We present ionospheric plasma conditions observed by the EISCAT radars in Tromsø and on Svalbard, covering 68°–81° geomagnetic latitude, during 6–8 September 2017. This is a period when X2.2 and X9.3 X‐ray flares occurred, two interplanetary coronal mass ejections (ICMEs) arrived at the Earth accompanied by enhancements of MeV‐range energetic particle flux in both the solar wind (SEP event) and inner ...

Sub-seafloor hydrothermal processes along volcanically active plate boundaries are integral to the formation of seafloor massive sulfide deposits and to oceanic iron cycling, yet the nature of their relationship is poorly understood. Here we apply iron isotope analysis to sulfide minerals from the Trans-Atlantic Geotraverse (TAG) mound and underlying stockwork, 26°N Mid-Atlantic Ridge, to trace ...

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 ...

Microbial communities in deep subsurface sediments are challenged by the decrease in amount and quality of organic substrates with depth. In sediments of the Baltic Sea, they might additionally have to cope with an increase in salinity from ions that have diffused downward from the overlying water during the last 9000 years. Here, we report the isolation and characterization of four novel bacteria ...

During the last glacial period large parts of the Arctic, including the Barents Sea, north of Norway and Russia, were covered by ice sheets. Despite several studies indicating that melting occurred beneath much of the Barents Sea ice sheet, very few meltwater-related landforms have been identified. We document ∼200 seafloor valleys in the central Barents Sea and interpret them to be tunnel valleys ...

Early to Middle Miocene sea-level oscillations of approximately 40–60 m estimated from far-field records1,2,3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene4,5. Data and model outputs can ...

Three depth-converted and geologically interpreted seismic profiles provide a clear image of the offshore outer accretionary wedge associated with oblique subduction of the Pacific Plate beneath the central Hikurangi margin. Plio-Quaternary turbidites deposited over the pelagic cover sequence of the Hikurangi Plateau have been accreted to the margin by imbrication along E-verging thrust faults that ...

We reconstruct climate and changes in water-mass properties in relation to variations in palaeoproductivity at the south-western Svalbard margin throughout the last 2000 years. Environmental conditions in subsurface (ca. 250–75 m) and near-surface to surface water (75–0 m) were studied on the basis of the distribution patterns and fluxes of planktic foraminiferal faunas. Stable isotopes in three ...

A compilation of seismic data has been used to characterize the Neogene – Quaternary sedimentary succession of the northwestern Barents Sea continental margin to better understand the paleoenvironmental evolution and the sedimentary processes involved. The Neogene strata are dominated by contourites related to the ocean circulation established from the opening of the Fram Strait connecting the ...

In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from the shallow shelf show that analogue fault systems are present in coastal and onshore areas of NW ...