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

Journal of Ocean University of China 2013年第3期12卷 345-354页

作者： BIAN Changwei JIANG Wensheng Richard J.Greatbatch DING Hui Physical Oceanography Laboratory Ocean University of China Helmholtz Centre for Ocean Research at Kiel University (geomar)

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

关键词： ROMS model turbidity observation seasonal variation bottom stress vertical mixing

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Heat tolerance may determine activity time in coprophagic beetle species (Coleoptera:Scarabaeidae)

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Insect Science 2021年第4期28卷 1076-1086页

作者： Nonofo Gotcha Honest Machekano Ross N.Cuthbert Casper Nyamukondiwa Department of Biological Sciences and Biotechnology Botswana International University of Science and TechnologyPalapyeBotswana geomar Helmholtz-Zentrum fur Ozeanforschung KielKielGermany

Although reports have documented loss of species diversity and ecological services caused by stressful temperature changes that result from climate change,some species cope through behavioral *** temperatures and magnitudes of temperature extremes increase,animals should compensate to maintain fitness(such as through temporary behavioral shifts in activity times).Appropriate timing of activity helps avoid competition across *** coprophagic dung beetles exhibit species-specific temporal activity times,it is unknown whether temperature drives evolution of these species-specific temporal activity *** nine dung beetle species(three each of diurnal,crepuscular,and nocturnal species),we explored differences in heat stress tolerance measured as critical thermal maxima(CTmax;the highest temperature allowing activity)and heat knockdown time(HKDT;survival time under acute heat stress)across these species,and examined the results using a phylogenetically informed *** results showed that day-active species had significantly higher CTmax(diurnal>crepuscular=nocturnal species),whereas crepuscular species had higher HKDT(crepuscular>nocturnal>diurnal species).There was no correlation between heat tolerance and body size across species with distinct temporal activity,and no significant phylogenetic constraint for *** with higher CTmax did not necessarily have higher HKDT,which indicates that species may respond differently to diverse heat tolerance *** heat tolerance for diurnal beetles indicates that this trait may constrain activity time and,under high acute temperatures with climate change,species may shift activity times in more benign *** results contribute to elucidate the evolution of foraging behavior and management of coprophagic beetle ecosystem services under changing environments.

关键词： biodiversity climate change dung beetle ecosystem services thermal tolerance

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Indicators of δ^(13)C and δ^(18)O of gas hydrate-associated sediments

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Chinese Science Bulletin 2002年第19期47卷 1659-1663页

作者： E. Suess Faculty of Earth Sciences China University of Geosciences Wuhan China Department of Marine Environmental Geology GEOMAR University of Kiel Kiel Germany

The analyses of δ13C and δ18O of gas hydrate-associated sediments from two cores on Hydrate Ridge in Cascadia convergent margin offshore Oregon, eastern North Pacific show the values of δ13C from-29.81‰ to -48.28‰(PDB) and δ18O from 2.56‰to 4.28‰ (PDB), which could be plotted into a group called typical carbonate minerals influenced by the methane in cold venting. Moreover, the values of δ13C and δ18O show a consistent trend in both cores from top to bottom with increasing of δ13C and decreasing of δ18O. This trend could be explained as an effect caused by the anaerobic oxidation of methane (AOM) in depth and the oxygen fraction during the formation of gas hydrate in depth together. These characteristics of δ13C and δ18O indicate that the gas hydrate-associated sediments are significantly different from the normal marine carbonates, and they are deeply influenced by the formation and evolution of gas hydrate. So, the distinct characteristics of δ13C and δ18O of gas hydrate-associated

关键词： gas hydrate associated sediments δ13C and δ18O indi-cators.

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Early Development of Silvetia babingtonii(Fucales, Phaeophyceae)

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Journal of Ocean University of China 2014年第4期13卷 677-682页

作者： WANG Gaoge WEI Xiaojiao SHUAI Limei LU Bojun WANG Shasha KANG Dongdong College of Marine Life Sciences Ocean University of China Helmholtz-Zentrum für Ozeanforschung Kiel (geomar) Düsternbrooker Weg 20 24105 KielGermany

Silvetia babingtonii is a potentially economic brown alga for sources of food and high-value added utilization. So far, sporeling nursery and field cultivation has not been successful. The lack of knowledge on development and life cycle of this alga hinder the development of techniques for the sporeings and cultivation. In this study, internal structure of oogonium and antherium of S. babingtonii was observed with hematoxylin and eosin staining and through microscope. Meanwhile, early development from zygotes to juvenile sporelings was studied at 20℃ under 60–100 μmol photons m-2 s-1. Zygotes germinated and divided into thallus and rhizoid cells. The larger thallus cells further divided and developed into juvenile sporelings; while the smaller rhizoid cells divided and elongated into rhizoid hairs. These findings documented the life cycle of S. babingtonii and provided fundamental knowledge for sporeling nursery in the near future.

关键词： Silvetia babingtonii conceptacles early development life cycle receptacles

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The Character and Formation of Elongated Depressions on the Upper Bulgarian Slope

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Journal of Ocean University of China 2018年第3期17卷 555-562页

作者： XU Cuiling GREINERT Jens HAECKEL Matthias BIALAS Jorg DIMITROV Lyubomir ZHAO Guangtao College of Marine Geo-Sciences Ocean University of China Qingdao 266100 China geomar Helmholtz Centre for Ocean Research Kiel Kiel 24148 Germany Institute of Oceanology Bulgarian Academy of Science Varna 9000 Bulgaria

Seafloor elongated depressions are indicators of gas seepage or slope instability. Here we report a sequence of slopeparallel elongated depressions that link to headwalls of sediment slides on upper slope. The depressions of about 250 m in width and several kilometers in length are areas of focused gas discharge indicated by bubble-release into the water column and methane enriched pore waters. Sparker seismic profiles running perpendicular and parallel to the coast, show gas migration pathways and trapped gas underneath these depressions with bright spots and seismic blanking. The data indicate that upward gas migration is the initial reason for fracturing sedimentary layers. In the top sediment where two young stages of landslides can be detected, the slopeparallel sediment weakening lengthens and deepens the surficial fractures, creating the elongated depressions in the seafloor supported by sediment erosion due to slope-parallel water currents.

关键词： methane seepage elongated depression pockmark landslide Black Sea

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Upper Mantle Density Heterogeneity in the European-Anatolian Tethys Belt

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Acta Geologica Sinica(English Edition) 2021年第S01期95卷 9-10页

作者： Alexey SHULGIN Irina M.ARTEMIEVA CEED University of OsloNorway School of Earth Sciences China University of GeosciencesWuhanChina Marine Geodynamics GEOMAR Helmholtz Center for Ocean ResearchKielGermany Department of Geophysics Stanford UniversityCAUSA

We present a new model for the density structure of the lithosphere mantle(LM)in the region that extends from the Atlantic coast of Eurasia to the Ural mountains and from northern Africa and Arabia to the Arctic shelf... 详细信息

关键词： Upper mountains mantle

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A Global Perspective on Crustal Structure and Evolution based on A New Crustal Classification

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Acta Geologica Sinica(English Edition) 2021年第S01期95卷 48-50页

作者： Irina M.ARTEMIEVA Alexey SHULGIN School of Earth Sciences China University of GeosciencesWuhan 430074China Marine Geodynamics GEOMAR Helmholtz Center for Ocean ResearchKielGermany Department of Geophysics Stanford UniversityCAUSA CEED University of OsloNorway

Knowledge of the crustal structure is the key for understanding physical and chemical conditions of its formation and later modification by geodynamic *** has long been recognized that crustal structure is controlled by tectonic settings,and that the crustal thickness is one of the most important parameters that reflects the geodynamic origin of the crust.A long tectonic life of continental crust leads to its significant reworking by plate tectonics processes and crust-mantle interaction,which include mechanical extension.

关键词： crustal delamination granitization basin subsidence orogenic processes continental rifting hotspots continental shelves failed oceans oceanic crust

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Shifting chemical defence or novel weapons? A review of defence traits in Agarophyton vermiculophyllum and other invasive seaweeds

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Marine Life Science & Technology 2022年第1期4卷 138-149页

作者： Gaoge Wang Yifei Ren Shasha Wang Minglei Hou Florian Weinberger Institute of Evolution and Marine Biodiversity College of Marine Life SciencesOcean University of ChinaQingdao266003China Marine Ecology Division GEOMAR Helmholtz-Zentrum für Ozeanforschung KielDüsternbrooker Weg 2024105KielGermany

Seaweed bioinvasions increasingly affect coastal environments around the world, which increases the need for predictive models and mitigation strategies. The biotic interactions between seaweed invaders and invaded communities are often considered a key determinant of invasion success and failure and we here revise the current evidence that the capacity of seaweed invaders to deter enemies in newly reached environments correlates with their invasion success. Particularly efficient chemical defences have been described for several of the more problematic seaweed invaders during the last decades. However, confirmed cases in which seaweed invaders confronted un-adapted enemies in newly gained environments with deterrents that were absent from these environments prior to the invasion (so-called “novel weapons”) are scarce, although an increasing number of invasive and non-invasive seaweeds are screened for defence compounds. More evidence exists that seaweeds may adapt defence intensities to changing pressure by biological enemies in newly invaded habitats. However, most of this evidence of shifting defence was gathered with only one particular model seaweed, the Asia-endemic red alga Agarophyton vermiculophyllum, which is particularly accessible for direct comparisons of native and non-native populations in common garden experiments. A. vermiculophyllum interacts with consumers, epibionts and bacterial pathogens and in most of these interactions, non-native populations have rather gained than lost defensive capacity relative to native conspecifics. The increases in the few examined cases were due to an increased production of broad-spectrum deterrents and the relative scarcity of specialized deterrents perhaps reflects the circumstance that seaweed consumers and epibionts are overwhelmingly generalists.

关键词： Agarophyton vermiculophyllum Bioinvasion Chemical defence Novel weapons hypothesis Shifting defence hypothesis

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Observed Suspended Sediment Dynamics during a Tidal Cycle above Submerged Asymmetric Compound Sand Waves

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Journal of Environmental Science and Engineering(A) 2016年第7期5卷 333-355页

作者： Ingo Hennings Dagmar Herbers Department of Ocean Circulation and Climate Dynamics GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel 24148 Germany

The data from Acoustic Doppler Current Profiler （ADCP） of the three-dimensional current-field, echo intensity, modulation of Suspended Sediment Concentration （SSC）, and related water levels and wind velocities have been analyzed as a function of water depth above submerged asymmetric compound sand waves during a tidal cycle in the Lister Tiefofthe German Bight in the North Sea. Signatures of vertical current component, echo intensities and calculated SSC modulations in the water column depend strongly on wind and current velocity. Bursts of vertical current component and echo intensity are triggered by sand waves itself as well as by superimposed megaripples due to current wave interaction at high current ≥ 1.0 m＇s1 and wind speeds ≥ 10.0 m·s^-1, preferably of opposite directions, measured at high spatial resolution. The magnitude of currents and SSC modulations during ebb and flood tidal current phases are only weakly time dependent, whereas the local magnitudes of these parameters are variable in space above the sand waves. Some hydrodynamic parameters are further investigated and analyzed, showing a consistence of ADCP measurements in the applied theory.

关键词： Acoustic Doppler Current Profiler suspended sediment concentration asymmetric compound sand wave dynamic buoyancy density action density.

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1/3 of Antarctica is Not a Continent: Geophysical Evidence for West Antarctica as a Backarc System

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Acta Geologica Sinica(English Edition) 2021年第S01期95卷 51-54页

作者： Irina M.ARTEMIEVA Hans THYBO School of Earth Sciences China University of GeosciencesWuhan 430074China Section of Marine Geodynamics GEOMAR Helmholtz Center for Ocean ResearchKielGermany Department of Geophysics Stanford UniversityCAUSA Eurasia Institute of Earth Sciences Istanbul Technical UniversityTurkey

Antarctica has traditionally been considered continental inside the coastline of ice and *** our recent study(Artemieva and Thybo,2020)we reconsider the conventional extent of this continent and demonstrate that 1/3 o... 详细信息

关键词： paleosubduction back-arc extension continental crust lithosphere upper mantle

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