Norwegian Sea Basins Research Articles

Feeding ecology of Benthosema glaciale across the North Atlantic

The glacier lanternfish Benthosema glaciale is a key myctophid with a wide distribution in the northern Atlantic. It is a species that has a strong vertical migration capacity and have the potential to move between the surface waters and mesopelagic depths in a diel cycle (DVM), mainly depending on ambient light conditions. We investigated the feeding ecology of B. glaciale across the Norwegian, Iceland, Irminger and Labrador Sea basins. An important component of Benthosema diet was various types of calanoid copepods, but with some additional variability across the deep basins. ‘House’s’ of Appendicularia were only found in stomachs from the Labrador basin and were positively selected for here. The large calanoid Calanus hyperboreus was strongly selected for in the Iceland Sea, while its smaller counterpart C. finmarchicus was negatively selected for here. Fish from the Irminger, Labrador and Norwegian Seas displayed a high number of empty stomachs while no fish stomachs were found empty in the Iceland Sea. Contrary to expectation due to being located at the highest latitude, Benthosema in the Iceland Sea had significantly higher condition factor (for both small and large fish) and liver indices compared to fish from other basins, but the abundance of small fish in the sampled population here was very low. This contrasts with the “light environment exclusion” (LEE) hypothesis, which propose that the extreme light environment at higher latitudes restricts feeding opportunities for mesopelagic fish at high latitudes. It is suggested that improved classification of prey through stomach analyses should aim to allow bioluminescent organisms to be separated from non-bioluminescent prey if feasible. This would allow improved resolution to analyse stomach contents and certainly progress our understanding of the success of myctophids across variable habitats.

New Paleocene species and biostratigraphic relevance of the genus Spiniferites across the North Sea and Norwegian Sea

Industrial palynological studies of the Paleocene of North Sea and Norwegian Sea basins over several decades have led to the consistent recognition of six distinctive species of organic-walled dinoflagellate cyst genus Spiniferites. These species, however, have not previously been formally described, a situation that we remedy herein. Hence, we propose the new species Spiniferites fentonii, Spiniferites rhomboideus, Spiniferites truncatus, Spiniferites sabulus, Spiniferites kirschii and Spiniferites dolichoidus. These new species have distinctive morphological features that separate them, from other species, both of Spiniferites and other genera. Some of the new species are very useful stratigraphic markers across north-western Europe. The material described is from the early Thanetian Lista Formation and a late Danian interval including the basal Maureen Formation and parts of the Våle Formation. The new species have not been observed in the Selandian (between the Danian and Thanetian), and Spiniferites diversity during that stage seems to have been lower in general across the study area; this was probably related to regional environmental changes. The stratigraphic range of the new species is used in combination with other known markers to increase stratigraphic resolution across the region.

Spatio-temporal dynamics of hydrographic reorganizations and iceberg discharges at the junction between the Northeast Atlantic and Norwegian Sea basins surrounding Heinrich event 4

Dansgaard–Oeschger and Heinrich events constitute ones of the most enigmatic features of the last glacial period. Many studies have focused on their characteristic millennial climatic variability, testing atmospheric/cryospheric/oceanic couplings, but major uncertainties and discrepancies still remain. A new scenario, robustly supported by an approach coupling paleoreconstructions and freshwater hosing experiments simulating Heinrich-type perturbations, has recently emerged. Reconciling most of the up to now hypothesized theories, it suggests the occurrence of a regional seesaw between a cooled-down North Atlantic Ocean and warmed-up Nordic Seas during cold atmospheric phases, in relation to enhanced subsurface advection of warm Atlantic waters re-emerging in the Norwegian Sea. The associated ocean warming, thus reaching Nordic basins at a critical location beyond the Faeroe-Shetland sill, is proposed to be involved in the concomitant release of European icebergs. Here we further investigate this promising scenario over the 35–41 ka BP interval by (i) outlining its precise spatial pattern in a crucial area, i.e. the junction between the North Atlantic and the Norwegian Sea close to European ice-sheets, (ii) resolving its very fine temporal and regional evolution during critical transitions associated with the onset of warm advection, i.e. Greenland Interstadial to Greenland Stadial and Greenland Interstadial to Heinrich Stadial, and (iii) assessing its impact on the spatio-temporal dynamic of iceberg discharges from the European and Laurentide ice-sheets during cold stadial episodes especially including Heinrich event 4.

Oil and gas bearing in Norwegian Sea basins

The Norwegian passive continental margin is represented by an extensive gentle shelf and continental slope. On the continental slope, there are the isolated Voring, More and Ras basins, the Halten Terrace is situated to the east of them at the shelf, then the Nordland submarine ridge and the Trondelag Platform at the seaboard. There are Paleozoic, Mesozoic and Cenozoic sediments in its sections. Two complex structures are clearly distinguished in the sedimentary section: the lower stage (up to the Upper Cretaceous), reflecting the rifting structure of the basins, broken by a system of dislocations to a series of horsts, grabens, and separated blocks; and the upper stage, poorly dislocated, like a mantle covering the lower stage, with erosion and sharp unconformity. The Halten Terrace is the principal oil and gas production basin. At present, there are more than 50 oil, gas, and condensate fields in it. The following particularities have been discovered: than the field lays in the deepwater, than the age of the hydrocarbon pay is younger. It is also interesting that all gas fields are situated in the Voring and More basins and western part of the Halten Terrace; the oil and gas fields, mainly at the center of the Halten Terrace; but pure oil fields, in the north of the terrace. In conformity with discovering the particularities, it is possible to say that the prospects of oil and gas bearing in the Norwegian Sea are primarilyt related to the Halten Terrace and the Voring and More basins, especially the territories situated at the boundary of the two basins, where it is possible to discover large hydrocarbon accumulations like the Ormen-Lange field, because the Paleocene-Upper Cretaceous productive turbidite thick at the boundary of these basins is on the continental slope, which is considered promising a priori.

Oil and Gas Bearing of the Norwegian Sea Basins

Oil and Gas Bearing of the Norwegian Sea Basins

Modelling secondary production in the Norwegian Sea with a fully coupled physical/primary production/individual-based Calanus finmarchicus model system

The copepod Calanus finmarchicus is the dominant species of the meso-zooplankton in the Norwegian Sea, and constitutes an important link between the phytoplankton and the higher trophic levels in the Norwegian Sea food chain. An individual-based model for C. finmarchicus, based on super-individuals and evolving traits for behaviour, stages, etc., is two-way coupled to the NORWegian ECOlogical Model system (NORWECOM). One year of modelled C. finmarchicus spatial distribution, production and biomass are found to represent observations reasonably well. High C. finmarchicus abundance is found along the Norwegian shelf-break in the early summer, while the overwintering population is found along the slope and in the deeper Norwegian Sea basins. The timing of the spring bloom is generally later than in the observations. Annual Norwegian Sea production is found to be 29 million tonnes of carbon and a production to biomass (P/B) ratio of 4.3 emerges. Sensitivity tests show that the modelling system is robust to initial values of behavioural traits and with regards to the number of super-individuals simulated given that this is above about 50,000 individuals. Experiments with the model system indicate that it provides a valuable tool for studies of ecosystem responses to causative forces such as prey density or overwintering population size. For example, introducing C. finmarchicus food limitations reduces the stock dramatically, but on the other hand, a reduced stock may rebuild in one year under normal conditions.

New species of the genus Isorropodon (Bivalvia: Vesicomyidae: Pliocardiinae) from cold methane seeps at Nyegga (Norwegian Sea, Vøring Plateau, Storrega Slide)

A new species of vesicomyid bivalve (Isorropodon nyeggaensis sp. nov.) is described based on shell morphology, from the Nyegga cold methane seep area on the Norwegian continental margin. This is the first description of vesicomyids from the Norwegian Sea and the northernmost record of recent representatives of the family Vesicomyidae. A dispersion of the genus into the Norwegian Sea basin from the north-eastern Atlantic is suggested. A brief description of other macrofauna from methane seep sites at Nyegga is also given.

Decadal variability of the Arctic Ocean thermal structure

Long-term variability of heat content (HC) in the upper 1,000 m of the Arctic Ocean is investigated using surface and subsurface temperature and current data during 1958–2005 compiled by Simple Ocean Data Assimilation. Annual cycle of the Arctic Ocean HC is controlled primarily by the negative and positive excursions in net upper ocean heat flux, while the inter-annual variability is mainly associated with meridional thermal advection from the North Atlantic Ocean. Variability in HC is experienced as a basin-wide cooling/warming in association with the Arctic Oscillation on a decadal time scale. In the first three dominant modes of Empirical Orthogonal Function, the maximum amplitude of HC variability occurs in the Greenland–Norwegian Sea and Eurasian Basin. In general, HC showed increasing trend during 1958–2005 indicating continuous warming with regional variations in magnitude.

Upper ocean heat content in the Nordic seas

Seven years of temperature profiles are obtained from the Argo float project and are used to study the vertically integrated heat content for the Nordic seas which is broken up into the Norwegian Basin, Greenland Sea, Lofoten region, and Iceland Plateau. The World Ocean Atlas 2005 (WOA05) is used as the climatological baseline for temperature and hence heat content. Temporally and spatially averaged temperature profiles within the Norwegian and Iceland basins show good agreement between the Argo and WOA05 data sets. For the Greenland and Lofoten basins, the WOA05 data show cooler surface temperatures (by 1–2°C) but still lie within 1 standard deviation of each other over the 7‐year period. The Argo float data show circulation within each of the basins that is counterclockwise, and some of the floats eventually disperse toward the outer edges of the basins. Vertically integrated heat content from 0 to 1200 m shows similar characteristics as the WOA05 results including the timing and strength of the seasonal variability. The anomalous heat content for the Greenland and Norwegian sea basins is calculated in depth bins of 400 m. The Greenland Sea shows a warming trend over the 7 years of study, which corresponds to a temperature increase of (4.1 ± 0.3) × 10−2 °C/yr. The Norwegian Sea basin shows interannual variability in heat content for the surface layer (0–400 m) that may be related to the North Atlantic Oscillation (NAO). During an NAO+ phase, the Norwegian Basin shows a warm phase, and during an NAO− phase, the Norwegian Basin is in a cold phase; the correlation is small (r = 0.32) but different from zero correlation only at the 90% level, implying that the variability in the AHC may be due to (1) local atmospheric forcing and hence changes in heat loss, (2) atmospheric pressure differences that are not resolved by the NAO index, and (3) exchange of heat with the basin boundaries.

Development and mass movement processes of the north-eastern Storegga Slide

The Storegga Slide, which occurred ∼8100 years ago, is one of the world's largest and best studied exposed submarine landslides. In this study we use novel geomorphometric techniques to constrain the submarine mass movements that have shaped the north-eastern Storegga Slide, understand the link between different forms of failure, and propose a revised development model for this region. According to this model, the north-eastern part of the Storegga Slide has developed in four major events. The first event (event 1) was triggered in water depths of 1500–2000 m. In this event, the surface sediments were removed by debris flows and turbidity currents, and deposited in the Norwegian Sea Basin. Loading of the seabed by sediments mobilised by the debris flows and turbidity currents resulted in the development of an evacuation structure. Loss of support associated with this evacuation structure, reactivation of old headwalls and seismic loading activated spreading in the failure surface of event 1 up to the main headwall (event 2). In some areas, spreading blocks have undergone high displacement and remoulding. Parts of the spreading morphology and the underlying sediment have been deformed or removed by numerous debris flows and turbidity currents (event 3). We suggest that the higher displacement and remoulding of the spreading blocks, and their removal by debris flows and turbidity currents, was influenced by increased pore pressures, possibly due to gas hydrate dissolution/dissociation or by lateral variability in the deposition of contourite drifts in palaoeslide scars. The fourth event entailed a large, blocky debris flow that caused localised compression and transpressive shearing in the southern part of the spreading area.

Saucer-shaped intrusions: Occurrences, emplacement and implications

Magmatic intrusions and fluidized injected sands represent the two main types of sheet intrusions in the Earth's crust. In this paper we show that both intrusion types often display a saucer-like geometry, as revealed by 3D seismic imaging and field observations. Saucer-shaped intrusions are fairly common in sedimentary basins, as for example offshore in the Norwegian and North Sea basins and onshore in the Karoo Basin of South Africa. The formation of the saucer geometry is controlled by the low-viscosity of the injected fluid and by the interaction between a growing shallow hydraulic fracture and overburden deformations. Statistics gathered from observations and modelling show a linear relationship between the depth of emplacement and the size of the saucer-shaped intrusions. We anticipate future cross-disciplinary studies aiming to discover other occurrences of saucer-shaped intrusions and to identify the physical processes controlling the development of this fundamental geometry.

Miocene deep-water agglutinated foraminifera from ODP Hole 909c: Implications for the paleoceanography of the Fram Strait Area, Greenland Sea

Deep-water agglutinated Foraminifera (DWAF) are investigated from Miocene sediments recovered from ODP Hole 909C in the Fram Strait, Norwegian-Greenland Sea. We studied 125 samples from Cores 909C-50R to -103R, and recovered over 60 species of DWAF. The faunal succession in Hole 909C is subdivided into three assemblages based on the stratigraphic ranges of charac- teristic cosmopolitan taxa. These are: (1) a diverse Reticulophragmium amplectens - Reophanus berggreni Assemblage in Cores 909C-100R-2 to -91R-1 (1040.71-952.78mbsf); (2) a Reticulophragmium amplectens Assemblage in Cores 909C-87R-2, to -71R-3 (915.7-762.68mbsf); and (3) a low-diversity Reticulophragmium rotundidorsatum Assemblage in Cores 909C-71R-1 to -55R-1 (759.68-605.52mbsf). The DWAF assemblages are correlated to the standard chronostratigraphy using dinoflagellate cysts and magnetostratigraphy. The stratigraphic ranges of some well-known Paleogene DWAF species extend far into the Miocene at this local- ity, confirming the hypothesis that the Arctic and northern Norwegian Sea basins served as a refuge for these species long after they dis- appeared from the North Atlantic stratigraphic record. The taxonomic affinities of the Miocene assemblages from Hole 909C supports the idea that an estuarine circulation pattern has been in place between the Arctic Ocean and Greenland Sea basins since at least the early Miocene. Changes in the benthic foraminiferal morphogroups within the R. rotundidorsatum Assemblage correlate with an increase in total organic carbon, indicating an increase in oceanic productivity in the Fram Strait region during the late Miocene.

231Pa and 230Th in surface sediments of the Arctic Ocean: Implications for 231Pa/ 230Th fractionation, boundary scavenging, and advective export

Activities of 231Pa and 230Th in surface sediments from the Arctic Ocean and Greenland–Norwegian Seas are used to examine the redistribution of these water-column produced tracers between the low productivity interior basins and high particle flux marginal areas. Sediment 231Pa xs/ 230Th xs ratios throughout the Canadian and Eurasian Basins and the high particle flux Chukchi slope region are essentially invariant (average = 0.063 ± 0.014, N = 39) and significantly below the water column production ratio (0.093). 231Pa xs/ 230Th xs ratios are also below the production ratio in the seasonally high productivity Greenland–Norwegian Sea basins (average = 0.082 ± 0.024, N = 13), though they are ∼ 30% higher than the interior Arctic. The low sediment 231Pa xs/ 230Th xs ratios are attributed to the net export of ∼ 39% of dissolved 231Pa produced in intermediate/deep waters, as opposed to ∼ 10% of 230Th, through Fram Strait. The negligible 230Th export, combined with the reported low 230Th xs inventory of basin sediments and high 230Th xs inventory in Chukchi slope sediments, points to significant boundary scavenging of 230Th in the Arctic. The invariant 231Pa xs/ 230Th xs ratios further indicate that scavenging of 230Th is comparable to 231Pa (i.e., fractionation to a similar degree between the two nuclides) in both the interior basins and margins. Thus, while significant boundary scavenging of both 231Pa and 230Th occurs in the Arctic, there is a distinct lack of basin-margin fractionation and a sizable export of 231Pa. There is also likely to be export of other similarly particle-reactive radionuclides (e.g., 10Be, Pu isotopes) out of the Arctic.

Cretaceous and Palaeogene turbidite systems in the North Sea and Norwegian Sea Basins: source, staging area and basin physiography controls on reservoir development

The Cretaceous and Palaeogene succession in the North Sea and Norwegian Sea basins show widely variable deep-water sedimentary systems in terms of processes, facies, geometries, scale and distribution. The primary controls on the large-scale variability are considered to be source area size, basin and basin margin physiography and bathymetry, tectonic history and resulting morphology of drainage and delivery systems of sediments to deep-water areas, and the rate of sediment delivery. The North Sea and Norwegian Sea basins were comparable during the earliest Cretaceous, but thereafter developed in widely different ways as a response to proximity to oncoming North Atlantic seafloor spreading. In the North Sea Basin, the Cretaceous and Palaeogene turbidite systems were controlled by an inherited structural template from Late Jurassic rifting, and by source area size. Poorly developed or small drainage systems on the Norwegian margin and the broad Horda Platform gave little sand supply from the east to the Viking Graben area. Sand-rich systems were sourced from a relatively large hinterland and shallow marine staging area on the East Shetland Platform. North of the Horda Platform, sand supply was abundant in very discrete periods, particularly in the Early Eocene. In the Norwegian Sea basins, the Late Jurassic structural template controlled Early Cretaceous deep-water sedimentary systems in a manner similar to the North Sea Basin. Generally small and poorly developed drainage systems caused development of mud-rich systems. In contrast, in the Late Cretaceous, onset of precursor tectonic activity to sea-floor spreading led to increased sand supply from the west into the Vøring Basin. A relatively narrow palaeoshelf and a large source area contributed to forming sand-rich systems. Smaller turbidite systems developed along the Norwegian margin, which were sourced from the east from smaller drainage areas, and partially across broad shelves, such as the Trøndelag Platform. Both in the Cretaceous and Palaeogene, the sandiest systems are found only to the south and the north of the inherited structural features.

Gas exploration beyond the shelf break: An oceanographic challenge

Norway's second largest gas field, Ormen Lange, is located 140 km west off Kristiansund at an unprecedented depth when it comes to exploration. It will be the first Norwegian project beyond the shelf break. Exploration and development of the field is thus a challenge. An important issue during the planning stage is to understand the current conditions and hydrography of the site. This is especially important regarding pipeline design, deployment and operations. A complicating factor for estimating design currents is the extreme roughness of the local topography. Submarine slides have produced escarpments and sea mounts with height variations of up to 100 m. The hydrography seems to be equally complex; in situ moorings have revealed strong variations in current speed and temperature close to the seabed. A variety of numerical experiments have been and are being set up in order to recapture and if possible forecast the observed variability. The results show that the flow is influenced by the inflow of Atlantic Water, tides, atmospheric forcing and by flow of water masses inside the Norwegian Sea basin. The variability near the seabed at Ormen Lange is strongly influenced by the local topography and the stratification. Realistic model studies therefore require high resolution models for the Ormen Lange topography connected to basin scale models. The models must be non-hydrostatic and the stratification realistic to enable realistic estimates of extreme events.

Cenozoic evolution of the Faroe Platform: comparing denudation and deposition

Abstract Throughout Paleocene and Eocene time the Faroe-Shetland Channel and the eastern part of the Faroe Platform was a subsiding marine basin. In Early Paleocene time, basin-floor fans of a British provenance were deposited in the eastern part of the basin. In Late Paleocene time, c. 6 km of basalt entered the basin from the west and north, and the basin was constricted by the large volumes of basalt that entered the basin, creating the Faroe-Shetland Escarpment. In Eocene time subsidence continued in the basinal areas. Again, sediments of a dominantly eastern provenance were deposited. Throughout Eocene time, erosion products from the Faroe Platform were possibly deposited in the Faroe Bank Channel and the Norwegian Sea Basin, but only to a limited degree in the Faroe-Shetland Channel. The oldest sediments of documented western provenance on the eastern margin of the Faroe Platform are of Early Oligocene age. During a compressional phase commencing in Mid-Late Miocene time some basinal areas emerged and erosion took place on the top of emerged anticlines. However, denudation throughout Late Miocene and Early Pliocene time was apparently rather limited compared with a Late Pliocene phase of denudation. During this phase of denudation, a large progradational wedge was deposited on the eastern margin of the Faroe Platform. On the basis of a structural analysis of the Faroe Platform, the amount of basalt removed from it during Cenozoic time is estimated to be c. 46 000 km 3 (131 100 × 10 12 kg). Using 2900 kg m −3 as the density of basalt and 2300 kg m −3 as sediment density the estimated amount of removed basalt is in fair agreement with the estimate of the volume of sediments derived from the platform ( c. 56 000 km 3 , 114 800 × 10 12 kg). The greatest deposition rates on the eastern Faroe Platform and in the Faroe-Shetland Channel apparently occurred after two distinct inversion or compression events in Mid-Eocene and Mid-Late Miocene time. However, uplift of the Faroe Platform could have been forced by denudation rather than endogenous processes.

The distribution of Cretaceous and Paleocene deep-water reservoirs in the Norwegian Sea basins

Facies maps for selected Cretaceous and Paleocene deep-water sandstone reservoirs in the Norwegian Sea constitute an exploration tool and allow description of the basin infill in relation to tectonic phases. Sequences K40 (middle–late Albian) and K60 (middle–late Cenomanian) formed in an immature basin where most of the fan systems and slumps were derived from local highs. Sequence K80 (Coniacian–late Santonian) contains sandstones interpreted to be slumped deposits in parts of the Halten and Dønna terraces (Lysing Formation), but with fans of widespread extent in the Vøring and northern Møre Basin. The K85–K90 sequence set (early Santonian–late Campanian) contains sandstones equivalent to the Nise Formation that are the main potential reservoirs in the Vøring Basin; they were fed by multiple entry points and developed into areally extensive basin floor thicks. Sequence Pg10 (Danian–Selandian: ‘Egga’ Member) is interpreted to comprise a basin floor fan in the Ormen Lange discovery. During this cycle the Halten Terrace rotated eastwards exposing Upper Cretaceous mudstones. Vast amounts of sediment were deposited in the western Møre and Vøring Basin around new exposed areas.

Late Quaternary slope instability on the Faeroe margin: mass flow features and timing of events

Deep-tow side-scan sonar, sub-bottom profiling and sediment core data reveal that, since the last interglacial, mass flows repeatedly occurred both on the northeastern Faeroe margin and on the Faeroes slope of the Faeroe-Shetland Channel. In both areas, the last two slope instability episodes are dated at the Pleistocene/Holocene boundary and at the Last Glacial Maximum (LGM), i.e. during times of fast sea-level rise and increasing bottom current activity, and glacio-eustatic lowstand, respectively. A major fine-grained turbidite found in the Norwegian Sea basin off the Faeroe margin may be correlated with the LGM event. Several distinctive mass flow features have been documented. These include, among others, large swarms of debris flow 'glide' tracks with outrunner blocks found on the seabed of the northeastern Faeroe margin. It was concluded that the age of the latter features is not older than the LGM.

Dissolved gallium in the Atlantic Ocean

Abstract Gallium is geochemically similar to aluminum, though less reactive. As such, gallium is potentially useful to resolve questions about the aluminum distribution. Dissolved gallium data from 14 profiles in the Atlantic Ocean as well as additional surface water samples are presented here. The results verify that the main delivery of gallium to the surface ocean is aeolian and that gallium has a surface water residence time longer than aluminum but probably similar to manganese (i.e., order of decades). Surface water gallium concentrations in the Sargasso Sea are unusually high (>40 pmol kg −1 ). There is likely an anthropogenic component in the Sargasso Sea, but residence time effects may also be at work. Dissolved gallium profiles in the Atlantic are generally similar to those of aluminum. The subsurface gallium maximum previously observed in the northeast Pacific is not found, but may be obscured by advective features in the Atlantic. Deep waters in the Atlantic show generally conservative behavior of gallium, supporting the concept of using aluminum as a deep water tracer in the Atlantic. However, gallium enrichments are observed in the deep waters of the Norwegian Sea and Iceland Basin. A consideration of possible sources of these enrichments suggests that release from resuspended sediments is the most likely source mechanism.

Chapter 11 Southern Svalbard:Bjørnøya and submarine geology

The area south of Spitsbergen (about 76°31'N) to latitude 74°N, and between longitudes 10°E and 35°E, by which Svalbard was first defined, contains the small island of Bjørnøya (Bear Island, Bären Insel) and the rest is sea (Fig. 11.1). The 500 m isobath conveniently separates the edge of the Barents shelf from the Norwegian Sea Basin which runs south from Spitsbergen between 14° and 16°30'E. To the east, the large shallow area, Spitsbergenbanken, less than 100 m deep, supports Bjørnøya at its southwestern end, extends northeast to Hopen and joins Edge°ya. It is separated from Spitsbergen to the north by the Storfjordyrenna and to the east by Hopendjupet. These submarine valleys appear to drain westwards into the ocean deep with deltaic fronts convex westward. This chapter focuses first on Bjørnøya which though small is a key outcrop in the Barents Sea and distinct in many respects from Spitsbergen being about 250 km distant. The chapter then surveys a little of what is known of the surrounding sub-sea area. Bjørnøya (20 km N-S and 15 km E-W), as the southern outpost of Svalbard, has long been a key to Svalbard geology since it is generally free all year from tight sea ice. But though its location is convenient, its cliffs generally bar access. Indeed there are very few places where landing by other than inflatable dinghy are feasible. After the island had been claimed by a Norwegian syndicate in 1915 mining of Tournaisian coal began in 1916 and exported over 116000