The oldest part of the upper Riphean (Cryogenian) sedimentary succession of the Varanger Peninsula, North Norway, includes a series of sandstone-dominated units of fluvio-deltaic to shallow-marine origin and thinner, intercalated mudstone-rich units. The sedimentology and stratigraphic understanding of the mudstone-rich units are less complete compared to their sandstone-dominated counterparts. In ...

Paleokarst breccias are a common feature of sedimentary rift basins. The Billefjorden Trough in the High Arctic archipelago of Svalbard is an example of such a rift. Here the Carboniferous stratigraphy exhibits intervals of paleokarst breccias formed by gypsum dissolution. In this study we integrate digital outcrop models (DOMs) with a 2D ground penetrating radar (GPR) survey to extrapolate external ...

Whilst there has been a recent appreciation for the role of open-system pingos in providing a fluid-flow conduit through continuous permafrost that enables methane release, the formation and internal structure of these ubiquitous permafrost-diagnostic landforms remains unclear. Here, we combine active-source seismic measurements with electrical resistivity tomography (ERT) to investigate the structural ...

Geophysical surveying of the Arctic will become increasingly important in future prospecting and monitoring of the terrestrial and adjacent areas in this hemisphere. Seismic data acquired on floating ice are hampered with extensive noise due to ice vibrations related to highly dispersive ice flexural waves generated by the seismic source. Several experiments have been conducted on floating ice in ...

Semi-quantitative estimates of early to late Holocene spring sea ice concentration (SpSIC) andoccurrence of summer sea ice for the northern Barents Sea have been obtained by analysing the biomarkers IP₂₅,brassicasterol and a tri-unsaturated highly branched isoprenoid lipid in a Holocene marine sediment core.Sub-surface water mass variations were derived from planktic foraminiferal assemblages ...

Glacial groundwater can mobilize deep-seated methane from beneath glaciers and permafrost in the Arctic, leading to atmospheric emissions of this greenhouse gas. We present a temporal, hydro-chemical dataset of methane-rich groundwater collected during two melt seasons from a high Arctic glacial forefield to explore the seasonal dynamics of methane emissions. We use methane and ion concentrations ...

The evolution of submarine pockmarks is often related to the ascent of fluid from the subsurface. For pockmarks located within the gas hydrate stability zone, methane oversaturation can result in the formation of gas hydrates in the sediment. An ~600 m‐wide sea floor depression in deep waters offshore Nigeria, Pockmark A, was investigated for distributions and quantities of shallow gas hydrates, ...

The Palaeocene–Eocene Thermal Maximum (PETM) was a global warming event of 5–6 °C around 56 million years ago caused by input of carbon into the ocean and atmosphere. Hydrothermal venting of greenhouse gases produced in contact aureoles surrounding magmatic intrusions in the North Atlantic Igneous Province have been proposed to play a key role in the PETM carbon-cycle perturbation, but the precise ...

Planktonic calcifiers, the foraminiferal species <i>Neogloboquadrina pachyderma</i> and <i>Turborotalita quinqueloba</i>, and the thecosome pteropod <i>Limacina helicina</i> from plankton tows and surface sediments from the northern Barents Sea were studied to assess how shell density varies with depth habitat and ontogenetic processes. The shells were measured using X-ray microcomputed tomography ...

The Barents Sea Ice Sheet was part of an interconnected complex of ice sheets, collectively referred to as the Eurasian Ice Sheet, which covered north-westernmost Europe, Russia and the Barents Sea during the Last Glacial Maximum (around 21 ky BP). Due to common geological features, the Barents Sea component of this ice complex is seen as a paleo-analogue for the present-day West Antarctic Ice Sheet. ...