9 research outputs found

    The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2)

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    The Southern Ocean surrounding Antarctica is a region that is key to a range of climatic and oceanographic processes with worldwide effects, and is characterised by high biological productivity and biodiversity. Since 2013, the International Bathymetric Chart of the Southern Ocean (IBCSO) has represented the most comprehensive compilation of bathymetry for the Southern Ocean south of 60°S. Recently, the IBCSO Project has combined its efforts with the Nippon Foundation – GEBCO Seabed 2030 Project supporting the goal of mapping the world’s oceans by 2030. New datasets initiated a second version of IBCSO (IBCSO v2). This version extends to 50°S (covering approximately 2.4 times the area of seafloor of the previous version) including the gateways of the Antarctic Circumpolar Current and the Antarctic circumpolar frontal systems. Due to increased (multibeam) data coverage, IBCSO v2 significantly improves the overall representation of the Southern Ocean seafloor and resolves many submarine landforms in more detail. This makes IBCSO v2 the most authoritative seafloor map of the area south of 50°S

    The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2)

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    The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2) is a digital bathymetric model (DBM) for the area south of 50° S with special emphasis on the bathymetry of the Southern Ocean. IBCSO v2 has a resolution of 500 m × 500 m in a Polar Stereographic projection (EPSG: 9354). The total data coverage of the seafloor is 23.79% with a multibeam-only data coverage of 22.32%. The remaining 1.47% include singlebeam and other data. IBCSO v2 is the most authoritative seafloor map of the area south of 50°S. IBCSO is a regional mapping project of the General Bathymetric Chart of the Ocean (GEBCO) supported by the Nippon Foundation – GEBCO Seabed 2030 Project. GEBCO is a project under the auspices of the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission (IOC) with the goal to produce the authoritative map of the world's oceans. The IBCSO Project is also an integral part of the Antarctic research community and an expert group of the Scientific Committee on Antarctic Research (SCAR). For further information about the IBCSO Project, please visit http://www.ibcso.org

    The Porcupine Bank Canyon coral mounds: oceanographic and topographic steering of deep-water carbonate mound development and associated phosphatic deposition

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    The head of a canyon system extending along the western Porcupine Bank (west of Ireland) and which accommodates a large field of giant carbonate mounds was investigated during two cruises (INSS 2000 and TTR-13). Multibeam and sidescan sonar data (600–1,150 m water depth) suggest that the pre-existing seabed topography acts as a significant factor controlling mound distribution and shape. The mounds are concentrated along the edges of the canyon or are associated with a complex fault system traced around the canyon head, comprising escarpments up to 60 m high and several km long. The sampling for geochemical and petrographic analysis of numerous types of authigenic deposits was guided by sidescan sonar and video recordings. Calcite-cemented biogenic rubble was observed at the top and on the flanks of the carbonate mounds, being associated with both living and dead corals (Lophelia pertusa, Madrepora oculata and occasional Desmophyllum cristagalli). This can plausibly be explained by dissolution of coral debris facilitated by strong currents along the mound tops and flanks. In turn, the dissolved carbon is recycled and precipitated as interstitial micrite. Calcite, dolomite and phosphatic hardgrounds were identified in samples from the escarpment framing the eastern part of the survey area. The laterally extensive phosphatic hardgrounds represent a novel discovery in the region, supplying hard substrata for the establishment of new coral colonies. Based on existing knowledge of regional oceanographic conditions, complemented with new CTD measurements, it is suggested that water column stratification, enhanced bottom currents, and upwelling facilitate the deposition of organic matter, followed by phosphatisation leading to the formation of phosphate-glauconite deposits. The occurrence of strong bottom currents was confirmed by means of video observations combined with acoustic and sampling data, providing circumstantial evidence of fine- to medium-grained sand. Evidently, slope breaks such as escarpments and deep-water canyon headwalls are important structural elements in the development of mature carbonate mounds induced by deep-water coral growth. Stable isotope data show no evidence of methane-derived carbon in the carbonates and lithified sediments of the Porcupine Bank Canyon mounds

    A HUPO test sample study reveals common problems in mass spectrometry-based proteomics

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    We performed a test sample study to try to identify errors leading to irreproducibility, including incompleteness of peptide sampling, in liquid chromatography-mass spectrometry-based proteomics. We distributed an equimolar test sample, comprising 20 highly purified recombinant human proteins, to 27 laboratories. Each protein contained one or more unique tryptic peptides of 1,250 Da to test for ion selection and sampling in the mass spectrometer. Of the 27 labs, members of only 7 labs initially reported all 20 proteins correctly, and members of only 1 lab reported all tryptic peptides of 1,250 Da. Centralized analysis of the raw data, however, revealed that all 20 proteins and most of the 1,250 Da peptides had been detected in all 27 labs. Our centralized analysis determined missed identifications (false negatives), environmental contamination, database matching and curation of protein identifications as sources of problems. Improved search engines and databases are needed for mass spectrometry-based proteomics.8 page(s
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