283 research outputs found

    Seamounts and oceanic igneous features in the NE Atlantic: a link between plate motions and mantle dynamics

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    A new regional compilation of seamount-like oceanic igneous features (SOIFs) in the NE Atlantic points to three distinct oceanic areas of abundant seamount clusters. Seamounts on oceanic crust dated 54–50 Ma are formed on smooth oceanic basement, which resulted from high spreading rates and magmatic productivity enhanced by higher than usual mantle plume activity. Late Eocene–Early Miocene SOIF clusters are located close to newly formed tectonic features on rough oceanic crust in the Irminger, Iceland and Norway basins, reflecting an unstable tectonic regime prone to local readjustments of mid-ocean ridge and fracture zone segments accompanied by extra igneous activity. A SOIF population observed on Mid-Miocene–Present rough oceanic basement in the Greenland and Lofoten basins, and on conjugate Kolbeinsey Ridge flanks, coincides with an increase in spreading rate and magmatic productivity. We suggest that both tectonic/kinematic and magmatic triggers produced Mid-Miocene–Present SOIFs, but the Early Miocene westwards ridge relocation may have played a role in delaying SOIF formation south of the Jan Mayen Fracture Zone. We conclude that Iceland plume episodic activity combined with regional changes in relative plate motion led to local mid-ocean ridge readjustments, which enhanced the likelihood of seamount formation

    Rauch- und Mehlschwalben: Mitbewohner unserer GebÀude

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    »Eine Schwalbe macht noch keinen Sommer«, aber sie bringt Leben in oder an das Haus. Leider kennen immer weniger Menschen die lustig schwatzenden Rauchschwalben in StĂ€llen. Auch die FĂŒtterung von jungen Mehlschwalben in ihren Nestern an den Außenseiten von GebĂ€uden lĂ€sst sich immer weniger beobachten. Schwalben brauchen unsere Hilfe. Die reich bebilderte BroschĂŒre gibt Einblick in das interessante Leben der Schwalben. Sie zeigt Möglichkeiten auf, mit welchen meist einfachen Maßnahmen Rauch- und Mehlschwalben unterstĂŒtzt werden können und wie sich das gemeinsame Wohnen von Mensch und Schwalben unter einem Dach erleichtern lĂ€sst. Redaktionsschluss: 13.09.201

    An overview of the Upper Paleozoic-Mesozoic stratigraphy of the NE Atlantic region

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    This study describes the distribution and stratigraphic range of the Upper Paleozoic–Mesozoic succession in the NE Atlantic region, and is correlated between conjugate-margins and along the axis of the NE Atlantic rift system. The stratigraphic framework has yielded important new constraints on the timing and nature of sedimentary basin development in the NE Atlantic, with implications for rifting and the breakup of the Pangaean supercontinent. From a regional perspective, the Permian–Triassic succession records a northward transition from an arid interior to a passively-subsiding, mixed carbonate/siliciclastic shelf margin. A Late Permian–earliest Triassic rift pulse has regional expression in the stratigraphic record. A fragmentary paralic to shallow-marine Lower Jurassic succession reflects Early Jurassic thermal subsidence and mild extensional tectonism; this was interrupted by widespread Mid-Jurassic uplift and erosion, and followed by an intense phase of Late Jurassic rifting in some (but not all) parts of the NE Atlantic region. The Cretaceous succession is dominated by thick basinal-marine deposits, which accumulated within and along a broad zone of extension and subsidence between Rockall and NE Greenland. There is no evidence for a substantive and continuous rift system along the proto-NE Atlantic until the Late Cretaceous

    The pre-breakup stratigraphy and petroleum system of the Southern Jan Mayen Ridge revealed by seafloor sampling

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    The authors would like to acknowledge the contribution from the vessel’s crew (captain I. Rasmussen) and operator (Thor Ltd), the two surveyors (K. Hþyséth and H.B. Bortne), and two sampling assistants (F. Gausepohl and A.-M. Voelsch). Sverre Planke and Dougal Jerram are partly funded through a Norwegian Research Council Centers of Excellence project (project number 223272, CEED). Adriano Mazzini is funded by the European Research Council under the European Union's Seventh Framework Programme Grant agreement n° 308126 (LUSI LAB project, PI A. Mazzini). TGS and VBPR funded the cruise and allowed the publication of the data and interpretation. Steve Killops from APT refined our interpretation of the biomarker data. The reviewers and the editor are also thanked for their constructive comments. Finally, this article is dedicated to the biostratigrapher Haavard Selnes who sadly passed away in 2015.Peer reviewedPostprin

    Warranty Data Analysis: A Review

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    Warranty claims and supplementary data contain useful information about product quality and reliability. Analysing such data can therefore be of benefit to manufacturers in identifying early warnings of abnormalities in their products, providing useful information about failure modes to aid design modification, estimating product reliability for deciding on warranty policy and forecasting future warranty claims needed for preparing fiscal plans. In the last two decades, considerable research has been conducted in warranty data analysis (WDA) from several different perspectives. This article attempts to summarise and review the research and developments in WDA with emphasis on models, methods and applications. It concludes with a brief discussion on current practices and possible future trends in WDA

    Sub-surface geology and velocity structure of the Krafla high temperature geothermal field, Iceland : Integrated ditch cuttings, wireline and zero offset vertical seismic profile analysis

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    The research leading to these results has received funding from the European Community's Seventh Framework Programme under grant agreement No. 608553 (Project IMAGE). The VMAPP project run by VBPR, DougalEARTH Ltd. and TGS also contributed funding to the borehole characterization of the K-18 borehole. Landsvirkun is acknowledged for their effort and assistance in this work and in particular for allowing the use of the data from well K-18. We further acknowledge the support from the Research Council of Norway through its Centres of Excellence funding scheme, project 22372 (SP and DAJ).Peer reviewedPostprin
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