Polar Research (E-Journal)
Not a member yet
1388 research outputs found
Sort by
High-Arctic nesting geese occupying less favourable nest sites are more vulnerable to predation
No full textIn a simple, rodent-free Arctic ecosystem in Svalbard, we assessed the nest-site characteristics of the main (and highly abundant) migratory herbivore—pink-footed geese (Anser brachyrhynchus)—to determine which nesting geese were preferentially attacked and killed by the only local predator of adult geese, the Arctic fox (Vulpes lagopus). We collected data on goose carcasses and nest-site characteristics at one of the main pink-footed goose breeding areas in Svalbard. Arctic foxes depredated adult pink-footed geese from just over a quarter of the unsuccessful nests in the colony and carcasses were generally found just under 10 m away from a nest. Geese that occupied nests of poorer quality (limited visibility, further distance to forage patches and situated on flatter slopes) and were less well established (indicated by the low degree of fertilization from accumulations of goose droppings) were more likely to be depredated by Arctic foxes. As geese show a high degree of nest-site fidelity and preferentially occupy nests with better protection against depredation and closer to feeding areas, we propose that Arctic foxes targeted, and were more successful in killing younger, more inexperienced or low-quality geese that occupied less favourable nest sites
The marine sedimentary environments of Kongsfjorden, Svalbard: an archive of polar environmental change
No full textKongsfjorden, a fjord in north-western Svalbard, is characterized by large environmental gradients driven by meltwater processes along the margins of tidewater glaciers and the inflow of relatively warm Atlantic Water, the main heat source for the European Arctic. These factors make Kongsfjorden a key area to investigate changes in the polar climate–ocean–glacier system and to examine the resulting effects on the marine environment. The aim of this paper is to synthesize knowledge about the marine sedimentary environment in Kongsfjorden since the last deglaciation. Fjords act as natural sedimentary traps, archiving information about past and present environmental conditions and changes. Geological studies of Kongsfjorden have demonstrated a good potential for reconstructing palaeoenvironments and establishing baselines values for the natural climate changes in the Arctic. Palaeoceanographic reconstructions reveal rising water temperatures similar to modern temperatures ca. 12 000 years ago. The extent of warm Atlantic Water entering the fjords influences processes at, and the stability of, the margins of the tidewater glaciers. Enhanced inflow may cause accelerated glacial melting that, in consequence, leads to an increase in the sediment flux from the glacial catchments into the fjord, as observed ca. 12 000 years ago and at present. However, responses of sediment flux to modern environmental changes remain poorly understood, hence long-term and monitoring studies are needed to quantify and model the effects of climate warming on the sedimentary environment of Kongsfjorden
Monitoring glacier flow in Ny-Ålesund with a high temporal resolution ground-based interferometric-phased array radar
No full textMonitoring glacier flow speed and calving rates is of interest for climate research, global sea-level studies and Arctic ship traffic. The research station in Ny-Ålesund, Svalbard, offers a unique location close to multiple glacier fronts. In this study, we explore the possibilities of permanent monitoring of glaciers in the Ny-Ålesund area using a ground-based interferometric radar with a significantly higher temporal resolution than what is achievable from satellites or mechanical scanning ground-based radars. Measurements were made from two different locations—Pynten and the Ny-Ålesund research station—located 5 and 15 km from Kronebreen glacier, respectively. The temporal resolution of the radar is flexible, and in this experiment is limited to five images per minute, providing data with high temporal resolution of glacier flow. We calculated a geo-located two-dimensional flow map of the glacier from the radar data, extracted glacier speed profiles and identified major calving onsets. This type of near real-time data may well be used with machine-learning techniques for more advanced monitoring systems. The radar measurements agree well with previous satellite measurements at lower temporal resolution. The observed mean flow of the Kronebreen glacier front varies across the glacier from around 0.4 m/day at the edges to 3 m/day in the central part. We identify and discuss possible improvements to the radar system and conclude that Ny-Ålesund is a well-suited location for radar monitoring of glacier flow velocities
Temporal and spatial variability of stream water chemistry on Subantarctic Marion Island
No full textConcentrations of major ions in stream water from the Soft Plume River on Subantarctic Marion Island were measured. During the annual relief voyage, samples were collected daily over a 16-day period (21 April–6 May 2015) from three sites along the stream to better understand temporal and spatial variability of stream water chemistry on the island. The chemical composition of the stream is dominated by the sea salts Na+ and Cl−. Mean solute concentrations for Na+ and Cl− are 7 ± 0.58 and 12.5 ± 0.84 mg/L, respectively. The mean molar Na:Cl ratio for all samples is 0.86 ± 0.05, with a range from 0.71 to 0.99 (n = 47), and there is a strong, significant positive correlation between Na+ and Cl− concentrations (r = 0.80; p < 0.001). These values are consistent with previous studies from Marion Island and other Subantarctic islands. Temporal variation in ion concentrations was small. The largest detected change was a decrease in most solute concentrations that coincided with two precipitation events. This decrease was largest at the highest altitude and the shallowest site, suggesting that there was more rainfall at this location. These findings confirm the dominance of the surrounding ocean as the main source of the island’s stream water chemistry and illustrate spatiotemporal patterns that provide an insight into mechanisms affecting their composition on Subantarctic Marion Island
Indication of Holocene sea-level stability in the southern Laptev Sea recorded by beach ridges in north-east Siberia, Russia
No full textThe rapid warming of the Arctic may affect the stability of coastal geomorphological systems. Prograded sequences of wave-built deposits, so-called beach-ridge systems, preserve a proxy record of the long-term variability in the drivers of coastal evolution. Information on relative sea level (RSL), climate forcing and sediment supply can be reconstructed from these archives. Buor Khaya Bay is one of the few places along the Siberian Arctic coast where wide beach-ridge systems exist. A previously undescribed field site was surveyed in order to obtain information on the geomorphological processes along the modern shoreline under the current environmental conditions, and the characteristics of the Holocene beach-ridge deposits (e.g., elevation, sediment and age). Our data show that the system formed under storm wave/surge conditions. The beach ridges prograded ca. 1100 m between 6200 and 2600 cal yr BP, with only minor variations in surface elevation. This suggests a continuous and high sediment supply and similar storm wave run-up heights during that time. This relationship is interpreted as indicating RSL stability at a similar-to-present elevation during the period of beach-ridge formation. The hiatus in coastal progradation is concurrent with a deteriorating climate (cooling) in the Laptev Sea area and our data hence suggest increased rates of coastal change during periods of warmer climate conditions. Our study illustrates the potential of coastal sedimentary archives to provide a more complete view of the forcing, resilience and long-term evolution of unconsolidated Arctic coasts in a changing environment
Wintering seabirds in south-west Greenland, 2017
No full textThe South-west Greenland Open Water Area is an internationally important wintering area for seabirds in the North Atlantic. Nearly two decades after the area was last surveyed, we conducted a replicate aerial survey in March 2017 to update information on the distribution and abundance of seabirds. With a total effort of about 5800 km, we covered the coastal area from Aasiaat (69°N) to Kap Farvel (60°N), 56% of the open water area in the fjords, and the offshore bank, Store Hellefiskebanke. Line transect survey methodology was used except in the fjords, which were censused by total counts. By means of distance sampling analyses, the abundances of the dominant species were estimated to be roughly 1100 000 king eiders (Somateria spectabilis), 443 000 common eiders (Somateria mollissima), 42 000 long-tailed ducks (Clangula hyemalis) and 76 000 Iceland gulls/glaucous gulls (Larus glaucoides/Larus hyperboreus). For the great black-backed gull (Larus marinus), great cormorant (Phalacrocorax carbo), mallard (Anas platyrhynchos) and red-breasted merganser (Mergus serrator), we present the first winter population estimates for the area (6100, 7700, 7600 and 3200 individuals, respectively). Areas around Kangaatsiaq, Nuuk and Julianehåbsbugten were identified as key wintering sites, as was Store Hellefiskebanke which held 99% of the king eiders. For all species assessed in 1999, abundance in the coastal survey area was considerably lower in 2017. In some cases, this may be due to changes in distribution patterns. However, for thick-billed murre (Uria lomvia), long-tailed duck and black-legged kittiwake (Rissa tridactyla), the reduced coastal abundances coincide with declining breeding populations
Sedimentology and petrography of the Svenskøya Formation on Hopen, Svalbard: an analogue to sandstone reservoirs in the Realgrunnen Subgroup
No full textOn the island of Hopen, in the Svalbard Archipelago, the Svenskøya Formation is a succession 35 m in thickness, consisting primarily of sandstone beds and forming the youngest strata exposed on the island. We present a sedimentological and petrographic study of the formation and compare the unit with its exposures on Wilhelmøya and in Kong Karls Land, Svalbard. We also compare the onshore characteristics of the Svenskøya Formation with those of the Tubåen Formation, its time-equivalent unit in the Sentralbanken area of the northern Barents Sea. On Hopen, the Svenskøya Formation is interpreted as representing coarse clastic sediments deposited in a fluvial to tidal setting, prior to being overlain by a thin interval composed of tidal channel and marine shale deposits. The unit sits atop the regional “Rhaetian Unconformity” and represents sediments deposited during a regressive system that terminates at a flooding surface representing a local transgression of the palaeo-coastline. Petrographic studies show the formation as being arkosic, both on Hopen and in the Sentralbanken area. The reservoir quality of sandstone samples recovered from Hopen is somewhat lower compared to sandstone reservoirs in the Sentralbanken area. We attribute this to greater effects of diagenesis in the Hopen area, which caused increased compaction, mineral dissolution and extensive precipitation of pore-filling clay minerals
Seasonal dynamics of the marine CO2 system in Adventfjorden, a west Spitsbergen fjord
No full textTime series of the marine CO2 system and related parameters at the IsA Station, by Adventfjorden, Svalbard, were investigated between March 2015 and November 2017. The physical and biogeochemical processes that govern changes in total alkalinity (TA), total dissolved inorganic carbon (DIC) and the saturation state of the calcium carbonate mineral aragonite (ΩAr) were assessed on a monthly timescale. The major driver for TA and DIC was changes in salinity, caused by river runoff, mixing and advection. This accounted for 77 and 45%, respectively, of the overall variability. It contributed minimally to the variability in ΩAr (5%); instead, biological activity was responsible for 60% of the monthly variations. For DIC, the biological activity was also important, contributing 44%. The monthly effect of air–sea CO2 fluxes accounted for 11 and 15% of the total changes in DIC and ΩAr, respectively. Net community production (NCP) during the productive season ranged between 65 and 85 g C m−2, depending on the year and the presence of either Arctic water or transformed Atlantic water (TAW). The annual NCP as estimated from DIC consumption was 34 g C m−2 yr−1 in 2016, which was opposite in direction but similar in magnitude to the integrated annual air–sea CO2 flux (i.e., uptake of carbon from the atmosphere) of −29 g C m−2 yr−1 for the same year. The results showed that increased intrusions of TAW into Adventfjorden in the future could possibly lower the NCP, with the potential to reduce the CO2buffer capacity and ΩAr over the summer season
Review of The spectral Arctic: a history of dreams and ghosts in polar exploration by Shane McCorristine (2018). London: University College London Press. 265 pp. ISBN 978-1-78735-246-9.
No full textGiles Land—a mystery for S.A. Andrée and other early Arctic explorers
No full textAfter the initial discovery of Giles Land (Kvitøya, Svalbard) by Cornelis Giles in 1707, it was most likely never seen by anyone again until 1876. During this lengthy period, Giles Land evolved into an enigma as various explorers and cartographers came to very different conclusions about its probable location, character or even existence. In 1897, when the engineer Salomon August Andrée tried to return over the ice after his failed attempt to reach the North Pole in a balloon, he passed through an area approximately 160 km north of Kvitøya where Giles Land was indicated on his map. Andrée searched for it, but there was no land in sight. The main reason why Giles Land was erroneously positioned too far north was a conjecture by a German cartographer August Petermann in 1872. While there was some distrust of Petermann’s conjecture at the time, many also believed it. The erroneous understanding that Giles Land was located far north of Kvitøya was only finally dismissed in the 1930s. This article examines how this misunderstanding regarding the identity and location of Giles Land could arise and become entrenched