Structure and heat content of the West Spitsbergen Current

The seasonal evolution of the hydrographic structure of the West Spitsbergen Current (WSC) above bottom depths from 300 m to 800 m is discussed based on a modern data set with high spatial resolution. The WSC appears to have a core with high temperature and salinity, linked to the topography in this depth interval, with a width on the order of 10 km. Strong cooling occurs in the autumn, reducing the heat content of the upper 200 m, but advected temperature and salinity maxima survive close to the surface in spring when air-sea exchange and vertical mixing is hampered by sea ice and meltwater.     

Driftwood as an indicator of relative changes in the influx of Arctic and Atlantic water into the coastal areas of Svalbard

A total of 276 driftwood samples from Wijdefjorden on the northern coast of Spitsbergen were den-drochronologically analysed and compared with results from a similar study on driftwood from Isfjorden. The composition and origin of the driftwood from the two places differ. Whereas Larix is almost absent in the Isfjorden driftwood, it comprises 25% of the Wijdefjorden collection. The Isfjorden driftwood has its main origin in the White Sea region and the dates of the driftwood concentrate around the period from 1950 to 1979, with only a few dates from the period 1910 to 1950. The Wijdefjorden driftwood has two main origins: Siberia and the White Sea region. The dates of the White Sea components of the Wijdefjorden driftwood are concentrated mainly in the period 1910-1950. The dates of the Siberian (Yenisey) components of the Wijdefjorden driftwood are concentrated in the period 1950–1979. It can be argued that during the time period from ca. 1910 to 1950 the activity of a warm northerly flowing current along the western coast of Spitsbergen was stronger, transporting White Sea driftwood all the way to the Wijdefjorden area. However, after ca. 1950 the input of White Sea driftwood decreased, and the relative importance of the Siberian component increased. These results fit well with the climatic records from Svalbard, showing a warm regime during the first half of this century due to increased activity of the warm West Spitsbergen Current along the western coast of Spitsbergen. After ca. 1950, the influx of Atlantic Water became weaker, the climate became colder and the relative occurrences of Siberian driftwood transported by the Transpolar Current increased on the northern coast of the Svalbard archipelago.     

Direct measurements of volume transports through Fram Strait

Heat and freshwater transports through Fram Strait are understood to have a significant influence on the hydrographic conditions in the Arctic Ocean and on water mass modifications in the Nordic seas. To determine these transports and their variability reliable estimates of the volume transport through the strait are required. Current meter moorings were deployed in Fram Strait from September 1997 to September 1999 in the framework of the EU MAST III Variability of Exchanges in the Northern Seas programme. The monthly mean velocity fields reveal marked velocity variations over seasonal and annual time scales, and the spatial structure of the northward flowing West Spitsbergen Current and the southward East Greenland Current with a maximum in spring and a minimum in summer. The volume transport obtained by averaging the monthly means over two years amounts to 9.5 ± 1.4 Sv to the north and 11.1 ± 1.7 Sv to the south (1 Sv = 10⁶ m³s⁻¹). The West Spitsbergen Current has a strong barotropic and a weaker baroclinic component; in the East Greenland Current barotropic and baroclinic components are of similar magnitude. The net transport through the strait is 4.2 ± 2.3 Sv to the south. The obtained northward and southward transports are significantly larger than earlier estimates in the literature; however, within its range of uncertainty the balance obtained from a two year average is consistent with earlier estimates.     

Outflow of Pacific water from the Chukchi Sea to the Arctic Ocean

Pacific water exits the Chukchi Sea shelf through Barrow Canyon in the east and Herald Canyon in the west,forming an eastward-directed shelfbreak boundary current that flows into the Beaufort Sea.Here we summarize the transformation that the Pacific water undergoes in the two canyons,and describe the characteristics and variability of the resulting sbelfbreak jet,using recently collected summertime hydrographic data and a year-long mooring data set.In both canyons the northward-flowing Pacific winter water switches from the western to the eastern flank of the canyon,interacting with the northward-flowing summer water.In Barrow canyon the vorticity structure of the current is altered,while in Herald canyon a new water mass mode is created.In both instances hydraulic effects are believed to be partly responsible for the observed changes.The shelfbreak jet that forms from the canyon outflows has distinct seasonal configurations,from a bottom-intensified flow carrying cold,dense Pacific water in spring,to a surface-intensified current advecting warm,buoyant water in summer.The current also varies significantly on short timescales,from less than a day to a week.In fall and winter much of this mesoscale variability is driven by storm events,whose easterly winds reverse the current and cause upwelling.Different types of eddies are spawned from the current,which are characterized here using hydrographic and satellite data.     

Across the Arctic front west of Spitsbergen: high-resolution CTD sections from 1998-2000

The structure of the oceanic Arctic front west of Spitsbergen is investigated using data from high-resolution CTD sections from September 1998-2000. Below the fresher surface layer, the front appears as a temperature-salinity front situated near the shelf break. No clear corresponding front in density is found. Our analysis suggests that barotropic front instability is a main factor in provoking subsurface cross-front exchange. The subsurface heat loss in the West Spitsbergen Current due to this exchange is estimated to be of the same order of magnitude as the heat loss to the atmosphere in the surface layer.     

Physiological adaptations in Coleoptera on Spitsbergen

Metabolic rates and Q₁₀ values were determined for three species of Spitsbergen Coleoptera, Amara quenseli, Simplocaria metallica and Rhynchaenus flagellum . The beetles had metabolic rates which were elevated compared to values of Coleoptera from other regions. This is interpreted as an adaptation to the prevailing low temperatures and short activity period on Spitsbergen.
A. quenseli had rates of water loss comparable to values of beetles in temperate and tropical xeric habitats, indicating that the habitat of the beetles on Spitsbergen at least occasionally is xeric.
Determination of cold-hardiness parameters such as supercooling point and haemolymph melting point of A. quenseli beetles revealed that the beetles had values corresponding to those of active insects in the temperate and tropical region. They had no thermal hysteresis factors. Thus, during summer they show no physiological adaptations to cold.     

Grenvillian U-Pb zircon ages of quartz porphyry and rhyolite clasts in a metaconglomerate at Vimsodden, southwestern Spitsbergen

Proterozoic metasupracrustal rocks form a NNW-SSE trending basement zone along the western coast of Spitsbergen. The rocks show complex structures as a result of both Caledonian and Tertiary deformation, and most of the subordinate metaigneous rocks are not suitable for isotopic age determination. Some zircon-bearing rocks were found in the southwestern part of Spitsbergen and an attempt of U-Pb dating was performed.
U-Pb dating was carried out on zircon fractions from quartz porphyry and rhyolite clasts in a metaconglomerate unit of the Pyttholmen Formation northwest of Hornsund, southwestern Spitsbergen. The Pyttholmen Formation is considered to be a lateral equivalent of the upper part of the Gulliksenfjellet quartzite and in the same time as the upper part of the Skålfjellet metavolcanites. Therefore, the obtained ages are applicable to the age of the Skålfjellet igneous activities. Some of the dated samples are strongly schistose and their magmatic origin is difficult to confirm; the interpretation of the isotopic results is not well constrained; however, some explanations are possible which refer to the known geological conditions; an igneous age of siliceous volcanic rocks of ca. 1200 Ma, inherited zircon ages of ca. 2500 Ma and a regional metamorphic age of ca. 930 Ma. The last age belongs to the Grenvillian period and is conformable with the Rb/Sr whole rock age obtained from the garnet-biotite schists of the Isbjernhamna Group underlying the Skålfjellet metavolcanites.     

Structure of relief of continents in the river network pattern

The hydrographic network structure of continents conveys the chief peculiarities of relief of mainland at the planetary level of organization. In eastern Eurasia, it is a general northward ramp occupying the entire Siberian part of Russia and the central elevation of the Tibetan Plateau and extending further in the form of Arctic shelves. The other continents are characterized by some elevation of their marginal parts, and by the presence of central basins with hydrographic nodes and rivers, or catchments.     

Analysis of the structure of river systems and the prospects for modeling hydrological processes

We consider the results derived in Russia from investigating the structure of river systems for the period 1960–1980. Some generally available sources of digital models of the relief, and the main algorithms for processing them are described. We provide an example of analyzing the hydrographic network of the Komarovka river basin in order to develop the technique of objective digitizing and correct determination of a first-order water stream.     

Volume, heat and salt transport by the West Spitsbergen Current

During the summer of 2000 (June-July) 14 CTD and ADCP transects perpendicular to the West Spitsbergen Current and along the western border of the Barents Sea were made. The measurements covered the area between 69° 43'and 80° N and 01° and 20° E. The main purpose was to follow changes in volume, heat and salt content of Atlantic Water (AW) on its way north. The strongest and most stable flow of AW was located along the continental slope where northward flowing currents exceeding 40 cm/sec were measured. A few weaker northward branches were also found to the west of the slope. South-directed currents were recorded between them and eddy-like mesoscale structures were commonly observed. Measured by vessel-mounted acoustic Doppler current profiler (VM-ADCP), the net northward transport of AW volume in the upper 136 m layer decreased from nearly 6 Sv at the southernmost transect to below 1 Sv at a latitude of 78° 50'N. Similarly, heat transport drops from about 173 TW to about 9 TW and relative salt transport (over 34.92 psu) from 980 × 10³ kg/sec to 14 × 10³ kg/sec. Transport in the southern direction prevails at the transect located between 79° 07'and 79° 30'N. The calculated baroclinic geostrophic transport of AW volume, heat and salt in the upper 1000 m layer behaves similarly. East-directed transport dominates at the Barents Sea boundary while westward flow prevails on the western side of the West Spitsbergen Current.     

Heavy metals in water, ice and biological material from Spitsbergen, Svalbard

Concentrations of heavy metals Zn, Mn, Cu, Fe, Ni, Cr, Pb, Cd, Hg and Co were determined in surface waters, glacier ice and plant and animal materials from three regions in Spitsbergen, Svalbard. The concentrations of these metals in two samples of surface waters and in the vascular plants from Spitsbergen were found to be lower than what is commonly found in Cental Europe. Elevated concentrations were found in old ice from the surface of a glacier. The concentrations of heavy metals in algae were lower than in vascular plants. The concentrations of metals in the samples of feathers and animal hair from Spitsbergen were higher than what is common for Central Europe.     

Snow accumulation, melt, mass loss, and the near-surface ice temperature structure of Irenebreen, Svalbard

This study examines the mass balance, accumulation, melt, and near-surface ice thermal structure of Irenebreen, a 4.1 km² glacier located in northwest Spitsbergen, Svalbard. Traditional glaciological mass balance measurements by stake readings and snow surveying have been conducted annually at the glacier since 2002, yielding a mean annual net mass balance of −65 cm w.e. for the period 2002–2009. In 2009, the annual mass balance of Irenebreen was −63 cm w.e. despite above-average snow accumulation in winter. The near-surface ice temperature in the accumulation area was investigated with automatic borehole thermistors. The mean annual surface ice temperatures (September–August) of the accumulation area were −3.7 °C at 1 m depth and −3.3 °C at 10 m depth. Irenebreen is potentially polythermal, with cold ice and a temperate surface layer during summer. This temperate surface layer is influenced by seasonal changes in temperature. In winter, the temperature of all the ice is below the melting point and temperate layers are probably present in basal sections of the glacier. This supposition is supported by the presence of icings in the forefield of Irenebreen.     

Thermal regime of a valley glacier, Erikbreen, northern Spitsbergen

The thermal regime of the valley glacier, Erikbreen, northern Spitsbergen (79°40'N, 12°30'E) was studied using radio-echo sounding and temperature measurements from eight boreholes ranging from 13.5 to 24 m. Radar images indicate a glacier with a two-layered thermal structure. A surface layer of cold ice, 20 to 60 m thick along the centre flow line, extends from an altitude above equilibrium line to the glacier front. This layer represents 20 to 35% of the glacier thickness, except at the floating front, where the cold layer is about 50%. The ice beneath the cold surface layer is interpreted to be temperate. Cold-based areas exist near the glacier margin and in some locations in the accumulation area; the ice is interpreted to be entirely temperate in central parts of the accumulation area at high altitude. Freezing of temperate ice at the base of the cold surface layer is probably the main mechanism of cold ice formation in the frontal parts of Erikbreen. Calculated heat fluxes based on the borehole measurements show that a steady state cold layer 25 to 30 m thick is likely, assuming a surface melting of 1.7 m/y and a maximum water content of 3%. In the frontal parts the calculated mean annual upward heat flux at 10 to 15 m depth is roughly 0.6 W/m².     

Palynology of two 4500 year old skua-mounds of the Arctic Skua (Stercorarius parasiticus (L.)) in Svalbard

Skuamounds are peaty hillocks up to 70 cm high used by Arctic Skuas (Stercorarius parasiticus (L.)) for surveying their breeding territory. Well-developed skua-mounds in Svalbard can be considered as small guanogenic bogs', because the peat formation depends on manuring by birds and the water-table in the mound is higher than the surrounding tundra. Peat sections measuring 34 cm and 40 cm from two skuamounds from Edgeøya and Spitsbergen were radiocarbon dated and studied for pollen and spores. Peat formation on the two skua-mounds started c. 4500 calendar years ago. Concentration values of longdistance transported pollen were used to detect time gaps in the records. The time gap in the skua-mound from Spitsbergen was found to be considerably greater than in the skuamound from Edgeøya. Erosion has progressed considerably further on the Edgeøya skua-mound than on the skua-mound from Spitsbergen due to differences in hydrology: the peat of the former mound is dry and unfrozen in summer, whereas in the latter mound it is wet and frozen. Time gaps and erosion are probably associated with phases of decreased manuring by birds. At two levels in the Edgeøya skua-mound there is evidence of a climatic change towards cooler conditions, one being an early major climatic shift and the other a later minor climatic shift. A similar major climatic shift is associated with one level in the skuamound from Spitsbergen.     

Acanthodian scales and worm tubes from the Kapp Kjeldsen Division of the Lower Devonian Wood Bay Formation, Spitsbergen

Results of a thin section study of bonebeds from the Kapp Kjeldsen Division are presented and discussed. The material for this study was collected in the talus on the south-eastern side of Bockfjorden, northern Spitsbergen. The stratigraphical position of the Kapp Kjeldsen Division within the Devonian strata of Spitsbergen is shown in Table 1.
The thin sections for this study were not made to standard thickness, but are slightly thicker for better resolution of the vertebrate material. Each thin section was individually polished. The photos are made with crossed nichols.     

The Wilhelmøya Formation (Upper Triassic-Lower Jurassic) at Bohemanflya, Spitsbergen

An 18.5 m thick shale sequence of Norian-Rhaetian age is described from the Bohemanfiya-Syltoppen area (north of Isfjorden, central Spitsbergen). Lithological, petrographical and palynological analyses show that the sequence represents a marginal development of the lower part of the Wilhelmeya Formation. The depositional history at the Triassic-Jurassic transition is discussed in the light of this new evidence. The Wilhelmøya Formation was probably deposited during a weak marine transgression over an area of low relief. Low sediment supply and current and wave reworking of the sediments characterized the depositional conditions.     

Age of Tertiary formations on Spitsbergen

Biostratigraphic evidence for the age of Tertiary formations on Spitsbergen is critically reviewed and new evidence from dinoflagellates is presented. The shift in basin geometry and sediment source area observed in the Gilsonryggen Formation is dated as latest Palaeocene, coinciding with the initial opening of the Norwegian Sea at anomaly 24–25 time. An Upper Eocene age is proposed for sediments from Forlandsundet (Sarsbukta), indicating that the Forlandsundet graben was created during the phase of shear movement between Greenland and Spitsbergen before anomaly 13 time.     

The Triassic ammonite Aristoptychites kolymensis (Kiparisova) from Botneheia, Spitsbergen

Aristoptychites kolymensis (Kiparisova) is investigated and described in detail from collections made at Botneheia, Spitsbergen, where it occurs at the top of the Botneheia Formation (Daonella Shale). It is a rather small species and the stratigraphically highest representative of the genus in Spitsbergen. Its suture line is remarkable by its possession of the additional U.-lobes between the internal lobe and the first umbilical lobe. A lobe of this kind has so far been described only once, with Arcestes (Proarcestes) bicarinatus by Schindewolf (1968), which suggests affinities between Ptychitidae and Arcestidae.     

Glaciation development and interstadial sea-level on central Spitsbergen, Svalbard

Above the marine limit in Gangdalen, Nordenskiold Land, a 20 m thick sequence of unconsolidated sediments occurs. On the top of striated bedrock it is composed of a 2m thick till bed, 15m gravel interpreted to be deposited as a sandur, and another till bed on the top. A solifluction deposit is capping the section. Fabric analyses and erratics in the two tills indicate a similar development in glacial transport directions during the two glaciations, starting with a local glaciation which subsequently turns into a larger glaciation centred over the eastern part of Svalbard. Co-existence of different ice domes over Spitsbergen is suggested. The sandur was deposited during an ice free period with a sea-level 40–80 m higher than at present. The section is undated.