Blar i utgivelsesdato Artikler, rapporter og annet (geovitenskap)
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First record of catacrinid crinoid from the Lower Permian of Spitsbergen
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)An early Permian (late Artinskian–Roadian) cladid crinoid (Catacrinidae gen. et sp. indet.) is reported for the first time from the Vøringen Member of the Kapp Starostin Formation of Spitsbergen. The specimen is partly articulated and preserves a considerable part of its stalk and a complete cup, but only the proximal portions of its arms. Thus, it can− not be identified with any degree of ... -
Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Three marine sediment cores distributed along the Norwegian (MD95-2011), Barents Sea (JM09-KA11-GC), and Svalbard (HH11-134-BC) continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW) and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set ... -
Subglacial roughness of the former Barents Sea ice sheet
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)The roughness of a glacier bed has high importance for the estimation of the sliding velocity and can also provide valuable insights into the dynamics and history of ice sheets, depending on scale. Measurement of basal properties in present-day ice sheets is restricted to ground-penetrating radar and seismics, with surveys retrieving relatively coarse data sets. Deglaciated areas, like the Barents ... -
K-Ar illite and apatite fission track constraints onbrittle faulting and the evolution of the northern Norwegian passive margin
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Determining the timing of post-Caledonian brittle faulting in northern Norway is important for the understanding of the extensional tectonic evolution of the north Norwegian continental margin. Fault gouges from the Troms and Vesterålen regions of northern Norway yield Carboniferous to Permian and Carboniferous to Cretaceous K–Ar illite ages, respectively. The results show a contrast in fault activity ... -
Sub sea surface temperatures in the Polar North Atlantic during the Holocene: Planktic foraminiferal Mg/Ca temperature reconstructions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Holocene sea surface temperatures in the eastern Fram Strait are reconstructed based on Mg/Ca ratios measured on the planktic foraminifer Neogloboquadrina pachyderma (sin). The reconstructed sub sea surface temperatures (sSSTMg/Ca) fluctuate markedly during the earliest Holocene at ~11.7 and 10.5 kyr BP. This is probably in response to the varying presence of sea-ice and deglacial meltwater. Between ... -
Offshore permafrost decay and massive seabed methane escape in water depths >20 m at the South Kara Sea shelf
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-07-14)Since the Last Glacial Maximum (~19 ka), coastal inundation from sea-level rise has been thawing thick subsea permafrost across the Arctic. Although subsea permafrost has been mapped on several Arctic continental shelves, permafrost distribution in the South Kara Sea and the extent to which it is acting as an impermeable seal to seabed methane escape remains poorly understood. Here we use >1300 km ... -
Formation of a large submarine crack during the final stage of retrogressive mass wasting on the continental slope offshore northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-08-30)High-resolution swath-bathymetry data integrated with sub-bottom profiles and single-channel seismics reveal an 18 km long, up to 1000 m wide and 10-15 m deep crack located approx. 4 km upslope from a slide scar on the continental slope off northern Norway. This crack is formed by subsidence of the sea-floor sediments to a depth of 120 m due to downslope movement of a ~80 km2 large sediment slab ... -
Arctic Ocean glacial history
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-11-14)While there are numerous hypotheses concerning glacial–interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the ... -
Pink marine sediments reveal rapid ice melt and Arctic meltwater discharge during Dansgaard-Oeschger warmings
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-11-22)The climate of the last glaciation was interrupted by numerous abrupt temperature fluctuations, referred to as Greenland interstadials and stadials. During warm interstadials the meridional overturning circulation was active transferring heat to the north, whereas during cold stadials the Nordic Seas were ice-covered and the overturning circulation was disrupted. Meltwater discharge, from ice sheets ... -
Aligned glaciotectonic rafts on the central Barents Sea seafloor revealing extensive glacitectonic erosion during the last deglaciation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-12-07)Erosion rates on glaciated continental shelves are remarkably high, especially within ice stream troughs. Although glaciotectonic erosion may have considerably contributed to enhanced glacial erosion of these landscapes, entrainment mechanisms of glaciotectonically emplaced megablocks and rafts remain little understood. Here we report a northeast-southwest trending chain of over 1300 glacial rafts, ... -
On Palaeozoic-Mesozoic brittle normal faults along the SW Barents Sea margin: fault processes and implications for basement permeability and margin evolution
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Water mass exchange between the Nordic Seas and the Arctic Ocean on millennial time scale during MIS 4–2
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)The climate of the last glaciation circa 65,000–25,000 years ago was interrupted by about 15 abrupt temperature fluctuations, the so-called Dansgaard-Oeschger events consisting of warm interstadials and cold stadials recorded in Greenland ice cores. The largest fluctuations occur in the North Atlantic region, but they have been registered over the most of the world. The events are linked to changes ... -
A North Atlantic tephrostratigraphical framework for 130–60 ka b2k: new tephra discoveries, marine-based correlations, and future challenges
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
A Late Glacial–Early Holocene multiproxy record from the eastern Fram Strait, Polar North Atlantic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Optimising the use of marine tephrochronology in the North Atlantic: a detailed investigation of the Faroe Marine Ash Zones II, III and IV
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Temporal and spatial structure of multi-millennial temperature changes at high latitudes during the Last Interglacial
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Linking onshore-offshore basement rock architecture and brittle faults on the submerged strandflat along the SW Barents Sea margin, using high-resolution (5 x 5 m) bathymetry data
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Re-evaluation and extension of the Marine Isotope Stage 5 tephrostratigraphy of the Faroe Islands region: The cryptotephra record
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Semibrittle deformation and partial melting of perthitic K-feldspar: An experimental study
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Carbon isotope (d13C) excursions suggest times of major methane release during the last 14 ka in Fram Strait, the deep-water gateway to the Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)