CAGE17-2 Cruise Report: Gas hydrate deposits and methane seepages in Storfjordrenna, Northern Flank of Olga Basin, and West Sentralbanken (Barents Sea): Biogeochemical and biological investigations

Panieri, Giuliana; Alexandropoulou, Nikolitsa; Bruvik, Kine L.; Carrier, Vincent; Dessandier, David; Dølven, Knut Ola; Valberg, Espen; Fornari, Daniel J.; Gründger, Friederike; Kurras, G.; Yao, Haoyi; Holm, Truls; Lindgren, Matteus; Melaniuk, Katarzyna; Olsen, Bjørn R.; Ofstad, Siri; Patton, Henry; Romeyn, Rowan; Sauer, Simone; Sen, Arunima; Sert, Muhammed Fatih

doi:10.7557/cage.6955

Cited by 2 publications

(2 citation statements)

References 3 publications

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“…Sars, and bathymetric maps with horizontal resolution of 5 m were acquired by the MAREANO programme (www.mareano.no) and provided by the Norwegian Hydrographic Service. Multibeam echosounder data over Hopendjupet were collected during Centre for Arctic Gas Hydrates, Environment and Climate (CAGE) cruises CAGE_17-2 (Panieri et al, 2023), CAGE_ 20-2 (Patton et al, 2022a), CAGE_21-4 (Winsborrow et al, 2022, CAGE_21-6 Knies, 2022), andCAGE 22-6 (Serov et al, 2022) on-board R/V Helmer Hanssen and R/V G.O. Sars.…”

Section: Methods and Datamentioning

confidence: 99%

Distinct modes of meltwater drainage and landform development beneath the last Barents Sea ice sheet

et al. 2023

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The flow of glacial ice is impacted by basal meltwater drainage systems that fluctuate on a continuum from distributed, high-pressure environments to channelized, lower pressure networks. Understanding the long-term development of dominant drainage modes and impacts on ice flow and landform development is a crucial step in predicting palaeo and contemporary ice-mass response to changes in climate. The spatial and temporal scales at which different drainage modes operate are largely unknown, and the geomorphological legacy of subglacial meltwater networks that evolve over a glaciation provide composite records of drainage system development. Here, we use high-resolution bathymetric data from shallow banks in the central Barents Sea to map the geomorphological imprint of meltwater drainage beneath the collapsing marine-based Barents Sea Ice Sheet (BSIS). We observe a succession of distinct meltwater landforms that provide relative timing constraints for subglacial drainage modes, indicating that extensive networks of channelized drainage were in operation during deglaciation. Interlinked basins and channels suggest that meltwater availability and drainage system development was influenced by filling and draining cycles in subglacial lakes. Networks of eskers also indicate near-margin meltwater conduits incised into basal ice during late-stage deglaciation, and we suggest that these systems were supplemented by increased inputs from supraglacial melting. The abundance of meltwater during the late stages of BSIS deglaciation likely contributed to elevated erosion of the sedimentary substrate and the mobilisation of subglacial sediments, providing a sediment source for the relatively abundant eskers found deposited across bank areas. A newly discovered beaded esker system over 67 km long in Hopendjupet constrains a fluctuating, but generally decelerating, pace of ice retreat from ∼1,600 m ca-1 to ∼620 m ca−1 over central Barents Sea bank areas during a 91-year timespan.

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Section: Methods and Datamentioning

confidence: 99%

Distinct modes of meltwater drainage and landform development beneath the last Barents Sea ice sheet

et al. 2023

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“…1), in an area where water depths vary between 100 and 400 m. The region is a frontier exploration area with limited geological and geophysical data available, but where gas seepages, flares, pockmarks, submarine pingos and blow-out craters have been observed indicating the presence of an active petroleum system in the subsurface (e.g. Ehrhardt et al, 2016;Panieri et al, 2017;Plaza-Faverola et al, 2018;Andreassen et al, 2019;Amdal, 2019;Serov et al, 2023). Gas hydrates are locally associated with methane seepages (Andreassen et al, 1990;Løvø et al, 1990;Laberg and Andreassen, 1996;Westbrook et al, 2009;Åström et al, 2016;Andreassen et al, 2017;Waage et al, 2019), and oil slicks in the water column have also been observed (e.g.…”

Section: Introductionmentioning

confidence: 99%

Influence of Pleistocene Glaciation on Petroleum Systems and Gas Hydrate Stability in the Olga Basin Region, Barents Sea

Amberg,

Littke,

Lutz

et al. 2024

Journal of Petroleum Geology

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This study presents the results of a 2D numerical basin and petroleum systems model of the Olga Basin in the NW Barents Sea offshore northern Norway, a frontier exploration area in which there are abundant seafloor oil and gas seepages. The effects of Pleistocene ice sheet advances on rock properties and subsurface fluid migration in this area, and on seafloor hydrocarbon seepage, are not well understood. The 2D numerical model takes account of recurrent ice advances and retreats, together with related erosional and temperature effects, and investigates the influence of these parameters on fluid migration. Model results show that Pleistocene glaciations reduced the temperature in the sedimentary succession in the Olga Basin by up to 20 °C, for example in the uppermost Cretaceous and Jurassic sediments which underlie the seafloor down to a depth of 0.5 to 1 km. The decrease in temperature was in general predominantly related to the intensity of glacial erosion, which was set in this study to a depth of 600 m based on previous studies. Hydrocarbon fluids expelled from potential thermogenic source rocks of Carboniferous to Triassic ages on the SW margin of the Olga Basin migrated to the seafloor through permeable carrier beds. However, fluid migration to the surface in the NE of the study area took place along fault conduits. In a closed fault model scenario, only 0.3 Mt of hydrocarbons are modelled to have migrated along the 0.5 km wide model section; in a second scenario with partially open faults, about 22 Mt of hydrocarbons, representing about 11% of the total hydrocarbons generated by potential thermogenic source rocks in the study area, were lost to the surface during the Pleistocene. The potential for microbial methane generation in the Olga Basin was limited both during the Pleistocene and at the present day due to the significant reduction in temperature during glacial episodes, and due to the intense glacial‐related erosion of the Mesozoic to Cenozoic stratigraphy. During glacial stages, the gas hydrate stability zone beneath the ice sheet is modelled to have extended to a depth of up to 900 m for a pure methane composition, and to a depth of up to 1100 m for a possible thermogenic‐sourced mixed gas composition of 90% methane, 7% propane and 3% ethane. Gas hydrates with this mixed composition are modelled to have been stable in the Olga Basin during the last three glacial advances and into the present. These modelling results provide an insight into the key factors controlling the migration and surface leakage of hydrocarbon fluids in the Olga Basin region, and into the effects of glaciations on rock properties in a glaciated basin.

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CAGE17-2 Cruise Report: Gas hydrate deposits and methane seepages in Storfjordrenna, Northern Flank of Olga Basin, and West Sentralbanken (Barents Sea): Biogeochemical and biological investigations

Cited by 2 publications

References 3 publications

Distinct modes of meltwater drainage and landform development beneath the last Barents Sea ice sheet

Distinct modes of meltwater drainage and landform development beneath the last Barents Sea ice sheet

Influence of Pleistocene Glaciation on Petroleum Systems and Gas Hydrate Stability in the Olga Basin Region, Barents Sea

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