrane from the cell coat independently from Himatismenida, Trichosida, Pellitida and Dermamoeba. Copyright © 2012 Elsevier GmbH. All rights reserved.

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

    Science.gov (United States)

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

    2017-10-01

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

  9. Studies on the pore water sulfate, chloride and sedimentary methane to understand the sulfate reduction process in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Borole, D.V.; Rao, B.R.; Paropkari, A.L.; Joao, H.M.; Kocherla, M.; Sarkar, G.P.; Biswas, G.; Kumar, N.

    Sediment cores (~5 m length) from ten stations collected in the water depths of 2665-3210 m in the eastern Arabian Sea were studied for pore water sulfate (SO42-), chloride (Cl-) and lighter-hydrocarbons (methane: C1, ethane:C2 and propane: C3...

  10. Temporal variations in the wind and wave climate at a location in the eastern Arabian Sea based on ERA-Interim reanalysis data.

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.

    Temporal variations in wind speed and significant wave height (SWH) at a location in the eastern Arabian Sea are studied using ERA-Interim reanalysis data from 1979 to 2012. A shallow water location is selected for the study since measured buoy data...

  11. New distribution records of the gall crab Opecarcinus cathyae van der Meij, 2014 (Decapoda: Brachyura: Cryptochiridae) from the Red Sea, Maldives and Japan

    KAUST Repository

    Meij, Sancia E. T.

    2016-11-12

    The gall crab Opecarcinus cathyae van der Meij, 2014 has been reported from various localities in Indonesia and Malaysia. Recent surveys in the Red Sea, Maldives and Japan yielded additional specimens of O. cathyae, considerably expanding the known distribution range of this species to the east and west. The identity of O. cathyae was confirmed based on COI sequence data, revealing identical haplotypes for the Red Sea, Maldivian and Japanese material and three haplotypes in the Indonesian material. Opecarcinus cathyae has one of the widest known recorded distribution ranges for all gall crab species.

  12. Eukaryotic diversity in late Pleistocene marine sediments around a shallow methane hydrate deposit in the Japan Sea.

    Science.gov (United States)

    Kouduka, M; Tanabe, A S; Yamamoto, S; Yanagawa, K; Nakamura, Y; Akiba, F; Tomaru, H; Toju, H; Suzuki, Y

    2017-09-01

    Marine sediments contain eukaryotic DNA deposited from overlying water columns. However, a large proportion of deposited eukaryotic DNA is aerobically biodegraded in shallow marine sediments. Cold seep sediments are often anaerobic near the sediment-water interface, so eukaryotic DNA in such sediments is expected to be preserved. We investigated deeply buried marine sediments in the Japan Sea, where a methane hydrate deposit is associated with cold seeps. Quantitative PCR analysis revealed the reproducible recovery of eukaryotic DNA in marine sediments at depths up to 31.0 m in the vicinity of the methane hydrate deposit. In contrast, the reproducible recovery of eukaryotic DNA was limited to a shallow depth (8.3 m) in marine sediments not adjacent to the methane hydrate deposit in the same area. Pyrosequencing of an 18S rRNA gene variable region generated 1,276-3,307 reads per sample, which was sufficient to cover the biodiversity based on rarefaction curves. Phylogenetic analysis revealed that most of the eukaryotic DNA originated from radiolarian genera of the class Chaunacanthida, which have SrSO 4 skeletons, the sea grass genus Zostera, and the seaweed genus Sargassum. Eukaryotic DNA originating from other planktonic fauna and land plants was also detected. Diatom sequences closely related to Thalassiosira spp., indicative of cold climates, were obtained from sediments deposited during the last glacial period (MIS-2). Plant sequences of the genera Alnus, Micromonas, and Ulmus were found in sediments deposited during the warm interstadial period (MIS-3). These results suggest the long-term persistence of eukaryotic DNA from terrestrial and aquatic sources in marine sediments associated with cold seeps, and that the genetic information from eukaryotic DNA from deeply buried marine sediments associated with cold seeps can be used to reconstruct environments and ecosystems from the past. © 2017 John Wiley & Sons Ltd.

  13. The Amino Acid Composition of Blue Swimming Crab (Portunus Segnis, Forskal, 1775 from The North Eastern Mediterranean Sea of Turkey

    Directory of Open Access Journals (Sweden)

    Engin Artar

    2018-04-01

    Full Text Available This study was carried out to detect the content of amino acid in female and male specimens of blue swimming crab (Portunus segnis obtained from (including 12 male crab and also 12 female crab North Eastern Mediterranean Sea, Turkey. The protein was identified as 17.63% and 18.13% for female and male crab respevtively. Totally 9 essential amino acids were recorded in the present study. Lysine and leucine constituted the highest essential amino acid (EAA concentrations in P. segnis. This species was found to be in good score in terms of the level of EAA and the EAA/Non-EAA ratios when compared with other economical crab species.

  14. Cryptophyte bloom in a Mediterranean estuary: High abundance of Plagioselmis cf. prolonga in the Krka River estuary (eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Luka Šupraha

    2014-09-01

    Full Text Available During the June 2010 survey of phytoplankton and physicochemical parameters in the Krka River estuary (eastern Adriatic Sea, a cryptophyte bloom was observed. High abundance of cryptophytes (maximum 7.9×106 cells l–1 and high concentrations of the class-specific biomarker pigment alloxanthine (maximum 2312 ng l–1 were detected in the surface layer and at the halocline in the lower reach of the estuary. Taxonomical analysis revealed that the blooming species was Plagioselmis cf. prolonga. Analysis of the environmental parameters in the estuary suggested that the bloom was supported by the slower river flow as well as the increased orthophosphate and ammonium concentrations. The first record of a cryptophyte bloom in the Krka River estuary may indicate that large-scale changes are taking place in the phytoplankton community. Such changes could have a major impact on the natural ecosystem dynamics and the mariculture production in the area.

  15. Cloud amount/frequency, NITRATE and other data from RYOFU MARU in the Sea of Japan from 1979-06-02 to 1979-07-21 (NODC Accession 9100223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Serial data in this accession was collected in Sea of Japan using ship RYOFU MARU. The data was collected between June 2, 1979 and July 21, 1979 and...

  16. Inverted echo sounder measurements collected in the Japan/East Sea, between 1999-06 to July 2001, under the sponsorship of the Office of Naval Research (NODC Accession 0002331)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations were conducted from June 1999 to July 2001 to study the shallow and deep current variability in the southwest Japan/East Sea. Data were collected during...

  17. Pressure/temperature/salinity profiler measurements collected in the Sea of Japan, 2001-06 to July 2001, under the sponsorship of the Office of Naval Research (NODC Accession 0002416)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure/temperature/salinty profiles collected in support of a study to investigate the shallow and deep current variability in the southwest Japan/East Sea....

  18. Surveillance and characterization of avian influenza viruses from migratory water birds in eastern Hokkaido, the northern part of Japan, 2009-2010.

    Science.gov (United States)

    Abao, Lary N B; Jamsransuren, Dulamjav; Bui, Vuong N; Ngo, Lai H; Trinh, Dai Q; Yamaguchi, Emi; Vijaykrishna, Dhanasekaran; Runstadler, Jonathan; Ogawa, Haruko; Imai, Kunitoshi

    2013-04-01

    Avian influenza virus (AIV) surveillance was conducted around a small pond in Obihiro, eastern Hokkaido, Japan. Eleven AIVs were isolated from a total of 1,269 fecal samples of migratory wild birds collected during 2009 and 2010. The sample number covered approximately 60 % of the total number of birds observed during sampling periods. The subtypes of the isolates included H3N8 (4 isolates), H5N2 (3), H6N2 (2), H6N1 (1), and H11N2 (1). The H3N8 subtype was most prevalent as in the previous studies performed in Hokkaido. The three H5N2 isolates genetically characterized as low pathogenic AIV were closely related to the strains previously isolated from aquatic wild birds in Japan and also to the Korean strains isolated from aquatic birds in recent years. In Korea, H5N2 subtype virus has often been isolated from poultry and wild birds, as well as reassortant viruses generated from duck H5N2 viruses and chicken H9N2 virus, and avian-swine-like reassortant H5N2 viruses. Considering the previous chicken outbreaks caused by highly pathogenic H5N2 viruses, which affected many countries, it should be an important priority to continue, monitoring the evolution of H5N2 viruses circulating in the region.

  19. A GIS Approach for Reconstructing the Litorina Sea Lagoon in Tolkuse-Rannametsa Area, Eastern Gulf of Riga.

    Science.gov (United States)

    Habicht, Hando-Laur; Rosentau, Alar; Jõeleht, Argo; Hang, Tiit; Kohv, Marko

    2015-04-01

    The eastern coast of the Gulf of Riga in the NE Baltic Sea is characterized by slow post-glacial isostatic uplift (about 1mm/yr) and slowly undulating low topography. Therefore even small increases in sea-level can easily lead to the flooding of considerable areas. The complex deglaciation history of the Baltic Sea area left, at times, south western Estonia submerged, while at other times, it emerged as terrestrial land. Different transgressive and regressive development stages of the Baltic Sea did not only shape the landscape, but also influenced the locations of the Stone Age settlements which were closely bound to the coastal areas which also include estuaries and lagoonal systems. The coastal region of the Gulf of Riga is abundant in Meso- and Neolithic settlement sites. The present study combines LiDAR, ground-penetrating radar (GPR) and geological data to reconstruct development of the Litorina Sea lagoon in Tolkuse-Rannametsa area and to create prognostic palaeogeographic maps in order to search for Meso- and Neolithic coastal settlement sites. Over 47 km of GPR profiling was done; sediments were described and dated in 37 cores two riverbank outcrops. Diatoms were analysed in the master core. A semi-automatic method for the removal of modern anthropogenic features from LiDAR derived digital elevation model (DEM) was developed, tested and used. In modelling process the impact of sedimentary processes subsequent to the time being modelled was taken into account by employing a backstripping methodology. The differential glacio-isostatic uplift within the study area was taken into account by using interpolated water-level surfaces. Palaeogeographic reconstructions shed new light into region's post-glacial coastal evolution and enabled us to suggest the possible locations of the Stone Age settlements with some of the proposed areas buried under up to 3 m thick peat layer. The results of the current study provide new chronological and shore displacement data

  20. Detecting metastable olivine wedge beneath Japan Sea with deep earthquake coda wave interferometry

    Science.gov (United States)

    Shen, Z.; Zhan, Z.

    2017-12-01

    It has been hypothesized for decades that the lower-pressure olivine phase would kinetically persist in the interior of slab into the transition zone, forming a low-velocity "Metastable Olivine Wedge" (MOW). MOW, if exists, would play a critical role in generating deep earthquakes and parachuting subducted slabs with its buoyancy. However, seismic evidences for MOW are still controversial, and it is suggested that MOW can only be detected using broadband waveforms given the wavefront healing effects for travel times. On the other hand, broadband waveforms are often complicated by shallow heterogeneities. Here we propose a new method using the source-side interferometry of deep earthquake coda to detect MOW. In this method, deep earthquakes are turned into virtual sensors with the reciprocity theorem, and the transient strain from one earthquake to the other is estimated by cross-correlating the coda from the deep earthquake pair at the same stations. This approach effectively isolates near-source structure from complicated shallow structures, hence provide finer resolution to deep slab structures. We apply this method to Japan subduction zone with Hi-Net data, and our preliminary result does not support a large MOW model (100km thick at 410km) as suggested by several previous studies. Metastable olivine at small scales or distributed in an incoherent manner in deep slabs may still be possible.

  1. Eastern Ionian Sea paleoceanographic conditions during the Plio - Pleistocene as revealed through the study of fish otoliths

    Science.gov (United States)

    Agiadi, K.; Triantaphyllou, M. V.; Girone, A.; Karakitsios, V.; Dermitzakis, M. D.

    2009-04-01

    Fish otoliths from the SE Zakynthos and SW Kephallonia islands (Eastern Ionian Sea) provide new evidence for the reconstruction of the paleoceanographic conditions during the Late Pliocene - Early Pleistocene interval. The forty - six fish taxa identified in the sediments of the study areas are separated in tropical, subtropical, temperate and subpolar ecological groups occupying surface, intermediate and deep water layers, based on their modern geographic and bathymetric distributions. During the Late Pliocene, the presence of Chlorophthalmus agassizi in the Eastern Ionian Sea probably denotes temperate oligotrophic conditions. At about 1.96 Ma B.P the high contribution of the bathypelagic Electrona risso, whose modern contribution is limited by the 10-15° C isotherms and productivity greater than 50gC/m2y (Whitehead et al., 1984), is combined with the increased presence of the deeper water species Maurolicus muelleri and Benthosema glaciale, which are mostly known from the high temperate - subpolar zones of today's oceans (Whitehead et al., 1984; Mytilineou et al., 2005). The nutrient-rich intermediate water layers at this time thus overlie colder deep waters, much like today (Malanotte-Rizzoli et al., 1997). In addition, the high abundance of representatives of the genus Diaphus could imply warmer surface conditions (Whitehead et al., 1984). The situation around 1.93 Ma, throughout the water column, is much more homogenous, signified by the introduction of Hygophum hygomii in the deeper water layers, as well as the decrease in relative abundance of Benthosema glaciale, perhaps due to a certain increase in deep water temperate. However, the most dominant species by far in the assemblage remains Ceratoscopelus maderensis, a purely temperate meso-bahtypelagic species (D'Onghia et al., 2004). At around 1.9Ma, there is a marked increase in the relative abundance of tropical taxa, namely Diaphus taaningi and Bregmaceros sp., which occupy the upper 500 meters of the

  2. Isolated intermediate-depth seismicity north of the Izu peninsula, Japan: implications for subduction of the Philippine Sea Plate

    Science.gov (United States)

    Nakajima, Junichi

    2018-01-01

    The subduction of the Philippine Sea (PHS) Plate toward the north of Izu peninsula, Japan, is of great interest because intraslab seismicity is absent where the buoyant Izu volcanic arc has been subducting over the past 15 Myr. This study analyzes 42 earthquakes in an isolated seismic cluster that occurred 100 km north of Izu peninsula at depths of 40-90 km and discusses seismogenesis in the context of plate subduction. We picked P- and S-wave arrival times of earthquakes to produce a complete hypocenter catalogue, carried out double-difference event relocations, and then determined focal mechanism solutions of 7 earthquakes from P-wave polarity data. Based on the focal mechanism solution, the largest earthquake (M3.1) is interpreted as a thrust earthquake along the upper surface of the PHS Plate. Locations of other earthquakes relative to the largest event suggest that most earthquakes occur within the subducting PHS Plate. Our results suggest that the PHS Plate north of Izu peninsula has temperatures low enough to facilitate thrust and intraslab earthquakes at depths of 60-90 km. Earthquakes are likely to occur where pore pressures are locally high, which weakens pre-existing faults. The presence of the intermediate-depth seismic cluster indicates the continuous subduction of the PHS Plate toward the north of Izu peninsula without any disruption.[Figure not available: see fulltext.

  3. Orbital time scale records of Asian eolian dust from the Sea of Japan since the early Pliocene

    Science.gov (United States)

    Zhang, Wenfang; De Vleeschouwer, David; Shen, Ji; Zhang, Zeke; Zeng, Lin

    2018-05-01

    A high-resolution potassium content record of sediments from Integrated Ocean Drilling Program (IODP) Site U1422 drilled in the northern Sea of Japan was employed to yield an astronomical timescale for this ∼205 m thick sedimentary archive. The K content was quantified using the natural gamma radiation (NGR) data routinely measured on DV JOIDES Resolution. The U1422 K (wt.%) series shows an increasing trend with time, which parallels the growth of North Hemisphere ice sheets since ∼4 Ma, as revealed by the global benthic foraminifer's oxygen isotope stack (LR04). We propose that K content variations reflect changes in the relative contributions of Asian eolian dust and volcanic weathering products, in response to changes in global ice volume. Using the shipboard age model, constrained by palaeomagnetism and nanofossils datums, we tuned the U1422 K content variations to the LR04 stack. Our tuned age model for site U1422 goes back to 3.9 Ma. The studied record indicates that Asian dust generation is enhanced during periods of global cooling. The synchronous variations between the U1422 K record and the LR04 stack also suggest that global cooling played a dominant role in promoting the central Asian aridification since ∼3.9 Ma, while the uplift of Tibetan Plateau plays a secondary role, considering many disagreements still exists between the timing and amplitude of the Qinghai-Tibetan uplift and the evolution of central Asian aridity since the early Pliocene.

  4. The Late-Pleistocene sedimentation history in the Eastern Arabian Sea: Climate Weathering-Productivity linkage

    Digital Repository Service at National Institute of Oceanography (India)

    Chodankar, A.R.

    land of Arabia. Where as, until recently other parts of the Arabian Sea were rather ignored. One of such areas is the EAS bordering the west coast of India. Hence, the present work aims to explore the responses of the highly dynamic EAS to the past...), and the details of the mechanism governing the low-salinity tongue are discussed in Chapter 6.1. The biogeochemical responses of the Arabian Sea in general and western region in particular to the past climate and their linkage with monsoon variations have been...

  5. Trace metal concentrations in zooplankton from the eastern Arabian Sea and western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rejomon, G.; Balachandran, K.K.; Nair, M.; Joseph, T.; DineshKumar, P.K.; Achuthankutty, C.T.; Nair, K.K.C.; Pillai, N.G.K.

    continental shelf of 0.5 million km 2 and an exclu- sive economic zone of 2.02 million km 2 . The coastal zone of the country with its wetlands, lagoons, mangroves, sea-grass beds, coral reefs, and shallow bays, creeks, and estuaries is rich in natural sources... program, trace metal distribution in surface seawater and zooplankton of the Bay of Bengal was studied in the Indian exclusive economic zone of the Arabian Sea and Bay of Bengal. The investigation in the Bay of Bengal (Cruise No. 209, November 2002...

  6. Indian Moorings: Deep-sea current meter moorings in the Eastern Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Sarma, M.S.S.; Suryanarayana, A.; Sengupta, D.; Unnikrishnan, A.S.; Fernando, V.; Almeida, A.; Khalap, S.; Sardar, A.; Somasundar, K.; Ravichandran, M.

    at the 93°E mooring location. The time-series currents data are available from the NIO website (http://www.nio.org/data_info/deep-sea_mooring/oos- deep-sea-currentmeter-moorings.htm) and are submitted to the Indian National Center for Ocean Information... System (INCOIS), Hyderabad for display at INCOIS website. The moorings will be recovered in August – September 2006 and will be redeployed at the same locations for another year. Table 1 shows the status of the current data available as of July 2006...

  7. Assessment of metal concentrations (Cu, Zn, and Pb) in seawater, sediment and biota samples in the coastal area of Eastern Black Sea, Turkey.

    Science.gov (United States)

    Baltas, Hasan; Sirin, Murat; Dalgic, Goktug; Bayrak, Esra Yilmaz; Akdeniz, Aysel

    2017-09-15

    This study investigated the contents of Cu, Zn and Pb in seawater, sediment, different shell sizes of mussel (Mytilus galloprovincialis) and sea snail (Rapana venosa) samples collected from four different provinces of the Eastern Black Sea Region. With the exception of Zn, all the metal concentration values measured in the sea snail were observed to be higher than those of mussels in all stations. While the correlation between mussels and sea snail according to metal concentrations was found to be positive (p˂0.05), this relation was not observed between the other parameters, such as the shell sizes, salinity and pH (p˃0.05). Although the mean concentration values of Cu, Zn, and Pb for mussel and sea snail are significantly above the tolerable levels, the estimated daily intake values for mussel were below the daily intake recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Data from investigation on seismic Sea-waves events in the Eastern Mediterranean from the Birth of Christ to 500 A.D.

    Directory of Open Access Journals (Sweden)

    J. ANTONOPOULOS

    1980-06-01

    Full Text Available The Eastern Mediterranean has a long history of damaging seismic sea
    waves (Tsunamis but a great number of them which are locally generated are small. They have caused no serious damage to the coasts because their
    energy is confined by many islands of the Greek Archipelagos. However,
    some of them have been rather severe and destructive to property and
    human life.
    This paper is comprised of data from an investigation into the activity
    of seismic sea waves in the Eastern Mediterranean from the Birth of
    Christ to 500 A.D. It contains a great amount of information concerning
    earthquakes, volcanic eruptions and seismic sea waves.
    All the available information has been compiled from historical accounts,
    archives, press reports, magazines and related works.

  9. Ecology and distribution of recent planktonic foraminifera in eastern part of Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, K.K.; Jayalakshmy, K.V.; Kutty, M.K.

    (0-200 m) than in the surface (0-10 m) tows. Further, latitudinal gradient of some species which have a definite bearing on hydrography of the sea, has been outlined. Relative production of planktonic foraminifera shows that it is high in the southern...

  10. Physical control of primary productivity on a seasonal scale in central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Madhupratap, M.; DileepKumar, M.; Gauns, M.; Muraleedharan, P.M.; Sarma, V.V.S.S.; DeSouza, S.N.

    Using in situ data collected during 1992-1997, under the Indian programme of Joint Global Ocean Flux Study (JGOFS), it is shown that the biological productivity of the Arabian Sea is tightly coupled to the physical forcing mediated through nutrient...

  11. Influence of eastern Arabian Sea on summer monsoon rainfall over west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Rao, M.S.; Rao, M.V.

    and distant nature. In order to realise the model results and the influence of Arabian sea in the context of long range forecasting of monsoon rainfall, we have examined the correlation between the rainfall over west coast of India and premonsoon thermal...

  12. Distribution of (137)Cs in the Mediterranean mussel (Mytilus galloprovincialis) in Eastern Black Sea Coast of Turkey.

    Science.gov (United States)

    Baltas, H; Kiris, E; Dalgic, G; Cevik, U

    2016-06-15

    This study presents the results of (137)Cs and (40)K radionuclide concentrations in mussel (Mytilus galloprovincialis) samples collected during the period of February-November 2014 from twelve different stations within the border of the eastern Black Sea region of Turkey. Also, these radionuclide concentrations were determined in sea water and sediment samples. The activity concentrations in seawater, sediment and mussel tissue samples were between 1.12-1.69mBqL(-1), 3.26-30.74 and 1.61-3.16Bqkg(-1) for (137)Cs and 231.41-399.49mBqL(-1), 215.71-450.07 and 286.84-382.16Bqkg(-1) for (40)K, respectively. These values are also in accordance with the concentrations reported for similar regions. Additionally, radiological impact parameters such as daily intake of (137)Cs and (40)K, annual committed effective dose and carcinogenic risk due to the consumption of mussel were calculated and compared with the international data. Lifetime cancer risk values are lower than the limit of 10(-3). Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. New evidence of the Monchique - Madeira hot spot volcanism at the Coral Patch seamount, Central Eastern Atlantic Sea

    Science.gov (United States)

    D'Oriano, F.; Angeletti, L.; Laurenzi, M. A.; Trua, T.; Capotondi, L.; Taviani, M.; Torelli, L.; Zitellini, N.

    2009-12-01

    Detailed swath bathymetry, high resolution seismic profiles and bottom sampling, collected during the SWIM 2005 and SWIM 2005 cruises, provide new data to constrain the emplacement mechanism of the Monchique-Madeira hotspot in the Central - Eastern Atlantic Sea. During last decades, although this volcanic province has been the object of several investigations, the location of hotspot track and the alignments of the volcanic centers, such as Ormonde, Ampere and Coral Patch seamounts, are still matter of debate. Several alkaline volcanic centers are recognized at Coral Patch and volcanic rocks obtained from the top of the seamount provides a radiometric (40Ar-39Ar) age of 31.4±1.98 Ma. Our data suggest that volcanism was emplaced on the top of a preexistent seamount and was strongly affected by the regional tectonic compressive regime, active on this sector of the Africa Eurasia plate boundary since Oligocene. The compression formed lithospheric scale structures acting as a reserved lane for the upwelling of mantle material during the transit of the hotspot. Lithified pelagic carbonates, infilling fissures in lava blocks and hosting planktic foraminifers, permit to date at the Chattian (24-28 Ma) the first documentation of Coral Patch acting as an offshore terrigenous-starved deep seamount. This situation protracts to recent times as shown by the occurrence of veneers of foraminifer-pteropod oozes and deep-sea mollusc-coral hash and pelagic limestones as the sole sediment types recovered from Coral Patch.

  14. Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes.

    Science.gov (United States)

    Ge, Zhen-Ming; Wang, Heng; Cao, Hao-Bin; Zhao, Bin; Zhou, Xiao; Peltola, Heli; Cui, Li-Fang; Li, Xiu-Zhen; Zhang, Li-Quan

    2016-06-23

    The impacts of sea-level rise (SLR) on coastal ecosystems have attracted worldwide attention in relation to global change. In this study, the salt marsh model for the Yangtze Estuary (SMM-YE, developed in China) and the Sea Level Affecting Marshes Model (SLAMM, developed in the U.S.) were used to simulate the effects of SLR on the coastal salt marshes in eastern China. The changes in the dominant species in the plant community were also considered. Predictions based on the SLAMM indicated a trend of habitat degradation up to 2100; total salt marsh habitat area continued to decline (4-16%) based on the low-level scenario, with greater losses (6-25%) predicted under the high-level scenario. The SMM-YE showed that the salt marshes could be resilient to threats of SLR through the processes of accretion of mudflats, vegetation expansion and sediment trapping by plants. This model predicted that salt marsh areas increased (3-6%) under the low-level scenario. The decrease in the total habitat area with the SMM-YE under the high-level scenario was much lower than the SLAMM prediction. Nevertheless, SLR might negatively affect the salt marsh species that are not adapted to prolonged inundation. An adaptive strategy for responding to changes in sediment resources is necessary in the Yangtze Estuary.

  15. Distribution of metals and extent of contamination in sediments from the south-eastern Baltic Sea (Lithuanian zone

    Directory of Open Access Journals (Sweden)

    Nijolė Remeikaitė-Nikienė

    2018-04-01

    Full Text Available Summary: The distribution of metals (Pb, Cu, Cd, Ni, Cr, Zn in surface sediments and the potential pollution sources in the south-eastern part (SE of the Baltic Sea (Lithuanian zone were investigated in relation to the environmental characteristics (amount of fine-grained particles, TOC content in sediments, origin of sedimentary organic matter, salinity, water depth in 2011–2014. The higher metal concentrations were measured in sediments of the Curonian Lagoon and in the open waters. An approach using various environmental indices (enrichment factor EF, geoaccumulation index Igeo and contamination factor CF was used to quantitatively assess a contamination degree. The principal component analysis (PCA was applied in order to further scrutinize pollution from metal sources. The values of the contamination indices showed no/very low sediment contamination with Ni and Cr, minor–moderate contamination with Cu, Zn and Pb and moderate–considerable pollution with Cd. The strong relationships among metals suggested their similar distribution pattern and a combination of natural and anthropogenic sources. The higher metal concentrations coincided with an increasing amount of fine-grained fraction and organic carbon. In the territorial waters, the distribution of elements was related to the water depth. In addition, the binding of metals with insoluble iron sulphides might explain their high concentrations at the most remote and deepest stations. Keywords: Metals, Enrichment factor, Geoaccumulation index, Contamination factor, The Baltic Sea, The Curonian Lagoon

  16. Transboundary transport of anthropogenic sulfur in PM2.5 at a coastal site in the Sea of Japan as studied by sulfur isotopic ratio measurement

    International Nuclear Information System (INIS)

    Inomata, Yayoi; Ohizumi, Tsuyoshi; Take, Naoko; Sato, Keiichi; Nishikawa, Masataka

    2016-01-01

    Sulfur isotopic ratios (δ 34 S) in size separated aerosol particles (PM2.5 and coarse particles) were measured at Niigata-Maki facing the Sea of Japan. Non-sea salt δ 34 S (δ 34 S nss ) in PM2.5 showed seasonal variations with relatively high values in winter (1.0–3.9‰ in spring, 2.8–4.5‰ in summer, 1.3–4.5‰ in autumn, 3.7–5.7‰ in winter). Taking into consideration air mass transport routes, δ 34 S nss in the air masses which originated in the Asian continent and were transported over the Sea of Japan to the monitoring sites were higher than those values for air masses which were transported over the Japanese islands after leaving the Asian continent for each season. Considering that the δ 34 S nss in sulfuric acid derived from domestic emissions in Japan are lower than those of δ 34 S nss in coal, the lower δ 34 S nss for the air mass transported over the Japanese islands suggest that sulfuric acid in PM2.5 modified the δ 34 S nss due to aerosol mixing with sulfuric acid in Japan. Material balance calculations suggested that the relative contribution of transboundary transport in winter was also higher than for other seasons (40–75% in spring, 51–63% in summer, 45–73% in autumn, and 53–81% in winter). In particular, the contribution to the air masses which were transported directly from the Asian continent was relatively large (75% in spring, 59% in autumn, 78% in winter) in comparison with that for the air masses which were transported over Japan. - Highlights: • δ 34 Snss in PM2.5 is effective to estimate contribution of anthropogenic sulfur. • δ 34 Snss have characterized with seasonal variation with high values in winter. • The contribution of transboundary transport is 39-81% at the site facing to the Sea of Japan. • δ 34 Snss in PM2.5 are modified during transport with mixing of domestic sources. • Map of δ 34 S distribution originated from coal in Northeast Asia is developed.

  17. Transboundary transport of anthropogenic sulfur in PM2.5 at a coastal site in the Sea of Japan as studied by sulfur isotopic ratio measurement

    Energy Technology Data Exchange (ETDEWEB)

    Inomata, Yayoi, E-mail: inomata@acap.asia [Asia Center for Air Pollution Research, 1182, Sowa, Niigata, Niigata 950-2144 (Japan); Ohizumi, Tsuyoshi [Asia Center for Air Pollution Research, 1182, Sowa, Niigata, Niigata 950-2144 (Japan); Niigata Prefectural Institute of Public Health and Environmental Sciences, 314-1, Sowa, Niigata, Niigata 950-2144 (Japan); Take, Naoko; Sato, Keiichi [Asia Center for Air Pollution Research, 1182, Sowa, Niigata, Niigata 950-2144 (Japan); Nishikawa, Masataka [National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Tokyo University of Science, 12-1, Ichigaya Funakawara, Shinjuku, Tokyo 162-0826 (Japan)

    2016-05-15

    Sulfur isotopic ratios (δ{sup 34}S) in size separated aerosol particles (PM2.5 and coarse particles) were measured at Niigata-Maki facing the Sea of Japan. Non-sea salt δ{sup 34}S (δ{sup 34}S{sub nss}) in PM2.5 showed seasonal variations with relatively high values in winter (1.0–3.9‰ in spring, 2.8–4.5‰ in summer, 1.3–4.5‰ in autumn, 3.7–5.7‰ in winter). Taking into consideration air mass transport routes, δ{sup 34}S{sub nss} in the air masses which originated in the Asian continent and were transported over the Sea of Japan to the monitoring sites were higher than those values for air masses which were transported over the Japanese islands after leaving the Asian continent for each season. Considering that the δ{sup 34}S{sub nss} in sulfuric acid derived from domestic emissions in Japan are lower than those of δ{sup 34}S{sub nss} in coal, the lower δ{sup 34}S{sub nss} for the air mass transported over the Japanese islands suggest that sulfuric acid in PM2.5 modified the δ{sup 34}S{sub nss} due to aerosol mixing with sulfuric acid in Japan. Material balance calculations suggested that the relative contribution of transboundary transport in winter was also higher than for other seasons (40–75% in spring, 51–63% in summer, 45–73% in autumn, and 53–81% in winter). In particular, the contribution to the air masses which were transported directly from the Asian continent was relatively large (75% in spring, 59% in autumn, 78% in winter) in comparison with that for the air masses which were transported over Japan. - Highlights: • δ{sup 34}Snss in PM2.5 is effective to estimate contribution of anthropogenic sulfur. • δ{sup 34}Snss have characterized with seasonal variation with high values in winter. • The contribution of transboundary transport is 39-81% at the site facing to the Sea of Japan. • δ{sup 34}Snss in PM2.5 are modified during transport with mixing of domestic sources. • Map of δ{sup 34}S distribution originated

  18. Sedimentary sources and processes in the eastern Arabian Sea: Insights from environmental magnetism, geochemistry and clay mineralogy

    Directory of Open Access Journals (Sweden)

    Kumar Avinash

    2016-03-01

    Full Text Available The spatial distribution patterns of surficial sediment samples from different sedimentary domains (shallow to deep-sea regions of the eastern Arabian Sea were studied using sediment proxies viz. environmental magnetism, geochemistry, particle size and clay mineralogy. Higher concentrations of magnetic minerals (high χlf were recorded in the deep-water sediments when compared with the shallow water sediments. The magnetic mineralogy of one of the shallow water samples is influenced by the presence of bacterial magnetite as evidenced from the χARM/χlf vs. χARM/χfd biplot. However, the other samples are catchment-derived. The high correlation documented for χlf, anhysteretic remanent magnetisation (χARM and isothermal remanent magnetisation (IRM with Al indicates that the deep-sea surficial sediments are influenced by terrigenous fluxes which have been probably derived from the southern Indian rivers, the Sindhu (the Indus and the Narmada-Tapti rivers. A lower Mn concentration is recorded in the upper slope sediments from the oxygen minimum zone (OMZ but a higher Mn/Al ratio is documented in the lower slope and deep-sea sediments. Clay minerals such as illite (24–48.5%, chlorite (14.1–34.9%, smectite (10.6–28.7% and kaolinite (11.9–27.5% dominate the sediments of shallow and deep-sea regions and may have been derived from different sources and transported by fluvial and aeolian agents. Organic carbon (OC data indicate a low concentration in the shallow/shelf region (well oxygenated water conditions and deeper basins (increased bottom-water oxygen concentration and low sedimentation rate. High OC concentrations were documented in the OMZ (very low bottom-water oxygen concentration with high sedimentation rate. The calcium carbonate concentration of the surface sediments from the continental shelf and slope regions (<1800 m up to the Chagos-Laccadive Ridge show higher concentrations (average = 58% when compared to deep basin

  19. Eastern Mediterranean sea levels through the last interglacial from a coastal-marine sequence in northern Israel

    Science.gov (United States)

    Sivan, D.; Sisma-Ventura, G.; Greenbaum, N.; Bialik, O. M.; Williams, F. H.; Tamisiea, M. E.; Rohling, E. J.; Frumkin, A.; Avnaim-Katav, S.; Shtienberg, G.; Stein, M.

    2016-08-01

    A last interglacial (Marine Isotope Stage, MIS5e) marine-coastal sequence has been identified along the Galilee coast of Israel, with the type section located at Rosh Hanikra (RH). The microtidal regime and tectonic stability, along with the detailed stratigraphy of the RH shore, make the study region ideally suited for determining relative sea level (RSL) through the MIS5e interval in the eastern Mediterranean. The sequence contains fossilized microtidal subunits at a few meters above the current sea level. Unfortunately, all fossils were found to be altered, so that U-Th datings cannot be considered to represent initial deposition. We contend that U-Th dating of Strombus bubonius shells (recrystallized to calcite) suffices to indicate a lower limit of ∼110 ± 8 ka for the time sea level dropped below the RH sedimentary sequence. The RH-section comprises three main subunits of a previously determined member (the Yasaf Member): (a) a gravelly unit containing the diagnostic gastropod Strombus bubonius Lamarck (Persististrombus latus), which was deposited in the intertidal to super-tidal stormy zone; (b) Vermetidae reef domes indicating a shallow-water depositional environment; and (c) coarse to medium-sized, bioclastic sandstone, probably deposited in the shallow sub-tidal zone. The sequence overlies three abrasion platforms that are cut by tidal channels at elevations of +0.8 m, +2.6 m and +3.4 m, and which are filled with MIS5e sediments. We present a detailed study of the sequence, with emphasis on stratigraphic, sedimentological, and palaeontological characteristics that indicate sea-level changes. Although without precise absolute dating, the stratigraphic sequence of RH through MIS5e allows us to identify a time-series of RSL positions, using the elevations of three stratigraphic subunits. Reconstructed RSL values range from +1.0 m to +7 m (with uncertainly < 1 m), and most fall within a narrow range of +1.0 to +3.3 m. Toward the end of MIS5e, RSL exceeded

  20. MAPPING SUBSURFACE FORMATIONS ON THE EASTERN RED SEA COAST IN JORDAN USING GEOELECTRICAL TECHNIQUES: GEOLOGICAL AND HYDROGEOLOGICAL IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Batayneh Awni T.

    2007-12-01

    Full Text Available During 2006, geoelectrical measurements using the vertical electrical sounding (VES method were conducted on the eastern Red Sea coast in Jordan, using the SYSCAL-R2 resistivity instrument.
    The objectives of the study were (i to evaluate the possibility of mapping of Quaternary sediments medium in areas where little is known about the subsurface geology and to infer shallow geological
    structure from the electrical interpretation, and (ii to identify formations that may present fresh aquifer waters, and subsequently to estimate the relationship between groundwater resources and geological structures. Data collected at 47 locations were interpreted first with curve matching techniques, using theoretically calculated master curves, in conjunction with the auxiliary curves. The initial earth
    models were second checked and reinterpreted using a 1-D inversion program (i.e., RESIX-IP in order to obtain final earth models. The final layer parameters (thicknesses and resistivities were then
    pieced together along survey lines to make electrical cross sections. Resistivity measurements show a dominant trend of decreasing resistivity (thus increasing salinity with depth and westward toward
    the Red Sea. Accordingly, three zones with different resistivity values were detected, corresponding to three different bearing formations: (i a water-bearing formation in the west containing Red Sea saltwater; (ii a transition zone of clay and clayey sand thick formation; (iii stratas saturated with fresh groundwater in the east disturbed by the presence of clay and clayey sand horizons. Deep borehole (131 m drilled in the northwestern part of the study area for groundwater investigation, has
    confirmed the findings of the resistivity survey.

  1. New insights and questions about the Meso-Cenozoic Tectonic evolution of Eastern Black Sea and Caucasus.

    Science.gov (United States)

    Sosson, Marc; Rolland, Yann; Hässig, Marc; Meijers, Maud; Smith, Brigitte; Muller, Carla; Adamia, Shota; Melkonian, Rafael; Kangarli, Talat; Sahakyan, Lilit; Sadradze, Nino; Avagyan, Ara; Galoyan, Ghazar; Alania, Victor; Enukidze, Onice; Sheremet-Korniyenko, Yevgeniya; Yegorova, Tamara

    2014-05-01

    Since last decade a lot of new field researches (supported by MEBE and DARIUS programmes) were carried out in order to clarify the tectonic evolution of the South Caucasus and Eastern Black Sea regions. A summary of these improvements are as following: 1. Evidence of only one suture zone in the Lesser Caucasus: the Sevan-Akera suture zone as the eastward continuity of the Izmir-Ankara-Erzincan one. 2. Timing and modalities of the Upper Cretaceous obduction process of the Sevan-Akera back-arc basin. 3. Paleolatitude reconstruction of the Taurides-Anatolides-South Armenia microplate (TASAM) since the Late Cretaceous 4. Paleocene to Miocene tectonic evolution of the collision zone between Eurasia and the TASAM. 5. Structures and propagation of the Lesser Caucasus and Greater Causasus foreland basins from Paleocene to Miocene. 6. Structures of the inverted Paleocene-Eocene Adjara-Trialeti basin of the Eurasian margin and timing of deformations from Lesser Caucasus to Greater Caucasus. 7. New stratigraphic data from the Crimea Mountain which argues for a Lower Cretaceous rifting of the Eastern Black Sea. According to aforementioned results and previous studies, this widespread zone (from the Eastern Black Sea to the Lesser Caucasus) appears act as a large puzzle of heterogeneous lithospheres (continental, oceanic, arc, back-arc basins) since the Early Cretaceous. This is probably why this area has differently reacted in time and space to the northward collision of the TASAM with Eurasia since the Late Cretaceous and then of Arabian plate since the Oligo-Miocene. It seems that some lithospheres which have cold mantellic behavior (especially the Black Sea) react as rigid blocks, while others with a continental origin, reheated by magmatism, (as the Taurides-Anatolides) were extruded to the west or bended as an orocline (as the Lesser Caucasus, the Pontides). This is why some main questions remain, are not solved and are still debated. 1. The continuity of main structures

  2. Dining hall at sea: feeding migrations of nektonic predators to the eastern Patagonian Shelf.

    Science.gov (United States)

    Arkhipkin, A; Brickle, P; Laptikhovsky, V; Winter, A

    2012-07-01

    Seasonal changes in relative abundance and biomass of nektonic predators were analysed on the eastern Patagonian Shelf and continental slope; one of the most productive large marine ecosystems of the southern hemisphere. Several migratory types were revealed for species belonging to either temperate or sub-Antarctic faunas. Despite high productivity, only a few large nektonic predators spend their entire life cycle on the eastern Patagonian Shelf and use only a small proportion of the meso-nektonic resource. Most of the resource is exploited by non-resident nektonic migrants, which move to the area from distant spawning grounds. Pelagic and demersal sharks and skates, the squid Illex argentinus, tunas and gadoids migrate to the eastern part of the Patagonian Shelf to feed at different times of the year; arriving in seasonal waves according to their life cycle and spawning seasonality. Some deepwater fishes and squid migrate onto the shelf as juveniles to harvest the resource, and then return to deepwater habitat as adults. It is hypothesized that the large biomass of meso-planktonic and meso-nektonic consumers prevents most higher-trophic level predators from establishing spawning populations in this area, as their larvae and fry would be overwhelmed by predation. Instead, the higher-trophic level predators establish spawning and nursery grounds elsewhere and arrive to feed on the meso-planktonic and meso-nektonic resources after they have outgrown their own stages of predation vulnerability. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  3. History of Asian eolian input to the Sea of Japan since 15 Ma: Links to Tibetan uplift or global cooling?

    Science.gov (United States)

    Shen, Xingyan; Wan, Shiming; France-Lanord, Christian; Clift, Peter D.; Tada, Ryuji; Révillon, Sidonie; Shi, Xuefa; Zhao, Debo; Liu, Yanguang; Yin, Xuebo; Song, Zehua; Li, Anchun

    2017-09-01

    We present high-resolution analyses of clay mineral assemblages combined with analysis of Sr-Nd-Pb isotopic compositions of the Japan, in order to trace the sources of clay minerals and reconstruct proxy records of past changes in Asian eolian input to the basin since 15 Ma. The clay mineral assemblages at IODP Site U1430 mainly consist of smectite (∼51%) and illite (∼36%), with minor kaolinite (∼7%) and chlorite (∼6%). Provenance analysis suggests that the fine-grained sediment at the study site is a two end-member mixture of eolian dust from Central Asia and fluvial input from the Japanese islands. The Central Asian end member supplied illite-rich and high 87Sr/86Sr and low εNd(0) eolian dust to the study site by wind, while the Japanese end member, characterized by young volcanic rocks, contributed smectite-rich, low 87Sr/86Sr and high εNd(0) weathering products via rivers. The ratio of illite/smectite and εNd(0) values of clay-sized silicate sediments at Site U1430 were used as proxies for tracing the changing strength of central Asian eolian input to the Sea of Japan, and thus reconstruct the aridification history of its source region. Our study presents for the first time a continuous, high-resolution record that highlights the four-step drying of Central Asia that occurred at ∼11.8 Ma, 8 Ma, 3.5 Ma and 1.2 Ma. Considered the nature and timing of major climatic and tectonic events in Asia, we conclude that the strengthened aridification of Central Asia starting at ∼11.8 Ma was possibly driven by the combined effect of Tibetan surface uplift and global cooling, whereas the rapid drying at ∼8 Ma was caused primarily by the uplift of the northern Tibetan Plateau. In contrast, global cooling, overwhelming the influence of Tibetan Plateau uplift, has become the primary control on Central Asia aridification since ∼3.5 Ma.

  4. Monsoonal reversal of remote sensing biases in latent heat flux over eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Pankajakshan, T.; Sathe, P.V.; Murty, V.S.N.; Santosh, K.R.

    by vapor bearing clouds while the latent heat loss is controlled by several factors such as wind speed, sea surface temperature and the boundary layer humidity gradient (qs-qa). Since the Indian Ocean experiences several contrasting seasons with distinct... certainly have a significant influence on future validation exercises especially over this part of the basin. Acknowledgements: We thank the Director, National Institute of Oceanography, Goa and The Director, Space Application Center, Ahmedabad...

  5. Assessing Evaporation Duct Variability In The Eastern Mediterranean Sea In Support Of Radar And Radio Communications

    Science.gov (United States)

    2016-12-01

    close to the coast (HMSO 1962). The average depth of the Mediterranean Sea is 1,500 meters (m), the deepest part being 5,121 m at the Matapan trench...European Center for Medium-Range Weather Forecasts (ECMWF) surface reanalysis data from 1990 to 2015 are used. The Coupled Ocean -Atmosphere Response...Forecasts (ECMWF) surface reanalysis data from 1990 to 2015 are used. The Coupled Ocean - Atmosphere Response Experiment (COARE) bulk surface flux

  6. Spawning phenology and geography of Aleutian Islands and eastern Bering Sea Pacific cod (Gadus macrocephalus)

    Science.gov (United States)

    Neidetcher, Sandra K.; Hurst, Thomas P.; Ciannelli, Lorenzo; Logerwell, Elizabeth A.

    2014-11-01

    Pacific cod (Gadus macrocephalus) is an economically and ecologically important species in the southeastern Bering Sea and Aleutian Islands, yet little is known about the spawning dynamics of Pacific cod in these regions. To address this knowledge gap, we applied a gross anatomical maturity key for Pacific cod to describe temporal and spatial patterns of reproductive status over three winter spawning seasons: 2005, 2006, and 2007. Maturity status of female Pacific cod was assessed by fishery observers during sampling of commercial catches and used to construct maps showing spawning activity in the Bering Sea and Aleutian Islands. Most spawning activity was observed on the Bering Sea shelf and Aleutian Island plateaus between 100 and 200 m depth. Data for those days when a high percentage of spawning stage fish were observed were used to identify areas with concentrations of spawning fish. Spawning concentrations were identified north of Unimak Island, in the vicinity of the Pribilof Islands, at the shelf break near Zhemchug Canyon, and adjacent to islands in the central and western Aleutian Islands along the continental shelf. The spawning season was found to begin in the last days of February or early March and extend through early to mid-April. Variation in spawning time (averaging ~10 days between years) may have been associated with a change from warm (2005) to cold (2007) climate conditions during the study period. Our information on Pacific cod spawning patterns will help inform fishery management decisions, models of spawning and larval dispersal and the spatial structure of the stock.

  7. Plasma lead, silicon and titanium concentrations are considerably higher in green sea turtle from the suburban coast than in those from the rural coast in Okinawa, Japan.

    Science.gov (United States)

    Tsukano, Kenji; Suzuki, Kazuyuki; Noda, Jun; Yanagisawa, Makio; Kameda, Kazunari; Sera, Koichiro; Nishi, Yasunobu; Shimamori, Toshio; Morimoto, Yasuyo; Yokota, Hiroshi; Asakawa, Mitsuhiko

    2017-12-22

    The purpose of this study was to compare the concentration of trace elements in the plasma of sea turtles that inhabited the suburban (Okinawa Main Island, n=8) and the rural coast (Yaeyama Island, n=57) in Okinawa, Japan. Particle induced X-ray emission allowed detection of 20 trace and major elements. The wild sea turtles in the suburban coast in Okinawa were found to have high concentrations of Pb, Si and Ti in the plasma when compared to the rural area but there were no significant changes in the Al, As and Hg concentrations. These results may help to suggest the status of some elements in a marine environment. Further, monitoring the plasma trace and major element status in sea turtles can be used as a bio-monitoring approach by which specific types of elements found here could indicate effects that are related to human activities.

  8. Ethnobotany of medicinal plants used in Eastern Mallorca (Balearic Islands, Mediterranean Sea).

    Science.gov (United States)

    Carrió, Esperança; Vallès, Joan

    2012-06-14

    This paper represents the first large-scale ethnobotanical study in the island of Mallorca, and provides significant information on pharmaceutical plant uses, built up from interviews with native people from this touristic hotspot, demonstrating its ethnopharmacological importance. To collect, analyse and evaluate the ethnobotanical knowledge concerning medicinal plants in a north-eastern Mallorcan area (municipalities of Artà, Capdepera and Son Servera; 298 km2, 31,764 inhabitants). We performed semi-structured interviews with 42 informants (mean age 77; 40% women, 60% men), identified the plant taxa reported and analysed the results, comparing them with those found in the current Mallorcan ethnobotanical information and in other territories. The informants reported data on 121 human medicinal plants representing 64 botanical families. Around 45 medicinal uses reported, concerning 37 species, have not or have very rarely been cited as medicinal. An index of medicinal importance is proposed. All efforts addressed to compiling ethnobotanical information in industrialised or touristised areas such as Eastern Mallorca are still valuable. New possibilities can be explored to give practical value to Mallorcan ethnobotanical data in the frame of considering traditional plant knowledge as part of the islanders’ lifestyle and healthy habits.

  9. Environmental policy in the north-eastern sector of the Black sea coast

    Science.gov (United States)

    Kosyan, Ruben; Godin, Evgenii; Kosyan, Alisa

    2015-04-01

    Active economic development of the Black Sea East coastal zone has started in the beginning of 20-th century. Those days the pebble taken from beaches was used for construction of buildings, rail and motor roads. Active consumption of pebble from the beaches and river banks had caused a sharp increase of sea shores abrasion and washout rate, number of landslides had also increased. Contemporary Caucasian shores of Black Sea are being developed under increasing man-caused load. Favorable natural conditions, their variety and uniqueness determine the exceptional role of these shores as very important recreational zone of Russian South. Waste urbanized areas, agricultural territories and National Parks are located in immediate neighborhood with the sea. Important industrial facilities and federal and international communi- cations, including major seaports are located in the shore zone. At present time major gas and oil transportation facilities are commissioned and being constructed in the area. Due to the change of geopolitical situation the Russian shoreline had significantly reduced in comparison with Soviet period, especially in most developed regions. Large resort complexes in Georgia, Crimea and Baltic area were lost. Russia had also lost many major seaports that, under conditions of structural change of economy and export growth, had caused the necessity of building new industrial facilities in the Black Sea coastal zone, and, consequently, had stimulated active human invasion into natural coastal processes. At the time being, a major part (three hundred nine kilometers) of Black Sea coast within Russian sector is subject to abrasion and landslide processes. Abrasion process and beaches wash-out, landslides cause destruction of industrial and transport facilities, living and public buildings, resort complexes and valuable agricultural areas. In this light, the challenge of estimation of effective methods of shores protection against wave-induced erosion

  10. Three Kanto Earthquakes Inferred from the Tsunami Deposits and the Relative Sea Level Change in the Miura Peninsula, Central Japan

    Science.gov (United States)

    Kim, H.; Shimazaki, K.; Chiba, T.; Ishibe, T.; Okamura, M.; Matsuoka, H.; Tsuji, Y.; Satake, K.

    2010-12-01

    The Kanto earthquake is a great interplate earthquake caused by subduction of the Philippine Sea Plate beneath the Japan Island along the Sagami Trough. The 1923 Kanto earthquake (M=7.9) and the 1703 Kanto earthquake (M~8.0) are two of the most devastating earthquake those struck Tokyo Metropolitan area, respectively. These earthquakes brought large (~5 m) tsunami to the coast area and uplifted the Miura peninsula by ~1.4 m. The tide gauge station, moreover, records the subsidence during the interseismic period before and after the 1923 earthquake. Present study clarifies the past Kanto earthquake prior to the 1703 earthquake based on the sedimentary analysis in the Koajiro bay of the southern Miura Peninsula. The continuous samples of inner bay fine sediments were taken by the boring survey using 3-m-long geoslicer. Three layers of coarse sediments, T1, T2, and T3 units from top toward bottom, are observed in the bay sediments at almost all the sites. These units are composed of mixture of materials such as shell fragments, rock clasts and gravel, and some of units have eroded the lower fine sediments, indicating the event deposits by the strong traction flow. The grain sizes of the bay sediments are grading upward and abruptly become larger after the deposition of the T1, T2 and T3 units. Very little diatom is observed in these units, but the total number of diatoms increase in the bay sediments. The ratio of the marine planktonic species against the benthic species gradually rises from the lower part to the upper part in the bay sediment. In the tidal flat sediment, the freshwater planktonic species appear in place of the marine planktonic diatom. The changes of grain size and diatom species make a presumption that the sea depth suddenly becomes shallow by the event and deeper during the interseismic period. The T1, T2 and T3 units, thus, are correlated with the tsunami deposits conveyed by the Kanto earthquake. The T1 and T2 units are inferred to be the tsunami

  11. Two-dimensional thermal modeling associated with subduction of the Philippine Sea plate in southern Kyushu, Japan

    Science.gov (United States)

    Suenaga, Nobuaki; Yoshioka, Shoichi; Matsumoto, Takumi; Ji, Yingfeng

    2018-01-01

    In Hyuga-nada, southern Kyushu in southwest Japan, afterslip events were found in association with the two large interplate earthquakes, which occurred on October 19 and December 3, 1996. In Kyushu, low-frequency earthquakes (LFEs) and tectonic tremors are not common, but a considerable concentration of tectonic tremors is observed beneath the Pacific coast of the Miyazaki prefecture. To investigate the generation mechanisms of these seismic events, we performed 2-D box-type time-dependent thermal modeling in southern Kyushu. As a result, the temperature range of the upper surface of the subducting Philippine Sea (PHS) plate, where the afterslip occurred, reached approximately 300 to 350 °C. The temperatures where the tectonic tremors occurred ranged from 450 to 650 °C in the mantle wedge corner. We also estimated the spatial distribution of water content within the subducting PHS plate, using phase diagrams of hydrous mid-ocean ridge basalt (MORB) and ultramafic rock. Then, we found that no characteristic phase transformations accompany the dehydration of the subducting PHS plate in the afterslip region, but phase transformation from lawsonite blueschist to lawsonite eclogite is expected within the oceanic crust of the PHS plate just below the active region of the tectonic tremors. Our estimated water content distribution is consistent with the VP/VS ratio calculated from the seismic tomography. Therefore, we conclude that the occurrence of the afterslip is controlled by the temperature condition at the plate boundary, and occurs near the down-dip limit of the seismogenic zone. On the other hand, determining the major factors leading to the occurrence of the tectonic tremors is difficult, we estimated the temperature in the mantle wedge is ranging from 450 °C to 650 °C, and dehydration of 1.0 wt% would be expected from the subducting PHS plate near the active region of the tectonic tremors.

  12. Comparison of biochemical compositions of phytoplankton during spring and fall seasons in the northern East/Japan Sea

    Science.gov (United States)

    Kang, Jae Joong; Joo, HuiTae; Lee, Jae Hyung; Lee, Jang Han; Lee, Ho Won; Lee, Dabin; Kang, Chang Keun; Yun, Mi Sun; Lee, Sang Heon

    2017-09-01

    The East/Japan Sea (EJS) where is surrounded by the Korean peninsula, the Japanese islands, and the Russian coast has been experiencing a large change in physicochemical properties. Based on biochemical composition analysis (carbohydrates, proteins, and lipids), the current qualitative status of phytoplankton was identified in the northern EJS from two different sampling seasons (fall and spring in 2012 and 2015, respectively). The average chlorophyll-a (chl-a) concentration integrated from the euphotic depths was significantly higher in 2015 (99.3 ± 69.2 mg m-2) than 2012 (21.5 ± 6.7 mg m-2). Large phytoplankton (> 2 μm) were predominant in 2015 accounting for 64.5 ± 19.7% whereas small-size phytoplankton (0.7-2 μm) were dominant (49.1 ± 17.5%) in 2012. The biochemical compositions of phytoplankton were predominated by lipids (42.6 ± 7.8%) in 2012 whereas carbohydrate composition largely contributed (53.2 ± 11.7%) to the total biochemical composition in 2015, which is mainly due to different nutrient availabilities and growth stages. Interestingly, the averaged FM concentrations and calorific values for phytoplankton based on the biochemical compositions had similar values between the two years, although the integrated chl-a concentrations were substantially different between 2012 and 2015. In terms of different cell sizes of phytoplankton, we found that small phytoplankton assimilate more FM and calorific energy per unit of chl-a concentration than total phytoplankton. Our results are meaningful for the understanding of future marine ecosystems where small phytoplankton will become dominant at a scenario of ongoing warmer oceans.

  13. Crustal characteristic variation in the central Yamato Basin, Japan Sea back-arc basin, deduced from seismic survey results

    Science.gov (United States)

    Sato, Takeshi; No, Tetsuo; Miura, Seiichi; Kodaira, Shuichi

    2018-02-01

    The crustal structure of the Yamato Bank, the central Yamato Basin, and the continental shelf in the southern Japan Sea back-arc basin is obtained based on a seismic survey using ocean bottom seismographs and seismic shot to elucidate the back-arc basin formation processes. The central Yamato Basin can be divided into three domains based on the crustal structure: the deep basin, the seamount, and the transition domains. In the deep basin domain, the crust without the sedimentary layer is about 12-13 km thick. Very few units have P-wave velocity of 5.4-6.0 km/s, which corresponds to the continental upper crust. In the seamount and transition domains, the crust without the sedimentary layer is about 12-16 km thick. The P-wave velocities of the upper and lower crusts differs among the deep basin, the seamount, and the transition domains. These results indicate that the central Yamato Basin displays crustal variability in different domains. The crust of the deep basin domain is oceanic in nature and suggests advanced back-arc basin development. The seamount domain might have been affected by volcanic activity after basin opening. In the transition domain, the crust comprises mixed characters of continental and oceanic crust. This crustal variation might represent the influence of different processes in the central Yamato Basin, suggesting that crustal development was influenced not only by back-arc opening processes but also by later volcanic activity. In the Yamato Bank and continental shelf, the upper crust has thickness of about 17-18 km and P-wave velocities of 3.3-4.1 to 6.6 km/s. The Yamato Bank and the continental shelf suggest a continental crustal character.

  14. Baleen whale abundance and distribution in relation to environmental variables and prey density in the Eastern Bering Sea

    Science.gov (United States)

    Zerbini, Alexandre N.; Friday, Nancy A.; Palacios, Daniel M.; Waite, Janice M.; Ressler, Patrick H.; Rone, Brenda K.; Moore, Sue E.; Clapham, Phillip J.

    2016-12-01

    The Bering Sea is one of the most productive marine ecosystems in the world and an important habitat for various marine mammal species. Once abundant in this region, most baleen whale species were severely depleted by commercial whaling in the 19th and early 20th centuries. Since their protection in mid-20th century, baleen whale populations have been recovering and reoccupying their historical habitats. These species can consume large amounts of their prey and thus can modify the local structure of ecosystems. Characterizing the extent to which environmental conditions and prey density influence baleen whale abundance in the Eastern Bering Sea is essential to improve our understanding of ecosystem dynamics and to predict how these species might respond to ecosystem variability associated with climate changes. In this study, physiographic, oceanographic, and biological datasets from 2008 to 2010 were combined to model the habitat characteristics of fin whales, humpback whales, and minke whales in the EBS in early summer (June and July) using generalized additive models (GAMs). The explained deviances of the best-supported models were 54.9%, 20.6%, and 68.3% for minke, fin and humpback whales, respectively. Minke and fin whales had similar distribution patterns in the EBS but their abundance was predicted by different explanatory variables. Euphausiid and pollock biomasses, and depth were important predictors of minke whale numbers, while distance to shore, euphausiid biomass, distance to the 200 m isobath, and chlorophyll-a concentration better explained fin whale abundance. Humpback whales showed a preference for shallow, coastal waters north of the Alaska Peninsula. For this species, sea surface temperature, depth, chlorophyll-a concentration and euphausid biomass were important predictors of abundance. This study is the first to provide a habitat baseline for baleen whales in the EBS based on a quantitative assessment of the relationship between whale abundance

  15. The drift of Modified Atlantic Water from the Alboran Sea to the eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    J. Font

    1998-09-01

    Full Text Available The Algerian basin is a region of the western Mediterranean with a highly variable circulation structure, including the eastward transport of Modified Atlantic Water (MAW in its surface layer. An experiment with satellite tracked Lagrangian drifters was performed in 1996-97 to analyse the mesoscale circulation of the Algerian current. The complete trajectories of 18 drifters indicate that, at basin scale, all the surface flow occured along the coast from the Alboran Sea to the strait of Sicily. At that time, no portion of the inflowing MAW was driven to the central or northern regions.

  16. Tracing the strength of the southwest monsoon using boron isotopes in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.; Naidu, P.D.; Foster, G.L.; Martínez-Boti, M.A.

    , was further calculated using pH, SST, salinity and TA (derived from salinity using the local modern day relationship between salinity and alkalinity from the GLODAP dataset) [Key et al., 2004]. We have used the R version 2.15.3 for these calculations (R... precipitation on the Western Ghats drains into the EAS through numerous rivers and streams. Modern observations indicate that pCO2sw in the Arabian Sea as a whole is in excess of that in the atmosphere, therefore acting as a significant source of carbon...

  17. Phosphorus and iron speciation of the Japan Sea sediments 30 220 kyr ago (IODP Exp. 346): Implications for the evolution of Asian Monsoon climate system

    Science.gov (United States)

    Masuda, S.; Yamaguchi, K. E.; Ikehara, M.; Takahashi, S.; Yamaguchi, A.; Tada, R.

    2017-12-01

    The Asian monsoon system established about 50 Ma due to uplift of the Himalaya and Tibetan Plateau. Monsoon influences atmospheric circulation, rainfall, weathering, riverine transport, and ocean nutrients budget, which were recorded in the sediments of the Japan Sea, where cm-scale alternation of Corg-rich and Corg-poor layers accumulated during the Quaternary. This alternation is caused by temporal changes in the nutrient supply to the sea and consequent changes in its bottom water conditions. Contribution of high-P East China Sea coastal water to the Tsushima Current is important since the current supplies >99% of dissolved P into the sea. Increased rainfall in East Asia promotes input of freshwater into the northern East China Sea, which induces upwelling of nutrient-rich Kuroshio subsurface water that eventually flow into the Japan Sea through the Tsushima Strait. To gain insights into the evolving oceanic redox state and its relation with the monsoon system, we conducted C, Fe and P speciation analyses for the sediments from the northeastern (Site U1423) and central (Site U1425) parts of the Japan Sea. The samples were quantified for five P-bearing species (Pabs, PFe, Pauth, Pdet and Porg) by modified SEDEX method of Ruttenberg (1992) and four Fe-bearing species (FeHCl, Fecarb, Feox and Femag) by the method of Poulton et al. (2005). The abundance and the stable isotope compositions of organic carbon were measured using EA-irMS at the Center for Advanced Marine Core Research, Kochi University. The most abundant P-bearing species is Pauth (Ave. 0.044 wt.%), followed by Porg (Ave. 0.016 wt.%) that show negative correlation with Pauth contents. These results suggest that organic matter produced in the surface ocean was decomposed to release phosphate, which eventually formed authigenic apatite in the sediments, implying that the ocean was oxic and/or biological activity was enhanced. Dark layers are generally rich in P and Fe, suggesting active summer monsoon.

  18. Vegetation Analysis in the Red Sea-Eastern Desert Ecotone at the Area between Safaga and South Qusseir, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed G. Sheded

    2014-12-01

    Full Text Available The current work is concerned with the studying the impact of environmental conditions on the vegetation in the arid ecotone located between Red Sea and Eastern Desert from Safaga to south Qusseir. Ninety eight quadrats inside 13 transects were selected to cover the environmental gradient across the ecotone, from the coastal region to the boundary of Eastern Desert. Forty five species were recorded belonged to 24 different families and 38 genera. The perennial species were 38 while the annuals were seven species. Zygophyllum coccineum had the highest presence value (89.8% followed by Tamarix nilotica (56.1% and Zilla spinosa (51.02%. Chamaephytes and Hemicryptophytes were the most prevailed life-forms. Chrological analysis exhibited that SaharoSindian and Sahro-Sindian with its extension to Sudano-Zambezian elements were the most dominant. TWINSPAN classification technique produced three vegetation groups include nine clusters at the fourth level. These groups identified according to the first and second dominant species as follows: Convolvulus hystrix - Panicum turgidum, Tamarix aphylla - Limonium pruinosum and Nitraria retusa - Tamarix nilotica. DECORANA results indicated a reasonable segregation among these groups along the ordination axis 1 and 2. Vegetation analysis showed that ecotonal clusters have highest number of species/cluster, high species richness and high species turnover. Therefore, the largest group existed in the ecotone (34 species while the desert group contained eight species and the coastal group included three species. Among the estimated soil variables in this study, pH, coarse sand, HCO3-, SO42- , clay and PO43- have the highest effect on species distribution. Sodium adsorption ratio (SAR was the effective factor in detecting the ecotonal species, Aeluropus lagopoides and Limonium pruinosum.

  19. Status of 137Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ( 134 Cs and 137 Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct 137 Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, 137 Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed 137 Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow 137 Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported 137 Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of 137 Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of 137 Cs, i.e. contaminated

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

    Directory of Open Access Journals (Sweden)

    A. SIOULAS

    2000-12-01

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

  1. The Temporal Dynamics of Coastal Phytoplankton and Bacterioplankton in the Eastern Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Ofrat Raveh

    Full Text Available This study considers variability in phytoplankton and heterotrophic bacterial abundances and production rates, in one of the most oligotrophic marine regions in the world-the Levantine Basin. The temporal dynamics of these planktonic groups were studied in the coastal waters of the southeastern Mediterranean Sea approximately every two weeks for a total of two years. Heterotrophic bacteria were abundant mostly during late summer and midwinter, and were positively correlated with bacterial production and with N2 fixation. Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates. Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients. Furthermore, a comparison of our results with results from the open Levantine Basin demonstrates that autotrophic and heterotrophic production, as well as N2 fixation rates, are considerably higher in the coastal habitat than in the open sea, while nutrient levels or cell abundance are not different. These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

  2. Information, attitude, and behavior toward organ transplantation and donation among health workers in the eastern Black Sea region of Turkey.

    Science.gov (United States)

    Topbaş, M; Türkyilmaz, S; Can, G; Ulusoy, S; Kalyoncu, M; Kaynar, K; Yavuzyilmaz, A; Kiliç, E; Ari, S; Ari, B

    2011-04-01

    We sought to evaluate the information, attitude, and behaviors toward organ donation among health workers in the eastern Black Sea region of Turkey. This descriptive study was performed between December 2008 and November 2009. It involved 1,545 health personnel in 8 state hospitals in the eastern Black Sea region of Turkey, excluding the university hospitals in the towns of Trabzon, Rize, Gümüşhane, and Giresun. Educational seminars regarding organ transplantation and donation were arranged for the hospitals in the study. Questionnaires on the subject distributed to the participants were collected before the seminars began. They contained questions about occupation, gender, age, previous organ donation, whether the person would consider donating if they had not already volunteered (if not, the reasons why), whether any relatives had volunteered to donate organs, whether anyone close to them had volunteered to donate organs, whether they would donate organs in the event of a relative's death, and what they might think if they were to require an organ transplant. Following the seminars, participants were given the opportunity to obtain organ donation cards from a stand on site. Data were analyzed using the chi-square test. Eighty-one participants (5.2%), including 46 women (5.2%) and 35 men (5.3%), had previously officially volunteered to donate organs (P = .875). One hundred thirty-seven health personnel were willing to donate organs by visiting the donation stand after the seminars. The main reasons for participants who had not volunteered to donate organs failing to do so were lack of information about donation and procedures (28.4%), lack of interest in the subject (23.2%), and Islamic religious beliefs and/or traditions (19.6%). One hundred eighty health personnel (11.7%) had family members or relatives who had volunteered to donate organs. Asked whether they would donate that person's organs in the event of the death of a relative, 93 doctors (67.6%), 225

  3. Biogenic Methane Generation Potential in the Eastern Nankai Trough, Japan: Effect of Reaction Temperature and Total Organic Carbon

    Science.gov (United States)

    Aung, T. T.; Fujii, T.; Amo, M.; Suzuki, K.

    2017-12-01

    Understanding potential of methane flux from the Pleistocene fore-arc basin filled turbiditic sedimentary formation along the eastern Nankai Trough is important in the quantitative assessment of gas hydrate resources. We considered generated methane could exist in sedimentary basin in the forms of three major components, and those are methane in methane hydrate, free gas and methane dissolved in water. Generation of biomethane strongly depends on microbe activity and microbes in turn survive in diverse range of temperature, salinity and pH. This study aims to understand effect of reaction temperature and total organic carbon on generation of biomethane and its components. Biomarker analysis and cultural experiment results of the core samples from the eastern Nankai Trough reveal that methane generation rate gets peak at various temperature ranging12.5°to 35°. Simulation study of biomethane generation was made using commercial basin scale simulator, PetroMod, with different reaction temperature and total organic carbon to predict how these effect on generation of biomethane. Reaction model is set by Gaussian distribution with constant hydrogen index and standard deviation of 1. Series of simulation cases with peak reaction temperature ranging 12.5°to 35° and total organic carbon of 0.6% to 3% were conducted and analyzed. Simulation results show that linear decrease in generation potential while increasing reaction temperature. But decreasing amount becomes larger in the model with higher total organic carbon. At higher reaction temperatures, >30°, extremely low generation potential was found. This is due to the fact that the source formation modeled is less than 1 km in thickness and most of formation do not reach temperature more than 30°. In terms of the components, methane in methane hydrate and free methane increase with increasing TOC. Drastic increase in free methane was observed in the model with 3% of TOC. Methane amount dissolved in water shows almost

  4. On the continuous functioning of an internal mechanism that drives the Eastern Mediterranean thermohaline circulation: The recent activation of the Aegean Sea as a dense water source area

    Science.gov (United States)

    Krokos, George; Velaoras, Dimitris; Korres, Gerasimos; Perivoliotis, Leonidas; Theocharis, Alexander

    2014-01-01

    The scientific interest in Eastern Mediterranean (EMed) processes of major importance has been revived in recent years due to the predominance of internal variability manifested in a decadal time scale leading to the alternating activation of the two dense water sources (i.e. the Adriatic and Aegean Seas). Analysis of available hydrographic data during the 2003-2012 period reveals an anticorrelated almost decadal oscillation in the thermohaline properties of the upper and intermediate water masses in both the Ionian and the Levantine/Aegean Seas. This event is the manifestation of an ongoing internal mechanism initially introduced by Theocharis et al. (in press) which periodically disturbs the upper thermohaline EMed conveyor belt and changes the respective water mass pathways, thus driving the alternating activation of the two dense water sources through salinity preconditioning. Since 2004-2005, the salinity of the upper/intermediate layer in the eastern part of the EMed gradually increased up to 2010, while at the same time it decreased in the North Ionian Sea. During the same period we observed the activation of the Aegean Sea as a Dense Water Formation area even though the atmospheric forcing conditions were not favorable. After 2010 the salinity trend reversed in both regions. This suggests that in the near future the salinity preconditioning of the Adriatic Sea will be favored again following the respective water mass pathway changes.

  5. Cetacean line-transect survey conducted in the eastern Bering Sea shelf by Alaska Fisheries Science Center, National Marine Mammal Laboratory from NOAA Ship Miller Freeman from 1999-07-07 to 2004-06-30 (NCEI Accession 0131862)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC’s echo integration trawl surveys for...

  6. AFSC/RACE/EcoFOCI: NPRB project number 926: Assessing the condition of walleye pollock, Theragra chalcogramma, larvae in the eastern Bering Sea with muscle-based flow cytometry cell cycle analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Walleye pollock are an important component of the eastern Bering Sea ecosystem due to their vast numbers and biomass and are of great commercial importance. Their...

  7. Hydrological, plankton and pigment observations in the Makassar Strait, Madura Strait and Eastern Java Sea by the R.V. Samudera, April 16 to May 19, 1975 (NODC Accession 7700306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton and chemical data were collected using net and bottle casts from the R.V. SAMUDERA in the Makassar Strait, Madura Strait and Eastern Java Sea from 16...

  8. Spatial distribution and dietary overlap between Japanese anchovy Engraulis japonicus and moon jellyfish Aurelia aurita in the Seto Inland Sea, Japan

    Directory of Open Access Journals (Sweden)

    Jun Shoji

    2009-10-01

    Full Text Available Biological and physical surveys were conducted in order to investigate the relationship between environmental conditions and the distribution of ichthyoplankton and jellyfish, and dietary overlap between the ichthyoplankton and jellyfish in the Seto Inland Sea (SIS, Japan. Ichthyoplankton, copepods, and jellyfish were collected during two cruises in July 2005 in the Sea of Hiuchi and in July 2006 in Hiroshima Bay within the SIS. Sea surface temperature (˚C, salinity, bottom-layer dissolved oxygen (mg l-1 and the abundance (no. m-2 of fish eggs and larvae were significantly higher in the Sea of Hiuchi. Japanese anchovy was most dominant (69.3% in number of eggs and 52.3% in number of larvae among the ichthyoplankton. Mean jellyfish biomass (g m-2 in Hiroshima Bay was significantly higher (50-folds than that in the Sea of Hiuchi. Moon jellyfish was the most dominant among the jellyfish collected, accounting for 85.6% in wet weight. Surface temperature had a significant effect on fish egg and larval distribution: abundance of fish eggs and larvae increased with increasing temperature. Jellyfish abundance was negatively correlated with the bottom-layer oxygen concentration. Stable isotope analysis indicated dietary overlap between the Japanese anchovy and the moon jellyfish in Hiroshima Bay.

  9. Discards of the commercial boat seine fisheries on Posidonia oceanica beds in the eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Perica Cetinić

    2011-06-01

    Full Text Available Scientific observer records were used to estimate the retained and discarded catch composition of the commercial boat seine fisheries over Posidonia oceanica (Linnaeus Delile meadows in the eastern Adriatic, from November 2008 to December 2009. A total of 91 fish and cephalopod species were recorded in the catches, of which 20 species were always retained, 40 were always discarded and the remaining 31 were selected depending on size (only larger specimens were retained. The most abundant species in the retained catch were Spicara smaris, Atherina hepsetus and Mullus barbatus, while Chromis chromis, Symphodus ocellatus and small specimens of Boops boops dominated the discards. An estimated 43.5% by number and 28.5% by weight of the total catch were discarded. Since the minimum landing size (MLS is regulated for only 4 out of the 15 most important species in this study, and even these regulations are only partially followed, discarding practices were generally market-driven. The retained and discarded amounts of the catch as well as the numbers of retained and discarded species showed a seasonal pattern. The catches recorded during summer/autumn were generally larger than those in winter/spring. High rates of immature specimens were observed for the most important species, which is probably related to the role of Posidonia beds as important nursery grounds.

  10. Evaluation of spatial and temporal variations of inorganic nutrient species in the eastern Aegean Sea waters.

    Science.gov (United States)

    Aydin-Onen, Sinem; Kocak, Ferah; Kucuksezgin, Filiz

    2012-12-01

    In this study, the state of the five stations' quality was assessed on the basis of determination of temporal and spatial variability of nutrients with physicochemical variables. Besides this, organic matter of sediment, secchi disc depth and suspended solids were also determined. The samples were collected seasonally from different areas such as harbor and important touristic marinas along the eastern Aegean during June 2008-2009. As a result, the nutrients ranged between NH₄: 0.10-25.6, NO₂: 0.01-1.5, NO₃: 0.19-7.0, o.PO₄: 0.17-6.8, TPO₄: 0.32-9.6 and Si: 0.30-13.8 μM, respectively. Precipitation leads to large changes in temperature, salinity, dissolved oxygen and nutrients. The highest nutrient values in this study were observed during the rainy season except o.PO₄-P and TPO₄-P. However, the physico-chemical variables have exhibited considerable temporal variations while nutrients showed spatial differences. The relatively high nutrient increase in the sampling stations coupled with surface runoff events during rainy period and pollution arising from both point and non-point sources. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Spatial and seasonal variability of pico-, nano- and microphytoplankton at the bottom seawater in the north coast of Sfax, Eastern Mediterranean Sea.

    Science.gov (United States)

    Rekik, Amira; Denis, Michel; Maalej, Sami; Ayadi, Habib

    2015-10-01

    In the frame of the Taparura Project, we studied the distribution of pico-, nano- and microphytoplankton communities in relation to environmental variables at 18 stations sampled during four coastal cruises conducted between October 2009 and July 2010 at the bottom, on the north coast of Sfax (Tunisia, Eastern Mediterranean Sea). The restoration effect on coastal ultraphytoplankton (Sfax north coast restoration achieved by the Taparura Project.

  12. The comparative statuses of the Far Eastern seas and the northwestern Pacific Ocean based on the range of integral characteristics of pelagic and bottom trawl macrofauna

    Directory of Open Access Journals (Sweden)

    Igor V. Volvenko

    2015-03-01

    Full Text Available Comparison of the pelagial and benthal of the Far Eastern seas (mainly within the borders of the Russian EEZ and the contiguous part of the Pacific Ocean according to the macrofauna population density, species richness, evenness and diversity, and average individual weight of animals, is provided on the basis of the results of multiannual broad-scale pelagic and bottom trawl surveys carried out in 1977–2010.

  13. The comparative statuses of the Far Eastern seas and the northwestern Pacific Ocean based on the range of integral characteristics of pelagic and bottom trawl macrofauna

    OpenAIRE

    Igor V. Volvenko

    2015-01-01

    Comparison of the pelagial and benthal of the Far Eastern seas (mainly within the borders of the Russian EEZ) and the contiguous part of the Pacific Ocean according to the macrofauna population density, species richness, evenness and diversity, and average individual weight of animals, is provided on the basis of the results of multiannual broad-scale pelagic and bottom trawl surveys carried out in 1977–2010.

  14. Lucinoma kazani n. sp. (Mollusca: Bivalvia): evidence of a living benthic community associated with a cold seep in the Eastern Mediterranean Sea

    Science.gov (United States)

    Salas, C.; Woodside, J.

    2002-06-01

    Lucinoma kazani, a new deep-water species of Lucinidae from the Eastern Mediterranean Basin, is described and illustrated. The material was collected in the Anaximander Mountains, between Rhodes and Cyprus, Eastern Mediterranean. The first living specimens were collected during the Dutch ANAXIPROBE project in the Kazan volcano, at a depth of 1709 m. Later, during the MEDINAUT programme, both living specimens and shells were collected from several mud volcanoes at different depths in the Anaximander Mountains. This bivalve holds symbionts in the ctenidia, as do all previously studied Lucinidae. The type of habitat of this new species is gas-saturated mud, with high levels of methane, which diffuses upwards into a low-oxygen deep-water. Therefore, we consider this as evidence of a living cold seep community in the Eastern Mediterranean Sea.

  15. Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea.

    Science.gov (United States)

    Lazar, Cassandre Sara; Parkes, R John; Cragg, Barry A; L'Haridon, Stéphane; Toffin, Laurent

    2011-08-01

    Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic methanogens could be well adapted to hypersaline environments. Hydrogenotrophic methanogenesis was the dominant pathway below 50 cm; however, low rates of acetoclastic methanogenesis were also present, even in sediment layers with the highest salinity, showing that these methanogens can thrive in this extreme environment. PCR-DGGE and methyl coenzyme M reductase gene libraries detected sequences affiliated with anaerobic methanotrophs (mainly ANME-1) as well as Methanococcoides methanogens. Results show that the hypersaline conditions in the centre of the Napoli mud volcano influence active biogenic methane fluxes and methanogenic/methylotrophic diversity. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  16. Mercury Redox Chemistry in Waters of the Eastern Asian Seas: From Polluted Coast to Clean Open Ocean.

    Science.gov (United States)

    Ci, Zhijia; Zhang, Xiaoshan; Yin, Yongguang; Chen, Jinsheng; Wang, Shiwei

    2016-03-01

    We performed incubation experiments using seawaters from representative marine environments of the eastern Asian seas to determine the mercury (Hg) available for photoreduction (Hgr(II)), to investigate the Hg redox reaction kinetics, and to explore the effect of environmental factors and water chemistry on the Hg redox chemistry. Results show that Hgr(II) accounted for a considerable fraction of total Hg (THg) (%Hgr(II)/THg: 24.90 ± 10.55%, n = 27) and positively correlated with THg. Filtration decreased the Hgr(II) pool of waters with high suspended particulate matter (SPM). The positive linear relationships were found between pseudo-first order rate constants of gross Hg(II) photoreduction (kr) and gross Hg(0) photo-oxidation (ko) with photosynthetically active radiation (PAR). Under the condition of PAR of 1 m mol m(-2) s(-1), the kr were significantly (p < 0.05) lower than ko (kr/ko: 0.86 ± 0.22). The Hg(0) dark oxidation were significantly higher than the Hg(II) dark reduction. The Hg(II) dark reduction was positively correlated to THg, and the anaerobic condition favored the Hg(II) dark reduction. Filtration significantly influenced the Hg photoredox chemistry of waters with high SPM. UVB radiation was important for both Hg(II) photoreduction and Hg(0) photo-oxidation, and the role of other wavebands in photoinduced transformations of Hg varied with the water chemistry.

  17. Modeled connectivity between northern rock sole (Lepidopsetta polyxystra) spawning and nursery areas in the eastern Bering Sea

    Science.gov (United States)

    Cooper, D. W.; Duffy-Anderson, J. T.; Stockhausen, W. T.; Cheng, W.

    2013-11-01

    Connectivity between spawning and potential nursery areas of northern rock sole, Lepidopsetta polyxystra, in the eastern Bering Sea was examined using an individual-based biophysical-coupled model. Presumed spawning areas were identified using historical field-collected ichthyoplankton data, and nursery habitats were characterized based on previously described settlement areas. Simulated larvae were released from spawning areas near the Pribilof Islands, south of the Pribilof Islands along the outer continental shelf, on the north side of the Alaska Peninsula, and in the Gulf of Alaska south of Unimak Island. Simulated larvae were transported along two general pathways: 1) northwards along the outer continental shelf from Unimak Island towards the Pribilof Islands and further north offshore of mainland Alaska, and 2) eastward along the Alaska Peninsula. At the end of the 2-month simulation, drift pathways placed pre-settlement stage larvae offshore of known nursery areas of older juveniles near mainland Alaska, consistent with a hypothesis that initial settlement may be followed by substantial post-settlement redistribution.

  18. Absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea and the waters off eastern Taiwan

    Science.gov (United States)

    Zhou, Fengxia; Gao, Xuelu; Song, Jinming; Chen, Chen-Tung Arthur; Yuan, Huamao; Xing, Qianguo

    2018-05-01

    The absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea (ECS) and the waters off eastern Taiwan (WET) were studied during May 2014. CDOM absorption coefficient (a280) and spectral slope (S275-295) revealed considerable spatial variations. In the ECS, the values of a280 and S275-295 presented a reverse distribution pattern. In the WET, a280 values were generally low while S275-295 values were generally high. Vertical distributions of a280 and S275-295 also varied in different regions. Terrestrial input, phytoplankton production, sediment release or photobleaching may be responsible for the dynamics of CDOM. Relationships among CDOM related parameters could partly support this conclusion. a280 were also used to trace different water masses and the result showed that the influence of Changjiang Diluted Water could reach the outer shelf of the northern ECS, and that the Kuroshio Current had a strong influence on the middle shelf of the southern ECS.

  19. Seasonal and spatial variations of marine litter on the south-eastern Black Sea coast.

    Science.gov (United States)

    Terzi, Yahya; Seyhan, Kadir

    2017-07-15

    The south-eastern Black Sea coast in Turkey was evaluated for marine litter composition and density covering nine beaches during four seasons. The marine litter (>2cm in size), was collected from the coast and categorized into material and usage categories. The data analysis showed that plastic was the most abundant litter (≥61.65%) by count and weight followed by styrofoam and fabric. The marine litter density ranged from 0.03 to 0.58 with a mean (±SD) of 0.16±0.02 items/m 2 by count. Based on weight, it varied between 0.44 and 14.74g/m 2 with 3.35±1.63. The east side had a higher marine litter density than the west side with significant differences between beaches. The variations due to different seasons were not significant for any beach. The results of this study should provide baseline information about the coastal marine pollution and will assist the mitigation strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Influence of the tidal front on the three-dimensional distribution of spring phytoplankton community in the eastern Yellow Sea.

    Science.gov (United States)

    Choi, Byoung-Ju; Lee, Jung A; Choi, Jae-Sung; Park, Jong-Gyu; Lee, Sang-Ho; Yih, Wonho

    2017-04-01

    Hydrographic observation and biological samplings were conducted to assess the distribution of phytoplankton community over the sloping shelf of the eastern Yellow Sea in May 2012. The concentration of chlorophyll a was determined and phytoplankton was microscopically examined to conduct quantitative and cluster analyses. A cluster analysis of the phytoplankton species and abundance along four observation lines revealed the three-dimensional structure of the phytoplankton community distribution: the coastal group in the mixed region, the offshore upper layer group preferring stable water column, and the offshore lower layer group. The subsurface maximum of phytoplankton abundance and chlorophyll a concentration appeared as far as 64 km away from the tidal front through the middle layer intrusion. The phytoplankton abundance was high in the shore side of tidal front during the spring tide. The phytoplankton abundance was relatively high at 10-m depth in the mixed region while the concentration of chlorophyll a was high below the depth. The disparity between the profiles of the phytoplankton abundance and the chlorophyll a concentration in the mixed region was related to the depth-dependent species change accompanied by size-fraction of the phytoplankton community. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Alterations in microbial community composition with increasing fCO2: a mesocosm study in the eastern Baltic Sea

    Directory of Open Access Journals (Sweden)

    K. J. Crawfurd

    2017-08-01

    Full Text Available Ocean acidification resulting from the uptake of anthropogenic carbon dioxide (CO2 by the ocean is considered a major threat to marine ecosystems. Here we examined the effects of ocean acidification on microbial community dynamics in the eastern Baltic Sea during the summer of 2012 when inorganic nitrogen and phosphorus were strongly depleted. Large-volume in situ mesocosms were employed to mimic present, future and far future CO2 scenarios. All six groups of phytoplankton enumerated by flow cytometry ( <  20 µm cell diameter showed distinct trends in net growth and abundance with CO2 enrichment. The picoeukaryotic phytoplankton groups Pico-I and Pico-II displayed enhanced abundances, whilst Pico-III, Synechococcus and the nanoeukaryotic phytoplankton groups were negatively affected by elevated fugacity of CO2 (fCO2. Specifically, the numerically dominant eukaryote, Pico-I, demonstrated increases in gross growth rate with increasing fCO2 sufficient to double its abundance. The dynamics of the prokaryote community closely followed trends in total algal biomass despite differential effects of fCO2 on algal groups. Similarly, viral abundances corresponded to prokaryotic host population dynamics. Viral lysis and grazing were both important in controlling microbial abundances. Overall our results point to a shift, with increasing fCO2, towards a more regenerative system with production dominated by small picoeukaryotic phytoplankton.

  2. Alterations in microbial community composition with increasing fCO2: a mesocosm study in the eastern Baltic Sea

    Science.gov (United States)

    Crawfurd, Katharine J.; Alvarez-Fernandez, Santiago; Mojica, Kristina D. A.; Riebesell, Ulf; Brussaard, Corina P. D.

    2017-08-01

    Ocean acidification resulting from the uptake of anthropogenic carbon dioxide (CO2) by the ocean is considered a major threat to marine ecosystems. Here we examined the effects of ocean acidification on microbial community dynamics in the eastern Baltic Sea during the summer of 2012 when inorganic nitrogen and phosphorus were strongly depleted. Large-volume in situ mesocosms were employed to mimic present, future and far future CO2 scenarios. All six groups of phytoplankton enumerated by flow cytometry ( < 20 µm cell diameter) showed distinct trends in net growth and abundance with CO2 enrichment. The picoeukaryotic phytoplankton groups Pico-I and Pico-II displayed enhanced abundances, whilst Pico-III, Synechococcus and the nanoeukaryotic phytoplankton groups were negatively affected by elevated fugacity of CO2 (fCO2). Specifically, the numerically dominant eukaryote, Pico-I, demonstrated increases in gross growth rate with increasing fCO2 sufficient to double its abundance. The dynamics of the prokaryote community closely followed trends in total algal biomass despite differential effects of fCO2 on algal groups. Similarly, viral abundances corresponded to prokaryotic host population dynamics. Viral lysis and grazing were both important in controlling microbial abundances. Overall our results point to a shift, with increasing fCO2, towards a more regenerative system with production dominated by small picoeukaryotic phytoplankton.

  3. Patterns in connectivity and retention of simulated Tanner crab (Chionoecetes bairdi) larvae in the eastern Bering Sea

    Science.gov (United States)

    Richar, Jonathan I.; Kruse, Gordon H.; Curchitser, Enrique; Hermann, Albert J.

    2015-11-01

    The eastern Bering Sea (EBS) population of Tanner crab (Chionoecetes bairdi) has exhibited high variability in recruitment to the commercially exploited stock since the late 1970s. Concurrently, apparent shifts in crab distribution have also been observed. Larval advection patterns and associated local retention offer a potential mechanism for these observations. The Regional Ocean Modeling System (ROMS) was used to simulate larval Tanner crab advection patterns over 1978-2004 based on larval hatching sites inferred from the distributions of reproductive females sampled during annual National Marine Fisheries Service trawl surveys. Connectivity among EBS subregions was examined by comparing start and end float locations after 60 days of simulated drift. High levels of retention (>50% of floats) were observed in the majority of source subregions, and contributed significantly to the total number of endpoints in each region. Patterns in advection and resultant interregional connectivity were variable, with strongest sustained connectivity occurring along shelf, within individual domains. Increased settlement potential in the outer domain and southern middle domain after 1990 is consistent with an observed geographic shift in fishery productivity. Apparent reliance of Bristol Bay on local larval retention validates recent spatial fishery management to conserve this area as a subpopulation.

  4. Summed Probability Distribution of 14C Dates Suggests Regional Divergences in the Population Dynamics of the Jomon Period in Eastern Japan.

    Science.gov (United States)

    Crema, Enrico R; Habu, Junko; Kobayashi, Kenichi; Madella, Marco

    2016-01-01

    Recent advances in the use of summed probability distribution (SPD) of calibrated 14C dates have opened new possibilities for studying prehistoric demography. The degree of correlation between climate change and population dynamics can now be accurately quantified, and divergences in the demographic history of distinct geographic areas can be statistically assessed. Here we contribute to this research agenda by reconstructing the prehistoric population change of Jomon hunter-gatherers between 7,000 and 3,000 cal BP. We collected 1,433 14C dates from three different regions in Eastern Japan (Kanto, Aomori and Hokkaido) and established that the observed fluctuations in the SPDs were statistically significant. We also introduced a new non-parametric permutation test for comparing multiple sets of SPDs that highlights point of divergences in the population history of different geographic regions. Our analyses indicate a general rise-and-fall pattern shared by the three regions but also some key regional differences during the 6th millennium cal BP. The results confirm some of the patterns suggested by previous archaeological studies based on house and site counts but offer statistical significance and an absolute chronological framework that will enable future studies aiming to establish potential correlation with climatic changes.

  5. Summed Probability Distribution of 14C Dates Suggests Regional Divergences in the Population Dynamics of the Jomon Period in Eastern Japan.

    Directory of Open Access Journals (Sweden)

    Enrico R Crema

    Full Text Available Recent advances in the use of summed probability distribution (SPD of calibrated 14C dates have opened new possibilities for studying prehistoric demography. The degree of correlation between climate change and population dynamics can now be accurately quantified, and divergences in the demographic history of distinct geographic areas can be statistically assessed. Here we contribute to this research agenda by reconstructing the prehistoric population change of Jomon hunter-gatherers between 7,000 and 3,000 cal BP. We collected 1,433 14C dates from three different regions in Eastern Japan (Kanto, Aomori and Hokkaido and established that the observed fluctuations in the SPDs were statistically significant. We also introduced a new non-parametric permutation test for comparing multiple sets of SPDs that highlights point of divergences in the population history of different geographic regions. Our analyses indicate a general rise-and-fall pattern shared by the three regions but also some key regional differences during the 6th millennium cal BP. The results confirm some of the patterns suggested by previous archaeological studies based on house and site counts but offer statistical significance and an absolute chronological framework that will enable future studies aiming to establish potential correlation with climatic changes.

  6. Spatial distribution of sardine and anchovy early life stages along the eastern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Barbara Zorica

    2015-10-01

    Full Text Available Despite long-term investigations of the Adriatic Sea in general and extensive research on sardine and anchovy as ecologically and economically important fish species, knowledge concerning their spawning ecology, precisely their possible spawning grounds, is still incomplete. Therefore, two scientific surveys (January, July 2012 were performed, as target species spawn during different periods of the year (sardine - October to April (Sinovčić et al., 2007 and anchovy - April to September (Zorica et al., 2013. Throughout these surveys, standard vertical plankton tows were made during the daylight at 72 stations in January and 60 stations in July using a WP2 sampler (mouth opening, 0.255 m2; mesh size, 0.200 mm. WP2 net was put vertically down during the calm sea to a depth of 100 m or to 5 m above the seabed in relatively shallow marine area (less than 100 m. Plankton samples were preserved in 4% buffered formalin and transported to the laboratory where they were analysed. Throughout ichtyoplankton analysis of samples collected during the winter survey a total of 506 sardine eggs and 348 larvae were sorted out. The mean sardine egg and larval abundance in the analysed period at positive stations was 57.8 +/- 77.4 eggs/m2 and 29 +/- 25.85 larvae/m2, with peaks of 396 eggs/m2 and 108 larvae/m2 at positive sampling stations. Concerning the summer survey and anchovy early life stages from obtained samples 1489 anchovy eggs and 1036 larvae were isolated. Average abundance of anchovy eggs and larvae was 145.26 +/- 201.27eggs/m2 and 115.11+/- 162.32 larvae/m2, respectively. The highest values of mentioned parameters at positive stations were 800 eggs/m2 and 952 larvae/m2. According to obtained results and their processing within Ocean Data View (odv.awi.de, revile that both species during 2012 spawn above the whole continental shelf and the areas of higher early life stages abundance overlap.

  7. Combination of geological and geophysical data by database system. Example in middle eastern part of Tohoku, Japan

    International Nuclear Information System (INIS)

    Tamanyu, Shiro

    2004-01-01

    In order to clarify the situation and origin of subsurface anomalous high temperature zone in non-volcanic area, the middle eastern part of Tohoku is selected as the model field for this case study. The distribution maps of topography, geology, microseismic hypocenter, electric resistivity, Curie-point depth, and subsurface isotherms were collected and summarized as input data to the database for 2-D and 3-D visualization. After digitizing, 6 kinds of maps are correlated each other. Following three data sets resulted in good correlation sets: volcanic front and microseismic hypocenter, resistivity and microseismic hypocenter, Curie-point depth and microseismic hypocenter. The first good correlation between volcanic front and microseismic hypocenter indicates microseismicity is caused by upward migration of magma and hydrothermal fluids. The second good correlation between resistivity and microseismic hypocenter indicates the following two patterns. One is the microseismic areas on the volcanic zone where is characterized by shallow resistivity basement, and the other is the edge of inland basin where is characterized by low resistivity. The latter is interpreted as infiltrated meteoric water causes seismic activity along fault zones. The third good correlation between Curie-point depth and microseismic hypocenter indicates the cut-off depths of upper crustal seismicity, so-called brittle-plastic boundary, is almost equivalent to Curie-point depth which is presumed as around 600degC. (author)

  8. Distribution and abundance of fish larvae in the northern Ionian Sea (Eastern Mediterranean)

    Science.gov (United States)

    Granata, Antonia; Cubeta, Annaluce; Minutoli, Roberta; Bergamasco, Alessandro; Guglielmo, Letterio

    2011-09-01

    The purpose of this paper was to study the spatial distribution, abundance and composition of fish larvae in the northern Ionian Sea. Samples were collected to the 600 m depth with an electronic multinet BIONESS during the "INTERREG Italia-Grecia" oceanographic cruise carried out in March 2000 off the Apulian Italian coast. A total of 46 species of teleost early stages were collected, belonging to 38 genera and 22 families. Over 52% of the larvae identified were mesopelagic species, almost 27% were demersal and about 21% pelagic. A total of 307 myctophids, 69 clupeids and 61 gadid post-larvae dominated the community. Benthosema glaciale (mean 6.1 mm SL) was the most abundant species (21.6%), the most frequent in the samples (28.8%), and dominant in the whole study area (mean 1.4 ind/100 m3). Particular attention was given to the horizontal and vertical distribution and abundance of the three dominant post-larval species: Benthosema glaciale, Sprattus sprattus sprattus and Notoscopelus elongatus. The Pearson coefficient ( R = 0.734) showed a high correlation between total zooplankton and fish larval assemblages in terms of spatial distribution abundance values. Regarding the vertical distribution of fish larvae, Sorensen's index ( S = 0.69) showed that fish larvae and total zooplankton abundance peaks co-occurred along the water column.

  9. Trace element geochemistry of Jurassic coals from Eastern Black Sea Region, NE-Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cebi, F.H.; Korkmaz, S.; Akcay, M. [Karadeniz Technical University, Trabzon (Turkey). Dept. of Geological Engineering

    2009-07-01

    The majority of coal deposits in the world are of Carboniferous and Tertiary age but Jurassic coals are seldom present. They are also exposed in northern Turkey and occur both at the lower and upper sections of the Liassic-Dogger volcanic- and volcani-clastic series. The coals at the base of the Jurassic units are characterized by higher Ba, Th, Zr, and Cr-Ni and lower S values than those at the top of the units, indicating, in general, laterally consistent trace element contents. The vertical distribution of trace elements in individual coal seams is also rather consistent. The B contents of coals from the Godul and Norsun areas vary from 1.5 to 4.3 ppm whereas those from the Alansa area are in the range of 95 to 138 ppm. This suggests that the coals in the Godul and Norsun areas were deposited in a swamp environment inundated by the sea from time to time, whereas coals of the Alansa were deposited in a saline environment.

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

    Directory of Open Access Journals (Sweden)

    K. TSAGARAKIS

    2015-01-01

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

  11. The Rough-Toothed Dolphin, Steno bredanensis, in the Eastern Mediterranean Sea: A Relict Population?

    Science.gov (United States)

    Kerem, D; Goffman, O; Elasar, M; Hadar, N; Scheinin, A; Lewis, T

    Only recently included among the cetacean species thought to regularly occur in the Mediterranean, the rough-toothed dolphin (Steno bredanensis) is an obscure and enigmatic member of this ensemble. Preliminary genetic evidence strongly indicates an Atlantic origin, yet the Mediterranean distribution for this species is conspicuously detached from the Atlantic, with all authenticated records during the last three decades being east of the Sicilian Channel and most within the bounds of the Levantine Basin. These dolphins are apparently a small, relict population, probably the remnant of a larger one, contiguous with that in the Atlantic and nowadays entrapped in the easternmost and warmest province. Abundance data are lacking for the species in the Mediterranean. Configuring acoustic detection software to recognise the apparently idiosyncratic vocalisations of rough-toothed dolphins in past and future acoustic recordings may prove useful for potential acoustic monitoring. Evidence accumulated so far, though scant, points to seasonal occupation of shallow coastal waters. Vulnerability to entanglement in gill-nets, contaminants in the region, and the occurrence of mass strandings (possibly in response to anthropogenic noise), are major conservation concerns for the population in the Mediterranean Sea. © 2016 Elsevier Ltd. All rights reserved.

  12. Impacts of two super typhoons on the Kuroshio and marginal seas on the Pacific coast of Japan

    Science.gov (United States)

    Tada, Hiroaki; Uchiyama, Yusuke; Masunaga, Eiji

    2018-02-01

    High-resolution downscaling ocean modeling was conducted to investigate the impacts of two super typhoons on the Kuroshio in the fall of 2014 off the Kyushu and Shikoku Islands, Japan. The model result was compared with field observations and satellite altimetry. The synoptic and mesoscale oceanic structures around the Kuroshio exhibit a good reproducibility. The typhoons generated near-inertial oscillations (NIOs) and near-inertial internal waves (NIIWs) around the Kuroshio path, particularly on the right side of the typhoon tracks. The NIOs developed in the mixed layer to alter the direction of the Kuroshio by 30°. The associated velocity off the Shikoku and Kyushu Islands was significantly decelerated by 0.2 ms-1. The velocity almost vanished off Kyushu Island and thus induced an unstable fluctuating path shortly after both typhoons passed over that region. The NIIWs were also excited at the thermocline, resulting in the oscillation of the Kuroshio path occurred in the entire water column. In contrast, off Shikoku Island, the typhoons shifted the Kuroshio path northward to enhance the interactions with the topographies. This shift caused considerable eddy shedding from the capes that resulted in mesoscale counterclockwise circulations as cyclonic quasi-standing eddies with a shedding period of 3 days in the north of the Kuroshio path. The magnitude, direction, and meridional location of the path of the Kuroshio prominently fluctuated with the propagation of these eddies, manifested off Shikoku Island. Furthermore, these eddies induced sporadic northward intrusions of the Kuroshio warm water through the Kii Channel into the Seto Inland Sea (SIS), where a weak but persisting southward outflow prevails under normal conditions. Therefore, the process could collectively be called the "typhoon-Kuroshio-eddy interaction", which conceptually differs from the "typhoon-eddy-Kuroshio interaction" in the previous studies, where the Kuroshio was modulated by eddy collision

  13. Estimation of past sea-level variations based on ground-penetrating radar mapping of beach-ridges - preliminary results from Feddet, Faxe Bay, eastern Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Nielsen, Lars; Clemmensen, Lars B

    2011-01-01

    been chosen as a key-locality in this project, as it is located relatively close to the current 0-isobase of isostatic rebound. GPR reflection data have been acquired with shielded 250 MHz Sensors & software antennae along a number of profile lines across beach ridge and swale structures of the Feddet...... isostatic uplift and changes in eustatic sea-level, and therefore represent an archive of past relative sea-level variations. Here, we present preliminary results from investigation of beach ridges from Feddet, a small peninsula located in Faxe Bay (Baltic Sea) in the eastern part of Denmark. Feddet has...... peninsula. Furthermore, topography along the profile lines, primary on beach ridge summits and swale bases, was measured to be included in the interpretation of the GPR reflection data using a high-resolution GPS system. The topography-corrected GPR data allow us to interpret internal sedimentary...

  14. Radiological significance of coal, slag and fly ash samples from the Eastern Black Sea region

    Energy Technology Data Exchange (ETDEWEB)

    Damla, Nevzat [Batman Univ. (Turkey). Dept. of Physics; Cevik, Ugur [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Physics; Kara, Ayhan [Osmaniye Korkut Ata Univ. (Turkey). Dept. of Physics

    2012-11-15

    This work presents a study of natural radioactivity levels in coal and its combustion residues (fly ash and slag) used in the houses in Black Sea Region, Turkey. Coal, fly ash and slag samples were provided from different locations of the region and analyzed by gamma spectroscopy using a high-purity germanium detector (HPGe). Also, chemical analyses of these samples were carried out using energy dispersive X-ray fluorescence spectrometer. The mean {sup 226}Ra activity concentrations in coal, slag and fly ash were measured as 83, 99 and 38 Bq kg{sup -1}, respectively. The mean {sup 232}Th activity concentrations in coal, slag and fly ash were measured as 108, 113 and 50 Bq kg{sup -1}, respectively. The mean {sup 40}K activity concentrations in coal, slag and fly ash were found to be 366, 381 and 204 Bq kg{sup -1}, respectively. The potential radiological hazards associated to these materials were evaluated by calculating the radium equivalent activity (Ra{sub eq}), the air absorbed gamma dose rate (D), the annual effective dose rate (AED), the external hazard index (H{sub ex}) and internal hazard index (H{sub in}) and compared with the internationally accepted or reference values. The mean Ra{sub eq} values of the coal, fly ash and slag samples were lower than the recommended maximum values 370 Bq kg{sup -1} by the Organization for Economic Cooperation and Development (OECD). The overall mean outdoor terrestrial gamma air absorbed dose rate in coal, fly ash and slag samples are 119, 129 and 62 nGy h{sup -1} and the corresponding outdoor annual effective doses are 0.60, 0.32 and 0.64 mSv y{sup -1}, which is higher than the worldwide average (0.07 mSv y{sup -1}), respectively. Moreover, the enrichment factors relative to the input coal are calculated for the radionuclide contents observed. Calculated enrichment factor values for {sup 226}Ra and {sup 232}Th were found 1.14 and 1.01, respectively. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Maria Corsini-Foka

    2015-11-01

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

  16. Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles

    International Nuclear Information System (INIS)

    Takahashi, Shin; Oshihoi, Tomoko; Ramu, Karri; Isobe, Tomohiko; Ohmori, Koji; Kubodera, Tsunemi; Tanabe, Shinsuke

    2010-01-01

    Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between δ 15 N ( per mille ) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in δ 13 C ( per mille ) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.

  17. Aspects on gametogenesis, fertilization and embryogenesis of two deep-sea polychaetes from Eastern Atlantic cold seeps

    Science.gov (United States)

    Gaudron, S. M.; Hourdez, S.; Olu, K.

    2017-11-01

    We investigated two gonochoristic species of annelid polychaetes (one siboglinid and one polynoid) from cold seeps that ranged from 525 m to 3300 m in depth (Guiness, Worm Hole and Regab pockmarks) on the Gabon and Congo continental margins (Gulf of Guinea). Different aspects of gametogenesis (oocyte diameter, presence of ovisac, spermatozoa shape, and fecundity), fertilization (in vitro fertilization experiments: IVF) and embryogenesis (cleavage rate) were studied. The sampled siboglinid was a new species of Lamellibrachia and the second population of this genus in the Eastern Atlantic. Mean oocyte diameter was about 100 μm and fully-grown primary oocytes were stored in an ovisac, as in other studied siboglinids. The presence of a single spermatozoon was noted within an oviduct, indicating a possible internal fertilization. The rate of cell division at 6 °C was one cleavage every 20 h. Embryos developed normally to the blastula stage after 5-d post-fertilization at atmospheric pressure suggesting some pressure tolerance. The second polychaete was the scale-worm Branchipolynoe cf. seepensis that lives in commensalism in the mantle cavity of Bathymodiolus aff. boomerang. Anatomical reproductive features were similar to those described in B. seepensis from hydrothermal vents on Mid-Atlantic Ridge, with lecithotrophic larval development and continuous gametogenesis. We performed the first IVF carried out on gametes for any deep-sea polynoid species. Fertilization and development occurred but a number of abnormalities were observed demonstrating a limitation to embryogenesis at atmospheric pressure. The rate of cell division was three times faster at 8 °C than at 4 °C with a maximum stage of 8-cells reached after 72 h post-fertilization. We surprisingly observed some oocytes from the negative seawater control during IVF experiments cleaved to the 2-cell stage, demonstrating the possible occurrence of internal fertilization prior to IVF experiment or the accidental

  18. Reprint of - Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

    Science.gov (United States)

    Ross, Steve W.; Rhode, Mike; Brooke, Sandra

    2017-09-01

    Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in region warrants additional studies to better understand the influences of oceanography and geology on the occurrence of DSC and associated organisms. Protection measures are being considered to ensure the long-term integrity of this diverse ecosystem.

  19. Updated analysis of flatfish recruitment response to climate variability and ocean conditions in the Eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, Thomas; Stockhausen, William; Bond, Nicholas

    2013-10-01

    This study provides a retrospective analysis of the relationship between physical oceanography, biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole (Hippoglossoides elassodon), northern rock sole (Lepidopsetta polyxystra), and arrowtooth flounder (Atheresthes stomias) during the period 1978-2005. Stock assessment model estimates of recruitment and spawning stock size indicate that temporal patterns in productivity are consistent with decadal scale (or shorter) patterns in climate variability, which may influence marine survival during the early life history phases. Density-dependence (through spawning stock size) was statistically significant in a Ricker stock-recruit model of flatfish recruitment that included environmental terms. Wind-driven advection of northern rock sole and flathead sole larvae to favorable nursery grounds was found to coincide with years of above-average recruitment. Ocean forcing of Bristol Bay surface waters during springtime was mostly on-shelf (eastward) during the 1980s and again in the early 2000s, but was off-shelf (westerly) during the 1990s, corresponding with periods of good and poor recruitment, respectively. Finally, the Arctic Oscillation was found to be an important indicator of arrowtooth flounder productivity. Model results were applied to IPCC (Intergovernmental Panel on Climate Change) future springtime wind scenarios to predict the future impact of climate on northern rock sole productivity and indicated that a moderate future increase in recruitment might be expected because the climate trends favor on-shelf transport but that density-dependence will dampen this effect such that northern rock sole abundance will not be substantially affected by climate change.

  20. Contrasting reproductive strategies in three deep-sea octocorals from eastern Canada: Primnoa resedaeformis, Keratoisis ornata, and Anthomastus grandiflorus

    Science.gov (United States)

    Mercier, A.; Hamel, J.-F.

    2011-06-01

    Various aspects of reproduction were studied in three deep-sea octocorals belonging to the order Alcyonacea that co-occur at bathyal depths on the continental edge and the slope of eastern Canada. The main goals were to expand knowledge of deep-water heterotrophic corals and ascertain whether reproductive strategies could explain the known patterns of occurrence. Anthomastus grandiflorus is a gonochoric species with a female-biased sex ratio that exhibits internal fertilization and brooding of planula larvae. Conversely, Primnoa resedaeformis and Keratoisis ornata rely on broadcast spawning and external fertilization; their sexuality remains undetermined as spermatocysts were not found. In P. resedaeformis, the presence of mixed size classes of oocytes in samples from all months, depths, and locations studied suggests continuous oogenesis or overlapping development of oocyte cohorts, indicative of a gametogenic cycle spanning more than a year. No evidence of periodicity was found in this species, although it could have been masked by the striking bathymetric variation in potential relative fecundity (oocytes polyp-1). The two other octocorals displayed a clear annual breeding pattern. Spawning in K. ornata and larval release in A. grandiflorus occurred in late summer and fall, respectively, possibly in response to environmental factors, as supported by shifts in the reproductive peak of A. grandiflorus across latitudes. The three species are presumed to share a nonfeeding larval mode, and data on their reproductive potential do not present any striking disparities. Published data on bycatches and video surveys in Atlantic Canada indicate that the gonochoric brooder A. grandiflorus is more widely distributed than the two free spawners, P. resedaeformis and K. ornata, which is contrary to common dispersal potential paradigms.

  1. Key drivers controlling stable isotope variations in daily precipitation of Costa Rica: Caribbean Sea versus Eastern Pacific Ocean moisture sources

    Science.gov (United States)

    Sánchez-Murillo, R.; Birkel, C.; Welsh, K.; Esquivel-Hernández, G.; Corrales-Salazar, J.; Boll, J.; Brooks, E.; Roupsard, O.; Sáenz-Rosales, O.; Katchan, I.; Arce-Mesén, R.; Soulsby, C.; Araguás-Araguás, L. J.

    2016-01-01

    Costa Rica is located on the Central American Isthmus, which receives moisture inputs directly from the Caribbean Sea and the Eastern Pacific Ocean. This location includes unique mountainous and lowland microclimates, but only limited knowledge exists about the impact of relief and regional atmospheric circulation patterns on precipitation origin, transport, and isotopic composition. Therefore, the main scope of this project is to identify the key drivers controlling stable isotope variations in daily-scale precipitation of Costa Rica. The monitoring sites comprise three strategic locations across Costa Rica: Heredia (Central Valley), Turrialba (Caribbean slope), and Caño Seco (South Pacific slope). Sporadic dry season rain is mostly related to isolated enriched events ranging from -5.8‰ to -0.9‰ δ18O. By mid-May, the Intertropical Convergence Zone reaches Costa Rica resulting in a notable depletion in isotope ratios (up to -18.5‰ δ18O). HYSPLIT air mass back trajectories indicate the strong influence on the origin and transport of precipitation of three main moisture transport mechanisms, the Caribbean Low Level Jet, the Colombian Low Level Jet, and localized convection events. Multiple linear regression models constructed based on Random Forests of surface meteorological information and atmospheric sounding profiles suggest that lifted condensation level and surface relative humidity are the main factors controlling isotopic variations. These findings diverge from the recognized 'amount effect' in monthly composite samples across the tropics. Understanding of stable isotope dynamics in tropical precipitation can be used to a) enhance groundwater modeling efforts in ungauged basins where scarcity of long-term monitoring data drastically limit current and future water resources management, b) improve the re-construction of paleoclimatic records in the Central American land bridge, c) calibrate and validate regional circulation models.

  2. Estimation of past sea-level variations based on ground-penetrating radar mapping of beach ridges - preliminary results from Feddet, Faxe Bay, eastern Denmark

    Science.gov (United States)

    Hede, M. U.; Nielsen, L.; Clemmensen, L. B.; Noe-Nygaard, N.

    2011-12-01

    Estimates of past sea-level variations based on different methods and techniques have been presented in a range of studies, including interpretation of beach ridge characteristics. In Denmark, Holocene beach ridge plains have been formed during the last c. 7700 years, a period characterised by both isostatic uplift and changes in eustatic sea-level, and therefore represent an archive of past relative sea-level variations. Here, we present preliminary results from investigation of beach ridges from Feddet, a small peninsula located in Faxe Bay (Baltic Sea) in the eastern part of Denmark. Feddet has been chosen as a key-locality in this project, as it is located relatively close to the current 0-isobase of isostatic rebound. GPR reflection data have been acquired with shielded 250 MHz Sensors & Software antennae along a number of profile lines across beach ridge and swale structures of the Feddet peninsula. Furthermore, topography along the profile lines, primary on beach ridge summits and swale bases, was measured to be included in the interpretation of the GPR reflection data using a high-resolution GPS system. The topography-corrected GPR data allow us to interpret internal sedimentary architecture which may be used as a proxy of past relative sea-level. High-resolution GPR images with a vertical resolution of c. 0.1 m of the near-surface sediments resolve downlapping reflections along the GPR profiles, which are interpreted to mark the transition from the beach to the upper shoreface regime (i.e. sea-level) at the time of deposition. Combining the variations in height of the downlaps (in meters above present mean sea-level) with optically stimulated luminescence dating techniques provides estimates of relative sea-level at specific times.

  3. Morphological and light-absorption characteristics of individual BC particles collected in an urban seaside area at Tokaimura, eastern central Japan

    International Nuclear Information System (INIS)

    Fu Fengfu; Watanabe, Kazuo; Shinohara, Nobuo; Xu Xueqin; Xu Liangjun; Akagi, Tasuku

    2008-01-01

    To observe surface morphology and light-absorption property of different black carbon (BC) particles, different-sized aerosols were collected in Tokaimura (36.27 o N, 140.36 o E), an urban seaside area of eastern central Japan, using a high-volume Andersen type sampler during a whole year (Jan. to Dec. in 2004). The morphology of individual BC particle separated from different-sized aerosols was observed with Scanning Electron Microscope with Energy Dispersive X-ray Spectrometer (SEM-EDX) and four types of morphology were observed: 50 nm spherical particles, micrometer-sized plates with homogeneous surfaces, micrometer-sized spherical particles with homogeneous surfaces and micrometer-sized spherical particles with small holes on surfaces. The light-absorption property of BC particles with different morphology has been determined by infrared spectrometry (IRS) with a photoacoustic technique in a region of 400-4000 wavenumbers (cm -1 ). All morphology BC particles showed a strong light-absorption during 500-3000 wavenumbers (cm -1 ) with two strong broad peaks in 750-1100 and 1200-2200 wavenumbers (cm -1 ), implying that all morphology BC particles can absorb a significant part of thermal infrared emitted from the earth (wavelength 4000-50,000 nm). The seasonal variation and the size-distribution of aerosols and its chemical components (e.g. C, Na, Cl, NH 4 + , NO 3 - , SO 4 2- , Al, Ca, Mg and Fe) were also measured in this study. More than 55% of non-inorganic carbon (OC + BC) in the atmosphere was detected in the aerosols with a size smaller than 1.1 μm and the concentration of non-inorganic carbon in the atmosphere showed only a faint variation during a whole year, although the concentrations of total aerosols and its chemical components exhibited a distinct variation

  4. Morphological and light-absorption characteristics of individual BC particles collected in an urban seaside area at Tokaimura, eastern central Japan.

    Science.gov (United States)

    Fu, Feng Fu; Watanabe, Kazuo; Shinohara, Nobuo; Xu, Xueqin; Xu, Liangjun; Akagi, Tasuku

    2008-04-15

    To observe surface morphology and light-absorption property of different black carbon (BC) particles, different-sized aerosols were collected in Tokaimura (36.27 degrees N, 140.36 degrees E), an urban seaside area of eastern central Japan, using a high-volume Andersen type sampler during a whole year (Jan. to Dec. in 2004). The morphology of individual BC particle separated from different-sized aerosols was observed with Scanning Electron Microscope with Energy Dispersive X-ray Spectrometer (SEM-EDX) and four types of morphology were observed: 50 nm spherical particles, micrometer-sized plates with homogeneous surfaces, micrometer-sized spherical particles with homogeneous surfaces and micrometer-sized spherical particles with small holes on surfaces. The light-absorption property of BC particles with different morphology has been determined by infrared spectrometry (IRS) with a photoacoustic technique in a region of 400-4000 wavenumbers (cm(-1)). All morphology BC particles showed a strong light-absorption during 500-3000 wavenumbers (cm(-1)) with two strong broad peaks in 750-1100 and 1200-2200 wavenumbers (cm(-1)), implying that all morphology BC particles can absorb a significant part of thermal infrared emitted from the earth (wavelength 4000-50,000 nm). The seasonal variation and the size-distribution of aerosols and its chemical components (e.g. C, Na, Cl, NH(4)(+), NO(3)(-), SO(4)(2-), Al, Ca, Mg and Fe) were also measured in this study. More than 55% of non-inorganic carbon (OC+BC) in the atmosphere was detected in the aerosols with a size smaller than 1.1 microm and the concentration of non-inorganic carbon in the atmosphere showed only a faint variation during a whole year, although the concentrations of total aerosols and its chemical components exhibited a distinct variation.

  5. Notes on holotypes of hermit crabs (Decapoda: Anomura: Paguroidea) deposited in the collection of Zoological Museum of RAS (Saint-Petersburg, Russia) with remarks on hermit crab diversity along the Russian coast of the Sea of Japan.

    Science.gov (United States)

    Marin, Ivan

    2016-04-20

    The holotype of Clibanarius sachalinicus Kobjakova, 1955 and Clibanarius hirsutimanus Kobjakova, 1971 in the collection of Zoological Institute of Russian Academy of Sciences (Saint-Petersburg, Russia) are examined. As a result, Clibanarius hirsutimanus Kobjakova, 1971 is found to be a species of Areopaguristes nigroapiculus (Komai, 2009) while Clibanarius sachalinicus Kobjakova, 1955 is a species of Clibanarius virescens (Krauss, 1843). Remarks on a single record of Diogenes penicillatus Stimpson, 1858 from Shamora Bay (Usury Bay) of the Sea of Japan as well as current faunal list of hermit crabs from the Russian coasts of the Sea of Japan are also presented in the paper.

  6. Seismicity of the Earth 1900-2007, Japan and Vicinity

    Science.gov (United States)

    Rhea, Susan; Tarr, Arthur C.; Hayes, Gavin P.; Villaseñor, Antonio; Benz, Harley

    2010-01-01

    This map shows details of Japan and vicinity not visible in an earlier publication, U.S. Geological Survey Scientific Investigations Map 3064. Japan and its island possessions lie across four major tectonic plates: Pacific plate, North America plate; Eurasia plate; and Philippine Sea plate. The Pacific plate is subducted into the mantle, beneath Hokkaido and northern Honshu, along the eastern margin of the Okhotsk microplate, a proposed subdivision of the North America plate (Bird, 2003). Farther south, the pacific plate is subducted beneath volcanic islands along the eastern margin of the Philippine Sea plate. This 2,200 km-long zone of subduction of the Pacific plate is responsible for the creation of the deep offshore Ogasawara and Japan trenches as well as parallel chains of islands and volcanoes, typical of the Circumpacific island arcs. Similarly, the Philippine Sea plate is itself subducting under the Eurasia plate along a zone, extending from Taiwan to southern Honshu, that comprises the Ryuku Islands and the Nansei-Shonto trench.

  7. Tsunami simulations for plausible mega-thrust events originating along the Hellenic Arc and Cyprian Arc in the Eastern Mediterranean Sea

    Science.gov (United States)

    Valle, B. L.; Kalligeris, N.; Okal, E.; Findikakis, A. N.; Synolakis, C. E.

    2012-12-01

    Tsunamis have been reported at rates of one to two per year in the Mediterranean Sea, on average, over the past 2000 years. The Eastern Mediterranean region is an outstanding natural laboratory as tectonic motions are varied and have a relatively well-documented history as compared with other zones of similar seismicity (Ambraseys and Synolakis, 2010). While a variety of source materials are available, quantification of the tsunami hazards in the Eastern Mediterranean region remains vexing, as large events are infrequent. We performed tsunami simulations for a series of seismic events originating along the Hellenic Arc and Western Cyprian Arc. The locations and characteristics of the sources represent plausible mega-thrust events (>M8) similar to the 365 AD and 1303 AD events along the Hellenic Arc and potential future events along the Western Cyprian Arc. In our hydrodynamic simulations, we used a series of codes known as the Method of Splitting Tsunami (MOST) (Titov and Synolakis, 1998). Here, we report results for wave propagation in the Eastern Mediterranean and tsunami inundation along neighboring coastlines. References: Ambraseys, N. and C.E. Synolakis (2010), 'Tsunami Catalogs for the Eastern Mediterranean, Revisited,' Journal of Earthquake Engineering 14(3): 309-330; and Titov V.V. and C.E. Synolakis (1998), 'Numerical modeling of tidal wave runup,' J. Waterw. Port Coast. Ocean Eng. 124(4): 157-171.

  8. Fluctuations in the East Asian monsoon recorded by pollen assemblages in sediments from the Japan Sea off the southwestern coast of Hokkaido, Japan, from 4.3 Ma to the present

    Science.gov (United States)

    Igarashi, Yaeko; Irino, Tomohisa; Sawada, Ken; Song, Lu; Furota, Satoshi

    2018-04-01

    We reconstructed fluctuations in the East Asian monsoon and vegetation in the Japan Sea region since the middle Pliocene based on pollen data obtained from sediments collected by the Integrated Ocean Drilling Program off the southwestern coast of northern Japan. Taxodiaceae conifers Metasequoia and Cryptomeria and Sciadopityacere conifer Sciadopitys are excellent indicators of a humid climate during the monsoon. The pollen temperature index (Tp) can be used as a proxy for relative air temperature. Based on changes in vegetation and reconstructed climate over a period of 4.3 Ma, we classified the sediment sequence into six pollen zones. From 4.3 to 3.8 Ma (Zone 1), the climate fluctuated between cool/moist and warm/moist climatic conditions. Vegetation changed between warm temperate mixed forest and cool temperate conifer forest. The Neogene type tree Carya recovered under a warm/moist climate. The period from 3.8 to 2.5 Ma (Zone 2) was characterized by increased Metasequoia pollen concentration. Warm temperate mixed forest vegetation developed under a cool/moist climate. The period from 2.5 to 2.2 Ma (Zone 3) was characterized by an abrupt increase in Metasequoia and/or Cryptomeria pollen and a decrease in warm broadleaf tree pollen, indicating a cool/humid climate. The Zone 4 period (2.2-1.7 Ma) was characterized by a decrease in Metasequoia and/or Cryptomeria pollen and an increase in cool temperate conifer Picea and Tsuga pollen, indicating a cool/moist climate. The period from 1.7 to 0.3 Ma (Zone 5) was characterized by orbital-scale climate fluctuations. Cycles of abrupt increases and decreases in Cryptomeria and Picea pollen and in Tp values indicated changes between warm/humid and cold/dry climates. The alpine fern Selaginella selaginoides appeared as of 1.6 Ma. Vegetation alternated among warm mixed, cool mixed, and cool temperate conifer forests. Zone 6 (0.3 Ma to present) was characterized by a decrease in Cryptomeria pollen. The warm temperate broadleaf

  9. Biological parameters and feeding behaviour of invasive whelk Rapana venosa Valenciennes, 1846 in the south-eastern Black Sea of Turkey

    Directory of Open Access Journals (Sweden)

    Hacer Saglam

    2014-06-01

    Full Text Available Objective: To determine length-weight relationships, growth type and feeding behavior of the benthic predator Rapa whelk at the coast of Camburnu, south-eastern Black Sea. Methods: Rapa whelk was monthly collected by dredge sampling on the south-eastern Black Sea at 20 m depth. The relationships between morphometric parameters of Rapa whelk were described by linear and exponential models. The allometric growth of each variable relative to shell length (SL was calculated from the function Y=aSLb or logY=loga+blogSL. The functional regression b values were tested by t-test at the 0.05 significance level if it was significantly different from isometric growth. The total time spent on feeding either on mussel tissue or live mussels was recorded for each individual under controlled conditions in laboratory. Results: The length-weight relationships showed positive allometric growth and no inter-sex variability. Body size in the male population was significantly higher than in the individuals of the female. All characters in males and females showed a trend towards allometry rather than isometry. While the total time spent feeding increased with increasing prey size the total time that Rapana venosa spent feeding decreased with increasing Rapa whelk size. The total average feeding time needed by Rapa whelks was 160 min. But they took 310 min on live mussels in 27-28 °C in the laboratory conditions. Conclusions: Length and weight relationships, growth type, total time spent feeding of this species were explained in details for this region. It would be useful to sustainable management in the south-eastern Black Sea of Turkey. The results about the feeding behaviour of this species will contribute to the understanding of the role of this species within the ecosystem.

  10. Neogene Tectonics of Part of the Junction of Cyprus and Hellenic Arcs in the Eastern Mediterranean Sea

    Science.gov (United States)

    Küçük, H. M.; Dondurur, D.; ćifçi, G.; Gürçay, S.; Hall, J.; Yaltırak, C.; Aksu, A. E.

    2012-04-01

    the Finike Basin is puzzling and requires that the Finike Basin either remained above the depositional surface during the Messinian or was isolated from the eastern Mediterranean Sea.

  11. Paleo-coastline of the Central Eastern Adriatic Sea, and Paleo-Channels of the Cetina and Neretva rivers during the last glacial maximum

    OpenAIRE

    SIKORA, Marjan; MIHANOVIĆ, Hrvoje; VILIBIĆ, Ivica

    2014-01-01

    he paper documents the use of a Digital Elevation Model (DEM) method to reconstruct paleo-channels and the paleo-coastline during the Last Glacial Maximum (LGM) in the Central Eastern Adriatic area. We focused on the paleo-coastline and paleo-channels of the Neretva and the Cetina rivers, which were estimated from the 15’’ bathymetry available for the Adriatic Sea. While being aware of the limitations of the method and the resolution of the bathymetry grid, we successfully reproduced th...

  12. Modelling habitat range and seasonality of a new, non-indigenous polychaete Laonome sp (Sabellida, Sabellidae) in Parnu Bay, the north-eastern Baltic Sea

    OpenAIRE

    Kotta, Jonne; Kotta, Ilmar; Bick, Andreas; Bastrop, Ralf; Väinölä, Risto

    2015-01-01

    An as-yet-undescribed, non-indigenous polychaete species was found at very high densities in the eastern part of the Baltic Sea in Estonia in 2012. The species belongs to the sabellid genus Laonome Malmgren, 1866, but it could not be assigned to any of the previously described species. To date, the species has established a stable population after surviving a notably cold winter (2012/2013). To study the local distribution and abundance of the species, a spatial grid with some stations repeat...

  13. Applicability of the Decision Matrix of North Eastern Atlantic, Mediterranean and connected seas Tsunami Warning System to the Italian tsunamis

    Directory of Open Access Journals (Sweden)

    S. Tinti

    2012-03-01

    Full Text Available After the 2004 Indian Ocean tsunami catastrophe, UNESCO through the IOC (Intergovernmental Oceanographic Commission sponsored the establishment of Intergovernmental Coordination Groups (ICG with the aim to devise and implement Tsunami Warning Systems (TWSs in all the oceans exposed to tsunamis, in addition to the one already in operation in the Pacific (PTWS. In this context, since 2005, efforts have begun for the establishment of TWSs in the Indian Ocean (IOTWS, in the Caribbean area (CARIBE EWS and in the North Eastern Atlantic, the Mediterranean and Connected Seas (NEAMTWS.

    In this paper, we focus on a specific tool that was first introduced in the PTWS routine operations, i.e., the Decision Matrix (DM. This is an easy-to-use table establishing a link between the main parameters of an earthquake and the possible ensuing tsunami in order to make quick decision on the type of alert bulletins that a Tsunami Warning Center launches to its recipients. In the process of implementation of a regional TWS for the NEAM area, two distinct DMs were recently proposed by the ICG/NEAMTWS, one for the Atlantic and the other for the entire Mediterranean area.

    This work applies the Mediterranean NEAMTWS DM to the earthquakes recorded in Italy and compares the action predicted by the DM vs. the action that should be appropriate in view of the observed tsunami characteristics with the aim to establish how good the performance of the Italian TWS will be when it uses the DM for future events. To this purpose, we make use of the parametric catalogue of the Italian earthquakes (CPTI04 compiled in 2004 and the most recent compilation of the Italian tsunami, based on the Italian Tsunami Catalogue of 2004 and the subsequent revisions. In order to better compare the TWS actions, we have identified four different kinds of action coding them from 0 to 3 according to the tsunami severity and have further considered three different distance ranges where

  14. Eastern Baltic Sea Region

    DEFF Research Database (Denmark)

    Jakobsen, Johnny Grandjean Gøgsig

    2016-01-01

    Kort over den østlige Østersøregion i middelalderen med angivelse af lokaliteter omtalt i antologien, placeret på s.8 i bogen "Church and Belief in the Middle Ages", red. Kirsi Salonen & Sari Katajala-Peltomaa (Amsterdam, 2016)....

  15. Early-to-middle Holocene sea-level fluctuations, coastal progradation and the Neolithic occupations in Yaojiang valley of southern Hangzhou bay, eastern China

    Science.gov (United States)

    Liu, Y.; Sun, Q.; Fan, D.; Chen, Z.

    2017-12-01

    The formation of Holocene coast in eastern China provided material base for the development of Neolithic civilizations. The coastal Yaojiang valley of south Hangzhou bay was one of the examples where the well-known Neolithic Hemudu Culture (HC) of Eastern China initiated. Here, we studied the early-to-middle Holocene environment changes in relation to sea-level fluctuations on the basis of a serial of sediment cores based on a set of new Accelerator Mass Spectrometry radiocarbon (AMS 14C) chronology. The result indicated that relative sea-level rose rapidly in the Yaojiang valley at the early Holocene, reaching its maximum at ca. 8000-7800 cal yr BP and then decelerated at ca. 7800-7500 cal yr BP. The alluvial plain in Yaojiang valley began to form at the foothills first and then grew towards the valley center accompanying with the sea-level stabilization after ca. 7500 cal yr BP. This progressive progradation of alluvial plain would attract the early arrivals of foragers to dwell at the foothills to engaging in rice farming after ca.7000 cal yr BP and starting the epic Hemudu Culture. The HC people then move down to the valley center as more land became available thanks to sediment aggregation and progradation. The rise and development of HC were closely associated with the sea-level induced landscape changes in Yaojiang valley at the early-middle Holocene, and the unstable hydraulic condition in the valley after 5000 cal yr BP could be accountable for the cultural termination.

  16. Status of (137)Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident.

    Science.gov (United States)

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ((134)Cs and (137)Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct (137)Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, (137)Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed (137)Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow (137)Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported (137)Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of (137)Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of (137)Cs, i

  17. Enneophyllus ecarina, a new species of scaphopod shell dwelling hermit crab (Crustacea: Decapoda: Anomura: Paguridae) from deep-sea off the Ryukyu Islands, southern Japan.

    Science.gov (United States)

    Komai, Tomoyuki

    2017-05-24

    A second species of the pagurid genus Enneophyllus McLaughlin, 1997, E. ecarina n. sp., is described and illustrated on the basis of two specimens collected from the upper bathyal depths off Amami-ohshima Island, Ryukyu Islands, southern Japan. The new species is immediately distinguished from the sole known congener, E. spinirostris McLaughlin, 1997, from the Banda Sea, Indonesia, by the non-operculiform right chela and fewer ventral spiniform setae of the ambulatory dactyli. The type species of Enneophillus, E. spinirostris, was represented only by the male holotype, and examination of the female paratype of this new species enables documentation of female characteristics in the generic diagnosis. Like E. spinirostris, the new species inhabits scaphopod shells.

  18. Variability in the air–sea interaction patterns and timescales within the south-eastern Bay of Biscay, as observed by HF radar data

    Directory of Open Access Journals (Sweden)

    A. Fontán

    2013-04-01

    Full Text Available Two high-frequency (HF radar stations were installed on the coast of the south-eastern Bay of Biscay in 2009, providing high spatial and temporal resolution and large spatial coverage of currents in the area for the first time. This has made it possible to quantitatively assess the air–sea interaction patterns and timescales for the period 2009–2010. The analysis was conducted using the Barnett–Preisendorfer approach to canonical correlation analysis (CCA of reanalysis surface winds and HF radar-derived surface currents. The CCA yields two canonical patterns: the first wind–current interaction pattern corresponds to the classical Ekman drift at the sea surface, whilst the second describes an anticyclonic/cyclonic surface circulation. The results obtained demonstrate that local winds play an important role in driving the upper water circulation. The wind–current interaction timescales are mainly related to diurnal breezes and synoptic variability. In particular, the breezes force diurnal currents in waters of the continental shelf and slope of the south-eastern Bay. It is concluded that the breezes may force diurnal currents over considerably wider areas than that covered by the HF radar, considering that the northern and southern continental shelves of the Bay exhibit stronger diurnal than annual wind amplitudes.

  19. Unlocking the hydrocarbon potential of the eastern Black Sea basin. Prospectivity of middle Miocene submarine fan reservoirs by seismic sequence stratigraphy

    International Nuclear Information System (INIS)

    Gundogan, Coskun; Galip, Ozbek; Ali, Demirer

    2002-01-01

    Full text : The objective of this paper is to present present depositional characteristics and hydrocarbon prospectivity of the middle Miocene submarine basin floor fan deposits from the exploration stand point of view by using seismic data available in the offshore eastern Black Sea basin. This basin is a Tertiary trough formed as a continuation of the Mesozoic oceanic basin. The hydrocarbon potential of the basin is believed to be high in the Tertiary section because of the existence of the elements necessary for generation, migration and entrapment of hydrocarbon. A sequence stratigraphic study has been carried out by using 2-d seismic data in the Turkish portion of the eastern Black Sea basin. The objective of the study was to determine periods of major clastic sediment influxes which might lead to identify good reservoir intervals and their spatial distribution in this basin. All basic seismic sequence stratigraphic interpretation techniques and seismic facies analysis were used to identify times of these sand rich deposition periods. Sequence stratigraphy and seismic facies analysis indicate that the basinal areas of the middle Miocene sequences were dominated mainly by submarine fan complexes introduced in the lowstand stages and pelagic sediments deposited during the transgressive and highstand stages. It was proposed that Turkish portion of this basin which is one of the best frontier exploration area with its high potential left in the world, is glimpsing to those looking for good future exploration opportunities.

  20. Evaluation of genetic diversity of cultivated tea clones (Camellia sinensis (L. Kuntze in the eastern black sea coast by inter-simple sequence repeats (ISSRS

    Directory of Open Access Journals (Sweden)

    Beris Fatih S.

    2016-01-01

    Full Text Available Tea is the most globally consumed drink after spring water and an important breeding plant with high economical value in Turkey. In half a century, various kinds of tea cultivars have been bred in Turkey to improve the quality and yield of tea plants. Since tea reproduces sexually, tea fields vary in quality. Thus, determining the genetic diversity and relationship of the plants to support breeding and cultivation is important. In this study we aimed to determine the genetic diversity of tea cultivars breeding in the Eastern Black Sea coast of Turkey and the genetic relationship between them, to verify whether the qualitative morphological designations of the clones are genetically true by the ISSR markers. Herein, the genetic diversity and relationships of 18 Turkish tea cultivars were determined using 15 ISSR markers with sizes ranging from 250 to 3000 base pairs. The similarity indices among these cultivars were between 0.456 and 0.743. Based on cluster analysis using UPGMA, some of tea cultivars originating from the same geographical position were found to be clustered closely. Our data provide valuable information and a useful basis to assist selection and cloning experiments of tea cultivars and also help farmers to find elite parental clones for tea breeding in the Eastern Black Sea coast of Turkey.

  1. Is δ15N of sedimentary organic matter a good proxy for paleodenitrification in coastal waters of the eastern Arabian Sea?

    Science.gov (United States)

    Agnihotri, Rajesh; Naqvi, S. Wajih A.; Kurian, Siby; Altabet, Mark A.; Bratton, J. F.

    We compared recently published sedimentary records of δ15N from several coastal areas affected by both natural and anthropogenically produced shallow hypoxia with the objective of testing this as a proxy for denitrification in coastal settings. We examined the eastern boundary systems of continental shelves off western India and Peru, which appear to be experiencing intensification of bottom-water oxygen depletion, most likely as a consequence of intensification of eastern boundary coastal upwelling over the last few decades. In systems that are significantly affected by an enhanced inventory of nutrients from organic matter in soils due to continental erosion following colonial land clearing (e.g., Chesapeake Bay), fertilizer and wastewater runoff (e.g., western Indian shelf and Long Island Sound), the productivity increase is largely local and induced by anthropogenic activity. The western Indian shelf thus experiences a double effect, being both an upwelling zone and prone to nutrient enrichment from land. While in other regions of both natural and anthropogenic bottom-water hypoxia, sedimentary δ15N has undergone significant increases over the Anthropocene; in the eastern Arabian Sea, an opposite trend is noticed despite historical water-column measurements revealing a contemporaneous intensification of denitrification. Plausible causes are discussed here in detail, which led us to conclude that the sedimentary δ15N may not always work as a reliable proxy of denitrification in coastal regions.

  2. A reconsideration on deep sea bed disposal of high level radiological wastes. A post-Fukushima reflection on sustainable nuclear energy in Japan

    International Nuclear Information System (INIS)

    Yoshikawa, Hidekazu

    2013-01-01

    The ultimate disposal of high-level radioactive waste (HLW) is a common issue among all nuclear developing countries. However, this becomes especially a hard issue for sustainable nuclear energy in Japan after Fukushima Daiichi accident. In this paper, the difficulty of realizing underground HLW disposal in Japanese islands is first discussed from socio-political aspects. Then, revival of old idea of deep seabed disposal of HLW in Pacific Ocean is proposed as an alternative way of HLW disposal. Although this old idea had been abandoned in the past for the reason that it would violate London Convention which prohibits dumping radioactive wastes in public sea, the author will stress the merit of seabed disposal of HLW deep in Pacific Ocean not only from the view point of more safe and ultimate way of disposing HLWs (both vitrified and spent fuel) than by underground disposal, but also the emergence of new marine project by synergetic collaboration of rare-earth resource exploration from the deep sea floor in Pacific Ocean. (author)

  3. Wave hindcast studies using SWAN nested in WAVEWATCH III - comparison with measured nearshore buoy data off Karwar, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Amrutha, M.M.; SanilKumar, V.; Sandhya, K.G.; Nair, T.M.B.; Rathod, J.L.

    of SWAN. Simulated Hs using nested SWAN model shows good correlation (r=0.96) with the nearshore measured data. During high sea state (Hs>2 m), an overestimation (~19.8% for ST2 and ~21.4% for ST4) and during low sea state (Hs<1 m...

  4. Eastern Mediterranean Sea Spatial and Temporal Variability of Thermohaline Structure and Circulation Identified from Observational (T, S) Profiles

    Science.gov (United States)

    2015-12-01

    2012). 2 The Mediterranean Sea extends between the 30° and 46° north latitudes; 5°50′ west and 36° east longitudes ( Boxer , 2014). The Western...www.ancientportsantiques.com/ancient-port-structures/design-waves/] Boxer , B., 2014: Mediterranean Sea. Accessed 14 September 2015. [Available online at http

  5. Onshore-offshore seismic reflection profiling across the southern margin of the Sea of Japan: back-arc opening, shortening and active strike-slip deformation

    Science.gov (United States)

    Sato, Hiroshi; Ishiyama, Tatsuya; Kato, Naoko; Toda, Shigeru; Kawasaki, Shinji; Fujiwara, Akira; Tanaka, Yasuhisa; Abe, Susumu

    2017-04-01

    M7-class crustal earthquakes of overlying plate in subduction system have tendency to increase before megathrust earthquake events. Due to stress buildup by the upcoming Nankai Trough megathrust earthquake, SW Japan has being seismically active for last 20 years. In terms of the mitigation of earthquake and tsunami hazards, to construct seismogenic source fault models is first step for evaluating the strong ground motions and height of tsunamis. Since 2013, we performed intense seismic profiling in and around the southern part of the Sea of Japan. In 2016, a 180-km-long onshore -offshore seismic survey was carried out across the volcanic arc and back-arc basins (from Kurayoshi to the Yamato basin). Onshore section, CMP seismic reflection data were collected using four vibroseis trucks and fixed 1150 channel recorders. Offshore part we acquired the seismic reflection data using 1950 cu inch air-guns towing a 4-km-long streamer cable. We performed CMP reflection and refraction tomography analysis. Obtained seismic section portrays compressively deformed rifted continental crust and undeformed oceanic back-arc basin, reflecting the rheological features. These basic structures were formed during the opening of the Sea of Japan in early Miocene. The sub-horizontal Pliocene sediments unconformably cover the folded Miocene sediments. The opening and clock-wise rotation of SW Japan has been terminated at 15 Ma and contacted to the young Shikoku basin along the Nankai trough. Northward motion of Philippine Sea plate (PHS) and the high thermal regime in the Shikoku basin produced the strong resistance along the Nankai trough. The main shortening deformation observed in the seismic section has been formed this tectonic event. After the initiation of the subduction along the Nankai trough, the rate of shortening deformation was decreased and the folded strata were covered by sub-horizontal Pliocene sediments. The thrusting trending parallel to the arc has been continued from

  6. Living (stained) deep-sea foraminifera off Hachinohe (NE Japan, Western Pacific): environmental interplay in oxygen-depleted ecosystems

    NARCIS (Netherlands)

    Fontanier, C.; Duros, P.; Toyofuku, T.; Oguri, K.; Koho, K.A.; Buscail, R.; Grémare, A.; Radakovitch, O.; Deflandre, B.; de Nooijer, L.J.; Bichon, S.; Goubet, S.; Ivanovsky, A.; Chabaud, G.; Menniti, C.; Reichart, G.-J.; Kitazato, H.

    2014-01-01

    Live (Rose-Bengal stained) deep-sea foraminiferal faunashave been studied at five stations between 500–2000-m depthalong the NE Japanese margin (western Pacific) tounderstand how complex environmental conditions (e.g.,oxygen depletion, organic matter) control their structure(i.e., diversity,

  7. Radioactive isotopes in atmospheric aerosols over Russia and the Sea of Japan following nuclear accident at Fukushima Nr. 1 Daiichi Nuclear Power Station in March 2011.

    Science.gov (United States)

    Neroda, Andrey S; Mishukov, Vasily F; Goryachev, Vladimir A; Simonenkov, Denis V; Goncharova, Anna A

    2014-04-01

    Artificial radionuclides, such as iodine-131 ((131)I), cesium-134 ((134)Cs), and cesium-137 ((137)Cs), as well as natural isotopes of beryllium-7 ((7)Be) and potassium-40 ((40)K) have been registered in atmospheric aerosols over Vladivostok selected from 11 March to 17 June 2011. Additionally, (134)Cs and (137)Cs were detected in atmospheric aerosols over Tomsk selected from 16 March to 17 June 2011. Artificial radionuclides were also discovered in atmospheric wet depositions sampled in Vladivostok from 3 to 17 May 2011. Moreover, these radionuclides have been registered in atmospheric aerosols over the sea surface of the Sea of Japan selected from 3 to 31 May 2011 during an expedition of the "Nadezhda" sailing ship. From 18 March to 15 April, an increase in concentrations of atmospheric aerosols over Vladivostok from 108.8 to 321.5 μg/m(3) has been registered. It was accompanied by increased activity concentrations of (134)Cs, (137)Cs, and the (131)I. During the period from 18 March to 15 April, activity concentrations of (137)Cs and (134)Cs in atmospheric aerosols increased 100 times compared with the minimum detectable concentration (MDC) level and peaked in the weekly sample gathered from 8 to 15 April (145.0 and 105.3 μBq/m(3), respectively). Variability of concentrations of natural isotopes of (7)Be and (40)K was not greater than 1 order of magnitude throughout the sampling period. Maximal values of (137)Cs and (134)Cs concentrations (1,281.5 ± 141 and 384.4 ± 42.3 μBq/m(3), respectively) in Tomsk were reached in samples taken from 1 to 2 April. For the atmospheric aerosol samples from the Sea of Japan, the largest concentration of (131)I (392.3 ± 215.7 μBq/m(3)) was detected from 13 to 19 May, while all other samples had much lower concentration values. Synoptic analysis of back trajectories movement of air masses showed that the radioactive cloud came to Vladivostok from the regions of Siberia and northeastern part of China. Synoptic

  8. Changes in distributional patterns of plaice Pleuronectes platessa in the central and eastern North Sea; do declining nutrient loadings play a role?

    Science.gov (United States)

    Støttrup, Josianne G.; Munk, Peter; Kodama, Masashi; Stedmon, Colin

    2017-09-01

    Since the beginning of the 1990s, there has been a change in the relative distribution of smaller age-classes of plaice Pleuronectes platessa (age 1-3) in the North Sea. The abundances have increased in deeper, more offshore areas, while coastal abundances have been stagnant or declining. For the same time period available time series data on nutrient conditions in the coastal North Sea area show that the freshwater nitrogen loading has decreased by about 50%. While nutrient concentrations in the ambient environment have been shown to influence growth in juvenile plaice through influence on their prey, we here inspect the potential linkage between distributional changes in plaice and the decline in nutrient loading. We compare plaice observations in coastal areas in the eastern North Sea, which have experienced large changes in eutrophication, with observations for the Dogger Bank, a large sandbank in a shallow offshore area of the North Sea. The Dogger Bank, was used as a reference location assuming this area has been less influenced from coastal eutrophication but similar regional climate conditions, and here we found no changes in the abundances of juvenile plaice. The increase in the use of offshore habitats as nursery areas by juvenile plaice in the North Sea appears not related to water depth per se but driven by specific processes dominating in near-shore areas and may be related to changes in nutrient loadings. This point to the importance of separating more general depth-related factors from conditions specific for near-shore areas, such as nutrient loadings in coastal waters and export offshore. The concurrent changes in environment and in distribution of juvenile plaice may have implications for environmental and fisheries management.

  9. Effects of hydrographic variability on the spatial, seasonal and diel diving patterns of southern elephant seals in the eastern Weddell Sea.

    Directory of Open Access Journals (Sweden)

    Martin Biuw

    2010-11-01

    Full Text Available Weddell Sea hydrography and circulation is driven by influx of Circumpolar Deep Water (CDW from the Antarctic Circumpolar Current (ACC at its eastern margin. Entrainment and upwelling of this high-nutrient, oxygen-depleted water mass within the Weddell Gyre also supports the mesopelagic ecosystem within the gyre and the rich benthic community along the Antarctic shelf. We used Conductivity-Temperature-Depth Satellite Relay Data Loggers (CTD-SRDLs to examine the importance of hydrographic variability, ice cover and season on the movements and diving behavior of southern elephant seals in the eastern Weddell Sea region during their overwinter feeding trips from Bouvetøya. We developed a model describing diving depth as a function of local time of day to account for diel variation in diving behavior. Seals feeding in pelagic ice-free waters during the summer months displayed clear diel variation, with daytime dives reaching 500-1500 m and night-time targeting of the subsurface temperature and salinity maxima characteristic of CDW around 150-300 meters. This pattern was especially clear in the Weddell Cold and Warm Regimes within the gyre, occurred in the ACC, but was absent at the Dronning Maud Land shelf region where seals fed benthically. Diel variation was almost absent in pelagic feeding areas covered by winter sea ice, where seals targeted deep layers around 500-700 meters. Thus, elephant seals appear to switch between feeding strategies when moving between oceanic regimes or in response to seasonal environmental conditions. While they are on the shelf, they exploit the locally-rich benthic ecosystem, while diel patterns in pelagic waters in summer are probably a response to strong vertical migration patterns within the copepod-based pelagic food web. Behavioral flexibility that permits such switching between different feeding strategies may have important consequences regarding the potential for southern elephant seals to adapt to

  10. Effects of seasonal and interannual variability in along-shelf and cross-shelf transport on groundfish recruitment in the eastern Bering Sea

    Science.gov (United States)

    Vestfals, Cathleen D.; Ciannelli, Lorenzo; Duffy-Anderson, Janet T.; Ladd, Carol

    2014-11-01

    The Bering Sea responds rapidly to atmospheric perturbations and over the past several decades has experienced extreme variability in both its physical and biological characteristics. These changes can impact organisms that inhabit the region, particularly marine fishes, as normal current patterns to which reproductive habits are tuned can be disrupted, which, in turn, may influence recruitment and population dynamics. To understand the influence of ocean circulation on groundfish recruitment in the eastern Bering Sea, we examined transport along and across the Bering Slope derived from 23 years (1982-2004) of simulations from a Regional Ocean Modeling System (ROMS) ocean circulation model. We expected that changes in the strength and position of the Bering Slope Current (BSC) would affect recruitment in selected species (Pacific cod, walleye pollock, Greenland halibut, Pacific halibut, and arrowtooth flounder), and that circulation features along and across the shelf edge would be strongly influenced by atmospheric forcing. Variability in along-shelf transport at three transects along the path of the BSC, cross-shelf transport across the 100 and 200 m isobaths, and transport through Unimak Pass were examined. Strong seasonal and interannual variations in flow were observed, with transport typically highest during fall and winter months, coinciding with timing of spawning activity in the five species. Significant correlations were found between transport, BSC position, and groundfish recruitment. Pacific cod, in particular, benefitted from decreased along-shelf and on-shelf flow, while Pacific halibut recruitment increased in relation to increased on-shelf transport through southern canyons. The results of this study improve our understanding of variability in circulation and associated effects on groundfish recruitment in the eastern Bering Sea.

  11. δ13C and δ15N values of sediment-trap particles in the Japan and Yamato Basins and comparison with the core-top values in the East/Japan Sea

    Science.gov (United States)

    Khim, Boo-Keun; Otosaka, Shigeyoshi; Park, Kyung-Ae; Noriki, Shinichiro

    2018-01-01

    Investigation of sediment-trap deployments in the East/Japan Sea (EJS) showed that distinct seasonal variations in particulate organic carbon (POC) fluxes of intermediate-water sediment-traps clearly corresponded to changes in chlorophyll a concentrations estimated from SeaWiFS data. The prominent high POC flux periods (e.g., March) were strongly correlated with the enhanced surface-water phytoplankton blooms. Deep-water sedimenttraps exhibited similar variation patterns to intermediate-water sediment-traps. However, their total flux and POC flux were higher than those of intermediate-water sediment-traps during some months (e.g., April and May), indicating the lateral delivery of some particles to the deep-water sediment-traps. Distinct seasonal δ13C and δ15N variations in settling particles of the intermediate-water sediment-traps were observed, strongly supporting the notion of seasonal primary production. Seasonal variations in δ13C and δ15N values from the deep-water sediment-traps were similar to those of the intermediate-water sediment-traps. However, the difference in δ13C and δ15N values between the intermediate-water and the deepwater sediment-traps may be attributed to degradation of organic matter as it sank through the water column. Comparison of fluxweighted δ13C and δ15N mean values between the deep-water sediment-traps and the core-top sediments showed that strong selective loss of organic matter components (lipids) depleted in 13C and 15N occurred during sediment burial. Nonetheless, the results of our study indicate that particles in the deep-water sediment-trap deposited as surface sediments on the seafloor preserve the record of surface-water conditions, highlighting the usefulness of sedimentary δ13C and δ15N values as a paleoceanographic application in the EJS.

  12. Submarine slides, slumps and turbidites in relation to various tectonic and sedimentary processes in the Çinarcik Basin of the eastern Marmara Sea (Turkey)

    Science.gov (United States)

    Ergin, Mustafa; Sakitas, Alper; Sarikavak, Kerim; Keskin, Seref

    2013-04-01

    The main purpose of this study was to determine and understand the impacts of the climatic changes, active tectonism, slope instability and sediment mass movements in the eastern Marmara Sea (Turkey) during the Holocene. Of these, sea level changes, earth quakes, slides, slumps and turbidites were considered to be the major causes to shape the seafloor in the region. With this in mind and within a framework of a larger Project (TÜBİTAK-YDABAG 101Y071), after the major earthquake of 17 August 1999 in Kocaeli-Turkey, both sediment samples and seismic reflection profiles were obtained during the August 2000 Cruise of the Research Vessel "MTA "SİSMİK 1" at water depths between 58 and 1249 meters in the Çınarcık Basin of the eastern Marmara Sea (NW Turkey). Offshore studies covered shelf, slope and basin-floor subenvironments. Onboard, airgun and multichannel seismic reflection system was used along 7 tracklines aligned to N-S and E-W directions. At 15 sites gravity cores were deployed and from 53 to 367 cm thick core sediments were obtained. Grain size analysis, visual core descriptions, and conventional radicarbon datings were also made. To interpret seismic profiles, well-known seismic facies analysis and stratigraphic methods were applied. Fine-grained and grayish-green colored siliciclastic mud was the dominant sediment type (also called "homogenite") deposited on the floor. The coarser-grained intervals and laminations would likely suggest effects of not only turbidites from active tectonism but they can also be related to the wind-driven offshore storm deposits and river floods after heavy rain-falls. Active normal faults on the shelves, fault scarps along the slopes and negative flower structure of syntectonic sedimentation in the deep basin floor observed on the seismic profiles all must indicate the consequences of westerly extension of the North Anatolian Fault Zone in the Marmara Sea. Seismic profiles displayed sediment structures of underwater

  13. Rock-block configuration in Uppland and the Aalands-hav basin, the regional surroundings of the SKB site in Forsmark, Sea and land areas, eastern Sweden

    International Nuclear Information System (INIS)

    Beckholmen, Monica; Tiren, Sven A.

    2010-12-01

    The Forsmark SKB site lies at the west-northwest trending shoreline in northern Uppland, sheltered from the sea by one of the larger islands in the Uppland archipelago, Graesoe. To assess the structures around Forsmark also in the sea area, the bottom structures of the Aalands-hav basin were investigated by means of depth readings from sea charts. Two rock-block maps with rock blocks at different scales were constructed and analysed for their top surface elevation. The topography in Uppland is more broken in the sea area east and northeast of Forsmark than it is on land. The major structure in the Aalands-hav basin is a westnorth- westerly line that passes southwest of Aaland, with a very steep gradient from the Aaland archipelago down to an exceptionally low sea-floor valley. On its southern side it rises in steps to a low flat basin divided into a deeper western half and a somewhat shallower eastern half. The deep west-north-westerly zone can be traced on-land past Oeregrund and Forsmark. West of Oeregrund however, the main trough swings into a north-northwesterly direction, just west of Graesoe. The southern border south of Oeregrund and Forsmark, shows a major drop in elevation northern side down. Forsmark thus lies on a ribbon with lower ground on both its southern and northern boundaries. This west-north-westerly belt is cut in two by a major north-south lineament that cuts through the archipelago between Aaland and Graesoe with a very deep canyon. This structure was seismically active in June 2006. The southern part of this line constitutes the western border of the low basin and has a steep gradient on its western side up to the Uppland mainland. The deep basin is filled with Jotnian metasediments. South of this basin, the Uppland mainland continues under water towards the east. South of Aaland an east-north-easterly ridge separates the low basin to the north from an east-west trending trough which is the eastern continuation of a major onland structure

  14. Building Coastal Resilience to sea-level rise and storm hazards: supporting decisions in the NE USA, Gulf of Mexico, and eastern Caribbean

    Science.gov (United States)

    Shepard, C.; Beck, M. W.; Gilmer, B.; Ferdana, Z.; Raber, G.; Agostini, V.; Whelchel, A.; Stone, J.

    2012-12-01

    Coastal communities are increasingly vulnerable to coastal hazards including storm surge and sea level rise. We describe the use of Coastal Resilience, an approach to help support decisions to reduce socio-economic and ecological vulnerability to coastal hazards. We provide examples of this work from towns and cities around Long Island Sound (NY, CT) and the Gulf of Mexico (FL, AL, MS, LA, TX) in the USA and from the Eastern Caribbean (Grenada, St. Vincent and the Grenadines). All of these shores are densely populated and have significant coastal development only centimetres above the sea. This makes people and property very vulnerable and threatens coastal wetlands (marsh, mangrove) and reefs (oyster, coral) that provide habitat and natural buffers to storms while providing other ecosystem services. We describe this work specifically and then offer broader perspectives and recommendations for using ecological habitats to reduce vulnerability to coastal hazards. The Nature Conservancy's Coastal Resilience approach is driven by extensive community engagement and uses spatial information on storm surge, sea level rise, ecological and socio-economic variables to identify options for reducing the vulnerability of human and natural communities to coastal hazards (http://www.coastalresilience.org). We have worked with local communities to map current and future coastal hazards and to identify the vulnerable natural resources and human communities. Communities are able to visualize potential hazard impacts and identify options to reduce them within their existing planning and regulatory frameworks.

  15. Occurrence and distribution of Vibrio spp., Listonella spp., and Clostridium botulinum in the Seto Inland Sea of Japan.

    OpenAIRE

    Venkateswaran, K; Nakano, H; Okabe, T; Takayama, K; Matsuda, O; Hashimoto, H

    1989-01-01

    The distribution of Vibrio species in samples of surface water, bottom water (water 2 m above the sediment), and sediment from the Seto Inland Sea was studied. A simple technique using a membrane filter and short preenrichment in alkaline peptone water was developed to resuscitate the injured cells, followed by plating them onto TCBS agar. In addition, a survey was conducted to determine the incidence of Clostridium botulinum in sediment samples. Large populations of heterotrophs were found i...

  16. A model study of the seasonality of sea surface temperature and circulation in the Atlantic North-Eastern Tropical Upwelling System.

    Directory of Open Access Journals (Sweden)

    Saliou eFaye

    2015-09-01

    Full Text Available The climatological seasonal cycle of the sea surface temperature (SST in the north-eastern tropical Atlantic (7-25°N, 26-12°W is studied using a mixed layer heat budget in a regional ocean general circulation model. The region, which experiences one of the larger SST cycle in the tropics, forms the main part of the Guinea Gyre. It is characterized by a seasonally varying open ocean and coastal upwelling system, driven by the movements of the intertropical convergence zone (ITCZ. The model annual mean heat budget has two regimes schematically. South of roughly 12°N, advection of equatorial waters, mostly warm, and warming by vertical mixing, is balanced by net air-sea flux. In the rest of the domain, a cooling by vertical mixing, reinforced by advection at the coast, is balanced by the air-sea fluxes. Regarding the seasonal cycle, within a narrow continental band, in zonal mean, the SST early decrease (from September, depending on latitude, until December is driven by upwelling dynamics off Senegal and Mauritania (15°-20°N, and instead by air-sea fluxes north and south of these latitudes. Paradoxically, the later peaks of upwelling intensity (from March to July, with increasing latitude essentially damp the warming phase, driven by air-sea fluxes. The open ocean cycle to the west, is entirely driven by the seasonal net air-sea fluxes. The oceanic processes significantly oppose it, but for winter north of ~18°N. Vertical mixing in summer-autumn tends to cool (warm the surface north (south of the ITCZ, and advective cooling or warming by the geostrophic Guinea Gyre currents and the Ekman drift. This analysis supports previous findings on the importance of air-sea fluxes offshore. It mainly offers quantitative elements on the modulation of the SST seasonal cycle by the ocean circulation, and particularly by the upwelling dynamics.Keywords: SST, upwelling, circulation, heat budget, observations, modeling

  17. Diversity of moderate El Niño events evolution: role of air-sea interactions in the eastern tropical Pacific

    Science.gov (United States)

    Dewitte, Boris; Takahashi, Ken

    2017-12-01

    In this paper we investigate the evolution of moderate El Niño events during their developing phase with the objective to understand why some of them did not evolve as extreme events despite favourable conditions for the non-linear amplification of the Bjerknes feedback (i.e. warm SST in Austral winter in the eastern equatorial Pacific). Among the moderate events, two classes are considered consisting in the Eastern Pacific (EP) El Niño events and Central Pacific (CP) events. We first show that the observed SST variability across moderate El Niño events (i.e. inter-event variability) is largest in the far eastern Pacific (east of 130°W) in the Austral winter prior to their peak, which is associated to either significant warm anomaly (moderate EP El Niño) or an anomaly between weak warm and cold (moderate CP El Niño) as reveals by the EOF analysis of the SST anomaly evolution during the development phase of El Niño across the El Niño years. Singular value decomposition (SVD) analysis of SST and wind stress anomalies across the El Niño years further indicates that the inter-event SST variability is associated with an air-sea mode explaining 31% of the covariance between SST and wind stress. The associated SST pattern consists in SST anomalies developing along the coast of Ecuador in Austral fall and expanding westward as far as 130°W in Austral winter. The associated wind stress pattern features westerlies (easterlies) west of 130°W along the equator peaking around June-August for EP (CP) El Niño events. This air-sea mode is interpreted as resulting from a developing seasonal Bjerknes feedback for EP El Niño events since it is shown to be associated to a Kelvin wave response at its peak phase. However equatorial easterlies east of 130°W emerge in September that counters the growing SST anomalies associated to the air-sea mode. These have been particularly active during both the 1972 and the 2015 El Niño events. It is shown that the easterlies are

  18. Processes regulating pCO2 in the surface waters of the central eastern Gotland Sea: a model study

    Directory of Open Access Journals (Sweden)

    Bernd Schneider

    2011-09-01

    Full Text Available This work presents a one-dimensional simulation of the seasonal changes in CO2 partial pressure (pCO2. The results of the model were constrained using data from observations, which improved the model's ability to estimate nitrogen fixation in the central Baltic Sea and allowed the impact of nitrogen fixation on the ecological state of the Baltic Sea to be studied. The model used here is the public domain water-column model GOTM (General Ocean Turbulence Model, which in this study was coupled with a modifed Baltic Sea ecosystem model, ERGOM (The Baltic Sea Research Institute's ecosystem model. To estimate nitrogen fixation rates in the Gotland Sea, the ERGOM model was modified by including an additional cyanobacteria group able to fix nitrogen from March to June. Furthermore, the model was extended by a simple CO2 cycle. Variable C:P and N:P ratios, controlled by phosphate concentrations in ambient water, were used to represent cyanobacteria, detritus and sediment detritus. This approach improved the model's ability to reproduce sea-surface phosphate and pCO2 dynamics. The resulting nitrogen fixation rates in 2005 for the two simulations, with and without the additional cyanobacteria group, were 259 and 278 mmol N m-2 year-1respectively.

  19. Analysis of gravity anomalies in the Ulleung Basin (East Sea/Sea of Japan) and its implications for the crustal structure of rift-dominated back-arc basin

    Science.gov (United States)

    Kim, Yoon-Mi; Lee, Sang-Mook

    2018-01-01

    The Ulleung Basin (UB), one of three major basins in the East Sea/Sea of Japan, is considered to represent a continental-rifting end-member of back-arc basin system, but is much less understood compared to the nearby Yamato Basin (YB) and Japan Basin (JB). This study examines the gravity anomalies of the UB since the variation in crustal thickness can provide important insights on the mode of extension during basin opening. Our analysis shows that the Moho depth (from the sea surface) varies from 16 km at the basin center to 22 km at the edges. However, within the central part of the basin, the crustal thickness (not including sediment) is more or less the same (10-12 km), by varying only about 10-20% of the total thickness, contrary to the previous suggestions. Our finding of anomalous but uniformly thick crust is consistent with the recent seismic results from the YB (14 km on average). A mantle residual gravity anomaly high (∼20 mGal) exists in the northeastern part of the UB. This feature is interpreted as the location of maximum extension (slightly thinner crust by ∼1 km). Together with another moderate gravity high to the southwest, the two anomalies form a NNE-SSW line, which corresponds to the direction of the major tectonic structures of the Korean Peninsula. We argue that the a massive magmatic emplacement took place extensively in the lower crust of the UB during the opening, significantly increasing its overall thickness to almost twice as that of the JB where a mid-ocean-ridge style seafloor spreading occurred. Two important post-opening processes took place after the formation of uniformly thick crust: post-rift volcanic intrusions in the north, especially in its northeast sections but had little effect on the residual gravity anomaly itself, and the deflection of crust in response to differential sediment loading towards the south, producing the median high in the basement in response to the flexural bending. We also conducted a simple test to

  20. Absorption and fluorescence properties of chromophoric dissolved organic matter of the eastern Bering Sea in the summer with special reference to the influence of a cold pool

    Science.gov (United States)

    D'Sa, E. J.; Goes, J. I.; Gomes, H.; Mouw, C.

    2014-06-01

    The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a cold pool (Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 m-1) and a high S (mean 25.95 ± 1.58 μm-1) suggested substantial photobleaching of the Alaska Coastal Water, but high intensities of humic-like and protein-like fluorescence suggested sources of fluorescent DOM from coastal runoff and glacier meltwaters during the summer. The spectral slope S vs. ag355 relationship revealed terrestrial and oceanic end members along with intermediate water masses that were modeled using nonlinear regression equations that could allow water mass differentiation based on CDOM optical properties. Spectral slope S was negatively correlated (r2 = 0.79) with apparent oxygen utilization (AOU) for waters extending from the middle shelf into the deep Bering Sea indicating increasing microbial alteration of CDOM with depth. Although our data show that the CDOM photochemical environment of the Bering Sea is complex, our current information on its optical properties will aid in better understanding of the biogeochemical role of CDOM in carbon budgets in relation to the annual sea ice and phytoplankton dynamics, and to improved algorithms of ocean color remote sensing for this region.

  1. Change in the intensity of low-salinity water inflow from the Bay of Bengal into the Eastern Arabian Sea from the Last Glacial Maximum to the Holocene: Implications for monsoon variations

    Digital Repository Service at National Institute of Oceanography (India)

    Mahesh, B.S.; Banakar, V.K.

    A 100–400 km wide region of the coastal Eastern Arabian Sea (EAS), off the west-coast of India, is characterized by a low-salinity tongue formed by the inflow of low-salinity surface water from the Bay of Bengal (BoB). This low-salinity tongue...

  2. [The natural resources of the expedition bay as a basis for the creation of the health resort centre at the coast of the Peter the Great Bay, the Sea of Japan].

    Science.gov (United States)

    Vasil'chenko, V F; Badalov, N G; Derkacheva, L N

    2014-01-01

    The present article presents characteristics of the therapeutic and health promoting potential of the Expedition Bay, (part of the Peter the Great Bay, the Sea of Japan), known to be a deposit of therapeutic sea muds. The great variety of local therapeutic natural resources, viz. sea muds, sea weeds, friendly climate, beeches, etc., can be used for the treatment and prevention of various diseases. The Expedition Bay was designated as a local area of recreational and therapeutic value that can be used as a basis for the creation and further development of the multi-field health resort centre (or medical spa) that would attract patients from other regions of Russia and the surrounding countries. The future centre would provide medical services based in the first place on the classical methods of climatic and peloid therapy, thalassotherapy (heliotherapy, aeroionotherapy, bathing, marine algae therapy, etc.) as well as the modern balneotherapeutic and spa technologies, therapeutic tourism for the purpose of rehabilitation and health promotion.

  3. A laboratory and field study of 210Po depuration by edible winkles (Littorina littorea L.) from the Cumbrian coast (north-eastern Irish Sea)

    International Nuclear Information System (INIS)

    Swift, D.J.; Smith, D.L.; Allington, D.J.; Winpenny, K.

    1995-01-01

    Edible winkles from Saltom Bay, Cumbria (north-eastern Irish Sea) had flesh 210 Po concentrations in excess of 200 Bq kg -1 (wet). This came from liquid waste discharged under authorisation from a chemical plant producing phosphoric acid. This labelling of the winkles under natural conditions was exploited to determine the 210 Po depuration rate and biological half-time. Winkles transferred to Lowestoft and depurated in flowing seawater had biological half-times ranging from 82 to 119 days depending on temperature. After the chemical plant was shut, changes in Saltom Bay winkle flesh contents of 210 Po, 210 Pb and cadmium were followed by monthly samples. The biological half-time in the environment for the decrease in 210 Po after the plant closed was estimated at about 92 days. (author)

  4. Comparative Reproduction Aspects of the Deep-water Shrimps Aristaeomorpha foliacea and Aristeus antennatus (Decapoda, Aristeidae in the Greek Ionian Sea (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    K. Kapiris

    2009-01-01

    Full Text Available In the eastern Ionian Sea, the deep-water shrimps Aristaeomorpha foliacea and Aristeus antennatus constitute a virgin fishing resource, since their maximum abundance depth exceeds commercial exploitation depths. The two sympatric species share a number of common reproductive features, such as summer reproduction. A slight temporal shift in mating activity, ovarian maturation, and spawning period was observed between species. The most notable difference was the more pronounced seasonality in reproductive activity of Aristeus antennatus compared to that of A. foliacea as evidenced by the frequency of inseminated females and functionally mature males, as well as by the shorter ovarian maturation period. Nevertheless, regarding the whole life span, both sexes of Aristeus antennatus exhibit a more extended reproductive activity in comparison to A. foliacea. No notable differentiation of both species existed in comparison to other Mediterranean regions.

  5. Relationships between lake-level changes and water and salt budgets in the Dead Sea during extreme aridities in the Eastern Mediterranean

    Science.gov (United States)

    Kiro, Yael; Goldstein, Steven L.; Garcia-Veigas, Javier; Levy, Elan; Kushnir, Yochanan; Stein, Mordechai; Lazar, Boaz

    2017-04-01

    Thick halite intervals recovered by the Dead Sea Deep Drilling Project cores show evidence for severely arid climatic conditions in the eastern Mediterranean during the last three interglacials. In particular, the core interval corresponding to the peak of the last interglacial (Marine Isotope Stage 5e or MIS 5e) contains ∼30 m of salt over 85 m of core length, making this the driest known period in that region during the late Quaternary. This study reconstructs Dead Sea lake levels during the salt deposition intervals, based on water and salt budgets derived from the Dead Sea brine composition and the amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of dissolved Na+ and Cl- accumulates during wetter intervals. Based on the compositions of Dead Sea brines from pore waters and halite fluid inclusions, we estimate that ∼12-16 cm of halite precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg2+ concentration increases and the Na+/Cl- ratio decreases in the lake. Our calculations indicate major lake-level drops of ∼170 m from lake levels of 320 and 310 m below sea level (mbsl) down to lake levels of ∼490 and ∼480 mbsl, during MIS 5e and the Holocene, respectively. These lake levels are much lower than typical interglacial lake levels of around 400 mbsl. These lake-level drops occurred as a result of major decreases in average fresh water runoff, to ∼40% of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ∼600 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average. The halite intervals include

  6. Flux and stable C and N isotope composition of sinking particles in the Ulleung Basin of the East/Japan Sea

    Science.gov (United States)

    Hyun Kwak, Jung; Han, Eunah; Hwang, Jeomshik; Kim, Young, II; Lee, Chung Il; Kang, Chang-Keun

    2017-09-01

    Seasonal variability of sinking fluxes of total mass (TMF), particulate organic carbon and nitrogen (POC and PON) was examined using sinking particles collected from sediment traps during July 2011 to December 2011, and December 2012 to June 2013 at an offshore channel site; and from November 2013 to August 2014 at a nearshore slope site of the Ulleung Basin in the East/Japan Sea. δ13C and δ15N values of sinking particles were measured to elucidate the major export processes of POC and PON. Annual TMF (112-638 g m-2 yr-1) and fluxes of POC and PON (9.6-32.1 g C m-2 yr-1 and 1.2-4.5 g N m-2 yr-1, respectively) in the Ulleung Basin corresponded to the upper limit of values reported for other open seas and oceans in the world. No great seasonal variability in both quantitative (TMF, and fluxes and contents of POC and PON) and qualitative (C/N ratios, and δ13C and δ15N values) estimates of vertical fluxes was observed, reflecting a steady standing stock of chlorophyll a in the upper part of water column. Furthermore, high contents of POC and PON and nearly constant δ13C and δ15N values in sinking particles collected in the sediment traps, indicate that primary production in the euphotic zone may be a good predictor of TMF and export flux of organic matter. In this regard, our pilot study points out the importance of high annual primary production and low water temperature (sources such as lateral advection through resuspended clay mineral, and aeolian and terrestrial inputs to the sedimentary flux.

  7. European Integration and the Transition of Eastern European States. The New Central Europe and Romania's Interest in Regional Cooperation in the Black Sea - Danube Region

    Directory of Open Access Journals (Sweden)

    Flore POP

    2003-01-01

    Full Text Available This short article presents the most important directions of the evolution of Central and Eastern Europe during the second half of the 20th century during the period marked by the coming into power and then the downfall of the communism. One could also note that the Central and Eastern European countries have undergone several political and economic transitions- and for Romania’s case- the burdening heritage of the austerity economic policy that has been implemented during the years will affect the economic development of the countries on the long term. The transition towards market economy was realized upon the political decision of political accession to the free market principle. The new beginning of the regional integration process made the countries in the Danube-Black Sea region, sign new agreements for political and economic cooperation. The emergence of new countries on European and Asian maps opens new opportunities for regional cooperation, especially for environmental issues, which brings new dimensions for the global process of European integration and of the integration of the regional economies into the global economies.

  8. Discovering where bluefin tuna, Thunnus thynnus, might go: using environmental and fishery data to map potential tuna habitat in the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Dimitrios Damalas

    2012-11-01

    Full Text Available Based on a dataset derived from commercial fisheries in the eastern Mediterranean Sea in 1998-2005, we applied generalized additive models (GAMs to investigate the relative influence of a range of environmental factors on catch rates of Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1785. GAM analyses were conducted by separately modelling (1 the probability of making a catch (encountering a school, and (2 the positive catch rates (school size. Results suggested intra-annual variations in tuna distribution and revealed interesting associations with some environmental features, lunar periodicity being the most distinctive one. Probability of encountering a school peaked in late spring months, eastwards, at water temperatures above 22°C and around the full moon. Size of school was more likely to be larger in northeasternmost regions and in the vicinity of land in late spring, when the percentage of lunar disc illumination was higher. A moderate but continuous annual decline in the probability of encountering a bluefin tuna school was detected from the models’ outputs. The models were used as an indication of preference or association for the selected environmental variables. Based on these associations, an indirect identification of the bluefin tuna potential habitat was obtained and used to map distributions in the eastern Mediterranean region.

  9. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Directory of Open Access Journals (Sweden)

    John M Maniscalco

    Full Text Available Steller sea lion (Eumetopias jubatus numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  10. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus) in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Science.gov (United States)

    Maniscalco, John M; Springer, Alan M; Adkison, Milo D; Parker, Pamela

    2015-01-01

    Steller sea lion (Eumetopias jubatus) numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population) in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ) was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  11. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the SEIFU MARU in the Sea of Japan from 2008-10-21 to 2008-11-25 (NODC Accession 0112358)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112358 includes biological, chemical, discrete sample, physical and profile data collected from SEIFU MARU in the Sea of Japan from 2008-10-21 to...

  12. Testing sea-level markers observed in ground-penetrating radar data from Feddet, south-eastern Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Nielsen, Lars; Clemmensen, Lars B

    2012-01-01

    a number of profile lines across less than c. 60 years old berm, beach ridge and swale structures at the Feddet peninsula. The GPR images allow us to interpret internal sedimentary architecture, and here we focus especially on the identification of downlapping reflections, which are interpreted to mark...... fluctuations in past sea level due to variations in tidal effects and meteorological conditions (isostatic rebound is expected to have a minimal effect on Feddet (Hansen et al., 2011)). Comparison with existing time series of measurements of actual sea level from the Danish Maritime Safety Administration (from...

  13. Geological and Structural evolution of the Eurasia Africa plate boundary in the Gulf of Cadiz Central Eastern Atlantic Sea.

    OpenAIRE

    D’Oriano, Filippo

    2010-01-01

    Iberia Africa plate boundary, cross, roughly W-E, connecting the eastern Atlantic Ocean from Azores triple junction to the Continental margin of Morocco. Relative movement between the two plate change along the boundary, from transtensive near the Azores archipelago, through trascurrent movement in the middle at the Gloria Fracture Zone, to transpressive in the Gulf of Cadiz area. This study presents the results of geophysical and geological analysis on the plate boundary area offshore Gibral...

  14. Discharge of perfluorinated compounds from rivers and their influence on the coastal seas of Hyogo prefecture, Japan.

    Science.gov (United States)

    Takemine, Shusuke; Matsumura, Chisato; Yamamoto, Katsuya; Suzuki, Motoharu; Tsurukawa, Masahiro; Imaishi, Hiromasa; Nakano, Takeshi; Kondo, Akira

    2014-01-01

    The aim of this study was to investigate 12 perfluorinated compounds (PFCs) including perfluorinated carboxylates (C4-C12) and perfluorinated alkyl sulfonates (C4, C6, and C8) in river and seawater samples to determine contamination levels in the aquatic environment of Hyogo prefecture, Japan. High levels of perfluorohexanoic acid (PFHxA; 2300-16,000 ng/L) were detected in the Samondogawa River at Tatsumi Bridge downstream of a PFC production facility; this location also had the highest mass flow rate of PFCs (3900-29,000 kg/y). Widespread contamination of coastal waters was confirmed with PFHxA as the dominant compound. Perfluorooctanoic acid was also prevalent in coastal waters. The concentration of PFHxA in coastal seawater and the distance from the mouth of the Samondogawa River were inversely related. This discharge of high concentrations of PFHxA from the Samondogawa River may have affected concentrations of PFCs in Osaka Bay. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Detection of a High-Density Brachiolaria-Stage Larval Population of Crown-of-Thorns Sea Star (Acanthaster planci in Sekisei Lagoon (Okinawa, Japan

    Directory of Open Access Journals (Sweden)

    Go Suzuki

    2016-03-01

    Full Text Available Outbreaks of the crown-of-thorns sea star (Acanthaster planci are likely to be strongly associated with drastic changes in larval survival influenced by food availability. However, no quantitative or qualitative data are available on the distribution of A. planci larvae in the field nor on the environmental factors that influence their survivorship. Here we use a DNA barcoding approach to describe the distribution of A. planci larvae in Sekisei Lagoon, Ryukyu Archipelago, Japan after conducting three days of high-intensity sampling. High densities (53.3 individuals/m3 of A. planci larvae were found outside of Yonara Channel, which is the largest reef channel in this lagoon. Surprisingly, most (94% of the aggregated larvae were advanced-stage brachiolaria. Considering that it takes several days to develop to this stage, this result demonstrates that A. planci larvae were floating for some time and maintaining a high-density population. However, this dense larval cloud disappeared immediately after a typhoon. No spatial correlation was found between larval density and either nutrient or chlorophyll a concentrations, suggesting that A. planci larvae do not necessarily aggregate in nutrient-rich water. These data suggest that some high-density populations of late developmental stage A. planci larvae were produced under a low phytoplankton concentration and could potentially trigger an adult outbreak. Consequently, our data suggest that adult outbreaks may not necessarily be triggered by food availability alone.

  16. Coexistence of microalgal sedimentation and water column recycling in a seasonally ice-covered ecosystem (Saroma-ko Lagoon, Sea of Okhotsk, Japan)

    Science.gov (United States)

    Michel, C.; Legendre, L.; Taguchi, S.

    1997-02-01

    Seasonal variations in under-ice microalgal sedimentation and plankton dynamics in Saroma-ko, a shallow seasonally ice-covered lagoon (Sea of Okhotsk, Hokkaido, Japan), were followed during a 4-week period at the end of winter. At 3-4 day intervals, sediment traps were deployed at three depths from the undersurface of the ice and water column samples were collected. Sampled variables included chlorophyll a (chl a) and pheopigments, particulate organic carbon and nitrogen (POC, PON), cell identification and enumeration, biogenic silica and dissolved inorganic nutrients. POC/PON, POC/chl a and Si/chl a ratios for suspended biomass as well as cell counts showed the presence of a diversified phytoplankton assemblage with a high microheterotrophic biomass. A major peak in algal sedimentation occurred at the end of the sampling season (chl a flux ca. 5 mg m -2 d -1); the sedimented algae included both ice algae and phytoplankton species. Ice algae did not remain suspended in the plankton biomass, but sedimented rapidly upon release from the ice matrix. Results show that Saroma-ko had a rather special food web structure at the end of winter, when both high microalgal export and water column recycling simultaneously occurred under the ice cover.

  17. Spatial distribution of the crab larvae (Decapoda: Anomura et Brachyura) in Possyet Bay (Peter the Great Bay of the Sea of Japan) in 2000-2001

    Science.gov (United States)

    Grigoryeva, N. I.

    2009-10-01

    The analysis of the data obtained during the plankton surveys in Possyet Bay (Peter the Great Bay of the Sea of Japan) in 2000-2001 is presented. The larvae of eight crab species were registered in the plankton: the red king crab Paralithodes camtschaticus (Tilesius, 1815), the snow (opilio) crab Chionoecetes opilio (Fabricius, 1780), the Arctic lyre crab Hyas coarctatus ursinus (Leach, 1815), the kelp crab Pugettia quadridens (de Haan, 1839), the helmet crab Telmessus cheiragonus (Tilesius, 1815), the Japanese swimming crab Charybdis japonica (A. Milne-Edwards, 1861), the pea crab Pinnixa rathbuni (Sakai, 1934), and the porcelain crab Pachycheles stevensii (Stimpson, 1858). These species belonged to six families: Lithodidae, Atelecyclidae, Majidae, Portunidae, Porcellanidae, and Pinnotheridae. The role of the variability of some of the hydrological factors in the meroplankton larvae development was studied. In May, the crab larvae were found mostly in the open part of the bay. In June, they were transported by the current to the northern part of the bay. In July, they spread uniformly in all the bay areas; however, patchiness was observed. The maximal population density of the crab larvae was registered for July and varied from 6.8 to 23.3 ind. m-3. The crab larvae appeared in the plankton in 2000 and 2001 earlier than for the average season.

  18. Relationships between fish, sea urchins and macroalgae: The structure of shallow rocky sublittoral communities in the Cyclades, Eastern Mediterranean

    Science.gov (United States)

    Giakoumi, Sylvaine; Cebrian, Emma; Kokkoris, Giorgos D.; Ballesteros, Enric; Sala, Enric

    2012-08-01

    Historical overfishing is the most likely explanation for the depletion of the shallow sublittoral communities in many areas not least in the Cyclades Archipelago, Greece. The present study is the first quantitative study of the shallow rocky sublittoral of the Cyclades based on in situ underwater surveys of algal cover, and fish and sea urchin abundance at 181 sampling sites in 25 islands to provide a baseline and investigate the relationship between these communities. Algal turf was the most abundant algal functional group, and canopy algae of the genus Cystoseira were more abundant at the northern islands. A range in fish biomass of almost two orders of magnitude was found across islands, but overall the Cyclades displayed much lower values than fished areas of the Western Mediterranean. We observed apex predators only in 25% of our sampling sites, and their biomass was uncorrelated to total fish biomass, indicating a depleted ecosystem. Sea urchin biomass was also low but similar to values found in other Mediterranean islands and was positively correlated with barrens. We observed a gradient of benthic community complexity from sea urchin barrens to communities dominated by Cystoseira spp. There was no correlation between sea urchins and their predators Diplodus spp., which presented extremely low densities.

  19. Neoascarophis macrouri n. sp. (Nematoda: Cystidicolidae) from the stomach of Macrourus berglax (Macrouridae) in the eastern Greenland Sea

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Klimpel, S.; Kara, E.

    2006-01-01

    Roč. 63, č. 3 (2006), s. 231-237 ISSN 0165-5752 R&D Projects: GA ČR(CZ) GA524/06/0170 Institutional research plan: CEZ:AV0Z60220518 Keywords : Neoascarophis * Macrourus * Greenland Sea Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.856, year: 2006

  20. November 2009 tropical cyclone Phyan in the eastern Arabian Sea: Oceanic response along west India coast and Kavaratti lagoon

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desai, R.G.P.; Mehra, P.; VijayKumar, K.; Agarvadekar, Y.; Ryan, L.; Rivankar, P.; Viegas, B.

    ), sea surface cooling (approx. 5 degrees C at Calicut), and surge flooding (approx. 80 cm at Verem). Several factors such as (1) water piling up at the coast supported by seaward flow of the excess water in the rivers due to heavy rains and westerly...

  1. Monsoon driven changes in phytoplankton populations in the eastern Arabian Sea as revealed by microscopy and HPLC pigment analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Parab, S.G.; Matondkar, S.G.P.; Gomes, H.; Goes, J.I.

    Like the rest of the Arabian Sea, the west coast of India is subject to semi-annual wind reversals associated with the monsoon cycle that result in two periods of elevated phytoplankton productivity, one during the northeast (NE) monsoon (November...

  2. Altimeter-derived flow field over a newly identified coastal ocean boundary in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Somayajulu, Y.K.; Swamy, G.N.

    part, tapers off towards north and bulges towards south. In the present communication, the T/P-derived flow pattern over this new boundary is presented. The derived flow pattern shows the general dominance of meso-scale eddies in the Arabian Sea...