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Sample records for northern philippine sea

  1. The Northern Philippine Sea: A Bioregional Development Communication Strategy

    Directory of Open Access Journals (Sweden)

    Marivic G. Pajaro

    2013-12-01

    Full Text Available The Philippine marine management challenge requires a scaled up ecosystem approach to the biodiversity-based bioregional level used in marine spatial planning. The related communication challenge is being addressed by a currently informal consortium that includes non-government organizations, local government units, as well as state colleges and universities. The evolving communication strategy described here is focused upon considerations that include local government mandates, status of marine development, provinceby- province assessment of coastal economies, cultural relevance, academic programming, and the need for national inputs on counterpart funding. The current work provides a possible model for Philippine application in all marine bioregions. The concept of the bioregional approach was systematically advocated across one bioregion, the Northern Philippine Sea. The Philippine strategy of development communication was used as a template to promote the development of a bioregional approach by establishing an initial level of participation involving the provincial governments as well as the state universities and colleges.

  2. Nitrate dual isotopic composition in the northern South China Sea and neighboring West Philippine Sea

    Science.gov (United States)

    Yang, J.; Xu, M.; Wu, Y.; Dai, M.; Kao, S.

    2013-12-01

    Nitrate nitrogen and oxygen isotopic compositions (δ15NNO3 and δ18ONO3) were used to diagnose nitrate dynamics and the origins of water masses in the northern South China Sea (SCS) and West Philippine Sea (WPS) where water exchanges via the Luzon Strait at different depths. In the SCS, 1-3‰ greater upward increase in δ18ONO3 relative to corresponding δ15NNO3 was just observed in the lower euphotic zone (EZ), indicating a rapid internal cycle of nitrate assimilation and remineralization. Much lower nitrate concentration in the EZ of WPS does not allow us to measure its dual isotopes. From 500 m deep to the base of EZ in the WPS, non-proportional decreases in δ15NNO3 (from 6.4‰ to 2.1-2.6‰) and δ18ONO3 (from 3.0‰ to 1.1‰) accompanying with elevated N:P ratio anomalies (N* from -1.2 μM up to 2 μM), suggest the accumulation of atmospheric-derived N (e.g. N2 fixation and/or N deposition). This allochthonous N signal cumulated in the subsurface of WPS may regulate the δ15NNO3 in the SCS subsurface due to seasonal Kuroshio intrusion, which could supply isotopically light nitrate as newly fixed N source to the SCS. The higher (~0.5‰) δ15NNO3 and δ18ONO3 values, associated with lower N* were detected in the WPS intermediate water (WPS-IW, σθ = 26.5~27.1 kg m-3) around depth of 600-800 m (especially at a southern site) when compared to those of the conventional water source coming from North Pacific Intermediate Water (NPIW). By combining nitrate concentration, N* and δ15NNO3 as constraints, we propose that an additional southerly source other than NPIW may feed into the WPS-IW. On the other hand, the SCS intermediate water (SCS-IW, ~400-700 m), which supposedly sourced from WPS-IW along similar isopycnal levels, showed ~1‰ lower δ15NNO3 and δ18ONO3 values. This reduction in nitrate duel isotopes indicates intense diapycnal mixing primarily due to basin-wide upwelling in the SCS interior. This is the first hand data in the SCS for deep profiles

  3. Global sea-level rise is recognised, but flooding from anthropogenic land subsidence is ignored around northern Manila Bay, Philippines.

    Science.gov (United States)

    Rodolfo, Kelvin S; Siringan, Fernando P

    2006-03-01

    Land subsidence resulting from excessive extraction of groundwater is particularly acute in East Asian countries. Some Philippine government sectors have begun to recognise that the sea-level rise of one to three millimetres per year due to global warming is a cause of worsening floods around Manila Bay, but are oblivious to, or ignore, the principal reason: excessive groundwater extraction is lowering the land surface by several centimetres to more than a decimetre per year. Such ignorance allows the government to treat flooding as a lesser problem that can be mitigated through large infrastructural projects that are both ineffective and vulnerable to corruption. Money would be better spent on preventing the subsidence by reducing groundwater pumping and moderating population growth and land use, but these approaches are politically and psychologically unacceptable. Even if groundwater use is greatly reduced and enlightened land-use practices are initiated, natural deltaic subsidence and global sea-level rise will continue to aggravate flooding, although at substantially lower rates.

  4. Estimating the horizontal and vertical direction-of-arrival of water-borne seismic signals in the northern Philippine Sea.

    Science.gov (United States)

    Freeman, Simon E; D'Spain, Gerald L; Lynch, Stephen D; Stephen, Ralph A; Heaney, Kevin D; Murray, James J; Baggeroer, Arthur B; Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A

    2013-10-01

    Conventional and adaptive plane-wave beamforming with simultaneous recordings by large-aperture horizontal and vertical line arrays during the 2009 Philippine Sea Engineering Test (PhilSea09) reveal the rate of occurrence and the two-dimensional arrival structure of seismic phases that couple into the deep ocean. A ship-deployed, controlled acoustic source was used to evaluate performance of the horizontal array for a range of beamformer adaptiveness levels. Ninety T-phases from unique azimuths were recorded between Yeardays 107 to 119. T-phase azimuth and S-minus-P-phase time-of-arrival range estimates were validated using United States Geological Survey seismic monitoring network data. Analysis of phases from a seismic event that occurred on Yearday 112 near the east coast of Taiwan approximately 450 km from the arrays revealed a 22° clockwise evolution of T-phase azimuth over 90 s. Two hypotheses to explain such evolution-body wave excitation of multiple sources or in-water scattering-are presented based on T-phase origin sites at the intersection of azimuthal great circle paths and ridge/coastal bathymetry. Propagation timing between the source, scattering region, and array position suggests the mechanism behind the evolution involved scattering of the T-phase from the Ryukyu Ridge and a T-phase formation/scattering location estimation error of approximately 3.2 km.

  5. The Role of Philippine Sea Plate to the Genesis of Quaternary Magmas of Northern Kyushu Island, Japan, Inferred from Along-Arc Geochemical Variations

    Science.gov (United States)

    Shibata, T.; Yoshikawa, M.; Itoh, J.; Ujike, O.; Miyoshi, M.; Takemura, K.

    2013-12-01

    Quaternary volcanoes on Kyushu Island comprise volcanoes Himeshima, Futagoyama, Yufu-Tsurumi, Kuju, Aso, Kirishima and Sakurajima from north to south alongstrike the volcanic front. Adakitic lavas are observed from Yufu-Tsurumi and Kuju volcanoes in northern Kyushu (Kita et al., 2001; Sugimoto et al., 2007), whereas no Quaternary adakites were observed at Aso (e.g., Hunter, 1998) and the volcanoes south of Aso along the entire Ryukyu arc. Sugimoto et al. (2007) suggested that the trace element and Sr, Nd, and Pb isotopic compositions of adakitic magmas from Yufu-Tsurumi volcano indicate derivation of the magmas by partial melting of the subducting PSP. In contrast, Zellmer et al. (2012) suggested that these adakites may have formed by fractional crystallization of mantle-derived mafic magmas within the garnet stability field in the crust. The Honshu-Kyushu arc transition is a particular favorable setting to address these controversial models for the origin of the adakitic lavas, because of the potential relationship between the PSP materials and the alongstrike variation of the lava chemistry. The Palau-Kyushu ridge divides the oceanic crust of the PSP into northeastern and southwestern segments with ages of 26-15 (Shikoku Basin) and 60-40 Ma (West Philippine Basin), respectively (Mahony et al., 2011). Although there are no clear plate images beneath northern Kyushu, the northern extension of the Palau-Kyushu ridge potentially corresponds to the boundary between the SW Japan and Ryukyu arcs. If adakite genesis was related to the subducted slab rather than the overlying crust, then the spatial distribution of Quaternary adakites should correlate with the age of the subducted PSP. In order to test such correlation and elucidate the petrogenesis of the northern Kyushu adakites, we compiled major and trace elements and Sr-Nd-Pb isotope ratios from volcanoes along the arc front that includes the transition from adakitic to non-adakitic arc volcanism. Comprehensive

  6. Philippine Sea and East Asian plate tectonics since 52 Ma constrained by new subducted slab reconstruction methods

    Science.gov (United States)

    Wu, Jonny; Suppe, John; Lu, Renqi; Kanda, Ravi

    2016-06-01

    We reconstructed Philippine Sea and East Asian plate tectonics since 52 Ma from 28 slabs mapped in 3-D from global tomography, with a subducted area of ~25% of present-day global oceanic lithosphere. Slab constraints include subducted parts of existing Pacific, Indian, and Philippine Sea oceans, plus wholly subducted proto-South China Sea and newly discovered "East Asian Sea." Mapped slabs were unfolded and restored to the Earth surface using three methodologies and input to globally consistent plate reconstructions. Important constraints include the following: (1) the Ryukyu slab is ~1000 km N-S, too short to account for ~20° Philippine Sea northward motion from paleolatitudes; (2) the Marianas-Pacific subduction zone was at its present location (±200 km) since 48 ± 10 Ma based on a >1000 km deep slab wall; (3) the 8000 × 2500 km East Asian Sea existed between the Pacific and Indian Oceans at 52 Ma based on lower mantle flat slabs; (4) the Caroline back-arc basin moved with the Pacific, based on the overlapping, coeval Caroline hot spot track. These new constraints allow two classes of Philippine Sea plate models, which we compared to paleomagnetic and geologic data. Our preferred model involves Philippine Sea nucleation above the Manus plume (0°/150°E) near the Pacific-East Asian Sea plate boundary. Large Philippine Sea westward motion and post-40 Ma maximum 80° clockwise rotation accompanied late Eocene-Oligocene collision with the Caroline/Pacific plate. The Philippine Sea moved northward post-25 Ma over the northern East Asian Sea, forming a northern Philippine Sea arc that collided with the SW Japan-Ryukyu margin in the Miocene (~20-14 Ma).

  7. Thermohaline finestructure observed near the northern Philippine coast

    Institute of Scientific and Technical Information of China (English)

    WANG Fan; LI Yuanlong

    2012-01-01

    Using hydrographic measurements from three recent surveys in the western tropical Pacific,this study revealed the existence and general features of thermohaline finestructure near the northem Philippine coast.Pronounced finestructures were detected in the layers of the North Pacific Tropical Water (NPTW) and the North Pacific Intermediate Water (NPIW) during all three cruises and shown to be mainly thermohaline intrusions.Characteristics of the intrusions were further investigated with spiciness curvature and salinity anomaly methods.The vertical scale of the intrusions was 20-50 m and 50-100 m in the NPTW and NPIW layers,respectively.Within the NPTW layer,the Turner angle distribution and correlation between salinity and density anomalies suggested that diffusive convection between surface fresh water and subsurface saline water played an important role in the development and maintenance of the intrusions.In addition,connection between thermohaline finestructure and larger-scale oceanic processes was explored using historical hydrographic data.The results reveal that the salinity field and the distribution of the intrusions in this region were largely determined by mesoscale eddies.As a result of eddy stirring,both isopycnal and diapycnal temperature/salinity gradients were strengthened,which gave rise to the development of thermohaline intrusions.The intrusions acted to enhance heat and salt fluxes and resulted inthe mixing of water masses being more efficient.By linking mesoscale eddy stirring to micro-scale diffusion,thermohaline finestructure plays a vital role in the ocean energy cascade and water mass conversion in the northern Philippine Sea.

  8. 33 CFR 165.1405 - Regulated Navigation Areas and Security Zones; Designated Escorted Vessels-Philippine Sea and...

    Science.gov (United States)

    2010-07-01

    ... Security Zones; Designated Escorted Vessels-Philippine Sea and Apra Harbor, Guam (including Cabras Island... Cabras Island Channel), and Tanapag Harbor, Saipan, Commonwealth of the Northern Mariana Islands (CNMI...″ E. (4) Cabras Island Channel, Guam—All waters from surface to bottom of Cabras Island Channel,...

  9. Seismicity of the Earth 1900-2012 Philippine Sea plate and vicinity

    Science.gov (United States)

    Smoczyk, Gregory M.; Hayes, Gavin P.; Hamburger, Michael W.; Benz, Harley M.; Villaseñor, Antonio; Furlong, Kevin P.

    2013-01-01

    The complex tectonics surrounding the Philippine Islands are dominated by the interactions of the Pacific, Sunda, and Eurasia plates with the Philippine Sea plate (PSP). The latter is unique because it is almost exclusively surrounded by zones of plate convergence. At its eastern and southeastern edges, the Pacific plate is subducted beneath the PSP at the Izu-Bonin, Mariana, and Yap trenches. Here, the subduction zone exhibits high rates of seismic activity to depths of over 600 km, though no great earthquakes (M>8.0) have been observed, likely because of weak coupling along the plate interface. In the northeast, the PSP subducts beneath Japan and the eastern margin of the Eurasia plate at the Nankai and Ryukyu trenches, extending westward to Taiwan. The Nankai portion of this subduction zone has hosted some of the largest earthquakes along the margins of the PSP, including a pair of Mw8.1 megathrust events in 1944 and 1946. Along its western margin, the convergence of the PSP and the Sunda plate is responsible for a broad and active plate boundary system extending along both sides of the Philippine Islands chain. The region is characterized by opposite-facing subduction systems on the east and west sides of the islands, and the archipelago is cut by a major transform structure: the Philippine Fault. Subduction of the Philippine Sea plate occurs at the eastern margin of the islands along the Philippine Trench and its northern extension, the East Luzon Trough. On the west side of Luzon, the Sunda Plate subducts eastward along a series of trenches, including the Manila Trench in the north, the smaller Negros Trench in the central Philippines, and the Sulu and Cotabato trenches in the south. Twentieth and early twentyfirst century seismic activity along the boundaries of the Philippine Sea plate has produced seven great (M>8.0) earthquakes and 250 large (M>7) events. Among the most destructive events were the 1923 Kanto, the 1948 Fukui, and the 1995 Kobe, Japan

  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. Determination of Euler parameters of Philippine Sea plate and the inferences

    Institute of Scientific and Technical Information of China (English)

    臧绍先; 陈起永; 宁杰远; 沈正康; 刘永刚

    2002-01-01

    Euler vectors of 12 plates, including Philippine Sea plate (PH), relative to a randomly fixed Pacific plate(PA) were determined by inverting the 1122 data from NUVEL-1 global plate motion model, earthquake slip vectors along Philippine Sea plate boundary, and GPS observed velocities. Euler vectors of Philippine Sea plate relative to adjacent plates are also gained. Our results are well consistent with observed data and can satisfy the geological and geophysical constraints along the Caroline(CR)-PH and PA-CR boundaries. Deformation of Philippine Sea plate is also discussed by using the plate motion Euler parameters.

  12. Motion of the Philippine Sea plate consistent with the NUVEL-1A model

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    Zang, Shao Xian; Chen, Qi Yong; Ning, Jie Yuan; Shen, Zheng Kang; Liu, Yong Gang

    2002-09-01

    We determine Euler vectors for 12 plates, including the Philippine Sea plate (PH), relative to the fixed Pacific plate (PA) by inverting the earthquake slip vectors along the boundaries of the Philippine Sea plate, GPS observed velocities, and 1122 data from the NUVEL-1 and the NUVEL-1A global plate motion model, respectively. This analysis thus also yields Euler vectors for the Philippine Sea plate relative to adjacent plates. Our results are consistent with observed data and can satisfy the geological and geophysical constraints along the Caroline (CR)-PH and PA-CR boundaries. The results also give insight into internal deformation of the Philippine Sea plate. The area enclosed by the Ryukyu Trench-Nankai Trough, Izu-Bonin Trench and GPS stations S102, S063 and Okino Torishima moves uniformly as a rigid plate, but the areas near the Philippine Trench, Mariana Trough and Yap-Palau Trench have obvious deformation.

  13. Historical record of nuclear activities from (129)I in corals from the northern hemisphere (Philippines).

    Science.gov (United States)

    Bautista, Angel T; Matsuzaki, Hiroyuki; Siringan, Fernando P

    2016-11-01

    Iodine-129 is a long-lived fission product that is majorly released in human nuclear activities (HNA) such as nuclear bomb testing, nuclear fuel reprocessing, and nuclear accidents. It is a good environmental tracer and former measurements of (129)I in corals from the southern hemisphere show the increasing trend of (129)I concentrations in the marine environment caused by HNA. Here we show time series of (129)I/(127(stable))I isotopic ratios in two coral cores from the northern hemisphere (Philippines) and how these record (129)I released from HNA in even greater, unprecedented detail. Corals were taken from the Pacific Ocean (Baler) and South China Sea (Parola) sides of the Philippines. We observed nearly identical peaks ((129)I/(127)I ∼ 31.5 × 10(-12)) in both the Baler and Parola records, each attributed to the year 1962 - the year with the highest recorded amount of (129)I release from nuclear bomb testing. This 1962 (129)I bomb signal offers a new time marker that can be used to establish or confirm age models of corals, comparable to or possibly better than the well-known coral (14)C bomb peak. We also observed nuclear fuel reprocessing and Chernobyl accident (129)I signals in years 1977, 1980, and 1986, concurrently in Parola and with 9 to 11-year lags in Baler. This discrepancy in timing suggests that (129)I was transported to the South China Sea and Pacific Ocean sides of the Philippines directly from the atmosphere and through prevailing ocean currents, respectively. Lastly, we observed surprisingly high (129)I/(127)I isotopic ratios (i.e., 22.8 to 38.9 × 10(-12)) in the Parola record after the year 1996, which is in contrast to the decreasing trend observed in the Baler record and in published (129)I releases of different HNA. These results possibly indicate the presence of unknown sources of (129)I in the South China Sea region.

  14. South China Sea Territorial Disputes and Sino-Philippine Trade

    Institute of Scientific and Technical Information of China (English)

    FANG; WANG

    2015-01-01

    As political factors affect trade activities greatly, this paper considers whether a series of political events have had a negative impact on Sino-Philippine trade relations. Of particular concern is the influence on bilateral relations and the Philippines’ domestic economy from political and diplomatic tensions between China and the Philippines caused by territorial disputes in the South China Sea. Political events are divided into two levels, general conflicts and serious conflicts, which are analyzed from the perspectives of both overall level and product level to present their final impact on trade. This research finds that territorial disputes between the two countries deteriorated trade, as the volume of trade usually decreased distinctly after conflicts. The negative impact on trade generated by serious conflicts usually occurred more rapidly and on a larger scale. The effect of trade deterioration caused by political events weakened over time. Furthermore, after serious conflicts, although the volume of trade of certain products decreased temporarily, it rebounded quickly or even increased soon. However, industrial equipment or industrial raw materials trade activities between the two countries were basically independent of the conflicts’ impact.

  15. Pacific Proving Grounds radioisotope imprint in the Philippine Sea sediments.

    Science.gov (United States)

    Pittauer, Daniela; Roos, Per; Qiao, Jixin; Geibert, Walter; Elvert, Marcus; Fischer, Helmut W

    2017-08-23

    Radionuclide concentrations were studied in sediment cores taken at the continental slope of the Philippine Sea off Mindanao Island in the equatorial Western Pacific. High resolution deposition records of anthropogenic radionuclides were collected at this site. Excess (210)Pb together with excess (228)Th and anthropogenic radionuclides provided information about accumulation rates. Concentrations of Am and Pu isotopes were detected by gamma spectrometry, alpha spectrometry and ICP-MS. The Pu ratios indicate a high portion (minimum of 60%) of Pu from the Pacific Proving Grounds (PPG). This implies that the transport of PPG derived plutonium with the Mindanao Current southward is similarly effective as the previously known transport towards the north with the Kuroshio Current. The record is compared to other studies from northwest Pacific marginal seas and Lombok basin in the Indonesian Archipelago. The sediment core top was found to contain a 6 cm thick layer dominated by terrestrial organic matter, which was interpreted as a result of the 2012 Typhoon Pablo-related fast deposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Vegetation types on Mount Akiki, Northern Luzon, Philippines

    NARCIS (Netherlands)

    Bout, I.E.

    2002-01-01

    Mount Akiki (16° 37’ N, 120° 53’ E, c. 2760 m alt.) is one of the highest mountain peaks in the Cordillera mountain range, Luzon Island, Philippines. It is situated in the municipality of Benguet, north-east of Baguio City (a world famous tourist city in the region) and is north-west of Mt Pulog, Lu

  17. Philippines.

    Science.gov (United States)

    1986-08-01

    The Philippines is an archipelago of 7100 islands and islets, 11 of which compose about 95% of the total area and population. The majority of the Filipinos are descendants of Indonesians and Malays. Approximately 90% of the population are Christian with the majority of the remaining 10% being Moslems. In the 1960s, the annual population growth rate was roughly 3%, but it fell to 2.4% in the late 1970s and was still 2.4% in 1985. In 1970, President Marcos implemented an official family planning policy to reduce the high growth rate and thereby stimulate economic development. A population commission coordinates family planning efforts. Both the Spanish (1521-1898) and the United States (1898-1946) have ruled the Philippines with a brief occupation by the Japanese (1942-1945). The US assisted in the reconstruction of the economy following World War II and continues to maintain and operate military bases. Further, from 1946-1986, the Philippines has received $3.7 billion in economic and military assistance from the US. The government operated under a constitutional democracy from 1946-1972, but in 1972 President Marcos declared martial law. In 1981, martial law ended and Marcos called for a presidential election. After winning the election, he called for an amendment of the 1972 constitution making him, rather than the prime minister, the head of government. Even though martial law ended in 1981, the Marcos government retained its wide powers to arrest and detain anyone. In February 1986, popular support backed by a peaceful civilian-military uprising brought Corazon Aquino to the Presidency. In the mid 1980s a severe economic recession hit the Philippines with the real GNP growth rate ranging from -5.3%-0%. The Philippines have diplomatic relations with the south east Asian nations, many East Bloc nations, the US, China, Cuba, and the Soviet Union.

  18. Institutional economic analysis of vegetable production and marketing in northern Philippines: social capital, institutions and governance

    NARCIS (Netherlands)

    Milagrosa, A.

    2007-01-01

    This study examines vegetable production and marketing among indigenous communities in northernPhilippinesusing an institutional economics approach. It develops a framework that analyses the four levels of institutio

  19. Lateral Variations of Rayleigh-Wave Dispersions in the Philippine Sea Region

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    Wen-Yen Chang

    2007-01-01

    Full Text Available Fresh two-dimensional group and phase-velocity distribution maps of the Philippine Sea and surrounding areas are constructed using the tomographic inversion of more than 2500 Rayleigh-wave dispersion curves in the 20- to 120-sec period range. The results show that, for the periods used, both the group and phase-velocity variation patterns are very close to the geological and topographic features and are also consistent with previous studies of magnetic anomalies and evolutionary history of the Philippine Basin. On average, the periods of the peak group-velocity for the West Philippine Basin and the Oki-Daito ridge are about 40 and 32 sec for the Parece Vela and Shikoku basins. This implies that the lithosphere of the western Philippine Sea Basin is thicker, which is related to plate cooling and seafloor age. For most of the examined periods, the high velocity symmetry of the two sides of the Central Basin Ridge in the West Philippine Basin coincides well with the evolutionary history of the Philippine Sea Basin, and may be taken as additional evidence confirming the existence of the ridge. The group and phase-velocity distributions for periods longer than 80 sec are smooth throughout the whole Philippine Sea Basin, which implies that the upper mantle beneath the Philippine Sea Basin is nearly homogeneous at depths of 100 - 200 km. Moreover, the group and phase velocities in the region of the East Volcano Belt and Active Marginal Basin remain almost constant in the 36- to 80-sec period range, which indicates that the boundary between the lithosphere and asthenosphere is probably not obvious in this area.

  20. Underwater Acoustic Propagation in the Philippine Sea: Intensity Fluctuations

    Science.gov (United States)

    White, Andrew W.

    In the spring of 2009, broadband transmissions from a ship-suspended source with a 284 Hz center frequency were received on a moored and navigated vertical array of hydrophones over a range of 107 km in the Philippine Sea. During a 60-hour period over 19 000 transmissions were carried out. The observed wavefront arrival structure reveals four distinct purely refracted acoustic paths: one with a single upper turning point near 80 m depth, two with a pair of upper turning points at a depth of roughly 300 m, and one with three upper turning points at 420 m. Individual path intensity, defined as the absolute square of the center frequency Fourier component for that arrival, was estimated over the 60-hour duration and used to compute scintillation index and log-intensity variance. Monte Carlo parabolic equation simulations using internal-wave induced sound speed perturbations obeying the Garrett-Munk internal-wave en- ergy spectrum were in agreement with measured data for the three deeper-turning paths but differed by as much as a factor of four for the near surface-interacting path. Estimates of the power spectral density and temporal autocorrelation function of intensity were attempted, but were complicated by gaps in the measured time-series. Deep fades in intensity were observed in the near surface-interacting path. Hypothesized causes for the deep fades were examined through further acoustic propagation modeling and analysis of various available oceanographic measurements.

  1. Spatial-temporal patterns and driving mechanisms of semiannual variations in the Philippine Sea

    Science.gov (United States)

    Zhao, Jun; Li, Yuanlong; Wang, Fan; Zhai, Fangguo; Yu, Xiaolin

    2012-10-01

    Satellite altimetric sea surface height (SSH) measurements from 1992 through 2010 are used to explore the oceanic semiannual variations in the Philippine Sea (PS). Pronounced semiannual SSH variations are detected within two zonal bands. One lies east of Luzon Strait (19°-22°N) in the northern PS, while the other is southeast of Mindanao coast (4°-7°N) in the southern PS. In the two near-coast boxes where semiannual harmonic amplitude exceeds 4 cm, the northern box (127°-133°E, 19°-22°N) and the southern box (127°-133°E, 4°-7°N), semiannual changes contribute considerably to the total annual SSH variance by 12% and 17%, respectively. Despite prominent SSH variability, the bifurcation latitude of the North Equatorial Current (NBL) exhibits weak fluctuations with a peak-to-peak difference of only 0.3° on semiannual time scale. While the in-phase annual SSH variations between the two boxes work together to enhance annual NBL changes, their out-of-phase semiannual SSH variations offset each other in driving the NBL displacements. Further analysis with a 11/2-layer reduced-gravity model forced by ECMWF wind stress reveals that the observed semiannual SSH variations are primarily driven by local wind forcing in the far western Pacific. Rossby wave signals propagating from the eastern/central Pacific contribute much less due to along-path dispersion and cancellation. Semiannual signals of wind field in the northern PS reflect mainly the semiannual changes of the Asian Monsoon system, while those in the southern PS arise from the combined effects of Monsoon transition and the annual migration of the intertropical convergence zone (ITCZ).

  2. Sedimentary processes and development of the Zenisu deep-sea channel, Philippine Sea

    Institute of Scientific and Technical Information of China (English)

    WUShiguo; SakamotoIzumi

    2003-01-01

    Zenisu deep-sea channel originated from a volcanic arc region, Izu-Ogasawara Island Arc, and vanished in the Shikoku Basin of the Philippine Sea. According to the swath bathymetry, the deep-sea channel can be divided into three segments. They are Zenisu canyon, E-W fan channel and trough-axis channel. A lot of volcanic detritus were deposited in the Zenisu Trough via the deep-sea channel because it originated from volcanic arc settings. On the basis of the swath bathymetry, submersible and seismic reflection data, the deposits are characterized by turbidite and debrite deposits as those in the other major deep-sea channels. Erosion or few sediments were observed in the Zenisu canyon,whereas a lot of turbidites and debrites occurred in the E-W channel and trough axis channel. Cold seep communities,active fault and fluid flow were discovered along the lower slope of the Zenisu Ridge. Vertical sedimentary sequences in the Zenisu Trough consist of the four post-rift sequence units of the Shikoku Basin, among which Units A and B are two turbidite units. The development of Zenisu canyon is controlled by the N-S shear fault, the E-W fan channel is related to the E-W shear fault, and the trough-axis channel is related to the subsidence of central basin.

  3. Sedimentary processes and development of the Zenisu deep-sea channel, Philippine Sea

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Zenisu deep-sea channel originated from a volcanic arc region, Izu-Ogasawara Island Arc, and vanished in the Shikoku Basin of the Philippine Sea. According to the swath bathymetry, the deep-sea channel can be divided into three segments. They are Zenisu canyon, E-W fan channel and trough-axis channel. A lot of volcanic detritus were deposited in the Zenisu Trough via the deep-sea channel because it originated from volcanic arc settings. On the basis of the swath bathymetry, submersible and seismic reflection data, the deposits are characterized by turbidite and debrite deposits as those in the other major deep-sea channels. Erosion or few sediments were observed in the Zenisu canyon, whereas a lot of turbidites and debrites occurred in the E-W channel and trough axis channel. Cold seep communities, active fault and fluid flow were discovered along the lower slope of the Zenisu Ridge. Vertical sedimentary sequences in the Zenisu Trough consist of the four post-rift sequence units of the Shikoku Basin, among which Units A and B are two turbidite units. The development of Zenisu canyon is controlled by the N-S shear fault, the E-W fan channel is related to the E-W shear fault, and the trough-axis channel is related to the subsidence of central basin.

  4. Investigation of a measles outbreak in Cordillera, northern Philippines, 2013

    Directory of Open Access Journals (Sweden)

    Paola Katrina Ching

    2016-07-01

    Full Text Available Introduction: Measles is a highly infectious viral illness that remains one of the leading causes of death among children worldwide. In the Philippines, decreasing routine vaccination coverage from 2007 to 2011 led to local measles outbreaks. A team investigated a measles outbreak reported in Cordillera of the Philippines in May 2013. Methods: Measles case data with symptom onset from 2 February to 27 May 2013 were obtained from official sources and verified on site. Data included age, sex, residential address, signs and symptoms and vaccination status. Active case-findings were also conducted for contacts of these cases. The living environments of the cases were investigated. A survey was conducted with the cases and caregivers to understand their knowledge and attitudes about measles. Results: There were 50 measles cases identified with an age range from six months to 32 years (median: 16 years. Thirty-two were male (64%. Twenty (40% were hospitalized with one death. Thirty-two (64% cases were laboratory confirmed, and 36 (72% received a single dose of measles vaccine. Overcrowded living environments were observed among many cases. The majority of respondents (46/48, 96% knew about measles, but there were misconceptions about the cause of measles and how it can be prevented and managed. Conclusion: This measles outbreak occurred in an area with low immunization coverage. Achieving 95% measles immunization coverage and strengthening routine immunization strategies to address high-risk populations are recommended. Also, we recommend health education campaigns to include components that address misconceptions about measles.

  5. Investigation of a measles outbreak in Cordillera, Northern Philippines, 2013

    Science.gov (United States)

    Zapanta, Ma Justina; de los Reyes, Vikki Carr; Tayag, Enrique; Magpantay, Rio

    2016-01-01

    Introduction Measles is a highly infectious viral illness that remains one of the leading causes of death among children worldwide. In the Philippines, decreasing routine vaccination coverage from 2007 to 2011 led to local measles outbreaks. A team investigated a measles outbreak reported in Cordillera of the Philippines in May 2013. Methods Measles case data with symptom onset from 2 February to 27 May 2013 were obtained from official sources and verified on site. Data included age, sex, residential address, signs and symptoms and vaccination status. Active case-findings were also conducted for contacts of these cases. The living environments of the cases were investigated. A survey was conducted with the cases and caregivers to understand their knowledge and attitudes about measles. Results There were 50 measles cases identified with an age range from six months to 32 years (median: 16 years). Thirty-two were male (64%). Twenty (40%) were hospitalized with one death. Thirty-two (64%) cases were laboratory confirmed, and 36 (72%) received a single dose of measles vaccine. Overcrowded living environments were observed among many cases. The majority of respondents (46/48, 96%) knew about measles, but there were misconceptions about the cause of measles and how it can be prevented and managed. Conclusion This measles outbreak occurred in an area with low immunization coverage. Achieving 95% measles immunization coverage and strengthening routine immunization strategies to address high-risk populations are recommended. Also, we recommend health education campaigns to include components that address misconceptions about measles. PMID:27766180

  6. A review of soils and crops in the Bukidnon Highlands of Northern Mindanao, The Philippines

    OpenAIRE

    Dejarme-Calalang, GM.; Colinet, G.

    2014-01-01

    Introduction. This article reviews soil and crop production information from Bukidnon, Northern Mindanao, the Philippines. It focuses on the parent materials involved in forming Bukidnon soils, clay forming minerals, soil classification, types and location distribution, physico-chemical characteristics, soil potentialities and constraints, and the yields of the major crops. Literature. The information discussed was gathered from on-line journals, a compilation of agricultural research reports...

  7. Strike-slip tectonics within the northernmost Philippine Sea plate in an arc-continent collisional setting

    Science.gov (United States)

    Gong, Wei; Jiang, Xiaodian; Guo, Yufan; Xing, Junhui; Li, Congying; Sun, Yang

    2017-09-01

    The geological processes in the northernmost Philippine Sea plate, which is bounded by the Suruga and Sagami troughs, are a typical example of an active collision zone. We attempt to illustrate the stress field through seismic estimations and geodetic analysis and propose the kinematic mode of the northernmost tip of the Philippine Sea plate. Seven events (M ≥ 4.0) are chosen for waveform inversion by the ISOLA software to distinguish the stress field. In particular, six of the chosen events, which exhibit strike-slip motion, are distributed in the eastern area, where few focal mechanisms have been reported by previous studies. According to the available focal mechanisms, strike-slip faults with similar P and T axes are widely distributed in the study area. The stress inversion suggests that the northern area is characterized by a NW-SE compression and a NE-SW extension stress regime, although some spatial differences exist. As indicated by an analysis of the geodesy, epicenters, focal mechanisms, gravity anomalies and velocity structure, the deformation in the northernmost tip is mainly accommodated by several conjugate strike-slip fault systems with steep dips that center on the Izu volcanic line. Generally, the maximum principal stress of the kinematics is derived from the collision between the Philippine Sea plate and Central Japan. Because of the different subduction angles, rates and directions of the down-going plate, diverging slab-pull forces along the Suruga and Sagami troughs may be causing the NE-NNE extension in most of the areas that are bounded by the two troughs. The extension propagates southwards along the Izu volcanic line and reaches the area adjacent to Miyake-jima.

  8. Nitrite maxima in the Northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sankaranarayanan, V.N.; DeSousa, S.N.; Fondekar, S.P.

    There are 2 nitrite maxima in the Northern Arabian Sea, one at the thermocline depth and the other at depths between 300 and 500 m. The 2nd maximum is more prominent in the northeastern part of the Arabian Sea. The 1st maximum is associated...

  9. High prevalence of Schistosoma japonicum and Fasciola gigantica in bovines from Northern Samar, the Philippines.

    Directory of Open Access Journals (Sweden)

    Catherine A Gordon

    2015-02-01

    Full Text Available The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively and carabao (80.00% and 55.24%, respectively. The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively. The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines.

  10. Preliminary interpretation of satellite gravity and magnetic anomalies in the region of the Philippine Sea Plate

    Science.gov (United States)

    Chen, C.; Hu, Z.; Du, J.; Wang, Q.

    2011-12-01

    The Philippine Sea, situated in the northwestern Pacific, is one of the largest marginal seas on the Earth. Analysis of the Philippine Sea's intraplate fault tectonic systems and lithosphere's density and magnetism structures has a significant contribution to understanding not only the dynamic principles of subduction and convergence zones but also effect of plate subduction on back-arc area. It is also important to have cognizance for structure evolution of the ocean crust, the tension and extending progress of marginal sea basins and the mechanisms of geodynamics. Meanwhile, it can be a significant approach for researching the evolution of the East China Sea and the South China Sea. Using high-precision gravity forwarding method based on spatial domain in spherical coordinate, we have calculated the Bouguer gravity disturbance (BGD) in the Philippine Sea based on the ETOPO1 1 arc-minute topography & bathymetry data and the gravity field model EIGEN-6C. After removing the gravity effect of the sediments and deep abnormal materials, we make spherical cap harmonic analysis of the residual anomaly and obtain the topography of Moho and apparent-density's distribution of our study area by alternate iteration inversion method. Then, we calculate the distributions of the study area's magnetic anomalies based on the Earth magnetic model NGDC720, reduce to the pole of the study area's magnetic anomalies by the equivalent source method based on spherical prism magnetic forwarding, inverse the processed magnetic anomalies with spherical cap harmonic analysis to obtain the topography of Curie surface and the apparent magnetic susceptibility distribution. Finally, we divide the Philippine Sea block into tectonic units and derive the faults distributions through the analysis of gravity magnetic anomalies' linear characteristics. The results show that West Philippine Basin is divided by Central Basin Ridge into two block units, the tectonic trend of the north block is south

  11. Determination of Euler parameters of Philippine Sea plate and the inferences

    Institute of Scientific and Technical Information of China (English)

    ZANG; Shaoxian

    2002-01-01

    [1]Seno, T., The instantaneous rotation vector of the Philippine Sea Plate relative to the Eurasia plate, Tectonophysics, 1977, 42: 209-226.[2]Chase, C. G., Plate kinematics: The Americas, East Africa, and the rest of the world, Earth Planet Sci. Lett., 1978, 37: 355-368.[3]Minster, J. B., Jordan, T. H., Rotation vectors for the Philippine and Rivera plates, Eos. Trans. AGU, 1978, 60: 958.[4]Karig, D. E., Basin genesis in the Philippine Sea, Initial Rep. Deep Sea Drill Proj., 1975, 31: 857-879.[5]Ranken, B., Cardwell, R. K., Karig, D. E., Kinematics of the Philippine Sea plate, Tectonics, 1984, 3: 555-575.[6]Huchon, P., Comments on "Kinematics of the Philippine Sea plate" (eds. Branken, R. K., Cardwell, Karig, D. E.) Tecton-ics, 1986, 5: 165-168.[7]Weissel, J. K., Anderson, R. N., Is there Caroline plate? Earth Planet Sci. Lett., 1978, 41: 143-158.[8]Seno, T., Seth, S., Alice, E. G., A model for the motion of the Philippine Sea plate consistent with NUVEL-1 and Geological Data, J. Geophys. Res., 1993, 98: (B10): 17941-17948.[9]DeMets, C., Gordon, R. G., Argus, D. F. et al., Current plate motions, Geophys. J. Intel., 1990, 101: 425-478.[10]Zhu, W. Y., Cheng, Z. Y., Xiong, Y. Q. et al., Preliminary results of measuring the crustal deformation in Qinghai-Xizang area using GPS technique, Scence in China, Ser. D, 1998, 41(3): 314-318.[11]Zhu, W. Y., Wang, X. Y., Cheng, Z. Y. et al., Crustal motion of Chinese mainland monitored by GPS, Science in China, Ser. D, 2000, 43(4): 394-400.[12]Seno, T., Moriyama, T., Stein, S. et al., Redetermination of the Philippine sea plate motion (abstract), EOS Trans. Am. Geophysics Res., 1987, 68: 1474.[13]Yu, S. B., Kuo, L. C., GPS observation of crustal deformation in the Taiwan-Luzon region, Geophysical Res. Lett., 1999, 26(7): 923-926.[14]Yu, S. B., Chen, H. Y., Kuo, L. C., Velocity field of GPS station in the Taiwan area, Tectonophysics, 1997, 274: 41-59.[15]Kato, T., Kotake

  12. Rayleigh-wave Tomography and Seismic Anisotropic Structures in the Region of the Philippine Sea

    Science.gov (United States)

    Lee, Hsin-Yu; Legendre, Cédric P.; Chang, Emmy T. Y.

    2016-04-01

    The Philippine Sea Plate (PSP) is surrounded by convergent boundaries, the Pacific plate is subducting beneath the PSP along the Izu-Bonin and Mariana trenches at the east, whereas the PSP is subducting beneath the Eurasian plate along the Nankai trough, Ryukyu trench and Philippine trench at the west. The PSP can be divided by three oceanic basins: the oldest West Philippine basin developing in 35-45 Ma in the west, and the Shikoku and Parece Vela basins in 15-30 Ma in the east. Previous studies show a large variety of the seismic anisotropy structures in the region of the PSP, which correspond different scenarios of tectonic evolution for this area. In this study, we analyze both isotropic and anisotropic Rayleigh-wave velocity structures of the PSP by means of two-station method. The earthquakes of magnitude (Mw) greater than 5.0 in-between the years 1998-2014 were acquired. Totally, 7914 teleseismic events are adopted to form the measurements of Rayleigh-wave dispersion curves along 467 station-pairs over the PSP. The measured dispersion curves are then inverted into the isotropic and azimuthally anisotropic (2ψ) velocity maps at different periods with the damped, lateral smoothing LSQR inversion. The inversion is framed by the triangular grids which knots are of 200 km spacing. The consequent velocity anomalies are referenced to the average of the phase velocity at the periods between 50 and 100 seconds. The resulting velocity anomalies show a consistent pattern with the locations of the sub-basins in the PSP at the periods of 50 and 60 sec, which can be considered to be the association of lithospheric velocity structure with basin ages. The positive velocity anomalies are seen in the West Philippine basin associating the relatively old lithosphere; whereas the negative anomalies are found in the Shikoku and Parece Vela basins which the lithospheric structures are relatively young. On the other hand, the resultant azimuthal anisotropy reveals an apparent

  13. Intensified Springtime Deep Convection over the South China Sea and the Philippine Sea Dries Southern China.

    Science.gov (United States)

    Li, Zhenning; Yang, Song; He, Bian; Hu, Chundi

    2016-07-27

    Springtime rainfall, accounting for 25-40% of the annual rainfall in southern China, exerts great agricultural and socioeconomic impacts on the region. In the recent decades, southern China has experienced a significant declining trend of precipitation in boreal spring. Meanwhile, precipitation has increased over the South China Sea and the Philippine Sea (SCS-PhS). This paper presents observational and modeling evidences suggesting that the intensified latent heating released by the convection over SCS-PhS leads to suppressed springtime rainfall over southern China. Moisture budget analysis indicates that the drying trend over southern China is due mainly to weakened convergence of moisture flux, which is controlled by a heat-induced anomalous overturning circulation reinforced by the convection over SCS-PhS. Further idealized simulations support the feature that the heat-induced overturning circulation and its corresponding anomalous cyclone can be well established in several days under the spring mean flow condition. Thus, this rapid dynamic process is associated with both the intraseasonal-to-interannual variations and the long-term change of the springtime rainfall over southern China.

  14. Intensified Springtime Deep Convection over the South China Sea and the Philippine Sea Dries Southern China

    Science.gov (United States)

    Li, Zhenning; Yang, Song; He, Bian; Hu, Chundi

    2016-07-01

    Springtime rainfall, accounting for 25-40% of the annual rainfall in southern China, exerts great agricultural and socioeconomic impacts on the region. In the recent decades, southern China has experienced a significant declining trend of precipitation in boreal spring. Meanwhile, precipitation has increased over the South China Sea and the Philippine Sea (SCS-PhS). This paper presents observational and modeling evidences suggesting that the intensified latent heating released by the convection over SCS-PhS leads to suppressed springtime rainfall over southern China. Moisture budget analysis indicates that the drying trend over southern China is due mainly to weakened convergence of moisture flux, which is controlled by a heat-induced anomalous overturning circulation reinforced by the convection over SCS-PhS. Further idealized simulations support the feature that the heat-induced overturning circulation and its corresponding anomalous cyclone can be well established in several days under the spring mean flow condition. Thus, this rapid dynamic process is associated with both the intraseasonal-to-interannual variations and the long-term change of the springtime rainfall over southern China.

  15. APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise and NPANL Support

    Science.gov (United States)

    2014-09-30

    APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise and NPANL Support Rex K. Andrew Principal...signals evolve during propagation through a dynamically-varying deep ocean, and how the oceanic ambient noise field varies throughout deep ocean...specifically the Philippine Sea. The second objective is to continue an 18-year long experiment utilizing the North Pacific Ambient Noise Laboratory to

  16. Methane in the South China Sea and the Western Philippine Sea

    Science.gov (United States)

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

    2017-03-01

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

  17. Coral-based Holocene sea level of Paraoir, western Luzon, Philippines

    Science.gov (United States)

    Siringan, Fernando P.; Shen, Chuan-Chou; Lin, Ke; Abigania, Maria Isabel T.; Gong, Shou-Yeh

    2016-06-01

    Shallow-water corals are crucial natural archives for reconstructing deglacial sea-level changes. However, significant discrepancies exist between sea-level records from different places. Here we present recently acquired 230Th-dated coral ages between 10,256 ± 50 yr BP and 6654 ± 29 yr BP (before 1950 AD) from Paraoir, western Luzon, Philippines to document deglacial sea-level rise of the western Pacific. The results indicate that the Paraoir reef started growing 10.3 kyr BP from about 29 m below present sea level, and reached 8 m below the PSL at 7.2 kyr BP. The Paraoir sea-level records are consistent with those of northwestern Luzon and the western Australia coast; both of which are coral-based records in continental or island arc settings. But sea levels of Luzon are significantly higher than those of Tahiti, a basaltic island on oceanic crust. We propose that the differences in sea level between the Philippine and Tahiti result from spatial variations of glacial isostatic adjustment of the two sites.

  18. Oceanography of the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.

    The euphotic zone of the northern Arabian Sea ranges from 20-60 m with an average depth of about 40 m. Surface temperatures range from 22.5 to 28.5 degrees C, increasing from north to south. At 1000 m, the temperature is about 15 degrees C lower...

  19. Two new species of Glyphocrangon (Decapoda: Caridea: Glyphocrangonidae) from the East China Sea and the Philippines.

    Science.gov (United States)

    Han, Qingxi; Li, Xinzheng

    2014-08-18

    The present paper reports two new species of Glyphocrangon (Crustacea, Caridea, Glyphocrangonidae) collected respectively from the East China Sea and the Philippines. G. singularis sp. nov., from the East China Sea, is similar to G. fimbriata Komai & Takeuchi, 1994 with the presence of fringe of setae on dactyl of the third to fifth pereopods, but differs from G. fimbriata by the rostrum shape and the armature on the carapace; G. denticulata sp. nov., from the Philippines, is similar to G. pugnax De Man, 1918 with the entire anterior third carina, but differs from G. pugnax by armatures of the antennal scaphocerite and carapace, the lengths of rostrum and the spines of fifth abdominal somite, and the colouration of carapace. 

  20. APL-UW Deep Water Propagation 2015-2017: Philippine Sea Data Analysis

    Science.gov (United States)

    2015-09-30

    commanded a halt to my ambient noise data collection in April 2014, pending a review of procedures involving scientist use of military acoustic system...March 2015, the remote DOS computer was determined to be dead. Two linux systems, based on the successful design deployed in the Philippine Sea...experiments, have been prepared and tested at APL. Replacement of the DOS system with one of the linux systems (the other is an in-house back-up) is scheduled

  1. North Pacific Acoustic Laboratory: Deep Water Acoustic Propagation in the Philippine Sea

    Science.gov (United States)

    2013-09-30

    relatively benign northeast and north central Pacific Ocean. During 2009–2011 the methods developed to study long-range, deep water broadband...These papers include results from the 2004–2005 NPAL experiment in the central North Pacific, in addition to results from the NPAL Philippine Sea...PERFORMANCE BY MAN” Award Universidad Autonoma de Baja California, Facultad de Ciencias Marinas (Ensenada, Mexico) XXI Student Congress (May 14–16, 2013) W. H

  2. Development of the Philippine Mobile Belt in northern Luzon from Eocene to Pliocene

    Science.gov (United States)

    Suzuki, Shigeyuki; Peña, Rolando E.; Tam, Tomas A.; Yumul, Graciano P.; Dimalanta, Carla B.; Usui, Mayumi; Ishida, Keisuke

    2017-07-01

    The origin of the Philippine Archipelago is characterized by the combination of the oceanic Philippine Mobile Belt (PMB) and the Palawan Continental Block (PCB). This paper is focused on the geologic evolution of the PMB in northern Luzon from Eocene to Pliocene. The study areas (northern Luzon) are situated in the central part of the PMB which is occupied by its typical components made up of a pre-Paleocene ophiolitic complex, Eocene successions, Eocene to Oligocene igneous complex and late Oligocene to Pliocene successions. Facies analysis of the middle Eocene and late Oligocene to early Pliocene successions was carried out to understand the depositional environment of their basins. Modal sandstone compositions, which reflect the basement geology of the source area, were analyzed. Major element geochemistry of sediments was considered to reconstruct the tectonic settings. The following brief history of the PMB is deduced. During the middle Eocene, the PMB was covered by mafic volcanic rocks and was a primitive island arc. In late Eocene to late Oligocene time, the intermediate igneous complex was added to the mafic PMB crust. By late Oligocene to early Miocene time, the PMB had evolved into a volcanic island arc setting. Contributions from alkalic rocks are detected from the rock fragments in the sandstones and chemical composition of the Zigzag Formation. During the middle Miocene to Pliocene, the tectonic setting of the PMB remained as a mafic volcanic island arc.

  3. A review of soils and crops in the Bukidnon Highlands of Northern Mindanao, the Philippines

    Directory of Open Access Journals (Sweden)

    Dejarme-Calalang, GM.

    2014-01-01

    Full Text Available Introduction. This article reviews soil and crop production information from Bukidnon, Northern Mindanao, the Philippines. It focuses on the parent materials involved in forming Bukidnon soils, clay forming minerals, soil classification, types and location distribution, physico-chemical characteristics, soil potentialities and constraints, and the yields of the major crops. Literature. The information discussed was gathered from on-line journals, a compilation of agricultural research reports published in Northern Mindanao, published theses, government data and reports, and books. Bukidnon has existing soil information that could be useful for assessing and monitoring soil fertility and in establishing a regional Land Information System (LandIS. Soils in the Province are classified according to Soil Order, Great Group and soil type under the USDA Soil Taxonomic Classification. Data on crop production yields are also available. Soil information is intended more for crop fertilization planning at the broader scale. Studies on geomorphopedology and the interactions of elements within the soil are scarce. The relationship between soil formation and its characteristics and plant responses is not discussed here. Conclusion. The recommendations arising from this study are: (1 to conduct in-depth geomorphopedological studies in marginal areas of undifferentiated soils, (2 to study the relationship between soil characteristics and crop responses including nutrient assimilation by plants, focusing on phosphorus (P, and (3 to develop a generic protocol and establish a LandIS for mountain areas that can be replicated in other areas in Mindanao, the Philippines.

  4. 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

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

    Data.gov (United States)

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

  6. Physical and underway data collected aboard the MELVILLE during cruise MGLN32MV in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2008-02-07 to 2008-02-28 (NCEI Accession 0155954)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155954 includes physical and underway data collected aboard the MELVILLE during cruise MGLN32MV in the Philippine Sea, South China Sea (Nan Hai) and...

  7. Chemical, optical and other data collected aboard the MELVILLE during cruise MV0902 in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2009-02-06 to 2009-02-23 (NODC Accession 0116957)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116957 includes chemical, optical and other data collected aboard the MELVILLE during cruise MV0902 in the Philippine Sea, South China Sea (Nan Hai)...

  8. Physical and underway data collected aboard the MELVILLE during cruise MGLN30MV in the Philippine Sea, South China Sea (Nan Hai) and Sulu Sea from 2007-11-30 to 2008-01-04 (NODC Accession 0098586)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0098586 includes physical and underway data collected aboard the MELVILLE during cruise MGLN30MV in the Philippine Sea, South China Sea (Nan Hai) and...

  9. Examination of Global Seismic Tomography Images and Sea-Surface Magnetic Field Anomaly Profiles in the West Philippine Basin for the Large Clockwise Rotation of the Philippine Sea Plate during the Last 55 Million Years

    Science.gov (United States)

    Choe, H.; Lee, S. M.

    2014-12-01

    The Philippine Sea Plate is thought to have undergone a 90° clockwise rotation during the last 55 million years. However, evidences for such an argument are rather circumstantial. For instance, paleomagnetic measurements for the large rotation are derived largely from Halmahera, Indonesia which is quite close to the plate boundary. It is thus possible that this region may have undergone local deformation separate from the main parts of the Philippine Sea Plate. In this study, we examine the global seismic tomography images of the mantle beneath the Philippine Sea Plate and the marine magnetic field anomaly data at the sea surface from the West Philippine Basin to see whether they agree with the presumed motion of the Philippine Sea Plate. Our comparison between the plate reconstruction and global tomography suggests that the rotation of Philippine Sea Plate may not have been continuous but instead experienced a temporal break at around 32 Ma. The exact nature of this pause is uncertain, but it may be related to a sudden change in the configuration of subduction systems. A detail comparison with recent results from IODP Legs 350 and 351 is therefore necessary, including a search for a change in the depositional style of basin sediment. We also examined the detailed the shape of magnetic anomalies (such as skewness) and compare them with the previous model by allowing the magnetization to have direction corresponding to that during the opening of the West Philippine Basin. At this moment, it is too early to tell if the sudden change at around 32 Ma or other inferred breaks can be seen in the magnetic profiles as well.

  10. Distributions and sea-to-air fluxes of nitrous oxide in the South China Sea and the West Philippines Sea

    Science.gov (United States)

    Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto V.; DelValls, T. Angel; Lai, Chao-Ming; Chen, Ting-Yu

    2016-09-01

    Approximately 600 water samples from the South China Sea (SCS) and 250 water samples from the West Philippines Sea (WPS) were collected during seven cruises from August 2003 to July 2007 to determine nitrous oxide (N2O) distributions between the surface and a maximum depth of 4250 m. In the SCS, the average surface N2O concentration exceeded the atmospheric equilibrium concentration (on average 132±23%); however in the WPS, the surface N2O concentration was lower than the atmospheric equilibrium concentration (on average 90±22%). The N2O concentration reached a maximum (~23 nmol L-1) in the WPS at 800-1000 m, and (~28 nmol L-1) at a shallower depth of around 600-800 m in the SCS, owing to vertical mixing and intensive upwelling in the SCS. In the SCS, the surface N2O concentration was 7.59±1.32 nmol L-1 and the calculated sea-to-air flux was 5.5±3.9 μmol m-2 d-1. The surface N2O concentration in the WPS, 5.19±1.26 nmol L-1, was lower than that in the SCS. The WPS is a sink for N2O and the calculated sea-to-air flux was -1.7±3.9 μmol m-2 d-1. The SCS emitted 19.3×106 mol d-1 N2O to the atmosphere and exported 8.5×106 mol d-1 N2O to the WPS during the wet season.

  11. Illegal logging in the Northern Sierra Madre Natural Park, the Philippines

    Directory of Open Access Journals (Sweden)

    Jan van der Ploeg

    2011-01-01

    Full Text Available Illegal logging is a threat to biodiversity and rural livelihoods in the Northern Sierra Madre Natural Park, the largest protected area in the Philippines. Every year between 20,000 and 35,000 cu. m wood is extracted from the park. The forestry service and municipal governments tolerate illegal logging in the protected area; government officials argue that banning an important livelihood activity of households along the forest frontier will aggravate rural poverty. However this reasoning underestimates the scale of timber extraction, and masks resource capture and collusive corruption. Illegal logging in fact forms an obstacle for sustainable rural development in and around the protected area by destroying ecosystems, distorting markets, and subverting the rule of law. Strengthening law enforcement and controlling corruption are prerequisites for sustainable forest management in and around protected areas in insular southeast Asia.

  12. Upper mantle structure of the Pacific and Philippine Sea plates revealed by seafloor seismic array observations

    Science.gov (United States)

    Isse, Takehi; Shiobara, Hajime; Suetsugu, Daisuke; Sugioka, Hiroko; Ito, Aki

    2016-04-01

    Seismic tomography studies have revealed the structure and dynamics of Earth's interior since the 1980s. However, the spatial resolution of the oceanic region is not good enough caused by sparse distribution of the seismic stations. The observations with broadband ocean-bottom seismographs (BBOBSs) since the 2000s enabled us to obtain seismic tomography models with higher spatial resolution. Our Japanese BBOBS group deployed more than 100 BBOBSs in the Pacific Ocean and obtained a high-resolution (300-500 km) three-dimensional shear wave velocity structure in the upper mantle beneath northwestern and south Pacific Ocean by using surface wave tomography technique. In the northwestern Pacific Ocean, where the Pacific plate subducts beneath the Philippine Sea plate, we found that the shear wave structure in the Philippine sea plate is well correlated with the seafloor age in the upper 120 km, three separate slow anomalies in the mantle wedge at depth shallower than 100 km beneath the Izu-Bonin-Mariana arc, which have a close relationship with the three groups of frontal and rear arc volcanoes having distinct Sr, Nd, and Pb isotope ratios, and that the Philippine Sea plate, which is a single plate, shows very large lateral variations in azimuthal and radial anisotropies compared with the Pacific plate. In the South Pacific Ocean, where midplate hotspots are concentrated, we found that the localized slow anomalies are found near hotspots in the upper mantle, estimated thickness of the lithosphere is about 90 km in average and is thinned by ~20 km in the vicinity of hotspots, which may represent thermal erosion due to mantle plumes.

  13. Return to Clark Air Force Base: Establishing Permanent Military Bases in the Philippines as part of the United States Grand Strategy in the South China Sea

    Science.gov (United States)

    2016-02-16

    the South China Sea for fishing and the area was a heavily traveled trade route that brought new cultures to the region from India and the Middle...states border the South China Sea: Taiwan, China, Vietnam, Malaysia , Indonesia and the Philippines. And they all view the South China Sea as a key...South China Sea fishing has become a major industry. China’s fishing industry alone reached over $1.6 billion while both Malaysia and the Philippines

  14. The Crustal Thickness of the Philippine Sea Plate Derived from Gravity Data

    Directory of Open Access Journals (Sweden)

    Horng-Yuan Yen

    2015-01-01

    Full Text Available We constructed a new free-air gravity anomaly map of the Philippine Sea Plate (PSP using ship-tracked gravity data from the National Geophysical Data Center (NGDC. Our results show that the isogals trend correlates well with the tectonic structures in the PSP. After removing the gravity induced by sea water from the free-air gravity data, we obtained the regional Bouguer gravity anomaly, which is later used to compute the Moho geometry in the PSP by applying the Parker-Oldenburg iterative method. Our results indicate that in the southern part of the West Philippine Basin (WPB the crustal thickness is nearly homogeneous with a value of about 5 km, which implies that the WPB is quite stable. The low-amplitude and near-zero free-air gravity anomalies clearly indicate that the whole WPB, except at trenches and island arcs, is nearly in a state of isostatic equilibrium. The average crustal thickness of the Palau Kyushu Ridge (PKR is more than 10 km. In the eastern PSP the crustal thickness gradually increases eastward. Our results also imply that a relatively thin and low density mantle exists beneath the Parece Vela Basin (PVB as a consequence of back-arc spreading and serpentinized upwells of the thin crustal thickness.

  15. Paleoproductivity evolution in the West Philippine Sea during the last 700 ka

    Institute of Scientific and Technical Information of China (English)

    TANG Zheng; LI Tiegang; CHANG Fengming; NAN Qingyun; LI Qing

    2013-01-01

    In order to reconstruct the paleoproductivity evolution history of the West Philippine Sea during the last 700 ka,the vertical gradient of Aδ13C in dissolved inorganic carbon (Aδ13C between those of foraminifera Pulleniatina obliquiloculata and Cibicidoides wuellerstorfi) and planktonic foraminiferal assemblages were analysed in piston Core MD06-3047 retrieved from the Benham Rise (east of the Luzon Island).Paleoproductivity evolution in the West Philippine Sea during the last 700 ka is closely related to glacial-interglacial cycles and precession-controlled insolation.Controlling factors of paleoproductivity could have been both thermocline fluctuations related with ENSO-like processes and eolian input associated with East Asian winter monsoon,and the former could have been the primary factor.A higher productivity and a shallower thermocline coeval with the occurrence of low CO2 concentrations in the EPICA Dome C icecore might indicate that biological export production in the low-latitude could act as a significant sink in the global carbon cycle,and modify atmospheric CO2 concentrations.Spectral analysis further reveals that the paleoproductivity is mainly controlled by thermocline fluctuations subjected to ENSO processes responding to processional variability of insolation.High coherences in eccentricity,obliquity and precession periods further revealing the close link between thermocline fluctuations,paleoproductivity and atmospheric CO2 levels.

  16. First records of the reef manta ray Manta alfredi in the Bohol Sea, Philippines, and its implication for conservation

    Directory of Open Access Journals (Sweden)

    Joshua Maniriniaina Rambahiniarison

    2016-12-01

    Full Text Available We report the occurrence of the reef manta ray Manta alfredi Krefft 1868 in the Bohol Sea, Philippines, based on photographic evidence from boat-based surveys and a fishery specimen. Despite previous anecdotal reports from the diving industry and over a century of extensive targeted fisheries for mobulid rays in the Philippines, it was not until recently that the species was first confirmed in the country at the Tubbataha Reefs Natural Park, Palawan. Our results confirm the presence of M. alfredi in the Visayas region of the Philippines, extending the current range for the species from the Sulu Sea over 600 km eastwards. Its presence in a region with an active mobulid fishery has important implications for the conservation and management of M. alfredi in the country. We highlight the need to understand the distribution of M. alfredi in the region and make management recommendations based on the present study.

  17. Spectral analysis of magnetic anomalies in and around the Philippine Sea

    Science.gov (United States)

    Tanaka, A.; Ishihara, T.

    2009-12-01

    Regional compilations of lithospheric structure from various methods and data and comparison among them are useful to understand lithospheric structure and the processes behind its formation and evolution. We present constraints on the regional variations of the magnetic thicknesses in and around the Philippine Sea. We used a new global magnetic anomaly data [Quesnel et al, 2009], which is CM4-corrected [Comprehensive Model 4; Sabaka et al., 2004], cleaned and leveled to clarify the three-dimensional crustal magnetic structure of the Philippine Sea. The Philippine Sea is one of the largest marginal seas of the world. The north-south-trending Kyushu-Palau Ridge divides it into two parts: the West Philippine Basin and the Daito Ridge province in the west and the Shikoku and Parece Vela Basins in the east. The age of the basins increases westward [Karig, 1971]. And, there are three ridges in the Daito Ridge province west of the Kyushu-Palau Ridge; the Oki-Daito, Daito Ridges and the Amami Plateau from south to north, and small basins among them. Two-dimensional spectral analysis of marine magnetic anomalies is used to estimate the centroid of magnetic sources (Zo) to constrain the lithospheric structure [Tanaka and Ishihara, 2008]. The method is based on that of Spector and Grant [1970]. Zo distribution of the Philippine Sea shows occurrence of shallow magnetic layer areas with approximately less than 10 km in the Shikoku Basin. It also shows variations in deep and shallow magnetic layer areas in the Amami-Daito Province. These patters correspond to spatial variations of the crustal thickness deduced from the three-dimensional gravity modeling [Ishihara and Koda, 2007] and acoustic basement structures [Higuchi et al., 2007]. These three spatial distributions are roughly consistent with each other, although they may contain some scatters and bias due to the different characteristics and errors. This two-dimensional spectral analysis method is based upon an assumption

  18. HELIUM, PARTICULATE ORGANIC CARBON and other data from HEIYO, KAIYO and other platforms in the NW Pacific, Philippine Sea and East China Sea from 1939-08-17 to 1988-09-27 (NCEI Accession 9000197)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A tape containing part of the annual exchange of chemical data from the Japan Oceanographic Data Center collected from East China Sea (Tung Hai), Philippine Sea, NW...

  19. Physical and underway data collected aboard the KILO MOANA during cruise KM0910 in the Philippine Sea and South China Sea (Nan Hai) from 2009-04-14 to 2009-05-04 (NODC Accession 0089592)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089592 includes physical and underway data collected aboard the KILO MOANA during cruise KM0910 in the Philippine Sea and South China Sea (Nan Hai)...

  20. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1204 in the Philippine Sea and South China Sea (Nan Hai) from 2012-04-24 to 2012-05-14 (NCEI Accession 0129849)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129849 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1204 in the Philippine Sea and South China Sea...

  1. Physical and underway data collected aboard the MELVILLE during cruise MGLN23MV in the Philippine Sea and South China Sea (Nan Hai) from 2007-07-18 to 2007-07-28 (NODC Accession 0098573)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0098573 includes physical and underway data collected aboard the MELVILLE during cruise MGLN23MV in the Philippine Sea and South China Sea (Nan Hai)...

  2. Physical and underway data collected aboard the MELVILLE during cruise MGLN22MV in the Philippine Sea and South China Sea (Nan Hai) from 2007-07-09 to 2007-07-15 (NODC Accession 0098571)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0098571 includes physical and underway data collected aboard the MELVILLE during cruise MGLN22MV in the Philippine Sea and South China Sea (Nan Hai)...

  3. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1007 in the Philippine Sea and South China Sea (Nan Hai) from 2010-06-01 to 2010-06-10 (NODC Accession 0089637)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089637 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1007 in the Philippine Sea and South China Sea (Nan...

  4. Physical and underway data collected aboard the MELVILLE during cruise MV0906 in the Philippine Sea and South China Sea (Nan Hai) from 2009-04-14 to 2009-05-01 (NODC Accession 0089608)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089608 includes physical and underway data collected aboard the MELVILLE during cruise MV0906 in the Philippine Sea and South China Sea (Nan Hai)...

  5. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1004 in the Philippine Sea and South China Sea (Nan Hai) from 2010-04-06 to 2010-04-07 (NODC Accession 0089634)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089634 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1004 in the Philippine Sea and South China Sea (Nan...

  6. Physical and underway data collected aboard the MELVILLE during cruise MV0904 in the Philippine Sea and South China Sea (Nan Hai) from 2009-03-22 to 2009-03-27 (NODC Accession 0089606)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089606 includes physical and underway data collected aboard the MELVILLE during cruise MV0904 in the Philippine Sea and South China Sea (Nan Hai)...

  7. Physical and underway data collected aboard the MELVILLE during cruise MGLN27MV in the Philippine Sea and South China Sea (Nan Hai) from 2007-10-22 to 2007-11-03 (NODC Accession 0098575)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0098575 includes physical and underway data collected aboard the MELVILLE during cruise MGLN27MV in the Philippine Sea and South China Sea (Nan Hai)...

  8. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1305 in the Philippine Sea and South China Sea (Nan Hai) from 2013-05-07 to 2013-05-16 (NCEI Accession 0132725)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0132725 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1305 in the Philippine Sea and South China Sea (Nan...

  9. Physical and underway data collected aboard the KILO MOANA during cruise KM0909 in the Philippine Sea and South China Sea (Nan Hai) from 2009-03-20 to 2009-04-09 (NODC Accession 0089676)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089676 includes physical and underway data collected aboard the KILO MOANA during cruise KM0909 in the Philippine Sea and South China Sea (Nan Hai)...

  10. Vertical Movements, Behavior and Habitat Utilization of Adult Yellowfin Tuna (Thunnus albacares) Tagged in West Philippine Sea, Mindoro Island, Philippines

    NARCIS (Netherlands)

    Macusi, Edison; Babaran, R.P.; Ingles, J.T.

    2015-01-01

    This paper describes the vertical movements, behavior and habitat utilization of an electronically tagged adult yellowfin tuna (Thunnus albacares) after 17 days of liberty in the Philippines based on analyses of 23,845 datapoints recorded from a recovered electronic popup tag. The exhaustive set pro

  11. Vertical Movements, Behavior and Habitat Utilization of Adult Yellowfin Tuna (Thunnus albacares) Tagged in West Philippine Sea, Mindoro Island, Philippines

    NARCIS (Netherlands)

    Macusi, Edison; Babaran, R.P.; Ingles, J.T.

    2015-01-01

    This paper describes the vertical movements, behavior and habitat utilization of an electronically tagged adult yellowfin tuna (Thunnus albacares) after 17 days of liberty in the Philippines based on analyses of 23,845 datapoints recorded from a recovered electronic popup tag. The exhaustive set

  12. Variation in macrofaunal communities of sea grass beds along a pollution gradient in Bolinao, northwestern Philippines.

    Science.gov (United States)

    Leopardas, Venus; Honda, Kentaro; Go, Gay Amabelle; Bolisay, Klenthon; Pantallano, Allyn Duvin; Uy, Wilfredo; Fortes, Miguel; Nakaoka, Masahiro

    2016-04-15

    This study examined the variation of macrofaunal communities in sea grass beds along a pollution gradient in Bolinao, northwestern Philippines. We established four stations and compared the diversity and abundance of macrofauna between them. The Shannon diversity index in the least polluted station was more than twice higher than that in the most polluted one. Abundance was more than thrice higher in the most polluted station. The species composition generally varied, with community difference explained largely by the predominance of the filter-feeding bivalve Gafrarium pectinatum and polychaete Capitella capitata. Species heterogeneity was reduced along the pollution gradient by approximately 19% from the least polluted to the most polluted station. This reduction indicates biodiversity alteration, which has a significant impact on ecosystem functioning. Aspects of species heterogeneity should be considered in environmental impact assessments and the management of coastal areas encountered with anthropogenic disturbances.

  13. Geometry and spatial variations of seismic reflection intensity of the upper surface of the Philippine Sea plate off the Boso Peninsula, Japan

    Science.gov (United States)

    Kono, Akihiro; Sato, Toshinori; Shinohara, Masanao; Mochizuki, Kimihiro; Yamada, Tomoaki; Uehira, Kenji; Shinbo, Takashi; Machida, Yuya; Hino, Ryota; Azuma, Ryousuke

    2017-07-01

    In the region off the Boso Peninsula, Japan, the Pacific plate is subducting westward beneath both the Honshu island arc and Philippine Sea plate, while the Philippine Sea plate is subducting northwestward beneath the Honshu island arc. These complex tectonic interactions have caused numerous seismic events occurred in the past. To better understand these seismic events, it is important to determine the geometry of the plate boundary, in particular the upper surface of the Philippine Sea plate. We conducted an active-source seismic refraction survey in July and August 2009 from which we obtained a 2-D P-wave velocity structure model along a 216-km profile. We used the velocity model and previously published data that indicate a P-wave velocity of 5.0 km/s for the upper surface of the subducting Philippine Sea plate to delineate its boundary with the overriding Honshu island arc. Our isodepth contours of the upper surface of the Philippine Sea plate show that its dip is shallow at depths of 10 to 15 km, far off the Boso Peninsula. This shallow dip may be a result of interference from the Pacific plate slab, which is subducting westward under the Philippine Sea plate. Within our survey data, we recognized numerous seismic reflections of variable intensity, some of which came from the upper surface of the Philippine Sea plate. An area of high seismic reflection intensity corresponds with the main slip area of the Boso slow slip events. Our modeling indicates that those reflections can be explained by an inhomogeneous layer close to the upper surface of the Philippine Sea plate.

  14. Recognising land rights for conservation? tenure reforms in the Northern Sierra Madre, The Philippines

    National Research Council Canada - National Science Library

    van der Ploeg, Jan; Aquino, DanteM; Minter, Tessa; van Weerd, Merlijn

    2016-01-01

    .... In this paper, we describe four conservation projects that specifically aimed to formalise land rights in the Philippines, a country widely seen as a model for the devolution of control over natural...

  15. Climate Change May Bring More Tainted Shellfish to Northern Seas

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160300.html Climate Change May Bring More Tainted Shellfish to Northern Seas ... must be monitored "in the light of ongoing climate change, especially in coastal areas most heavily affected by ...

  16. The History and Characteristics of the Mobulid Ray Fishery in the Bohol Sea, Philippines

    Science.gov (United States)

    Tull, Malcolm

    2016-01-01

    The fishery for mobulid rays, also known as devil rays, has been practiced in the Bohol Sea for over a century yet very little is known about its history and characteristics. This study provides the first detailed description of the mobulid ray fishery in the Bohol Sea, Philippines. It describes the history and evolution of the fishery from the 19th century to 2013. It characterizes the fishery based on the species targeted, gears used, the organization, catch distribution, processing, monetary value, and the market of its by-products. This paper also analyses the changes that occurred through time, the management of the fishery and the drivers of the fishery. A multi-disciplinary approach was employed by combining ethno-historical research methods and catch landing monitoring in four primary sites within the Bohol Sea. This fishery began as an artisanal fishery using sail and row boats equipped with harpoons and gaff hooks practiced in at least four coastal villages in Bohol, Camiguin and Limasawa. The fishing fleet has decreased since the beginning of the 20th century however, with the motorization of the fishery and shift to the use of gillnets, the extent of the fishing grounds and market of the products have expanded. Four species of mobulid rays are caught in the Bohol Sea: Manta birostris, Mobula japanica, Mobula thurstoni and Mobula tarapacana. A fifth species, targeted by a fishing community off Dinagat as an off-shoot of the Bohol fishery is most likely the Manta alfredi. Currently, the fishery for mobulids is centered in Bohol Province where it has been practiced longest. The monetary value of mobulids in this region has increased and the dependence of fishing communities for their livelihood is significant. The unique characteristics of this fishery and the socio-cultural context within which it operates merits a thorough investigation in order to design the appropriate management strategy. PMID:27575536

  17. A new tomographic image on the Philippine Sea Slab beneath Tokyo - Implication to seismic hazard in the Tokyo metropolitan region -

    Science.gov (United States)

    Hirata, N.; Sakai, S.; Nakagawa, S.; Ishikawa, M.; Sato, H.; Kasahara, K.; Kimura, H.; Honda, R.

    2012-12-01

    In central Japan, the Philippine Sea plate (PSP) subducts beneath the Tokyo metropolitan region. Devastating M8-class earthquakes occurred on the upper surface of the Philippine Sea plate (SPS), examples of which are the Genroku earthquake of 1703 (magnitude M=8.0) and the Kanto earthquake of 1923 (M=7.9), which had 105,000 fatalities. A M7 or greater (M7+) earthquake in this region at present has high potential to produce devastating loss of life and property with even greater global economic repercussions although it is smaller than the megathrust type M8-class earthquakes. This great earthquake is evaluated to occur with a probability of 70 % in 30 years by the Earthquake Research Committee of Japan. The M7+ earthquakes may occur either on the upper surface or intra slab of PSP. The Central Disaster Management Council of Japan estimates the next great M7+ earthquake will cause 11,000 fatalities and 112 trillion yen (1 trillion US$) economic loss at worst case if it occur beneath northern Tokyo bay with M7.3. However, the estimate is based on a source fault model by conventional studies about the PSP geometry. To evaluate seismic hazard due to the great quake we need to clarify the geometry of PSP and also the Pacific palate (PAP) that subducs beneath PSP. We identify those plates with use of seismic tomography and available deep seismic reflection profiling and borehole data in southern Kanto area. We deployed about 300 seismic stations in the greater Tokyo urban region under the Special Project for Earthquake Disaster Mitigation in Tokyo Metropolitan Area. We obtain clear P- and S- wave velocity (Vp and Vs) tomograms which show a clear image of PSP and PAP. A depth to the top of PSP, 20 to 30 kilometer beneath northern part of Tokyo bay, is about 10 km shallower than previous estimates based on the distribution of seismicity (Ishida, 1992). This shallower plate geometry changes estimations of strong ground motion for seismic hazards analysis within the Tokyo

  18. Tension in the South China Sea: Why the Philippines is Challenging China’s Improved Military Might

    Science.gov (United States)

    2013-12-01

    entering into the JMSU, Manila provided legitimacy to Chinese claims in the SCS, and Barry Wain points out that the Philippines even agreed to joint...25 Rosamond, “Surface Tension: Rivals Jostle in South China Sea.” 26 Sabater, “Palace: JMSU Worsens Spratlys Dispute.” 27 Barry Wain ...the United States. CRS Report RL32688. Washington, DC: Library of Congress, Congressional Research Service, 2006. Wain , Barry . “Manila’s Bungle in

  19. Gas seepage in the Northern Adriatic Sea

    Science.gov (United States)

    Matilde Ferrante, Giulia; Donda, Federica; Volpi, Valentina; Tinivella, Umberta

    2017-04-01

    In the Northern Adriatic Sea, the occurrence of gas seepage has been widely documented. However, the origin of seeping gas was not clearly constrained. Geophysical data with different scale of resolution, i.e. multichannel seismic profiles, CHIRP and morpho-bathymetry data collected in 2009 and 2014 by OGS reveal that several the gas-enriched fluid vents are deeply rooted. In fact, the entire Plio-Quaternary succession is characterized by widespread seismic anomalies represented by wipe-out zones and interpreted as gas chimneys. They commonly root at the base of the Pliocene sequence but also within the Paleogene succession, where they appear to be associated to deep-seated, Mesozoic-to-Paleogene faults. These chimneys originate and terminate at different stratigraphic levels; they also commonly reach the seafloor, where rock outcrops interpreted as authigenic carbonate deposits have been recognized. In places, gas is then capable to escape in the water column as shown by numerous gas flares. On going studies are addressed to: 1. re-examining the structural setting of the study area, in order to verify a possible structural control on chimney distribution and gas migration; 2. performing geochemical analysis on gas which have been sampled in some key emission points; 3. a quantitative analysis of some selected boreholes well logs (made available through the public VidePi database (www.videpi.com)) aimed to estimate the amount of gas present in sediments. This work presents the preliminary results regarding the latter aspect of our research. In a first instance, for each selected borehole the geophysical logs have been digitized. This procedure consists in a manual picking of curves, in a set system of reference. Static corrections for vertical offset are made at this stage. Logs are then divided by type and converted in common scales, amplifications and units. Every log is resampled in order to cut high frequencies not useful in the comparison with seismic data

  20. Provenance of a prominent sediment drift on the northern slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The sedimentation rate of the sediment drift in the southeast of Dongsha Islands is as high as 49 cm/ka in the last 1.05 Ma. Although the sedimentation rate changes with time, the con tents of rare elements of the sediments remain almost the same, indicating that the source area of the sediments has been constant with time. On the triangular diagrams of La-Th-Sc and Th-Sc-Zr/10, the samples from the southeast of Dongsha Islands fall within the continental island arc field, overlapping the samples from Taiwan, while the samples from the Pearl River, those from the west of the Philippines that contain volcanic material, are separated from them. This indicates that the sediments from the southeast of Dongsha Islands have a close relationship to those from Taiwan in terms of provenance. In fact, the sediments on the northern slope of the South China Sea were derived from northeast direction, as well as from Taiwan, most probably transported from Taiwan through Penghu channel into the South China Sea. The terrigenous part of the deep-sea sediments in the north of the South China Sea was provided by different sources.

  1. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1010 in the Philippine Sea and South China Sea (Nan Hai) from 2010-07-31 to 2010-08-12 (NCEI Accession 0129832)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129832 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1010 in the Philippine Sea and South China...

  2. Physical and underway data collected aboard the KILO MOANA during cruise KM0908 in the North Pacific Ocean, Philippine Sea and South China Sea (Nan Hai) from 2009-02-27 to 2009-03-17 (NODC Accession 0089660)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089660 includes physical and underway data collected aboard the KILO MOANA during cruise KM0908 in the North Pacific Ocean, Philippine Sea and South...

  3. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1014 in the East China Sea (Tung Hai) and Philippine Sea from 2010-10-12 to 2010-10-23 (NODC Accession 0089642)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089642 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1014 in the East China Sea (Tung Hai) and Philippine...

  4. Paleoenvironments Recorded in a New-Type Ferromanganese Crust from the East Philippine Sea

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We attempt to recover the paleoenvironments recorded in the accretion of a typical newtype hydrogenetic ferromanganese crust from the deep water areas of the East Philippine Sea. From detailed geochemical and U-series chronological studies, analysis of major and minor dements performed by X-ray fluorescence spectrometry (XRF) and inductively coupled plasma-mass spectrometer (ICPMS), three major accretion periods and corresponding paleoenvironments can be ascertained. The first period is a faster accretion period in the terminal Late Miocene to the Early Pliocene with looser structure and higher volcanic detritus content, corresponding to the active Antarctic bottom waters and depressed temperature from the intermediate Middle Miocene to the Early Pliocene. The second period is a pulse of pelagic clay deposition at the Early to Middle Pliocene, reflecting the shrinkage of the Antarctic bottom waters and the global temperature elevation of this period. The third period is a slower accretion period from the Middle Pliocene, which indicates the more violent activity of Antarctic bottom waters once again and more depressed temperature than the first period, facilitating the accretion of a more compact and pure ferromanganese zone. The paleoceanographic histories of these studied areas had not been made clear in previous research.

  5. China’s Potential for Economic Coercion in the South China Sea Disputes: A Comparative Study of the Philippines and Vietnam

    Directory of Open Access Journals (Sweden)

    Madhu Sudan Ravindran

    2012-01-01

    Full Text Available With tensions rising in the South China Sea, China’s use of its economic leverage over Southeast Asian countries has recently come into focus. With increasing economic and trade ties between China and Southeast Asia, the question being asked is whether China can successfully impose economic sanctions to gain policy concessions in the South China Sea disputes. This paper examines China’s relations with the Philippines and Vietnam and analyses the possibility of a successful economic sanction by China against these two countries in future disputes. The article concludes that Vietnam may be more vulnerable economically to Chinese sanctions than the Philippines. However, political factors would offset that vulnerability in the case of Vietnam and amplify it in the case of the Philippines, making the Philippines more likely to concede to modest political demands.

  6. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

    Science.gov (United States)

    Brown, Rafe M.; Siler, Cameron D.; Oliveros, Carl. H; Welton, Luke J.; Rock, Ashley; Swab, John; Weerd, Merlijn Van; van Beijnen, Jonah; Jose, Edgar; Rodriguez, Dominic; Jose, Edmund; Diesmos, Arvin C.

    2013-01-01

    Abstract We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study. PMID:23653519

  7. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range.

    Science.gov (United States)

    Brown, Rafe M; Siler, Cameron D; Oliveros, Carl H; Welton, Luke J; Rock, Ashley; Swab, John; Weerd, Merlijn Van; van Beijnen, Jonah; Jose, Edgar; Rodriguez, Dominic; Jose, Edmund; Diesmos, Arvin C

    2013-01-01

    We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.

  8. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

    Directory of Open Access Journals (Sweden)

    Rafe Brown

    2013-02-01

    Full Text Available We provide the first report on the herpetological biodiversity (amphibians and reptiles of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces, northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province, as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province, combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%. The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning. This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.

  9. The isotopic composition of dissolved cadmium in the water column of the West Philippine Sea

    Directory of Open Access Journals (Sweden)

    Shun-Chung eYang

    2014-11-01

    Full Text Available The dissolved concentration and isotopic compositions of cadmium (Cd in the seawater of the West Philippine Sea were determined. In general, Cd isotopic composition in the water column decreased with depth, with ε114/110Cd (ε114/110Cd = [(114Cd/110Cdsample / (114Cd/110CdNIST 3108 - 1]×10000 ranging from +7.2 to +10.1 in the top 60 m, from +4.8 to +5.1 between 100 and 150 m, peaking at +8.2 at 200 m, decreasing from +4.5 to +3.3 from 400 to 1000 m, and remaining constant at +3.0 from 1000 m and deeper. Different to a Rayleigh fractionation model, the isotopic composition and log scale concentrations of Cd do not exhibit a linear relationship. However, from the deep water to thermocline, the variations in Cd concentration and ε114/110Cd are relevant to the variations of temperature and salinity, indicating that water mixing is the dominant processes determining the concentration and isotopic composition in the interval. At 200 m where North Pacific Tropic Water dominates the water mass, the elevated ε114/110Cd could be linked to the composition in the upper portions of the water mass. In the top 150 m, the ε114/110Cd varies similarly to the phytoplankton community structures, implying that Cd uptake by various phytoplankton species may be associated with the isotopic variation. However, the effects of atmospheric inputs to the ε114/110Cd in the surface water cannot be excluded. A box model calculation is used to constrain the contributions of various processes to the Cd isotopes of surface water, and the results indicate that the Cd concentration and isotopic composition in most of the water body of the region are controlled by physical mixing, while the effects of biological fractionation and atmospheric inputs are limited in the euphotic zone.

  10. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1103 in the East China Sea (Tung Hai), Philippine Sea and South China Sea (Nan Hai) from 2011-02-26 to 2011-02-28 (NCEI Accession 0132119)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0132119 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1103 in the East China Sea (Tung Hai), Philippine Sea...

  11. Insect drift over the northern Arabian Sea in early summer

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, S.C.; Kulshrestha, V.; Choubey, A.K.; Parulekar, A.H.

    Air borne insects, mostly carried by wind currents, were trapped over the northern Arabian Sea (16 degrees to 20 degrees N; 68 degrees to 72 degrees E), in the course of cruise No. 111, ORV Sagar Kanya (March 14 to April 7, 1996). A total of 2...

  12. Overview of 2010-2013 spring campaigns of Seven South East Asian Studies (7-SEAS) in the northern Southeast Asia

    Science.gov (United States)

    Lin, N.; Tsay, S.; Hsu, N. C.; Holben, B. N.; Anh, N.; Reid, J. S.; Sheu, G.; Chi, K.; Wang, S.; Lee, C.; Wang, L.; Wang, J.; Chen, W.; Welton, E. J.; Liang, S.; Sopajaree, K.; Maring, H. B.; Janjai, S.; Chantara, S.

    2013-12-01

    The Seven South East Asian Studies (7-SEAS) is a grass-root program and seeks to perform interdisciplinary research in the field of aerosol-meteorology and climate interaction in the Southeast Asian region, particularly for the impact of biomass burning on cloud, atmospheric radiation, hydrological cycle, and regional climate. Participating countries include Indonesia, Malaysia, Philippines, Singapore, Thailand, Taiwan, Vietnam, and USA. A series of field experiments have been conducted during springtime biomass burning seasons in northern Southeast Asia, i.e., Dongsha Experiment in 2010, Son La Campaigns in 2011 and 2012, and BASELInE (Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles and Interactions Experiment) in 2013, respectively. Given an example, during 2010 Dongsha Experiment, a monitoring network for ground-based measurements was established, including five stations from northern Thailand and central Vietnam to Taiwan, with a supersite at the Dongsha Island (i.e. Pratas Island) in South China Sea (or East Sea). Aerosol chemistry sampling was performed for each station for characterizing the compositions of PM2.5/PM10 (some for TSP) including water-soluble ions, metal elements, BC/OC, Hg and dioxins. This experiment provides a relatively complete and first dataset of aerosol chemistry and physical observations conducted in the source/sink region for below marine boundary layer and lower free troposphere of biomass burning/air pollutants in the northern SE Asia. This presentation will give an overview of these 7-SEAS activities and their results, particularly for the characterization of biomass-burning aerosol at source regions in northern Thailand and northern Vietnam, and receptor stations in Taiwan, which is rarely studied.

  13. The Northern Bering Sea: An Arctic Ecosystem in Change

    Science.gov (United States)

    Grebmeier, J. M.; Cooper, L. W.

    2004-12-01

    Arctic systems can be rich and diverse habitats for marine life in spite of the extreme cold environment. Benthic faunal populations and associated biogeochemical cycling processes are influenced by sea-ice extent, seawater hydrography (nutrients, salinity, temperature, currents), and water column production. Benthic organisms on the Arctic shelves and margins are long-term integrators of overlying water column processes. Because these organisms have adapted to living at cold extremes, it is reasonable to expect that these communities will be among the most susceptible to climate warming. Recent observations show that Arctic sea ice in the North American Arctic is melting and retreating northward earlier in the season and the timing of these events can have dramatic impacts on the biological system. Changes in overlying primary production, pelagic-benthic coupling, and benthic production and community structure can have cascading effects to higher trophic levels, particularly benthic feeders such as walruses, gray whales, and diving seaducks. Recent indicators of contemporary Arctic change in the northern Bering Sea include seawater warming and reduction in ice extent that coincide with our time-series studies of benthic clam population declines in the shallow northern Bering shelf in the 1990's. In addition, declines in benthic amphipod populations have also likely influenced the movement of feeding gray whales to areas north of Bering Strait during this same time period. Finally a potential consequence of seawater warming and reduced ice extent in the northern Bering Sea could be the northward movement of bottom feeding fish currently in the southern Bering Sea that prey on benthic fauna. This would increase the feeding pressure on the benthic prey base and enhance competition for this food source for benthic-feeding marine mammals and seabirds. This presentation will outline recent biological changes observed in the northern Bering Sea ecosystem as documented in

  14. Small-island communities in the Philippines prefer local measures to relocation in response to sea-level rise

    Science.gov (United States)

    Laurice Jamero, Ma.; Onuki, Motoharu; Esteban, Miguel; Billones-Sensano, Xyza Kristina; Tan, Nicholson; Nellas, Angelie; Takagi, Hiroshi; Thao, Nguyen Danh; Valenzuela, Ven Paolo

    2017-08-01

    Most adaptation studies suggest that sea-level rise will lead to relocation as flooding worsens. Here we identified and evaluated potential adaptation strategies for adapting to sea-level rise, based on the experiences of four low-lying island communities in central Philippines that have experienced flooding during normal high tides since a 2013 earthquake that induced land subsidence. Coastal surveys, interviews and household questionnaires showed that island residents generally prefer in situ adaptation strategies rather than relocation to the mainland. These results are unexpected, particularly because a relocation programme has been developed by authorities on the mainland. Direct measurements during a flooding event indicate stilted housing as the most effective type of adaptation strategy. Many households have also raised their floors using coral stones, although this might inadvertently increase their vulnerability to typhoons and storm surges in the long-term.

  15. Seismic Structure Related to the Philippine Sea Plate Subduction beneath the Nansei-Shoto (Ryukyu) Trench

    Science.gov (United States)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.; Okada, C.

    2016-12-01

    The Philippine Sea plate (PHS) subduction develops a trench-arc-backarc system at the Nansei-Shoto island arc, southwest of Japan. Its backarc basin, the Okinawa Trough, is the only area around Japan where rifting has been observed at present. In the north of the Nansei-Shoto island arc, the PHS with large bathymetric highs (e.g. the Amami Plateau and the Daito Ridge) subducts approximately perpendicularly to the trench axis. In the southwest, the PHS obliquely subducts with linear seafloor topographies such as the Okinawa-Luzon fracture zone and the Gagua Ridge. We conducted multichannel seismic reflection and wide-angle seismic surveys to obtain inhomogeneous crustal structures related to such complex features of the plate subduction. The seismic lines that we shot across the Nansei-Shoto arc, consisted of two lines in the north and five lines in the southwest. We also shot two along-arc lines in the island arc and forearc areas in the southwest. Since we could not constrain the crustal structure deeper than 10 km precisely by a tomographic inversion of first arrival traveltimes, we carried out two-dimensional forward modeling using several reflection signals from the inner crust and Moho discontinuity. As a result, a middle crust with P wave velocity (Vp) of 5.9-6.5 km/s was detected between an upper and lower crust beneath the arc for all the seismic lines. However, the inner crustal structure largely differs depending on the survey lines. Distribution of low Vp forearc accretionary wedge also varies regionally along the trench axis. High Vp of 4-5 km/s within 2 km below the seafloor and Vp larger than 6 km/s just on the subducting plate boundary characterize the forearc at 125-127 E in the southwest region, which corresponds distinctive high free-air gravity anomaly. We could also obtain clear seismic images of the subducting bathymetric highs in the north and the Okinawa-Luzon fracture zone in the southwest.

  16. Investigation of Marine Magnetic Vector Anomalies in the Southern Ayu Trough, Southern Philippine Sea

    Science.gov (United States)

    Kim, S.; Lee, S.

    2001-12-01

    The Ayu Trough is a divergent margin, located at the boundary of the Philippine Sea and the Caroline Plates. Previous attempts to resolve the magnetic lineations of this region using total magnetic field have not been successful because it represents a case of east-west spreading center situated near the magnetic equator. The difficulty is compounded by the fact that the Ayu Trough is an ultra-slow-spreading center, which exhibits a complex history of evolution. As an attempt to get around the inherent ambiguity of total field measurement, a shipboard three-component magnetometer was employed during our recent cruise to the Ayu Trough along with proton precession magnetometer. This study examines the vector magnetic data collected in the south part of the Ayu Trough and compares them with tectonic features identified from other geophysical measurements. First, the magnetic field due to the ship was removed from the measured field. We then subtracted the International Geomagnetic Reference Field and the diurnal variation recorded at Guam observatory from our measurement. The amplitude of the north-south component anomalies is substantially less than that of other anomalies, which suggests that the general strike of magnetic lineations in this region is north-south. The magnetic boundary and their strike were estimated by assuming that the magnetic sources are two-dimensional. On the basis of its tectonic structure and interpretation of the total field anomaly pattern, the Ayu Trough can be divided into two sections with distance from the axis: the exterior (> 100 km from the axis) which shows evidence of rifted margin and the interior (appears to be useful in determining major boundaries, such as those between the exterior and interior sections in our area. Within the interior section of the Ayu Trough, however, the discrimination of magnetic boundaries was less successful. The lack of consistency of estimated strikes between track lines suggests that the seafloor

  17. Community-based technology transfer in rural aquaculture: the case of mudcrab Scylla serrata nursery in ponds in Northern Samar, Central Philippines.

    Science.gov (United States)

    Baticados, Didi B; Agbayani, Renato F; Quinitio, Emilia T

    2014-12-01

    Finding aquaculture development approaches to open up livelihood opportunities for the rural poor and in mainstreaming smallholder fish farmers to reduce poverty remain a challenge. This paper examines the community-based technology transfer mechanism of mudcrab nursery in ponds and its socioeconomic impacts on smallholder mudcrab growers in Northern Samar, Philippines. Results indicated that the technology is a viable enterprise done by a straight culture system method, which is the rearing of crablets from aquaculture technologies.

  18. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

    OpenAIRE

    2013-01-01

    Abstract We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historica...

  19. Climate and sea level changes and the role of shelf morphology in recording in Sibuyan Sea Basin, Philippines during the last 14 kyBP

    Science.gov (United States)

    Lloren, R. B.; Siringan, F. P.

    2014-12-01

    In this study, we reconstruct changes in precipitation using geochemical and grain size proxies and we look at how shelf morphology can influence the nature of sedimentary record of climate and oceanographic events. A 9.6m long sediment core from Sibuyan Sea basin within the internal seas of the Philippines, was raised from a water depth of 1660m. It was analyzed using an XRF core scanner at 1 cm resolution. Grain size was determined using a laser particle analyzer. Thirteen AMS radiocarbon dates from bulk organics provide age control spanning back to 14 kyBP. Overall, the trends of precipitation proxies Ti, Al and Al/Ti follow the 10o N insolation curve. A 1.4 ky periodicity rides on this general trend. But a stepwise decrease of these precipitation proxies occur at about 9ka and 4ka. The former correpond to the melt water pulse 1-c rapid sea level rise of about 15m while the latter correlates time-wise to a period of aridification. The Younger Dryas period, ca. 12.9-11.6 ka, another known dry period, does not show a shift or decrease in sediment input. Similarly, MWP -1B does no register a distinct signal in the core. The insensitivity of the core in reflecting the older climate and sea level events is attributed to the steep morphology of the sea floor where shoreline translations took place during the earlier sea level events; with a steeper sea floor, sediment sequestration near the shoreline will be low and therefore the basin will not feel much change in sediment input. For the younger climate and sea level events, the shoreline positions were already adjacent to sea floor with relatively gentler gradient where sediment sequestration is greater and where a sea level rise of a certain magnitude will translate the shoreline much farther.

  20. Sea level rise projections for northern Europe under RCP8.5

    OpenAIRE

    Grinsted, A.; Jevrejeva, S.; R. E. M. Riva; D. Dahl-Jensen

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the British Isles, the Baltic Sea, and the North Sea. The input to the regional sea level projection is a probabilistic projection of the major components of the global sea level budget. Local sea lev...

  1. Geochemical and isotopic characteristics of volcanic rocks from the northern East China Sea shelf margin and the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhigang; YU Shaoxiong; WANG Xiaoyuan; FU Yongtao; YIN Xuebo; ZHANG Guoliang; WANG Xiaomei; CHEN Shuai

    2010-01-01

    Volcanic rocks both from the northern East China Sea (NECS) shelf margin and the northern Okinawa Trough are subalkaline less aluminous,and lower in High Field Strength Elements (HFSE).These rocks are higher in Large Ion Lithophile Elements (LILE),thorium and uranium contents,positive lead anomalies,negative Nb-Ta anomalies,and enrichment in Light Rare Earth Elements (LREE).Basalts from the NECS shelf margin are akin to Indian Ocean Mid-Ocean Ridge Basalt (MORB),and rhyolites from the northern Okinawa Trough have the highest 207Pb/204Pb and 208Pb/204Pb ratios.The NECS shelf margin basalts have lower 87Sr/86Sr ratios,εNd and σ18O than the northern Okinawa Trough silicic rocks.According to 40K-40Ar isotopic ages of basalts from the NECS shelf margin,rifting of the Okinawa Trough may have been active since at least 3.65-3.86 Ma.The origin of the NECS shelf margin basalt can be explained by the interaction of melt derived from Indian Ocean MORB-like mantle with enriched subcontinental lithosphere.The basalts from both sides of the Okinawa Trough may have a similar origin during the initial rifting of the Okinawa Trough,and the formation of basaltic magmas closely relates to the thinning of continental crust.The source of the formation of the northern Okinawa Trough silicic rocks was different from that of the middle Okinawa Trough,which could have been generated by the interaction of basaltic melt with an enriched crustal component.From the Ryukyu island arc to East China,the Cenozoic basalts have apparently increasing trends of MgO contents and ratios of LREE to Heavy Rare Earth Elements (HREE),suggesting that the trace element variabilities of basalts may have been influenced by the subduction of the Philippine Sea plate,and that the effects of subduction of the Philippine Sea plate on the chemical composition of basaltic melts have had a decreasing effect from the Ryukyu island arc to East China.

  2. The El Salvador and Philippines Tsunamis of August 2012: Insights from Sea Level Data Analysis and Numerical Modeling

    Science.gov (United States)

    Heidarzadeh, Mohammad; Satake, Kenji

    2014-12-01

    We studied two tsunamis from 2012, one generated by the El Salvador earthquake of 27 August ( Mw 7.3) and the other generated by the Philippines earthquake of 31 August ( Mw 7.6), using sea level data analysis and numerical modeling. For the El Salvador tsunami, the largest wave height was observed in Baltra, Galapagos Islands (71.1 cm) located about 1,400 km away from the source. The tsunami governing periods were around 9 and 19 min. Numerical modeling indicated that most of the tsunami energy was directed towards the Galapagos Islands, explaining the relatively large wave height there. For the Philippines tsunami, the maximum wave height of 30.5 cm was observed at Kushimoto in Japan located about 2,700 km away from the source. The tsunami governing periods were around 8, 12 and 29 min. Numerical modeling showed that a significant part of the far-field tsunami energy was directed towards the southern coast of Japan. Fourier and wavelet analyses as well as numerical modeling suggested that the dominant period of the first wave at stations normal to the fault strike is related to the fault width, while the period of the first wave at stations in the direction of fault strike is representative of the fault length.

  3. The Mobile Teachers Profile Competencies Performance And Problems In The Department Of Education Division Of Northern Samar Philippines

    Directory of Open Access Journals (Sweden)

    Estrellita C. Pinca

    2015-08-01

    Full Text Available Abstract This study aimed to describe the profile of the mobile teachers assess their competencies determine the level of their performance and identify the problems they encountered from 2010-2014 in the Department of Education Division of Northern Samar Philippines. The descriptive evaluative research design was used. Questionnaires actual observation focus-group discussion and interview were utilized in gathering the data. All mobile teachers during the conduct of the study served as respondents. Others sources of information were the ALS Education supervisor ALS specialist the District supervisor barangay officials learners and completers. The performance rating given by the District supervisor was used as the basis in determining the work performance of the mobile teachers. The mobile teachers were young adults majorities were males educationally qualified but their formal training were inclined towards the conduct of formal classes. Several mobile teachers have pursued graduate studies geared towards administration and supervision. All were passers of the Licensure Examination for Teachers but were relatively young in service as mobile teachers. They have higher competence in the conduct of learning sessions and have very satisfactory work performance. Their major problems were lack of community-based instructional materials delayed release of travel allowance and absence of permanent room during the conduct of the learning sessions.

  4. Sea surface microplastics in Slovenian part of the Northern Adriatic.

    Science.gov (United States)

    Gajšt, Tamara; Bizjak, Tine; Palatinus, Andreja; Liubartseva, Svitlana; Kržan, Andrej

    2016-12-15

    Plastics are the most common material of marine litter and have become a global pollution concern. They are persistent in the environment where they gradually degrade into increasingly smaller particles-microplastics (MP). Our study presents results of sea-surface monitoring for MP in the Slovenian part of the Trieste Bay in the Northern Adriatic Sea. In 17 trawls conducted over a 20-month period we found a high average concentration of 406×10(3)MPparticles/km(2). Over 80% of the particles were identified as polyethylene. The significant variability of MP concentrations obtained on different sampling dates is explained by use of surface current maps and a recently developed Markov chain marine litter distribution model for the Adriatic Sea.

  5. Northern Arabian Sea Circulation Autonomous Research (NASCar) DRI: A Study of Vertical Mixing Processes in the Northern Arabian Sea

    Science.gov (United States)

    2015-09-30

    NASCar) DRI: A Study of Vertical Mixing Processes in the Northern Arabian Sea Ramsey R. Harcourt Applied Physics Laboratory University of...Sullivan of NCAR. Although its physical model is substantially similar to the LES used in prior research (e.g. Harcourt, 2008) the NCAR LES code...convective boundary layer statistics and structures generated by large-eddy simulation. Journal of the Atmospheric Sciences, 68, 2395-2415.

  6. Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.

    2013-03-01

    The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange variability depends on the behavior of the turbulent components of the surface flux (the sum of the latent and sensible heat). The large-scale composite sea level pressure (SLP) maps corresponding to turbulent flux minima and maxima show distinct atmospheric circulation patterns associated with each case. In general, extreme heat loss (with turbulent flux lower than −400 W m−2) over the northern Red Sea is observed when anticyclonic conditions prevail over an area extending from the Mediterranean Sea to eastern Asia along with a recession of the equatorial African lows system. Subcenters of high pressure associated with this pattern generate the required steep SLP gradient that enhances the wind magnitude and transfers cold and dry air masses from higher latitudes. Conversely, turbulent flux maxima (heat loss minimization with values from −100 to −50 W m−2) are associated with prevailing low pressures over the eastern Mediterranean and an extended equatorial African low that reaches the southern part of the Red Sea. In this case, a smooth SLP field over the northern Red Sea results in weak winds over the area that in turn reduce the surface heat loss. At the same time, southerlies blowing along the main axis of the Red Sea transfer warm and humid air northward, favoring heat flux maxima.

  7. Deformation of the Manazuru Knoll in Sagami Bay, central Japan, associated with subduction of the Philippine Sea plate

    Science.gov (United States)

    No, Tetsuo; Takahashi, Narumi; Miura, Seiichi; Yamashita, Mikiya; Kido, Yukari; Kodaira, Shuichi

    2014-12-01

    In January 2010, we conducted a multichannel seismic (MCS) reflection survey in Sagami Bay. As a result of this study, the deformation of the Manazuru Knoll, which is located near the plate boundary, was obtained. The Manazuru Knoll was formed by an asymmetric anticline, and the knoll has a geometry that is bent in a shape similar to that of a crank. The anticlinal axis, which was confirmed by MCS data, lies along the anticlinal axis shown on the bathymetric map, and the axis is bent first to the southeast and then to the east. It is estimated that the easternmost part of Manazuru Knoll has reached the vicinity of Miura Canyon. The offset of the strike of the anticline axis is approximately 7 km. A reverse fault related to the formation of Manazuru Knoll was identified in the southwestern side of the knoll. It is hypothesized that this reverse fault formed as a result of shortening of the structure, which occurred when the relative motion of the Philippine Sea plate was acting in a perpendicular direction close to the Manazuru Knoll. Therefore, it is estimated that the relative motion of the Philippine Sea plate was almost oblique or parallel to the anticlinal axis of Manazuru Knoll and that the eastern end of Manazuru Knoll was bent into a crank shape by strike-slip motion. This suggests that a part of Manazuru Knoll, located to the west of the plate boundary, moved to the northwest. Finally, it is assumed that the sediments of Miura Canyon and Sagami Knoll have been overlapping on the eastern end of Manazuru Knoll.

  8. Hydrological and biogeochemical Controls on Absorption and Fluorescence of Dissolved Organic Matter in the Northern South China Sea

    Science.gov (United States)

    Guo, Weidong; Wang, Chao; Li, Yan; Li, Yizhen; Song, Guodong; Wang, Lei; Cheng, Yuanyue

    2016-04-01

    Absorption and fluorescence of dissolved organic matter (DOM) were investigated in the northern South China Sea (SCS) and adjacent Kuroshio section of the West Philippine Sea (WPS). Two humic-like (C1, C2) and three protein-like (C3-C5) fluorescent components were identified using parallel factor analysis (PARAFAC). chromophoric DOM (CDOM) and fluorescent DOM (FDOM) in the northern SCS showed similar distribution patterns to the adjacent Kuroshio section and global open ocean, yet exhibited higher values in the whole water column. An isopycnal mixing model was adopted to quantify the difference in CDOM and FDOM in the euphotic zone between the northern SCS and WPS. Results showed that CDOM and humic-like FDOM were mainly modulated by Kuroshio intrusion, while protein-like FDOM were more affected by biological activities. At mid-depth, significant linear relationships between a350, C1, C2 and apparent oxygen utilization (AOU) suggested that CDOM and humic-like FDOM were produced in situ coupled to remineralization of biogenic sinking particle. Excess humic-like FDOM in the intermediate water of northern SCS were determined and more proportion of high molecular weight organic carbon was exported to the open ocean interior. In addition, regional distribution patterns of CDOM and FDOM were also tuned by mesoscale processes in the northern SCS. Different CDOM and FDOM components in the euphotic zone have apparently different responses for changes of biological activity and vertical mixing driven by eddies. Moreover, cold eddy could capture more sinking particles and finally increase the accumulation of bio-refractory CDOM and humic-like FDOM in the dark ocean. Finally, we demonstrated that the ratio of two humic-like FDOM (C1:C2, or peak C:M) may be a good indicator of water mixing, evolution of mesoscale eddies, photochemistry in the upper water and remineralization in the deeper layer.

  9. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the East China Sea (Tung Hai) and Philippine Sea from 1996-06-20 to 1996-07-15 (NODC Accession 0115023)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115023 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the East China Sea (Tung Hai) and Philippine Sea...

  10. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from OCEAN RESEARCHER I in the Philippine Sea and South China Sea from 1991-07-08 to 1991-07-12 (NCEI Accession 0143948)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0143948 includes discrete sample and profile data collected from OCEAN RESEARCHER I in the Philippine Sea and South China Sea (Nan Hai) from...

  11. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1412 in the North Pacific Ocean and Philippine Sea from 2014-10-29 to 2014-11-23 (NCEI Accession 0138180)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138180 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1412 in the North Pacific Ocean and Philippine Sea...

  12. Physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN274 in the North Pacific Ocean and Philippine Sea from 2012-01-25 to 2012-02-21 (NODC Accession 0104371)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104371 includes physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN274 in the North Pacific Ocean and Philippine Sea...

  13. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1606 in the Philippine Sea from 2016-05-19 to 2016-05-29 (NCEI Accession 0156116)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0156116 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1606 in the Philippine Sea from 2016-05-19 to...

  14. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1203 in the Indian Ocean and Philippine Sea from 2012-04-09 to 2012-04-21 (NCEI Accession 0138177)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138177 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1203 in the Indian Ocean and Philippine Sea from...

  15. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1105 in the Philippine Sea from 2011-03-24 to 2011-04-16 (NCEI Accession 0129834)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129834 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1105 in the Philippine Sea from 2011-03-24 to...

  16. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1403 in the Philippine Sea from 2014-04-14 to 2014-04-19 (NCEI Accession 0133629)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0133629 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1403 in the Philippine Sea from 2014-04-14 to...

  17. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1012 in the Philippine Sea from 2010-09-12 to 2010-09-17 (NODC Accession 0089640)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089640 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1012 in the Philippine Sea from 2010-09-12 to...

  18. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from RYOFU MARU in the Philippine Sea from 1992-02-10 to 1992-02-17 (NCEI Accession 0143943)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0143943 includes discrete sample and profile data collected from RYOFU MARU in the Philippine Sea from 1992-02-10 to 1992-02-17. These data include...

  19. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the OCEAN RESEARCHER I in the Philippine Sea from 1990-10-11 to 1990-10-15 (NODC Accession 0115600)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115600 includes chemical, discrete sample, physical and profile data collected from OCEAN RESEARCHER I in the Philippine Sea from 1990-10-11 to...

  20. Physical and profile data collected aboard the ROGER REVELLE during cruise RR1308 in the Philippine Sea from 2013-06-12 to 2013-06-26 (NCEI Accession 0132726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0132726 includes physical and profile data collected aboard the ROGER REVELLE during cruise RR1308 in the Philippine Sea from 2013-06-12 to...

  1. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the OCEAN RESEARCHER I in the Philippine Sea from 1991-06-26 to 1991-07-04 (NODC Accession 0115598)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115598 includes chemical, discrete sample, physical and profile data collected from OCEAN RESEARCHER I in the Philippine Sea from 1991-06-26 to...

  2. Temperature, salinity, and nutrient profiles, wave, and meteorological data from three cruises in the Northwest Pacific, the Southwest Pacific, and the Philippine Sea from 1965-11-30 to 1980-08-11 (NODC Accession 0000122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, meteorological, and nutrient profiles data were collected using bottle casts from the OSHORO MARU and RYOFU MARU in Philippines Sea and Pacific Ocean...

  3. Temperature profile data collected using BT and XBT from NOAA Ship RESEARCHER and other platforms in the Philippine Sea from 1971-10-06 to 1979-09-21 (NCEI Accession 8000151)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship RESEARCHER and other platforms in Philippine Sea from 06 October 1971 to 21 September...

  4. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the RYOFU MARU in the Philippine Sea from 1995-11-15 to 1995-11-30 (NODC Accession 0117669)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117669 includes chemical, discrete sample, physical and profile data collected from RYOFU MARU in the Philippine Sea from 1995-11-15 to 1995-11-30...

  5. Physical and other data from bottle and XBT casts from the PUSAN-852 and other platforms from the Philippine Sea from 17 January 1978 to 04 June 1988 (NODC Accession 8900142)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and other data from bottle and XBT casts from the PUSAN-852 and other platforms from the Philippine Sea. Data were collected by the Maritime Safety Agency;...

  6. Physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN232 in the Philippine Sea from 2009-04-02 to 2009-04-17 (NODC Accession 0104350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104350 includes physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN232 in the Philippine Sea from 2009-04-02 to...

  7. Physical and underway data collected aboard the MELVILLE during cruise MV1301 in the North Pacific Ocean and Philippine Sea from 2013-01-16 to 2013-01-29 (NCEI Accession 0138037)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138037 includes physical and underway data collected aboard the MELVILLE during cruise MV1301 in the North Pacific Ocean and Philippine Sea from...

  8. Physical and underway data collected aboard the MELVILLE during cruise MV0910 in the North Pacific Ocean and Philippine Sea from 2009-10-31 to 2009-11-04 (NODC Accession 0089651)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089651 includes physical and underway data collected aboard the MELVILLE during cruise MV0910 in the North Pacific Ocean and Philippine Sea from...

  9. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1208 in the North Pacific Ocean, Philippine Sea and others from 2012-06-28 to 2012-07-17 (NCEI Accession 0138178)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138178 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1208 in the North Pacific Ocean, Philippine Sea and...

  10. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1006 in the Philippine Sea from 2010-05-08 to 2010-05-26 (NODC Accession 0089636)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089636 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1006 in the Philippine Sea from 2010-05-08 to...

  11. Physical and underway data collected aboard the ROGER REVELLE during cruise RR0914 in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2009-11-05 to 2009-11-14 (NODC Accession 0089672)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089672 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR0914 in the North Pacific Ocean, Philippine Sea and...

  12. Physical and underway data collected aboard the ROGER REVELLE during cruise RR0912 in the Philippine Sea from 2009-09-20 to 2009-10-08 (NODC Accession 0089630)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089630 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR0912 in the Philippine Sea from 2009-09-20 to...

  13. Physical and underway data collected aboard the ROGER REVELLE during cruise RR1516 in the Philippine Sea from 2015-11-13 to 2015-11-18 (NCEI Accession 0145841)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0145841 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR1516 in the Philippine Sea from 2015-11-13 to...

  14. Physical, chemical, and other data from CTD and XBT casts from the KOFU MARU and other platforms from the Philippine Sea and other locations from 24 November 1971 to 28 December 1989 (NODC Accession 9100090)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, and other data from CTD and XBT casts from the KOFU MARU and other platforms from the Philippine Sea and other locations. Data were collected by...

  15. Physical and underway data collected aboard the MELVILLE during cruise MV1302 in the North Pacific Ocean and Philippine Sea from 2013-02-01 to 2013-02-15 (NCEI Accession 0138038)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0138038 includes physical and underway data collected aboard the MELVILLE during cruise MV1302 in the North Pacific Ocean and Philippine Sea from...

  16. Physical and profile data collected aboard the ROGER REVELLE during cruise RR1413 in the North Pacific Ocean and Philippine Sea from 2014-11-28 to 2014-12-21 (NCEI Accession 0137259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0137259 includes physical and profile data collected aboard the ROGER REVELLE during cruise RR1413 in the North Pacific Ocean and Philippine Sea from...

  17. Crop Production of Northern Mindanao, Philippines: Its contribution to the Regional Economy and Food Security

    Directory of Open Access Journals (Sweden)

    Dejarme-Calalang, GM.

    2015-01-01

    Full Text Available This paper presents the contribution of primary agricultural crops produced in Northern Mindanao to its economy and food security of people with the situational analysis and insights of the authors. Rice as the staple food of most Filipinos is insufficient in quantity produced. Corn production is more than enough for the total regional demand. White corn is preferred as secondary staple food, however the corn industry emphasizes yellow corn production and the bulk of this goes to raw materials for livestock and poultry feeds. Coconut, sugar, pineapple and bananas significantly contribute to agricultural exports. Coconut is processed before exporting which can offer employment in the rural areas. Sugarcane, pineapple and bananas have created a change in the land use and hence compete with rice and corn. Northern Mindanao is one of the leading producers of tomatoes, carrots and potatoes, yet farmers have encountered deterring factors in attaining potential income from these products. Although Bukidnon province is the top agricultural producer in the region, poverty in the area remains high.

  18. THE NORTHERN SEA ROUTE: PRESENT CONDITION AND DEVELIPMENT PROSPECTS

    Directory of Open Access Journals (Sweden)

    R. A. Bryzgalov

    2011-01-01

    Full Text Available The Northern Sea Route (NSR represents a serious alternative to traditional so-called «southern» sea transportation routes passing through the Suez Canal. Data on the present and on most optimistic prospective scopes of transportation over NSR for different types of goods are presented in the article. Among main factors working for the optimistic perspective with respect of NSR there are measurements stipulated in several Russian governmental decrees, global rise in temperature and feasibility to develop natural resources abundantly available in the arctic areas of Russia. Still, there are negative factors such as the need of massive investment to transportation means and to local infrastructure, risks associated with the probability of particularly severe arctic natural phenomena and provision for safety in many aspects.

  19. Small scale features of sound velocity structure in the northern Arabian sea during February - May 1974

    Digital Repository Service at National Institute of Oceanography (India)

    Somayajulu, Y.K.; Rao, L.V.G.; Varadachari, V.V.R.

    Microstructure of sound velocity in the upper 500 m of the northern Arabian Sea based on STD (salinity-temperature-depth profiler) data is presented. Relatively warm and saline waters of the Persian Gulf intruding into the Arabian Sea...

  20. Atmospheric concentrations of persistent organic pollutants over the Pacific Ocean near southern Taiwan and the northern Philippines.

    Science.gov (United States)

    Chao, How-Ran; Lin, Ding-Yan; Chen, Kuang-Yu; Gou, Yan-Yu; Chiou, Tsyr-Huei; Lee, Wen-Jhy; Chen, Shui-Jen; Wang, Lin-Chi

    2014-09-01

    This study investigates the atmospheric occurrence of persistent organic pollutants (POPs) over the Pacific Ocean near southern Taiwan and the northern Philippines. We determined sixty-six compounds, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DLPCBs), polybrominated diphenyl ethers (PBDEs), as well as polychlorinated diphenyl ethers (PCDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polybrominated biphenyls (PBBs), in air samples simultaneously collected from the offshore oceanic atmosphere (n=6) and over a rural area (n=2). We calculated the atmospheric World Health Organization 2005 toxic equivalency levels (WHO2005-TEQ), for the total dioxin-like POPs, including PCDD/Fs, DLPCBs, and PBDD/Fs, being 0.00612 pg WHO2005-TEQ/m(3) and 0.0138 pg WHO2005-TEQ/m(3) over the ocean and land, respectively. We found unexpected lower averaged atmospheric PBDE concentrations in the rural area (15.9 pg/m(3)) than over the ocean (31.1 pg/m(3)) due to higher levels of the BDE209 congener, although the difference was not statistically significant. We have compared and reported our field results with previously published datasets over the global oceans, which suggest PCBs and PBDEs are the dominant chemical contaminants in the global oceanic atmosphere among these halogenated POPs (e.g. PCBs and Σdi-hepta PBDEs could be found in the range of 0.09-48.7 and 8.07-94.0 pg/m(3), respectively, including our dataset). However, there are still very few investigations on the global atmospheric levels of PBDD/Fs, PCDEs and PBBs and our data sums to these earlier studies. Finally, we point out that the halogenated POPs originated from Taiwan or the continental East Asia which could easily reach remote ocean sites via atmospheric transport.

  1. Views of the Sea Floor in Northern Monterey Bay, California

    Science.gov (United States)

    Storlazzi, Curt D.; Golden, Nadine E.; Finlayson, David P.

    2008-01-01

    A sonar survey that produced unprecedented high-resolution images of the sea floor in northern Monterey Bay was conducted in 2005 and 2006. The survey, performed over 14 days by the U.S. Geological Survey (USGS), consisted of 172 tracklines and over 300 million soundings and covered an area of 12.2 km2 (4.7 mi2). The goals of this survey were to collect high-resolution bathymetry (depth to the sea floor) and acoustic backscatter data (amount of sound energy bounced back from the sea floor, which provides information on sea-floor hardness and texture) from the inner continental shelf. These data will provide a baseline for future change analyses, geologic mapping, sediment- and contaminant-transport studies, benthic-habitat delineation, and numerical modeling efforts. The survey shows that the inner shelf in this area is extremely varied in nature, encompassing flat sandy areas, faults, boulder fields, and complex bedrock ridges that support rich marine ecosystems. Furthermore, many of these complex bedrock ridges form the ?reefs? that result in a number of California?s classic surf breaks.

  2. Additional Arctic observations improve weather and sea-ice forecasts for the Northern Sea Route.

    Science.gov (United States)

    Inoue, Jun; Yamazaki, Akira; Ono, Jun; Dethloff, Klaus; Maturilli, Marion; Neuber, Roland; Edwards, Patti; Yamaguchi, Hajime

    2015-01-01

    During ice-free periods, the Northern Sea Route (NSR) could be an attractive shipping route. The decline in Arctic sea-ice extent, however, could be associated with an increase in the frequency of the causes of severe weather phenomena, and high wind-driven waves and the advection of sea ice could make ship navigation along the NSR difficult. Accurate forecasts of weather and sea ice are desirable for safe navigation, but large uncertainties exist in current forecasts, partly owing to the sparse observational network over the Arctic Ocean. Here, we show that the incorporation of additional Arctic observations improves the initial analysis and enhances the skill of weather and sea-ice forecasts, the application of which has socioeconomic benefits. Comparison of 63-member ensemble atmospheric forecasts, using different initial data sets, revealed that additional Arctic radiosonde observations were useful for predicting a persistent strong wind event. The sea-ice forecast, initialised by the wind fields that included the effects of the observations, skilfully predicted rapid wind-driven sea-ice advection along the NSR.

  3. The tug-of-war between the West Philippine Sea and South China Sea Tropical Waters and Intermediate Waters in the Okinawa Trough

    Science.gov (United States)

    Chen, Chen-Tung Arthur; Yeh, Ya-Ting; Yanagi, Tetsuo; Bai, Yan; He, Xianqiang; Huang, Ting-Hsuan

    2016-03-01

    Kuroshio subsurface waters are the major source of nutrients to the East China Sea continental shelf, a major fishing ground. These subsurface waters are heavily affected by the South China Sea (SCS) Tropical and Intermediate Waters which contain more nutrients than the tropical (Smax) and intermediate (Smin) waters from the West Philippine Sea (WPS). A front was found to separate these waters from the SCS and WPS. The reported front in the Okinawa Trough, however, was identified based only on one-time data from a single cross section. Here historical hydrographic data between March 1950 and December 2011 are analyzed. A vertical front tilted toward the west is found in all seasons in all years in the Okinawa Trough. In winter, the presence of the SCS Tropical Water is the most prominent. It is the weakest in autumn. As for intermediate waters (Smin), the WPS and SCS Intermediate Waters show much weaker seasonality compared with tropical waters although in summer, the WPS Intermediate Water contribution is slightly larger than during other times.

  4. Late Holocene hydrographic settings of the northern Red Sea

    Directory of Open Access Journals (Sweden)

    Amani Badawi

    2016-03-01

    Full Text Available Temporal variability of the paleo-oceanographic setting of the northern Red Sea during the last 6 Ky was deduced from high-resolution faunal results and stable isotope records of planktonic foraminifera in three short cores sediment obtained by the German R/V Meteor vessel. In general, the investigated time interval is fundamentally comparable to the present day composition and distribution of planktonic foraminifera. However, interrupted short enhanced arid phase spanning the last 4–2 Ky appears to have existed in the northern Red Sea, and resulted in elevation of salinity and somehow productivity, as hypersaline, dense surface water favored vertical mixing of the water column resulting in an increase in productivity. This paleoclimatic reconstruction is revealed from the distinct gradient in the composition and distribution of planktonic foraminifera, as well as the significant distribution trend of Globigerinoides ruber versus Globigerinoides sacculifer correlated with the stable isotope records. Starting from the last 2 Ky to the present time, less strength arid conditions relative to the previous period prevailed, reflected from a gradual decrease in surface water salinity and productivity assuming that the present water conditions and consequently current climatic conditions began to develop from that time with minor fluctuations reaching the recent conditions.

  5. Crustal underthrusting in the Crimea - Northern Black Sea area

    Science.gov (United States)

    Yegorova, Tamara; Gobarenko, Valentina; Murovskaya, Anna; Sheremet, Yevgeniya

    2016-04-01

    The southern Crimean Mountains and the Greater Caucasus form a fold and thrust belt located on the northern margin of the Black Sea, south of Precambrian East European Craton. It is limited to the south by the Main Caucasus Thrust that runs along the whole of the northern margin of the Black Sea and is related to a zone of present day seismicity along the southern Crimea-Caucasus coast of the Sea (Crimean Seismogenic Zone). Strong seismic activity in the region indicates active on-going tectonic processes caused by collision of Eurasian and Arabian plates. In the vicinity of the seismogenic zone there is a transition from thick continental crust on the north to thin suboceanic one on the south in the sea. However, type and structural relations between them are known poorly. To understand better geodynamic processes, there were collected data on the earthquakes that were analyzed together with focal mechanisms of strong earthquakes, new results of geological structural analysis and paleostress reconstructions by kinematic method. These allowed drawing the following conclusions. Seismic activity in the study region, evidenced of active tectonic processes under compression and transpression at the transition from the southern margin of the East European Craton (Scythian Platform) to the Black Sea, is confirmed by predominance of reverse mechanisms among 31 focal mechanisms. In the seismogenic zone, much of which is located along the continental slope, there are three subzones (from east to west): 1) Kerch-Taman one dipping northwards at angle 30 degrees to the depth of 90 km; 2) South-Coast subzone gently dipping to the southeast at angle of 18 degrees with foci depth range 10-45 km, and 3) orthogonal to the latter and confining it from the west the Sevastopol one, characterized by scattered seismicity. The earthquake foci are located in the gradient zone that separates intense Crimea gravity high and positive anomaly of Northern Caucasus from negative gravity field

  6. Bartonella spp. exposure in northern and southern sea otters in Alaska and California.

    Science.gov (United States)

    Carrasco, Sebastian E; Chomel, Bruno B; Gill, Verena A; Doroff, Angela M; Miller, Melissa A; Burek-Huntington, Kathleen A; Kasten, Rickie W; Byrne, Barbara A; Goldstein, Tracey; Mazet, Jonna A K

    2014-12-01

    Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To evaluate the extent of exposure to Bartonella spp. in sea otters, sera collected from necropsied and live-captured northern sea otters, as well as necropsied southern sea otters (Enhydra lutris nereis) unaffected by the UME, were analyzed using an immunofluorescent antibody assay. Antibodies against Bartonella spp. were detected in sera from 50% of necropsied and 34% of presumed healthy, live-captured northern sea otters and in 16% of necropsied southern sea otters. The majority of sea otters with reactive sera were seropositive for B. washoensis, with antibody titers ranging from 1:64 to 1:256. Bartonella spp. antibodies were especially common in adult northern sea otters, both free-living (49%) and necropsied (62%). Adult stranded northern sea otters that died from infectious causes, such as opportunistic bacterial infections, were 27 times more likely to be Bartonella seropositive than adult stranded northern sea otters that died from noninfectious causes (pBartonella spp. antibodies were detected in necropsied northern sea otters from southcentral (44%) and southwestern (86%) stocks of Alaska, as well as in necropsied southern sea otters (16%) in southcentral California, we concluded that Bartonella spp. exposure is widely distributed among sea otter populations in the Eastern Pacific, providing context for investigating future disease outbreaks and monitoring of Bartonella infections for sea otter management and conservation.

  7. Holocene coastal sea surface temperature changes in the northern South China Sea

    Science.gov (United States)

    Zhu, K.; Kong, D.; Wei, G.; Liu, Z.

    2016-12-01

    Holocene sea surface temperature (SST) changes in the northern South China Sea (SCS) coastal region are affected by complex factors. Previous studies have identified a long-term cooling trend, attributed to coastal mixing and intensified East Asian Winter Monsoon (EAWM), yet spatial patterns of coastal cooling along the southern China are still not well established. Here we reconstructed a Holocene Sea Surface Temperature (SST) record, derived from long-chain alkenone unsaturation index - UK'37, in the northern SCS. Our result reveals that a gentle cooling trend dominates the mid-late Holocene. The gradual warming trend occurring during the early Holocene might have resulted from the rising sea level or the rebound of "8.2 ka cold event". Besides, the C37-content also shows an extremely-low level before 8 ka. Later, both alkenone-derived SST and C37-content reach their highest levels during approximately 7-4.5 ka, corresponding to the Holocene Climate Optimum (HCO). Consistent with previous studies, the long-term cooling trend identified in coastal regions, but not offshore ones, presumably indicates intensified EAWM toward present. Further, during the late Holocene, coastal SST changes in the northern SCS show heterogeneous responses to global climatic conditions. In the Mirs Bay, SST was warmer during the Little Ice Age (LIA) than the Medieval Warm Period (WMP) and the current warm period, interpreted as reflecting intensified coastal mixing, due to strengthened East Asian Summer Monsoon (EASM) during warmer periods. However, SST records at other coastal sites, as well as offshore regions, show fluctuations consistent with global/northern hemisphere temperature changes, suggesting that these regions are less influenced by the EASM-induced coastal mixing, probably with the aid of Pearl River freshwater input.

  8. Clusters of interannual sea ice variability in the northern hemisphere

    Science.gov (United States)

    Fučkar, Neven S.; Guemas, Virginie; Johnson, Nathaniel C.; Massonnet, François; Doblas-Reyes, Francisco J.

    2016-09-01

    We determine robust modes of the northern hemisphere (NH) sea ice variability on interannual timescales disentangled from the long-term climate change. This study focuses on sea ice thickness (SIT), reconstructed with an ocean-sea-ice general circulation model, because SIT has a potential to contain most of the interannual memory and predictability of the NH sea ice system. We use the K-means cluster analysis—one of clustering methods that partition data into groups or clusters based on their distances in the physical space without the typical constraints of other unsupervised learning statistical methods such as the widely-used principal component analysis. To adequately filter out climate change signal in the Arctic from 1958 to 2013 we have to approximate it with a 2nd degree polynomial. Using 2nd degree residuals of SIT leads to robust K-means cluster patterns, i.e. invariant to further increase of the polynomial degree. A set of clustering validity indices yields K = 3 as the optimal number of SIT clusters for all considered months and seasons with strong similarities in their cluster patterns. The associated time series of cluster occurrences exhibit predominant interannual persistence with mean timescale of about 2 years. Compositing analysis of the NH surface climate conditions associated with each cluster indicates that wind forcing seem to be the key factor driving the formation of interannual SIT cluster patterns during the winter. Climate memory in SIT with such interannual persistence could lead to increased predictability of the Artic sea ice cover beyond seasonal timescales.

  9. Prediction of sea ice thickness cluster in the Northern Hemisphere

    Science.gov (United States)

    Fuckar, Neven-Stjepan; Guemas, Virginie; Johnson, Nathaniel; Doblas-Reyes, Francisco

    2016-04-01

    Sea ice thickness (SIT) has a potential to contain substantial climate memory and predictability in the northern hemisphere (NH) sea ice system. We use 5-member NH SIT, reconstructed with an ocean-sea-ice general circulation model (NEMOv3.3 with LIM2) with a simple data assimilation routine, to determine NH SIT modes of variability disentangled from the long-term climate change. Specifically, we apply the K-means cluster analysis - one of nonhierarchical clustering methods that partition data into modes or clusters based on their distances in the physical - to determine optimal number of NH SIT clusters (K=3) and their historical variability. To examine prediction skill of NH SIT clusters in EC-Earth2.3, a state-of-the-art coupled climate forecast system, we use 5-member ocean and sea ice initial conditions (IC) from the same ocean-sea-ice historical reconstruction and atmospheric IC from ERA-Interim reanalysis. We focus on May 1st and Nov 1st start dates from 1979 to 2010. Common skill metrics of probability forecast, such as rank probability skill core and ROC (relative operating characteristics - hit rate versus false alarm rate) and reliability diagrams show that our dynamical model predominately perform better than the 1st order Marko chain forecast (that beats climatological forecast) over the first forecast year. On average May 1st start dates initially have lower skill than Nov 1st start dates, but their skill is degraded at slower rate than skill of forecast started on Nov 1st.

  10. Imprints of Late Mesozoic tectono-magmatic events on Palawan Continental Block in northern Palawan, Philippines

    Science.gov (United States)

    Padrones, Jenielyn T.; Tani, Kenichiro; Tsutsumi, Yukiyasu; Imai, Akira

    2017-07-01

    A recent investigation in Palawan Island led to the recognition of the Daroctan Granite, a pluton that intruded the Mesozoic mélange in the northernmost part. The occurrence and age of the magmatism is presented in this study as well as the maximum age of deposition for some Late Mesozoic lithostratigraphic units. Geochronological studies on zircon and monazite was carried out to unravel the Late Mesozoic tectonic evolution of this area. Monazite U-Th-total Pb dating was used to determine the age of the Daroctan Granite, which yielded a Late Cretaceous age similar to some of the Mesozoic granites surrounding the South China Sea. Zircon U-Pb and monazite U-Th-total Pb dating were also used to determine the maximum age of deposition of the sedimentary units belonging to the Guinlo Formation and Tumarbong Semi-schist. The results show a Jurassic to Early Cretaceous age range with a Late Cretaceous maximum age of deposition for the meta-sedimentary units. This sliver of the Palawan Continental Block, which is composed of accreted units, might have been located at the margin of the continent-ocean collision during the Mesozoic wherein detrital minerals with mostly Late Cretaceous ages were deposited. It was later intruded by the Daroctan Granite and eventually broke off from the southeastern Eurasian margin. These findings provide additional constraints on the tectonic evolution of the Palawan Continental Block.

  11. Aerosol meteorology and Philippine receptor observations of Maritime Continent aerosol emissions for the 2012 7SEAS southwest monsoon intensive study

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Jeffrey S; Lagrosas, Nofel D.; Jonsson, Haflidi H.; Reid, Elizabeth A.; Atwood, Samuel A.; Boyd, Thomas J.; Ghate, Virendra P.; Lynch, Peng; Posselt, Derek J; Simpas, James B; Uy, Sherdon N; Zaiger, Kimo; Blake, Donald R; Bucholtz, Anthony; Campbell, James A.; Chew, Boon Ning; Cliff, Steven; Holben, Brent N; Holz, Robert E.; Hyer, Edward J.; Ogren, John A.; Kriedendweiss, Sonia; Kuciaskas, Arunas; Lolli, Simone; Oo, Min; Perry, Kevin; Salinas, Santo V.; Sessions, Walter; Smirnov, Alexander; Walker, Annette; Wang, Qing; Yu, Liya; Zhang, Jianglong; Zhao, Yongjing

    2016-11-15

    Since 2007 the 7 Southeast Asian Studies (7SEAS) program has been collecting in situ data and analyzing satellite and model fields for aerosol phenomenon throughout Southeast Asia. The most significant intensive operations period associated with the boreal summertime southwest monsoon biomass burning season across the Maritime Continent occurred in August-September 2012, with enhanced deployment of Aerosol Robotic Network (AERONET) sun photometers, multiple lidars, and a Singapore supersite. These deployments were largely within or near pollution and biomass burning aerosol source regions. Simultaneously, a ship was dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for September 2012 to observe transported smoke and pollution as it entered the southwest monsoon monsoonal trough. In this paper we describe the nature of the overall 2012 southwest monsoon biomass burning season, but focus on the findings of the research cruise and the aerosol meteorology that explains the measured variability in marine boundary layer aerosol characteristics in this convectively active region. This 2012 cruise was a follow-on to a 2 week cruise in 2011, and was in part consistent with the findings of that cruise and previous conceptual models of how smoke emission and transport relates to monsoonal flows, the propagation of the Madden Julian Oscillation (MJO), tropical cyclones, and covariance between smoke transport events and the atmosphere’s thermodynamic structure. High-resolution observations in the 2011 cruise also highlighted the importance of squall lines and cold pools as they propagate across the South China Sea scavenging aerosol particles in their path. For 2012, the research cruise experienced some different environments. While ENSO was on a borderline positive phase and enhanced emissions were observed over climatologically average years, the MJO was weak and stalled over the Maritime Continent during the cruise. The monsoonal flow direction was

  12. Sea level, paleogeography, and archeology on California's Northern Channel Islands

    Science.gov (United States)

    Reeder-Myers, Leslie; Erlandson, Jon M.; Muhs, Daniel R.; Rick, Torben C.

    2015-01-01

    Sea-level rise during the late Pleistocene and early Holocene inundated nearshore areas in many parts of the world, producing drastic changes in local ecosystems and obscuring significant portions of the archeological record. Although global forces are at play, the effects of sea-level rise are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Interpretations of coastal paleoecology and archeology require reliable estimates of ancient shorelines that account for GIA effects. Here we build on previous models for California's Northern Channel Islands, producing more accurate late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability. This region has contributed significantly to our understanding of early New World coastal foragers. Sea level that was about 80–85 m lower than present at the time of the first known human occupation brought about a landscape and ecology substantially different than today. During the late Pleistocene, large tracts of coastal lowlands were exposed, while a colder, wetter climate and fluctuating marine conditions interacted with rapidly evolving littoral environments. At the close of the Pleistocene and start of the Holocene, people in coastal California faced shrinking land, intertidal, and subtidal zones, with important implications for resource availability and distribution.

  13. Unusual growth in intense typhoon occurrences over the Philippine Sea in September after the mid-2000s

    Science.gov (United States)

    He, Haozhe; Yang, Jing; Wu, Liguang; Gong, Daoyi; Wang, Bin; Gao, Miaoni

    2017-03-01

    During the global warming hiatus period (1998-present), a pronounced increase in the number of intense typhoon occurrences was identified over the Philippine Sea (PS: 5°-25°N, 125°-140°E) in September after the mid-2000s. Comparing two periods before and after the mid-2000s indicates that intense typhoons rarely occurred over the PS in September before the mid-2000s, with a frequency of fewer than 0.4 per year, but reached up to nearly 1.5 per year after the mid-2000s. The abrupt increase in intense typhoon occurrences over the PS was primarily attributed to increased tropical cyclone (TC) genesis and favorable large-scale conditions for TC intensification. The increase in TC genesis number over the PS was caused by contributory dynamical conditions, including positive low-level relative vorticity anomalies and anomalous ascents, which corresponded to a southwestward shift and strengthening of the monsoon trough. In addition, among the favorable large-scale conditions, the increased relative humidity that resulted from intensified moisture flux convergence exerted essential effect on the TC intensification. These changes in atmospheric environmental conditions favoring intense typhoon occurrences over the PS were primarily associated with the change in the tropical Indo-Pacific sea surface temperature (SST) around the mid-2000s. Besides that, the positive feedback TCs exerted on the circulation was also conducive to the unusual growth in intense typhoon occurrences over the PS. And note that the role of SST anomalies in the air-sea interaction is the key to interpret why the unique phenomenon only occurred in September.

  14. Wind atlas of the Northern European Seas based on Envisat ASAR, QuikSCAT and ASCAT

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Mouche, Alexis; Badger, Merete

    In the EU project NORSEWInD (Northern Seas Wind Index database, www.norsewind.eu) which lasted from 2008 to 2012 there was a goal of contributing a satellite-based wind atlas for the Northern European Seas. The effort included collection of more than 9000 Envisat ASAR WSM wide swath mode scenes...

  15. Holocene hydrological and sea surface temperature changes in the northern coast of the South China Sea

    Science.gov (United States)

    Wu, Mong-Sin; Zong, Yongqiang; Mok, Ka-Man; Cheung, Ka-Ming; Xiong, Haixian; Huang, Guangqing

    2017-03-01

    In order to reconstruct the Holocene environmental history of a coastal site in the northern South China Sea, this study analysed the organic carbon isotope ratios (δ13Corg) and alkenone unsaturation ratios (UK‧37) from a 36.5 m-long sediment core drilled at seabed in the mouth region of the Pearl River estuary and generated a coupled hydrological and temperature record. This record reveals changes of monsoon-induced sediment discharge and sea surface temperature of the Holocene in four stages. In Stage I, the site was under fluvial conditions prior to postglacial marine transgression. Stage II saw an increase of sea surface temperature from c. 23.0 °C to 27.0 °C, associated with a strengthened summer monsoon from c. 10,350 to 8900 cal. years BP. This was also a period of rapid sea-level rise and marine transgression, during which the sea inundated the palaeo-incised channel, i.e. the lower part of the T-shape accommodation space created by the rising sea. In these 1500 years, fluvial discharge was strong and concentrated within the channel, and the high sedimentation rate (11.8 mm/year) was very close to the rate of sea-level rise. In the subsequent 2000 years (Stage III) sea level continued to rise and the sea flooded the broad seabed above the palaeo-incised channel, resulted in fluvial discharge spreading thinly across the wide accommodation space and a much reduced sedimentation rate (1.8 mm/year). Sea surface temperature in this stage reached 27.3 °C initially, but dropped sharply to 26.1 °C towards c. 8200 cal. years BP. The final stage covers the last 7000 years, and the site was under a stable sea level. Sedimentation in this stage varied a little, but averaged at 1.8 mm/year. Whilst fluvial discharge and sea surface temperature didn't change much, two short periods of hydrological and temperature change were observed, which are related to the climatic cooling events of c. 4200 cal. years ago and the Little Ice Age.

  16. The Pacific and Philippine Sea slabs in contact beneath Tokyo, central Japan: their roles in defining hazardous interaction earthquakes and in limiting the southern extent of Tohoku-oki aftershocks

    Science.gov (United States)

    Okaya, D. A.; Sato, H.; Lavier, L. L.; Tan, E.; Wu, F. T.; Hirata, N.

    2011-12-01

    The M9 Tohoku-oki earthquake produced over 11,000 >M3 aftershocks within the first four months after its 2011 March 11 occurrence date. The majority of these aftershocks define the earthquake source region between the subducting Pacific plate (PAC) and its overlying Eurasian plate (EUR) along the Japan Trench. While this portion of the trench boundary extends southward to the Boso triple junction (latitude ~34.3 oN), the Tohoku-oki aftershocks predominantly terminate at ~35.7 oN. Between these two latitudes there is a marked dropoff in aftershocks, most noticably offshore of Boso Peninsula, eastern Kanto, which we refer to as the off-Boso aftershock gap. Inside this gap, aftershocks that have occurred form two narrow-width streaks that radiate from the triple junction and extend into central Kanto. There is a correlation between the location of the off-Boso aftershock gap and the northern extent of the Philippine Sea plate (PHS). The PHS is sandwiched between the PAC-EUR plates beneath Kanto. While the majority of Tohoku-oki aftershocks occur within the one-slab PAC-EUR system to the north, the off-Boso gap is updip of where the PHS slab is resident inside the PAC-EUR mantle wedge. Furthermore, the northern of the two aftershock streaks spatially correlates with the downdip extent of the PHS with many located at the PHS-PAC contact based on published tomographic/seismicity studies. The presence of PHS changes the conditions of PAC-EUR slip. Preliminary finite-source studies from web sources (e.g., Univ Tokyo, Harvard) show that Tohoku-oki rupture terminated just north of the off-Boso gap. Apparently, the presence of the Philippine Sea plate may have been a contributing factor to inhibiting this rupture from propagating further southward. The megathrust source faults beneath Kanto are associated with the tops of Philippine Sea and Pacific plates. These shallow source faults have been the focus of much recent geological and geophysical study including seismicity and

  17. Relative paleointensity of the geomagnetic field during the past 200 ka from the West Philippine Sea and its chronological significance

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Our rock magnetic analysis of core Ph05 from the West Philippine Sea demonstrates that the core preserves a strong, stable remanent magnetization and meets the magnetic mineral criteria for relative paleointensity (RPI) analyses. The magnetic minerals in the sequence are dominated by pseudosingle-domain magnetite, and the concentration of magnetic minerals is at the same scale. Both the conventional normalizing method and the pseudo-Thellier method were used in conjunction with the examination of the rock magnetic properties and natural remanent magnetization. Susceptibility (χ), anhysteretic remnant magnetization (ARM) and saturation isothermal remnant magnetization (SIRM) were used as the natural remanent magnetization normalizer. However, coherence analysis indicated that only ARM is more suitable for paleointensity reconstruction. The age model of core is established based on oxygen isotope data and AMS14C data, which is consistent with the age model estimated from RPI records. The relative paleointensity data provide a continuous record of the intensity variation during the last 200 ka, which correlates well with the global references RPI stacks. Several prominent low paleointensity values are identified and are correlated to the main RPI minima in the SINT-200 record, suggesting that the sediments have recorded the real changes of geomagnetic field.

  18. Relative paleointensity of the geomagnetic field during the past 200 ka from the West Philippine Sea and its chronological significance

    Institute of Scientific and Technical Information of China (English)

    MENG QingYong; LI AnChun; LI TieGang; JIANG FuOing; ZHOU XiaoJing

    2009-01-01

    Our rock magnetic analysis of core Ph05 from the West Philippine Sea demonstrates that the core preserves a strong, stable remanent magnetization and meets the magnetic mineral criteria for relative paleointensity (RPI) analyses. The magnetic minerals in the sequence are dominated by pseudosingle-domain magnetite, and the concentration of magnetic minerals is at the same scale. Both the conventional normalizing method and the pseudo.Thellier method were used in conjunction with the examination of the rock magnetic properties and natural remanent magnetization. Susceptibility (X), anhysteretic remnant magnetization (ARM) and saturation isothermal remnant magnetization (SIRM) were used as the natural remanent magnetization normalizer. However, coherence analysis indicated that only ARM is more suitable for paleointensity reconstruction. The age model of core is established based on oxygen isotope data and AMS14C data, which is consistent with the age model estimated from RPI records. The relative paleointensity data provide a continuous record of the intensity variation during the last 200 ka, which correlates well with the global references RPI stacks. Several prominent low paleointensity values are identified and are correlated to the main RPI minima in the SINT-200 record, suggesting that the sediments have recorded the real changes of geomagnetic field.

  19. Economic Possibilities of Shipping though Northern Sea Route1

    Directory of Open Access Journals (Sweden)

    Sung-Woo Lee

    2014-12-01

    Full Text Available Global warming and climate change haves brought a new issue in the Arctic sea. Therefore, we can now explore new shipping routes through the Arctic Ocean instead of the existing commercial route. In particular, the Northern Sea Route (NSR is one of the feasible shipping routes and, has provided tremendous shipping benefits. If the NSR becomes commercialized, we will be able to save about 5,000 nautical miles in distance and sailing time. In this study, we will emphasize some of the important results on the possibility of commercializing the shipping route in the Arctic. The NSR may bring positive economic effects in terms of shipping distance and time. For example, when utilizing the NSR, the maximum cargo traffic between Asia and Europe is expected to be around 46 million TEU. However, we also need to consider an expensive passage fee that is currently imposed by Russia. In conclusion, we maintain our efforts to protect the environment in the Arctic, in terms of logistics, and we need to explore every possible avenue to bring possible economic benefits to the North Pacific countries.

  20. Sea level rise projections for Northern Europe under RCP8.5

    NARCIS (Netherlands)

    Grinsted, A.; Jevrejeva, S.; Riva, R.E.M.; Dahl-Jensen, D.

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the

  1. Sea level rise projections for Northern Europe under RCP8.5

    NARCIS (Netherlands)

    Grinsted, A.; Jevrejeva, S.; Riva, R.E.M.; Dahl-Jensen, D.

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the

  2. Philippine Sea Plate inception, evolution, and consumption with special emphasis on the early stages of Izu-Bonin-Mariana subduction

    Science.gov (United States)

    Lallemand, Serge

    2016-12-01

    We compiled the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent. We also analyzed the various explanatory models in light of this updated dataset. The following main conclusions are discussed in this study. (1) The Izanagi slab detachment beneath the East Asia margin around 60-55 Ma likely triggered the Oki-Daito plume occurrence, Mesozoic proto-PSP splitting, shortening and then failure across the paleo-transform boundary between the proto-PSP and the Pacific Plate, Izu-Bonin-Mariana subduction initiation and ultimately PSP inception. (2) The initial splitting phase of the composite proto-PSP under the plume influence at ˜54-48 Ma led to the formation of the long-lived West Philippine Basin and short-lived oceanic basins, part of whose crust has been ambiguously called "fore-arc basalts" (FABs). (3) Shortening across the paleo-transform boundary evolved into thrusting within the Pacific Plate at ˜52-50 Ma, allowing it to subduct beneath the newly formed PSP, which was composed of an alternance of thick Mesozoic terranes and thin oceanic lithosphere. (4) The first magmas rising from the shallow mantle corner, after being hydrated by the subducting Pacific crust beneath the young oceanic crust near the upper plate spreading centers at ˜49-48 Ma were boninites. Both the so-called FABs and the boninites formed at a significant distance from the incipient trench, not in a fore-arc position as previously claimed. The magmas erupted for 15 m.y. in some places, probably near the intersections between back-arc spreading centers and the arc. (5) As the Pacific crust reached greater depths and the oceanic basins cooled and thickened at ˜44-45 Ma, the composition of the lavas evolved into high-Mg andesites and then arc tholeiites and calc-alkaline andesites. (6) Tectonic erosion processes removed about 150-200 km of frontal margin during the Neogene, consuming most or all of the Pacific ophiolite

  3. Late summer zoogeography of the northern Bering and Chukchi seas

    Science.gov (United States)

    Sigler, Michael F.; Mueter, Franz J.; Bluhm, Bodil A.; Busby, Morgan S.; Cokelet, Edward D.; Danielson, Seth L.; Robertis, Alex De; Eisner, Lisa B.; Farley, Edward V.; Iken, Katrin; Kuletz, Kathy J.; Lauth, Robert R.; Logerwell, Elizabeth A.; Pinchuk, Alexei I.

    2017-01-01

    assemblages. The gradients in assemblage composition were gradual for epibenthic taxa, abrupt for zooplankton taxa, and intermediate for pelagic fish/jellyfish and seabird taxa, implying that zooplankton assemblage structure is most strongly tied to water mass, epibenthic least, with the other two taxa intermediates. Three communities (i.e., cross-assemblage groupings) emerged based on maps of ordination axes and core use areas by taxa; one associated with Alaska Coastal Water (warmer, fresher, nutrient depauperate), second associated with Chirikov Basin and the southern Chukchi Sea (colder, saltier, nutrient rich), and third associated with the northern Chukchi shelf (colder and saltier but not as nutrient rich). Gradients in species composition occurred both within and between these communities. The Chirikov Basin/southern Chukchi Sea community was characterized by distinct zooplankton and seabird taxa, but was not strongly associated with distinct pelagic or epibenthic fish and invertebrate taxa. Although comprehensive data were only available for a single year and annual variation may affect the generality of our results, our comprehensive ecosystem survey approach yielded new insights into the ecological relationships (specifically, gradients in assemblage composition and identification of communities) of this Arctic region.

  4. Deep Water Ocean Acoustics (DWOA): The Philippine Sea, OBSANP, and THAAW Experiments

    Science.gov (United States)

    2015-09-30

    experiments, (2) 2013 Ocean Bottom Seismometer Augmentation in the North Pacific (OBSANP) experiment, and (3) 2013 THin-ice Arctic Acoustic Window (THAAW...scattering by internal waves and spice (density- compensated temperature and salinity variations), (iv) characterizing the depth dependence and temporal...geometrically with depth. Temperature and salinity were measured by thermistors in the hydrophone modules and ten Sea-Bird MicroCATs (J. Colosi, NPS

  5. Seismotectonics at the junction of the Philippine Sea plate and the Eurasian plate, in light of the 1990 Hualien earthquake and the near-field waveform inversion

    Science.gov (United States)

    Cheng, Hou-Sheng; Mozziconacci, Laetitia; Chang, Emmy T. Y.; Huang, Bor-Shouh

    2016-04-01

    In eastern Taiwan, the Longitudinal Valley (LV) is the suture zone separating the Eurasian plate (EUP) to the West from the Philippine Sea plate (PSP) to the East. The northern tip of the LV (near Hualien city) is the junction point where the collision evolve northward to a subduction of the PSP under the EUP. As a result, a high seismic activity is observed. Based on the CWB (Central Weather Bureau, Taiwan) earthquake catalog, four distinct seismic clusters can be observed in this area since 1990. We restrict our effort to the cluster caused by a doublet events of 1990 with two moderate-large earthquakes. The first shock of these doublet occurred on 13rd December with ML 6.5. Seventeen hours later and 15 km to the southeast occurred the second shock of ML 6.7. A campaign seismic network of 15 short-period stations - the Hualien Temporary Seismic Network (HTSN) was deployed during 2 months to detect the aftershocks of the doublet. By applying the near-field waveform inversion to the HTSN records, we can retrieve the focal mechanism solutions (FMS) from 50 aftershocks of local magnitude ranging from 2.5 to 5.0. A modified version of the program "FMNEAR" is adopted in this study, which has been proven to be efficient to retrieve FMS for small-to-moderate earthquakes with a limited number of stations. In practice, the near-field waveforms, were processed by band-pass filter between 0.52 and 1.2 Hz. Synthetic waveforms are built from the discrete wave number method of Bouchon (1981). The inversion is done by grid searches on the FMS parameters while the rake is inverted, the best result gives the lowest waveform misfit. The waveform adjustment are improved by depth optimization and a specific 1D velocity model for each station. Focal depths of events are in average 10km deeper than the depth determined by the island-wide seismic stations that suffered from the lack of stations to the east due to the ocean. The FMS of the 50 aftershocks can be classified into three

  6. The circulation in the southern Huanghai Sea and northern East China Sea in June 1999

    Institute of Scientific and Technical Information of China (English)

    Yaochu Yuan; Yonggang Liu; Mingyu Zhou; Arata Kaneko; Zhou Yuan; Noriaki Gohda

    2003-01-01

    On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method.The Kuroshio flows northeastward through eastern part of the investigated region and has the main coreat Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy be-tween these two northward flows, and a weak cyclonic eddy at the western part of Section PN. Theabove current structure is one type of the current structures at Section PN in ECS. The net northwardvolume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB)through Section PN is about 26.2× 106 m3/s in June 1999. The VT of the inshore branch of TaiwanWarm CArrent (TWCIB) through the investigated region is about 0.4 × 106 m3/s. The Taiwan WarmCurrent (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea CoastalCurrent (HSCC) flows southeastward and enters into the northwestern part of investigated region, andflows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan WarmCurrent and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea CoastalCurrent flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and coldwater is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 atthe northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).

  7. Thermocline bulk shear analysis in the northern North Sea

    Science.gov (United States)

    Chen, Shengli; Polton, Jeff A.; Hu, Jianyu; Xing, Jiuxing

    2016-04-01

    Thermocline bulk shear is investigated in the northern North Sea using historical observations. The conventional bulk shear is modified to define a thermocline bulk shear (TBS), in order to better represent the shear across the thermocline. The TBS computed by observed currents is decomposed into components at different frequency bands. The near-inertial TBS is the largest component. Its dominance is significant during the period of high wind. It is formed by the wind-driven near-inertial current which has a distinct phase shift (˜180°) across the thermocline. A linear model is presented, which well simulates the observed near-inertial TBS, especially during the period of relatively strong wind. The semidiurnal TBS makes a secondary contribution to the total TBS. It is only slightly smaller than the near-inertial TBS when the wind is relatively weak. The large values of semidiurnal TBS are associated with semidiurnal currents which have a phase shift (˜30-40°) or a magnitude difference (˜5 cm/s) across the thermocline. The low-frequency (<0.7 cpd) TBS also makes an episodic contribution to the total. Its variation coincides with the Ekman transport during the period of relatively strong wind. The low-frequency TBS is mainly formed by an Ekman-like clockwise spiraling of velocity with depth or a distinct magnitude difference in velocities between upper and lower layers.

  8. SEASONAL REVERSE OF SEA SURFACE SLOPE IN THE NORTHERN YELLOW SEA AND ITS DYNAMIC RELATION WITH MONSOON EFFECTS

    Institute of Scientific and Technical Information of China (English)

    PU Shu-zhen; CHENG Jun; ZHANG Yi-jun; SHI Qiang

    2004-01-01

    Based on the monthly average sea level data from the tide gauge measurement(1999-2001),the seasonal variability of the sea level in the Northern and Middle Yellow Sea is studied to reveal that the sea surface height at all the tide gauges becomes higher in summer than that in winter.In addition,the sea surface height of the Northern Yellow Sea is higher than the one of the Middle Yellow Sea with a slope downward from the north to the south in summer,while it is lower with a reversed slope in winter.The seasonal reverse of the sea surface slope can be attributed to the monsoon effects i.e.the annual reverse of the monsoon direction and the annual variation of the monsoon rainfall.A set of equations are established in light of the dynamic principles to expound how the monsoon forcing and the sea surface slope generate a summer outflow and a winter inflow in the Yellow Sea.

  9. State of oil pollution in the northern Arabian Sea after the 1991 Gulf oil spill

    Digital Repository Service at National Institute of Oceanography (India)

    Sengupta, R.; Fondekar, S.P.; Alagarsamy, R.

    Following the enormous oil spills resulting from the 1990-91 military conflict in the Gulf, fears were expressed concerning dissipation of oil from the Gulf into the Arabian Sea and Indian Ocean. To investigate contamination of the northern Arabian...

  10. MOLECULAR CHARACTERIZATION OF ANISAKID NEMATODES IN FISHES OF NORTHERN SARDINIAN SEA

    Directory of Open Access Journals (Sweden)

    T. Tedde

    2012-08-01

    Full Text Available The authors report results of analysis carried out during 2008-2010 for identification and molecular characterization of larval Anisakis nematodes isolated from fishes of the northern Sardinian sea.

  11. Early tertiary seafloor spreading magnetic anomalies and paleo-propagators in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.; Bhattacharya, G.C.; Murty, G.P.S.; Srinivas, K.; Ramprasad, T.; Rao, D.G.

    Study of closely spaced new marine magnetic profiles, in conjunction with published magnetic data, provide an updated identification of linear magnetic anomalies in the northern Arabian Sea from the Owen Fracture Zone in the west to the Laxmi...

  12. The missing Northern European winter cooling response to Arctic sea ice loss

    Science.gov (United States)

    Screen, James A.

    2017-03-01

    Reductions in Arctic sea ice may promote the negative phase of the North Atlantic Oscillation (NAO-). It has been argued that NAO-related variability can be used an as analogue to predict the effects of Arctic sea ice loss on mid-latitude weather. As NAO- events are associated with colder winters over Northern Europe, a negatively shifted NAO has been proposed as a dynamical pathway for Arctic sea ice loss to cause Northern European cooling. This study uses large-ensemble atmospheric simulations with prescribed ocean surface conditions to examine how seasonal-scale NAO- events are affected by Arctic sea ice loss. Despite an intensification of NAO- events, reflected by more prevalent easterly flow, sea ice loss does not lead to Northern European winter cooling and daily cold extremes actually decrease. The dynamical cooling from the changed NAO is `missing', because it is offset (or exceeded) by a thermodynamical effect owing to advection of warmer air masses.

  13. Aerial Surveys of Endangered Whales in the Beaufort Sea, Chukchi Sea, and Northern Bering Sea.

    Science.gov (United States)

    1981-06-01

    16 Surveys of St Lawrence Island Nome to Point Barrow . . . 16 I Surveys of Barrow Area . . 18 Point Barrow to Deadhorse . . . 20 Surveys from...lease area, the Norton Basin - St . Lawrence Island area, the Hope Basin, and coastal portions of the Chukchi Sea. DESIGN The areas of study are listed...Bowhead Whale 314 857 Balaena mysticetus Beluga Whale** 284 3404 Delphinapterus leucas Gray Whale 2 6 Eschrichtius robustus Ring Seal 250 765 Phoca

  14. High-resolution Imaging of the Philippine Sea Plate subducting beneath Central Japan

    Science.gov (United States)

    Padhy, S.; Furumura, T.

    2016-12-01

    Thermal models predict that the oceanic crust of the young (PHP) is more prone to melting. Deriving a high-resolution image of the PHP, including slab melting and other features of the subduction zone, is a key to understand the basics of earthquake occurrence and origin of magma in complex subduction zone like central Japan, where both the PHP and Pacific (PAC) Plates subduct. To this purpose, we analyzed high-resolution waveforms of moderate sized (M 4-6), intermediate-to-deep (>150 km) PAC earthquakes occurring in central Japan and conducted numerical simulation to derive a fine-scale PHP model, which is not constrained in earlier studies. Observations show spindle-shaped seismograms with strong converted phases and extended coda with very slow decay from a group of PAC events occurring in northern part of central Japan and recorded by high-sensitivity seismograph network (Hi-net) stations in the region. We investigate the mechanism of propagation of these anomalous waveforms using the finite difference method (FDM) simulation of wave propagation through the subduction zone. We examine the effects on waveform changes of major subduction zone features, such as the melting of oceanic crust in PHP, serpentinized mantle wedge, hydrated layer on the PAC due to slab dehydration, and anomaly in upper mantle between the PAC and PHP. Simulation results show that the waveform anomaly is primarily explained by strong scattering and absorption of high-frequency energy by the low-velocity anomalous mantle structure, with a strong coda excitation yielding spindle-shaped waveforms. The data are secondarily explained by melting of PHP in the basaltic crust. The location of the mantle anomaly is tightly constrained by the observation and evidence of PAC thinning in the region; these localized low-velocity structures aid in ascending the slab-derived fluids around the slab thinning. We expect that the results of this study will enhance our present understanding on the mechanism

  15. Gravity and geoid anomalies of the Philippine Sea: Evidence on the depth of compensation for the negative residual water depth anomaly

    Science.gov (United States)

    Bowin, C.

    1982-01-01

    A negative free-air gravity anomaly which occurs in the central part of the Philippine Sea was examined to determine the distribution and nature of possible regional mass excesses or deficiencies. Geoid anomalies from GEOS-3 observation were positive. A negative residual geoid anomaly consistent with the area of negative free-air gravity anomalies were found. Theoretical gravity-topography and geoid-topography admittance functions indicated that high density mantle at about 60 km dept could account for the magnitudes of the gravity and residual geoid anomaly and the 1 km residual water depth anomaly in the Philippine Sea. The negative residual depth anomaly may be compensated for by excess density in the uppermost mantle, but the residual geoid and regional free-air gravity anomalies and a slow surface wave velocity structure might result from low-density warm upper mantle material lying beneath the zone of high-density uppermost mantle. From a horizontal disk approximation, the depth of the low-density warm mantle was estimated to be on the order of 200 km.

  16. Modeling the Philippine Mobile Belt: Tectonic blocks in a deforming plate boundary zone

    Science.gov (United States)

    Galgana, G. A.; Hamburger, M. W.; McCaffrey, R.; Bacolcol, T. C.; Aurelio, M. A.

    2007-12-01

    The Philippine Mobile Belt, a seismically active, rapidly deforming plate boundary zone situated along the convergent Philippine Sea/Eurasian plate boundary, is examined using geodetic and seismological data. Oblique convergence between the Philippine Sea Plate and the Eurasian plate is accommodated by nearly orthogonal subduction along the Philippine Trench and the Manila Trench, as well as by strike-slip faulting along the Philippine Fault system. We develop a model of active plate boundary deformation in this region, using elastic block models constrained by known fault geometries, published GPS observations and focal mechanism solutions. We then present an estimate of block rotations, fault coupling, and intra-block deformation, based on the best-fit model that minimizes the misfit between observed and predicted geodetic vectors and earthquake slip vectors. Slip rates along the Philippine fault vary from ~22 - 36 mm/yr in the Central Visayas and about 10 to 40 mm/yr in Luzon, trending almost parallel to the fault trace. In northern Luzon, Philippine Fault splays accommodate transpressional strain. The Central Visayas block experiences convergence with the Sundaland block along the Negros Trench and the Mindoro-Palawan collision zone. On the eastern side of Central Visayas, sinistral strike-slip faulting occurs along the NNW-SSE-trending Philippine Fault. Mindanao Island in southern Philippines is dominated by east-verging subduction along the Cotabato Trench, and strain partitioning (strike- slip faulting with west-verging subduction) in eastern Mindanao along the southern Philippine Fault and Philippine Trench, respectively. Oblique active sinistral strike slip faults in Central and Eastern Mindanao that were hypothesized to be responsible for basin formation are obvious boundaries for tectonic blocks. Located south of Mindanao Island we define an adjoining oceanic block defined by the N-S trending complex dual subduction zone of Sangihe and Halmahera

  17. Novel Bartonella infection in northern and southern sea otters (Enhydra lutris kenyoni and Enhydra lutris nereis).

    Science.gov (United States)

    Carrasco, Sebastian E; Chomel, Bruno B; Gill, Verena A; Kasten, Rickie W; Maggi, Ricardo G; Breitschwerdt, Edward B; Byrne, Barbara A; Burek-Huntington, Kathleen A; Miller, Melissa A; Goldstein, Tracey; Mazet, Jonna A K

    2014-06-04

    Since 2002, vegetative valvular endocarditis (VVE), septicemia and meningoencephalitis have contributed to an Unusual Mortality Event (UME) of northern sea otters in southcentral Alaska. Streptococcal organisms were commonly isolated from vegetative lesions and organs from these sea otters. Bartonella infection has also been associated with bacteremia and VVE in terrestrial mammals, but little is known regarding its pathogenic significance in marine mammals. Our study evaluated whether Streptococcus bovis/equinus (SB/E) and Bartonella infections were associated with UME-related disease characterized by VVE and septicemia in Alaskan sea otter carcasses recovered 2004-2008. These bacteria were also evaluated in southern sea otters in California. Streptococcus bovis/equinus were cultured from 45% (23/51) of northern sea otter heart valves, and biochemical testing and sequencing identified these isolates as Streptococcus infantarius subsp. coli. One-third of sea otter hearts were co-infected with Bartonella spp. Our analysis demonstrated that SB/E was strongly associated with UME-related disease in northern sea otters (Pdetected in 45% (23/51) and 10% (3/30) of heart valves of northern and southern sea otters examined, respectively, it was not associated with disease. Phylogenetic analysis of the Bartonella ITS region allowed detection of two Bartonella species, one novel species closely related to Bartonella spp. JM-1, B. washoensis and Candidatus B. volans and another molecularly identical to B. henselae. Our findings help to elucidate the role of pathogens in northern sea otter mortalities during this UME and suggested that Bartonella spp. is common in sea otters from Alaska and California.

  18. Validation of SMOS sea ice thickness retrieval in the northern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Nina Maaß

    2015-02-01

    Full Text Available The Soil Moisture and Ocean Salinity (SMOS mission observes brightness temperatures at a low microwave frequency of 1.4 GHz (L-band with a daily coverage of the polar regions. L-band radiometry has been shown to provide information on the thickness of thin sea ice. Here, we apply a new emission model that has previously been used to investigate the impact of snow on thick Arctic sea ice. The model has not yet been used to retrieve ice thickness. In contrast to previous SMOS ice thickness retrievals, the new model allows us to include a snow layer in the brightness temperature simulations. Using ice thickness estimations from satellite thermal imagery, we simulate brightness temperatures during the ice growth season 2011 in the northern Baltic Sea. In both the simulations and the SMOS observations, brightness temperatures increase by more than 20 K, most likely due to an increase of ice thickness. Only if we include the snow in the model, the absolute values of the simulations and the observations agree well (mean deviations below 3.5 K. In a second comparison, we use high-resolution measurements of total ice thickness (sum of ice and snow thickness from an electromagnetic (EM sounding system to simulate brightness temperatures for 12 circular areas. While the SMOS observations and the simulations that use the EM modal ice thickness are highly correlated (r 2=0.95, the simulated brightness temperatures are on average 12 K higher than observed by SMOS. This would correspond to an 8-cm overestimation of the modal ice thickness by the SMOS retrieval. In contrast, if the simulations take into account the shape of the EM ice thickness distributions (r 2=0.87, the mean deviation between simulated and observed brightness temperatures is below 0.1 K.

  19. GRAIN SIZE DISTRIBUTION OF SEDIMENT IN THE NORTHERN EAST CHINA SEA AND THE RELATIONSHIP WITH THE SEA CURRENTS

    Institute of Scientific and Technical Information of China (English)

    LEI Kun; YANG Zuosheng; GUO Zhigang

    2002-01-01

    This paper discusses the relationship between the grain size distribution of sediment and currents in the northern East China Sea on the basis of the grain size analysis. The results show that grain size distribution of suspended sediment is controlled by the currents. Suspended sediment in the littoral water is finer than those in the open sea currents. Grain size distribution of surface sediment is affected by the sea currents to some extent. And the grain size of suspended sediment and surface sediment do not agree with each other in positions.

  20. Ra-228, Ra-226, Pb-210 and Po-210 variations in the water columns and the surface water plankton in the Luzon Strait and northern South China Sea

    Science.gov (United States)

    Chung, Y.; Lin, C.; Wang, P.; Su, Y.

    2006-12-01

    Profiles of Ra-228, Ra-226, Pb-210 and Po-210 were measured in the Luzon Strait (LS) and northern South China Sea (SCS) areas to delineate the exchanges between the western Philippine Sea (WPS) and the northern SCS waters across the LS. Plankton samples were also collected for Po-210 and Pb-210 measurements to assess the balance between the Po-210 excess over Pb-210 in the plankton and the deficit in the surface water. Profiles of Ra-228 and Ra-226 seem to indicate the out flow of the SCS water below the salinity minimum and above around 1500m depth, below which the WPS water flows into the SCS through the LS above a sill depth of about 2600m. This is consistent with previous studies conducted in the area. All the Pb-210 profiles show a strong subsurface maximum with higher activity in the LS area. This maximum is in large excess over its parent, Ra-226 due to atmospheric input. Po-210 profiles generally follow the associated Pb-210 profiles but with lower activities, showing Po-210 deficiency. Po-210 is strongly enriched over Pb-210 in the plankton samples with an activity ratio generally over 10 and up to 40. Both nuclides in the plankton are higher in the LS area, a trend similar to the surface water. The Po-210 excess in the plankton can account for at least 70 percent of the surface water deficit, part of which may be removed by sinking particles.

  1. Palaeoenvironmental changes from pollen record in deep sea core PC-1 from northern Okinawa Trough, East China Sea during the past 24 ka

    Institute of Scientific and Technical Information of China (English)

    XU HongYan; CHANG FengMing; LUO YunLi; SUN XiangJun

    2009-01-01

    A pollen record of core PC-1 from the northern Okinawa Trough, East China Sea (ECS), provides in-formation on vegetation and climate changes since 24 cal. kaBP. A total of 103 samples were palyno-logically analyzed at 8 cm intervals with a time resolution of 230 a. Four pollen zones are recognized: zone I (812-715 cm, 24.2-21.1 cal. kaBP), zone II (715-451 cm, 21.1 -15.2 cal. kaBP), zone Ⅲ (451 -251 cm, 15.2-10.8 cal. kaBP), zone Ⅳ (251-0 cm, 10.8-0.3 cal. kaBP), corresponding to Late MIS 3, Last Glacial Maximum (LGM), deglaciation and Holocene, respectively. The LGM is characterized by the dominance of herbs, mainly Artemisia, and high pollen influx, implying an open vegetation on the ex-posed continental shelf and e cool and dry climate. The deglaciation is a climate warming stage with Pinus percentage increased and Artemisia percentage decreased and a rapid sea-level rise. The Holo-cene is characterized by predominance of tree pollen with rapid increase in Castanea-Castanopsis in-dicating the development of mixed evergreen and deciduous broad-leaved forest and a warm, humid climate. Low pollen influx during the Holocene probably implies submergence of the continental shelf and retreat of the pollen source area. The vegetation indicated by pollen assemblage found in this up-per zone is consistent with the present vegetation found in Kyushu, Japan. Originating from the humid mountain area of North Luzon of the Philippines, Tasmania and New Zealand, Phyllocladus with spo-radic occurrence throughout PC-1 core probably suggests the influence of Palaeo-Kuroshio Current or intense summer monsoon. The observed changes in Pinus and Herbs percentage indicate fluctuations of the sea level, and high Pinus percentage corresponds to high sea level. Spectrum analysis of the pollen percentage record reveals many millennial-scale periodicities, such as periodicities of 6.8, 3.8, 2.2, 1.6 ka.

  2. Mineral provinces and matter provenance of the surficial sediments in the western Philippine Sea: implication for modern sedimentation in West Pacific marginal basin

    Institute of Scientific and Technical Information of China (English)

    REN Xiangwen; YAN Quanshu; SHI Xuefa; WANG Kunshan; JIANG Xiaoli

    2007-01-01

    The characteristics and distribution patterns of detrital minerals (0.063~0.125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment.The detrital mineral composition of 219 surface sediment samples was analysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces: (Ⅰ) province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau-Kyūshū Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate-acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau-Kyūshū Ridge. it is suggested that, (1) Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. (2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau (e.g.,Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. (3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.

  3. Long-term mesoscale variability of modelled sea-ice primary production in the northern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Letizia Tedesco

    2017-06-01

    Full Text Available We describe a new ocean-sea ice-biogeochemical model, apply it to the Bothnian Bay in the northern Baltic Sea for the time period 1991–2007 and provide the first long-term mesoscale estimates of modelled sea-ice primary production in the northern Baltic Sea. After comparing the available physical and biogeochemical observations within the study area and the time period investigated with the model results, we show the modelled spatial, intra- and interannual variability in sea-ice physical and biogeochemical properties and consider the main factors limiting ice algal primary production. Sea-ice permeability in the studied area was low compared with the polar oceans, which appeared to be a major reason for the generally low primary production rates. Although the sea ice was less saline in the northernmost parts of the basin, these parts were characterized by sea ice with a larger amount of habitable space, higher levels of photosynthetically active radiation and increased macronutrient availability near the coast, which favoured higher algal growth rates. Other parts of the southern central basin were mostly co-limited by less favourable light conditions (i.e., earlier ice breakups associated with fewer sunlight hours and lower seawater macronutrient concentrations than in the coastal zones. Although a change towards milder winters (i.e., reduced ice cover, thickness and length of the ice season was previously detected on a half-century timescale and could partly be seen here, analysis of the temporal evolution of sea-ice biogeochemical properties showed no significant trends over time, though these properties were characterized by large interannual variability.

  4. Faunal and biogeographic analysis of Syllidae (Polychaeta from Rovinj (Croatia, northern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Barbara Mikac

    2010-04-01

    Full Text Available Luigi MuscoThe study of hard-bottom Syllidae (Polychaeta of the Rovinj area provides an updated measure of syllid species diversity in the northern Adriatic Sea. Faunal research in the coldest Mediterranean sectors may also help to address possible ecological and biogeographical consequences arising from climate change. Thirty-nine species were found, of which 13 are new for the northern Adriatic, increasing the species recorded from the area from 53 to 66. Some newly recorded species are dominant and typical of warmer areas. The lack of previous taxonomic updates is responsible for the high number of new findings. However, the northern Adriatic Sea is possibly undergoing long-term changes, with modifications of diversity due to the establishment of warm-water species. Syllid fauna of Sveti Ivan Island and its bioclimatic affinity are, in fact, unexpectedly more similar to the ones of some southern Mediterranean areas than to those traditionally reported for the northern Adriatic.

  5. Manila, Philippines

    National Research Council Canada - National Science Library

    Fatima Arkin

    2015-01-01

    .... Not odd assignments, considering that in the Philippine capital and its suburbs, roughly 10 percent of the workforce is unemployed and, in Manila alone, about one-third of residents live in slums...

  6. State Recognition or State Appropriation? Land Rights and Land Disputes among the Bugkalot/Ilongot of Northern Luzon, Philippines

    Directory of Open Access Journals (Sweden)

    Shu-Yuan Yang

    2012-04-01

    Full Text Available The Bugkalot/Ilongot were awarded the Certificate of Ancestral Domain Title (CADT issued by the National Commission on Indigenous Peoples in a joyful celebration on February 24, 2006. The CADT is a contemporary assertion of indigenous peoples’ ability to negotiate claims to land, livelihood, and autonomy within the nation-state. So far, however, the acquisition of the Bugkalot/Ilongot CADT has not made any substantial difference in the everyday lives of the people of Ġingin, a settlement located at the heartland of the Bugkalot area. Not only does the trend of in-migration of lowland settlers and other indigenous groups continue, there are heightening social tensions caused by growing numbers of land-grabbing incidents among the Bugkalot themselves. This issue is examined in the context of state-promoted settlement projects, the advance of capitalism, and the process of commodification, which have given rise to a new notion of exclusive landownership. State provision of land rights and capitalist market forces have combined to shape land relations in new and often surprising ways. By exposing some of the diverse and changing forms of dispossession, as well as the failure of barangay officials and government agencies in mediating and resolving land disputes, this article questions whether the seemingly novel avenues that the Philippine state has taken to “legitimate” indigenous peoples’ rights, in practice, actually extend state control.

  7. Northern Mariana Islands Marine Monitoring Team Sea Temperature Measurements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site specific monitoring of sea temperature is conducted using submersible temperature dataloggers at selected sites and depths around the islands of Saipan and Rota.

  8. Three-dimensional numerical modeling of temperature and mantle flow fields associated with subduction of the Philippine Sea plate, southwest Japan

    Science.gov (United States)

    Ji, Yingfeng; Yoshioka, Shoichi; Matsumoto, Takumi

    2016-06-01

    We investigated temperature and mantle flow distributions associated with subduction of the Philippine Sea (PHS) plate beneath southwest Japan, by constructing a three-dimensional parallelepiped model incorporating a past clockwise rotation, the bathymetry of the Philippine Sea plate, and distribution of the subducting velocity within its slab. The geometry of the subducting plate was inferred from contemporary seismic studies and was used as a slab guide integrated with historical plate rotation into the 3-D simulation. Using the model, we estimated a realistic and high-resolution temperature field on the subduction plate interface, which was constrained by a large number of heat flow data, and attempted to clarify its relationship with occurrences of megathrust earthquakes, long-term slow slip events (L-SSEs), and nonvolcanic low-frequency earthquakes (LFEs). Results showed that the oblique subduction coupled with the 3-D geometry of subducting PHS plate was a key factor affecting the interplate and intraplate temperature distributions, leading to a cold anomaly in the plate interface beneath western Shikoku, the Bungo Channel, and the Kii Peninsula. Temperatures in the slab core in these regions at a depth near the continental Moho were nearly 200°C lower than that in eastern Shikoku, indicating a high thermal lateral heterogeneity within the subducting plate. The geothermal control of the LFEs beneath western Shikoku was estimated to be within a range from 400 to 700°C, and the interplate temperature for the L-SSEs with a slip larger than 15 cm beneath the Bungo Channel was estimated to be approximately 350-500°C. A large horizontal temperature gradient of 2.5 ~ °C/km was present where the LFEs occurred repeatedly. The steep temperature change was likely to be related to the metamorphic phase transformation from lawsonite or blueschist to amphibolite of hydrous minerals of the mid-ocean ridge basalt of the subducting PHS plate.

  9. MIGRATORY NETWORK AND POPULATION STATUS OF ARDEIDAE IN NORTHERN AZOV SEA REGION

    Directory of Open Access Journals (Sweden)

    Peresadko L. V.

    2012-06-01

    Full Text Available The migratory network of eight Ardeidae species was considered regards the field research in Northern Azov Sea region in 1988-2003. Some 5405 individuals were banded and 44 recovery reports were obtained. The main route of autumn heron migrations was the south-western, the main wintering site were the Levant, Central and West Africa. It was proved the herons belong to local populations which are the part of large Azov-Black Sea geographical populations.

  10. Conrad Deep, Northern Red Sea: Development of an early stage ocean deep within the axial depression

    Science.gov (United States)

    Ehrhardt, A.; Hübscher, C.; Gajewski, D.

    2005-12-01

    The northern Red Sea represents a continental rift in its final stage and close to the following stage of seafloor spreading. Ocean deeps within the evaporites of the northern Red Sea seem to accompany this process and are thought to be surface expressions of first seafloor spreading cells. In 1999 during R/V Meteor cruise M44/3 a dense multichannel seismic and hydroacoustic survey was conducted in order to investigate the initial formation process of the Conrad Deep, a young northern Red Sea deep. Three seismic units were differentiated in the uppermost part of the Miocene evaporites and the Plio-Quaternary sediments. A weakness zone within the evaporites, oblique to the main extension direction of the Red Sea, led to a transtension process within the evaporites that opened the deep. Its formation is directly related to the emplacement of magmatic bodies in its vicinity and the focusing of the Red Sea extension to the axial depression. The Conrad Deep is an intra-evaporite basin that cannot be regarded as surficial expression of a basement structure as the low shear strength of the evaporites decouple the sediments from the basement. However, its position and shape in combination with the accompanying geophysical anomalies point to a strong correlation with the Red Sea rifting process.

  11. Sea-surface salinity variations in the Northern Caribbean Sea across the mid-Pleistocene transition

    Directory of Open Access Journals (Sweden)

    S. Sepulcre

    2010-06-01

    Full Text Available This study aimed at documenting climate changes in tropical area in response to the Mid-Pleistocene Transition (MPT by reconstructing past hydrologic variations in the Northern Caribbean Sea and its influence on the stability of the Atlantic Meridional Overturning Circulation (AMOC during the last 940 kyr. Using core MD03-2628, we estimated past changes in sea surface salinity (SSS using Δδ18O, the difference between the modern and the past δ18O of seawater (obtained by combining alkenone thermometer data with the δ18O of the planktonic foraminifera Globigerinoides ruber (white and corrected for ice-sheet volume effects. Today, the lowest SSS values in the studied area are associated with the northernmost location of the Inter-Tropical Convergence Zone (ITCZ. The Δδ18O record exhibits glacial/interglacial cyclicity with higher values during all glacial periods spanning the last 940 kyr, indicating increased SSS. At a longer timescale, the Δδ18O exhibits a shift toward lower values for interglacial periods during the last 450 kyr, when compared to interglacial stages older than 650 kyr. A rise in SSS during glacial stages may be related to the southernmost location of the ITCZ, which is induced by a steeper interhemispheric temperature gradient and associated with reduced northward cross equatorial oceanic transport. Therefore, the results suggest a permanent link between the tropical salinity budget and the AMOC during the last 940 kyr. Following the MPT, lower salinities during the last five interglacial stages indicate a northernmost ITCZ location, forced by changes in the interhemispheric temperature gradient that is associated with the poleward position of Southern Oceanic Fronts that amplified the transport of heat and moisture to the North Atlantic. These processes may have contributed to amplification of the climate cycles that

  12. Sea-surface salinity variations in the northern Caribbean Sea across the Mid-Pleistocene Transition

    Directory of Open Access Journals (Sweden)

    S. Sepulcre

    2011-02-01

    Full Text Available By reconstructing past hydrologic variations in the Northern Caribbean Sea and their influence on the stability of the Atlantic Meridional Overturning Circulation (AMOC during the last 940 ka, we seek to document climate changes in this tropical area in response to the Mid-Pleistocene Transition (MPT. Using core MD03-2628, we estimated past changes in sea surface salinity (SSS using Δδ18O, the difference between the modern, and the past δ18O of seawater (obtained by combining alkenone thermometer data with the δ18O of the planktonic foraminifera Globigerinoides rube (white and corrected for ice-sheet volume effects. Today, the lowest SSS values in the area studied are associated with the northernmost location of the Inter-Tropical Convergence Zone (ITCZ. The Δδ18O record obtained from core MD03-2628 exhibits glacial/interglacial cyclicity with higher values during all glacial periods spanning the last 940 ka, indicating increased SSS. A long-term trend was also observed in the Δδ18O values that exhibited a shift toward lower values for interglacial periods during the last 450 ka, as compared to interglacial stages older than 650 ka. A rise in SSS during glacial stages may be related to the southernmost location of the ITCZ, which is induced by a steeper cross-equator temperature gradient and associated with reduced northward cross-equatorial oceanic transport. Therefore, the results suggest a permanent link between the tropical salinity budget and the AMOC during the last 940 ka. Following the MPT, lower salinities during the last five interglacial stages indicated a northernmost ITCZ location that was forced by changes in the cross-equator temperature gradient and that was associated with the poleward position of Southern Oceanic Fronts that amplify the transport of heat and moisture to the North Atlantic. These processes may have contributed to the amplification of the

  13. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2004-06-16 to 2004-08-13 (NODC Accession 0112212)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112212 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  14. 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 SHUMPU MARU in the Philippine Sea from 1998-08-19 to 1998-08-27 (NODC Accession 0112304)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112304 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1998-08-19 to...

  15. 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 SHUMPU MARU in the Philippine Sea from 1998-10-07 to 1998-10-15 (NODC Accession 0112305)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112305 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1998-10-07 to...

  16. 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 SHUMPU MARU in the Philippine Sea from 2000-08-17 to 2000-08-25 (NODC Accession 0112314)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112314 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-08-17 to...

  17. 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 MELVILLE in the North Pacific Ocean and Philippine Sea from 2013-03-21 to 2013-05-01 (NODC Accession 0117338)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117338 includes chemical, discrete sample, physical and profile data collected from MELVILLE in the North Pacific Ocean and Philippine Sea from...

  18. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from Kaiyo in the North Pacific Ocean and Philippine Sea from 1994-02-16 to 1994-02-24 (NCEI Accession 0143945)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0143945 includes discrete sample and profile data collected from Kaiyo in the North Pacific Ocean and Philippine Sea from 1994-02-16 to 1994-02-24....

  19. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the SHOYO in the North Pacific Ocean and Philippine Sea from 1994-11-01 to 1994-11-14 (NODC Accession 0115606)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115606 includes chemical, discrete sample, physical and profile data collected from SHOYO in the North Pacific Ocean and Philippine Sea from...

  20. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the RYOFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2001-10-10 to 2001-12-06 (NODC Accession 0115281)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115281 includes biological, chemical, discrete sample, physical and profile data collected from RYOFU MARU in the North Pacific Ocean, Philippine Sea...

  1. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean and Philippine Sea from 2002-11-13 to 2002-12-16 (NODC Accession 0112356)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112356 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean and Philippine Sea from...

  2. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2004-01-20 to 2004-02-06 (NODC Accession 0112210)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112210 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  3. pH, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the SHUMPU MARU in the Philippine Sea from 1992-02-25 to 1992-02-29 (NODC Accession 0115709)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115709 includes chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1992-02-25 to 1992-02-29...

  4. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the North Pacific Ocean and Philippine Sea from 1996-06-17 to 1996-07-02 (NODC Accession 0115016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115016 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the North Pacific Ocean and Philippine Sea from...

  5. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2002-01-17 to 2002-03-06 (NODC Accession 0115278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115278 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  6. 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 SHUMPU MARU in the Philippine Sea from 1999-07-09 to 1999-07-17 (NODC Accession 0112308)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112308 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-07-09 to...

  7. 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 RYOFU MARU in the North Pacific Ocean and Philippine Sea from 2000-06-20 to 2000-07-31 (NODC Accession 0112278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0112278 includes discrete sample and profile data collected from RYOFU MARU in the North Pacific Ocean and Philippine Sea from 2000-06-20 to...

  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 the KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2005-01-18 to 2005-02-24 (NODC Accession 0112213)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112213 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  9. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the RYOFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 1998-07-03 to 1998-07-31 (NODC Accession 0115285)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115285 includes biological, chemical, discrete sample, physical and profile data collected from RYOFU MARU in the North Pacific Ocean, Philippine Sea...

  10. 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 SHUMPU MARU in the Philippine Sea from 1998-07-09 to 1998-07-17 (NODC Accession 0112303)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112303 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1998-07-09 to...

  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 SHUMPU MARU in the Philippine Sea from 1999-04-28 to 1999-05-06 (NODC Accession 0112307)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112307 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-04-28 to...

  12. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2006-01-18 to 2006-02-06 (NODC Accession 0112328)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112328 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  13. 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 SHUMPU MARU in the Philippine Sea from 1999-01-21 to 1999-01-28 (NODC Accession 0112306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112306 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-01-21 to...

  14. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2006-06-14 to 2006-07-27 (NODC Accession 0112330)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112330 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  15. 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 SHUMPU MARU in the Philippine Sea from 1999-08-30 to 1999-09-06 (NODC Accession 0112309)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112309 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-08-30 to...

  16. 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 SHUMPU MARU in the Philippine Sea from 1998-04-22 to 1998-04-30 (NODC Accession 0112302)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112302 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1998-04-22 to...

  17. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2008-01-17 to 2008-02-28 (NODC Accession 0112334)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112334 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  18. 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 SHUMPU MARU in the Philippine Sea from 1999-10-06 to 1999-10-14 (NODC Accession 0112310)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112310 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-10-06 to...

  19. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2001-01-19 to 2001-03-09 (NODC Accession 0115321)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115321 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  20. 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 SHUMPU MARU in the Philippine Sea from 2000-06-28 to 2000-07-06 (NODC Accession 0112313)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112313 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-06-28 to...

  1. 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 SHUMPU MARU in the Philippine Sea from 2000-05-07 to 2000-05-15 (NODC Accession 0112312)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112312 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-05-07 to...

  2. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2003-02-25 to 2003-03-07 (NODC Accession 0112206)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112206 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  3. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2007-01-17 to 2007-02-26 (NODC Accession 0112331)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112331 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  4. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2003-06-25 to 2003-08-07 (NODC Accession 0112208)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112208 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  5. 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 SHUMPU MARU in the Philippine Sea from 2000-01-21 to 2000-01-28 (NODC Accession 0112311)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112311 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-01-21 to...

  6. 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 SHUMPU MARU in the Philippine Sea from 2000-10-11 to 2000-10-19 (NODC Accession 0112315)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112315 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-10-11 to...

  7. 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 KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2005-06-15 to 2005-08-12 (NODC Accession 0112215)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112215 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  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 the KEIFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2002-06-25 to 2002-08-01 (NODC Accession 0112204)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112204 includes biological, chemical, discrete sample, physical and profile data collected from KEIFU MARU in the North Pacific Ocean, Philippine Sea...

  9. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the RYOFU MARU in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2010-07-06 to 2010-08-22 (NODC Accession 0109921)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0109921 includes biological, chemical, discrete sample, physical and profile data collected from RYOFU MARU in the North Pacific Ocean, Philippine Sea...

  10. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the MELVILLE in the North Pacific Ocean and Philippine Sea from 2004-06-15 to 2004-08-27 (NODC Accession 0108080)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108080 includes chemical, discrete sample, physical and profile data collected from MELVILLE in the North Pacific Ocean and Philippine Sea from...

  11. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KAIYO-MARU in the North Pacific Ocean and Philippine Sea from 1994-01-07 to 1994-02-10 (NODC Accession 0115007)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115007 includes chemical, discrete sample, physical and profile data collected from KAIYO-MARU in the North Pacific Ocean and Philippine Sea from...

  12. Long-term development of inorganic nutrients and chlorophyll alpha in the open northern Baltic Sea.

    Science.gov (United States)

    Fleming-Lehtinen, Vivi; Laamanen, Maria; Kuosa, Harri; Haahti, Hannu; Olsonen, Riitta

    2008-03-01

    Eutrophication is an ongoing process in most parts of the Baltic Sea. This article reports on the changes during recent decades of several eutrophication-related variables in the open sea areas surrounding Finland (wintertime nutrient concentrations, wintertime nutrient ratios, and summer time chlorophyll alpha concentrations at the surface). The sum of nitrate- and nitrite-nitrogen ([NO3+NO2]-N) was observed to increase nearly fourfold in the Northern Baltic Proper and the Gulf of Finland and almost double in the Bothnian Sea from the 1960s until the 1980s or 1990s. The increase was followed by a decrease, which was modest in the two former subregions. Phosphate-phosphorus (PO4-P) concentrations followed a similar pattern in the Northern Baltic Proper (threefold increase and subsequent slight decrease) and Bothnian Sea (30% increase and subsequent decrease), but increased throughout the study in the Gulf of Finland, with the present concentration being threefold to the measurements made in the early 1970s. The PO4-P concentration decreased throughout the study in the Bothnian Bay. Silicate-silicon (SiO4-Si) concentrations decreased 30-50% from the early 1970s to the late 1990s and increased 20-40% thereafter in the Northern Baltic Proper, the Gulf of Finland, and the Bothnian Sea. Chlorophyll alpha showed an increase of over 150% in the Northern Baltic Proper and the Gulf of Finland from the 1970s until the early 2000s. In the Bothnian Sea the chlorophyll alpha concentration increased more than 180% from the late 1970s until the late 1990s, and decreased thereafter. According to these long-term observations, the Gulf of Finland and Northern Baltic Proper show clear signs of eutrophication, which may be emphasized by hydrographical changes affecting the phytoplankton communities and thus the algal biomass.

  13. Economic vulnerability to sea-level rise along the northern U.S. Gulf Coast

    Science.gov (United States)

    Thatcher, Cindy A.; Brock, John C.; Pendleton, Elizabeth A.

    2013-01-01

    The northern Gulf of Mexico coast of the United States has been identified as highly vulnerable to sea-level rise, based on a combination of physical and societal factors. Vulnerability of human populations and infrastructure to projected increases in sea level is a critical area of uncertainty for communities in the extremely low-lying and flat northern gulf coastal zone. A rapidly growing population along some parts of the northern Gulf of Mexico coastline is further increasing the potential societal and economic impacts of projected sea-level rise in the region, where observed relative rise rates range from 0.75 to 9.95 mm per year on the Gulf coasts of Texas, Louisiana, Mississippi, Alabama, and Florida. A 1-m elevation threshold was chosen as an inclusive designation of the coastal zone vulnerable to relative sea-level rise, because of uncertainty associated with sea-level rise projections. This study applies a Coastal Economic Vulnerability Index (CEVI) to the northern Gulf of Mexico region, which includes both physical and economic factors that contribute to societal risk of impacts from rising sea level. The economic variables incorporated in the CEVI include human population, urban land cover, economic value of key types of infrastructure, and residential and commercial building values. The variables are standardized and combined to produce a quantitative index value for each 1-km coastal segment, highlighting areas where human populations and the built environment are most at risk. This information can be used by coastal managers as they allocate limited resources for ecosystem restoration, beach nourishment, and coastal-protection infrastructure. The study indicates a large amount of variability in index values along the northern Gulf of Mexico coastline, and highlights areas where long-term planning to enhance resiliency is particularly needed.

  14. Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study - Part 2: Philippine receptor observations of fine-scale aerosol behavior

    Science.gov (United States)

    Reid, Jeffrey S.; Lagrosas, Nofel D.; Jonsson, Haflidi H.; Reid, Elizabeth A.; Atwood, Samuel A.; Boyd, Thomas J.; Ghate, Virendra P.; Xian, Peng; Posselt, Derek J.; Simpas, James B.; Uy, Sherdon N.; Zaiger, Kimo; Blake, Donald R.; Bucholtz, Anthony; Campbell, James R.; Chew, Boon Ning; Cliff, Steven S.; Holben, Brent N.; Holz, Robert E.; Hyer, Edward J.; Kreidenweis, Sonia M.; Kuciauskas, Arunas P.; Lolli, Simone; Oo, Min; Perry, Kevin D.; Salinas, Santo V.; Sessions, Walter R.; Smirnov, Alexander; Walker, Annette L.; Wang, Qing; Yu, Liya; Zhang, Jianglong; Zhao, Yongjing

    2016-11-01

    The largest 7 Southeast Asian Studies (7SEAS) operations period within the Maritime Continent (MC) occurred in the August-September 2012 biomass burning season. Data included were observations aboard the M/Y Vasco, dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for September 2012. At these locations, the Vasco observed MC smoke and pollution entering the southwest monsoon (SWM) monsoonal trough. Here we describe the research cruise findings and the finer-scale aerosol meteorology of this convectively active region. This 2012 cruise complemented a 2-week cruise in 2011 and was generally consistent with previous findings in terms of how smoke emission and transport related to monsoonal flows, tropical cyclones (TC), and the covariance between smoke transport events and the atmosphere's thermodynamic structure. Biomass burning plumes were usually mixed with significant amounts of anthropogenic pollution. Also key to aerosol behavior were squall lines and cold pools propagating across the South China Sea (SCS) and scavenging aerosol particles in their path. However, the 2012 cruise showed much higher modulation in aerosol frequency than its 2011 counterpart. Whereas in 2011 large synoptic-scale aerosol events transported high concentrations of smoke into the Philippines over days, in 2012 measured aerosol events exhibited a much shorter-term variation, sometimes only 3-12 h. Strong monsoonal flow reversals were also experienced in 2012. Nucleation events in cleaner and polluted conditions, as well as in urban plumes, were observed. Perhaps most interestingly, several cases of squall lines preceding major aerosol events were observed, as opposed to 2011 observations where these lines largely scavenged aerosol particles from the marine boundary layer. Combined, these observations indicate pockets of high and low particle counts that are not uncommon in the region. These perturbations are difficult to observe by satellite and very difficult to model

  15. Influence of northeasterly trade winds on intensity of winter bloom in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Dwivedi, R.M.; Raman, M.; Parab, S.; Matondkar, S.G.P.; Nayak, S.

    , University of Pune for help and su g- gestions. Received 22 July 2005; revised accepted 20 January 2006 In fluence of northeasterly trade winds on inte n sity of winter bloom in the Northern Arabian Sea R. M. Dwivedi 1, *, Mini Raman 1...

  16. Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea

    NARCIS (Netherlands)

    Franeker, van J.A.; Blaize, C.; Danielsen, J.

    2011-01-01

    The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of

  17. Waves in the nearshore waters of northern Arabian Sea during the summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Singh, J.; Pednekar, P.S.; Gowthaman, R.

    % of the wave height at the measurement location is due to the swells arriving from the south-west and the remaining is due to the seas from south-west to north-west. Wave age of the measured data indicates that the waves in the nearshore waters of northern...

  18. Zooplankton standing stock, community structure and diversity in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Srivastava, Y.

    The effects of large scale oil spill, which occurred during the Gulf War in 1991 on zooplankton standing stock, community structure and diversity in the northern Arabian Sea were studied. Surface (1-0 m) and vertical zooplankton hauls (200-0 m, 250...

  19. Variability in growth rates of larval haddock in the northern North Sea

    DEFF Research Database (Denmark)

    Gallego, A.; Heath, M.R.; Basford, D.J.

    1999-01-01

    The large-scale distribution of haddock (Melanogrammus aeglefinus) larvae in the northern North Sea was mapped in a grid survey carried out in late April 1996. A drifting buoy was deployed in the centre of one of the areas of concentration of larvae located off the east coast of the Shetland Isles...

  20. Carbon cycling in the northern Arabian Sea during the northeast monsoon: Significance of salps

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; Sarma, V.V.S.S.; Jayakumar, D.A.

    Winter cooling and mixing brings nutrients (nitrate and phosphate) to the surface waters over large parts of the northern Arabian Sea, but the rates of primary production as well as carbon export from the euphotic zone are not especially high during...

  1. Winds observed in the Northern European seas with wind lidars, meteorological masts and satellite

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Stein, D.; Peña, Alfredo

    2013-01-01

    that for specific conditions, e.g. very stable atmosphere, the wind profiles can be heavily influenced by the boundary layer height at the 100 m level in the northern European seas. A very interesting part of the analysis includes the shear exponent (alpha) calculated during seasons, during 24-hours and for 12 wind...

  2. Spatial and temporal variability of winds in the Northern European Seas

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Badger, Merete; Hahmann, Andrea N.

    2013-01-01

    Satellite data are used to characterize the near-surface winds over the Northern European Shelf Seas. We compare mean winds from QuikSCAT with reanalysis fields from the Weather Research and Forecasting (WRF) model and in situ data from the FINO-1 offshore research mast. The aim is to evaluate...

  3. Sea Cucumber Fishery and Trade in Sta. Cruz, Davao Del Sur, Philippines: Supply Chains and Cost-Benefit Analyses

    OpenAIRE

    Shuck, Vlademir A.; Rod Norbert D. Mondoyo; Acuňa, Thaddeus R.; Ruth U. Gamboa

    2013-01-01

    In the country, sea cucumbers are exploited almost exclusively for export. It is harvested in three ways; commercial fishing, artisanal fishing and gleaning. These methods provide disproportionate economic benefits to these players in the supply chain. In this study, sea ranching, a new culture system for sea cucumber was analyzed in terms of its economic and commercial viability. Under the sea ranching system Holothuriascabra(sandfish) is the species being raised mainly due to its high econo...

  4. Hyperstratification following glacial overturning events in the northern Arabian Sea

    NARCIS (Netherlands)

    Reichart, G.-J.; Brinkhuis, H.; Huiskamp, F.; Zachariasse, W.J.

    2004-01-01

    [1] Correlations between Arabian Sea organic carbon and GISP2 d18O records indicate a pronounced oxygen minimum zone (OMZ) during interstadials, whereas well-oxygenated conditions prevailed during stadials. Local deep winter mixing ventilated intermediate water during the coldest stadials, correspon

  5. Collision processes at the northern margin of the Black Sea

    Science.gov (United States)

    Gobarenko, V. S.; Murovskaya, A. V.; Yegorova, T. P.; Sheremet, E. E.

    2016-07-01

    Extended along the Crimea-Caucasus coast of the Black Sea, the Crimean Seismic Zone (CSZ) is an evidence of active tectonic processes at the junction of the Scythian Plate and Black Sea Microplate. A relocation procedure applied to weak earthquakes (mb ≤ 3) recorded by ten local stations during 1970-2013 helped to determine more accurately the parameters of hypocenters in the CSZ. The Kerch-Taman, Sudak, Yuzhnoberezhnaya (South Coast), and Sevastopol subzones have also been recognized. Generalization of the focal mechanisms of 31 strong earthquakes during 1927-2013 has demonstrated the predominance of reverse and reverse-normal-faulting deformation regimes. This ongoing tectonic process occurs under the settings of compression and transpression. The earthquake foci with strike-slip component mechanisms concentrate in the west of the CSZ. Comparison of deformation modes in the western and eastern Crimean Mountains according to tectonophysical data has demonstrated that the western part is dominated by strike-slip and normal- faulting, while in the eastern part, reverse-fault and strike-slip deformation regimes prevail. Comparison of the seismicity and gravity field and modes of deformation suggests underthusting of the East Black Sea Microplate with thin suboceanic crust under the Scythian Plate. In the Yuzhnoberezhnaya Subzone, this process is complicated by the East Black Sea Microplate frontal part wedging into the marginal part of the Scythian Plate crust. The indentation mechanism explains the strong gravity anomaly in the Crimean Mountains and their uplift.

  6. Evolution of Titan's Seas and Lakes during Northern Spring

    Science.gov (United States)

    Sotin, C.; Lawrence, K. J.; Le Mouelic, S.; MacKenzie, S.; Barnes, J. W.; Brown, R. H.; Cornet, T.; Rodriguez, S.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.; Soderblom, J. M.

    2014-12-01

    Titan is the only body in the solar system, besides Earth, to have stable liquid seas at its surface [1]. The three main seas, known as Kraken Mare, Ligeia Mare, and Punga Mare are located at the North Pole where they cover a surface area of 500,000-, 126,000-, and 50,000-km2, respectively. In addition, several hundreds of small lakes are present, raising the questions of their relationships with the large seas. These hydrocarbon lakes and seas can be better imaged at optical wavelengths as the season moves towards summer solstice. At the same time, the North Pole area is receiving more solar light, which modifies the atmospheric circulation. Global Circulation Models (GCMs) predict stronger winds, more evaporation, and formation of methane clouds [2]. The Visual and Infrared Mapping Spectrometer (VIMS) has observed the North Pole area during several high inclined flybys. Mosaics in seven infrared atmospheric windows have been constructed. Several units can be distinguished by their surface albedo. The 5-micron bright unit has been interpreted as evaporitic material based on its location relative to the lakes and seas [3]. The spectral characteristics cannot be matched by a simple mixture of water ice and 'typical Titan organic material' known as tholins. The composition of these different units is therefore still enigmatic. In addition, some of the spectral characteristics may be related to the texture of the units. The few passes over the North Pole have allowed the VIMS team to image some places several times looking for changes on the surface or/and in the lower atmosphere. Although GCMs predict evaporation of the seas and lakes and the formation of methane clouds [2], neither changes in the shorelines, nor clouds have been identified. Very recent specular reflection observations suggest the formation of waves on Punga [4], and therefore more active winds. In addition, the VIMS recently observed a brightening of the area between Punga, Kraken and Ligeia

  7. The deep thermal characteristic of continental margin of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Heat flow plays an important role in the study of thermal structure and thermal evolution of continental margin of the northern South China Sea. The analysis of heat flow value shows that margin heat flow in the northern South China Sea is relatively high setting, but the percentage of crustal heat flow is lower than 35% in terrestrial heat flow. The terrestrial heat flow exhibited a current of rise from the Northern Continental Margin to the Southern Central Basin. However, the proportion of crustal heat flow in terrestrial heat flow slowly dropped down in the same direction. It is suggested that the main factor causing high heat flow setting is the moving up of hot material from asthenosphere.

  8. The missing Northern European winter cooling response to Arctic sea ice loss

    Science.gov (United States)

    Screen, James A.

    2017-01-01

    Reductions in Arctic sea ice may promote the negative phase of the North Atlantic Oscillation (NAO−). It has been argued that NAO-related variability can be used an as analogue to predict the effects of Arctic sea ice loss on mid-latitude weather. As NAO− events are associated with colder winters over Northern Europe, a negatively shifted NAO has been proposed as a dynamical pathway for Arctic sea ice loss to cause Northern European cooling. This study uses large-ensemble atmospheric simulations with prescribed ocean surface conditions to examine how seasonal-scale NAO− events are affected by Arctic sea ice loss. Despite an intensification of NAO− events, reflected by more prevalent easterly flow, sea ice loss does not lead to Northern European winter cooling and daily cold extremes actually decrease. The dynamical cooling from the changed NAO is ‘missing', because it is offset (or exceeded) by a thermodynamical effect owing to advection of warmer air masses. PMID:28262679

  9. Unusual phytoplankton bloom phenology in the northern Greenland Sea during 2010

    Science.gov (United States)

    Qu, Bo; Gabric, Albert J.; Lu, Zhifeng; Li, Hehe; Zhao, Li

    2016-12-01

    Arctic marine ecosystems are disproportionately impacted by global warming. Sea ice plays an important role in the regional climate system and the loss of perennial sea ice has diverse ecological implications. Here we investigate the causes of an unusually early and strong phytoplankton bloom in the northern Greenland Sea (20°W-10°E, 75°N-80°N) during the 2010 season. In order to better understand the anomalous bloom in 2010, we examine the correlation between satellite-derived biomass and several possible environmental factors for the period 2003-2012. Results show that the timing of sea ice melt played an important role in promoting the growth of phytoplankton. Multivariate lagged regression analysis shows that phytoplankton biomass (CHL) is correlated with ice concentration (ICE) and ice melting, as well as sea surface temperature (SST) and photosynthetically active radiation (PAR). During 2010, the spring peak in biomass came much earlier and achieved a higher value than most other years in the satellite archive record, which was due to earlier and more extensive sea ice melt in that year. Relative lower SST and PAR in spring and early summer in year 2010 associated with a persistent negative North Atlantic Oscillation (NAO) index were possible drivers of the bloom. Wind direction changed from the southeast to southwest direction in spring, possibly transporting nutrient enriched melt runoff from glaciers on Greenland and other sources from the south to northern coastal regions.

  10. Some Aspects of the Population Biology of the Green Tiger Prawn Penaeus semisulcatus (De Haan, 1844 from Pilar and Capiz Bays, Northern Panay, West Central Philippines

    Directory of Open Access Journals (Sweden)

    Karen A Villarta

    2006-06-01

    Full Text Available This study is a first report on the population biology of the green tiger prawn Penaeus semisulcatus (de Haan from northern Panay, west central Philippines. The study was conducted for eight months (May to December 2002 whereby total lengths of both male and female P. semisulcatus of various sizes were measured monthly from the catches of municipal trawlers operating at Pilar and Capiz Bays. Based on the Bhattacharya method, a mean growth rate of 0.78 ± 0.28 and 1.45 ± 0.39 mm/day were estimated for males and females, respectively. Using the ELEFAN I method, growth parameters derived for males were L∞ = 263 mm, k = 0.7/yr and a growth index (Ø' of 4.69. On the other hand, growth parameters derived for females were L∞ = 271 mm, k = 1.6/yr and a growth index (Ø' of 5.07.Based on length-converted catch curve analysis, the total mortality (Z of the male population is estimated to be 3.61/yr while that of the females is 5.65/yr. Male prawns showed a higher exploitation rate (0.53 compared to that of the females (0.35 indicating the susceptibility of males to fishing. This study also revealed that trawlers in Pilar and Capiz Bays are already getting small sizes of prawns, without allowing them to reach sexual maturity. Hence, there is a need to increase the present mesh size (2.5 cm of the cod end of trawls in order to avoid growth overfishing, which may occur with continued increase in fishing effort. Furthermore, the recruitment pattern showed two pulses of unequal strengths and time, dividing the year into a 7-5 month pattern. The said pattern, especially for females, may have resulted from a major and minor spawning peak of the said species during the months of June-September and January.

  11. Linking the northern hemisphere sea-ice reduction trend and the quasi-decadal arctic sea-ice oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J. [University of Alaska Fairbanks, International Arctic Research Center, Alaska (United States); Ikeda, M. [Hokkaido University, Graduate School of Environmental Earth Science, Sapporo (Japan); Zhang, S. [University of Alaska Fairbanks Fairbanks, Department of Mathematical Sciences, Alaska (United States); Gerdes, R. [Alfred-Wegener Institute for Polar Research, Bremerhaven (Germany)

    2005-02-01

    The nature of the reduction trend and quasi-decadal oscillation in Northern Hemisphere sea-ice extent is investigated. The trend and oscillation that seem to be two separate phenomena have been found in data. This study examines a hypothesis that the Arctic sea-ice reduction trend in the last three decades amplified the quasi-decadal Arctic sea-ice oscillation (ASIO) due to a positive ice/ocean-albedo feedback, based on data analysis and a conceptual model proposed by Ikeda et al. The theoretical, conceptual model predicts that the quasi-decadal oscillation is amplified by the thinning sea-ice, leading to the ASIO, which is driven by the strong positive feedback between the atmosphere and ice-ocean systems. Such oscillation is predicted to be out-of-phase between the Arctic Basin and the Nordic Seas with a phase difference of 3{pi}/4, with the Nordic Seas leading the Arctic. The wavelet analysis of the sea ice data reveals that the quasi-decadal ASIO occurred actively since the 1970s following the trend starting in the 1960s (i.e., as sea-ice became thinner and thinner), as the atmosphere experienced quasi-decadal oscillations during the last century. The wavelet analysis also confirms the prediction of such out-of-phase feature between these two basins, which varied from 0.62{pi} in 1960 to 0.25{pi} in 1995. Furthermore, a coupled ice-ocean general circulation model (GCM) was used to simulate two scenarios, one without the greenhouse gas warming and the other having realistic atmospheric forcing along with the warming that leads to sea-ice reduction trend. The quasi-decadal ASIO is excited in the latter case compared to the no-warming case. The wavelet analyses of the simulated ice volume were also conducted to derive decadal ASIO and similar phase relationship between the Arctic Ocean and the Nordic Seas. An independent data source was used to confirm such decadal oscillation in the upper layer (or freshwater) thickness, which is consistent with the model

  12. Oceanization starts from below during continental rupturing in the northern Red Sea

    Science.gov (United States)

    Cai, Y.; Ligi, M.; Bonatti, E.; Bosworth, W.; Cipriani, A.; Palmiotto, C.; Rasul, N. M.; Ronca, S.; Sanfilippo, A.; Seyler, M.; Nomani, S.; AlQutub, A. S.

    2015-12-01

    The role of magmatism in continental rupturing and in the birth of a new ocean is not well understood. Continental rupture can take place with intense and voluminous volcanism, as in the Southern Red Sea or in a relatively amagmatic mode, as in the Northern Red Sea. Mantle upwelling and melting may be affected by the south to north decreasing opening rate of the Red Sea and by the influence of the Afar plume, also decreasing from south to north. The tholeiitic basalts of the Red Sea spreading system contrast with the extensive Cenozoic basaltic lava fields of the western part of the Arabian peninsula that form one of the largest alkali basalt provinces in the world. In order to establish possible relationship between the Red Sea rift evolution and the western Saudi Arabia intraplate alkali volcanism, field work was carried out on Lunayyir, Ishara, al Kura and Khaybar volcanic fields. Collected samples cover a wide range of chemical diversity (from olivine basalt to trachyte) and span over a 20 Ma interval. We attempt a comparison of the geochemistry of igneous rocks from western Arabia dykes and volcanic fields with those from the Red Sea axis and from the islands of Zabargad and Brothers in the northern Red Sea, that represent basaltic melts injected into the thinned continental crust before continental rupturing and initiation of seafloor spreading. Gabbros drilled in the western Red Sea and exposed on the Brothers islands suggest that continental break up in the northern Red Sea, a relatively non-volcanic rift, is preceded by intrusion of oceanic-type basaltic melts that crystallize at progressively shallower crustal depths as rifting progresses towards continental break-up. A seismic reflection profile running across the central part of the southern Thetis basin shows a ~5 km wide reflector that marks the roof of a magma chamber located ~3.5 km below seafloor. The presence of a few kilometers deep subrift magma chamber soon after the initiation of oceanic

  13. Jurassic domes in the North Sea - northern North Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Surlyk, F. [Univ. of Copenhagen, Geological Inst., Copenhagen (Denmark)

    1996-12-31

    The stratigraphic and tectonic evolution of the Jurassic of East Greenland, the Norwegian Shelf and the North Sea is remarkably similar. A major Middle Jurassic unconformity occurs in all three areas. In the North Sea it is commonly termed the `Mid-Cimmerian Unconformity` and is characterized by progressive truncation of the underlying section towards a centre at the triple junction between the Central Graben, Viking Graben and Moray Firth. Strata above the unconformity show a progressive Late Aalenian-Early Kimmeridgian onlap in the same direction. These relations have been interpreted as caused by Early Jurassic uplift and of a major thermal dome in the central North Sea, followed by Medial and Late Jurassic rifting, erosion, deflation and transgression of the dome. The East Greenland unconformity shows progressive truncation of underlying strata from south to north, and Bajocian to Callovian onlap in the same direction. The same pattern seems to be developed on the conjugate Norwegian margin. This suggests the possibility that the three unconformities have similar causes for their development. It is proposed that major rift domes formed in the Central North Sea and in the Greenland-Norway seaway in Early Jurassic times. The domes were eroded and gradually deflated during Medial Jurassic times and were finally submerged by the Late Oxfordian-Kimmeridgian. They were associated with volcanism and rifting which was delayed with respect to dome initiation. Roughly contemperaneous domes were present west of Britain, north of the Porcupine Seabight, and in Scania, southern Sweden, as reflected by development of asymmetrical unconformities showing progressive truncation of underlying strata, onlap of overlying Jurassic strata, and associated intrusive and extrusive volcanism. The domes are related to impingement of the heads of transient mantle plumes at the base of the lithosphere. The associated unconformities are thus of non-eustatic nature. Domal uplift and

  14. The Holocene Records of Glycerol Dialkyl Glycerol Tetraethers From the Northern Chukchi Sea

    Science.gov (United States)

    Park, Y.; Yamamoto, M.; Nam, S.; Polyak, L. V.

    2013-12-01

    We analyzed glycerol dialkyl glycerol tetraethers (GDGTs) in Cores HOTRAX 05-01 JPC5 and JPC 8, and ARA02B 01-GC in the northern Chukchi Sea. All of the three cores showed a similar changing pattern in GDGT composition during the Holocene. In the beginning of early Holocene, both isoprenoid and branched GDGT concentrations were low, and BIT and CBT were relatively high. The similar composition is found in modern sediments from the western Arctic Ocean north of 75°N, suggesting that the northern Chukchi Sea was covered by perennial sea ice. GDGT concentration increased, and BIT and CBT decreased during the early Holocene and reached the same level as those in modern sediments at 8 ka. TEX86 and CBT/MBT indices showed millennial-scale variation. We interpret that these proxies did not simply indicate temperatures but were affected by the relative contribution of different sediment sources. Millennial-scale variability likely reflected changes in sediment transport in the northern Chukchi Sea.

  15. The carbon budget in the northern Adriatic Sea, a winter case study

    Science.gov (United States)

    Catalano, G.; Azzaro, M.; Bastianini, M.; Bellucci, L. G.; Bernardi Aubry, F.; Bianchi, F.; Burca, M.; Cantoni, C.; Caruso, G.; Casotti, R.; Cozzi, S.; Del Negro, P.; Fonda Umani, S.; Giani, M.; Giuliani, S.; Kovacevic, V.; La Ferla, R.; Langone, L.; Luchetta, A.; Monticelli, L. S.; Piacentino, S.; Pugnetti, A.; Ravaioli, M.; Socal, G.; Spagnoli, F.; Ursella, L.

    2014-07-01

    This paper presents a winter carbon budget for the northern Adriatic Sea, obtained through direct measurements during two multidisciplinary cruises and literature data. A box model approach was adopted to integrate estimates of stocks and fluxes of carbon species over the total area. The oligotrophy at the basin scale and the start of primary productivity well before the onset of spring stratification were observed. In winter, the system underwent a complete reset, as the mixing of water masses erased any signal of previous hypoxia or anoxia episodes. The northern Adriatic Sea was phosphorus depleted with respect to C and N availability. This fact confirms the importance of mixing with deep-sea water for P supply to biological processes on the whole. Despite the abundant prokaryotic biomass, the microbial food web was less efficient in organic C production than phytoplankton. In the upper layer, the carbon produced by primary production exceeded the fraction respired by planktonic community smaller than 200 µm. On the contrary, respiration processes prevailed in the water column below the pycnocline. The carbon budget also proved that the northern Adriatic Sea can be an effective sink for atmospheric CO2 throughout the entire winter season.

  16. Rock magnetic response to climatic changes in west Philippine Sea for the last 780 ka:Discussion based on relative paleointensity assisted chronology

    Institute of Scientific and Technical Information of China (English)

    Shulan GE; Xuefa SHI; Gang YANG; Yonghua WU

    2008-01-01

    We conducted rock magnetic and paleomagnetic research on two deep-sea sediment cores from the west Philippine Sea,located to the east of Benham Rise With the length of 4 m and water depth of over 5000 m.At the bottom of core 146 occurs a reversal of inclination and deflection of relative declination,which is recognized as BrunhesMatuyama Polarity Boundary(MBPB).No reversal occurs in core 89.which implies a younger bottom age than that of core 146.Rock magnetic results reveal-magnetic uniformities in mineralogy,concentration and grain size along the two cores,thus relative paleointensity variations are acquired.The three normalizers-anhysteresis remanent magnetization(ARM),magnetic susceptibility(K)and saturation isothermal remanent magnetization(SIRM)are used for normalization to obtain relative Daleointensities.The three normalization results are averaged to indicate the paleoitensity of the cores and are further stacked together to get a synthetic curve for west Philippine Sea(named as WPS800 in this paper).Based on the magnetic correlation between cores and paleointensity to Sint800,we transfer the changes of rock magnetic parameters from depth to time.Furthermore,the astronomically tuned oxygen isotope from ODP site 1143 in the south China Sea is used for the glacial and interglacial indicator.Three concentration proxies(ARM,K and SIRM)and grain size indicators(KARM/SIRM,KARM/K)are examined according to the paleointensity-assisted chronology.The grain size changes in the two cores display a consistent pattem with the climatic changes embodied bv oxygen isotope.The magnetic sizes are usually coarser in glacial periods and finer in interglacial times,which may reflect the influence of chemical erosion rather than fining from sea level rising on the source sediment.Furthermore,the sub-peaks and subtroughs in interglaciations almost correspond with that of oxygen isotope records,which means sedimentation can refect the subtle changes in interglaciations.This kind

  17. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas

    Science.gov (United States)

    Sasaki, Hiroko; Matsuno, Kohei; Fujiwara, Amane; Onuka, Misaki; Yamaguchi, Atsushi; Ueno, Hiromichi; Watanuki, Yutaka; Kikuchi, Takashi

    2016-08-01

    The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll a concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic-benthic-type ecosystem to a pelagic-pelagic type.

  18. Preface to the Special Issue on "Geodynamics of Taiwan and the Philippines"

    Directory of Open Access Journals (Sweden)

    Win-Bin Cheng and Shou-Yeh Gong

    2015-01-01

    Full Text Available This special issue contains a collection of six papers dealing with the geology, geophysics, and tectonics of Taiwan and the Philippines. Most of these papers were presented at the fourth _ Earth Sciences International _ in Manila, Philippines, 8 - 9 June 2013. The tectonics of Taiwan and the Philippines are controlled mainly by three plates: the Indian, Eurasian, and Philippine Sea Plates. Taiwan and the Philippines are located next to each other in terms of geography and also plate tectonics. Luzon Island originated from the interactions between the South China Sea and Philippine Sea Plates. Taiwan was also created by collisions between the Philippine Sea Plate and Eurasian Plates. The convergence of these plates also results in many earthquakes and volcanic activities in the region. Both Taiwan and the Philippines face similar geological hazards, such as earthquakes, landslides, volcanic eruptions, and tsunamis.

  19. Pacific walrus (Odobenus rosmarus divergens resource selection in the Northern Bering Sea.

    Directory of Open Access Journals (Sweden)

    Chadwick V Jay

    Full Text Available The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%. Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea.

  20. Well log interpretation and seismic character of the cenozoic sequence in the northern Alboran Sea

    Science.gov (United States)

    Jurado, M. J.; Comas, M. C.

    1992-06-01

    Seismic stratigraphic and main lithological features of the sedimentary cover overlying the basement of the Alboran Sea were established via the analysis of commercial multichannel seismic surveys, geophysical well logs, and well data. Six seismic stratigraphics units (VI to I), bounded by unconformities, form the marine sediments that range in age from early Miocene to Quaternary. They are dated by extrapolation of commercial drilling results from the northern Alboran Sea. Volcanic activity is recorded within sedimentary sequences of units V to II. Undercompaction features are detected in the two basal units.

  1. Physical forcing of biological productivity in the northern Arabian Sea during the northeast monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Ramaiah, N.; Gauns, M.; Sarma, V.V.S.S.; Muraleedharan, P.M.; Raghukumar, S.; DileepKumar, M.; Madhupratap, M.

    ,M.J.W.,Kraay,G.W.,van-Bleijswijk,J.D.L.,Baars,M.A.,1997.Abundanceofbacterioplanktoninrelationto seasonal upwelling in the northwest Indian Ocean. Deep-Sea Research I: Oceanographic Research Papers 44, 425}449. Wishner,K.,Gowing,M.,Gelfman,C.,1998.Zooplanktonbiomassintheupper1000minthe...-1 *Correspondingauthor.fax:#91-832-223340. E-mail address:prasanna@csnio.ren.nic.in(S.P.Kumar). Deep-SeaResearchII48(2001)1115}1126 Physicalforcingofbiologicalproductivityinthe NorthernArabianSeaduringtheNortheastMonsoon S...

  2. Human health implications associated with mucilage in the northern Adriatic Sea.

    Science.gov (United States)

    Funari, E; Ade, P

    1999-01-01

    Mucilage in the northern Adriatic Sea is well known for its negative impact not only on the ecology of the affected area and on fishing activities but on tourism as well. The microhabitat mucilage creates in the sea can provide favourable conditions for the growth and/or survival of some environmental microorganisms that include human opportunistic pathogens. It also seems to favour the selective development of some marine toxic algae. Finally, mucilage can concentrate chemical contaminants from surrounding waters, hence increasing their bioaccumulation in seafoods. This paper examines the possible direct and indirect effects on human health of mucilage and other forms of marine aggregates.

  3. Effect of the Northern Sea Route Opening to the Shipping Activities at Malacca Straits

    Directory of Open Access Journals (Sweden)

    N.S.F. Abdul Rahman

    2014-12-01

    Full Text Available The opening of the Northern Sea Route as an alternative route for transporting cargoes between the Far East and Europe seems highly acceptable by shipping companies due to the great saving in fuel consumption, bunker cost, operating cost, emissions and journey time. This situation will not only affect the maritime business activity in the Straits of Malacca but also, the Malaysian economy in different perspectives when the vessels sail via the Suez Canal and the Indian Ocean are expected to decrease. The objective of this study is to analyse the implication in the opening of the Northern Sea Route on Maritime Sector of the Malaysian economy by using PESTEL analysis. The main scope is focusing more on the Malacca Straits shipping activity by using a number of parameters that have been obtained from Port Klang and Port Klang Authority through a set of questionnaires and interview sessions with industrial experts.

  4. [Deep sea trip of the ship crash Northern Force fleet].

    Science.gov (United States)

    Ushakov, I B; Bubeev, Iu A; Mazaĭkin, D N; Pisarev, A A

    2008-07-01

    A long-termed navy march of crash shupborn group of Northern Navy became a sign-oriented event in the life of the Armed Forces. After more then 10 years cessation this march signed recommencement of permanent Russia navy attendance in strategically important areas of the World Ocean. The authors highlight work of military-navy specialists in conditions of this march. The most important peculiarity of this march was participation of a hard aircraft carrier "Navy Admiral of the Soviet Union N.G.Kuznetsov". Activity of aircraft staff in carrying out the boardings and the deck starts requires the highest mobilization of all psycho-physiological resources. There was effectuated a complex medical-psychophysiological research of functional condition of aircraft and engineer staff of the group during the service. Also there was effectuated an operative recovery of functional condition among sailors and officers of the ship staff. Method of neuronsemantic diagnostics of psychological disadaptation and suicide risk was used during the analyze of groups of risk. The results of the analyze permitted to educe main psychotraumatizing factors, to form recommendations on psycho-correction, organization-educative measures taking into account individual peculiarities of motivation sphere and cognitive sensitivity. There were effectuated different trainings of moralities, communicativeness, strategy of negotiation and stress-managment in cooperation with the psychologist of the ship.

  5. 论菲律宾海板块大地构造分区%Discussion on the tectonic division of the Philippine Sea Plate

    Institute of Scientific and Technical Information of China (English)

    吴时国; 范建柯; 董冬冬

    2013-01-01

    菲律宾海板块是毗邻中国大陆的一个独特的小型板块.除南端表现十分复杂外,它的构造边界多以海沟为界,比较清楚,然而次级大地构造单元划分则比较复杂.本文根据近年来的研究成果,按照块体构造理论注重统一的地球物理场、相似的地壳结构、有机的成因联系等3个基本原则,将菲律宾海板块划分为3个具有不同构造演化特征的单元,即西菲律宾海块体、四国—帕里西维拉块体和伊豆—博宁—马里亚纳块体.西菲律宾海块体包括两部分:一个是西菲律宾海盆,始新世以来受太平洋板块和印澳板块近南北向的相对俯冲作用影响,并顺时针旋转形成了现今的构造样式,于30 Ma左右停止扩张.另一个包括大东盆岭、花东盆地、帕劳海盆和吕宋岛弧蛇绿岩等洋壳在内的白垩纪洋盆.根据形成年代和形成时的扩张方向可将四国—帕里西维拉块体分为两部分:四国海盆和帕里西维拉海盆,两者以索夫干断裂为界.伊豆—博宁—马里亚纳块体沿博宁高原南缘分为南北两部分,两者表现出不同的地质特征.%Philippine Sea Plate(PSP) is a unique minor plate close to China mainland.Except for the complicated southern part,the tectonic boundaries of the PSP are clear,most of which consist of trenches.However,it is hard to divide the plate into the secondary even three-level units.Based on the research in the recent years and referring to block tectonic theory with the principals of unitary geophysical field,similar crustal structure and organic genesis,the PSP is partitioned into three units with different evolutionary history,i.e.West Philippine Sea Block (WPSB),Shikoku-Parece Vela Block (SPB)and Izu-Bonin-Mariana Block (IBMB).The WPSB consists of two major parts,Cenozoic oceanic basin (west Philippine Basin)which was opened between two opposed subduction zones,rotated clockwise to the present place and culminated at ca.30 Ma

  6. A methodology for research on international cooperation on marine environment protection: application of the Baltic Sea practices to the northern seas

    Directory of Open Access Journals (Sweden)

    Kharlampyeva N. K.

    2011-01-01

    Full Text Available This article is dedicated to the methodology for the study of international cooperation on marine environment protection. The author suggests applying the practices of marine environment protection in the Baltic Sea to the northern seas as well as examining earlier projects for the effective implementation of interdisciplinary initiatives bringing together international law, international relations and world politics.

  7. A methodology for research on international cooperation on marine environment protection: application of the Baltic Sea practices to the northern seas

    Directory of Open Access Journals (Sweden)

    Kharlampyeva Nadezhda

    2011-03-01

    Full Text Available This article is dedicated to the methodology for the study of international cooperation on marine environment protection. The author suggests applying the practices of marine environment protection in the Baltic Sea to the northern seas as well as examining earlier projects for the effective implementation of interdisciplinary initiatives bringing together international law, international relations and world politics.

  8. The crustal structure of Egypt and the northern Red Sea region

    Science.gov (United States)

    Hosny, Ahmed; Nyblade, Andrew

    2016-09-01

    P-wave receiver functions from 26 stations in the Egyptian National Seismic Network (ENSN) have been modeled using the H-k stacking method and in a joint inversion method with Rayleigh wave group velocities to investigate crustal structure across Egypt and the northern Red Sea region. The new estimates of crustal structure, when combined with previous results, show that along the rifted margins of the Red Sea, Gulf of Suez and Gulf of Aqaba crustal thickness ranges from 25 to 30 km, the average crustal Vp/Vs ratio is 1.77, and the average crustal shear-wave velocity is 3.6 km/s. Beneath northern and central Egypt, including the Sinai Peninsula, crustal thickness ranges from 32 to 38 km, the average crustal Vp/Vs ratio is 1.79, and the average crustal shear-wave velocity is 3.5 km/s. Beneath southern Egypt, crustal thickness ranges from 35 to 40 km, the average crustal Vp/Vs ratio is 1.76, and the average crustal shear-wave velocity is 3.7 km/s. In southern Egypt, the crust is also characterized by a 10-20 km thick mafic lower crust. These findings indicate that crust along the rifted margins of the northern Red Sea, and Gulfs of Suez and Aqaba have been thinned by about 5 to 10 km. The thick mafic lower crust in southern Egypt can be attributed to suturing during the Neoproterozoic collision of east Gondwana against the Sahara metacraton. Overall, the structure of the crust in Egypt away from the northern Red Sea region is similar to the structure of Precambrian crust in many other parts of Africa.

  9. Tidal influence on suspended sediment distribution and dispersal in the northern Andaman Sea and Gulf of Martaban

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Rao, P.S.; Rao, K.H.; Thwin, S.; Rao, N.S.; Raiker, V.

    Surface and water column profiles of suspended matter collected during April-May 2002, and satellite images were used to study factors influencing suspended sediment concentrations (SSCs) and dispersal in the northern Andaman Sea and Gulf...

  10. Sea Cucumber Fishery and Trade in Sta. Cruz, Davao Del Sur, Philippines: Supply Chains and Cost-Benefit Analyses

    Directory of Open Access Journals (Sweden)

    Vlademir A. Shuck

    2013-11-01

    Full Text Available In the country, sea cucumbers are exploited almost exclusively for export. It is harvested in three ways; commercial fishing, artisanal fishing and gleaning. These methods provide disproportionate economic benefits to these players in the supply chain. In this study, sea ranching, a new culture system for sea cucumber was analyzed in terms of its economic and commercial viability. Under the sea ranching system Holothuriascabra(sandfish is the species being raised mainly due to its high economic value. Under the traditional method, labor comprises the largest share in the total cost, while the cost of juvenile and labor (monitoring cost accounts to almost 87% in the sea ranching system. Based on the results of the study, selling dried sandfish would gain positive net profit, while selling wet sandfish will incur a net loss. A significant difference in income was also observed between fishers who rely on traditional method and those who will adopt the new system. Sea ranching system is a very promising method that is expected to be beneficial both to the community and the environment. However, high capital requirement, uninformed community and the lack of support from the government and concerned agencies remains to be a big challenge

  11. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering Sea and Chukchi Sea

    Science.gov (United States)

    Sasaki, H.; Matsuno, K.; Fujiwara, A.; Onuka, M.; Yamaguchi, A.; Ueno, H.; Watanuki, Y.; Kikuchi, T.

    2015-11-01

    The advection of warm Pacific water and the reduction of sea-ice extent in the western Arctic Ocean may influence the abundance and distribution of copepods, i.e., a key component in food webs. To understand the factors affecting abundance of copepods in the northern Bering Sea and Chukchi Sea, we constructed habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods, separately, using generalized additive models. Copepods were sampled by NORPAC net. Vertical profiles of density, temperature and salinity in the seawater were measured using CTD, and concentration of chlorophyll a in seawater was measured with a fluorometer. The timing of sea-ice retreat was determined using the satellite image. To quantify the structure of water masses, the magnitude of pycnocline and averaged density, temperature and salinity in upper and bottom layers were scored along three axes using principal component analysis (PCA). The structures of water masses indexed by the scores of PCAs were selected as explanatory variables in the best models. Large Arctic copepods were abundant in the water mass with high salinity water in bottom layer or with cold/low salinity water in upper layer and cold/high salinity water in bottom layer, and small Arctic copepods were abundant in the water mass with warm/saline water in upper layer and cold/high salinity water in bottom layers, while Pacific copepods were abundant in the water mass with warm/saline in upper layer and cold/high salinity water in bottom layer. All copepod groups were abundant in areas with deeper depth. Although chlorophyll a in upper and bottom layers were selected as explanatory variables in the best models, apparent trends were not observed. All copepod groups were abundant where the sea-ice retreated at earlier timing. Our study might indicate potential positive effects of the reduction of sea-ice extent on the distribution of all groups of copepods in the Arctic Ocean.

  12. Mean Climatic Characteristics in High Northern Latitudes in an Ocean-Sea Ice-Atmosphere Coupled Model

    Institute of Scientific and Technical Information of China (English)

    刘喜迎; 张学洪; 俞永强; 宇如聪

    2004-01-01

    Emphasizing the model's ability in mean climate reproduction in high northern latitudes, results from an ocean-sea ice-atmosphere coupled model are analyzed. It is shown that the coupled model can simulate the main characteristics of annual mean global sea surface temperature and sea level pressure well, but the extent of ice coverage produced in the Southern Hemisphere is not large enough. The main distribution characteristics of simulated sea level pressure and temperature at 850 hPa in high northern latitudes agree well with their counterparts in the NCEP reanalysis dataset, and the model can reproduce the Arctic Oscillation (AO) mode successfully. The simulated seasonal variation of sea ice in the Northern Hemisphere is rational and its main distribution features in winter agree well with those from observations.But the ice concentration in the sea ice edge area close to the Eurasian continent in the inner Arctic Ocean is much larger than the observation. There are significant interannual variation signals in the simulated sea ice concentration in winter in high northern latitudes and the most significant area lies in the Greenland Sea, followed by the Barents Sea. All of these features agree well with the results from observations.

  13. Deep water bottom current deposition in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There are some active bottom currents on the northern continental slope of the South China Sea (SCS). Reflection seismic profiles show that the bottom current channels occur in the water depth range of 1000 to 2700 m,extending from the NE to the SW,leading to accumulation of discontinuous drifts with higher sedimentation rates on the eastern side of the channel. The stacking pattern of the layers sug-gests that these drifts propagated southwestward,following the direction of the bottom currents. One sedimentary drift to the southeast of the Dongsha Islands has the highest sedimentation rate of 97cm/ka in the last 12 ka. The sedimentary characteristics of the sediment layers indicate that these bottom currents are most likley caused by the water movement of a branch of the West Pacific Ocean Current,which enters the northern SCS via the Bashi Strait. Once formed,the bottom currents trans-port sediments along the northern slope of SCS southwestward and finally disappear into the central basin of the SCS. Due to the bottom current activity,the deep-sea sedimentary process in the northern SCS is complex.

  14. Sea Ice Variability in the Northern North Atlantic during the Last 14 Kyr BP

    Science.gov (United States)

    Cabedo-Sanz, P.; Belt, S. T.

    2014-12-01

    Sea ice plays an important role on the Earth's climate system by controlling fluxes of heat and moisture across the ocean-atmosphere interface and changes in the Earth's albedo, as well as oceanic circulation processes (e.g. the thermohaline circulation). Thus, reconstruction of Arctic sea ice is necessary to understand past sea ice variability and help improve the accuracy of model-based estimates of future changes in climate. Recently, the presence of the sea ice diatom biomarker IP25in Arctic marine sediments has been used as a proxy for past spring sea ice occurrence and as an indicator of wider palaeoenvironmental conditions for different regions of the Arctic over various timescales (e.g. Belt and Müller, 2013). Here, we present and compare new and existing biomarker data from different sediment cores along a S-N transect on the Norwegian - Svalvard continental margin from ca. 69 ºN to 78.5 ºN, northern North Atlantic. The presence and abundances of the sea ice biomarker IP25, a related HBI Diene and various sterols (e.g. brassicasterol, 24-methylenecholesterol) were used to infer past variations of sea ice/open-water conditions in the study area during the last 14 kyr BP. In addition, a comparison with other commonly used proxies for reconstructing different palaeoenvironmental conditions (e.g. planktic and benthic foraminiferal fauna, SST, IRD) was used to enable a more comprehensive reconstruction of climatic variations. References Belt, S.T., Müller, J., 2013. The Arctic sea ice biomarker IP25: a review of current understanding, recommendations for future research and applications in palaeo sea ice reconstructions. Quaternary Science Reviews 79, 9-25.

  15. Characteristics of the Bab al Mandab-Northern Afar area of the southern Red Sea

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.B. (Univ. of South Carolina, Columbia (United States)); Sikander, A.H. (World Bank, Washington, DC (United States)); Abouzakhm, A.G.

    1991-08-01

    The southern Red Sea and adjacent Afar area represent an enigmatic portion of the Red Sea/Gulf of Aden basin system. Although the topographic rift shoulders of the Red Sea and Gulf of Aden can be traced through this elbow, and appear to suggest that a similar width for the zone of extension is maintained across the region, the character of the floor of the rift zone changes. The distinctive character of the southern Red Sea-Afar area results in part from a topographically elevated region, possibly associated with the Red Sea-Gulf of Aden-East African rift triple junction. In addition, however, seismic data from offshore Ethiopia suggests that the distinctive character is due a complex pattern of rifting. The central axial trough of the Red Sea decreases in depth to the south toward the strait of Bab al Mandab, suggesting that rifting is dying out southward. Farther to the west at the same latitude, a major but narrow half-graben can be seen on seismic in the Gulf of Zula, bounded to the east by a large west-dipping normal fault. This structure continues south into the Danakil Depression of the Afar area. Between these two en echelon rift trends, the Danakil Alps form a long-lived high. Seismic data from the southern Red Sea of Ethiopia show southward thinning and pinch-out of the Miocene syn-rift evaporite sequence onto the northern Danakil block. Thus, it appears that the Danakil block has largely escaped Red Sea extension and subsidence. Instead, it forms a large unextended terrain located between overlapping en echelon rift trends, and may represent an accommodation zone structure associated with offset in the rift axis of the southern Red Sea.

  16. Holocene Northern Hemisphere sea-ice distribution - proxy data reconstruction and modelling

    Science.gov (United States)

    Seidenkrantz, Marit-Solveig; de Vernal, Anne; Goosse, Hugues; Klein, François; Solignac, Sandrine; Van Nieuwenhove, Nicolas; Pearce, Christof; Caissie, Beth; Belt, Simon; Sha, Longbin; Cronin, Thomas M.; Stein, Rüdiger; Macias-Fauria, Marc; DeNinno, Lauren H.

    2016-04-01

    resolution, our data indicate that sea ice was present in the Arctic throughout the Holocene and that no longer periods of absence of sea ice occurred. Our proxy data interpretations have been used to constrain model output using data assimilation in the LOVECLIM model, focusing on the period 6±0.5 ka. This period of warmer than present summer conditions can help to understand the dynamics of the system in a warmer world. As expected, data assimilation leads to an overall better agreement with the reconstructions, mainly because of changes in the simulated wind patterns. Overall, the model simulation suggests that during the Holocene Thermal Maximum sea ice distribution was controlled by a strong positive Northern Annular Mode.

  17. Water circulation and recharge pathways of coastal lakes along the southern Baltic Sea in northern Poland

    Directory of Open Access Journals (Sweden)

    Cieśliński Roman

    2016-12-01

    Full Text Available The purpose of this paper is to describe water circulation patterns for selected lakes found along the Baltic coast in northern Poland and to determine primary recharge mechanisms or pathways that produce an influx or loss of lake water. A secondary purpose of the paper is to determine the magnitude of recharge for each studied source of water – river water influx, surface runoff from direct catchments, forced influx from polders surrounding lakes, and periodic marine water intrusions from the nearby Baltic Sea. It is also important to determine the magnitude of water outflow from lakes to the sea via existing linkages as well as to compare horizontal influx and outflow data. The study area consisted of five lakes located along the Baltic Sea in northern Poland: Łebsko, Gardno, Bukowo, Kopań, Resko Przymorskie. The main driving force of the studied lakes are large rivers that drain lake catchment areas and periodic brackish water intrusions by the Baltic Sea.

  18. Numerical Simulation of Atmosphere-Ocean-Sea Ice Interaction During Interannual Cycle in High Northern Latitudes

    Institute of Scientific and Technical Information of China (English)

    LIU Xiying; LIU Hailong; LI Wei; ZHANG Xuehong; YU Rucong; YU Yongqiang

    2008-01-01

    The interannual atmosphere-ocean-sea ice interaction (AOSI) in high northern latitudes is studied with a global atmosphere-ocean-sea ice coupled model system, in which the model components of atmosphere and land surface are from China National Climate Center and that of ocean and sea ice are from LASG,Institute of Atmospheric Physics, Chinese Academy of Sciences. A daily flux anomaly correction scheme is employed to couple the atmosphere model and the ocean model with the effect of inhomogenity of sea ice in high latitudes is considered. The coupled model system has been run for 50 yr and the results of the last 30 years are analyzed. After the sea level pressure (SLP), surface air temperature (SAT), sea surface temperature (SST), sea ice concentration (SIC), and sea surface sensible heat flux (SHF) are filtered with adigital filter firstly, their normalized anomalies are used to perform the decomposition of combined complex empirical orthogonal function (CCEOF) and then they are reconstructed with the leading mode. The atmosphere-ocean-sea ice interactions in high northern latitudes during a periodical cycle (approximately4 yr) are analyzed. It is shown that: (1) When the North Atlantic Oscillation (NAO) is in its positive phase, the southerly anomaly appears in the Greenland Sea, SAT increases, the sea loses less SHF, SST increases and SIC decreases accordingly; when the NAO is in its negative phase, the northerly anomaly appears in the Greenland Sea, SAT decreases, the sea loses more SHF, SST decreases and SIC increases accordingly. There are similar features in the Barents Sea, but the phase of evolution in the Barents Sea is different from that in the Greenland Sea. (2) For an average of multi-years, there is a cold center in the inner part of the Arctic Ocean near the North Pole. When there is an anomaly of low pressure, which is closer to the Pacific Ocean, in the inner part of the Arctic Ocean, anomalies of warm advection appear in the region near the

  19. APPROACH TO THE REGIONALIZATION OF AGRICULTURAL—PASTURALIZATION AROUND CHANGSHAN ISLANDS IN NORTHERN YELLOW SEA

    Institute of Scientific and Technical Information of China (English)

    ZAHNGYao-guang; DONGLi-jing; 等

    2002-01-01

    Based on the data of resources,environment and foundation of production,applying principal compo-nents-clustering quantitative analysis,this article divides the maritime space of Changshan Islands into three regions of agricultural-pasturalization,providing a scientific basis for the rational distribution of marine cultivation.The three re-gions are as follows:1)The region of an agricultural-pasturalization in the northern part of maritime space.It includes Da Wangjia and Shicheng islans.The main production is cultivation of prawn and mollusks in sea beach,float raft culture of mussel in shallow sea and scallop ,and breeding of sea cucumber in submarine.2)The region of agricultur-al-pasturalization in the middle western part of maritime space.It includes Da Changshan and Guanglu islands and west-ern part of Xiao Chengshan Island.The man production is folat raft culture of mussel and scallop in shallow sea,and breed-ing of sea cucumber in submarine.3)The region of agricultural-pasturlization of the southeastem part of maritime space.It includes the eastern part of Xiao Chan Island,Haiyang and Zhangzi islands.The main production is breeding of abalone,sea cucumber,algaes and fish.

  20. APPROACH TO THE REGIONALIZATION OF AGRICULTURAL PASTURALIZATION AROUND CHANGSHAN ISLANDS IN NORTHERN YELLOW SEA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the data of resources, environment and foundation of production, applying principal components-clustering quantitative analysis, this article divides the maritime space of Changshan Islands into three regions ofagricultural-pasturalization, providing a scientific basis for the rational distribution of marine cultivation. The three regions are as follows: 1 )The region of an agricultural-pasturalization in the northern part of maritime space. It includes DaWangjia and Shicheng islands. The main production is cultivation of prawn and molluscs in sea beach, float raft cultureof mussel in shallow sea and scallop, and breeding of sea cucumber in submarine. 2) The region of agricultural-pasturalization in the middle western part of maritime space. It includes Da Changshan and Guanglu islands, and westem part of Xiao Chengshan Island. The main production is float raft culture of mussel and scallop in shallow sea, and breeding of sea cucumber in submarine. 3)The region of agricultural-pasturalization of the southeastern part of maritime space.It includes the eastern part of Xiao ChangShan Island, Haiyang and Zhangzi islands. The main production is breeding ofabalone, sea cucumber, algaes and fish.

  1. First record of Ostreopsis cfr. ovata on macroalgae in the Northern Adriatic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Monti, Marina [Department of Biological Oceanography, National Institute of Oceanography and Applied Geophysics, Via Auguste Piccard 54, 34010 Trieste (Italy)]. E-mail: mmonti@inogs.it; Minocci, Marco [Department of Biological Oceanography, National Institute of Oceanography and Applied Geophysics, Via Auguste Piccard 54, 34010 Trieste (Italy); Beran, Alfred [Department of Biological Oceanography, National Institute of Oceanography and Applied Geophysics, Via Auguste Piccard 54, 34010 Trieste (Italy); Ivesa, Ljiljana [Ruder Boskovic Institute, Center for Marine Research, G. Paliaga 5, 52210 Rovinj (Croatia)

    2007-05-15

    Ostreopsis ovata is an epiphytic potentially toxic dinoflagellate. It has a world-wide distribution, normally associated with other epiphytic or benthic dinoflagellates. In tropical seas O. ovata is often associated with the genera Gambierdiscus, Coolia and Prorocentrum, causing cinguatera fish poisoning. Recently, Ostreopsis spp. blooms in the Tyrrhenian and southern Adriatic Sea have been related to human health problems, such as breathing and skin irritation. Here we report the first record of Ostreopsis cfr. ovata in the Northern Adriatic Sea. O. cfr. ovata was isolated from macroalgae in two areas, the Gulf of Trieste (Italy) and close to Rovinj (Croatia). The microalga was identified by scanning electron microscopy and by fluorescence light microscopy. Size range and thecal pore structure were similar to those described for O. cfr. ovata in previous studies. Ostreopsis cfr. ovata was present on all the macroalgae collected, particularly browns and reds. The microalgal association on macroalgae was mostly composed of Ostreopsis sp., Coolia monotis and Coscinodiscus sp.

  2. Pollen record of the last 280 ka from deep sea sediments of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    SUN; Xiangjun

    2001-01-01

    [1]Wang, P., West Pacific in glacial cycles: Seasonality in marginal sea and variability of Warm Pool, Science in China, Ser.D, 1998, 41 (1): 35.[2]Jian, Z., Li, B., Pflaumann, U. et al., Late Holocene cooling event in the West Pacific, Science in China, Ser. D, 1996,39(5): 543.[3]Jian, Z., Chen, M., Lin, H. et al., Stepwise paleoceanographic changes during the last deglaciation in the southern South China Sea: Records of stable isotope and microfossils, Science in China, Ser. D, 1998, 41(2): 187.[4]Sun, X., Li, X., A pollen record of the last 37 ka in deep sea core 17940 from the northern slope of the South China Sea,Marine Geology, 1999, 156: 224-227.[5]Sun, X, Li, X., Luo, Y. et al., The vegetation and climate at the last glaciation on the emerged continental shelf of the South China Sea, Palaeogeogr. Palaeoclimatol. Palaeoecol., 2000, 160:301-316.[6]Department of Tectonics, Institute of Oceanography, Chinese Academy of Sciences, Geological Tectonics of the South China Sea and Spreading of the Continental Margin (in Chinese), Beijing: Science Press, 1988, 339-379.[7]Zhao Huanting, Zhang Qiaomin, Song Chaojing et al., Geomorphology and environment of the South China Sea islands (in Chinese), Beijing: Science Press, 1999, 1-528.[8]Wang, P., Prell, W. L., Blum, P. et al., Proc, ODP, Init. Repts. 184, College Station TX (Ocean Drilling Program), 2000,1-77.[9]Florin, R., The distribution of conifer and taxad genera in time and space, Acta Horti Bergiani., 1963, 20 (4): 121-312.[10]Cooling, E. N. G., Pinus Mercusii Fast Growing Timber Tree of Lowland Tropics, Oxford: Dep. Forestry, Oxford, 1968.[11]Sun, X., Li, X., Beug, H. J., Pollen distribution in hemipelagic surface sediments of the South China Sea and its relation to modem vegetation distribution, Mar. Geol., 1999, 156:211226.[12]Sun Xiangjun, Song Changqing, Wang Fengyu, Pollen-climate response surface of selected taxa from northern China, Sci ence in China, Ser. D

  3. Biogeochemical cycling in the Bering Sea over the onset of major Northern Hemisphere Glaciation

    Science.gov (United States)

    Swann, George E. A.; Snelling, Andrea M.; Pike, Jennifer

    2016-09-01

    The Bering Sea is one of the most biologically productive regions in the marine system and plays a key role in regulating the flow of waters to the Arctic Ocean and into the subarctic North Pacific Ocean. Cores from Integrated Ocean Drilling Program (IODP) Expedition 323 to the Bering Sea provide the first opportunity to obtain reconstructions from the region that extend back to the Pliocene. Previous research at Bowers Ridge, south Bering Sea, has revealed stable levels of siliceous productivity over the onset of major Northern Hemisphere Glaciation (NHG) (circa 2.85-2.73 Ma). However, diatom silica isotope records of oxygen (δ18Odiatom) and silicon (δ30Sidiatom) presented here demonstrate that this interval was associated with a progressive increase in the supply of silicic acid to the region, superimposed on shift to a more dynamic environment characterized by colder temperatures and increased sea ice. This concluded at 2.58 Ma with a sharp increase in diatom productivity, further increases in photic zone nutrient availability and a permanent shift to colder sea surface conditions. These transitions are suggested to reflect a gradually more intense nutrient leakage from the subarctic northwest Pacific Ocean, with increases in productivity further aided by increased sea ice- and wind-driven mixing in the Bering Sea. In suggesting a linkage in biogeochemical cycling between the south Bering Sea and subarctic Northwest Pacific Ocean, mainly via the Kamchatka Strait, this work highlights the need to consider the interconnectivity of these two systems when future reconstructions are carried out in the region.

  4. Phylogeography of the mottled spinefoot Siganus fuscescens: Pleistocene divergence and limited genetic connectivity across the Philippine archipelago.

    Science.gov (United States)

    Ravago-Gotanco, R G; Juinio-Meñez, M A

    2010-10-01

    Historical isolation during Pleistocene low sea level periods is thought to have contributed to divergence among marine basin populations across the Coral Triangle. In the Philippine archipelago, populations in the South China Sea, Sulu Sea-inland seas, and Philippine Sea-Celebes Sea basins might have been partially isolated. Meanwhile, present-day broadscale oceanographic circulation patterns suggest connectivity between these basins. To evaluate hypotheses regarding the influence of historical and contemporary factors on genetic structure, phylogeographic patterns based on mitochondrial control region sequences for a reef-associated fish, Siganus fuscescens, were analysed. Three distinct lineages were recovered. One lineage was identified as the morphologically similar species Siganus canaliculatus, while two lineages are monophyletic with S. fuscescens. Clade divergence and demographic expansion in S. fuscescens occurred during the Pleistocene. A strong signal of latitudinal structure was detected (Φ(CT)  = 0.188), driven by marked differences in clade distribution: one clade is widely distributed (clade A), while a second clade (clade B) has a restricted northern distribution. Regional structure of clade A is consistent with the basin isolation hypothesis (Φ(CT)  = 0.040) and suggests isolation of the South China Sea (Φ(CT)  = 0.091). Fine-scale structure was observed in the South China Sea and south Philippine Sea, while Sulu Sea and inland seas were unstructured. Genetic structure across multiple spatial scales (archipelagic, regional, and fine-scale within basins) suggests the influence of vicariant barriers and contemporary limits to gene flow in S. fuscescens that may be influenced by oceanographic circulation, geographical distance between available habitats, and latitudinal temperature differences.

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; LUAN Xiwu

    2013-01-01

    Submarine landslides occur frequently on most continental margins.They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations.In this paper,submarine slope stability is evaluated using a 2D limit equilibrium method.Considerations of slope,sediment,and triggering force on the factor of safety (FOS) were calculated in drained and undrained (φ=0) cases.Results show that submarine slopes are stable when the slope is <16° under static conditions and without a weak interlayer.With a weak interlayer,slopes are stable at <18° in the drained case and at <9° in the undrained case.Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure.The slope became unstable at >13° with earthquake peak ground acceleration (PGA) of 0.5 g;whereas with a weak layer,a PGA of 0.2 g could trigger instability at slopes > 10°,and >3 ° for PGA of 0.5 g.The northern slope of the South China Sea is geomorphologically stable under static conditions.However,because of the possibility of high PGA at the eastern margin of the South China Sea,submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope.Therefore,submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake,the most important factor for triggering submarine slides on the northern slope of the South China Sea.Considering the distribution of PGA,we consider the northern slope of the South China Sea to be stable,excluding the Taiwan Bank slope,which is tectonically active.

  6. Metals in Blood and Eggs of Green Sea Turtles (Chelonia mydas) from Nesting Colonies of the Northern Coast of the Sea of Oman.

    Science.gov (United States)

    Sinaei, Mahmood; Bolouki, Mehdi

    2017-06-19

    The green sea turtle (Chelonia mydas) has been a species of global concern for decades. In this study, heavy metals (mercury: Hg; Cadmium: Cd; Lead: Pb; Copper: Cu; and Zinc: Zn) were measured in blood and three egg fraction of green sea turtles nesting on the northern coast of Sea of Oman. Heavy metals concentrations in blood, yolk, albumen, and egg shell ranged between 0.16-36.78, 0.006-33.88, 0.003-4.02, and 0.002-6.85 μg/g (ww), respectively. According to the results, all heavy metals found in blood samples (n = 12) also were detected in the various parts of the eggs (n = 48). Moreover, there were no significant differences between concentrations of heavy metals in different clutches laid in a nesting season. However, Pb concentrations in blood samples significantly increased in later clutches (p sea turtles on the northern coast of Sea of Oman. Results of this study suggest that heavy metals could be one of the factors influencing reductions in fertilization and hatching success. Results also indicate that green sea turtle on the northern coast of Sea of Oman have high capacity in rapid response and detoxification of heavy metals and/or from the low exposure levels of these turtles to the heavy metals. Further research is required concerning the effects of heavy metals on green sea turtles, especially on their possible influence of fetal development of turtles.

  7. Cenozoic magmatism in the northern continental margin of the South China Sea: evidence from seismic profiles

    Science.gov (United States)

    Zhang, Qiao; Wu, Shiguo; Dong, Dongdong

    2016-06-01

    Igneous rocks in the northern margin of the South China Sea (SCS) have been identified via high resolution multi-channel seismic data in addition to other geophysical and drilling well data. This study identified intrusive and extrusive structures including seamounts and buried volcanoes, and their seismic characteristics. Intrusive features consist of piercement and implicit-piercement type structures, indicating different energy input associated with diapir formation. Extrusive structures are divided into flat-topped and conical-topped seamounts. Three main criteria (the overlying strata, the contact relationship and sills) were used to distinguish between intrusive rocks and buried volcanos. Three criteria are also used to estimate the timing of igneous rock formation: the contact relationship, the overlying sedimentary thickness and seismic reflection characteristics. These criteria are applied to recognize and distinguish between three periods of Cenozoic magmatism in the northern margin of the SCS: before seafloor spreading (Paleocene and Eocene), during seafloor spreading (Early Oligocene-Mid Miocene) and after cessation of seafloor spreading (Mid Miocene-Recent). Among them, greater attention is given to the extensive magmatism since 5.5 Ma, which is present throughout nearly all of the study area, making it a significant event in the SCS. Almost all of the Cenozoic igneous rocks were located below the 1500 m bathymetric contour. In contrast with the wide distribution of igneous rocks in the volcanic rifted margin, igneous rocks in the syn-rift stage of the northern margin of the SCS are extremely sporadic, and they could only be found in the southern Pearl River Mouth basin and NW sub-sea basin. The ocean-continent transition of the northern SCS exhibits high-angle listric faults, concentrated on the seaward side of the magmatic zone, and a sharply decreased crust, with little influence from a mantle plume. These observations provide further evidence to

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

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

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

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

    Science.gov (United States)

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

    2011-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

    ZHAI Hongchang; NING Xiuren; TANG Xuexi; HAO Qiang; LE Fengfeng; QIAO Jing

    2011-01-01

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

  11. Carbon dioxide in northern high latitude oceans: Anthropogenic increase and air-sea flux variability

    Energy Technology Data Exchange (ETDEWEB)

    Omar, Abdirahman M.

    2003-07-01

    The aim of this thesis is to further our knowledge of carbon dioxide in the northern high latitude oceans (northern North Atlantic, Barents Sea, and Arctic Ocean) by studying the anthropogenic change in the oceanic CO2, the inter-annual variability of the air-sea CO2 flux, and the relationship between this variability and changes in other oceanic processes. An introductory chapter and four papers are presented. Descriptions of the seawater carbonate system parameters, air-sea exchange of CO2, and related processes are given in the introduction chapter. The anthropogenic increase in partial pressure of CO2 (pCO2) in the surface water of the Barents Sea is evaluated in paper I. The effect of alternations of the Barents Sea climate between cold and warm modes on the annual cycles of seawater fugacity and air-sea flux of CO2 is investigated in paper II. Oceanic uptake of atmospheric CO2 associated with the seasonal formation of sea ice in Storfjorden and the implication for the entire Arctic Ocean is studied in paper III. An assessment of the variations of the air-sea flux of CO2 in the northern North Atlantic for 20 winters (1981-2001) is carried out in paper IV. PCO2 in the surface water of the Barents Sea is shown to have increased parallel with the atmospheric pCO2 between 1967 and 2000-2001 (paper I). This was determined by comparing seawater pCO2 from 1967 with that from 2000-2001. The former was estimated from surface seawater temperature (SST) while the latter was computed from data of total dissolved inorganic carbon and alkalinity. A procedure which accounts for the natural variability was applied and the difference between seawater pC02 of 1967 and that of 2000-2001 is attributed to the uptake of excess CO2. In the Atlantic sector of the Barents Sea, the surface seawater fugacity of CO2 (fCO s''w) is shown to be lower than the atmospheric fCO2 throughout the year, implying that the area is an annual sink of atmospheric CO2 (paper II). Additionally

  12. The Effects of Changing Sea Ice on Marine Mammals and Their Hunters in Northern Alaska

    Science.gov (United States)

    Huntington, H.; Quakenbush, L.; Nelson, M.

    2015-12-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information and insight relevant to ecological understanding, conservation action, and the regulation of human activity. We interviewed hunters in villages from northern Bering Sea to the Beaufort Sea, focusing on bowhead whales, walrus, and ice seals. Hunters reported extensive changes in sea ice, with resulting effects on the timing of marine mammal migrations, the distribution and behavior of the animals, and the efficacy of certain hunting methods, for example the difficulty of finding ice thick enough to support a bowhead whale for butchering. At the same time, hunters acknowledged impacts and potential impacts from changing technology such as more powerful outboard engines and from industrial activity such as shipping and oil and gas development. Hunters have been able to adapt to some changes, for example by hunting bowhead whales in fall as well as spring on St. Lawrence Island, or by focusing their hunt in a shorter period in Nuiqsut to accommodate work schedules and worse weather. Other changes, such as reduced availability of ice seals due to rapid retreat of pack ice after spring break-up, continue to defy easy responses. Continued environmental changes, increased disturbance from human activity, and the introduction of new regulations for hunting may further challenge the ability of hunters to provide food as they have done to date, though innovation and flexibility may also provide new sources of adaptation.

  13. Recent progress of deep seismic experiments and studies of crustal structure in northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The South China Sea (SCS) is one of the largest marginal seas in the western Pacific. Its northern part has the features of a passive continental margin. The studies of deep crustal structure in this area are very important for understanding the tectonic nature, evolution history, basin formation of the northern margin, and the origin of the SCS. In the past decades, the deep seismic experiments of crustal studies in the northern SCS have gone through three stages, namely the sonobuoy, two-ship Expanding Spread Profile (ESP), and Ocean Bottom Hydrophone/Seismometer (OBH/OBS). Along the continental slope, the sonobuoy experiments provided useful information about the velocity structure of the upper crust, while the ESP data recorded for the first time the seismic signals from deep crustal structure and Moho interface. And the OBH/OBS profiles revealed the crustal structure in much greater detail. This paper first gives a brief historical review of these deep seismic experiments and studies, then a summary of the latest progress and important research results. The remaining problems and suggestions for further research work are presented as conclusive remarks.

  14. An abrupt cooling event early in the last interglacial in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The high-resolution quantitative analysis of the planktonic foraminifera and the δ18O records of the section between 96.49-137.6 mcd at ODP Site 1144 on the continental slope ot northern South China Sea reveals an abrupt cooling event of sea surface temperature (SST) dur ing the last interglacial (MIS 5.5, i.e. 5e). The dropping range of the winter SST may come to 7.5℃corresponding to 1.2‰ of the δ18O value of sea surface water. This event is comparable with those discovered in the west Europe and the northern Atlantic Ocean, but expressed in a more intensive way. It is inferred that this event may have been induced by middle- to Iow-latitude processes rather than by polar ice sheet change. Since the Kuroshio-index species Pulleniatina obliquilocu lata displayed the most distinct change at the event, it may also be related to the paleocean ographic change of the Iow-latitude area in the western Pacific Ocean. This event can be consid ered as one of "Younger Dryas-style coolings" and is indicative of climate variability of the last in terglacial stage.

  15. Sediment flux and source in northern Yellow Sea by 210Pb technique

    Institute of Scientific and Technical Information of China (English)

    LI Fengye; LI Xuegang; SONG Jinming; WANG Guizhi; CHENG Peng; GAO Shu

    2006-01-01

    Sedimentation of fine-grained deposits on coastal zones and continental shelves are important because of the association with chemical pollutants, and the implication to the impact on biological processes, the stratigraphic correlations, and changes in sedimentary environments. The Yellow Sea continental shelf receives large quantities of sediment from the Huanghe (Yellow) River. Unfortunately, little attention has been yet paid to the sedimentation on the shallow shelf and its features, and the vertical sediment flux in the area is poorly understood. In this study, nine cores were collected in northern Yellow Sea by the R/V Science 1 in September, 1998 and 1999 to examine the sedimentation rate, sediment flux and the provenance with 210Pb analysis. The 210Pb activity profiles showed that the vertical sediment flux ranged from 0.06 to 1.18 g/cm2·a in the region. In central part of the area, there was a patch of fine-grained mud, with the flux below 0.33 g/cm2·a. Most profiles were featured in two-segment model. Differences in the profiles reflected spatial and temporal variations in hydrodynamic and sedimentary processes. In order to determine the provenance and sedimentary setting in the area, the geochemistry of Ca, Fe, Sr, Cu, Ti and Rb in 11 surficial sediment samples were studied, which showed that in the central northern Yellow Sea, the mud deposit was from multi-source but mainly from the Huanghe River.

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

    Science.gov (United States)

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

    2009-06-01

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

  17. Bacterial diversity of polluted surface sediments in the northern Adriatic Sea.

    Science.gov (United States)

    Korlević, Marino; Zucko, Jurica; Dragić, Mirjana Najdek; Blažina, Maria; Pustijanac, Emina; Zeljko, Tanja Vojvoda; Gacesa, Ranko; Baranasic, Damir; Starcevic, Antonio; Diminic, Janko; Long, Paul F; Cullum, John; Hranueli, Daslav; Orlić, Sandi

    2015-05-01

    Samples were collected from sea sediments at seven sites in the northern Adriatic Sea that included six sites next to industrial complexes and one from a tourist site (recreational beach). The samples were assayed for alkanes and polycyclic aromatic hydrocarbons. The composition of the hydrocarbon samples suggested that industrial pollution was present in most cases. A sample from one site was also grown aerobically under crude oil enrichment in order to evaluate the response of indigenous bacterial populations to crude oil exposure. Analysis of 16S rRNA gene sequences showed varying microbial biodiversity depending on the level of pollution--ranging from low (200 detected genera) to high (1000+ genera) biodiversity, with lowest biodiversity observed in polluted samples. This indicated that there was considerable biodiversity in all sediment samples but it was severely restricted after exposure to crude oil selection pressure. Phylogenetic analysis of putative alkB genes showed high evolutionary diversity of the enzymes in the samples and suggested great potential for bioremediation and bioprospecting. The first systematic analysis of bacterial communities from sediments of the northern Adriatic Sea is presented, and it will provide a baseline assessment that may serve as a reference point for ecosystem changes and hydrocarbon degrading potential--a potential that could soon gain importance due to plans for oil exploitation in the area.

  18. Carbonate chemistry dynamics and biological processes along a river-sea gradient (Gulf of Trieste, northern Adriatic Sea)

    Science.gov (United States)

    Ingrosso, Gianmarco; Giani, Michele; Cibic, Tamara; Karuza, Ana; Kralj, Martina; Del Negro, Paola

    2016-03-01

    In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea). By combining synoptic measurements of the carbonate system with in situ determinations of the primary production (14C incorporation technique) and secondary prokaryotic carbon production (3H-leucine incorporation) along a river-sea gradient, we showed that the conservative mixing between river endmember and off-shore waters was the main driver of the dissolved inorganic carbon (DIC) distribution and seasonal variation. However, during spring and summer seasons also the influence of biological uptake and release of DIC was significant. In the surface water of June 2012, the spreading and persistence of nutrient-rich freshwater stimulated the primary production (3.21 μg C L- 1 h- 1) and net biological DIC decrease (- 100 μmol kg- 1), reducing the dissolved CO2 concentration and increasing the pHT. Below the pycnocline of August 2012, instead, an elevated bacterial carbon production rate (0.92 μg C L- 1 h- 1) was related with net DIC increase (92 μmol kg- 1), low dissolved oxygen concentration, and strong pHT reduction, suggesting the predominance of bacterial heterotrophic respiration over primary production. The flux of carbon dioxide estimated at the air-sea interface exerted a low influence on the seasonal variation of the carbonate system. A complex temporal and spatial dynamic of the air-sea CO2 exchange was also detected, due to the combined effects of seawater temperature, river discharge, and water circulation. On annual scale the system was a sink of atmospheric CO2. However, in summer and during elevated riverine discharges, the area close to the river's mouth acted as a source of carbon dioxide. Also the wind speed was crucial in controlling the air-sea CO2

  19. Locations of nonstructural hydrocarbon traps on the shelf of the northern Barents Sea

    Science.gov (United States)

    Kazanin, G. S.; Pavlov, S. P.; Tarasov, G. A.; Schlykova, V. V.; Matishov, G. G.

    2016-11-01

    This paper considers the results of summarized integrated geophysical investigations that were carried out from 2006 to 2012. The investigations included common depth point (CDP) seismic reflection survey, over water gravity survey, and differential hydromagnetic exploration with a total work scope of 30 000 linear kilometers. The deep structural tectonic plan, the structural and lithofacies features of the sedimentary cover section on the basic reflecting boundaries, and the features of the seismogeological complexes and seismic sections on a depth scale have been studied, and geological oil-and-gas zoning of the Northern Barents shelf has been made. Seventy-nine local anticlinal highs have been revealed, and the zones with potential nonstructural hydrocarbon traps have been determined. Due to the lack of huge anticlinal highs in the northern Barents Sea region, nonstructural traps are of interest in studying and replacing the mineral raw material base of Russia, as well as for arranging marine exploration.

  20. Some characteristics and evolution of the internal soliton in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the observational data of an internal soliton in the northern South China Sea (SCS) on June 14, 1998, the possible source of the internal soliton is analyzed, and some of its characteristic parameters such as phase speed, wave length, etc. are computed. Based on the analyses of the vertical modes of the internal wave, the characteristics of the wave-induced current during the propagation of the internal soliton are studied. A regularized long wave (RLW) equation numerical model considering effects of multi-fac- tors is employed, and the observed environmental parameters are used as the initial conditions to simulate the propagation and evolution of the internal soliton in the continental shelf of the northern SCS.

  1. Towards integrated assessment of the northern Adriatic Sea sediment budget using remote sensing

    Science.gov (United States)

    Taramelli, A.; Filipponi, F.; Valentini, E.; Zucca, F.; Gutierrez, O. Q.; Liberti, L.; Cordella, M.

    2014-12-01

    Understanding the factors influencing sediment fluxes is a key issue to interpret the evolution of coastal sedimentation under natural and human impact and relevant for the natural resources management. Despite river plumes represent one of the major gain in sedimentary budget of littoral cells, knowledge of factors influencing complex behavior of coastal plumes, like river discharge characteristics, wind stress and hydro-climatic variables, has not been yet fully investigated. Use of Earth Observation data allows the identification of spatial and temporal variations of suspended sediments related to river runoff, seafloor erosion, sediment transport and deposition processes. Objective of the study is to investigate sediment fluxes in northern Adriatic Sea by linking suspended sediment patterns of coastal plumes to hydrologic and climatic forcing regulating the sedimentary cell budget and geomorphological evolution in coastal systems and continental shelf waters. Analysis of Total Suspended Matter (TSM) product, derived from 2002-2012 MERIS time series, was done to map changes in spatial and temporal dimension of suspended sediments, focusing on turbid plume waters and intense wind stress conditions. From the generated multi temporal TSM maps, dispersal patterns of major freshwater runoff plumes in northern Adriatic Sea were evaluated through spatial variability of coastal plumes shape and extent. Additionally, sediment supply from river distributary mouths was estimated from TSM and correlated with river discharge rates, wind field and wave field through time. Spatial based methodology has been developed to identify events of wave-generated resuspension of sediments, which cause variation in water column turbidity, occurring during intense wind stress and extreme metocean conditions, especially in the winter period. The identified resuspension events were qualitatively described and compared with to hydro-climatic variables. The identification of spatial and

  2. The problem of the availability of nautical charts and publications on the Northern Sea Route

    Directory of Open Access Journals (Sweden)

    Pastusiak Tadeusz

    2015-03-01

    Full Text Available Statistical studies of marine accidents and unfortunate events in ice-covered areas in 1995–2004 and 2004–2011 showed a general lack of information from the area under the jurisdiction of the Russian Federation. The author’s research for the period 2004–2011 showed a large number of unfortunate events caused by lack of adequate provision of nautical charts, shortage of accurate position systems on board vessels as well as weak technical condition of these vessels. The author examined the problem of navigation safety on the Northern Sea Route in terms of availability of the official nautical charts and publications.

  3. Variability in growth rates of larval haddock in the northern North Sea

    DEFF Research Database (Denmark)

    Gallego, A.; Heath, M.R.; Basford, D.J.

    1999-01-01

    The large-scale distribution of haddock (Melanogrammus aeglefinus) larvae in the northern North Sea was mapped in a grid survey carried out in late April 1996. A drifting buoy was deployed in the centre of one of the areas of concentration of larvae located off the east coast of the Shetland Isles...... at age than those hatched earlier. Particle-tracking modelling suggested that differences in temperature history between cohorts, on their own or compounded by a potential interaction between temperature and the development of plankton production, may explain the higher growth rate of the larvae hatched...

  4. SOZOLOGICAL CHARACTERISTIC OF VEGETATION OF FORESTS AND SHRUBS OF THE NORTHERN BLACK SEA REGION

    Directory of Open Access Journals (Sweden)

    I. V. Solomakha

    2015-12-01

    Full Text Available As a result of sociological analysis found that in the vegetation cover of forests and shrubs in the Northern Black Sea found 88 view of rare and endangered plants. For 37 species, there are phytocoenotic table, the data on the other - are induced for that literary materials herbarium. They have a different distribution in the classes of the vegetation on the study territory: Pulsatillo-Pinetea sylvestris (13 species, Dactilydo glomeratae-Populetea tremulae (13, Festuco-Brometea (9, Rhamno-Prunetea (8, Nerio-Tamaricetea (7, Salicetea purpureae (5, Robinietea (3, Alnetea glutinosae (3, Franguletea (3. Some rare and endangered communities of the territory need to be included in the «Green Book of Ukraine». Key words: vegetation, syntaxonomy, forests, shrubs, sozological characteristic, Northen Black Sea region.

  5. Trace-Metal Enrichment and Pollution in Coastal Sediments in the Northern Tyrrhenian Sea, Italy.

    Science.gov (United States)

    Piazzolla, Daniele; Scanu, Sergio; Frattarelli, Francesco Manfredi; Mancini, Emanuele; Tiralongo, Francesco; Brundo, Maria Violetta; Tibullo, Daniele; Pecoraro, Roberta; Copat, Chiara; Ferrante, Margherita; Marcelli, Marco

    2015-11-01

    This study evaluated the distribution pattern and pollution of chromium, arsenic (As), manganese (Mn), nickel, lead, and copper in surface sediments along the northern Latium coast of the Tyrrhenian Sea in Italy. The enrichment factor, geoaccumulation index, and potential toxicity response index were used to evaluate the degree of contamination. These results show As and Mn contamination. The high enrichment and contamination levels of As and Mn are located in two hot spots. These elevations are due to naturally high levels of As and Mn in the Mignone River and the Marangone Stream as well as the intense human activity in the area including the largest energy production site in Europe (Torrevaldaliga Nord coal-fired power plant) and of one of the most important ports for cruise traffic in the Mediterranean Sea.

  6. Paleoceanographic evolution recorded in the northern South China Sea since 4 Ma

    Institute of Scientific and Technical Information of China (English)

    HUANG Baoqi; JIAN Zhimin; WANG Pinxian

    2005-01-01

    Upper water structure over the last 4 million years in the northern South China Sea (SCS) was reconstructed by sea surface temperature (SST) and primary productivity estimated by changes in the abundance of planktonic foraminifer, planktonic foraminifer transfer function, and the accumulation rate of benthic foraminifera. Results of SST and primary productivity show that SST gradually decreased since 4 Ma, but differential seasonal temperature and primary productivity increased in steps mainly at about 3.1, 2.7, 2.1, 1.6, 0.9 and 0.5 Ma. Comparison with tectonics and orbital variations indicates that phased rising of the Tibet since 3.6 Ma, closing of Panama and Indonesian seaways, and orbital changes were responsible for the changes of upper water structure in the SCS, respectively.

  7. Status and trends of sea otters in the northern Pacific Ocean

    Science.gov (United States)

    Bodkin, James L.; Estes, James A.; Jameson, Ronald J.; LaRoe, E.T.; Farris, G.S.; Puckett, C.E.; Doran, P.D.; Mac, M.J.

    1995-01-01

    About 250 years ago sea otters (Enhydra lutris) were distributed continuously from central Baja California, north and west along the Pacific Rim to Machatka Peninsula in Russia, and south along the Kuril Island to northern Japan (Kenyon 1969; Fig. 1a). Several hundred thousand sea otters may have occurred in the north Pacific region when commercial hunting began in the 18th century (Riedman and Estes 1990). At least two attributes of the sea otter have influenced humans, likely for as long as they have resided together along the coast of the north Pacific Ocean. First, sea otters rely on a dense fur, among the finest in the world, for insulation in the cold waters of the Pacific Ocean. The demand for sea otter fur led to their near extinction in the 19th century. The fur harvest, begun about 1740 and halted by international treaty in 1911, left surviving colonies, each likely numbering less than a few hundred animals, in California, south-central Alaska, and the Aleutian, Medney, and Kuril Islands (Fig. 1a). These individuals provided the nucleus for the recovery of the species. Today more than 100,000 sea otters occur throughout about 75% of their original range (fig. 1b). Immigration has resulted in near-complete occupation of the Aleutian and Kuril archipelagos and the Alaska peninsula. Successful translocations have resulted in viable populations in southeast Alaska, Washington, and British Columbia. Large amounts of unoccupied habitat remain along the coasts of Russia, Canada, the United States, and Mexico. The second potential source of conflict between sea otters and humans is that sea otters prey on and often limit some benthic invertebrate populations. Because some of these invertebrates are aso used by humans (Estes and VanBlaricom 1985), human perceptions about the effects of sea otter foraging on invertebrates sometimes differ. By limiting populations of herbivorous invertebrates (e.g., sea urchins [Echinoidea]) otters help maintain the integrity of

  8. Community structure and biodiversity of free-living marine nematodes in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoshou; XU Man; ZHANG Jinghuai; LIU Dan; LI Xiao

    2015-01-01

    A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea (from 313 to 1 600 m) and one station in shallow waters (87 m) during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./(10 cm2). A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera wereSabatieria,Linhystera,Aegialoalaimus andDaptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community (or station groups) in the sampling area. In terms of trophic structure, non-selective deposit feeders (1B) and selective deposit feeders (1A) were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea. The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices (H') ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indicesH' at the five stations in deep sea (over 200 m) were lower than that at the station in shallow waters (87 m). BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water depth.

  9. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    Science.gov (United States)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  10. Dual Sarcocystis neurona and Toxoplasma gondii infection in a northern sea otter from Washington state, USA

    Science.gov (United States)

    Lindsay, D.S.; Thomas, N.J.; Rosypal, A.C.; Dubey, J.P.

    2001-01-01

    Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.

  11. Quaternary palaeoceanographic changes in the northern South China Sea (ODP Site 1146): radiolarian evidence

    Science.gov (United States)

    Wang, Rujian; Clemens, Steven; Huang, Baoqi; Chen, Muhong

    2003-12-01

    The abundance and accumulation rates of siliceous microfossils in the northern South China Sea, including radiolarians, diatoms and sponge spicules, increased during most glacial intervals within the past 1100 kyr. Similar trends are observed in the index of thermocline surface radiolarians (TSR), diatom accumulation rates (DAR), charcoal accumulation rates (CAR) and the abundance of radiolarian species Cycladophora davisiana davisiana. Decreasing sea-surface temperature accompanied by increased seasonality since 900 ka is indicated by a decline in the tropical radiolarian assemblage, including Tetrapyle octacantha and Octopyle stenozona, and by an increase in the subtropical assemblage, including Pterocorys zancleus, Peromelissa phalacra and Ommatartuts tetrathalamus tetrathalamus. Rapid increases at about 800 to 700 ka of siliceous microfossils, charcoal, subsurface and intermediate radiolarians, as well as the TSR index and the DAR, imply a fundamental shift in climate and a shoaling thermocline. Although these fundamental changes in the silicious fauna and flora of the South China Sea take place within the context of a developing 100-kyr cycle, they do not change in step with changing sea-level as indicated by marine 18O. This is most clearly illustrated by the step-like increase in silica accumulation (radiolaria, diatoms and sponge spicules) at 680 ka. Rather, these fundamental changes probably reflect intensified surface productivity associated with enhanced East Asian winter-monsoon circulation. Copyright

  12. Linkages between sea-ice coverage, pelagic-benthic coupling, and the distribution of spectacled eiders: Observations in March 2008, 2009 and 2010, northern Bering Sea

    Science.gov (United States)

    Cooper, L. W.; Sexson, M. G.; Grebmeier, J. M.; Gradinger, R.; Mordy, C. W.; Lovvorn, J. R.

    2013-10-01

    Icebreaker-based sampling in the northern Bering Sea south of St. Lawrence Island in March of 2008, 2009, and 2010 has provided new data on overall ecosystem function early in the annual productive cycle. While water-column chlorophyll concentrations (5 µM. These data, together with other physical, biological, and nutrient data, are presented here in conjunction with observed sea-ice dynamics and the distribution of an apex predator, the Spectacled Eider (Somateria fischeri). Sea-ice dynamics in addition to benthic food availability, as determined by sedimentation processes, play a role in the distribution of spectacled eiders, which cannot always access the greatest biomass of their preferred bivalve prey. Overall, the data and observations indicate that the northern Bering Sea is biologically active in late winter, but with strong atmospheric and hydrographic controls. These controls pre-determine nutrient and chlorophyll distributions, water-column mixing, as well as pelagic-benthic coupling.

  13. Pollen record of the last 280 ka from deep sea sediments of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Environmental history of the northern continental shelf of the South China Sea during the last 280 ka BP, e.g. Marine Isotope Stages 1-8 (MIS 1-8) was reconstructed based on poi len record from the top 225m of ODP 1144 Site. During the interglacial periods, pollen assem blages are predominated by pine similar to those of the present day indicating that the environ ment of the interglacial periods was more or less close to that of today. Nevertheless, those from glacial periods are characterized by a large amount of herbaceous pollen, e.g. Artemisia,Gramineae, Cyperaceae, etc. inferring that grassland covered the merged continental shelf when the sea level lowered and the continental shelf was exposed. The exposed areas of the shelf were insignificant before MIS 5, but enlarged since MIS 4 and reached its maximum during MIS 2 ac cording to ratios of pollen percentages between pine and herbs. The history of different exposure of the shelf can be compared with transgression records of the coastal areas of China and might result from neotectonic movement of Chinese continent. Some changes also took place in the components of grassland growing on the shelf during glaciations. Gramineae is the main element at MIS 8. Then Artemisia increased upwards the profile and at last became the main component at the Last Glacial Maximum (MIS 2). Such changes in vegetation might be in response to cooler and drier climate.

  14. Reply to Comment by Xu et al. on "Sr-Nd isotope composition and clay mineral assemblages in eolian dust from the central Philippine Sea over the last 600 kyr: Implications for the transport mechanism of Asian dust" by Seo et al.

    Science.gov (United States)

    Seo, Inah; Lee, Yong Il; Yoo, Chan Min; Kim, Hyung Jeek; Hyeong, Kiseong

    2016-12-01

    Against Xu et al. (2016), who argued that East Asian Desert (EAD) dust that traveled on East Asian Winter Monsoon winds dominates over Central Asian Desert (CAD) dust in the Philippine Sea with presentation of additional data, we reconfirm Seo et al.'s (2014) conclusion that CAD dust carried on the Prevailing Westerlies and Trade Winds dominates over EAD dust in overall dust budget of the central Philippine Sea. The relative contribution of dust from EADs and CADs using clay mineral composition should be evaluated with elimination of mineralogical contribution from the volcanic end-member which is enriched in kaolinite and overestimate the contribution of EAD dust.

  15. Effects of Cross-axis Wind Jet Events on the Northern Red Sea Circulation

    Science.gov (United States)

    Menezes, V. V.; Bower, A. S.; Farrar, J. T.

    2016-12-01

    Despite its small size, the Red Sea has a complex circulation. There are boundary currents in both sides of the basin, a meridional overturning circulation, water mass formation in the northern part and an intense eddy activity. This complex pattern is driven by strong air-sea interactions. The Red Sea has one of the largest evaporation rates of the global oceans (2m/yr), an intricate and seasonally varying wind pattern. The winds blowing over the Northern Rea Sea (NRS, north of 20N) are predominantly southeastward along the main axis all year round; in the southern, they reverse seasonally due to the monsoonal regime. Although the winds are mostly along-axis in the NRS, several works have shown that sometimes during the boreal winter, the winds blow in a cross-axis direction. The westward winds from Saudi Arabia bring relatively cold dry air and dust from the desert, enhancing heat loss and evaporation off the Red Sea. These wind-jet events may contribute to increased eddy activity and are a trigger for water mass formation. Despite that, our knowledge about the cross-axis winds and their effect on NRS circulation is still incipient. In the present work we analyze 10-years of Quikscat scatterometer winds and altimetric sea surface height anomalies, together with 2-yrs of mooring data, to characterize the westward wind jet events and their impacts on the circulation. We show that the cross-axis winds are, indeed, an important component of the wind regime, explaining 11% of wind variability of the NRS (well-described by a 2nd EOF mode). The westward events occur predominantly in the winter, preferentially in January (about 15 events in 10-years) and have a mean duration of 4-5 days, with a maximum of 12 days (north of 22N). There are around 6 events per year, but in 2002-2003 and 2007-2008, twice more events were detected. The westward wind events are found to strongly modify the wind stress curl, causing a distinct positive/negative curl pattern along the main axis

  16. Security Force Assistance in the Philippines

    Science.gov (United States)

    2009-04-01

    34 ~"ř’ "CHINA,..-’ South ChintJ Sea -1:!" Luzon’ Strait ". , 1;:’~ 󈧄 200km 100 200nri Philippine Sea Source: The Central Intelligence Agency, The...tactics. The central Philippine government was generally uninterested because it was preoccupied with economic crises and corruption. is Insurgent Moro...making them extremely adept with speed and " banca " boats.3o The ASG worked with Ramzi Yoesef, mastermind of the 1993 World Trade Center bombings and

  17. Postglacial sedimentary regime around northern Sylt, South-eastern North Sea, based on shallow seismic evidence

    DEFF Research Database (Denmark)

    Boldreel, Lars Ole; Kuijpers, Antoon; Madsen, Emil B

    2010-01-01

    During the past 5 years the coastal zone offshore the northern part of the island of Sylt, has been investigated by sparker seismics and high-resolution subbottom profiling. The North Sea sector of the area is characterized by northward-directed sediment bypass as a result of strong long-shore (t......During the past 5 years the coastal zone offshore the northern part of the island of Sylt, has been investigated by sparker seismics and high-resolution subbottom profiling. The North Sea sector of the area is characterized by northward-directed sediment bypass as a result of strong long......-shore (tidal) currents heading towards the Lister Tief. The southern part of Lister Tief is characterized by the presence of a major dune field with up to 8 m high compound dunes with wavelengths up to 350 m indicative of easterly-directed sediment transport (flood dominated). Further to the northwest...... by the presence of minor dunes, indicative of flood-current control, apart from a central zone where ebb-tide is responsible for northward-directed sediment transport. Sparker seismic and Chirp III data are consistent with processes having been persistent throughout the Holocene. Based on the study a model...

  18. Climate warming and interannual variability of phytoplankton phenology in the Northern Red Sea

    KAUST Repository

    Gittings, John

    2016-12-01

    In agreement with global patterns of climate change and increasing temperatures in the tropical oceans, the Northern Red Sea (NRS) has been warming over the last few decades. Using 18 years of remotely-sensed chlorophyll-a data (Chl-a, an index of phytoplankton biomass), we investigate the potential impacts of climate warming on phytoplankton abundance and phenology in the Northern Red Sea by exploring the mechanistic links with the regional physical environment. The results of the analysis reveal that, in accordance with other tropical ecosystems, phytoplankton biomass in the NRS will decrease in response to warmer climate scenarios. This is attributed to lower heat fluxes (heat loss to the atmosphere) during the bloom period, and enhanced vertical stratification, which prevents vertical mixing of nutrients into the euphotic layer. In addition, we show that during warmer conditions (when heat fluxes are weakened), the winter bloom initiates significantly later (by up to 10 weeks) and its duration is considerably reduced. The biological implications of alterations to phytoplankton phenology may include increased larval mortality of pelagic species, reduced recruitment, fisheries impacts and changes to community structure.

  19. Ecological aspects in economic structure development in Northern Sea of Azov region

    Directory of Open Access Journals (Sweden)

    В’ячеслав Степанович Волошин

    2016-07-01

    Full Text Available A comparative analysis of the quantitative model following the patterns of ecological development under the conditions of a free economic zone in the region of Northern Sea of Azov has been performed. The proportions and the annual growth rate of investment in the steel industry and alternative sectors of economy and their impact on the pollution level in the region have been defined. It has been shown that creation of the project of free economic zone in industrially developed regions must be followed by not only calculations of the investment policy economic efficiency, but also by the obligatory analysis of its influence on the level of ecological and social wellbeing of the population as well. Estimated data in proportions of investment policy in the region, ecologically safe and directed on welfare growth of the population have been defined on the basis of the analysis of the numerical model made up with the use of J. Forrester dynamic simulation technique and adapted for basic economic conditions. Problems of further researches are: refinement of some relationships to be able to calculate levels and rates dynamics of ecological and social blocks of the model to create the program of a steady development of Northern Sea of Azov region

  20. Impact of winter cooling on the northern part of the Black Sea.

    Science.gov (United States)

    Savchenko, Anatolii

    2016-07-01

    Climate change in the future may have a negative impact on many countries due to the increasing surface temperature and sea level rise. Probably, unprecedented largest positive trend of surface temperature, which observed since the mid XX century, has associated with increasing human activities around the world. Moreover, this warming will continue in this century, and at the end of the XXI century will be 2 - 5 ºC. Thus, investigation and monitoring of current climate are very important and necessary tasks. Regional model data (downscaling) and satellite data are used, because of underdeveloped network of meteorological stations in the northern part of the Black Sea region. Experiment of downscaling was carried out for the Black Sea region with a high spatial resolution of 0.22° x 0.22° for 1958 - 2007(daily values). For the Black Sea were also used satellite data of sea surface temperature(SST) from MyOcean-2 Project, which CNR(Rome) has reprocessed Pathfinder V5.2 (PFV52) AVHRR data over period 1981 - 2012 with daily gap-free maps (L4) at the original PFV52 resolution at 0.04° x 0.04°. Correlation between satellite SST and surface temperature from regional model climate are amounted 0,99. Thus, surface temperature of model and satellite data for the Black Sea is much correlated between yourself. The following integral characteristics of the Black Sea are referred to the area of sea limited by the 44 - 47º N and 28 - 34º E. Maximum cooling of the north-western part of the Black Sea in winter is occurs after invasion of cold air across the northern border of the basin. In addition, this water area is also interesting in the presence of her huge oil and gas reserves, as well as the construction of liquefied gas (crude oil) terminals. The maximum values of total heat flux (sensible + latent heat fluxes= Q) corresponding to the minimum values of SST are observed during the periods of the negative phase of the NAO. Besides, fluxes with extreme days P (Q) = 95

  1. Standing stock and community structure of photosynthetic picoplankton in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    NING Xiuren; LI W K W; CAI Yuming; LIU Chenggang; SHI Junxian

    2005-01-01

    The investigation on community structure of standing stock of photosynthetic picoplankton: Synechococcus (Syn), Prochlorococcus (Pro) and Picoeukaryotes (Euk) and their environmental regulation mechanisms in the northern South China Sea was carried out in the summer of 1999. The results showed that the average abundances of Syn, Pro and Euk in the study sea areas were (5.0± 7.6)×104cell/cm3 (51%), (4.6±4.2)×104 cell/cm3 (47%) and (1.8±1.1)×l03 cell/cm3 (2%) respectively, and those of their carbon biomass were (12.5±18.9) μg/dm3 (74%), (2.7±2.5) μg/dm3 (16 %) and (1.7±1.0) μg/dm3 (10%). The most of high values of Syn appeared in the estuaries, coastal zone and continental shelf in the sea area to the east of Leizhou Peninsula and Hainan Island where nutrients were rich, and those appeared in the Beibu Gulfwere the second, while those appeared in continental slope and open sea were tens times lower than the above those. Its distribution in water column was mainly above the thermocline and its abundance below it sharply decreased. Two different populations of Pro were found, the surface population and deep one. The distribution pattern of the former was similar to that of Syn; while with marked difference from that of the former, the abundance and biomass of the latter markedly increased towards outer sea, continental slope and open sea where nutrients were poor; the high values in the water column mainly appeared at the bottom of euphoric zone and above the nitrocline, where it often vigorously grow. The distribution difference of Euk in the various sea areas is not as obvious as those of Syn and Pro, but it was high in coastal and shelf waters and low in continental slope and open sea. The high values in the water column were mostly appeared at the bottom of euphoric zone. This difference of distribution pattern for the three type of photosynthetic picoplankton depends on environmental effects and their ecophysiological differences.

  2. Winter climate change and sea ice-atmosphere interaction at high northern latitudes in ERA40 dataset

    Institute of Scientific and Technical Information of China (English)

    Liu Xiying

    2006-01-01

    Based on the reanalysis dataset ERA40 of European Center of Medium Range Weather Forcast (ECMWF), winter climate change and characteristics of sea ice-atmosphere interaction at high northern latitudes for recent several tens of years are analyzed. Superposed upon the background of global warming, the amplitude of temperature increase in winter at high northern latitudes is bigger and it exhibits different features in different regions. From the end of 1970 s, the Greenland Sea, the Barents Sea and most part of Euro-Asian continent and North American continent are getting warmer, whereas the Labrador Sea, the Greenland and the area around the Bering Strait are getting colder. Meanwhile, the sea level pressure in the central part of the northern polar region and the place where the climatic Icelandic low exist decreases, but in places farther southward it increases. Since the 1970 s, the sensible heat flux and latent heat flux sent to the atmosphere from the Greenland Sea and the Barents Sea has increased, this is mainly due to the reduction of sea ice concentration and the weakening of insulator and shield effect of the solid ice accordingly caused by the increase of air temperature. In sea ice free area of the Norwegian Sea, the sensible heat flux and latent heat flux sent to the atmosphere has reduced due to decrease of temperature and humidity differences between the air and the sea surface caused by increase of air temperature and humidity. In the Labrador Sea, due to decrease of air temperature and humidity and increase of temperature and humidity differences between the air and the sea surface accordingly, the sea gives more sensible heat flux and latent heat flux to the air. This will lead to the growth of sea ice extent there. The features of linear regression of sea level pressure, sea ice concentration and sum of sensible heat flux and latent heat flux toward time series of the leading mode of EOF expansion of surface air temperature are close to those of

  3. Zooxanthellate zoantharians (Anthozoa: Hexacorallia: Zoantharia: Brachycnemina) in the northern Red Sea

    KAUST Repository

    Reimer, James Davis

    2017-05-12

    The Red Sea was one of the first areas of the Indo-Pacific to be investigated by marine taxonomists, and the literature on suborder Brachycnemina (Anthozoa: Hexacorallia: Zoantharia) for this region dates from the early nineteenth century. However, in the last 100 years there has been only one focused study on this group in the Red Sea. In the present study, specimens collected from the Saudi Arabian coast of the northern half of the Red Sea were phylogenetically analyzed by sequencing nuclear internal transcribed spacer regions of ribosomal DNA (ITS-rDNA), mitochondrial cytochrome oxidase subunit I (COI), and 16S ribosomal DNA (16S–rDNA). The new results were compared with historical data in the literature and recent results from the Persian Gulf and the southeastern coast of Africa. Results show the presence of six to seven potential Brachycnemina species in the Red Sea; five to six Palythoa species (Palythoa mutuki, P. tuberculosa, P. cf. heliodiscus, P. aff. heliodiscus, and one to two species within the P. sp. “sakurajimensis” group) together with Zoanthus sansibaricus. While P. mutuki, P. tuberculosa, and Z. sansibaricus are known to be widely distributed in the Indo-Pacific, P. cf. heliodiscus and P. sp. “sakurajimensis” have not been reported from the Persian Gulf or the southeastern coast of Africa, and the current results represent large range extensions for these two species. Only one of the observed species, P. aff. heliodiscus, is potentially endemic to the Red Sea, further demonstrating the generally wide distributions of most zooxanthellate Brachycnemina species.

  4. Pathogen exposure and blood chemistry in the Washington population of northern sea otters (Enhydra lutris kenyoni)

    Science.gov (United States)

    White, C. LeAnn; Schuler, Krysten L.; Thomas, Nancy J.; Webb, Julie L.; Saliki, Jeremiah T.; Ip, Hon S.; Dubey, J.P.; Frame, Elizabeth R.

    2013-01-01

    Northern sea otters (Enhydra lutris kenyoni) from Washington State, United States were evaluated in 2011 to determine health status and pathogen exposure. Antibodies to Brucella spp. (10%) and influenza A virus (23%) were detected for the first time in this population in 2011. Changes in clinical pathology values (serum chemistries), exposure to pathogens, and overall health of the population over the last decade were assessed by comparing 2011 data to the data collected on this population in 2001–2002. Several serum chemistry parameters were different between study years and sexes but were not clinically significant. The odds of canine distemper virus exposure were higher for otters sampled in 2001–2002 (80%) compared to 2011 (10%); likelihood of exposure significantly increased with age. Prevalence of exposure to Sarcocystis neurona was also higher in 2001–2002 (29%) than in 2011 (0%), but because testing methods varied between study years the results were not directly comparable. Exposure to Leptospira spp. was only observed in 2001–2002. Odds of Toxoplasma gondii exposure were higher for otters sampled in 2011 (97%) than otters in 2001–2002 (58%). Substantial levels of domoic acid (n = 2) and saxitoxin (n = 2) were found in urine or fecal samples from animals sampled in 2011. No evidence of calicivirus or Coxiella burnetii exposure in the Washington population of northern sea otters was found in either 2001–2002 or 2011. Changes in exposure status from 2001–2002 to 2011 suggest that the Washington sea otter population may be dealing with new disease threats (e.g., influenza) while also increasing their susceptibility to diseases that may be highly pathogenic in naïve individuals (e.g., canine distemper).

  5. Footprints of Obliquely Incident Internal Solitary Waves near the Shelf Break, northern South China Sea

    Science.gov (United States)

    Ma, X.; Yan, J.; Hou, Y.; Lin, F.; Zheng, X.

    2016-12-01

    The northern South China Sea provides prominent examples of internal waves, however, rare studies have been done on the associated bedforms and sediment transport near the shelf break. Here, we report the unique data of bedform details which probably caused by the internal solitary waves and internal tides near the shelf break in the areas west of Dongsha Atoll. In the study area, most internal solitary waves (ISWs) are found to propagate onto the shelf obliquely in an approximately 290° through the MODIS image. Several typical events of ISWs were also captured during our observation by an mooring system on the continental slope. Bottom current data near the shelf break showed that extremely strong speed (exceeding 80 cm/s) occurred when the obliquely incident ISWs propagated. The strong currents have the capability to move coarse grains or suspend and transport fine grains but, cannot change the long-term trend of sediment transport on the slope (γ/c>1). Two types of sand waves were also found on the seabed. The upslope-dipping sand waves (type 1) are only found at depths of 120-150 m with flat crests and intersecting the depth contours, being ascribed to the obliquely incident ISWs. In contrast, the downslope-dipping sand waves (type 2) are parallel to the depth contours and obviously migrated over eight months, which were probably caused by internal tides. The ISWs could also produce along-slope currents to form and maintain channels on seabed with a larger gradient (γ>0.8°). The bedforms are likely widespread near the shelf break in the northern South China Sea and other seas but are limited on mild slopes where ISWs do not break. Additional detailed research needs to be deployed on wave behaviors, sediment transport, and the bedforms associated with obliquely incident ISWs.

  6. Late Quaternary sea-ice history of northern Fram Strait/Arctic Ocean

    Science.gov (United States)

    Kremer, Anne; Stein, Rüdiger; Fahl, Kirsten; Matthießen, Jens; Forwick, Matthias; O'Regan, Matt

    2016-04-01

    the Arctic Ocean. Furthermore, the repetitive advance and retreat of the Svalbard Barents Sea Ice Sheet might have influenced the terrigenous input and the environmental setting north of Svalbard, as reflected in the sediment composition of Core PS92/039-2. References Belt, S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of paleo sea ice: IP25. Organic Geochemistry 38, 16-27. Müller, J., Massé, G., Stein, R., Belt, S.T., 2009. Variability of sea-ice conditions in the Fram Strait over the past 30,000 years. Nature Geoscience 2 (11), 772-776. Müller, J., Wagner, A., Fahl, K., Stein, R., Prange, M., Lohmann, G., 2011. Towards quantitative sea ice reconstructions in the northern North Atlantic: a combined biomarker and numerical modelling approach. Earth and Planetary Science Letters 306 (3,4), 137-148. Peeken, I. (Ed.), 2015. Cruise report of Arctic Expedition PS92: TRANSSIZ Cruise from Bremerhaven to Longyearbyen (19.05.2015 - 28.06.2015), in preparation.

  7. Tephrostratigraphic record from the Northern Ionian Sea and geochemical analytic methods

    Science.gov (United States)

    Caron, B.; Siani, G.; Sanatcroce, R.; Zanchetta, G.; Paterne, M.; Villemant, B.

    2012-12-01

    A detailed tephrostratigraphic study supported by stable isotope (δ18O) analyses and AMS 14C dating was carried out on a high sedimentation rate deep-sea core recovered in the northern Ionian Sea. Eight tephra layers were recognised, all originated from explosive eruptions of southern Italian volcanoes (Caron et al., 2012). These tephra layers are correlated with terrestrial proximal counterparts and with both marine and lacustrine tephra already known in the central Mediterranean area. The oldest tephra (dated at ca. 19.4 ka cal BP) is tentatively correlated to the Monte Guardia eruption from Lipari Island. Two other rhyolitic tephra layers were correlated with the explosive volcanic activity of Lipari Island: Gabellotto-Fiumebianco/E-1 (8.3 ka cal BP) located close to the interruption of Sapropel S1 deposit, and Monte Pilato (ca. AD 1335) in the uppermost part of the core. The Na-phonolitic composition of the other five recognised tephra layers indicates the Somma-Vesuvius as the source. The composition is quite homogeneous among the five tephra layers, and fits that of the Mercato proximal deposits. Beyond the striking chemical similarity with the Mercato eruption, these tephra layers span over ca. 2000 years, preventing correlation with the single well known Plinian eruption of the Somma-Vesuvius. Therefore, at least two of these tephra layers were assigned to an interplinian activity of the Somma-Vesuvius between the eruptions of Mercato and Avellino, even though these eruptions remains poorly constrained in the proximal area. To correlate these MA group tephra layer, we improve trace element analysis by ICP-MS on micro quantity of material (from 50mg to à.1mg). By contrast, the most prominent tephra layer (2mm white tephra visible at naked eyes) was found within the S1a Sapropel interval. Despite the possible complication for the presence of similar eruption with different ages we argue that Mercato is probably a very good marker for the onset of sapropelic

  8. Polar bear population status in the northern Beaufort Sea, Canada, 1971-2006.

    Science.gov (United States)

    Stirling, Ian; McDonald, Trent L; Richardson, E S; Regehr, Eric V; Amstrup, Steven C

    2011-04-01

    Polar bears (Ursus maritimus) of the northern Beaufort Sea (NB) population occur on the perimeter of the polar basin adjacent to the northwestern islands of the Canadian Arctic Archipelago. Sea ice converges on the islands through most of the year. We used open-population capture-recapture models to estimate population size and vital rates of polar bears between 1971 and 2006 to: (1) assess relationships between survival, sex and age, and time period; (2) evaluate the long-term importance of sea ice quality and availability in relation to climate warming; and (3) note future management and conservation concerns. The highest-ranking models suggested that survival of polar bears varied by age class and with changes in the sea ice habitat. Model-averaged estimates of survival (which include harvest mortality) for senescent adults ranged from 0.37 to 0.62, from 0.22 to 0.68 for cubs of the year (COY) and yearlings, and from 0.77 to 0.92 for 2-4 year-olds and adults. Horvtiz-Thompson (HT) estimates of population size were not significantly different among the decades of our study. The population size estimated for the 2000s was 980 +/- 155 (mean and 95% CI). These estimates apply primarily to that segment of the NB population residing west and south of Banks Island. The NB polar bear population appears to have been stable or possibly increasing slightly during the period of our study. This suggests that ice conditions have remained suitable and similar for feeding in summer and fall during most years and that the traditional and legal Inuvialuit harvest has not exceeded sustainable levels. However, the amount of ice remaining in the study area at the end of summer, and the proportion that continues to lie over the biologically productive continental shelf (< 300 m water depth) has declined over the 35-year period of this study. If the climate continues to warm as predicted, we predict that the polar bear population in the northern Beaufort Sea will eventually decline

  9. Study on the storm surges induced by cold waves in the Northern East China Sea

    Science.gov (United States)

    Mo, Dongxue; Hou, Yijun; Li, Jian; Liu, Yahao

    2016-08-01

    Cold wave, a kind of severe weather system, can bring strong wind and induce significant sea level rise to the Northern East China Sea. Based on CFSR data, the study shows the monthly distributions of invaded days and the spatiotemporal distributions of cold-wave wind direction and wind speed. A three-dimensional numerical model (ROMS) was developed to study storm surges induced by cold waves. The role of wind direction, wind speed, wind duration, extratropical cyclone and tide-surge interaction is investigated by conducting different sensitivity experiments. The results indicate that storm surges mainly happen at the coasts perpendicular to the wind directions. Surge range and time lag are related to the geometry of the basin and the continental shelf. The response of the sea-level fluctuations to cold wave indicates that there is a positive correlation between crests and wind speed, a negative correlation between troughs and wind speed, but no obvious correlations to wind duration. Coupled weather cold waves, which yield a larger range and a multi-peak structure of surges, can be classified according to cold wave tracks and extratropical cyclones. The tide-surge interaction has an obvious and different effect on the magnitudes and phases of storm surges for different tidal stages.

  10. Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni)

    Science.gov (United States)

    Von Biela, V.R.; Gill, V.A.; Bodkin, J.L.; Burns, Jennifer M.

    2009-01-01

    Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average AFR) is predicted to be older than in populations below K. Differences between the trajectories of northern sea otter (Enhydra lutris kenyoni) populations in Alaska provides an opportunity to examine phenotypic plasticity. Using premolar teeth or reproductive tracts, we estimated average AFR from demographically distinct populations of sea otters in Alaska. We obtained samples from 2 populations near K, Prince William Sound (PWS) and the Aleutian Archipelago (archived samples), and from 2populations below K, the Kodiak Archipelago and Sitka. The average AFR was lower in populations below K (3.60 years ??0.16 SD)compared to those near K (4.21 ?? 0.13 years, P phenotypic plasticity in sea otters. Our findings highlight the value of using average AFR as a tool for monitoring mammalian populations. ?? 2009 American Society of Mammalogists.

  11. Initial insights into the age and origin of the Kubuqi sand sea of northern China

    Science.gov (United States)

    Yang, Xiaoping; Forman, Steven; Hu, Fangen; Zhang, Deguo; Liu, Ziting; Li, Hongwei

    2016-04-01

    The Kubuqi Desert is the only active sand sea in the semiarid regions of northern China and occurs along the southern margin of the Yellow River. Little is known about the age and origin of this large (17,000 km2) sand sea with a present annual precipitation of 200-480 mm. Sand drift potentials indicated net capable winds for aeolian transport are from the northwest, though winds are stronger to north beyond the dune field than within the sand sea. Geomorphic and stratigraphic observations indicate that Holocene aeolian sand often drapes over bedrock and river terraces as a palimpsest landscape. Field investigations identified four stratigraphic sections with multiple aeolian sand units and palaeosols, with age control by optically stimulated luminescence (OSL) dating of quartz grains. Palaeosols are weakly developed, mostly accumulative A horizon with organic carbon content farming from lost cities in the Kubuqi Desert during the Han (206 B.C. - A.D. 220) and the Tang (A.D. 608 - 907) Dynasties. Also, variable discharge of the Yellow River with local diversions for irrigation and throughout the catchment resulted in possibly an increased supply of aeolian particles for dune field expansion in the past 2 ka.

  12. Wetland Responses to Sea Level Rise in the Northern Gulf of Mexico

    Science.gov (United States)

    Alizad, K.; Bilskie, M. V.; Hagen, S. C.; Medeiros, S. C.; Morris, J. T.

    2016-12-01

    Coastal regions are vulnerable to flood risk due to climate change, sea level rise, and wetland losses. The Northern Gulf of Mexico (NGOM) is a region in which extreme events are projected to be more intense under climate change and sea level rise scenarios [Wang et al., 2013; Bilskie et al., 2014]. Considering increased frequency and intensity of coastal flooding, wetlands are valuable natural resources that protect shorelines by dissipating waves and storm surges [Costanza et al., 2008]. Therefore, it is critical to investigate the response of salt marsh systems in different estuaries to sea level rise in the NGOM and their effects on storm surges to inform coastal managers to choose effective restoration plans. This research applies the coupled Hydro-MEM model [Alizad et al., 2016] to study three different estuarine systems in the NGOM. The model incorporates both sea level rise rate and feedbacks between physics and biology by coupling a hydrodynamic (ADCIRC) and salt marsh (MEM) model. The results of the model provide tidal hydrodynamics and biomass density change under four sea level rise projections during a 100-year period. The results are used to investigate marsh migration path in the estuarine systems. In addition, this study shows how marsh migration and biomass density change can impact storm surge modeling. The results imply the broader impacts of sea level rise on the estuarine systems in the NGOM. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, P. Bacopoulos, M. V. Bilskie, J. Weishampel, and S. C. Medeiros (2016), A coupled, two-dimensional hydrodynamic-marsh model with biological feedback, Ecological Modeling, 327, 29-43. Bilskie, M. V., S. C. Hagen, S. C. Medeiros, and D. L. Passeri (2014), Dynamics of sea level rise and coastal flooding on a changing landscape, Geophysical Research Letters, 41(3), 927-934. Costanza, R., O. Pérez-Maqueo, M. L. Martinez, P. Sutton, S. J. Anderson, and K. Mulder (2008), The Value of Coastal Wetlands for Hurricane

  13. Seismic ACROSS Transmitter Installed at Morimachi above the Subducting Philippine Sea Plate for the Test Monitoring of the Seismogenic Zone of Tokai Earthquake not yet to Occur

    Science.gov (United States)

    Kunitomo, T.; Kumazawa, M.; Masuda, T.; Morita, N.; Torii, T.; Ishikawa, Y.; Yoshikawa, S.; Katsumata, A.; Yoshida, Y.

    2008-12-01

    reflected wave from an anticipated fault plane of Tokai Earthquake, the boundary between Eurasian lithosphere and the subducting Philippine Sea Plate. Further several trials of new transmission protocol and also remote control are being made for the transmitter network of the next generation. The whole system appears working well as reported by Yoshida et al. (2008, This meeting).

  14. Coastal vulnerability assessment of the Northern Gulf of Mexico to sea-level rise and coastal change

    Science.gov (United States)

    Pendleton, E.A.; Barras, J.A.; Williams, S.J.; Twichell, D.C.

    2010-01-01

    A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise along the Northern Gulf of Mexico from Galveston, TX, to Panama City, FL. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate of relative sea-level rise, historical shoreline change rate, mean tidal range, and mean significant wave height. The rankings for each variable are combined and an index value is calculated for 1-kilometer grid cells along the coast. The CVI highlights those regions where the physical effects of sea-level rise might be the greatest. The CVI assessment presented here builds on an earlier assessment conducted for the Gulf of Mexico. Recent higher resolution shoreline change, land loss, elevation, and subsidence data provide the foundation for a better assessment for the Northern Gulf of Mexico. The areas along the Northern Gulf of Mexico that are likely to be most vulnerable to sea-level rise are parts of the Louisiana Chenier Plain, Teche-Vermillion Basin, and the Mississippi barrier islands, as well as most of the Terrebonne and Barataria Bay region and the Chandeleur Islands. These very high vulnerability areas have the highest rates of relative sea-level rise and the highest rates of shoreline change or land area loss. The information provided by coastal vulnerability assessments can be used in long-term coastal management and policy decision making.

  15. Drivers of Holocene sea-level change - using a global database of relative sea-level records from the Northern and Southern Hemisphere

    Science.gov (United States)

    Horton, Benjamin; Khan, Nicole; Ashe, Erica; Kopp, Robert

    2016-04-01

    Many factors give rise to relative sea-level (RSL) changes that are far from globally uniform. For example, spatially variable sea-level responses arise because of the exchange of mass between ice sheets and oceans. Gravitational, flexural, and rotational processes generate a distinct spatial pattern - or "fingerprint" - of sea-level change associated with each shrinking land ice mass. As a land ice mass shrinks, sea-level rise is greater in areas geographically distal to the ice mass than in areas proximal to it, in large part because the gravitational attraction between the ice mass and the ocean is reduced. Thus, the U.S. mid-Atlantic coastline experiences about 50% of the global average sea-level-rise due to Greenland Ice Sheet melt, but about 120% of the global average due to West Antarctic Ice Sheet melt. Separating the Greenland and Antarctic ice sheet contributions during the past 7,000 years requires analysis of sea-level changes from sites in the northern and southern hemisphere. Accordingly we present a global sea-level database for the Holocene to which we apply a hierarchical statistical model to: (1) estimate the Global Mean Sea Level Signal; (2) quantify rates of change; (3) compare rates of change among sites, including full quantification of the uncertainty in their differences; and (4) test hypotheses about the sources of meltwater through their sea-level fingerprints.

  16. Studies in Philippine Languages and Cultures.

    Science.gov (United States)

    Brainard, Sherri, Ed.

    2001-01-01

    This issue of Studies in Philippine Languages and Cultures contains the following articles: "Functions of Locatives in Northern Subanen Expository and Hortatory Discourse" (Josephine Sanicas-Daguman); "Functions of Demonstratives in Sama Bangingi' Expository Discourse" (John Blakely); "A Brief Look at Sinama Basic Verbs…

  17. Provenance of a prominent sediment drift on the northern slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    SHAO; Lei

    2001-01-01

    [1]Sarnthein, M., Pflaumann, U., Wang, P. X. et al., Preliminary report on Sonne-95 cruise “Monitor Monsoon“ to the South China Sea, Reports, Geol.-Palaont. Inst. Univ. Kiel, 68, 1994, 125.[2]Wang, L., Sarnthein, M., High-reso1ution paleoceanographic records during the last 4000 years from the northern slope of the South China Sea, Quaternary Sciences, 1999, 1:27-31.[3]Wang, P.X., Prell, W. L., Blum, P. et al., Proceedings of the Ocean Drilling Program, Initial Reports South China Sea,Volume 184, College Station TX (Ocean Drilling Program), 2000, 18-20.[4]Shao, L., Dong, W., Liu, Z. et al., Trace elements analysis of sediments from the South China Sea, Journal of Tong ji Uni versity, 1999, 27(supp.): 55-60.[5]Taylor, S. R., McLennan, S. M., The Continental Crust: Its Composition and Evolution, in An Examination of the Geo chemical Record Preserved in Sedimentary Rocks, Oxford: Blackwell Scientific Publication, 1985, 1-301.[6]McLennan, S. M., Rare earth elements in sedimentary rocks, Influence of provenance and sedimentary processes, in Geo chemistry and Mineralogy of Rare Earth Elements (ed. Lipin, B. R. et al.), Washington: The Mineralogical Society of America, 1989, 169-200.[7]McLennan, S. M., Hemming, S., McDaniel, M. J. et al., Geochemical approaches to sedimentation, provenance and tec tonics, in Processes Controlling the Composition of Clastic Sediments (ed. Jonhanson, M. J. et al.), Boulder: Geological Society of America, Special Paper 284, 1993, 21-40.[8]Rollinson, H. R., Using Geochemical Data: Evaluation, Presentation, Interpretation, London: Longman Scientific, Tech nical, 1993, 352.[9]Cullers, R. L., Basu, A., Suttner, L. J., Geochemical signature of provenance in sand-mixed material in soils and stream sediments near the Tobacco Root batholith, Montana, USA, Chem. Geol., 1988, 70: 335-348.[10]Bhatia, M. R., Crook, K. A. W., Trace element characteristics of graywackes and tectonic setting discrimination of

  18. Assessment of the sources of sedimentary organic matter in the Bohai Sea and the northern Yellow Sea using biomarker proxies

    Science.gov (United States)

    Xing, Lei; Hou, Di; Wang, Xinchen; Li, Li; Zhao, Meixun

    2016-07-01

    To evaluate the applicability of source proxies and to assess the sources of sedimentary organic matter in the Bohai Sea (BS) and the northern Yellow Sea (NYS), we analyzed total organic carbon (TOC), total nitrogen (TN), δ13C of TOC, n-alkanes, phytoplankton biomarkers, and glycerol dialkyl glycerol tetraethers (GDGTs) including branched GDGTs (brGDGTs) in 60 surface sediment samples covering the BS and the NYS. Spatial distribution comparison and principal component analysis indicate that with the exception of brGDGTs, terrestrial biomarkers have different spatial distribution pattern from marine biomarkers, suggesting that the sources control the distributions of these biomarkers in spite of hydrodynamic forcing. Significantly positive correlation (R2 = 0.5) between TOC normalized brGDGTs content and TOC normalized crenarchaeol content suggested in situ production of brGDGTs in the BS and the NYS. The δ13C values, TMBR [terrestrial and marine biomarker ratio: (C27 + C29 + C31n-alkanes)/[(C27 + C29 + C31n-alkanes) + (brassicasterol + dinosterol + alkenones)] ] and BIT (branched isoprenoid tetratether index) proxy indicated high terrestrial organic matter (TOM) input near the Huanghe River Estuary, while TOC/TON did not reveal similar distribution pattern. Quantitative estimates of TOM using a binary model revealed much higher TOM percentage from δ13C (avg. 58%) and TMBR (avg. 31%) than from BIT (avg. 7.4%). Our results suggest that, owing to significant in situ production of brGDGTs, the BIT is not a good proxy for indicating soil OM contribution in marine sediments from the BS and the NYS.

  19. The Pianosa Contourite Depositional System (Northern Tyrrhenian Sea): drift morphology and Plio-Quaternary stratigraphic evolution

    Science.gov (United States)

    Miramontes Garcia, Elda; Cattaneo, Antonio; Jouet, Gwenael; Thereau, Estelle; Thomas, Yannick; Rovere, Marzia; Cauquil, Eric; Trincardi, Fabio

    2016-04-01

    The Pianosa Contourite Depositional System (CDS) is located in the Corsica Trough (Northern Tyrrhenian Sea), a confined basin dominated by mass transport and contour currents in the eastern flank and by turbidity currents in the western flank. The morphologic and stratigraphic characterisation of the Pianosa CDS is based on multibeam bathymetry, seismic reflection data (multi-channel high resolution mini GI gun, single-channel sparker and CHIRP), sediment cores and ADCP data. The Pianosa CDS is located at shallow to intermediate water depths (170 to 850 m water depth) and is formed under the influence of the Levantine Intermediate Water (LIW). It is 120 km long, has a maximum width of 10 km and is composed of different types of muddy sediment drifts: plastered drift, separated mounded drift, sigmoid drift and multicrested drift. The reduced tectonic activity in the Corsica Trough since the early Pliocene permits to recover a sedimentary record of the contourite depositional system that is only influenced by climate fluctuations. Contourites started to develop in the Middle-Late Pliocene, but their growth was enhanced since the Middle Pleistocene Transition (0.7-0.9 Ma). Although the general circulation of the LIW, flowing northwards in the Corsica Trough, remained active all along the history of the system, contourite drift formation changed, controlled by sediment influx and bottom current velocity. During periods of sea level fall, fast bottom currents often eroded the drift crest in the middle and upper slope. At that time the proximity of the coast to the shelf edge favoured the formation of bioclastic sand deposits winnowed by bottom currents. Higher sediment accumulation of mud in the drifts occurred during periods of fast bottom currents and high sediment availability (i.e. high activity of turbidity currents), coincident with periods of sea level low-stands. Condensed sections were formed during sea level high-stands, when bottom currents were more sluggish

  20. Priorities of the strategic management and planning of the Northern Sea Route

    Directory of Open Access Journals (Sweden)

    Evgeniy E. Plisetskiy

    2016-04-01

    Full Text Available The article is devoted to the analysis of the main socio-economic indicators of 10 subjects of the Russian Federation, with the coastal areas adjacent to the water area of the Northern Sea Route. The author studied the strategy of socio-economic development of the North and Far East Russia. The planned development of the NSR provides alignment of a unified system of public-private management of transportation artery and the implementation of other strategic activities. It is necessary to establish a single governing body, modernization of the Arctic transport system, pro-duction of high-tech products and marine technology for the home market, building a rear port infrastructure, container terminals, customs warehouses and logistics centers.

  1. Phytoplankton transport to coral reefs by internal solitons in the northern South China Sea

    Science.gov (United States)

    Wang, Yu-Huai

    2016-09-01

    Evidence is presented that waters containing high concentrations of chlorophyll are transported by internal waves to the fore-reef slope of Dongsha Atoll in the northern South China Sea. High vertical resolution mooring measurements of temperature, pressure, and chlorophyll fluorescence revealed that the internal soliton cores could transport chlorophyll vertically downward and increase concentrations by an order of magnitude near the seafloor, compared to background levels. The reef areas that are potentially nourished by the pulses of phytoplankton are dominated by alcyonacean soft corals, while other reef areas that are less or not at all affected by internal waves are dominated by scleractinian hard corals. This suggests that the delivery of phytoplankton by internal solitons provides a plentiful food source that benefits the growth of soft corals.

  2. MARINE BIOFOULING IN OFFSHORE AREAS SOUTH OF HAINAN ISLAND, NORTHERN SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This study on the characteristics of fouling communities in offshore areas south of Hainan Island, northern South China Sea, was conducted at four sites there. At each station, test panels on iron frames were hung on the mooring system at different depths. Data on biofouling were mainly obtained by examination of the fouled test panels. Organisms attached to buoys and anchors were scraped off and examined also. The results showed that the thickness and biomass of marine growth that increased the fluid loading on offshore installations depended to a large extent on hard foulers, i.e. mollusks and acorn barnacles. Algae, hydroids, stalked barnacles and bryozoans were important fouling species. The occurrence frequency and biomass of acorn barnacles decreased with increasing distance from the shore.

  3. Coccolithophore diversity and dynamics at a coastal site in the Gulf of Trieste (northern Adriatic Sea)

    Science.gov (United States)

    Cerino, Federica; Malinverno, Elisa; Fornasaro, Daniela; Kralj, Martina; Cabrini, Marina

    2017-09-01

    Two years-data (May 2011-February 2013) obtained from a monthly sampling carried out at the coastal long term Ecological Research station C1-LTER in the Gulf of Trieste (northern Adriatic Sea) were analysed to describe the seasonal dynamics and diversity of coccolithophore assemblages and to assess their relationship with environmental forcing. Coccolithophores represented 10.7% of the total Utermöhl phytoplankton that were mainly dominated by small (Statistical analyses recognized four distinct groups, corresponding to seasonal variations of environmental conditions. Considering the two years, some species displayed a recurrent seasonal pattern highlighting possible species-specific ecological requirements, while others showed an interannual variability probably due to local factors.

  4. Experience on offshore cathodic protection retrofitting in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Guo Jinwen; L. Patterson; A. Amorelli; D. Condanni; B. Bazzoni

    2003-01-01

    Platforms Ⅰ and Ⅱ are steel structures located in offshore areas southeast of the Zhujiang(Pearl) River Delta, the northern South China Sea, in about 110 m water depth. The jackets, with aluminum sacrificial anodes for cathodic protection (CP) of the immersed zone, were launched in March 1995. In May 1996 a CP survey showed that, after almost one year of service, a low polarization level had been achieved and some extended unprotected zones existed, mainly in the deepest part of the Platform Ⅱ. Further to this, a joint activity was decided in order to assess the need of a possible retrofitting of the CP systems. The results of the activity carried out are dealt with, including technical and economical comparisons amongst several retrofitting options, both with sacrificial anodes and with impressed current systems. The adopted solution is illustrated and data are reported on the level of protection presently achieved.

  5. The Northern Sea Routes and Korea's Trade with Europe: Implications for Korea's Shipping Industry

    Directory of Open Access Journals (Sweden)

    Yeong-Seok Ha

    2014-12-01

    Full Text Available Melting Arctic waters have brought about global opportunities and challenges. One distinctive opportunity presented by the increasingly ice-free Arctic Ocean is its availability for shipping cargos between Europe and Asia. In adopting highly simplified assumptions of the Northern Sea Route (NSR being navigable and economical enough for shipping and NSR completely substituting for the incumbent Suez Canal route, this paper analyzes the maximum number of voyages possible for the transshipment of container cargo throughput for Korea's trade with Europe, particularly with Europe-17 and Europe-7. Our analysis shows the number of voyages range from over 2,900 to as little as 237 for Europe-17, depending on vessel sizes, when NSR is available for the whole year. With NSR opening for three months, the corresponding figures vary between 727 and 60 for Europe-17, and the figures for Europe-7 are between 2,725 and 222 and 682 and 56 voyages, respectively.

  6. Methylmercury in the Gulf of Trieste (Northern Adriatic Sea: From Microbial Sources to Seafood Consumers

    Directory of Open Access Journals (Sweden)

    Mark E. Hines

    2014-01-01

    Full Text Available The Gulf of Trieste (northern Adriatic Sea is one of the most mercury-polluted areas in the Mediterranean and in the world due to the past mining activity in the Idrija region (western Slovenia. The link between microbial production of toxic methylmercury (MeHg, and its bioaccumulation and biomagnification in marine food webs of the gulf is at present rather poorly characterized but is critical to understanding the links between sources and higher trophic levels, such as fish, that are ultimately vectors of human and wildlife exposure. This overview explores three major topics: (i the microbial biogeochemical cycling of Hg in the area, (ii the trophic transfer and bioaccumulation of MeHg in pelagic and benthic marine food webs, and (iii human exposure to Hg through marine fish and shellfish consumption. These are important goals since the Gulf of Trieste is an area of great economical importance.

  7. Grain size analysis of sediments from the northern Andaman Sea: Comparison of laser diffraction and sieve-pipette techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Rao, P.S.

    measured with laser diffraction show that 99% of the particles have an upper size range between 4.8 and 7.7 mu m. A calibration relationship between pipette and laser diffraction techniques has been developed for the northern Andaman Sea. A clay particle...

  8. The Kumamoto oyster Crassostrea sikamea is neither rare nor threatened by hybridization in the northern Ariake Sea, Japan

    Science.gov (United States)

    The status of the Kumamoto oyster Crassostrea sikamea in its native Japan is uncertain because of a lack of information about its abundance and distribution and a suggestion that C. sikamea and the Pacific oyster C. gigas hybridize in the northern Ariake Sea. Furthermore, broodstock populations on ...

  9. Responses of marine phytoplankton in iron enrichment experiments in the northern North Sea and northeast Atlantic Ocean

    NARCIS (Netherlands)

    Timmermans, Klaas R.; Gledhill, Martha; Nolting, Rob F.; Veldhuis, Marcel J.W.; Baar, Hein J.W. de; Berg, Constant M.G. van den

    1998-01-01

    Short-term iron enrichment experiments were carried out with samples collected in areas with different phytoplankton activity in the northern North Sea and northeast Atlantic Ocean in the summer of 1993. The research area was dominated by high numbers of pico-phytoplankton, up to 70,000 ml−1. Maximu

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  11. Variation in downwelling diffuse attenuation coefficient in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The diffuse attenuation coefficient for downwelling irradiance (Kd(λ)) is an important parameter for ocean studies. Based on the optical profile data measured during three cruises in the northern South China Sea in autumn from 2003 to 2005, variations in the Kd(λ) spectra were analyzed. The variability of Kd(λ) shows much distinct features in both magnitude and spectra pattern, it is much higher in coastal waters than that of open oceanic waters; and the blue-to-green (443/555) ratio of Kd(λ) tends to increase with chlorophyll a concentration ([Chl-a]) from open ocean to coastal waters. These characteristics can be explained most by the increase of aw+p(443)/aw+p(555) with [Chl-a]. In short waveband, the relation between Kd(λ)-Kw(λ) and [Chl-a] can be well described by a power law function, indicating the large contribution of phytoplankton to the variations in Kd(λ). As for the spectral model of the diffuse attenuation coefficient, there are good linear relationships between Kd(490) and Kd(λ) in other wavelengths with own slope and intercept of a linear functions in the spectral range 412-555 nm. Kd(490) is well correlated with the spectral ratio of remote sensing reflectance; and should enough measurement data are given, this empirical algorithm would be used in the Kd(λ) retrieval from ocean color satellite data. The variation in Kd(λ) provides much useful information for us to study the bio-optical property in the northern South China Sea.

  12. Ra-226 and Pb-210/Ra-226 Activity Ratio in the Northern South China Sea

    Science.gov (United States)

    Chi-Ju, L.; Yu-Chia, C.; Tsung-En, W.

    2004-05-01

    The surface water distributions and vertical profiles of Ra-226 in the northern South China Sea (SCS) have been measured. Surface water Ra-226 varies between 10 and 16 dpm/100 kg with higher values at stations adjacent to the landmass. Each Ra-226 profile shows an increase from the surface toward the bottom. Above 1000m depth Ra-226 is systematically about 5 dpm/100kg higher in the northern South China Sea than in the western North Pacific. This difference may be attributed to a strong Ra-226 source from the shelf and slope area of the SCS. Below this depth Ra-226 displays large variation within some of the profiles with lower limits being comparable to the activities of the western North Pacific but higher limits being systematically about 5 dpm/100kg higher. These high Ra-226 activities may reflect effects of the longer isolation time for the deep water in the SCS basin and strong Ra input from the underlying sediments. The Pb-210/Ra-226 activity ratio ranges between 1.4 and 2.7 in the surface water with higher activity ratio at the station closer to the Luzon Strait. The Pb-210 in excess over Ra-226 in the surface water due to atmospheric input may penetrate to a depth of about 200 to 500m. Below this depth, Pb-210/Ra-226 activity ratio ranges between 0.5 and 0.7 because Pb-210 is scavenged by settling particulates. Box model calculations within a mixed layer of 50m in the area yield a mean residence time of about 1 yr for Pb-210 if an atmospheric Pb-210 flux of 1 dpm/cm2/y is adopted. The activity ratio of about 0.5 to 0.7 in the deep water corresponds to a Pb-210 mean residence time of about 30 to 70 yrs with respect to particulate scavenging.

  13. Sub-seasonally resolved coral records of northern Red Sea - eastern Mediterranean climate during the Holocene and the last interglacial

    Science.gov (United States)

    Felis, T.; Rimbu, N.; Al-Rousan, S.; Kuhnert, H.; Lohmann, G.; Kölling, M.; Pätzold, J.

    2012-04-01

    The northern Red Sea represents a unique location where ocean currents transport warm tropical waters northward, enabling coral reef growth at unusually high latitudes of up to 29 °N. Moreover, one of the world's northernmost complexes of uplifted Pleistocene reef terraces can be found here at Aqaba (Jordan). We present sub-seasonally resolved reconstructions of surface ocean conditions in the northern Red Sea derived from annually banded Porites corals. The Sr/Ca and δ18O variations in the aragonitic skeletons of our modern and fossil coral colonies provide proxy records of temperature, salinity and hydrologic balance at the sea surface during the last centuries and during time windows (40 to 100 years length) of the Holocene and the last interglacial period. Previous work has shown that seasonality and interannual to decadal climate variability in the northern Red Sea as documented in our coral records is strongly coupled to climate variations in the eastern Mediterranean, Middle East and Europe, reflecting the prominent role of atmospheric teleconnections of the Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) in controlling regional climate on these timescales. New coral Sr/Ca data, in combination with δ18O, reveal an abrupt regime shift toward fresher surface ocean conditions in northern Red Sea surface waters at the end of the Little Ice Age. Possible mechanisms include a re-organization of the Northern Hemisphere atmospheric circulation. Sr/Ca records from a large number of fossil corals indicate a trend of decreasing temperature seasonality over the last 6000 years toward present-day. Such a trend is expected in the higher latitudes of the Northern Hemisphere from insolation changes on orbital timescales. Coral δ18O and Sr/Ca records suggest an increased seasonality in the hydrologic balance during time intervals around 4400, 4600 and 6000 years ago, which could result from both enhanced winter evaporation or increased summer precipitation

  14. Echinococcus granulosus Sensu Stricto in Dogs and Jackals from Caspian Sea Region, Northern Iran

    Directory of Open Access Journals (Sweden)

    Shirzad GHOLAMI

    2016-10-01

    Full Text Available Background: The aim of the present study was genotyping of Echinococcus granulosus isolates from dogs and jackals in Mazandaran Province, northern Iran, and using partial sequence of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1.Methods: E. granulosus isolates (n = 15 were collected from 42 stray dogs and 16 jackals found in south of the Caspian Sea in northern Iran. After morphological study, the isolates were genetically characterized using consensus sequences (366bp of the cox1 gene. Phylogenetic analysis of cox1 nucleotide sequence data was performed using a Bayesian Inference approach.Results: Four different sequences were observed among the isolates. Two genotypes [G1 (66.7% and G3 (33.3%] were identified among the isolates. The G1 sequences indicated three sequence profiles. One profile (Maz1 had 100% homology with reference sequence (AN: KP339045. Two other profiles, designated Maz2 and Maz3, had 99% homology with the G1 genotype (ANs: KP339046 and KP339047. A G3 sequence designated Maz4 showed 100% homology with a G3 reference sequence (AN: KP339048.Conclusion: The occurrence of the G1 genotype of E. granulosus sensu stricto as a frequent genotype in dogs is emphasized. This study established the first molecular characterization of E. granulosus in the province.

  15. Background current affects the internal wave structure of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Shuqun Cai; Xiaomin Long; Danpeng Dong; Shengan Wang

    2008-01-01

    The internal wave modal equations are solved with the consideration of background currents.Analytical and numerical solutions of some specific examples,including observations in the northern South China Sea(SCS),are obtained to investigate the effect of background current on internal wave vertical structure.The effects of current shear and curvature on intemal wave vertical structure are evaluated separately.It is found that the phase speed and wave structure are modified by background currents,the current shear has little effect on wave structure.whilst the current curvature Could have a strong impact on the wave structure.The extent of the effect by the current curvature on the wave structure depends on the magnitudes of current curvature,relative wave speed,and buoyancy frequency,sometimes the effect by the current curvature may even cause the wave to attenuate severely with depth.A new method to obtain the real eigenfunction with depth in the case that the waves become evanescent is also put forward.It is shown that the residual tidal current in the northern SCS is strong enough to cause the wave to attenuate severely at the upper layer.

  16. Species identification of mixed algal bloom in the Northern Arabian Sea using remote sensing techniques.

    Science.gov (United States)

    Dwivedi, R; Rafeeq, M; Smitha, B R; Padmakumar, K B; Thomas, Lathika Cicily; Sanjeevan, V N; Prakash, Prince; Raman, Mini

    2015-02-01

    Oceanic waters of the Northern Arabian Sea experience massive algal blooms during winter-spring (mid Feb-end Mar), which prevail for at least for 3 months covering the entire northern half of the basin from east to west. Ship cruises were conducted during winter-spring of 2001-2012 covering different stages of the bloom to study the biogeochemistry of the region. Phytoplankton analysis indicated the presence of green tides of dinoflagellate, Noctiluca scintillans (=N. miliaris), in the oceanic waters. Our observations indicated that diatoms are coupled and often co-exist with N. scintillans, making it a mixed-species ecosystem. In this paper, we describe an approach for detection of bloom-forming algae N. scintillans and its discrimination from diatoms using Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data in a mixed-species environment. In situ remote sensing reflectance spectra were generated using Satlantic™ hyperspectral radiometer for the bloom and non-bloom waters. Spectral shapes of the reflectance spectra for different water types were distinct, and the same were used for species identification. Scatter of points representing different phytoplankton classes on a derivative plot revealed four diverse clusters, viz. N. scintillans, diatoms, non-bloom oceanic, and non-bloom coastal waters. The criteria developed for species discrimination were implemented on MODIS data and validated using inputs from a recent ship cruise conducted in March 2013.

  17. Eutrophication in the northern Adriatic Sea: Pore water and sediment studies

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, D.E.; Berelson, W.M. (Univ. of Southern California, Los Angeles (United States)); Giordani, P.; Langone, L.; Frignani, M.; Ravaioli, M. (Inst. di Geologia Marina, CNR, Bologna (Italy))

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic (Po River being the largest) has increased nutrient input to this system and stimulated algal growth. Cores were collected for studies of pore water and solid phase chemistry at 6 stations in this region. [sup 210]Pb was used to constrain sediment accumulation rates and a range of 0-0.5 cm/yr was determined at different stations. Excess [sup 234]Th was only found in the upper 1-2 cm, suggesting that bioturbation is largely restricted to shallow depths. Pore water profiles show evidence of irrigation, and mean diffusive fluxes for oxygen, silica phosphate and ammonia are generally 20-90% of the fluxes obtained from benthic chamber measurements. This is consistent with previous work in this area in which studies of radon fluxes indicated that irrigation plays an important role in sediment-water exchange. Pore water profiles in the northern portion of the study area (near the Po River Delta) were markedly different than profiles in the south; sediments in the north are substantially more acidic and have high concentrations of dissolved iron and phosphate. From the alkalinity vs. TCO[sub 2] relationship in sediment pore waters it appears that differences in reactions involving the reduction of iron oxides and the exchange of magnesium for iron in clays are responsible for this regional difference in pore water properties. Sediments close to the Po apparently undergo more iron-magnesium exchange, while more distal sediments are limited in their ability to do so. Other pore water observations are limited in their ability to do so. Other pore water observations and trends regarding the shape of the silica profiles (which show shallow maxima) will be discussed.

  18. Deep crustal structure of Baiyun Sag, northern South China Sea revealed from deep seismic reflection profile

    Institute of Scientific and Technical Information of China (English)

    HUANG Chunju; ZHOU Di; SUN Zhen; CHEN Changmin; HAO Hujun

    2005-01-01

    This paper discusses deep crustal architecture of the Baiyun Sag of the Pearl River Mouth Basin, northern South China Sea based on velocity analysis, time-depth conversion and seismic interpretation of the deep seismic reflection profile DSRP-2002. The profile was acquired and processed to 14 S TWT by the China National Offshore Oil Corp. (CNOOC) in 2002. It extends across the Baiyun Sag of the Pearl River Mouth Basin, from the northern continental shelf of the SCS to the deepwater province. As the first deep seismic reflection profile in the Pearl River Mouth Basin,this profile reveals seismic phases from basement down to upper most mantle. The Moho surface appears in the profile as an undulating layer of varying thickness of 1-3 km. It is not a single reflector interface, but a velocity gradient or intercon- version layer. The crust thins stepwisely from the shelf to the continental slope and the abyssal plain (from north to south), and also thins under depocenters. The crustal thickness is only 7 km in the depocenter of the main Baiyun Sag, which corresponds to a Moho upwelling mirroring the basement topography. In the lower slope and the ocean-continental transition zone of the southernmost portion of the profile, three sub-parallel, NW-dipping strong reflectors found at depths around 10-21 km are interpreted as indications of a subducted Mesozoic oceanic crust. Crustal faults exist in the northern and southern boundaries of the Baiyun Sag. The intense and persistent subsidence of the Baiyun Sag might be related to the long-term activity of the crustal faults.

  19. Northern North Atlantic Sea Surface Height and Ocean Heat Content Variability

    Science.gov (United States)

    Hakkinen, Sirpa; Rhines, Peter; Worthen, Denise L.

    2013-01-01

    The evolution of nearly 20 years of altimetric sea surface height (SSH) is investigated to understand its association with decadal to multidecadal variability of the North Atlantic heat content. Altimetric SSH is dominated by an increase of about 14 cm in the Labrador and Irminger seas from 1993 to 2011, while the opposite has occurred over the Gulf Stream region over the same time period. During the altimeter period the observed 0-700 m ocean heat content (OHC) in the subpolar gyre mirrors the increased SSH by its dominantly positive trend. Over a longer period, 1955-2011, fluctuations in the subpolar OHC reflect Atlantic multidecadal variability (AMV) and can be attributed to advection driven by the wind stress ''gyre mode'' bringing more subtropical waters into the subpolar gyre. The extended subpolar warming evident in SSH and OHC during the altimeter period represents transition of the AMV from cold to warm phase. In addition to the dominant trend, the first empirical orthogonal function SSH time series shows an abrupt change 2009-2010 reaching a new minimum in 2010. The change coincides with the change in the meridional overturning circulation at 26.5N as observed by the RAPID (Rapid Climate Change) project, and with extreme behavior of the wind stress gyre mode and of atmospheric blocking. While the general relationship between northern warming and Atlantic meridional overturning circulation (AMOC) volume transport remains undetermined, the meridional heat and salt transport carried by AMOC's arteries are rich with decade-to-century timescale variability.

  20. Transit navigation through Northern Sea Route from satellite data and CMIP5 simulations

    Science.gov (United States)

    Khon, Vyacheslav C.; Mokhov, Igor I.; Semenov, Vladimir A.

    2017-02-01

    Rapid Arctic sea ice decline over the last few decades opens new perspectives for Arctic marine navigation. Further warming in the Arctic will promote the Northern Sea Route (NSR) as an alternative to the conventional Suez or Panama Canal routes for intercontinental shipping. Here we use both satellite data and CMIP5 ensemble of climate models to estimate the NSR transit window allowing intercontinental navigation between Atlantic and Pacific regions. To this end, we introduce a novel approach to calculate start and end dates of the navigation season along the NSR. We show that modern climate models are able to reproduce the mean time of the NSR transit window and its trend over the last few decades. The selected models demonstrate that the rate of increase of the NSR navigation season will slow down over the next few decades with the RCP4.5 scenario. By the end of the 21st century ensemble-mean estimates show an increase of the NSR transit window by about 4 and 6.5 months according to RCP4.5 and 8.5, respectively. Estimated trends for the end date of the navigation season are found to be stronger compared to those for the start date.

  1. Physical control of interannual variations of the winter chlorophyll bloom in the northern Arabian Sea

    Directory of Open Access Journals (Sweden)

    M. G. Keerthi

    2017-08-01

    Full Text Available The northern Arabian Sea hosts a winter chlorophyll bloom, triggered by convective overturning in response to cold and dry northeasterly monsoon winds. Previous studies of interannual variations of this bloom only relied on a couple of years of data and reached no consensus on the associated processes. The current study aims at identifying these processes using both  ∼  10 years of observations (including remotely sensed chlorophyll data and physical parameters derived from Argo data and a 20-year-long coupled biophysical ocean model simulation. Despite discrepancies in the estimated bloom amplitude, the six different remotely sensed chlorophyll products analysed in this study display a good phase agreement at seasonal and interannual timescales. The model and observations both indicate that the interannual winter bloom fluctuations are strongly tied to interannual mixed layer depth anomalies ( ∼  0.6 to 0.7 correlation, which are themselves controlled by the net heat flux at the air–sea interface. Our modelling results suggest that the mixed layer depth control of the bloom amplitude ensues from the modulation of nutrient entrainment into the euphotic layer. In contrast, the model and observations both display insignificant correlations between the bloom amplitude and thermocline depth, which precludes a control of the bloom amplitude by daily dilution down to the thermocline depth, as suggested in a previous study.

  2. Seabed litter composition, distribution and sources in the Northern and Central Adriatic Sea (Mediterranean).

    Science.gov (United States)

    Pasquini, Giulia; Ronchi, Francesca; Strafella, Pierluigi; Scarcella, Giuseppe; Fortibuoni, Tomaso

    2016-12-01

    Detecting the origin of marine benthic litter is fundamental for developing policies aimed at achieving the Good Environmental Status in European Seas by 2020, as requested by the Marine Strategy Framework Directive (MSFD). The abundance and composition of benthic litter in the Northern and Central Adriatic Sea were investigated at 67 stations with bottom trawl nets. Average density of benthic litter was 913±80items/km(2), ranking the Adriatic as one of the most polluted basins worldwide. Plastic was dominant in terms of numbers (80%) and weight (62%), and mainly consisted in bags, sheets and mussel nets. Higher quantities of litter were found in coastal areas, especially in front river mouths, coastal cities and mussel farms. In deep waters, litter hotspots were associated with most congested shipping lanes, indicating an additional litter input to the basin. Benthic litter composition resulted to be largely driven by the vicinity to local sources, i.e. mussel farming installations and most congested shipping routes. These findings provide useful insights to set measures to manage marine litter in the Adriatic region, and possibly to minimize this anthropogenic pollution.

  3. Dissolved lipid production in the Northern Adriatic (Mediterranean) in response to sea surface warmin

    Science.gov (United States)

    Gasparovic, Blazenka; Novak, Tihana; Godrijan, Jelena; Mlakar, Marina; MAric, Daniela; Djakovac, Tamara

    2017-04-01

    Marine dissolved organic matter (OM) represents one of the largest active pools of organic carbon in the global carbon cycle. Oceans and seas are responsible for half of global primary production. Ocean warming caused by climate change is already starting to impact the marine life that necessary will have impact on ocean productivity. The partition of OM production by phytoplankton (major OM producer in seas and ocens) in the conditions of rising temperatures may considerably change. This has implications for the export of organic matter from the photic zone. In this study, we set out to see how annual temperature changes between 10 and 30 C in the Northern Adriatic (Mediterranean) affect production of DOM and particularly dissolved lipids and lipid classes. We have sampled at two stations being oligotrophic and mesotrophic where we expected different system reaction to temperature changes. In addition, we performed microcosm incubations covering temperature range of the NA with nutrient amendments to test whether changes in the available nutrients would reflect those of dissolved OM in the NA. We have selected to work with extracellular OM produced during growth of diatom Chaetoceros curvisetus cultures according to the criteria that genera Chaetoceros are important component of the phytoplankton in the NA and are often among bloom-forming taxa. Details on the dissolved lipid and lipid classes production as plankton responce to rising temperature will be discussed.

  4. The Northern end of the Dead Sea Basin: Geometry from reflection seismic evidence

    Science.gov (United States)

    Al-Zoubi, A. S.; Heinrichs, T.; Qabbani, I.; ten Brink, U.S.

    2007-01-01

    Recently released reflection seismic lines from the Eastern side of the Jordan River north of the Dead Sea were interpreted by using borehole data and incorporated with the previously published seismic lines of the eastern side of the Jordan River. For the first time, the lines from the eastern side of the Jordan River were combined with the published reflection seismic lines from the western side of the Jordan River. In the complete cross sections, the inner deep basin is strongly asymmetric toward the Jericho Fault supporting the interpretation of this segment of the fault as the long-lived and presently active part of the Dead Sea Transform. There is no indication for a shift of the depocenter toward a hypothetical eastern major fault with time, as recently suggested. Rather, the north-eastern margin of the deep basin takes the form of a large flexure, modestly faulted. In the N-S-section along its depocenter, the floor of the basin at its northern end appears to deepen continuously by roughly 0.5??km over 10??km distance, without evidence of a transverse fault. The asymmetric and gently-dipping shape of the basin can be explained by models in which the basin is located outside the area of overlap between en-echelon strike-slip faults. ?? 2007 Elsevier B.V. All rights reserved.

  5. Microbial diversity in cold seep sediments from the northern South China Sea

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2012-05-01

    Full Text Available South China Sea (SCS is the largest Western Pacific marginal sea. However, microbial studies have never been performed in the cold seep sediments in the SCS. In 2004, “SONNE” 177 cruise found two cold seep areas with different water depth in the northern SCS. Haiyang 4 area, where the water depth is around 3000 m, has already been confirmed for active seeping on the seafloor, such as microbial mats, authigenic carbonate crusts and bivalves. We investigated microbial abundance and diversity in a 5.55-m sediment core collected from this cold seep area. An integrated approach was employed including geochemistry and 16S rRNA gene phylogenetic analyses. Here, we show that microbial abundance and diversity along with geochemistry profiles of the sediment core revealed a coupled reaction between sulphate reduction and methane oxidation. Acridine orange direct count results showed that microbial abundance ranges from 105 to 106 cells/g sediment (wet weight. The depth-related variation of the abundance showed the same trend as the methane concentration profile. Phylogenetic analysis indicated the presence of sulphate-reducing bacteria and anaerobic methane-oxidizing archaea. The diversity was much higher at the surface, but decreased sharply with depth in response to changes in the geochemical conditions of the sediments, such as methane, sulphate concentration and total organic carbon. Marine Benthic Group B, Chloroflexi and JS1 were predominant phylotypes of the archaeal and bacterial libraries, respectively.

  6. The Alcyonacea (soft corals and sea fans of Antsiranana Bay, northern Madagascar

    Directory of Open Access Journals (Sweden)

    Alison J. Evans

    2011-06-01

    Full Text Available During the past two decades, the Alcyonacea (soft corals and sea fans of the western Indian Ocean have been the subject of numerous studies investigating their ecology and distribution. Comparatively, Madagascar remains understudied. This article provides the first record of the distribution of Alcyonacea on the shallow fringing reefs around Antsiranana Bay, northern Madagascar. Alcyonacea accounted for between one and 16 % of the reef benthos surveyed; 11 genera belonging to four families, and several unidentified gorgonians (sea fans were recorded. Abundant and diverse Alcyonacea assemblages were recorded on reefs that were exposed with high water clarity. However, abundant and diverse communities were also observed on sheltered reefs with low water clarity, high sediment cover and relatively low hard coral cover, implying potential competitive advantage under these conditions. Where prevailing environmental conditions were relatively moderate, the Alcyonacea assemblages were generally characterised by low diversity and an abundance of Sinularia and Sarcophyton. Because of the current lack of knowledge about the coral reefs in Antsiranana Bay, it was not possible to suggest any appropriate management actions. We propose that this account should be built upon with similar studies of other reef taxa. This series would address the paucity of published information from this part of the western Indian Ocean, and would provide the baseline information necessary to inform future management plans for the area.

  7. Community composition, abundance and biomass of zooplankton in Zhangzi Island waters, Northern Yellow Sea

    Science.gov (United States)

    Yin, Jiehui; Zhang, Guangtao; Li, Chaolun; Wang, Shiwei; Zhao, Zengxia; Wan, Aiyong

    2017-09-01

    Samples were collected monthly from the sea area around Zhangzi Island, northern Yellow Sea, from July 2009 to June 2010. Vertical net towing was used to examine spatial and temporal variability in zooplankton abundance and biomass. Overall, Calanus sinicus and Saggita crassa were the dominant species found during the study period, while the amphipod Themisto gracilipes was dominant in winter and spring. Vast numbers of the ctenophore species of the genus Beroe were found in October and November. It was not possible to count them, but they constituted a large portion of the total zooplankton biomass. Zooplankton species diversity was highest in October, and species evenness was highest in April. Zooplankton abundance (non-jellyfish) and biomass were highest in June and lowest in August, with annual averages of 131.3 ind./m³ and 217.5 mg/m³, respectively. Water temperature may be responsible for the variations in zooplankton abundance and biomass. Beroe biomass was negatively correlated with other zooplankton abundance. Longterm investigations will be carried out to learn more about the influence of the environment on zooplankton assemblages.

  8. Widespread methane leakage from the sea floor on the northern US Atlantic margin

    Science.gov (United States)

    Skarke, Adam; Ruppel, Carolyn; Kodis, Mali'o; Brothers, Daniel S.; Lobecker, Elizabeth A.

    2014-01-01

    Methane emissions from the sea floor affect methane inputs into the atmosphere, ocean acidification and de-oxygenation, the distribution of chemosynthetic communities and energy resources. Global methane flux from seabed cold seeps has only been estimated for continental shelves, at 8 to 65 Tg CH4 yr−1, yet other parts of marine continental margins are also emitting methane. The US Atlantic margin has not been considered an area of widespread seepage, with only three methane seeps recognized seaward of the shelf break. However, massive upper-slope seepage related to gas hydrate degradation has been predicted for the southern part of this margin, even though this process has previously only been recognized in the Arctic. Here we use multibeam water-column backscatter data that cover 94,000 km2 of sea floor to identify about 570 gas plumes at water depths between 50 and 1,700 m between Cape Hatteras and Georges Bank on the northern US Atlantic passive margin. About 440 seeps originate at water depths that bracket the updip limit for methane hydrate stability. Contemporary upper-slope seepage there may be triggered by ongoing warming of intermediate waters, but authigenic carbonates observed imply that emissions have continued for more than 1,000 years at some seeps. Extrapolating the upper-slope seep density on this margin to the global passive margin system, we suggest that tens of thousands of seeps could be discoverable.

  9. THE N/P RATIO IN THE NORTHERN SOUTH YELLOW SEA IN AUTUMN

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Study of horizontal and vertical distributions of the N/P (nitrogen v ersus phosphate) atom ratio in the northern South Yellow Sea showed that the ratio varied greatly in u pper waters of the investigated area and was always much greater than the theoretical Redfield rat io of 16:1 found below the thermocline zone. It was in general higher near the coast and lower in the centr al part. With increasing depth, the ratio became smaller and smaller. This distribution pattern is attrib uted to: 1) the anthropogenic influence of the surface N and P which makes the N/P ratio differ from the norma l value; 2) the easy adsorption of P on particles hinders P transport to the central part; 3) below t he thermocline zone, the N and P mainly come from the remineralization of the sedimented phytoplankton residues which have almost the theoretical Redfield value and; 4) the existence of the Yellow Sea Bottom Cold W ater which inhibits the vertical exchange of the water.

  10. An operational coupled wave-current forecasting system for the northern Adriatic Sea

    Science.gov (United States)

    Russo, A.; Coluccelli, A.; Deserti, M.; Valentini, A.; Benetazzo, A.; Carniel, S.

    2012-04-01

    Since 2005 an Adriatic implementation of the Regional Ocean Modeling System (AdriaROMS) is being producing operational short-term forecasts (72 hours) of some hydrodynamic properties (currents, sea level, temperature, salinity) of the Adriatic Sea at 2 km horizontal resolution and 20 vertical s-levels, on a daily basis. The main objective of AdriaROMS, which is managed by the Hydro-Meteo-Clima Service (SIMC) of ARPA Emilia Romagna, is to provide useful products for civil protection purposes (sea level forecasts, outputs to run other forecasting models as for saline wedge, oil spills and coastal erosion). In order to improve the forecasts in the coastal area, where most of the attention is focused, a higher resolution model (0.5 km, again with 20 vertical s-levels) has been implemented for the northern Adriatic domain. The new implementation is based on the Coupled-Ocean-Atmosphere-Wave-Sediment Transport Modeling System (COAWST)and adopts ROMS for the hydrodynamic and Simulating WAve Nearshore (SWAN) for the wave module, respectively. Air-sea fluxes are computed using forecasts produced by the COSMO-I7 operational atmospheric model. At the open boundary of the high resolution model, temperature, salinity and velocity fields are provided by AdriaROMS while the wave characteristics are provided by an operational SWAN implementation (also managed by SIMC). Main tidal components are imposed as well, derived from a tidal model. Work in progress is oriented now on the validation of model results by means of extensive comparisons with acquired hydrographic measurements (such as CTDs or XBTs from sea-truth campaigns), currents and waves acquired at observational sites (including those of SIMC, CNR-ISMAR network and its oceanographic tower, located off the Venice littoral) and satellite-derived wave-heights data. Preliminary results on the forecast waves denote how, especially during intense storms, the effect of coupling can lead to significant variations in the wave

  11. Diversity of Picoeukaryotes at an Oligotrophic Site off the Northern Red Sea Coast

    KAUST Repository

    Espinosa, Francisco Jose Acosta

    2012-05-01

    Picoeukaryotes are protist 3 µm belonging to a wide diversity of taxonomic groups, and they are an important constituent of the ocean microbiota, performing essential ecological roles in marine trophic chains and in nutrient and carbon budgets. Despite this, the true extent of their diversity is currently unknown, and in the last decade molecular surveys have uncovered a substantial number of previously unknown groups from all taxonomic levels. No studies on this group have been done so far on the Red Sea, a unique marine environment characterized by oligotrophic conditions and high irradiance, salinity and water temperature. We sampled the surface waters of a site near the northern Red Sea coast, and analyzed the picoeukaryotic diversity through the construction of PCR clone libraries using the 18S ribosomal gene. The community captured by our library is dominated by three main groups, the alveolates (32%), chlorophytes (32%) and Stramenopiles (20.55%). Members of Radiolaria, Cercozoans and Haptophyta were also found, although in low abundances. Photosynthetic organisms are especially diverse and abundant in the sample, with heterotrophic organism mostly composed by the mostly parasitic novel alveolates and bacterivorous stramenopiles. Novel clades were detected among the Novel Alveolates- II and the photosynthetic stramenopiles taxa, which suggests that they may be part of a number of groups unique to the basin and adapted to the high salinity and temperature conditions. This is the first study done on the Red Sea focusing on the diversity of the complete picoeukaryotic fraction, and provides a stepping stone in the characterization of the picoeukaryotic component of the microbial diversity of the basin.

  12. The South China Sea Arbitration Case:A Public Opinion War Waged by U.S. & Philippines%南海仲裁案:美菲联手打舆论战

    Institute of Scientific and Technical Information of China (English)

    李金明

    2016-01-01

    南海仲裁案从表面看是菲律宾向仲裁庭提交的,但真正的幕后推手是美国。美国将之作为制衡中国的一步妙棋,妄图以此来化解中国对南海的主权要求。我们从2015年7月8日至13日仲裁庭举行的第一轮口头辩论中就可以看出,美国才是这场仲裁案的主角,无论从文件起草,还是法庭辩论,都是由华盛顿律师一手代理。美菲为了使南海仲裁案引起国际上的重视,还广泛制造舆论,极力渲染南海的紧张气氛,将南海问题说成是全球关注的焦点,藉此向仲裁庭施压。菲律宾大法官甚至以“扩充军备竞赛”为由,对仲裁庭进行威胁和恫吓。然而,由于领土主权问题不属于该仲裁庭的管辖范围,即使仲裁庭未来做出裁决,南海领土争议问题依然存在,最终还是要通过当事国双方直接谈判来解决。%The South China Sea Arbitration case has been superficially submitted by the Philippines to the arbitrationtribunal,but the the real driving force behind it is the United States,who has regarded it as a wise move to counterbalance China and to try to defuse China's sovereignty claims in the South China Sea. From the first round of the oral argument held by the Arbitral Tribunal from July 8th to 13 th ,2015,one can sense that the U.S.is the protagonist of the arbitration.Both the drafting of the legal documents and the tri-bunal arguments were single-handedly agented by the Washington lawyers.In order to bring the South Chi-na Sea Arbitration to the forefront of the international attention,the U.S.and the Philippines had created widespread public opinion,played up tensions in the South China Sea,and called the South China Sea is-sue the focus of global attention,by which means they attempted to put pressure on the Arbitral Tribunal. The Philippine justice even threatened and intimated the Arbitral Tribunal on the pretext of arms race exten-sion.However,the territorial

  13. Performance analysis of coupled and uncoupled hydrodynamic and wave models in the northern Adriatic Sea

    Science.gov (United States)

    Busca, Claudia; Coluccelli, Alessandro; Valentini, Andrea; Benetazzo, Alvise; Bonaldo, Davide; Bortoluzzi, Giovanni; Carniel, Sandro; Falcieri, Francesco; Paccagnella, Tiziana; Ravaioli, Mariangela; Riminucci, Francesco; Sclavo, Mauro; Russo, Aniello

    2014-05-01

    The complex dynamics of the Adriatic Sea are the result of geographical position, orography and bathymetry, as well as rivers discharge and meteorological conditions that influence, more strongly, the shallow northern part. Such complexity requires a constant monitoring of marine conditions in order to support several activities (marine resources management, naval operations, emergency management, shipping, tourism, as well as scientific ones). Platforms, buoys and mooring located in Adriatic Sea supply almost continuously real time punctual information, which can be spatially extended, with some limitations, by drifters and remote sensing. Operational forecasting systems represent valid tools to provide a complete tridimensional coverage of the area, with a high spatial and temporal resolution. The Hydro-Meteo-Clima Service of the Emilia-Romagna Environmental Agency (ARPA-SIMC, Bologna, Italy) and the Dept. of Life and Environmental Sciences of Università Politecnica delle Marche (DISVA-UNIVPM, Ancona, Italy), in collaboration with the Institute of Marine Science of the National Research Council (ISMAR-CNR, Italy) operationally run several wave and hydrodynamic models on the Adriatic Sea. The main implementations are based on the Regional Ocean Modeling System (ROMS), the wave model Simulating WAves Nearshore (SWAN), and the coupling of the former two models in the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) system. Horizontal resolutions of the different systems range from the 2 km of AdriaROMS to the 0.5 km of the recently implemented northern Adriatic COAWST. Forecasts are produced every day for the subsequent 72 hour with hourly resolution. All the systems compute the fluxes exchanged through the interface with the atmosphere from the numerical weather prediction system named COSMO-I7, an implementation for Italy of the Consortium for Small-scale Modeling (COSMO) model, at 7 km horizontal resolution. Considering the several operational

  14. Structural framework of the Gulf of Elat (AQABA), Northern Red Sea

    Science.gov (United States)

    Ben-Avraham, Zvi

    1985-01-01

    The Gulf of Elat (Aqaba) occupies the southern part of the Dead Sea rift. The rift is considered to be a plate boundary of the transform type (partially leaky) which connects seafloor spreading in the Red Sea with the Sagros-Taurus zone of continental collision. The deep water in the Gulf of Elat, up to 1850 m, provides a rare opportunity to examine the process of continental rifting by marine geophysical techniques. The bathymetry alone provides much information about fault patterns in this area. The fragmentation of the once continuous Arabian-African platform is a complicated process. It shapes the structure of the gulf which has developed through continuing tectonism, primarily consisting of faulting. Recent geophysical and geological studies of the Gulf of Elat including bathymetry, bottom photographs, continuous seismic profiles, seismic refraction, gravity, magnetics, heat flow, and coring provide new information about the shallow and deep crustal structure of this important segment of the world rift system. The shallow structure of the gulf is dominated by three elongated en echelon basins, which strike N20°-25°E. Undulations in the floors of the basins produce several distinct deeps. These basins are interpreted as pullaparts. The new data from the gulf suggest that classical models for the formation of these structures should be modified. Only one of the longitudinal faults of each depression is a strike-slip fault, while the other is predominantly a normal fault. The situation with the other two sides of the basin which are supposed to be composed of normal faults may also be more complex than previously thought. At least in one case, one such boundary is composed of a strike-slip fault while the other has no significant fault. Crustal models of the Gulf of Elat based on gravity data indicate that the basins are rather shallow and do not extend into the lower crust. The fill of the basins extends to about 5 km below the seafloor in. the northern and

  15. Geochemical characteristics of amphibole in the gabbroic rocks of the medial area of the Godzilla Megamullion, Parece Vela Basin, Philippine Sea

    Science.gov (United States)

    Harigane, Y.; Morishita, T.; Snow, J. E.; Tamura, A.; Michibayashi, K.; Ohara, Y.; Arai, S.

    2011-12-01

    The oceanic core complexes (OCCs) are found on most slow spreading ridges proposed by Escartin et al. (2008), which has been suggested that OCC along a spreading axis represent the megamullion in morphological structure and the oceanic detachment fault in formation process by analogy of continental metamorphic core complex. The Godzilla Megamullion (GM), the largest OCC in the world, is located at the extinct Parece Vela Basin spreading ridge in the Philippine Sea (Ohara et al., 2001). Fault rocks are common on the surface of the GM, indicating the presence of a detachment fault exposed on the seafloor (Harigane et al., 2011). Harigane et al. (2008) reported that the hydrothermal metamorphism occurred retrogressively at the gabbroic rocks during the deformation related to the detachment fault. However, the origins of fluids and the fluid-rock interaction during deformation for the detachment fault are still unsolved. In this study, we present trace element geochemical analyses of amphibole and clinopyroxene of the gabbroic rocks sampled from the medial area of the GM using LA-ICP-MS at Kanazawa University and University of Houston. Most of the gabbroic rocks show a porphyroclastic texture that consist of plagioclase/clinopyroxene porphyroclasts and a fine-grained plagioclase/clinopyroxene/amphibole matrix. The amphibole compositions consist of pargasite and magnesio-hornblende (i.e. brown hornblende) with minor actinolite (i.e. green hornblende). These brown hornblendes have two distinct types in microstructure: bleb type and rim type. The bleb type occurs in the cores of clinopyroxene porphyroclasts and has no evidence of deformation. The rim type occurs as fine grains at the rim of clinopyroxene porphyroclasts. All green hornblende grains show no evidence of deformation and occur at the rim of brown hornblende and clinopyroxene grains. All chondrite-normalized REE patterns of clinopyroxene in the gabbroic rocks are characterized by flat heavy-REE and light

  16. 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

  17. First Cassini Radio Science Bistatic Scattering Observation of Titan's Northern Seas

    Science.gov (United States)

    Marouf, E. A.; Kliore, A. J.; Rappaport, N. J.; French, R. G.; Schinder, P. J.; Anabtawi, A.; Wong, K. K.; Armstrong, J. W.; Asmar, S. W.; Flasar, F. M.; Iess, L.; McGhee-French, C.; Nagy, A. F.; Tortora, P.; Barbinis, E.; Buccino, D.; Kahan, D. S.

    2014-12-01

    On May 17, 2014, the Cassini spacecraft completed its 101 flyby of Saturn's satellite Titan. Mirror-like (quasi-specular) reflections of radio signals transmitted by Cassini were observed on the Earth (bistatic scattering geometry). Three right circularly polarized (RCP) sinusoidal signals were transmitted (wavelength = 0.94, 3.6, and 13 cm). Both the RCP and LCP surface reflections were observed at the Canberra, Australia, complex of the NASA Deep Space Network. The signals probed the region extending from about (lat, long) = (79°N, 315°W) to about (74°N, 232°W). For the first time, two major Titan northern seas, the Ligeia Mare and the Kraken Mare, were probed. Clearly detectable RCP and LCP echo components were observed over both seas at all 3 wavelengths. The echoes were intermittent over the region in between the two seas. The echoes from the seas have narrowband spectra well modeled as pure sinusoids, suggesting very smooth surfaces over > ~1 cm scales. Over shorelines and river like channels the measured spectra reveal a second distinct broadband component, likely reflection from a rough bottom solid interface. Modeling the narrowband echo components as sinusoids, we estimate the RCP and LCP echo power profiles over the observation period. High resolution power profiles (several seconds time average; 0.2 to 2 km along the ground track) reveal remarkable structural detail. The statistical measurement uncertainty improves significantly when the resolution is degraded to about 1 m time average (3 to 30 km). Comparison of the 1 m power profiles with theoretical predictions computed assuming absent surface waves (negligible roughness) reveals excellent agreement with reflections from liquid hydrocarbons. The small statistical uncertainty promises to strongly constrain the liquid composition (ethane vs methane dominance). In principle, the measured RCP/LCP power ratio removes dependence on roughness and enables determination of the dielectric constant

  18. Organic Geochemical Characteristics of Time—Series Settling Particles in Northern SOuth China Sea and Their Implications

    Institute of Scientific and Technical Information of China (English)

    陈建芳; HOW-KINWONG; 等

    1998-01-01

    Organic carbon,total nitrogen,amino acids,sugars,and chlorophyll were deter mined in <1mm fractions of the samples collected by successive large aperture time-series sediment traps(Honjo-Mark VI) in northern South China Sea during September 1987 to October 1988,The ratio of C/N and the relative abundance of amino acids and sugars show that organic matter in the settling particles from northern South China Sea is derived mainly from marine plantkon(esecially phytoplankton),The organic carbon fluxes in our sediment traps are lower than those in other sediment traps.But the relative contents of Corg/total particulate matter are generally similar to those in the Panama Basin,Arabian Sea and Subarctic Pacific.It is suggested that monsoon-caused changes of physical and chemical conditions in the upper euphotic layer would control the fluxes of organic matter as well as its composition and transport in northern South China Sea.

  19. Detection of cyclonic eddy generated by looping tropical cyclone in the northern South China Sea:a case study

    Institute of Scientific and Technical Information of China (English)

    HU Jianyu; KAWAMURA Hiroshi

    2004-01-01

    A case study on the cyclonic eddy generated by the tropical cyclone looping over the northern South China Sea (NSCS) is presented, using TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature (SST) data.Three cases relating to the tropical cyclone events (Typhoon Kai-Tak in July 2000, Tropical Storm Russ in June 1994 and Tropical Storm Maria in August-September 2000) over the NSCS have been analyzed. For each looping tropical cyclone case, the cyclonic eddy with an obvious sea level depression appears in the sea area where the tropical cyclone takes a loop form, and lasts for about 2 weeks with a slight variation in location. The cold core with the SST difference greater than 2 ℃ against its surrounding areas is also observed by the satellite-derived SST data.

  20. Detection of cyclonic eddy generated by looping tropical cyclone in the northern South China Sea:a case study

    Institute of Scientific and Technical Information of China (English)

    HU Jianyu; KAWAMURA Hiroshi

    2004-01-01

    A case study on the cyclonic eddy generated by the tropical cyclone looping over the northern South China Sea (NSCS) is presented, using TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature (SST) data.Three cases relating to the tropical cyclone events (Typhoon Kai-Tak in July 2000, Tropical Storm Russ in June 1994and Tropical Storm Maria in August-September 2000) over the NSCS have been analyzed. For each looping tropical cyclone case, the cyclonic eddy with an obvious sea level depression appears in the sea area where the tropical cyclone takes a loop form, and lasts for about 2 weeks with a slight variation in location. The cold core with the SST difference greater than 2 ℃ against its surrounding areas is also observed by the satellite-derived SST data.

  1. Characteristics of Clay Minerals in the Northern South China Sea and Its Implications for Evolution of East Asian Monsoon since Miocene

    Institute of Scientific and Technical Information of China (English)

    Wan Shiming; Li Anchun; Xu Kehui; Yin Xueming

    2008-01-01

    Clay mineral assemblages, crystallinity, chemistry, and micromorphology of clay particles in sediments from ODP Site 1146 in the northern South China Sea (SCS) were analyzed, and used to trace sediment sources and obtain proxy records of the past changes in the East Asian monsoon climate since the Miocene, based on a multi-approach, including X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDS). Clay minerals consist mainly of illite and smectite, with associated chlorite and kaolinite. The illite at ODP Site 1146 has very well-to-well crystallinity, and smectite has moderate-to-poor crystallinity. In SEM the smectite particles at ODP Site 1146 often appear cauliflower-like, a typical micromorphology of volcanic smecites. The smectite at ODP Site 1146 is relatively rich in Si element, but poor in Fe, very similar to the smectite from the West Philippine Sea. In contrast, the chemical composition of illite at ODP Site 1146 has no obvious differences from those of the Loess plateau, Yellow River, Yangtze River, and Pearl River. A further study on sediment source indicates that smectite originates mainly from Luzon, kaolinite from the Pearl River, and illite and chlorite from the Pearl River, Taiwan and/or the Yangtze River. The clay mineral assemblages at ODP Site 1146 were not only controlled by continental eathering regimes surrounding the SCS, but also by the changing strength of the transport processes. The ratios of (illite+chlorite)/smectite at ODP Site 1146 were adopted as proxies for the East Asian monsoon evolution. Relatively higher ratios reflect strongly intensified winter monsoon relative to summer monsoon, in contrast, lower ratios indicate a strengthened summer monsoon relative to winter monsoon. The consistent variation of this clay proxy from those of Loess plateau, eolian deposition in the North Pacific, planktonic, benthic foraminifera, and black carbon in the SCS since 20 Ma shows

  2. Sea-level related resedimentation processes on the northern slope of Little Bahama Bank (Middle Pleistocene to Holocene)

    DEFF Research Database (Denmark)

    Lantzsch, H.; Roth, S.; Reijmer, J.J.G.

    2007-01-01

    Middle Pleistocene to Holocene sediment variations observed in a 26 metre long core taken during a cruise of the RV Marion Dufresne are presented. Core MD992202 was retrieved from the northern slope of Little Bahama Bank and provides an excellent example for sedimentation processes in a mid-slope....... These glacial to interglacial differences in mineralogy, grain-size distribution and organic content clearly show the impact of climatically controlled sea-level fluctuations on the sedimentation patterns of the northern slope of Little Bahama Bank. The coarser deposits (ii) occur mainly at the transitions from...

  3. Eutrophication in the northern Adriatic Sea: Benthic fluxes and nutrient budgets

    Energy Technology Data Exchange (ETDEWEB)

    Berelson, W.M.; Hammond, D.E. (Univ. of Southern California, Los Angeles (United States)); Giordani, P. (Inst. di Geologia Marina-CNR, Bologna (Italy))

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic has increased nutrient input to this system and stimulated algai growth. Five stations in the western Adriatic (south of the Po River Delta) were occupied during September, 1988 and benthic flux chambers used to measure nutrient fluxes. These sites included 3 stations previously studied in 1982. Flux measurements of dissolved silica, nitrate, oxygen, ammonia, phosphate, CO[sub 2], alkalinity and radon were made during 24 hour incubations of flux chambers (area covered - 0.07 m[sup 2], volume = [approximately]81) that were continuously stirred and sampled periodically. Nutrient fluxes measured were generally consistent with the fluxes measured previously in June, 1982 except for radon fluxes which were 203 times greater in the earlier field season. There was a general trend in nutrient fluxes to decrease offshore, a pattern probably controlled by the sedimentation patterns because fine grained, organic matter-rich sediment are concentrated in a zone near shore. Average regional fluxes were (in mmol m[sup -2]d[sup -1], negative values indicate flux into sediment): Oxygen (-12), CO[sub 2] (19), Alkalinity (4), Silica (3.3), Ammonia (1.5), Phosphate (0.1) and Nitrate (0.3). The carbon/ammonia flux ratio is about twice the C/N ratio in marine phytoplankton, suggesting that large amounts of denitrification may be occuring in these sediments. Comparisons of benthic fluxes and sediment burial rates indicate that 50-90% of the carbon, silica, phosphorus and nitrogen arriving at the sediment-water interface is recycled before burial. The nutrient input to the water column from NW Adriatic sediments is about equal to the input from coastal rivers.

  4. A propagation model for the internal solitary waves in the northern South China Sea

    Science.gov (United States)

    Cai, Shuqun; Xie, Jieshuo

    2010-12-01

    A two-dimensional, regularized long-wave equation model is developed to study the dynamic mechanisms of the propagation and evolution of the internal solitary waves (ISWs) in the northern South China Sea (SCS). It is shown that the bottom topography would cause the polarity reversal of ISWs, the change of the local wave crestline shape, and some diminution in wave amplitude; even if the ISWs are induced at the small sill channel along the Luzon Strait, they could propagate westward with their crestlines covering a large area in the latitudinal direction in the northern SCS. When there are two trains of ISWs propagating from the same source site with a time lag but different amplitudes of initial solitons, the latter train of ISWs with a larger amplitude may catch then swallow the former one with a smaller amplitude, and the wave amplitude of the merged ISW train decreases while the wave number increases. When there are two trains of ISWs propagating from the different source sites at the same time with the same amplitude of initial solitons, the crestlines of the two ISW trains may meet and a new leading soliton is induced at the connection point. Once the ISW trains collide with the island, before the island, a weak ISW train is reflected; behind the island, the former crestlines of the ISW train are torn by the island into two new trains, which may reconnect after passing around the island. The propagation direction, the wave amplitude, and the reconnection point of the new merged ISW train behind the island depend on the relative orientation of the original soliton source site to the island.

  5. Late Pliocene-Pleistocene environments and glacial history of the northern North Sea

    Science.gov (United States)

    Reinardy, Benedict T. I.; Hjelstuen, Berit O.; Sejrup, Hans Petter; Augedal, Hans; Jørstad, Arild

    2017-02-01

    Based on new geochronological (amino acids and Sr-isotopes) and lithological data combined with analyses of 3D seismic data, the Pliocene-Pleistocene development of the central northern North Sea has been investigated. At the start of the Plio-Pleistocene Transition the study area was dominated by a deltaic, shallow marine or tidal depositional environment with sediments mainly sourced from the west. These sand-rich sediments include green glauconitic grains that belong to the Utsira Sand with a local provenance. Directly above the base Quaternary (R2) a 60 m thick layer of mud-rich sediments of glacimarine origin were deposited at a rate of ∼12 cm/ka between ∼2-1.5 Ma and up to 80 cm/ka between 1.5 and 1.2 Ma possibly reflecting glacial ice advancing to the Norwegian coastline. The high rate of deposition in the Early Pleistocene occurred immediately before the initiation of the Norwegian Channel Ice Stream at ∼1.1 Ma. Following this, a large part of the sediment input from Fennoscandia seems to have been directed away from the study area to the shelf break. At the start of the Mid Pleistocene Transition (MPT), subaerial conditions allowed the formation of a >50 km long fluvial channel across the study area draining water from the east to the south west. The earliest evidence of grounded ice in the investigated area comes from mega scale glacial lineations formed during the MPT, at or just after ∼1.2 Ma. Following this, a regional unconformity (R4) was formed by one or more grounded ice advances across the study area possibly during or directly after the MPT and likely marks the boundary between the Early and Mid Pleistocene glacimarine sediments. The Mid to Late Pleistocene stratigraphy is dominated by glacimarine sediments and tills and is associated with multiple generations of tunnel valleys observed within the seismic data. A high shear strength till containing chalk clasts transported from the west and/or south of the study area was likely deposited

  6. Effects of changing sea ice on marine mammals and subsistence hunters in northern Alaska from traditional knowledge interviews.

    Science.gov (United States)

    Huntington, Henry P; Quakenbush, Lori T; Nelson, Mark

    2016-08-01

    Marine mammals are important sources of food for indigenous residents of northern Alaska. Changing sea ice patterns affect the animals themselves as well as access to them by hunters. Documenting the traditional knowledge of Iñupiaq and Yupik hunters concerning marine mammals and sea ice makes accessible a wide range of information relevant to understanding the ecosystem to which humans belong. We interviewed hunters in 11 coastal villages from the northern Bering Sea to the Beaufort Sea. Hunters reported extensive changes in sea ice and weather that have affected the timing of marine mammal migrations, their distribution and behaviour and the efficacy of certain hunting methods. Amidst these changes, however, hunters cited offsetting technological benefits, such as more powerful and fuel-efficient outboard engines. Other concerns included potential impacts to subsistence hunting from industrial activity such as shipping and oil and gas development. While hunters have been able to adjust to some changes, continued environmental changes and increased disturbance from human activity may further challenge their ability to acquire food in the future. There are indications, however, that innovation and flexibility provide sources of resilience.

  7. Prediction of Gravity Anomalies Over the South China and Philippine Seas from Multi-satellite Altimeter Sea Surface Heights%根据多卫星高度计海面高数据推算南中国海及菲律宾海域重力异常

    Institute of Scientific and Technical Information of China (English)

    Isaac Dadzie; 李建成; 褚永海

    2008-01-01

    Gravity anomalies on a 2.5×2.5 arc-minute grid in a non-tidal system were derived over the South China and Philippine Seas from multi-satellite altimetry data. North and east components of deflections of the vertical were computed from altimeter-derived sea surface heights at crossover locations, and gridded onto a 2.5×2.5 arc-minute resolution grid. EGM96-derived components of deflections of the vertical and gravity anomalies gridded into 2.5×2.5 arc-minute resolutions were then used as reference global geopotential model quantities in a remove-restore procedure to implement the Inverse Vening Meinesz formula via the 1D-FFT technique to predict the gravity anomalies over the South China and Philippine Seas from the gridded altimeter-derived Components of deflections of the vertical. Statistical comparisons between the altime-ter-derived and the shipboard gravity anomalies showed that there is a root-mean-square agreement of 5.7 mgals between them.

  8. The optical scattering property: spatial and angle variability in Northern South China Sea

    Science.gov (United States)

    Li, Cai; Cao, Wenxi; Yang, Yuezhong; Xu, Zhantang

    2015-02-01

    Observations are presented of the Volume scattering function (VSF) over the angular interval 20 to 160°, to maximum depth of about 90m in the Northern South China Sea in Case I and Case II waters. The observations were collected by using a self-developed in situ scattering instrument, which synchronously measured the attenuation coefficient, the VSFs in seven angles between 20 to 160° at 650nm, and the sea depths. General, the VSFs show a strong scattering in the forward, a broad scattering minimum in the scattering angular interval 90 to 126° and a weak increase in the rest of backward scattering angles. The analysis of the in situ data also indicates that the magnitude and the shape of the VSF change with areas and profile depths. From Case II to Case I, the forward scattering in 20°, which is mainly due to relatively large suspended particles, varied about three orders magnitude with highest values observed in Case II waters. In Case I waters, form the surface layer to the deeper layer, the magnitude of the VSFs firstly decreased with the depth, and then increased with the depth until reached a maximum scattering layer between 30 to 50m, and then decreased with depth until reached the maximum measurement depth. In Case II waters, the vertical profile distributions of VSF are complex, but in almost all profile, the magnitude of the VSFs firstly decreased with the depth, and then increased with the depth until reached the maximum measurement depth. The result of analysis also showed that in almost all of these stations, in the surface water, based on the light scattering by bubbles at shallow depths, the angle scattering at 60º-80º has a significant "shoulder", and the wind plays a key role in the bubble scattering.

  9. Observed wintertime tidal and subtidal currents over the continental shelf in the northern South China Sea

    Science.gov (United States)

    Li, Ruixiang; Chen, Changsheng; Xia, Huayong; Beardsley, Robert C.; Shi, Maochong; Lai, Zhigang; Lin, Huichan; Feng, Yanqing; Liu, Changjian; Xu, Qichun; Ding, Yang; Zhang, Yu

    2014-08-01

    Synthesis analyses were performed to examine characteristics of tidal and subtidal currents at eight mooring sites deployed over the northern South China Sea (NSCS) continental shelf in the 2006-2007 and 2009-2010 winters. Rotary spectra and harmonic analysis results showed that observed tidal currents in the NSCS were dominated by baroclinic diurnal tides with phases varying both vertically and horizontally. This feature was supported by the CC-FVCOM results, which demonstrated that the diurnal tidal flow over this shelf was characterized by baroclinic Kelvin waves with vertical phase differences varying in different flow zones. The northeasterly wind-induced southwestward flow prevailed over the NSCS shelf during winter, with episodic appearances of mesoscale eddies and a bottom-intensified buoyancy-driven slope water intrusion. The moored current records captured a warm-core anticyclonic eddy, which originated from the southwestern coast of Taiwan and propagated southwestward along the slope consistent with a combination of β-plane and topographic Rossby waves. The eddy was surface-intensified with a swirl speed of >50 cm/s and a vertical scale of ˜400 m. In absence of eddies and onshore deep slope water intrusion, the observed southwestward flow was highly coherent with the northeasterly wind stress. Observations did not support the existence of the permanent wintertime South China Sea Warm Current (SCSWC). The definition of SCSWC, which was based mainly on thermal wind calculations with assumed level of no motion at the bottom, needs to be interpreted with caution since the observed circulation over the NSCS shelf in winter included both barotropic and baroclinic components.

  10. Neotectonic regime on the passive continental margin of the northern South China Sea

    Science.gov (United States)

    Lüdmann, Thomas; Wong, How Kin

    1999-09-01

    Between 1989 and 1994, more than 6600 km of reflection seismic profiles were obtained in the South China Sea off Hong Kong with the German research vessel Sonne during cruises SO-50B, SO-72A and SO-95. A seismo-stratigraphic interpretation of this data set leads to a new age assignment of the unconformity T 0 which we place within the Pleistocene. Both Neogene unconformities T 1 and T 0 are generated by uplift of the Dongsha Rise and truncation of their overlying strata. This uplift is caused by intrusion of magma into the upper crust. Our seismic profiles show plutons which have penetrated the sedimentary cover, whereby their original stratification in the contact zone is eliminated. These magmato-tectonic events may be correlated to the two main collision phases between Taiwan and the continental margin of East China 5-3 and 3-0 ma ago. The collisional events subsequent to the NNW to WNW drift of Taiwan transformed the compression into strike-slip movements along the continental margin of Southeastern China. The accompanying stress regime is transtensional, with subsidence of the cooling oceanic crust since the cessation of rifting and its consumption beneath the Manila Trench providing the extensional stress. The strike-slip movements remobilized many of the rift and drift faults providing pathways for magma ascent. The tectonic framework of the northern South China Sea is characterized by Miocene faults trending NE-SW. These faults are scarce but are distributed throughout the study area. Pliocene faults striking ENE-WSW to NE-SW are concentrated west of the Dongsha Islands and are mostly strike-slip in character. Recent faults are generally oriented NE-SW subparallel to the synrift faults. They result in part from local uplifts where they are normal in character, but strike-slip motion also occurs. Most of the faults involve the basement and represent reactivated zones of weakness of the rift and drift phases.

  11. Trends of anchovy (Engraulis encrasilocus, L. biomass in the northern and central Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Alberto Santojanni

    2003-09-01

    Full Text Available Anchovy (Engraulis encrasicolus, L. is one of the most important commercial species of the northern and central Adriatic Sea. The mean annual catch of anchovy estimated by IRPEM for these areas, in the time interval 1975-1996, is equal to 25,000 tonnes. Estimates of anchovy stock biomass at sea in the time interval 1975-1996 were obtained using two population dynamics methods based on different data inputs: Virtual Population Analysis (VPA and the DeLury model with recruitment index. VPA was carried out tuning the estimated fishing mortality rate at age by fitting on corresponding Catch Per Unit of fishing Effort (CPUE. Both VPA and the DeLury model yielded sensible results. The effect on the assessments due to the use of a different birth date and thus of split-year data was investigated. Biomass values as well as patterns over time so estimated were similar on the basis of both assessment methods and calendar year versus split-year data. In particular, the biomass in more recent years (around 100,000 tonnes was lower than in the second half of the 1970s and first half of the 1980s (over 200,000 tonnes. The minimum value (lower than 50,000 tonnes was always estimated in 1987, when a strong drop in the catch and crisis of the anchovy fishery took place. Though high values of both fishing effort and fishing mortality/exploitation rate were obtained for some years before 1987, very low levels of recruitment in 1986 and 1987 seem to be mainly responsible for the collapse of the stock.

  12. Biogeochemical processes and microbial diversity of the Gullfaks and Tommeliten methane seeps (Northern North Sea)

    Science.gov (United States)

    Wegener, G.; Shovitri, M.; Knittel, K.; Niemann, H.; Hovland, M.; Boetius, A.

    2008-08-01

    Fluid flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and the underlying, deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail. At both sites, gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer. At Gullfaks a gas emitting, flat area of 0.1 km2 of sandy seabed covered by filamentous sulfur-oxidizing bacteria was detected. At Tommeliten, we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Below the patches the seafloor consisted of sand from which gas emissions were observed. At both sites, the anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16S rRNA gene sequences identified an active microbial community dominated by sulfur-oxidizing and sulfate-reducing bacteria (SRB) as well as methanotrophic bacteria and archaea. Stable carbon isotope values of specific, microbial fatty acids and alcohols from both sites were highly depleted in the heavy isotope 13C, indicating that the microbial community incorporates methane or its metabolites. The microbial community composition of both shallow seeps shows high similarities to the deep water seeps associated with gas hydrates such as Hydrate Ridge or the Eel River basin.

  13. Tectonics in the Northwestern West Philippine Basin

    Institute of Scientific and Technical Information of China (English)

    Ni Xianglong; Wu Shiguo; Shinjo Ryuichi

    2008-01-01

    The West Philippine basin (WPB) is a currently inactive marginal basin belonging to Philippine Sea plate, which has a complex formation history and various crust structures. Based on gravity, magnetic and seismic data, the tectonics in West Philippine basin is characterized by amagnma spreading stage and strike slip fractures. NNE trending Okinawa-Luzon fracture zone is a large fracture zone with apparent geomorphology and shows a right-handed movement. The results of joint gravity-magnetic-seismic inversion suggest that the Okinawa-Luzon fracture zone has intensive deformation and is a transform fault. Western existence of the NW trending fractures under Ryukyu Islands Arc is the main cause of the differences between south and north Okinawa Trough. The Urdaneta plateau is not a remained arc, but remnant of mantle plume although its lava chemistry is similar to oceanic island basalt (OIB).

  14. Does population genetic structure support present management regulations of the northern shrimp (Pandalus borealis) in Skagerrak and the North Sea?

    DEFF Research Database (Denmark)

    Knutsen, Halvor; Jorde, Per Erik; Gonzalez, Enrique Blanco;

    2015-01-01

    Population structuring in the northern shrimp (Pandalus borealis) in the North Sea area (including Fladen and Skagerrak) was studied by microsatellite DNA analyses. Screening 20 sample locations in the open ocean and Skagerrak fjords for nine loci revealed low but significant genetic heterogeneity....... The spatial genetic structure among oceanic samples of Skagerrak and the eastern North Sea was weak and non-significant, consistent with the current management regime of one single stock. However, Skagerrak fjord samples generally displayed elevated levels of genetic differentiation, and significantly so...

  15. 西菲律宾海末次冰期以来的浊流沉积及其古环境意义%TURIDITE DEPOSITION OF THE LAST GLACIAL STAGE IN THE WESTERN PHILIPPINE SEA AND ITS PALEOENVIRONMENTAL IMPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    党皓文; 翦知湣; Franck Bassinot

    2009-01-01

    Several sets of turbidite deposit were recognized from a Late Quaternary core MD 98-2188 (14.82°N, 123.49°E, water depth 730m) in the Western Philippine Sea off the Luzon Island. The turbidite layers with higher wet bulk density and lighter color contain a large amount of coarser sandy sediment and pteropod fragments, indicating that their source is shallower-water sediment. On the basis of a well-constrained age model derived from AMS ~(14)C dating and planktonic foraminiferal δ~(18)O ,it has been found that the time spans of the turbidite layers are 12.9 ~ 29.2kaB. P., 38.6 ~ 41.2kaB. P.,54. 8 ~ 55.5kaB. P.,60.1 ~ 61.1 kaB. P. And 65.1 ~ 69.7kaB. P., respectively. Accordingly, the occurrence times of the turbidite events could be inferred by the upper limit of the time spans: 12.9kaB. P., 38. 6kaB. P.,54. 8kaB. P.,60. lkaB. P. And 65. lkaB. P.,respeetively. They should correspond to the rapid sea-level rise associated with the Melt Water Pulse 1A, and the Heinrich cooling events 4,5 and 6 in Marine Isotope Stage (MIS)3,and MIS 4. Although active tectonic movement in the vicinity of the Philippine Islands could provide a possible dynamic mechanism for the destabilization of shallower-water sediments, few reliable evidences have been found to show coincidence among these turbidite events,the tephra units uncovered in core MD 98-2188 and those reported in the South China Sea and the Sulu Sea. Therefore,we suggest that the rapid sea-level rise in the last glacial and the last deglaciation might be the trigger of the turbidite deposition in core MD98-2188. This study provides new evidence to correlate the Late Quaternary sediments in the Western Philippine Sea, and to understand the environmental consequence of rapid climate change.%菲律宾海西部吕宋岛岸外MD 98-2188钻孔揭示末次冰期以来发生过数次浊流沉积事件.研究发现浊流沉积层具有密度高、颜色亮度大等物理特征,含有较多粗沉积组分和翼足类化

  16. Detection of domoic acid in northern anchovies and California sea lions associated with an unusual mortality event.

    Science.gov (United States)

    Lefebvre, K A; Powell, C L; Busman, M; Doucette, G J; Moeller, P D; Silver, J B; Miller, P E; Hughes, M P; Singaram, S; Silver, M W; Tjeerdema, R S

    1999-01-01

    The occurrence of an unusual mortality event involving California sea lions (Zalophus californianus) along the central California coast in May 1998 was recently reported. The potent neurotoxin domoic acid (DA), produced naturally by the diatom Pseudo-nitzschia australis and transmitted to the sea lions via planktivorous northern anchovies (Engraulis mordax), was identified as the probable causative agent. Details of DA analyses for anchovy tissues and sea lion feces are described. Domoic acid levels were estimated in anchovy samples by HPLC-UV, and in sea lion feces using the same method as well as a microplate receptor binding assay, with absolute confirmation by tandem mass spectrometry. The highest DA concentrations in anchovies occurred in the viscera (223 +/- 5 microg DA g(-1)), exceeding values in the body tissues by seven-fold and suggesting minimal bioaccumulation of DA in anchovy tissue. HPLC values for DA in sea lion fecal material (ranging from 152 to 136.5 microg DA g(-1)) required correction for interference from an unidentified compound. Inter-laboratory comparisons of HPLC data showed close quantitative agreement. Fecal DA activity determined using the receptor binding assay corresponded with HPLC values to within a factor of two. Finally, our detection of P. australis frustules, via scanning electron microscopy, in both anchovy viscera and fecal material from sea lions exhibiting seizures provides corroborating evidence that this toxic algal species was involved in this unusual sea lion mortality event.

  17. Contraceptive practice in the Philippines.

    Science.gov (United States)

    1989-01-01

    Contraceptive use increased substantially in the Philippines from 1983 to 1986. Prevalence increased 32.1% in 1983, 45.7% in 1986. Increase in use was among married women in Northern Mindanao, Central Visayas, Southern Tagalog, Bicol, and Western Mindanao. Prevalence remained unchanged in Southern Mindanao. During this period, modern contraceptive methods also increased with more women opting to use the pill, IUD, injectables, and sterilization. In most areas in the Philippines, contraceptive use escalated with the more traditional methods like rhythm and withdrawal. Modern family planning increased most in urban areas such as Northern and Western Mindanao. Age also played a significant part in the study. Women aged 20-24 increased usage between 1983 and 1986. A more substantial increase was noticed in the 25-49 year old group, and the highest increase came from married women aged 30-34, with at least 3-4 children, during 1983. This figure shifted in 1986 with contraceptive use becoming more pronounced among 35-39 year olds. Modern methods declined at the 40-44 age bracket due to low fecundity. Throughout the country, modern contraceptive methods were more widely practiced by working women and was defined occupationally. Women in production, labor, and service occupations displayed a low level of modern usage, while those women in professional, administrative, and technical positions were more likely to use modern methods.

  18. Phytoplankton size class derived from phytoplankton absorption and chlorophyll-a concentrations in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Guoqing; CAO Wenxi; WANG Guifen; ZHOU Wen

    2013-01-01

    A previously developed model was modified to derive three phytoplankton size classes (micro-,nano-,and pico-phytoplankton) from the overall chlorophyll-a concentration,assuming that each class has a specific absorption coefficient.The modified model performed well using in-situ data from the northern South China Sea,and the results were reliable and accurate.The relative errors of the size-fractioned chlorophyll-a concentration for each size class were:micro-:21%,nano-:41%,pico-:26%,and nano+pico:23%.The model was then applied on ocean color remote sensing data to examine the distribution and variation of phytoplankton size classes in northern South China Sea on a large scale.

  19. Variability of currents in front of the Venice Lagoon, Northern Adriatic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Cosoli, S.; Gacic, M. [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Sgonico (Trieste) (Italy); Mazzoldi, A. [Consiglio Nazionale delle Ricerche - ISMAR-CNR, Venice (Italy). Ist. di Scienze Marine

    2008-07-01

    Time scales and modes of variability of the flow in the water column in the Northern Adriatic Sea for late summer 2002 are described based on current record from a single bottom-mounted ADCP in the shallow-water area in front of the Venice Lagoon. The time averaged flow was directed 277 E (CCW), roughly aligned with the coastline, with typical magnitudes in the range 4-6 cm/s and a limited, not significant clockwise veering with depth. Tidal forcing was weak and mainly concentrated in the semidiurnal frequency band, with a barotropic (depth-independent) structure. On a diurnal time scale, tidal signal was biased by the sea-breeze regime and was characterized by a clockwise veering with depth according to the Ekman spiral. A complex EOF analysis on the velocity profile time series extracted two dominant spatial modes of variability, which explained more than 90% of the total variance in the current field. More than 78% of the total variance was accounted for by the first EOF mode, with a barotropic structure that contained the low-frequency components and the barotropic tidal signal at semidiurnal and diurnal frequencies. The second mode had a baroclinic structure with a zero-crossing at mid-depth, which was related with the response of the water column to the high-frequency wind-driven diurnal sea breeze variability. The response of low-passed non-tidal currents to local wind stress was fast and immediate, with negligible temporal lag up to mid-depth. Currents vectors were pointing to the right of wind stress, as expected from the surface Ekman veering, but with angles smaller than the expected ones. A time lag in the range 10 to 11 h was found below 8 m depth, with current vectors pointing to the left of wind stress and a counterclockwise veering towards the bottom. The delay was consistent with the frictional adjustment time scale describing the dynamics of a frictionally dominated flow in shallow water, thus suggesting the importance of bottom friction on the

  20. Coastal ocean forecasting with an unstructured grid model in the southern Adriatic and northern Ionian seas

    Science.gov (United States)

    Federico, Ivan; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo; Lecci, Rita; Mossa, Michele

    2017-01-01

    SANIFS (Southern Adriatic Northern Ionian coastal Forecasting System) is a coastal-ocean operational system based on the unstructured grid finite-element three-dimensional hydrodynamic SHYFEM model, providing short-term forecasts. The operational chain is based on a downscaling approach starting from the large-scale system for the entire Mediterranean Basin (MFS, Mediterranean Forecasting System), which provides initial and boundary condition fields to the nested system. The model is configured to provide hydrodynamics and active tracer forecasts both in open ocean and coastal waters of southeastern Italy using a variable horizontal resolution from the open sea (3-4 km) to coastal areas (50-500 m). Given that the coastal fields are driven by a combination of both local (also known as coastal) and deep-ocean forcings propagating along the shelf, the performance of SANIFS was verified both in forecast and simulation mode, first (i) on the large and shelf-coastal scales by comparing with a large-scale survey CTD (conductivity-temperature-depth) in the Gulf of Taranto and then (ii) on the coastal-harbour scale (Mar Grande of Taranto) by comparison with CTD, ADCP (acoustic doppler current profiler) and tide gauge data. Sensitivity tests were performed on initialization conditions (mainly focused on spin-up procedures) and on surface boundary conditions by assessing the reliability of two alternative datasets at different horizontal resolution (12.5 and 6.5 km). The SANIFS forecasts at a lead time of 1 day were compared with the MFS forecasts, highlighting that SANIFS is able to retain the large-scale dynamics of MFS. The large-scale dynamics of MFS are correctly propagated to the shelf-coastal scale, improving the forecast accuracy (+17 % for temperature and +6 % for salinity compared to MFS). Moreover, the added value of SANIFS was assessed on the coastal-harbour scale, which is not covered by the coarse resolution of MFS, where the fields forecasted by SANIFS

  1. Variability of currents in front of the Venice Lagoon, Northern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    S. Cosoli

    2008-05-01

    Full Text Available Time scales and modes of variability of the flow in the water column in the Northern Adriatic Sea for late summer 2002 are described based on current record from a single bottom-mounted ADCP in the shallow-water area in front of the Venice Lagoon.

    The time averaged flow was directed 277° E (CCW, roughly aligned with the coastline, with typical magnitudes in the range 4–6 cm/s and a limited, not significant clockwise veering with depth. Tidal forcing was weak and mainly concentrated in the semidiurnal frequency band, with a barotropic (depth-independent structure. On a diurnal time scale, tidal signal was biased by the sea-breeze regime and was characterized by a clockwise veering with depth according to the Ekman spiral.

    A complex EOF analysis on the velocity profile time series extracted two dominant spatial modes of variability, which explained more than 90% of the total variance in the current field. More than 78% of the total variance was accounted for by the first EOF mode, with a barotropic structure that contained the low-frequency components and the barotropic tidal signal at semidiurnal and diurnal frequencies. The second mode had a baroclinic structure with a zero-crossing at mid-depth, which was related with the response of the water column to the high-frequency wind-driven diurnal sea breeze variability.

    The response of low-passed non-tidal currents to local wind stress was fast and immediate, with negligible temporal lag up to mid-depth. Currents vectors were pointing to the right of wind stress, as expected from the surface Ekman veering, but with angles smaller than the expected ones. A time lag in the range 10 to 11 h was found below 8 m depth, with current vectors pointing to the left of wind stress and a counterclockwise veering towards the bottom. The delay was consistent with the frictional adjustment time scale describing the dynamics of a frictionally dominated flow in shallow water, thus

  2. The impact of the Arctic Sea Ice retreat on extratropical cyclones and anticyclones over Northern Eurasia: atmospheric model simulations

    Science.gov (United States)

    Akperov, Mirseid; Semenov, Vladimir; Mokhov, Igor; Lupo, Antony

    2015-04-01

    The Arctic region has been warming more than twice as fast as the other parts of the world during the last few decades. The rapid Arctic warming is accompanied with the dramatic change of Arctic sea ice cover. Recently, it has been suggested that such climatic changes might have led to the increase of anomalous weather events in winter over Northern Eurasia. One example is anomalous cold winters over Northern Eurasia associated with atmospheric blocking events. However, a large uncertainty remains concerning robustness of the observed relationship and associated mechanisms of impact. The main goal of this research is to explore the connection between the declining Arctic sea ice (most strongly expressed in the Barents-Kara Seas region) in the cold season and the change of cyclonic and anti-cyclonic activity over Northern Eurasia using simulations with atmospheric general circulation model (AGCM). The simulations were performed with the ECHAM5 AGCM using identical sea surface temperature climatology but different sea ice concentrations (SIC) for the periods corresponding to the high (1966-1969), low (1990-1995) and very low (2005-2012) SIC regimes in the Arctic as well as for the mean climatological SIC for 1971-2000. The duration of each simulation was 50 years. For the regimes with high and very low SIC, a statistically significant increase in the number of long-living anticyclones (with lifetime of more than 5 days) over Northern Eurasia was found. Long-living cyclones exhibited different changes in their number depending on their intensity. The analysis of the spatial patterns of cyclonic and anti-cyclonic activity over Eurasia was performed. We found an increase of the frequency of cyclones over the central region of the European part of Russia (EPR) and anticyclones over the northern region of the EPR for the regimes with a high sea ice concentration in the Arctic. For the regime with very low SIC the shift of the frequency of cyclones and anticyclones towards

  3. Methane seepage in the Shenhu area of the northern South China Sea: constraints from carbonate chimneys

    Science.gov (United States)

    Guan, Hongxiang; Zhang, Mei; Mao, Shengyi; Wu, Nengyou; Lu, Hongfeng; Chen, Duofu

    2016-06-01

    Two authigenic carbonate chimneys were recovered from the Shenhu area in the northern South China Sea at approximately 400 m water depth. The chimneys' mineralogy, isotopic composition, and lipid biomarkers were studied to examine the biogeochemical process that induced the formation of the chimneys. The two chimneys are composed mostly of dolomite, whereas the internal conduits and semi-consolidated surrounding sediments are dominated by aragonite and calcite. The specific biomarker patterns (distribution of lipids and their depleted δ13C values) indicate the low occurrence of methanotrophic archaea ANME-1 responsible for the chimneys' formation via anaerobic oxidation of methane. A significant input of bacteria/planktonic algae and cyanobacteria to the carbon pool during the precipitation of the carbonate chimneys is suggested by the high contributions of short-chain n-alkanes (69% of total hydrocarbons) and long-chain n-alcohols (on average 56% of total alcohols). The oxygen isotopic compositions of the carbonate mixtures vary from 3.1‰ to 4.4‰ in the dolomite-rich chimneys, and from 2.1‰ to 2.5‰ in the internal conduits, which indicates that they were precipitated from seawater-derived pore waters during a long period covering the last glacial and interglacial cycles. In addition, the mixture of methane and bottom seawater dissolved inorganic carbon could be the carbon sources of the carbonate chimneys.

  4. Turbidity characterizes the reproduction areas of pikeperch ( Sander lucioperca (L.)) in the northern Baltic Sea

    Science.gov (United States)

    Veneranta, L.; Urho, L.; Lappalainen, A.; Kallasvuo, M.

    2011-11-01

    The pikeperch ( Sander lucioperca (L.)) is an economically important fish species occurring in the fresh and brackish waters of Europe. To evaluate the distribution and extent of the reproduction areas in the northern Baltic Sea, a field survey was carried out in two separate coastal areas. Presence/absence data were used to develop a geographic information system (GIS)-based predictive spatial distribution model, where high resolution raster maps of the focal environmental variables and a logistic regression equation were used to predict the probability of larval occurrence. The results indicated that the pikeperch reproduction areas are located in the innermost archipelago zone where high water turbidity best explained their presence. Turbidity was related to several other variables such as fetch and depth. Contrary to our preliminary hypothesis, surface water temperatures measured during the survey had no significant effect in the model due to the low spatial variation in the measured values. Since turbidity is possible to determine by remote sensing methods, the probability maps can be cost-effectively extended to more extensive coastal areas with proper validation.

  5. Quantitative model of trophic interactions in Beibu Gulf ecosystem in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    CHEN Zuozhi; QIU Yongsong; JIA Xiaoping

    2006-01-01

    A mass-balanced model was constructed to determine the flow-energy in a community of fishes and invertebrates in the Beibu Gulf,northern South China Sea using Ecopath and Ecosim software. Input parameters were taken from the literature, except for the biomass of fish groups which was obtained from trawl surveys during October 1997 to May 1999 in the study area. The model consisted of 16 functional groups (boxes), including one marine mammal and seabirds, each representing organisms with a similar role in the food web, and only covered the main trophic flow in the Beibu Gulf ecosystem. The results showed that the food web of Beibu Gulf was dominated by the detrital path and benthic invertebrates played a significant role in transferring energy from the detritus to higher trophic levels; phytoplankton was a primary producer and most utilized as a food source. Fractional trophic levels ranged from 1.0 to 4.08 with marine mammals occupying the highest trophic level. Using network analysis, the system network was mapped into a linear food chain and six discrete trophic levels were found with a mean transfer efficiency of 16.7% from the detritus, 16.2% from the primary producer within the ecosystem. The biomass density of the commercially utilized species estimated by the model is 8.46 t/km2, only 0.48% of the net primary production.

  6. Measurements and modeling of the volume scattering function in the coastal northern Adriatic Sea

    Science.gov (United States)

    Berthon, Jean-François; Shybanov, Eugeny; Lee, Michael E.-G.; Zibordi, Giuseppe

    2007-08-01

    We performed measurements of the volume scattering function (VSF) between 0.5° and 179° with an angular resolution of 0.3° in the northern Adriatic Sea onboard an oceanographic platform during three different seasons, using the multispectral volume scattering meter (MVSM) instrument. We observed important differences with respect to Petzold's commonly used functions, whereas the Fournier-Forand's analytical formulation provided a rather good description of the measured VSF. The comparison of the derived scattering, bp(λ) and backscattering, bbp(λ) coefficients for particles with the measurements performed with the classical AC-9 and Hydroscat-6 showed agreement to within 20%. The use of an empirical relationship for the derivation of bb(λ) from β(ψ,λ) at ψ=140° was validated for this coastal site although ψ=118° was confirmed to be the most appropriate angle. The low value of the factor used to convert β(ψ,λ) into bb(λ) within the Hydroscat-6 processing partially contributed to the underestimation of bb(λ) with respect to the MVSM. Finally, use of the Kopelevich model together with a measurement of bp(λ) at λ=555 nm allowed us to reconstruct the VSF with average rms percent differences between 8 and 15%.

  7. An extreme internal solitary wave event observed in the northern South China Sea

    Science.gov (United States)

    Huang, Xiaodong; Chen, Zhaohui; Zhao, Wei; Zhang, Zhiwei; Zhou, Chun; Yang, Qingxuan; Tian, Jiwei

    2016-07-01

    With characteristics of large amplitude and strong current, internal solitary wave (ISW) is a major hazard to marine engineering and submarine navigation; it also has significant impacts on marine ecosystems and fishery activity. Among the world oceans, ISWs are particular active in the northern South China Sea (SCS). In this spirit, the SCS Internal Wave Experiment has been conducted since March 2010 using subsurface mooring array. Here, we report an extreme ISW captured on 4 December 2013 with a maximum amplitude of 240 m and a peak westward current velocity of 2.55 m/s. To the authors’ best knowledge, this is the strongest ISW of the world oceans on record. Full-depth measurements also revealed notable impacts of the extreme ISW on deep-ocean currents and thermal structures. Concurrent mooring measurements near Batan Island showed that the powerful semidiurnal internal tide generation in the Luzon Strait was likely responsible for the occurrence of the extreme ISW event. Based on the HYCOM data-assimilation product, we speculate that the strong stratification around Batan Island related to the strengthening Kuroshio may have contributed to the formation of the extreme ISW.

  8. mdRNA-Seq analysis of marine microbial communities from the northern Red Sea

    Science.gov (United States)

    Hou, Shengwei; Pfreundt, Ulrike; Miller, Dan; Berman-Frank, Ilana; Hess, Wolfgang R.

    2016-01-01

    Metatranscriptomic differential RNA-Seq (mdRNA-Seq) identifies the suite of active transcriptional start sites at single-nucleotide resolution through enrichment of primary transcript 5′ ends. Here we analyzed the microbial community at 45 m depth at Station A in the northern Gulf of Aqaba, Red Sea, during 500 m deep mixing in February 2012 using mdRNA-Seq and a parallel classical RNA-Seq approach. We identified promoters active in situ for five different pico-planktonic genera (the SAR11 clade of Alphaproteobacteria, Synechococcus of Cyanobacteria, Euryarchaeota, Thaumarchaeota, and Micromonas as an example for picoeukaryotic algae), showing the applicability of this approach to highly diverse microbial communities. 16S rDNA quantification revealed that 24% of the analyzed community were group II marine Euryarchaeota in which we identified a highly abundant non-coding RNA, Tan1, and detected very high expression of genes encoding intrinsically disordered proteins, as well as enzymes for the synthesis of specific B vitamins, extracellular peptidases, carbohydrate-active enzymes, and transport systems. These results highlight previously unknown functions of Euryarchaeota with community-wide relevance. The complementation of metatranscriptomic studies with mdRNA-Seq provides substantial additional information regarding transcriptional start sites, promoter activities, and the identification of non-coding RNAs. PMID:27759035

  9. Polycyclic aromatic hydrocarbons (PAHs) in the mariculture zones of China's northern Yellow Sea.

    Science.gov (United States)

    Zong, Humin; Ma, Xindong; Na, Guangshui; Huo, Chuanlin; Yuan, Xiutang; Zhang, Zhifeng

    2014-08-15

    Polycyclic aromatic hydrocarbons (PAHs) were detected in water and sediment samples collected from three mariculture zones in China's northern Yellow Sea. In these samples, total PAH concentrations ranged from 110.8 ng/L to 997.2 ng/L and 142.2 ng/gdry weight (dw) to 750.2 ng/gdw, respectively. The log KOC values of the various PAH compounds examined in this study increased with the log KOW values, which is consistent with the prediction regarding PAH behavior in the environment. However, these KOC values were lower than the predicted values as a result of the effects of organic matters, which were abundant in the mariculture water. The isomeric ratios of the PAHs in sediment indicated that the source of the PAHs in the mariculture zones were mainly pyrolytic. The TEQ(carc) values of PAHs ranged from 7 ng TEQ/gdw to 92 ng TEQ/gdw, and only a few samples met the safe criterion with respect to individual PAH concentrations.

  10. Phylogeny of culturable estuarine bacteria catabolizing riverine organic matter in the northern Baltic Sea.

    Science.gov (United States)

    Kisand, Veljo; Cuadros, Rocio; Wikner, Johan

    2002-01-01

    The objective of our study was to isolate and determine the phylogenetic affiliation of culturable estuarine bacteria capable of catabolizing riverine dissolved organic matter (RDOM) under laboratory conditions. Additions of RDOM consistently promoted the growth of estuarine bacteria in carbon-limited dilution cultures, with seasonal variation in growth rates and yields. At least 42 different taxa were culturable on solid agar media and, according to quantitative DNA-DNA hybridizations, constituted 32 to 89% of the total bacterial number in the enriched treatments. Five species in the Cytophaga-Flexibacter-Bacteroides group and one in the gamma-proteobacteria phylogenetic group (Marinomonas sp.) were numerically dominant during the stationary phase of the RDOM-enriched dilution cultures but not in the control cultures. Four of the isolates in Cytophaga-Flexibacter-Bacteroides group were putatively affiliated with the genus FLAVOBACTERIUM: All dominating isolates were determined to be new species based on comparison to the current databases. The same group of species dominated independently of the season investigated, suggesting a low diversity of bacteria catabolizing RDOM in the estuary. It also suggested a broad tolerance of the dominating species to seasonal variation in hydrography, chemistry, and competition with other species. Taken together, our results suggest that a limited group of bacteria, mainly in the Flavobacterium genus, played an important role in introducing new energy and carbon to the marine system in the northern Baltic Sea.

  11. The water clock of the Bronze Age (Northern Black Sea Coast)

    CERN Document Server

    Vodolazhskaya, Larisa N; Nevsky, Mikhail Yu

    2015-01-01

    In the article presents the results of the multidisciplinary study conducted with the help of archaeological, physical and astronomical methods. The aim of the study was to analyze and interpret marks and drawings applied to the surface of the vessel of the Bronze Age (Srubna culture) found near the Staropetrovsky village (Donetsk region, Ukraine) near the border between the Donetsk and Lugansk regions. The carried out calculations and measurements possible to prove that staropetrovsky vessel is the most ancient water clock, discovered on the territory of Europe, and have approximately the same age as the oldest known ancient Egyptian water clock. Such vessels - water clocks were needed for Srubna population to mark sundial, which had recently been discovered in the Northern Black Sea Coast. Based on the analysis of marks on the outside of the vessel, it was revealed that Staropetrovsky vessel is unique ancient complex device for measuring time and at the same time using a water clock, and with the help of a ...

  12. Immunological responses in the mussel Mytilus trossulus transplanted at the coastline of the northern Baltic Sea.

    Science.gov (United States)

    Höher, N; Turja, R; Köhler, A; Lehtonen, K K; Broeg, K

    2015-12-01

    The applicability of immune responses in transplanted Baltic blue mussels (Mytilus trossulus) as biomarkers of immunotoxic effects was studied at differently contaminated locations in the Gulf of Bothnia (northern Baltic Sea). Here, we present a detailed report on the immune responses measured as complementary part of transplantation study by Turja et al. (2014).Various immunological endpoints such as total and differential cell count, morphological alterations,phagocytic activity, and caspase 3/7 activity of mussel haemocytes as well as haemolytic activity of the haemolymph were used. Mussels collected at a reference site at a Finnish coastal site (Hanko, H) were transplanted at the Swedish coast near industrial and urban regions of the cities Sundsvall (S1, S2) and Gävle (G1, G2), respectively. Based on the measured immunological responses, multivariate statistical analysis (PCA biplot) showed a clear separation of the most polluted site S1, indicating immunotoxic impacts of the mixture of contaminants present at this location. Based on these observations and results from Turja et al. (2014), we suggest the implementation of immunotoxic biomarkers for the evaluation of ecosystem health. However, these should be accompanied by complementary endpoints of biological effects encompassing i.e., physiological, antioxidant and bioenergetic markers.

  13. High-resolution seismic-reflection data from offshore northern California — Bolinas to Sea Ranch

    Science.gov (United States)

    Sliter, Ray W.; Johnson, Samuel Y.; Chin, John L.; Allwardt, Parker; Beeson, Jeffrey; Triezenberg, Peter J.

    2016-12-05

    The U.S. Geological Survey collected high-resolution seismic-reflection data in September 2009, on survey S-8-09-NC, offshore of northern California between Bolinas and Sea Ranch.The survey area spans about 125 km of California’s coast and extends around Point Reyes. Data were collected aboard the U.S. Geological Survey R/V Parke Snavely. Cumulatively, ~1,150 km of seismic-reflection data were acquired using a SIG 2mille minisparker. Subbottom acoustic depth of penetration spanned tens to several hundred meters and varied by location and underlying sediments and rock types.This report includes maps and a navigation file of the surveyed transects, utilizing Google Earth™ software, as well as digital data files showing images of each transect in SEG-Y and JPEG formats. The images of bedrock, sediment deposits, and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management, and coastal and marine spatial planning at Federal, State and local levels. This information is also valuable for future research on the geomorphic, sedimentary, tectonic, and climatic record of central California.

  14. Spatial pattern of spring phytoplankton community in the coastal waters of northern Zhejiang, East China Sea

    Science.gov (United States)

    Ye, Ran; Cai, Yanhong; Wei, Yongjie; Li, Xiaoming

    2017-04-01

    The spatial pattern of phytoplankton community can indicate potential environmental variation in different water bodies. In this context, spatial pattern of phytoplankton community and its response to environmental and spatial factors were studied in the coastal waters of northern Zhejiang, East China Sea using multivariate statistical techniques. Results showed that 94 species belonging to 40 genera, 5 phyla were recorded (the remaining 9 were identified to genus level) with diatoms being the most dominant followed by dinoflagellates. Hierarchical clustering analysis (HCA), nonmetric multidimentional scaling (NMDS), and analysis of similarity (ANOSIM) all demomstrated that the whole study area could be divided into 3 subareas with significant differences. Indicator species analysis (ISA) further confirmed that the indicator species of each subarea correlated significantly with specific environmental factors. Distance-based linear model (Distlm) and Mantel test revealed that silicate (SiO32-), phosphate (PO43-), pH, and dissolved oxygen (DO) were the most important environmental factors influencing phytoplankton community. Variation portioning (VP) finally concluded that the shared fractions of environmental and spatial factors were higher than either the pure environmental effects or the pure spatial effects, suggesting phytoplankton biogeography were mainly affected by both the environmental variability and dispersal limitation. Additionally, other factors (eg., trace metals, biological grazing, climate change, and time-scale variation) may also be the sources of the unexplained variation which need further study.

  15. Genetic diversity of bacterial communities and gene transfer agents in northern South China Sea.

    Directory of Open Access Journals (Sweden)

    Fu-Lin Sun

    Full Text Available Pyrosequencing of the 16S ribosomal RNA gene (rDNA amplicons was performed to investigate the unique distribution of bacterial communities in northern South China Sea (nSCS and evaluate community structure and spatial differences of bacterial diversity. Cyanobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes constitute the majority of bacteria. The taxonomic description of bacterial communities revealed that more Chroococcales, SAR11 clade, Acidimicrobiales, Rhodobacterales, and Flavobacteriales are present in the nSCS waters than other bacterial groups. Rhodobacterales were less abundant in tropical water (nSCS than in temperate and cold waters. Furthermore, the diversity of Rhodobacterales based on the gene transfer agent (GTA major capsid gene (g5 was investigated. Four g5 gene clone libraries were constructed from samples representing different regions and yielded diverse sequences. Fourteen g5 clusters could be identified among 197 nSCS clones. These clusters were also related to known g5 sequences derived from genome-sequenced Rhodobacterales. The composition of g5 sequences in surface water varied with the g5 sequences in the sampling sites; this result indicated that the Rhodobacterales population could be highly diverse in nSCS. Phylogenetic tree analysis result indicated distinguishable diversity patterns among tropical (nSCS, temperate, and cold waters, thereby supporting the niche adaptation of specific Rhodobacterales members in unique environments.

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

    Science.gov (United States)

    Çiftçi Türetken, Pelin S; Altuğ, Gülşen

    2016-02-01

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

  17. Analemmatic and Horizontal Sundials of the Bronze Age (Northern Black Sea Coast)

    CERN Document Server

    Vodolazhskaya, Larisa

    2013-01-01

    The paper presents the results of a study of unique plate with images of Srubna burial of tumuli group Popov Yar-2 (Ukraine) and plate of Srubna burial of tumulus field Tavriya-1 (Russia). A distinctive feature of the images is the orderliness and symmetry of the composition, as well as the location of elliptical cupped depressions. With the help of mathematical and astronomical methods we prove in this paper that the plates with the images are the ancient sundials. At the Popov Yar-2 plate located two sundials, which worked at the same time: the analemmatic sundial and the horizontal sundial with two gnomons and the linear scale. At the Tavriya-1 plate located analemmatic sundial. On the basis of the reconstruction of the linear parameters of the gnomon of both Popov Yar-2 plate sundials and given the scale value of horizontal sundial, in the article that the potential indirect impact protoscientific knowledge of ancient Egypt to the Srubna population in the Northern Black Sea coast. Srubna burial, plate, we...

  18. Stretching characteristics and its dynamic significance of the northern continental margin of South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To investigate the thinning of the whole crust, and the contribution of the upper versus lower crust to the stretching since Cenozoic, we calculated the stretching factor of the northern margin of South China Sea with data such as whole crustal thickness, depth of Cenozoic sedimentary basement and the horizontal displacement of faults. An isometric line drawing on whole crustal stretching factor is then obtained. Along the seismic Line 1530 in Baiyun sag, we also calculated the stretching factors of the upper and lower crust. The results suggest that the whole crustal thickness decreases seaward while the whole crustal stretching factor increases from shelf to slope. The Moho upwells highest beneath where the crust is thinned most. The value of the whole crustal stretching factor ranges from 1.5 to 6. Two areas were thinned intensely: the center of Yinggehai Basin, and the Baiyun sag in the Pearl River Mouth Basin. The calculation of the upper and lower crustal stretching factors from DSP1530 in Baiyun sag shows that the original crust of Baiyun sag should be thinned before deformation. Its pre-Cenozoic evolution as well as tectonic position during Cenozoic might be responsible for that.

  19. Oligocene biogenic siliceous deposits on the slope of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The abundance of radiolarian, diatom and sponge spicule and H4SiO4 in pore-waters increase abruptly at the boundary between Early and Late Oligocene (about 30-27.5 Ma) at Site 1148 of the northern South China Sea (SCS), indicating high biogenic silica accumulation during this time. At the same time (about 30-28 Ma), high biogenic silica deposition occurred in the cen tral equatorial Pacific. Comparison of the biogenic silica accumulation at Site 1148 of the SCS with that at Site 929 of the Atlantic verifies that the biogenic silica accumulation between the low lati tude Pacific and Atlantic oceans expresses the evident relationship of compensation during theOligocene. Biogenic silica accumulation decreased in the Atlantic, whereas it increased in the Pa cific at the boundary between the Early and Late Oligocene. It resulted from the formation and presence of North Atlantic deep water (NADW) in the Atlantic basin, indicating an intensive basin-basin fractionation. XRD analysis and SEM observation of the samples from Site 1148 demon strate that most of radiolarian, diatom and sponge spicule have suffered from dissolution and reprecipitation, suggested by the opal-A→opal-CT transformation. As a result of the transformation,porosity increased, but dry and bulk densities decreased, reflecting the consequence of diagenesis on the physical property of sediment.

  20. ANALYSIS OF HUNTING STRATEGY OF UPPER PALEOLITHIC IN THE NORTHERN BLACK SEA COAST

    Directory of Open Access Journals (Sweden)

    Plohenko B. G.

    2015-02-01

    Full Text Available This article is devoted to the studying of one of the most important aspects of learning of life-support and wildlife management systems of hunting of ancient inhabitants of the Northern Black Sea Coast. Such researches are one of the main directions in sphere of studying prehistory of humankind in our country and abroad. The main aim of the research was to create the hunting pattern and to learn the chronological changes, by studying same time materials of Kamennaya Balka II, Tretij Mys, Anetolka II and Amvrosievka. During this research, the complex analysis of faunistic remainders was conducted with the help of new methods, which were developed by Russian and foreign authors. This led to a number of new high-quality results. The article shows the meaning of data which can be learnt by studying faunistic remainders and importance of such type of sources. The continuation of such research can extend our conception of life of our ancient ancestors

  1. Particulate carbohydrates and uronic acids in the northern East China Sea

    Science.gov (United States)

    Hung, Chin-Chang; Gong, Gwo-Ching; Chiang, Kuo-Ping; Chen, Hung-Yu; Yeager, Kevin M.

    2009-10-01

    Carbohydrate species, such as uronic acids, play an important role in oceanic carbon cycling, coagulation and adsorption processes. Concentrations of particulate carbohydrates (PCHO) and uronic acids (PURA) were measured in the northern East China Sea (ECS) during June and November, 2006. In June, maximum concentrations of PCHO and PURA were observed in the surface layer of coastal waters. Their concentrations rapidly decreased with depth, suggesting that they are both bio-reactive. Moreover, phytoplankton abundance and bacterial biomass seem to be associated with observed PCHO and PURA concentrations in the ECS during June, suggesting that production of carbohydrate species in the ECS is regulated by phytoplankton assemblages, bacterial assimilation or degradation. In November, however, PCHO and PURA concentrations were homogenous within the water column due to strong vertical mixing. No strong correlations were observed between carbohydrate species (PCHO and PURA) and phytoplankton or bacterial biomass, suggesting that production of these compounds in November might be caused by the physiological difference between nutrient limited and non-nutrient limited phytoplankton. Furthermore, strong negative correlations between nutrients and PCHO species suggest that nutrient levels may be one of the driving forces behind the production of these compounds in the ECS.

  2. Interannual Variability of Sea Surface Temperature in the Northern Indian Ocean Associated with ENSO and IOD

    Institute of Scientific and Technical Information of China (English)

    WU Yan-Ling; DU Yan; ZHANG Yu-Hong; ZHENG Xiao-Tong

    2012-01-01

    The Northern Indian Ocean (NIO) sea surface temperature (SST) warming, associated with the E1 Nifio/Southern Oscillations (ENSO) and the Indian Ocean Dipole (IOD) mode, is investigated using the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) monthly data for the period 1979-2010. Statistical analy- ses are used to identify respective contribution from ENSO and IOD. The results indicate that the first NIO SST warming in September-November is associated with an IOD event, while the second NIO SST warming in spring-summer following the mature phase of ENSO is associated with an ENSO event. In the year that IOD co-occurred with ENSO, NIO SST warms twice, rising in the ENSO developing year and decay year. Both short- wave radiation and latent heat flux contribute to the NIO SST variation. The change in shortwave radiation is due to the change in cloudiness. A cloud-SST feedback plays an important role in NIO SST warming. The latent heat flux is related to the change in monsoonal wind. In the first NIO warming, the SST anomaly is mainly due to the change in the latent heat flux. In the second NIO warming, both factors are important.

  3. Distribution Pattern of Photosynthetic Picoplankton and Heterotrophic Bacteria in the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yu-Ming Cai; Xiu-Ren Ning; Cheng-Gang Liu; Qiang Hao

    2007-01-01

    The environmental regulation of picoplankton distribution in the northern South China Sea was examined in winter and summer of 2004. The average abundance of Synechococcus, Prochlorococcus, and heterotrophic bacteria was lower in winter (30, 21, and 780×103 cells/cm3, respectively) than in summer (53, 85, and 1 090×103 cells/cm3,respectively), but the seasonal pattern was opposite for plcoeukaryotic phytoplankton (4 500 and 3 200 cells/cm3 in winter and summer, respectively). Synechococcus, picoeukaryotes, and bacteria were most abundant in the nutrient-rich coastal zone and continental shelf, but Prochlorococcus was most abundant in the continental slope and open ocean. The vertical distribution of each photosynthetic group and heterotrophic bacteria changed between the two seasons. Synechococcus populations with apparently different phycoerythrobilln content occurred at many stations in the summer. In addition, two different populations of Prochlorococcus were found: (i) small, weakly fluorescing cells in the surface layer; and (ii) larger, strongly fluorescent cells in the deep layer. The distribution pattern of photosynthetic picoplankton and heterotrophic bacteria depends on environmental effects and their ecophysiological differences. The distribution of Synechococcus appeared to be related to nutrient availability,whereas the distribution of Prochlorococcus appeared to be limited by temperature. Synechococcus was the only picophytoplankton with a consistent strong relationship with bacteria.

  4. Ingestion of microplastics by natural zooplankton groups in the northern South China Sea.

    Science.gov (United States)

    Sun, Xiaoxia; Li, Qingjie; Zhu, Mingliang; Liang, Junhua; Zheng, Shan; Zhao, Yongfang

    2017-02-15

    The ingestion of microplastics by five natural zooplankton groups in the northern South China Sea was studied for the first time and two types of sampling nets (505μm and 160μm in mesh size) were compared. The microplastics were detected in zooplankton sampled from 16 stations, with the fibrous microplastics accounting for the largest proportion (70%). The main component of the found microplastics was polyester. The average length of the microplastics was 125μm and 167μm for Nets I and II, respectively. The encounter rates of microplastics/zooplankton increased with trophic levels. The average encounter rate of microplastics/zooplankton was 5%, 15%, 34%, 49%, and 120% for Net I, and 8%, 21%, 47%, 60%, and 143% for Net II for copepods, chaetognaths, jellyfish, shrimp, and fish larvae, respectively. The average abundance of microplastics that were ingested by zooplankton was 4.1pieces/m(3) for Net I and 131.5pieces/m(3) for Net II.

  5. Seasonal variations in diversity and abundance of surface ichthyoplankton in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Kaizhi; YIN Jianqiang; HUANG Liangmin; LIN Zhaojin

    2014-01-01

    The objective of this study was to investigate the seasonal variations of ichthyoplankton diversity and abun-dance in the northern South China Sea based on the data collected during summer, winter and spring. In total, 95 taxa of larval fishes were identified. The greatest number of species was recorded in spring, followed by summer and winter. The number of species was distributed mainly in the coastal waters from the east of Leizhou Peninsula to the southeast of Hainan Island during the surveyed periods of summer and spring, but in the offshore waters during winter. The abundance of larval fish was lowest in winter, increased in spring, and reached the maximum in summer. High abundance of larval fish was generally restricted to coastal waters with the isobaths less than 50 m. Seasonal variations of larval fish richness, abundance and diversity index were significant (P<0.001). Carangidae was the most common and abundant taxon in summer and winter, whileSardinella sp.,Thrissa mystax andLeiognathus sp. were dominant in spring. High diversity and abundance of larval fish might be attributed to increased temperature and coastal upwelling in spring and summer.

  6. Ecological risk assessment of arsenic and metals in sediments of coastal areas of northern Bohai and Yellow Seas, China

    OpenAIRE

    Luo, Wei; Lu, Yonglong; Wang, Tieyu; Hu, Wenyou; Jiao, Wentao; Naile, Jonathan E.; Khim, Jong Seong; Giesy, John P.

    2010-01-01

    Distributions of arsenic and metals in surface sediments collected from the coastal and estuarine areas of the northern Bohai and Yellow Seas, China, were investigated. An ecological risk assessment of arsenic and metals in the sediments was evaluated by three approaches: the Sediment Quality Guidelines (SQGs) of the United States Environmental Protection Agency (USEPA), the degree of contamination, and two sets of SQGs indices. Sediments from the estuaries of the Wuli and Yalu Rivers contain...

  7. Chemical oceanography of the Arabian Sea: Part III - Studies on nutrient fraction and stoichiometric relationship in the Northern and the Eastern Basins

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Sankaranarayanan, V.N.; DeSousa, S.N.; Fondekar, S.P.

    Phosphorus and inorganic nitrogen compounds have been divided into 'reserved' andoxidative fractions based on their relationships with apparent oxygen utilization in the northern and the north-eastern basins of the Arabian Sea.Two oxygen minima...

  8. AFSC/NMML/CCEP: Hookworm Intensity of Infection in California sea lion and Northern Fur Seal Pups in California, 1996 through 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There are various causes of mortality for California sea lion (Zalophus californianus) and northern fur seal (Callorhinus ursinus) pups. This dataset contains...

  9. Modeling of Air-Sea Interaction and Ocean Processes for the Northern Arabian Sea Circulation Autonomous Research Project

    Science.gov (United States)

    2015-09-30

    understand and quantify the upper ocean physical processes that determine the air-sea interaction, mixed layer dynamics, ocean circulation dynamics...mature phases of the monsoon is a key to the circulation in the northwestern Indian Ocean and Arabian Sea NASCar will make use of autonomous... circulation of the Arabian Sea, the equatorial wave guide and the boundary currents in southern Indian Ocean . Better understanding of the short term

  10. Deep-water Fan Systems and Petroleum Resources on the Northern Slope of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    PANG Xiong; YANG Shaokun; ZHU Ming; LI Jinsong

    2004-01-01

    The shallow shelf delta/strand arenaceous-pelitic deposit region in the north of the Pearl River mouth basin,sitting on the northern continental shelf of the South China Sea, has already become an important oil production base in China. Recent researched has revealed that a great deal of deep-water fans of great petroleum potentiality exist on the Baiyun deep-water slope below the big palco Pearl River and its large delta. Based on a mass of exploration wells and 2-D seismic data of the shallow shelf region, a interpretation of sequence stratigraphy confirmed the existence of deep-water fans. The cyclic falling of sea level, abundant detrital matter from the paleo Pearl River and the persistent geothermal subsidence in the Baiyun sag are the three prerequisites for the formation and development of deep-water fans. There are many in common between the deep-water shelf depositional system of the northern South China Sea and the exploration hotspots region on the two banks of the Atlantic. For example, both are located on passive continent margins, and persistent secular thermal subsidence and large palco rivers have supplied abundant material sources and organic matter.More recently, the discovery of the big gas pool on the northern slope of the Baiyun sag confirms that the Lower Tertiary lacustrine facies in the Baiyun sag has a great potentiality of source rocks. The fans overlying the Lower Tertiary source rocks should become the main exploration areas for oil and gas resources.

  11. Fishing management scenarios to rebuild exploited resources and ecosystems of the Northern-Central Adriatic (Mediterranean Sea)

    Science.gov (United States)

    Fouzai, Nadia; Coll, Marta; Palomera, Isabel; Santojanni, Alberto; Arneri, Enrico; Christensen, Villy

    2012-10-01

    We examined various fishing management options to recover exploited marine resources and ecosystems of the Northern-Central Adriatic Sea. Dynamic simulations were based on a spatial ecological model previously calibrated with time series of data. Scenarios regarding spatial management were evaluated with the establishment of two marine protected areas, respectively, in the Pomo pit and the northern region. In addition, three temporal simulations of temporary closures and overall reduction of fishing effort of demersal and pelagic fleets (bottom, mid-water trawls and purse seines) were also considered. Simulations were run for 45 years (1975-2020), including the calibration period (1975-2002), and changes in biomass and catch of marine resources were analyzed. Our results confirm that current fishing management in the Adriatic Sea does not have clear beneficial impacts for the recovery of exploited resources, which will remain depleted in 2020 if "business as usual" continues. Simulations of alternative management suggest that both protected areas could be beneficial for fish population recovery predicting an increase in the biomass of commercial fish and predatory organisms. Simulations of temporary closures and overall reduction of fishing effort also show significant benefits for several commercial resources. We argue that both management measures may be effective tools to recover exploited ecosystems of the Northern-Central Adriatic Sea and halt the decline of marine resources.

  12. Exploration Potential of Atectonic Oil-gas Pools in the Northern Shelf Basin of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZhuWeilin; WangZhenfeng; LvMing

    2004-01-01

    Large-scale oil exploration has been done and large quantities of oil-gas fields have been found in the northern shelf basin of the South China Sea for more than 20 years. The tectonic oil-gas pools are the main type. With the exploration to be deepened, looking for atectonic oil-gas pools is listed in China's exploration strategy. There are advantages for the forming of atectonic oil-gas pools in the northern shelf basin of the South China Sea. Because the level of water has been frequently changing within all historical periods, lithozones are changed alternately in both vertical and lateral directions and formed lithologic deposition especially at low water level stages, such as the low-lying fans of basin-floor fans and slope fans. Due to frequent tectonic movement within all historical periods, many structural surfaces and structural unconformities were formed. At the same time, they also formed many kinds of structural unconformity oil-gas pools. According to our exploration and research, the promising areas of atectonic reservoirs within marine basins include: (1) the basin-floor fan of the deep water district, such as the central depression of the Southeast Qiong basin and Baiyun sag in the Zhujiangkou basin; (2) the frontal area of the large ancient delta, such as the Lingao structural belt in the Yingge Sea basin and Huizhou sag in the Zhujiangkou basin; (3) the unconformity pinchout belt or denudation belt in the slope area and the uplift area, for instance, the Yingdong slope belt in the Yingge Sea basin and Yacheng 13-1 structural belt in the southeast Qiong basin. All this proves that the prospects for atectonic oil-gas pools in the northern shelf basin of the South China Sea are very broad.

  13. Growth dynamics of saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) in the Northern Bering and Chukchi Seas

    Science.gov (United States)

    Helser, Thomas E.; Colman, Jamie R.; Anderl, Delsa M.; Kastelle, Craig R.

    2017-01-01

    Saffron cod (Eleginus gracilis) and Arctic cod (Boreogadus saida) are two circumpolar gadids that serve as critically important species responsible for energy transfer in Arctic food webs of the northern Bering and Chukchi Seas. To understand the potential effects of sea ice loss and warming temperatures on these species' basic life history, information such as growth is needed. Yet to date, limited effort has been dedicated to the study of their growth dynamics. Based on a large sample of otoliths collected in the first comprehensive ecosystem integrated survey in the northern Bering and Chukchi Seas, procedures were developed to reliably estimate age from otolith growth zones and were used to study the growth dynamics of saffron and Arctic cod. Annual growth zone assignment was validated using oxygen isotope signatures in otoliths and otolith morphology analyzed and compared between species. Saffron cod attained larger asymptotic sizes (L∞=363 mm) and achieved their maximum size at a faster rate (K=0.378) than Arctic cod (L∞=209 mm; K=0.312). For both species, regional differences in growth were found (pArctic cod grew to smaller asymptotic size but at faster rates in the more northerly central (L∞=197 mm;K=0.324) and southern Chukchi Sea (L∞=221 mm;K=0.297) when compared to the northern Bering Sea (L∞=266 mm;K=0.171), suggesting a possible cline in growth rates with more northerly latitudes. Comparison of growth to two periods separated by 30 years indicate that both species exhibited a decline in maximum size accompanied by higher instantaneous growth rates in more recent years.

  14. The Philippines: Historical Overview.

    Science.gov (United States)

    Shackford, Julie; Aquino, Belinda A., Ed.

    This book provides readings and student lessons about the Philippines. Lessons and activities follow a chronological sequence and provide a good resource for those interested in the Philippines. The materials begin with prehistoric times and continue to the presidency of Corazon Aquino. Each chapter provides background information along with a…

  15. The Philippines: Historical Overview.

    Science.gov (United States)

    Shackford, Julie; Aquino, Belinda A., Ed.

    This book provides readings and student lessons about the Philippines. Lessons and activities follow a chronological sequence and provide a good resource for those interested in the Philippines. The materials begin with prehistoric times and continue to the presidency of Corazon Aquino. Each chapter provides background information along with a…

  16. Oxygen isotope stratigraphy and events in the northern South China Sea during the last 6 million years

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the stable isotopic analysis of more than 1000 samples of planktonic and benthic foraminifers from ODP Site 1148 in the northern South China Sea (SCS), the oxygen iso tope stratigraphy has been applied to the last 3 million years for the first time in the SCS. Further more, the paleoceanographic changes in the northern SCS during the last 6 million years have been unraveled. The benthic foraminiferaδl8O record shows that before ~3.1 Ma the SCS was much more influenced by the warm intermediate water of the Pacific. The remarkable decrease in the deepwater temperature of the SCS during the period of 3.1-2.5 Ma demonstrates the forma tion of the Northern Hemisphere ice-sheet. However, the several sea surface temperature (SST)reductions during the early and middle Pliocene, reflected by the planktonic foraminiferal δ18O,might be related to the ice-sheet growth in the Antarctic region. Only those stepwise and irreversi ble SST reductions during the period of ~2.2-0.9 Ma could be related to the formation and growth of the Northern Hemisphere ice-sheet.

  17. Patch-reef morphology as a proxy for Holocene sea-level variability, Northern Florida Keys, USA

    Science.gov (United States)

    Brock, J.C.; Palaseanu-Lovejoy, M.; Wright, C.W.; Nayegandhi, A.

    2008-01-01

    A portion of the northern Florida Keys reef tract was mapped with the NASA Experimental Advanced Airborne Research Lidar (EAARL) and the morphology of patch reefs was related to variations in Holocene sea level. Following creation of a lidar digital elevation model (DEM), geospatial analyses delineated morphologic attributes of 1,034 patch reefs (reef depth, basal area, height, volume, and topographic complexity). Morphometric analysis revealed two morphologically different populations of patch reefs associated with two distinct depth intervals above and below a water depth of 7.7 m. Compared to shallow reefs, the deep reefs were smaller in area and volume and showed no trend in topographic complexity relative to water depth. Shallow reefs were more variable in area and volume and became flatter and less topographically complex with decreasing water depth. The knoll-like morphology of deep reefs was interpreted as consistent with steady and relatively rapidly rising early Holocene sea level that restricted the lateral growth of reefs. The morphology of shallow 'pancake-shaped' reefs at the highest platform elevations was interpreted as consistent with fluctuating sea level during the late Holocene. Although the ultimate cause for the morphometric depth trends remains open to interpretation, these interpretations are compatible with a recent eustatic sea-level curve that hindcasts fluctuating late Holocene sea level. Thus it is suggested that the morphologic differences represent two stages of reef accretion that occurred during different sea-level conditions. ?? 2008 Springer-Verlag.

  18. Sporopollen and algae research of core B106 in the northern South China Sea and its paleoenvironmental evolution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the high-resolution sporopollen and algae research of the sediments from core B106 in the northem South China Sea,three sporopollen assemblage zones have been distinguished in ascending order:Zone 1 (294-194 cm):pinus-Quercus (evergreen)-Gramineae-Polypodia-ceae- Pterdium-Dicranopteris.Zone 2 (194-94 cm):Pinus-Quercus (evergreen)-Polypodiaceae-Pteridium- Dicranopteris.Zone 3 (94-4 cm):Pinus-Polypodiaceae-Pteridium-Quercus(evergreen)-Dicranopteris.The three sporopollen zones correspond to three stages of vegetation,climate and paleoenvironment evolution of the northern part of the South China Sea since 11 000 years ago.Combined with AMS 14C dating,the sporopollen and algae data can be a scientific basis for stratigraphic division and reconstruction of paleoclimate and paleoenvironment in the South China Sea.

  19. Chemistry of the sea-surface microlayer. 3. Studies on the nutrient chemistry of the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Singbal, S.Y.S.; Narvekar, P.V.; Nagarajan, R.

    with Chlorophyll values at 1 m depth. Relatively high enrichment factors, sea-surface microlayer (SML), in coastal waters could be attributed to the influence of freshwater carrying considerable quantities of nutrients into the sea either from land runoff or from...

  20. Relationship between coral growth rate and sea surface temperature in the northern part of South China Sea during the past 100 a

    Institute of Scientific and Technical Information of China (English)

    聂宝符; 陈特固; 梁美桃; 王有强; 钟晋梁; 朱袁智

    1997-01-01

    To research the relationship between coral growth rate and sea surface temperature ( Tss), 5 cores of living Porites lutea were collected from the Xisha Islands and the southern Hainan Island waters and measured. The results of the study show that there is an obviously positive correlation between the coral growth rates and the Tss records from the northern part of South China Sea. The annual growth rates of the five samples of Porites lutea during the past 100 a are in the range of 7-15 mm/a, and their mean value is 11 mm/a. The correlation coefficients between the coral growth rates and the Tss records from the waters during 1961-1993 are in the range of 0. 77-0.89. As a result, a thermometer of the coral growth rate is established. A hindcasting Tss in the waters from 1993 to 1961 has been obtained with an error of about 0.12-0.17℃ . Based upon the calculated result, the rising rate of Tss in the northern part of South China Sea during the past 100 a is 0. 20℃ , which is higher than that of the air

  1. Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Hu Dengke; Zhou Di; Wu Xiangjie; He Min; Pang Xiong; Wang Yuwei

    2009-01-01

    The newly acquired long-cable multi-channel seismic (MCS) lines were used to study the crustal structure and extension in an NW-SE elongated 150 km by 260 Van strip from the slope to the deepsea basin in the northern South China Sea (SCS).These profdes are of good penetration that Moho is recognizable in ~70% length of the lines.Seismostrattgraphic interpretation and time-depth conversion were conducted.A power function D = atb+ c was used in the time-depth conversion,which avoided the under-or over-estimation of the depths of deep-seated interfaces by cubic or quadratic polynomial functions.Contour maps of basement depth,Moho depth,crustal thickness,and crustal stretching factor were obtained for the study area.In the dip direction,the Moho depth decreases stepwisely from 28 km in the outer shelf southwards to 19,15,and 12 km in the deepsea basin,with ramps at the shelf break,lower slope,and the continent ocean boundary (COB),respectively.Accordingly,the crustal thickness decreased southwards from 3,and 7 km spectively.Under the center of the Balynn (白云) sag,the crust thins significantly to < 7 kin.The crustal stretching factor βc was calculated by assuming the original crust thickness of 30 km.In the centers of the Baiyun sag,βc exceeds 5.Tertiary and Quaternary volcanic activities show a general trend of intensifying towards the COB.An important finding of this study is the along-strike variation of the crustal structure.A Moho rise extends from the COB NW-ward until the shelf break,about 170 km long and 50-100 km wide,with Moho depth < 20 kin.This is called the Balyun Moho Nose,which is bounded to the east,west,and north by belts of high Moho gradients indicative of crustal or even lithospheric faults.The doming of Moho in the nose area might he the cause of the W-E segmentation of the crustal and geological structures along the slope of the northern South China Sea,and the cause of the strong crustal

  2. Composition and genesis of ferromanganese deposits from the northern South China Sea

    Science.gov (United States)

    Zhong, Yi; Chen, Zhong; González, Francisco Javier; Hein, James R.; Zheng, Xufeng; Li, Gang; Luo, Yun; Mo, Aibin; Tian, Yuhang; Wang, Shuhong

    2017-05-01

    Marine ferromanganese (Fe-Mn) nodules and crusts are archives of past environmental conditions and potential mineral resources. Over the last 30 years, many have been discovered in the northern South China Sea (SCS). To determine the origin of the Fe-Mn deposits, a comprehensive laboratory analysis of physical properties, mineralogy and geochemistry was conducted on newly collected Fe-Mn nodule/crust samples. The results revealed that there are three types of Fe-Mn deposits: (1) Fe-rich nodules containing essentially goethite occur on the northeastern slope of the SCS, with high Fe, low Mn (Mn/Fe = 0.03) and low trace metals and rare earth elements concentrations; (2) Smooth Fe-Mn nodules and crusts composed of asbolane, todorokite and CFA occur along the northwestern marginal of the SCS that have similar Fe and Mn contents (Mn/Fe = 1.21), moderate trace metal enrichments, and a positive Ce anomaly; (3) Fe-Mn nodules and crusts composed of asbolane, todorokite and birnessite that occur in the central basin of the SCS have higher Mn and lower Fe contents (Mn/Fe = 1.45). This depositional pattern was associated with major changes in oceanographic conditions and tectonic regimes. The northeastern slope deposits occur in a contourite depositional system, are strongly enriched in Fe relative to Mn (average 38.7% and 0.96%, respectively), formed from the combination of hydrogenetic and diagenetic processes. We propose a new genetic model for Fe-Mn nodules, which formed through the oxidation of pyrite and pyrite-barite concretions that formed by rapid early diagenetic growth (average 3320 mm/Myr) on continental margins above the carbonate compensation depth, and dominated by hydrocarbon seep structures and strong erosive action of bottom currents along the northeastern slope. In contrast, the introduction of vigorous deep-water flow from the North Pacific promoted the slow growth (4-7 mm/Myr) of hydrogenetic Fe-Mn nodules and crusts along the northwestern margin. Finally

  3. Seasonal variations in carbon biomass of bacteria, thraustochytrids and microzooplankton in the Northern Arabian Sea

    Science.gov (United States)

    Ramaiah, N.; Raghukumar, S.; Mangesh, G.; Madhupratap, M.

    2005-07-01

    As a part of the JGOFS-India Programme, abundance of heterotrophic bacteria (Hbac; 0-2000 m), thraustochytrids (0-2000 m), microzooplankton (0-200 m occasionally up to 300 m) as well as bacterial growth rates (0-500 m) were studied in the Northern Arabian Sea (NAS) during Spring (SpIM) and Fall intermonsoon (FIM), Northeast Winter (Win) and Summer (SuM) monsoon seasons. Hbac abundance was mostly in the range of 10 8-10 9 cells l -1 in the surface (0-100 m) and intermediate (150-400 m) depths. Thraustochytrids (heterotrophic protists rich in polyunsaturated fatty acids) were roughly in the range of 10 3 l -1 (nil to ˜2.7×10 5). Below 200 m, they decreased drastically to values between nil and 10 l -1. Seasonal differences in carbon biomass of Hbac, thraustochytrids and microzooplankton were more pronounced than those seen in the mesozooplankton. The highest Hbac C biomass was observed during FIM. Bacterial carbon demand (BCD, mg C m -3 d -1; at an assumed 33% conversion efficiency) varied from 0.45 to 40.6 in FIM, 23.43 to 100 in SpIM, 2.31 to 17.5 in Win and from 6.6 to 25.4 in SuM in the top 100 m. In general, with increasing depth the BCD decreased quite rapidly ranging from 0.007 to 1.65 mg C m -3 d -1 below 100 m. In the NAS, heterotrophic bacteria appear to play a significant role in sustaining microzooplankton and the so-called 'Arabian Sea mesozooplankton stable-biomass paradox' through microbial loop. Sizable quantities of Hbac, thraustochytrids and microzooplankton C might be suggestive that Hbac support these microheterotrophs, in mesopelagic zone in particular. Their role in sustaining a variety of deep-water micro- and mesozooplanktonic communities as well as in some ways, the myctophids ingesting marine snow (enriched with bacteria, thraustocytrids and dead organic matter besides zooplankters) is brought to attention.

  4. Recognition of relict Mesozoic Dongsha Basin in the northern margin, South China Sea and its implication

    Science.gov (United States)

    Yan, Pin; Wang, Yanlin

    2015-04-01

    The Pearl River Mouth Basin (PRMB) is dominated by NE-trending rift architecture produced mainly during Cenozoic Era. It comprises a series of grabens built up with thick Paleogene and thick Neogene sediments, up to 12000 m, and dividing basement highs composing Yanshanian granitic rocks. Though previously considered as one constituent part of PRMB in the southeast, Dongsha Basin displays major differences in sedimentary architecture and tectonic framework. Firstly, Dongsha Basin is characterized by a prominent angular unconformity, interpreted as a spectacular planation or rough erosion surface which separates the sediment column into two distinct parts. It is interpreted with accumulating seismic and drill data that the underlying strata comprise Early Cretaceous terrestrial, Jurassic marine and possibly Triassic sedimentary rocks totaling to 4~9 km thick, whereas the overlying strata are very thin (usually 0.5~1 km in whole) composing mainly Neogene sediments. The major sedimentary hiatus between them corresponds to the Late Cretaceous to mid-Miocene Epoch, well during the rifting to spreading process when the PRMB developed. Secondly, unlike the PRMB, the Dongsha Basin has suffered considerably less extension except its boundary areas, and actually remained as a relatively stable block though Cenozoic Era. Moreover, there are a few compressive open fold structures within the buried Mesozoic strata over the central Dongsha Basin. These folds trend in NNE and are characterized mostly by few minor growing upthrust faults with offsets in the order of few tens to hundreds meter. The upthrust faults dipped mostly southeastward against the northwestward subduction of paleo-Pacific plate as postulated in other previous study. The blind folds featured more like back-thrust growth tectonics, formed a broad NNE-SSW trending belt, obviously oblique to the trend of northern margin of the South China Sea and the PRMB as well. In a few recent models, the most prominent

  5. The Calm Methane Northern Seas of Titan from Cassini Radio Science Observations

    Science.gov (United States)

    Marouf, Essam A.; French, Richard G.; Wong, Kwok; Anabtawi, Aseel; Schinder, Paul J.; Cassini Radio Science Team

    2016-10-01

    We report on results from 3 bistatic scattering observations of Titan northern seas conducted by the Cassini spacecraft in 2014 ( flybys T101, T102, and T106). The onboard Radio Science instrument transmits 3 sinusoidal signals of 0.94, 3.6, and 13 cm wavelengths. The spacecraft is continuously maneuvered to point in incidence direction so that mirror-like reflections from Titan's surface are observed at the ground stations of the NASA Deep Space Network. The corresponding ground-track in all 3 cases crossed different regions of Kraken Mare, and in the case of T101 also crossed Ligeia Mare. A nearly pure sinusoidal reflected signal was clearly detectable in the observed echoes spectra over surface regions identified in the Cassini RADAR images as potential liquid regions. Weaker quasi-specular echoes were also evident over some intermediate dry land and near sea shores. Cassini transmits right-circularly-polarized (RCP) signals and both the RCP and LCP echo components are observed. Their spectral shape, bandwidth, and total power are the observables used to infer/constrain physical surface properties. Presented results are limited to the 3.6 cm wavelength signal which has the largest SNR. The remarkably preserved sinusoidal echo spectral shape and the little detectable Doppler broadening strongly suggest surface that is smooth on scales large compared to 3.6 cm. If long wavelength gravity waves are present, they must be very subtle. The measured RCP/LCP echo power ratio provides direct measurement of the surface dielectric constant and is diagnostic of the liquid composition. The power ratio measurements eliminate possible significant ethane contribution and strongly imply predominantly liquid methane and nitrogen composition. Carefully calibrated measurements of the absolute echo power and the inferred dielectric constant constrain the presence of any capillary waves of wavelength << 3.6 cm. The latter affect wave coherence across the Fresnel region, reducing the

  6. Biogeochemical processes and microbial diversity of the Gullfaks and Tommeliten methane seeps (Northern North Sea

    Directory of Open Access Journals (Sweden)

    G. Wegener

    2008-02-01

    Full Text Available Fluid-flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and underlying deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail: at both sites gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer as indicated by acoustic images of the gas flares. At Gullfaks a 0.1 km2 large gas emission site was detected on a flat sandy seabed, covered by filamentous sulfide-oxidizing bacteria. At Tommeliten we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Here the seafloor consists of layers of sand and stiff clay, and gas emission was observed from small cracks in the seafloor. At both sites the anaerobic oxidation of methane (AOM coupled to sulfate reduction is the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16 S rRNA gene sequences identified an active microbial community dominated by sulfide-oxidizing and sulfate-reducing bacteria (SRB as well as methanotrophic bacteria and archaea. Carbon isotope values of specific microbial fatty acids and alcohols were highly depleted, indicating that the microbial community at both gas seeps incorporates methane or its metabolites. The microbial community composition of both shallow seeps show high similarities to the deep water

  7. Biogeochemical processes and microbial diversity of the Gullfaks and Tommeliten methane seeps (Northern North Sea

    Directory of Open Access Journals (Sweden)

    G. Wegener

    2008-08-01

    Full Text Available Fluid flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and the underlying, deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail. At both sites, gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer. At Gullfaks a gas emitting, flat area of 0.1 km2 of sandy seabed covered by filamentous sulfur-oxidizing bacteria was detected. At Tommeliten, we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Below the patches the seafloor consisted of sand from which gas emissions were observed. At both sites, the anaerobic oxidation of methane (AOM coupled to sulfate reduction (SR was the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16S rRNA gene sequences identified an active microbial community dominated by sulfur-oxidizing and sulfate-reducing bacteria (SRB as well as methanotrophic bacteria and archaea. Stable carbon isotope values of specific, microbial fatty acids and alcohols from both sites were highly depleted in the heavy isotope 13C, indicating that the microbial community incorporates methane or its metabolites. The microbial community composition of both shallow seeps shows high similarities to the deep water seeps associated with gas hydrates such as

  8. On measurements of aerosol-gas composition of the atmosphere during two expeditions in 2013 along the Northern Sea Route

    Science.gov (United States)

    Sakerin, S. M.; Bobrikov, A. A.; Bukin, O. A.; Golobokova, L. P.; Pol'kin, Vas. V.; Pol'kin, Vik. V.; Shmirko, K. A.; Kabanov, D. M.; Khodzher, T. V.; Onischuk, N. A.; Pavlov, A. N.; Potemkin, V. L.; Radionov, V. F.

    2015-11-01

    We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in areas of the Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August-22 September 2013) and RV Professor Khljustin (24 July-7 September 2013). The specific features of spatial distribution and time variations of aerosol optical depth (AOD) of the atmosphere in the wavelength range of 0.34-2.14 μm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov) there is a decrease in aerosol and black carbon concentrations in a northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 μm) values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m-3, respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from the Japan Sea to the Chukchi Sea, the aerosol number concentration decreased on average from 23.7 to 2.5 cm-3, the black carbon mass concentration decreased from 150 to 50 ng m-3, and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at a latitude of ~ 55° N. For water basins of eight seas, we present the chemical compositions of the water-soluble aerosol fraction (ions, elements) and small gas-phase species, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75-89 %) supplied from the atmosphere to the sea

  9. Palaeoecology and geoarchaeology of the Varna Lake, northern Bulgarian Black Sea coast

    Directory of Open Access Journals (Sweden)

    Mariana FILIPOVA-MARINOVA

    2014-11-01

    Full Text Available The coastal lakes are rich sources of biostratigraphic information that is very useful in palaeoecological reconstructions of climate changes and human impact on the natural vegetation. This information is of great importance for the archaeological descriptions of submerged praehistorical settlements found in the northern Bulgarian Black sea area. There are 4 archaeological sites in this area that have been palynologically studied for the last 30 years: the Durankulak Lake, the Shabla-Ezeretz Lake system, the Lake Bolata, as well as the Varna-Beloslav Lake system. Because of the lack of AMS radiocarbon dates for these sites, it was not possible to correlate adequately all palaeoenvironmental results with the available archaeological chronology.Aimed to receive additional information on the Holocene vegetation dynamics and lake level changes, as well as on the anthropogenic impact during the Late Eneolithic and Early Bronze Age, the high-resolution spore-pollen analysis of AMS dated laminated sediments from a new Core 3 – Varna Lake was combined with analyses of dinoflagellate cysts, acritarchs, and other non-pollen palynomorphs.The location of the core is close to several sites of submerged praehistorical settlements and the Varna Late Eneolithic (Chalcolithic Necropolis, which is famous with the oldest hand-made gold treasure in the Worlds, and permits the palaeoenvironmental correlations of obtained results with available archaeological and geochronological data. The core is 995 cm long, but its palynologically investigated length is 870 cm. It contains dark grey clay and laminated sediments (varves. Seven samples of sediments were submitted for radiocarbon dating to the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS Facility of Woods Hole Oceanographic Institution (WHOI. The dates have been calibrated using the program CALIB version 6.1.0 of using the IntCal09 curve. An Age Model for the sedimentation rate was created by the

  10. Association of Colloidal Organic Matter and Metals in Coastal Waters (Gulf of Trieste, Northern Adriatic Sea)

    Science.gov (United States)

    Faganeli, J.; Klun, K.; Falnoga, I.; Mazej, D.; Kovač, N.

    2016-12-01

    Large volumes of seawater were sampled in the Gulf of Trieste (northern Adriatic Sea) in order to study the seasonal changes of interactions between colloidal organic matter (COM) and metals/metalloids (Me) in coastal waters. Isolation of COM (>5 kDa) was performed by ultrafiltration and final desalinization by dialysis. COM was characterized using 1H NMR and FTIR spectroscopy, and C and N elemental, and 13C and 15N isotope analyses. COM represents about 1/4 of DOC and appears to be mainly of marine origin. COM is composed of polysaccharides (30-45%), lipids (30-55%), proteins (15-20%) and humics (OH (carbohydrates and lipids), COOH (proteins and lipids) and NH (proteins) functional groups. In the late spring - early summer, an accumulation of COM was observed, demostrated by HPSEC, indicating the possible path of macroaggregate formation. The polysaccharide and lipid fractions increased and the protein fraction decreased. COM isolated from phytoplankton cultures (Tetraselmis marina, Chaetoceros socialis, Prorocentrum minimum) from the gulf indicated that phytoplankton mostly contributes to the polysaccharide COM pool. Analyses of Me, performed by ICPMS and CVAFS (Hg), showed that Hg (>90%), V (35%), Cu (20%), Cr (10%) and Se (10%) have the highest Me affinity to COM. Similarly to COM, Hg and Cu rapidly decreased in summer due to their sequestration in aggregates (transfer into particulate phase) and increased microbial degradation. The observed Me/Corg. ratios (Co, Cd, Hg, < U, Cr, Ni, Mn < As, Zn, Cu, V < Fe) somewhat differ from those of Irving-Williams series and can be explained by composition of COM and variable background concentrations of studied Me. Data from the salinity gradient in the gulf showed flocculation of Al and Cu and desorption of V, Mn, As, Se, Rb, Sr, Ag, Cd, Cs, Tl, U and Hg from the riverine particles with increasing ionic strength while Fe, Cr, Ni, Zn and Pb did not correlate with salinity.

  11. Characteristics and Formation Mechanism of Polygonal Faults in Qiongdongnan Basin,Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Sun Qiliang; Wu Shiguo; Yao Genshun; LI Fuliang

    2009-01-01

    Based on high-resolution 3D seismic data,we document the polygonal faults within the Miocene Meishan (梅山) Formation and Huangliu (黄流) Formation of the Qiongdongnan (琼东南)basin,northern South China Sea.Within the seismic section and time coherent slice,densely distributed extensional faults with small throw and polygonal shape were identified in map view.The orientation of the polygonal faults is almost isotropic,indicating a non-tectonic origin.The deformation is clearly layer-bounded,with horizontal extension of 11.2% to 16%,and 13.2% on average.The distribution of polygonal faults shows a negative correlation with that of gas chimneys.The development of polygonal faults may be triggered by over-pressure pore fluid which is restricted in the fine-grained sediments of bathyal facies when the sediments is compacted by the burden above.The polygonal faults developed to balance the volumetric contraction and restricted extension.The product of hydrocarbon in the Meishan Formation may have contributed to the development of the polygonal faults.In the study area,it was thought that the petroleum system of the Neogene post-rift sequence is disadvantageous because of poor migration pathway.However,the discovery of polygonal faults In the Miocene strata,which may play an important role on the fluid migra-tion,may change this view.A new model of the petroleum system for the study area is proposed.

  12. Paleogene Tectonic Evolution Controls on Sequence Stratigraphic Patterns in the Fushan Sag, Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Guanhong Wang; Hua Wang; Huajun Gan; Entao Liu; Cunyin Xia; Yingdong Zhao; Shanbin Chen; Chengcheng Zhang

    2016-01-01

    Tectonism is of extreme importance to sequence stratigraphic patterns in continental sedimentary basins, affecting both the architectures and internal makeup of sequences. Sequence stratigraphic framework of the Paleogene system in the Fushan sag, northern South China Sea, was built using 3D and 2D seismic data, complemented by drilling cores and well logs data. One first-order, three second-order and seven third-order sequences were identified. Analysis of paleotectonic stress field, unconformities and subsidence history showed that the Paleogene tectonic evolution presented significant characteristics of multistage and episode, and can be divided into three stages: rifting stage I (initial rifting period), rifting stage II (rapid subsidence period), rifting stage III (fault-depressed diver-sionary period). Partition of the west and east in tectonic activity was obvious. The west area showed relatively stronger tectonic activity than the east area, especially during the rifting stage II. Episodic rifting and lateral variations in tectonic activity resulted in a wide variety of structural slope break belts, which controlled both the sequence architectures and interval makeup, and strongly constrained the development of special facies zones or sand bodies that tended to form hydrocarbon accumulation. This paper classifies the genetic types of slope break belts and their relevant sequence stratigraphic patterns within the Fushan sag, and further discusses the tectonic evolution controls on sequence stratigraphic patterns, which suggests that vertical evolution paths of structural slope break belts and relevant sequence stratigraphic patterns as a response to the Paleogene tectonic evolution were strongly controlled by sag margin types and lateral variations of tectonic activity.

  13. Seasonal mesophotic coral bleaching of Stylophora pistillata in the Northern Red Sea.

    Science.gov (United States)

    Nir, Orit; Gruber, David F; Shemesh, Eli; Glasser, Eliezra; Tchernov, Dan

    2014-01-01

    Coral bleaching occurs when environmental stress induces breakdown of the coral-algae symbiosis and the host initiates algae expulsion. Two types of coral bleaching had been thoroughly discussed in the scientific literature; the first is primarily associated with mass coral bleaching events; the second is a seasonal loss of algae and/or pigments. Here, we describe a phenomenon that has been witnessed for repeated summers in the mesophotic zone (40-63 m) in the northern Red Sea: seasonal bleaching and recovery of several hermatypic coral species. In this study, we followed the recurring bleaching process of the common coral Stylophora pistillata. Bleaching occurred from April to September with a 66% decline in chlorophyll a concentration, while recovery began in October. Using aquarium and transplantation experiments, we explored environmental factors such as temperature, photon flux density and heterotrophic food availability. Our experiments and observations did not yield one single factor, alone, responsible for the seasonal bleaching. The dinoflagellate symbionts (of the genus Symbiodinium) in shallow (5 m) Stylophora pistillata were found to have a net photosynthetic rate of 56.98-92.19 µmol O2 cm(-2) day(-1). However, those from mesophotic depth (60 m) during months when they are not bleached are net consumers of oxygen having a net photosynthetic rate between -12.86 - (-10.24) µmol O2 cm(-2) day(-1). But during months when these mesophotic corals are partially-bleached, they yielded higher net production, between -2.83-0.76 µmol O2 cm(-2) day(-1). This study opens research questions as to why mesophotic zooxanthellae are more successfully meeting the corals metabolic requirements when Chl a concentration decreases by over 60% during summer and early fall.

  14. Lithospheric thermal-rheological structures of the continental margin in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Thermal structures of three deep seismic profiles in the continental margin in the northern South China Sea are calculated, their "thermal" lithospheric thicknesses are evaluated based on the basalt dry solidus, and their rheological structures are evaluated with linear frictional failure criterion and power-law creep equation. "Thermal" lithosphere is about 90 km in thickness in shelf area, and thins toward the slope, lowers to 60-65 km in the lower slope, ocean crust and Xisha Trough. In the mid-west of the studied area, the lithospheric rheological structure in shelf area and Xisha Islands is of four layers: brittle, ductile, brittle and ductile. Because of uprising of heat mantle and thinning of crust and lithosphere in Xisha Trough, the bottom of the upper brittle layer is only buried at 16 km. In the eastern area, the bottom of the upper brittle layer in the north is buried at 20 km or so, while in lower slope and ocean crust, the rheological structure is of two layers of brittle and ductile, and crust and uppermost mantle form one whole brittle layer whose bottom is buried at 30-32 km. Analyses show that the characteristics of rheological structure accord with the seismic result observed. The character of rheological stratification implies that before the extension of the continent margin, there likely was a ductile layer in mid-lower crust. The influence of the existence of ductile layer to the evolution of the continent margin and the different extensions of ductile layer and brittle layer should not be overlooked. Its thickness, depth and extent in influencing continent margin's extension and evolution should be well evaluated in building a dynamic model for the area.

  15. Tidal hydrodynamics under future sea level rise and coastal morphology in the Northern Gulf of Mexico

    Science.gov (United States)

    Passeri, Davina L.; Hagen, Scott C.; Plant, Nathaniel G.; Bilskie, Matthew V.; Medeiros, Stephen C.; Alizad, Karim

    2016-05-01

    This study examines the integrated influence of sea level rise (SLR) and future morphology on tidal hydrodynamics along the Northern Gulf of Mexico (NGOM) coast including seven embayments and three ecologically and economically significant estuaries. A large-domain hydrodynamic model was used to simulate astronomic tides for present and future conditions (circa 2050 and 2100). Future conditions were simulated by imposing four SLR scenarios to alter hydrodynamic boundary conditions and updating shoreline position and dune heights using a probabilistic model that is coupled to SLR. Under the highest SLR scenario, tidal amplitudes within the bays increased as much as 67% (10.0 cm) because of increases in the inlet cross-sectional area. Changes in harmonic constituent phases indicated that tidal propagation was faster in the future scenarios within most of the bays. Maximum tidal velocities increased in all of the bays, especially in Grand Bay where velocities doubled under the highest SLR scenario. In addition, the ratio of the maximum flood to maximum ebb velocity decreased in the future scenarios (i.e., currents became more ebb dominant) by as much as 26% and 39% in Weeks Bay and Apalachicola, respectively. In Grand Bay, the flood-ebb ratio increased (i.e., currents became more flood dominant) by 25% under the lower SLR scenarios, but decreased by 16% under the higher SLR as a result of the offshore barrier islands being overtopped, which altered the tidal prism. Results from this study can inform future storm surge and ecological assessments of SLR, and improve monitoring and management decisions within the NGOM.

  16. Carbon fluxes and export in the northern and middle Atlantic Sea measured with drifting sediment traps

    Energy Technology Data Exchange (ETDEWEB)

    Miquel, J-C; Fowler, S; Hamilton, T; Heilmann, J P; LaRosa, J; Carroll, M

    2000-07-26

    In July 1993 and June 1995 drifting sediment traps were deployed near the Po outflow, in the coastal zone and in the Jabuka Pit in order to obtain quantitative information on the vertical flux of particulate material and export of organic carbon in the Northern and Middle Adriatic Sea. During these periods and in July 1994, the standing stock of carbon and nitrogen in the water column were also estimated. Carbon and nitrogen concentrations were higher in the north with a mean of 266 {micro}g C l{sup -1} in surface waters as compared to 92 {micro}g C l{sup -1} in Middle Adriatic; maximum concentrations were associated to the less-saline surface-subsurface waters in the north and to the chlorophyll a maximum in the Middle Adriatic. Organic carbon flux was roughly five times higher near the Po than in the more oligotrophic waters of the central region, with overall values (0.8 to 11.5 mg m{sup -2} d{sup -1}) being low compared to the open Northwestern Mediterranean. Comparison with primary production measurements yielded estimates of carbon export (f-ratio) of 4.7 and 3.4% in the Po and Pit stations, respectively, in 1993 and of 1.6 and 3.6% in the central part of the Adriatic in 1995. These consistently low values suggest enhanced carbon recycling in the upper water column, even in regions characterized by different production and organic flux regimes. Zooplankton fecal pellets were important conveyors of organic carbon in this region; particularly those produced by fishes in the North and coastal sites.

  17. Cold seep status archived in authigenic carbonates: Mineralogical and isotopic evidence from Northern South China Sea

    Science.gov (United States)

    Lu, Yang; Sun, Xiaoming; Lin, Zhiyong; Xu, Li; Gong, Junli; Lu, Hongfeng

    2015-12-01

    Cold-seep carbonates are precipitated under high alkalinity conditions created by the anaerobic oxidation of methane in cold-seep sites. Multiple Ca-Mg-carbonate phases are identified, including aragonite, low-Mg calcite (LMC), high-Mg calcite (HMC), protodolomite, and dolomite. These phases result from different conditions that are related with cold-seep activities. Here, we report on the relationship between the Ca-Mg-carbonate phases and the cold-seep status. Authigenic carbonates were sampled from northern slope of South China Sea. Carbon isotopic compositions of samples from Shenhu area are lower than -40‰, indicating methane-derived carbon. The δ13C values of samples from Southwest (SW) Taiwan area range from ~-30‰ to ~-20‰, which is the result of the mixture of methane carbon and seawater carbon. Carbonate phases were identified according to the composition and structure results. Samples from Shenhu area are composed of protodolomite and HMC. Three zones were discovered from the center to the rim of the cross-section of the tube-like sample from SW Taiwan area. From the external to the internal zones, the carbonate phases are HMC; LMC and protodolomite; HMC, respectively. The intensity of superstructure reflections of the protodolomite from Shenhu area is stronger than that from SW Taiwan area, indicating higher MgCO3 content. Based on the formation conditions of Ca-Mg-carbonates from LMC to dolomite, those with higher MgCO3 content are formed in more active cold-seep environment. According to the distribution of carbonate phases in each sample, the cold seep flux was high in Shenhu area and was sustained for a long time. By contrast, the flux in SW Taiwan area was relatively low and not stable. It once became higher, but finally returned to low.

  18. Pleistocene oceanographie changes indicated by deep sea benthic foraminifera in the northern Indian Ocean

    Science.gov (United States)

    Rai, Ajai K.; Srinivasan, M. S.

    1994-12-01

    An attempt has been made to understand the Pleistocene bottom water history in response to the paleoclimatic changes in the northern Indian Ocean employing quantitative analyses of deep sea benthic foraminifera at the DSDP sites 219 and 238. Among the 150 benthic foraminifera recorded a few species show dominance with changing percent frequencies during most of the sequence. The dominant benthic foraminiferal assemblages suggest that most of the Pleistocene bottom waters at site 219 and Early Pleistocene bottom waters at site 238 are of North Indian Deep Water (NIDW) origin. However, Late Pleistocene assemblage at site 238 appears to be closely associated with a water mass intermediate between North Indian Deep Water (NIDW) and Antarctic Bottom Water (AABW). Uvigerina proboscidea is the most dominant benthic foraminiferal species present during the Pleistocene at both the sites. A marked increase in the relative abundance of U. proboscidea along with less diverse and equitable fauna during Early Pleistocene suggests a relative cooling, an intensified oceanic circulation and upwelling of nutrient rich bottom waters resulting in high surface productivity. At the same time, low sediment accumulation rate during Early Pleistocene reveals increased winnowing of the sediments possibly due to more corrosive and cold bottom waters. The Late Pleistocene in general, is marked by relatively warm and stable bottom waters as reflected by low abundance of U. proboscidea and more diverse and equitable benthic fauna. The lower depth range for the occurrence of Bulimina aculeate in the Indian Ocean is around 2300 m, similar to that of many other areas. B. aculeata also shows marked increase in its abundance near the Pliocene/Pleistocene boundary while a sudden decrease in the relative abundance of Stilostomella lepidula occurs close to the Early/Late Pleistocene boundary.

  19. Metodologija issledovanija mezhdunarodnogo sotrudnichestva po zashhite i ohrane morskoj sredy: opyt regiona Baltijskogo morja dlja severnyh morej [A methodology for research on international cooperation on marine environment protection: application of the Baltic Sea practices to the northern seas

    Directory of Open Access Journals (Sweden)

    Kharlampyeva Nadezhda

    2011-01-01

    Full Text Available This article is dedicated to the methodology for the study of international cooperation on marine environment protection. The author suggests applying the practices of marine environment protection in the Baltic Sea to the northern seas as well as examining earlier projects for the effective implementation of interdisciplinary initiatives bringing together international law, international relations and world politics.

  20. Strontium content in otoliths of common fish species in the northern Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Lill, J-O.; Heselius, S-J. [Accelerator Laboratory, Turku PET Centre, Abo Akademi University, Turku (Finland); Himberg, M.; Hagerstand, H. [Cell Biology, Department of Biosciences, Abo Akademi University, Turku (Finland); Harju, L. [Analytical Chemistry, Department of Chemical Engineering, Abo Akademi University, Turku (Finland); Lindroos, A. [Geology and Mineralogy, Department of Natural Sciences, Abo Akademi University, Turku (Finland); Gunnelius, K.; Smâtt, J-H. [Physical Chemistry, Department of Natural Sciences, Abo Akademi University, Turku (Finland)

    2013-07-01

    Full text: The salinity of water in the northern Baltic Sea forms a gradient as it receives fresh water from several large rivers in the north and salty water by infrequent inflows of North Sea water in the south. The salinity of brackish water in the north-south direction (700 km) changes from about 3 to 7%. In an attempt to use the salinity gradient to study migration patterns, sagittae otoliths were collected from common fish species caught at different locations along the Finnish west coast. Otoliths from fishes caught in fresh-water lakes in Finland and Estonia were also included in the study for comparison. Part of the otoliths was grind and the powder was pressed to pellets which were irradiated in air with an ion beam from the Abo Akademi cyclotron and the emitted X-rays were measured. Other otoliths were embedded in epoxy and polished to reveal the ring structure. These prepared otoliths were irradiated with the ion beam to determine elemental profiles. Furthermore, XRD was applied to study the crystal structure and to identify the minerals in the otoliths. The strontium level of water is usually related to its salinity, and as the strontium ions are able to replace calcium ions in fish otoliths [1], the strontium content in fish otoliths from the same locations is expected to be very similar. However, the PIXE analyses revealed large differences in the strontium content between otoliths from different species of fish caught at the same locations. The strontium concentration in otoliths of perch and pike from the Aland Islands was about 1600 μg/g and of common whitefish 3600 μg/g. The strontium concentration in perch otoliths from the Oravais archipelago, about 400 km north of the Aland Islands, was 1400 μg/g. Corresponding concentration in otoliths of perch and pike caught in fresh-water lakes was 200 μg/g and of common whitefish from Saadjarve 400 μg/g and from Lake Inari 1000 μg/g. Otoliths of perch contained no detectable amounts of zinc (Iower

  1. Late Quaternary climatic forcing on the terrigenous supply in the northern South China Sea: Input from magnetic studies

    Science.gov (United States)

    Chen, Quan; Kissel, Catherine; Liu, Zhifei

    2017-08-01

    The detrital component of marine sediment is a powerful recorder of paleoenvironmental changes in a marginal sea such as the South China Sea. This is in particular valid for the magnetic fraction that is one of the key parameters for paleoenvironmental studies in the South China Sea, although poorly used so far. We report here on the analysis of the magnetic properties of a 50 m-long sedimentary sequence retrieved from the northern South China Sea, on the continental slope off the Pearl River mouth. Magnetic minerals with different coercivities (magnetite, pyrrhotite, and hematite) are mixed. The variations in relative content of these magnetic minerals illustrate influences of various external forcing mechanisms at different timescales. The pyrrhotite content exhibits a long-term increase, which is also observed in illite + chlorite content, indicating a continuous enhancement of supply from Taiwan most likely related to active Taiwan orogeny. Glacial-interglacial fluctuations are characterized by more magnetite and pyrrhotite with coarser silt and magnetic grains during glacials than interglacials. This is attributed to sea-level changes with the enormous continental shelf exposed during glacials, in turn affecting the sediment transport distance and pathway. On a shorter timescale, larger hematite inputs in fine-grained sediments coincide with precession minima. We suggest that this periodic hematite supply change is related to the eolian dust deposited at the studied site in addition to the fluvial and oceanic transported materials.

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

    Science.gov (United States)

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

    2014-02-01

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

  3. Relocation of the Yellow River estuary in 1855 AD recorded in the sediment core from the northern Yellow Sea

    Science.gov (United States)

    Zhou, Xin; Jia, Nan; Cheng, Wenhan; Wang, Yuhong; Sun, Liguang

    2013-12-01

    Relocation of the Yellow River estuary has significant impacts on not only terrestrial environment and human activities, but also sedimentary and ecological environments in coastal seas. The responses of regional geochemical characteristics to the relocation event, however, have not been well studied. In the present study, we performed detailed geochemical elemental analyses of a sediment core from the northern Yellow Sea and studied their geochemical responses to the 1855 AD relocation of the Yellow River estuary. The results show that TOC/TN, Co/Al2O3, Cr/Al2O3, Ni/Al2O3 and Se/Al2O3 ratios all decreased abruptly after 1855 AD, and similar decreases are observed in the sediments of the mud area southwest off the Cheju Island. These abrupt changes are very likely caused by the changes in source materials due to the relocation of the Yellow River estuary from the southern Yellow Sea to the Bohai Sea, which the corresponding decreasing trends caused by the changes in main source materials from those transported by the Liaohe River, the Haihe River and the Luanhe River to those by the Yellow River. Because the events have precise ages recorded in historical archives, these obvious changes in elemental geochemistry of sediments can be used to calibrate age models of related coastal sea sediments.

  4. On measurements of aerosol-gas composition of the atmosphere during two expeditions in 2013 along Northern Sea Route

    Science.gov (United States)

    Sakerin, S. M.; Bobrikov, A. A.; Bukin, O. A.; Golobokova, L. P.; Pol'kin, Vas. V.; Pol'kin, Vik. V.; Shmirko, K. A.; Kabanov, D. M.; Khodzher, T. V.; Pavlov, A. N.; Potemkin, V. L.; Radionov, V. F.

    2015-06-01

    We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in water basins of Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August-22 September 2013) and RV Professor Khljustin (24 July-7 September 2013). The specific features of spatial distribution and time variations of aerosol optical depth (AOD) of the atmosphere in the wavelength range of 0.34-2.14 μm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov) there is a decrease in aerosol and black carbon concentrations in northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 μm) values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m-3, respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from Japan to Chukchi Sea, the aerosol number concentration decreased, on the average, from 23.7 to 2.5 cm-3, the black carbon mass concentration decreased from 150 to 50 ng m-3, and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at latitude of ∼ 55° N. For water basins of eight seas, we present the chemical compositions of water-soluble aerosol fraction (ions, elements) and small gaseous impurities, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75-89 %) supplied from the atmosphere to the sea surface

  5. On measurements of aerosol–gas composition of the atmosphere during two expeditions in 2013 along Northern Sea Route

    Directory of Open Access Journals (Sweden)

    S. M. Sakerin

    2015-06-01

    Full Text Available We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in water basins of Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August–22 September 2013 and RV Professor Khljustin (24 July–7 September 2013. The specific features of spatial distribution and time variations of aerosol optical depth (AOD of the atmosphere in the wavelength range of 0.34–2.14 μm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov there is a decrease in aerosol and black carbon concentrations in northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 μm values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m-3, respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from Japan to Chukchi Sea, the aerosol number concentration decreased, on the average, from 23.7 to 2.5 cm-3, the black carbon mass concentration decreased from 150 to 50 ng m-3, and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at latitude of ∼ 55° N. For water basins of eight seas, we present the chemical compositions of water-soluble aerosol fraction (ions, elements and small gaseous impurities, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75–89 % supplied from the atmosphere to

  6. A last glacial and deglacial pollen record from the northern South China Sea: New insight into coastal-shelf paleoenvironment

    Science.gov (United States)

    Yu, Shaohua; Zheng, Zhuo; Chen, Fang; Jing, Xia; Kershaw, Peter; Moss, Patrick; Peng, Xuechao; Zhang, Xin; Chen, Chixin; Zhou, Yang; Huang, Kangyou; Gan, Huayang

    2017-02-01

    This study presents a marine palynological record of the Asian summer monsoon and sea level change in the Last Glacial Maximum (LGM) and the deglacial period in the northern South China Sea (SCS). A fossil core STD 235 (855 cm in length) and 273 surface sediment samples from the northern SCS were pollen analysed to reconstruct the paleoenvironment of the continental shelf during the last glacial period. Results from fossil pollen show that the main pollen source region fundamentally changed from the LGM to the deglacial period as sea level rapidly rose. The modern marine surface samples show that pollen concentrations in the estuary of the Pearl River are extremely high, and modern pollen assemblages are in good agreement with the regional vegetation. However, wind transport becomes more important in the deeper ocean as the percentages of Pinus, a taxon with very high pollen production and dispersal capacity, is highest in these sediments, which otherwise have very low pollen concentrations. The concentration of total pollen between surface and fossil pollen samples is compared in order to determine the possible vegetation sources areas for the marine core. Pollen concentration as high as >100 grains/g at the LGM suggested that the paleo-shoreline was located within 80 km of the core. Consequently, pollen would mostly have derived from the exposed continental shelf in the northern SCS. By contrast, pollen concentrations were very low due to a much greater transport distance (318 km at present, core STD 235) under higher sea levels, and windblown pollen played a more important role because of the limitation of riverine input into the deep ocean during this highstand period. Such alternation of pollen flux and source distance should be repeated during all glacial-interglacial cycles, reflecting closely sea level and climate dynamics. According to fossil pollen assemblages from Core STD 235, we conclude that wetland and/or grassland communities with sparse subtropical

  7. Jurassic and Cretaceous clays of the northern and central North Sea hydrocarbon reservoirs reviewed

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M.; Haszeldine, R.S.; Fallick, A.E.

    2006-03-15

    The principal clays of the northern and central North Sea are illite (sometimes with interlayered smectite) and kaolin. Chlorite is only locally important. Although it has been proposed that kaolin within North Sea sandstones is detrital in origin, the majority of workers have concluded that it is authigenic, largely the product of feldspar alteration. Kaolin is found within a wide range of sedimentary settings (and within shales) apparently defying the notion that kaolin is an indicator of meteoric water deposition. Within sandstones, the earliest authigenic kaolin has a vermiform morphology, the distribution of which is controlled by the availability of detrital mica to act as a nucleus, and the composition of the post-depositional porewaters. This vermiform kaolin formed in meteoric water, the presence of which is easily accounted for below sub-aerial exposure surfaces in non-marine formations, and below unconformities over marine units. In fully marine sands, and even marine shale units, kaolin still occurs. It has therefore been suggested that even these locations have been flushed with meteoric water. Early vermiform kaolin recrystallizes to a more blocky morphology as burial proceeds, at least in the Brent Group. Blocky kaolin has been reported as growing before, synchronously with, and after the formation of quartz overgrowths, though oxygen isotope studies support low-temperature growth, pre-quartz. Blocky kaolin may form during meteoric flushing associated with lower Cretaceous uplift and erosion, though it is found in fault blocks that are thought to have remained below sea level. Here, the kaolin may form in stagnant meteoric water, relics of the post-depositional porewater. It has also been proposed that the blocky kaolin grew in ascending basinal waters charged with carboxylic acids and CO{sub 2}, though this hypothesis is not supported by stable oxygen isotope data. Some of the blocky kaolin is dickite, the stable polymorph above 100{sup o}C. Fibrous

  8. 1991 Pinatubo, Philippines Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mount Pinatubo is an andesitic island arc volcano, located on the southwestern part of the island of Luzon in the Philippines. Prior to 1991, it had been dormant for...

  9. Vertical characteristics revealed by biweekly and synoptic variability of upper sea temperature in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yani; ZHOU Faxiu; HUANG Fei

    2005-01-01

    On the basis of the analysis of the sea temperature data that are observed from the three automatic temperature line acquisition sysem mooring buoys deployed in the central South China Sea (SCS) during South China Sea monsoon experiment, vertical features of biweekly and synoptic variability are discussed. There are five vertical modes, that is, subsurface temperature variability is in phase with,out of phase with, leads to, lags the surface temperature variability, and at depths within the subsurface layer the upper and lower temperature variations are out of phase. The formation of these vertical modes is related to the property of low-level atmospheric forcing and to the background in atmosphere and ocean. Wind stress curl is the main driving factor in forming Modes 1 and 3, and wind stresses in forming Modes 2 and 4.

  10. Rapid post-rift tectonic subsidence events in the Pearl River Mouth Basin, northern South China Sea margin

    Science.gov (United States)

    He, Min; Zhong, Guangfa; Liu, Xuefeng; Liu, Lihua; Shen, Xinping; Wu, Zhe; Huang, Ke

    2017-10-01

    Data from 26 drill wells and 27 regional seismic profiles were integrated to investigate the timing, phase and origin of the post-rift subsidence in the middle to eastern Pearl River Mouth Basin (PRMB) of the northern South China Sea using the traditional 1-D backstripping technique. Different from previous research of backstripped tectonic subsidence in the basin, we calculated the tectonic subsidence using the newly built local porosity-depth relationships for decompaction and updated sedimentological and paleontological data for paleobathymetry reconstruction. Well-data based subsidence curves reveal a roughly decaying pattern in both the magnitude and rate of the post-rift subsidence in the PRMB, which is in accordance with the general decreasing trend of the thermal subsidence typical of a passive margin. Two events of rapid post-rift tectonic subsidence were identified, which occurred in the Early to early Middle Miocene and the Pliocene. The timing of the first rapid post-rift subsidence event varies and is earlier in the southern rather than northern part of the basin. Additionally, the amplitude of contemporaneous tectonic subsidence is greater in the southern part of the basin. The second rapid tectonic subsidence event occurred simultaneously in both the southern and northern parts of the basin, with the amplitude of subsidence being much greater in the southern part. We associate the first rapid subsidence event with the southward jump of the South China Sea spreading ridge, which occurred between the Oligocene and Early Miocene, while the second event with the arc-continent collision at Taiwan since the latest Late Miocene. The southern PRMB in the deep-water slope area shows a much higher magnitude of tectonic subsidence in both events than its northern counterpart in the shelf area, which could be associated with its much thinner lithosphere. The latter could cause upswelling of denser lower crust and upper mantle material, resulting in more rapid

  11. Evaluating the effects of protection on fish predators and sea urchins in shallow artificial rocky habitats: a case study in the northern Adriatic Sea.

    Science.gov (United States)

    Guidetti, P; Bussotti, S; Boero, F

    2005-05-01

    Man-made defence structures (e.g., breakwaters, jetties) are becoming common features of marine coastal landscapes all around the world. The ecology of assemblages of species associated with such artificial structures is, however, poorly known. In this study, we evaluated the density and size of fish predators of echinoids (i.e., Diplodus sargus, Diplodus vulgaris, Sparus aurata), and the density of sea urchins (i.e., Paracentrotus lividus) at defence structures (i.e., breakwaters) inside and outside the marine protected area of Miramare (northern Adriatic Sea) in order to: (1) assess possible differences in fish predator density and size between protected and fished breakwaters; (2) assess whether fish predation may have the potential to affect sea urchin density in artificial rocky habitats. Surveys were carried out at four random times over a period of two years. Total density, and density of medium- and large-sized individuals of the three predatory fishes were generally greater at the protected than at the fished breakwaters, whereas no differences were detected in the density of small-sized individuals. Density of the sea urchin P. lividus did not show any difference between protected and fished breakwaters. The results of this study suggest that: (1) protection may significantly affect predatory fishes in artificial rocky habitats; (2) differences in predatory fish density, and size may be unrelated with the density of the sea urchin P. lividus; (3) protected artificial structures such as breakwaters, originally planned for other purposes, could represent a potential tool for fish population recovery and enhancement of local fisheries.

  12. Paleoceanographic records and sea ice extension history on the slope of the northern Bering Sea over the last 100 ka B.P.

    Institute of Scientific and Technical Information of China (English)

    WANG Rujian; LI Xia; XIAO Wenshen; XIA Peifen; CHEN Ronghua

    2005-01-01

    Quantitative analytic results of the biogenic components in Core B2-9 from the northern Bering Sea slope indicate that the coarse fraction and opal content, serving as proxies of surface productivity, have increased stepwise since the marine isotope stage(MIS)5.3, reflecting periodic enhancement in surface productivity. The surface productivity attained its highest level during the Holocene, followed by MIS 3.2 to 2 and then MIS 5.3 to 3.3 with a lowest level. High total organic carbon(TOC) contents, together with high C/N ratios,which stand mostly between 7 and 20, show that the TOC was deposited from mixing sources. Therefore,one has to be cautious to use TOC as a proxy of surface productivity. The high TOC and C/N ratio during MIS 5.1, 3.3 to 3.2 and the Holocene reflect that the terrigenous organic matter input increased during interglacial periods. Increases in the fine- and silt-grained terrigenous components from MIS 5.3 to the middle Holocene imply that with the cooling climate, sea ice on the Bering Sea slope extended continuously. Ice-rafted and charcoal detritus increased during glacial, interstadial and the last deglaciation periods and decreased during interglacial periods,suggesting that sea ice on the slope increased and melted, respectively, during glacial and interglacial periods. The extension of sea ice during glacial periods,which was linked with the climate over the North American Continent, responded to global climate change during late Quaternary glacial and interglacial cycles.

  13. Size-fractionated Chlorophyll a biomass in the northern South China Sea in summer 2014

    Science.gov (United States)

    Liu, Haijiao; Xue, Bing; Feng, Yuanyuan; Zhang, Rui; Chen, Mianrun; Sun, Jun

    2016-07-01

    Spatial distribution of phaeopigment and size-fractionated chlorophyll a (Chl a) concentrations were examined in relation to hydrographic conditions in the northern South China Sea (NSCS) during a survey from 20 August to 12 September, 2014. The total Chl a concentration varied from 0.006 to 1.488 µg/L with a mean value of 0.259±0.247 (mean±standard deviation) µg/L. Chl a concentration was generally higher in shallow water (200 m), with mean values of 0.364±0.311 µg/L and 0.206±0.192 µg/L respectively. Vertically, the maximum total Chl a concentration appeared at depths of 30-50 m and gradually decreased below 100 m. The size-fractionated Chl a concentrations of grid stations and time-series stations (SEATS and J4) were determined, with values of pico- (0.7-2 µm), nano- (2-20 µm) and micro-plankton (20-200 µm) ranging from 0.001-0.287 (0.093±0.071 µg/L), 0.004-1.149 (0.148±0.192 µg/L) and 0.001-0.208 (0.023±0.036 µg/L), respectively. Phaeopigment concentrations were determined at specific depths at ten stations, except for at station A9, and varied from 0.007 to 0.572 (0.127±0.164) µg/L. Nano-and pico-plankton were the major contributors to total phytoplankton biomass, accounting for 50.99%±15.01% and 39.30%±15.41%, respectively, whereas microplankton only accounted for 9.39%±8.66%. The results indicate that the contributions of microplankton to total Chl a biomass were less important than picoplankton or nanoplankton in the surveyed NSCS. Different sized-Chl a had similar spatial patterns, with peak values all observed in subsurface waters (30-50 m). The summer monsoon, Kuroshio waters, Zhujiang (Pearl) River plume, and hydrological conditions are speculated to be the factors controlling the abundance and spatial heterogeneity of Chl a biomass in the NSCS.

  14. Succession of free-living and particle associated prokaryotes in the northern Adriatic Sea

    Science.gov (United States)

    Steiner, P. A.; Ivančić, I.; Paliaga, P.; Matošović, K.; Haberleitner, E.; Sintes, E.; Najdek, M.; Herndl, G. J.

    2016-02-01

    Marine snow is composed of a complex pool of organic and inorganic matter. Microbial communities thrive in it, using a large number of compounds as a source of energy and nutrients. Microbial abundance and activity have been reported to be orders of magnitude higher in marine snow than in the ambient water. However, it is still unclear whether the microbial community colonizing marine snow comprises mainly generalists or specialists. In this study, we monitored the prokaryotic community inhabiting marine snow (MS) and ambient water (AW) in the northern Adriatic Sea. MS was collected with syringes during SCUBA diving and AW was sampled with Niskin bottles. In the AW, inorganic N:P ratios averaged 30.5 ± 24.8 indicating P-limitation while in MS inorganic N:P ratios were 11 ± 11.9. Prokaryotic abundance in MS was similar to AW, with an enrichment factor (EF, i.e. ratio between MS/AW) of 1.4 ± 1.8. However, the microbial activity was generally higher in MS, extracellular enzymatic activity exhibited EFs ranging from 2.6 ± 1.4 to 8.3 ± 7.7, and the EF of heterotrophic leucine incorporation, a proxy for heterotrophic biomass production, was 7.8 ± 4.9. The relative abundance of different phylogenetic groups in MS changed over the course of the summer, e.g. Sphingobacteriales (from 10.6% to 0.9%), Verrucomicrobia (0.3% to 3.5%) and Actinobacteria (1.2% to 5.5%), indicating successional changes linked to changes in the environmental conditions in MS. The bacterial community inhabiting MS was characterized by a larger relative abundance of Cyanobacteria as compared to AW (27.5% in MS vs. 13.5% in AW) and Planctomycetes (4.8% in MS vs. 1.1% in AW) and a lower abundance of Alphaproteobacteria (20% in MS vs. 38.5% in AW). Taken together, our results indicate the presence of a core bacterial community in MS and AW. The highly active MS community is characterized by the presence of specialized groups that can reach high abundances, and a dynamic generalist community

  15. Nitrogen production in the northern Arabian Sea during the Spring Intermonsoon and Southwest Monsoon seasons

    Science.gov (United States)

    Sambrotto, Raymond N.

    Planktonic nitrogen productivity and regeneration were measured with 15NO 3, 15NH 4 and 15N-urea tracers during the Spring Intermonsoon (SI) and Southwest Monsoon (SWM) seasons in the northern Arabian Sea from the Omani coast southeast to 10°N. On an areal basis, new (nitrate) productivity and the nitrogen f-ratio varied from 0.1 to 13 mmol m -2 d -1 and 0.03 to 0.4, respectively. Including urea in total nitrogen uptake lowered the f-ratio by 29% on average for individual samples, and during the SI was most important in offshore regions. The lowest nitrate productivity rates also were measured in offshore regions during the SI, where low, but detectable, nitrate levels limited uptake. The onset of the SWM was associated with an order of magnitude increase in nitrate uptake seaward of the Findlater Jet as compared to the SI. Apparently, the positive effect of the increased availability of nitrate and the Ekman transport of established phytoplankton populations to the region more than offset the degraded light conditions caused by the deep (>80 m) mixed layers. Despite the increases in offshore nitrate uptake, both a budget of surface particulate material and 234Th POC flux estimates indicated that the mid- SWM reduced the efficiency of material export from surface waters and disrupted the linkage between new production and export that was evident in the SI. In the mid-SWM, new production mainly accumulated in deeply mixed surface waters offshore, and may be responsible for the well documented lag between the onset of the SWM and export. In the coastal upwelling region, new production rates were significantly greater during the SWM only near filaments of coastal water advected offshore. Ammonium regeneration rates and concentrations increased significantly in coastal regions during the SWM, and nitrification likely was a significant sink for some of the ammonium produced there. The transport of some of the remainder of this reduced nitrogen offshore would fuel

  16. Long term changes in the ecosystem in the northern South China Sea during 1976–2004

    Directory of Open Access Journals (Sweden)

    X. Ning

    2008-09-01

    Full Text Available Physical and chemical oceanographic data were obtained by seasonal monitoring along Transect N in the northern South China Sea (nSCS during 1976–2004. Fluctuations of DIN (dissolved inorganic nitrogen, seawater temperature (SST and Tav – average temperature of the water column, N:P ratio and salinity (Sav and S200 – salinity at the 200 m layer exhibited an increasing trend, while those of T200, DO, P, Si, Si:N and SSS exhibited a decreasing trend. The annual rates of change in DIN, DO, T and S revealed pronounced changes, and the climate trend coefficients Rxt, which was defined as the correlation coefficient between the time series of an environmental parameter and the nature number, were 0.38 to 0.89 and significant (p≤0.01 to 0.05. Our results also showed that the ecosystem has obviously been influenced by the positive trends of both SST and DIN, and negative trends of both DO and P, e.g. before 1997, DIN concentrations in the upper layer were very low and N:P ratios were less than half of the Redfield ratio of 16, indicating potential N limitation. However, after 1997, all Si:P ratios were >22 and the Nav:Pav was close to the Redfield ratio, indicating potential P limitation, and therefore N limitation has been reduced after 1997.

    Ecological investigation shows that there have been some improved responses of the ecosystems to the long-term environmental changes in the nSCS, and chlorophyll-a concentration, primary production, phytoplankton abundance, benthic biomass, cephalopod catch and demersal trawl catch have increased. But phosphorus depletion in upper layer may be related to the shift in the dominant species from diatoms to dinoflagellates and cyanophytes. The ecosystem response was induced by not only anthropogenic activities, but also global climate change, e.g. pronounced

  17. Vertical Structure of Baroclinic Currents over Northern South China Sea Continental Slope

    Institute of Scientific and Technical Information of China (English)

    邱章

    2001-01-01

    The 28.6 d time series of ADCP currents at 27 depth levels, (11,15,…,115m) which are obtained from a mooring station at the northern South China Sea continental slope, have been decomposed into barotropic and baroclinic components. The emphasis in this paper is on the analysis of the time series of baroclinic currents by means of several methods,such as the tidal harmonic analysis, the power spectra and the kinetic energy estimation.The major results are as follows: (1) In respect of the baroclinic currents, the values of several parameters first decrease and then increase with depth. These parameters include the temporal mean value of the cross-shelf component, the standard deviations, the amplitudes of K1 constituents, the mean eddy kinetic energy, as well as the significant peaks of the power spectra of the cross-shelf components. (2) The diurnal period of the baroclinic currents is dominant. The diumal tidal current rotates clockwise and the major axis of current ellipse is located along the directions of NW-SE. The vertical distribution of the phases of the diurnal constituent varies with the different water layers. Around the 67m depth level, the phase changes very much.At those layers far away from the 67m depth level, the vertical distribution of the phase is relatively stable, but with opposite phases in the upper and lower water layers. For the upper layers between the surface and 67m,the phases are around 300°; for the lower layers between 67m and 115m, the phases are around 120° .(3) The mean eddy kinetic energy of the baroclinic current is quite large, accounting for 41% of the mean kinetic energy of the measured currents. The cross-shelf component is larger than the along-shelf one. The two baroclinic current components correspond to the major and minor axes of the current ellipse of the diurnal constituent respectively. (4) The power spectra of the baroclinic currents show a singnificant period of about 24h, with 23.6h at both 19m and 99m and 24

  18. The sedimentary regime around northern Sylt, South-eastern North Sea, based on shallow seismic (sparker and Chirp III) information

    DEFF Research Database (Denmark)

    Boldreel, Lars Ole; Kuijpers, Antoon; Madsen, Emil B

    2010-01-01

    The coastal off-shore zone of the northern part of the island of Sylt was investigated by sparker seismics and high-resolution subbottom profiling during the period 2005-2009. The data was acquired in the North Sea sector as well as in the Lister Tief, Lister Ley, Højer Dyb and Rømø Dyb. During...... characteristics, the areal distribution of ebb-, flood- and indefinite dunes and erosion scars has been documented. The interpreted data are complementary to information from sidescan sonar data acquired within the framework of our study and by others. In addition, our data set provides new, subbottom information...

  19. A new genus and species of Thyasiridae (Mollusca, Bivalvia from deep-water, Beaufort Sea, northern Alaska

    Directory of Open Access Journals (Sweden)

    Paul Valentich-Scott

    2014-12-01

    Full Text Available Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds.

  20. Serologic evidence of influenza A(H1N1)pdm09 virus in northern sea otters

    Science.gov (United States)

    Li, Zhu-Nan; Ip, Hon S.; Frost, Jessica F.; White, C. LeAnn; Murray, Michael J.; Carney, Paul J.; Sun, Xiang-Jie; Stevens, James; Levine, Min Z.; Katz, Jacqueline M.

    2014-01-01

    Sporadic epizootics of pneumonia among marine mammals have been associated with multiple animal-origin influenza A virus subtypes (1–6); seals are the only known nonhuman host for influenza B viruses (7). Recently, we reported serologic evidence of influenza A virus infection in free-ranging northern sea otters (Enhydra lutris kenyoni) captured off the coast of Washington, USA, in August 2011 (8). To investigate further which influenza A virus subtype infected these otters, we tested serum samples from these otters by ELISA for antibody-binding activity against 12 recombinant hemagglutinins (rHAs) from 7 influenza A hemagglutinin (HA) subtypes and 2 lineages of influenza B virus (Technical Appendix Table 1). Estimated ages for the otters were 2–19 years (Technical Appendix Table 2); we also tested archived serum samples from sea otters of similar ages collected from a study conducted during 2001–2002 along the Washington coast (9).

  1. Length-weight relationship of eleven species of marine catfishes from the northern Arabian Sea coast of Pakistan

    Science.gov (United States)

    Farooq, Noureen; Qamar, Nazia; Rashid, Shahnaz; Panhwar, Sher Khan

    2016-10-01

    This study records length-weight relationships (LWRs) for eleven commercially important marine catfish species of the family Ariidae (sea catfishes) and Plotosidae (eel catfishes) from the northern Arabian Sea coast of Pakistan. The specimens were sampled from December 2014 to November 2015, using bottom trawls with various mesh sizes by commercial vessels. The species were Nemapteryx caelatus, Sciades sona, Arius gagora, Batrachocephalus mino, Netuma thalassina, N. bilineata, Osteogeneiosus militaris, Plicofollis dussumieri, P. tenuispinis, Plotosus limbatus, and P. lineatus. Of the eleven species, two species A. gagora and N. bilineata were recorded for the first time and LWRs for four species A. gagora, N. bilineata, S. sona, and B. mino still have no data in the FishBase database. In addition, new maximum length for each of the three species N. bilineata, O. militaris and B. mino was also found.

  2. 4-m Image of the Northern Half of the Backscatter Intensity Mosaic of the Sea Floor off Northeastern Cape Cod from USGS Cruise 98015 (CAPENORTHMOS_GEO4M_WGS84.TIF, Geographic, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set includes backscatter intensity of the sea floor offshore of northern Cape Cod, Massachusetts. The data were collected with a multibeam sea floor...

  3. 4-m Image of the Northern Half of the Backscatter Intensity Mosaic of the Sea Floor off Northeastern Cape Cod from USGS Cruise 98015 (CAPENORTHMOS_GEO4M_WGS84.TIF, Geographic, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set includes backscatter intensity of the sea floor offshore of northern Cape Cod, Massachusetts. The data were collected with a multibeam sea floor...

  4. Characterization of the northern Red Sea's oceanic features with remote sensing data and outputs from a global circulation model

    Directory of Open Access Journals (Sweden)

    Ahmed Eladawy

    2017-07-01

    Full Text Available Sea surface temperature (SST and surface wind (SW are considered the most important components in air–sea interactions. This study examines the relationships between SST, SW and various oceanic variables in the northern Red Sea (NRS during the period of 2000–2014. The current study is the first attempt to identify the SST fronts and their relationship with the dominant circulation patterns. SST fronts are mapped using the Cayula and Cornillon algorithms. The analysis is performed with available remote sensing and reanalyzed data together with 1/12° HYbrid Coordinate Ocean Model (HYCOM outputs. Seasonal-trend decomposition procedure based on loess (STL is applied for trend analysis, and Principal Component Analysis (PCA is run for the atmospheric parameters. The SST, SW speed and Chlorophyll-a (Chl-a changes show insignificant trends during the period of 2000–2014. Meridional SST fronts are more significant during the month of January, and fronts that are perpendicular to the sea's axis occur from February to May. Distinct monthly and spatial variations are present in all the examined parameters, although these variations are less pronounced for the wind direction. The SST is mainly controlled by the air temperature and sea level pressure. Significant correlations exist between the SST and the studied parameters (alongshore wind stress rather than the cross-shore wind stress, surface circulation, MLD, and Chl-a. Surface winds generally flow southeastward parallel to the Red Sea's axis explaining that alongshore wind stress is highly correlated with the studied parameters.

  5. Extent of the northern Baltic Sea during the Early Palaeozoic Era – new evidence from Ostrobothnia, western Finland

    Directory of Open Access Journals (Sweden)

    Uutela, A.

    1998-12-01

    Full Text Available This study reports new evidence of the extent of the northern Baltic Sea during the Cambrian and Ordovician periods. A drillcore (DC304 from the Lappajärvi impact crater, western Finland, and erratics from the surrounding area were studied for acritarchs. The acritarchs from the drillcore were reworked by the explosion but indicate, however, that the Baltic Sea extended beyond the western coast of central Finland during the Lower Cambrian Vergale and the Middle Cambrian Kibartai regional stages as well as during Middle Ordovician transitions from Aseri to Lasnamägi and from Idavere to Jöhvi regional stages. The provenance of the erratics was the Bothnian Bay, further north than the Lower Palaeozoic deposits previously known in the Bothnian Sea. The age could be determinated by their acritarch composition which shows that the sea also covered Central Ostrobothnia during the Lower Ordovician Billingen and early Middle Ordovician Lasnamägi regional stages. The drillcore samples contained also unknown spores. They suggest that there have been sediments and/or a terrestrial flora later than Ordovician in the Lappajärvi area.

  6. Microbial control of silver mineralization at a sea-floor hydrothermal site on the northern Gorda Ridge

    Science.gov (United States)

    Zierenberg, R.A.; Schiffman, P.

    1990-01-01

    THE Sea Cliff hydrothermal field, on the northern Gorda Ridge, contains mounds and chimneys of hydrothermally precipitated sulphide and sulphate minerals typical of sea-floor hydrothermal vent sites1. In addition, large areas of the sea floor are covered by subhorizontal hydrothermal crusts. Samples of the crust recovered by submersible are composed of intensely altered fragments of basalt and basaltic hyaloclastite cemented by amorphous silica and chalcedony with less abundant barite, and minor amounts of base-metal sulphide minerals2. Some surfaces of the crust were formerly colonized by bacterial mats, which are locally preserved by replacement and overgrowth of the bacterial filaments by metal sulphide minerals and amorphous silica. The bacterial filaments are selectively replaced by prousite (Ag3AsS3), pearceite3 (Ag14.7-XCu1.3+xAs2S11), chalcopyrite (CuFeS2) and rarely by galena (PbS). Our observations suggest that bacterially mediated processes selectively precipitate silver, arsenic and copper, and that biological processes may contribute to precious-metal enrichment in some sea-floor hydrothermal base-metal sulphide deposits.

  7. Sea-salt aerosol transport patterns over the Northern Hemisphere inferred from two subarctic ice core records

    Institute of Scientific and Technical Information of China (English)

    YAN Yuping; KANG Shichang; SUN Junying; Paul A. Mayewski; QIN Dahe

    2005-01-01

    Atmospheric circulation reconstruction based on glaciochemical records requires knowledge of chemical concentration controls, such as source, transport pathway and strength. To gain insight into these processes, the relationships between glaciochemical records from two Northern Hemisphere sites (Mt. Logan in Yukon Territory and 20D in southern Greenland) and instrumental sea level pressure (SLP) series are investigated. Calibrations between Mt. Logan sea-salt sodium (ssNa+) concentration and SLP series show that ssNa+ concentrations are closely correlated with the autumntime (SON) Aleutian Low and the summertime (JJA) North Pacific Subtropical High. Both the deepened Aleutian Low and enhanced North Pacific Subtropical High strengthen the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. Calibrations between 20D ssNa+ concentrations and SLP series indicate that ssNa+ concentrations are closely related to the wintertime (Jan.) Icelandic Low. A deepening of the Icelandic Low strengthens winter storms and frequent cyclogenesis over the North Atlantic and pushes more sea-salt laden air masses to the Greenland ice sheet. Therefore, ice core ssNa+ records from the Mt. Logan region can be considered as a proxy for reconstructing the autumntime Aleutian Low and summertime North Pacific Subtropical High, and the ssNa+ records from Greenland ice core (20D) may provide a proxy for reconstructing the wintertime Icelandic Low.

  8. Respective roles of direct GHG radiative forcing and induced Arctic sea ice loss on the Northern Hemisphere atmospheric circulation

    Science.gov (United States)

    Oudar, Thomas; Sanchez-Gomez, Emilia; Chauvin, Fabrice; Cattiaux, Julien; Terray, Laurent; Cassou, Christophe

    2017-02-01

    The large-scale and synoptic-scale Northern Hemisphere atmospheric circulation responses to projected late twenty-first century Arctic sea ice decline induced by increasing Greenhouse Gases (GHGs) concentrations are investigated using the CNRM-CM5 coupled model. An original protocol, based on a flux correction technique, allows isolating the respective roles of GHG direct radiative effect and induced Arctic sea ice loss under RCP8.5 scenario. In winter, the surface atmospheric response clearly exhibits opposing effects between GHGs increase and Arctic sea ice loss, leading to no significant pattern in the total response (particularly in the North Atlantic region). An analysis based on Eady growth rate shows that Arctic sea ice loss drives the weakening in the low-level meridional temperature gradient, causing a general decrease of the baroclinicity in the mid and high latitudes, whereas the direct impact of GHGs increase is more located in the mid-to-high troposphere. Changes in the flow waviness, evaluated from sinuosity and blocking frequency metrics, are found to be small relative to inter-annual variability.

  9. Northern Arabian Sea Circulation - Autonomous Research: Optimal Planning Systems (NASCar-OPS)

    Science.gov (United States)

    2015-09-30

    Optimal Planning Systems (NASCar-OPS) Dr. Pierre F.J. Lermusiaux Department of Mechanical Engineering Center for Ocean Science and Engineering... system design and for adaptive sampling during sea operations , using advanced Bayesian information theoretic approaches - Improve the understanding of...modeling, both for real-time sea operations and for optimized re-analyses - Collaborate and transfer data, expertise, approaches, algorithms and

  10. Rising methane emissions from northern wetlands associated with sea ice decline

    DEFF Research Database (Denmark)

    Parmentier, Frans Jan W; Zhang, Wenxin; Mi, Yanjiao

    2015-01-01

    . Nonetheless, terrestrial and marine environments are seldom jointly analyzed. By comparing satellite observations of Arctic sea ice concentrations to methane emissions simulated by three process-based biogeochemical models, this study shows that rising wetland methane emissions are associated with sea ice...

  11. Rising methane emissions from northern wetlands associated with sea ice decline

    DEFF Research Database (Denmark)

    Parmentier, Frans-Jan; Zhang, Wenxin; Mi, Yanjiao;

    2015-01-01

    The Arctic is rapidly transitioning toward a seasonal sea ice-free state, perhaps one of the most apparent examples of climate change in the world. This dramatic change has numerous consequences, including a large increase in air temperatures, which in turn may affect terrestrial methane emissions....... Nonetheless, terrestrial and marine environments are seldom jointly analyzed. By comparing satellite observations of Arctic sea ice concentrations to methane emissions simulated by three process-based biogeochemical models, this study shows that rising wetland methane emissions are associated with sea ice...... retreat. Our analyses indicate that simulated high-latitude emissions for 2005–2010 were, on average, 1.7 Tg CH4 yr−1 higher compared to 1981–1990 due to a sea ice-induced, autumn-focused, warming. Since these results suggest a continued rise in methane emissions with future sea ice decline, observation...

  12. Food Habits and Distribution of the Lake Taal Sea Snake (Hydrophis semperi Garman 1881) and the Sympatric Little File Snake (Acrochordus granulatus Schneider 1799) in Lake Taal, Philippines

    Institute of Scientific and Technical Information of China (English)

    Vhon Oliver S GARCIA; Rey Donne S PAPA; Jonathan Carlo A BRIONES; Norman MENDOZA; Noboru OKUDA; Arvin C DIESMOS

    2014-01-01

    Our knowledge about the food habits of sea snakes and how it is associated with their distribution has seen much development through its description across a number of species available through published literature except for the key threatened species such asHydrophis semperi. This paper aims to describe the food habits ofH. semperi through gut content and stable isotope analyses. We also compared data with the Little File Snake,Acrochordus granulatus, sympatric withH. semperi.Recorded captures ofH. semperi suggest that the sea snake tends to occur in the littoral zones and the shallower portions of the limnetic zone. Gut content analysis ofH. semperi have shown that gobies and eels are primary prey items. Halfbeaks (Family Hemiramphidae) were recorded as one of the Lake Taal Sea Snake’s prey items which is considered as a new prey record for sea snakes. These extracted gut contents are conifrmed to be the temporal food preference ofH. semperi given our detected stable isotope signatures. It appears thatA. granulatus and H. semperi share common prey items suggesting possible diet overlap and resource competition.This study reports the ifrst account of the endemic Lake Taal Sea Snake’s distribution and food habits which poses implications towards its conservation as it occurs in a restricted ecosystem that has undergone considerable habitat alteration.

  13. The effects of petroleum activity in the Northern areas. Northern Sea, Jan Mayen and the Barents sea; Ringvirkninger av petroleumsaktivitet i nordomraader. Norskehavet, Jan Mayen og Barentshavet

    Energy Technology Data Exchange (ETDEWEB)

    Eika, Torbjoern; Prestmo, Joakim; Cappelen, Aadne

    2012-11-15

    The effects of petroleum activity respectively in the north-eastern Norwegian Sea,Barents Sea south-east and around Jan Mayen are not likely to be very large in a national context, but clearly noticeable. The calculations show the effects of activity in the relevant area, compared to a situation where this activity is not initiated. This can be considered as a study of how the Norwegian economy is affected by a decision to start exploration, followed by developing of the economically viable discoveries. Fiscal policy is assumed unaffected. It is thus not taken into account how the different scenarios will affect the pension fund and thus the frames for oil spending resulting from the fiscal rule. The effects we study are the direct employment in the petroleum sector that can be expected, and the effects of the demand in the form of capital goods and intermediate input. Uncertainty is discussed for each area in terms of alternative scenarios of relatively high and relatively low quantities of petroleum resources. The impact on the economy is clearly most significant in the development phase. This is because the demand related to exploration and operation phases are much more modest. The effects during the production phase are dampened by the weakened cost competitiveness as results of higher level of activity in previous phases. In scenarios with modest demand and petroleum production, employment may at some point of time even be lower than a scenario without increased petroleum activity. In the two scenarios with low and high levels of petroleum activity in the northeastern Norwegian Sea, total annual employment in Norway increases by respectively 3 000 and 10 000 persons at the most. On average for the period 2014-2045, the increase is 800 persons with a low level of activity and 2 300 persons with a high activity level. GDP excluding recovery will in the period 2014-2045, on average, increase by respectively 1.5 and 5.3 billion 2009 million annually in the two

  14. Juvenile Chinook Salmon abundance in the northern Bering Sea: Implications for future returns and fisheries in the Yukon River

    Science.gov (United States)

    Murphy, James M.; Howard, Kathrine G.; Gann, Jeanette C.; Cieciel, Kristin C.; Templin, William D.; Guthrie, Charles M.

    2017-01-01

    Juvenile Chinook Salmon (Oncorhynchus tshawytscha) abundance in the northern Bering Sea is used to provide insight into future returns and fisheries in the Yukon River. The status of Yukon River Chinook Salmon is of concern due to recent production declines and subsequent closures of commercial, sport, and personal use fisheries, and severe restrictions on subsistence fisheries in the Yukon River. Surface trawl catch data, mixed layer depth adjustments, and genetic stock mixtures are used to estimate juvenile abundance for the Canadian-origin stock group from the Yukon River. Abundance ranged from a low of 0.62 million in 2012 to a high of 2.58 million in 2013 with an overall average of 1.5 million from 2003 to 2015. Although abundance estimates indicate that average survival is relatively low (average of 5.2%), juvenile abundance was significantly correlated (r=0.87, p=0.005) with adult returns, indicating that much of the variability in survival occurs during early life-history stages (freshwater and initial marine). Juvenile abundance in the northern Bering Sea has increased since 2013 due to an increase in early life-history survival (average juveniles-per-spawner increased from 29 to 59). The increase in juvenile abundance is projected to produce larger runs and increased subsistence fishing opportunities for Chinook Salmon in the Yukon River as early as 2016.

  15. A step forward in understanding step-overs: the case of the Dead Sea Fault in northern Israel

    Science.gov (United States)

    Dembo, Neta; Granot, Roi; Hamiel, Yariv

    2017-04-01

    The rotational deformation field around step-overs between segments of strike-slip faults is poorly resolved. Vertical-axis paleomagnetic rotations can be used to characterize the deformation field, and together with mechanical modeling, can provide constraints on the characteristics of the adjacent fault segments. The northern Dead Sea Fault, a major segmented sinistral transform fault that straddles the boundary between the Arabian Plate and Sinai Subplate, offers an appropriate tectonic setting for our detailed mechanical and paleomagnetic investigation. We examine the paleomagnetic vertical-axis rotations of Neogene-Pleistocene basalt outcrops surrounding a right step-over between two prominent segments of the fault: the Jordan Gorge section and the Hula East Boundary Fault. Results from 20 new paleomagnetic sites reveal significant (>20˚) counterclockwise rotations within the step-over and small clockwise rotations in the vicinity. Sites located further (>2.5 km) away from the step-over generally experience negligible to minor rotations. Finally, we construct a mechanical model guided by the observed rotational field that allows us to characterize the structural, mechanical and kinematic behavior of the Dead Sea Fault in northern Israel.

  16. Interannual variation of rare earth element abundances in corals from northern coast of the South China Sea and its relation with sea-level change and human activities

    Science.gov (United States)

    Liu, Yajing; Peng, Z.; Wei, G.; Chen, T.; Sun, W.; He, J.; Liu, Gaisheng; Chou, C.-L.; Shen, C.-C.

    2011-01-01

    Here we present interannual rare earth element (REE) records spanning the last two decades of the 20th century in two living Porites corals, collected from Longwan Bay, close to the estuarine zones off Wanquan River of Hainan Island and Hong Kong off the Pearl River Delta of Guangdong Province in the northern South China Sea. The results show that both coral REE contents (0.5-40 ng g-1 in Longwan Bay and 2-250 ng g-1 in Hong Kong for La-Lu) are characterized with a declining trend, which are significantly negative correlated with regional sea-level rise (9.4 mm a-1 from 1981 to 1996 in Longwan Bay, 13.7 mm a-1 from 1991 to 2001 in Hong Kong). The REE features are proposed to be resulted from seawater intrusion into the estuaries in response to contemporary sea-level rise. However, the tendency for the coral Er/Nd time series at Hong Kong site is absent and there is no significant relation between Er/Nd and total REEs as found for the coral at Longwan Bay site. The observations are likely attributed to changes of the water discharge and sediment load of Pearl River, which have been significantly affected by intense human activities, such as the construction of dams/reservoirs and riverbed sediment mining, in past decades. The riverine sediment load/discharge ratio of the Pearl River decreased sharply with a rate of 0.02 kg m-3 a-1, which could make significant contribution to the declining trend of coral REE. We propose that coastal corals in Longwan Bay and similar unexplored sites with little influences of river discharge and anthropogenic disruption are ideal candidates to investigate the influence of sea-level change on seawater/coral REE. ?? 2010 Elsevier Ltd.

  17. Denudation History of South China Block and Sediment Supply to Northern Margin of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yan Yi; Hu Xiaoqiong; Lin Ge; Xia Bin; Li Xiaoyong; Remesh Chandra Patel

    2009-01-01

    On the basis of apatite fission track (AFT) analyses,this article aims to provide a quantitative overview of Cenozoic morphotectonic evolution and sediment supply to the northern margin of the South China Sea (SCS).Seventeen granite samples were collected from the coast to the inland of the South China block.Plots of AFT age against sample location with respect to the coastline show a general trend of youngling age away from the coast,which implies more prolonged erosion and sediment contribution at the inland of the South China Sea during post break-up evolution.Two-stage fast erosion process,Early Tertiary and Middle Miocene,is deduced from simulated cooling histories.The first fast cooling and denudation during Early Tertiary are recorded by the samples along the coast (between 70 and 60 Ma) and the inland (between 50 and 30 Mu),respectively.This suggests initial local erosion and deposition in the northern margin of the SCS during Early Tertiary.Fast erosion along the coast ceased since ca.50 Ma,while it had lasted until ca.30 Ma inland,indicating that the erosion was transferred from the local coastal zone initially toward the continental interior with unified subsidence of the northern margin,which resulted in the formation of a south-dipping topography of the continental margin.The thermal stosis in the South China block since ca.30 Mu must det'me the time at which the northern margin became dynamically disconnected from the active rifting and stretching that was taking place to the south.The lower erosion rate is inconsistent with higher sedimentary rate in the Pearl River Mouth basin during Late Oligocene (ca.25 Ma).This indicates that the increased sedimentation in the basin is not due to the erosion of the granite belt of the South China block,but perhaps points to the westward propagation of the paleo-Pearl River drainage related to the uplift of the eastern margin of Tibet plateau and southward jumping of spreading axis of the South China Sea

  18. Zooplankton communities fluctuations from 1995 to 2005 in the Bay of Villefranche-sur-Mer (Northern Ligurian Sea, France)

    Science.gov (United States)

    Vandromme, P.; Stemmann, L.; Berline, L.; Gasparini, S.; Mousseau, L.; Prejger, F.; Passafiume, O.; Guarini, J.-M.; Gorsky, G.

    2010-12-01

    An integrated analysis of the pelagic ecosystems of the Ligurian Sea is performed combining time series of different zooplankton groups (small and large copepods, chaetognaths, appendicularians, pteropods, thaliaceans, decapods larvae, other crustaceans, other gelatinous and other zooplankton), chlorophyll-a and nutrients, seawater salinity, temperature and density and local weather at the Point B coastal station (Northern Ligurian Sea). From January 1995 to December 2005, a shift in most variables occurred ca. 2000. From 1995 to 2000 winters were wet and mild resulting in lower winter sea surface density. These years showed lower than average nutrients and zooplankton concentrations while phytoplankton biomass was higher. After 2000, winters were colder and dryer resulting in higher sea surface density. Nutrients and zooplankton showed higher concentrations while phytoplankton was lower than average. The ca. 2000 shift was observed for most zooplankton groups with a one year delay for certain groups. The observed patterns suggest that the pelagic ecosystem trophic state is mostly set by the winter forcing on the convection that upwells nutrients to the surface sustaining the spring bloom. However, low phytoplankton concentrations in higher nitrate and zooplankton conditions during the well mixed years suggest that phytoplankton is controlled by grazers. The proposed mechanisms of convection regimes hold for most of the time series, but specific years with contradicting patterns needed to be explained by other factors. The limitation of phytoplankton growth by the light availability in spring/summer was then proposed as a secondary driving force that can moderate or even reverse the winter forcing. Finally, the eleven years of observation did not reveal a clear link with the North Atlantic Oscillation, suggesting a more complex dynamics linking large scale climate to Ligurian Sea ecosystems or that the length of the plankton monitoring is not yet sufficient to

  19. Zooplankton communities fluctuations from 1995 to 2005 in the Bay of Villefranche-sur-Mer (Northern Ligurian Sea, France

    Directory of Open Access Journals (Sweden)

    P. Vandromme

    2010-12-01

    Full Text Available An integrated analysis of the pelagic ecosystems of the Ligurian Sea is performed combining time series of different zooplankton groups (small and large copepods, chaetognaths, appendicularians, pteropods, thaliaceans, decapods larvae, other crustaceans, other gelatinous and other zooplankton, chlorophyll-a and nutrients, seawater salinity, temperature and density and local weather at the Point B coastal station (Northern Ligurian Sea. From January 1995 to December 2005, a shift in most variables occurred ca. 2000. From 1995 to 2000 winters were wet and mild resulting in lower winter sea surface density. These years showed lower than average nutrients and zooplankton concentrations while phytoplankton biomass was higher. After 2000, winters were colder and dryer resulting in higher sea surface density. Nutrients and zooplankton showed higher concentrations while phytoplankton was lower than average. The ca. 2000 shift was observed for most zooplankton groups with a one year delay for certain groups. The observed patterns suggest that the pelagic ecosystem trophic state is mostly set by the winter forcing on the convection that upwells nutrients to the surface sustaining the spring bloom. However, low phytoplankton concentrations in higher nitrate and zooplankton conditions during the well mixed years suggest that phytoplankton is controlled by grazers. The proposed mechanisms of convection regimes hold for most of the time series, but specific years with contradicting patterns needed to be explained by other factors. The limitation of phytoplankton growth by the light availability in spring/summer was then proposed as a secondary driving force that can moderate or even reverse the winter forcing. Finally, the eleven years of observation did not reveal a clear link with the North Atlantic Oscillation, suggesting a more complex dynamics linking large scale climate to Ligurian Sea ecosystems or that the length of the plankton monitoring is

  20. Tidal and sub-tidal sea level variability at the northern shelf of the Brazilian Northeast Region

    Directory of Open Access Journals (Sweden)

    FELIPE F. FROTA

    2016-01-01

    Full Text Available ABSTRACT A characterization of the sea level variability at tidal and sub-tidal frequencies at the northern shore of the Brazilian Northeast shelf for the period 2009-2011 is presented. The sea level data used was obtained from the Permanent Geodetic Tide Network from the Brazilian Institute of Geography and Statistics for the Fortaleza gauge station. Local wind data was also used to assess its effects on the low-frequency sea level variability. The variability of the sea level was investigated by classical harmonic analysis and by morphology assessment over the tidal signal. The low frequencies were obtained by low-pass filtering. The tidal range oscillated with the highest value of 3.3 m during the equinox and the lowest value of 0.7 m during the solstice. Differences between the spring and neap tides were as high as 1 m. A total of 59 tidal constituents were obtained from harmonic analysis, and the regional tide was classified as semi-diurnal pure with a form number of 0.11. An assessment of the monthly variability of the main tidal constituents (M2, S2, N2, O1, and K1 indicated that the main semi-diurnal solar S2 presented the highest variability, ranging from 0.21 to 0.41 m; it was the main element altering the form number through the years. The low frequency sea-level variability is negligible, although there is a persistent signal with an energy peak in the 10-15 day period, and it cannot be explained by the effects of local winds.