Опубликована Сен. 23, 2016
Ice-rich permafrost coasts often undergo rapid erosion, which results in land loss and release of considerable amounts of sediment, organic carbon and nutrients, impacting the near-shore ecosystems. Because of the lack of volumetric erosion data, Arctic coastal erosion studies typically report on planimetric erosion. Our aim is to explore the relationship between planimetric and volumetric coastal erosion measurements and to update the coastal erosion rates on Herschel Island in the Canadian Arctic. We used high-resolution digital elevation models to compute sediment release and compare volumetric data to planimetric estimations of coastline movements digitized from satellite imagery. Our results show that …
Опубликована Июнь 17, 2016
Changing environmental and geomorphological conditions are resulting in vegetation change in ice-wedge polygons in Arctic tundra. However, we do not yet know how microscale vegetation patterns relate to individual environmental and geomorphological parameters. This work aims at examining these relations in polygonal terrain. We analysed composition and cover of vascular plant taxa and surface height, active layer depth, soil temperature, carbon and nitrogen content, pH and electrical conductivity in four polygon mires located on the Yukon coast. We found that vascular plant species composition and cover correlates best with relative surface height. Ridges of low-centred polygons and raised centres of …
Опубликована Июль 29, 2016
Daily temperature measurements from six meteorological stations along the coast and fjords of western Spitsbergen have been digitized and quality controlled in a Norwegian, Russian and Polish collaboration. Complete daily data series have been reconstructed back to 1948 for all of the stations. One of the station’s monthly temperature series has previously been extended back to 1898 and is included in this study. The long-term series show large temperature variability on western Spitsbergen with colder periods in the 1910s and 1960s and warmer periods in the 1930s, 1950s and in the 21st century. The most recent years are the warmest …
Опубликована Окт. 9, 2017
Polar bears have experienced a rapid loss of sea-ice habitat in the Barents Sea. Monitoring this subpopulation focuses on the effects on polar bear demography. In August 2015, we conducted a survey in the Norwegian Arctic to estimate polar bear numbers and reveal population substructure. DNA profiles from biopsy samples and ear tags identified on photographs revealed that about half of the bears in Svalbard, compared to only 4.5% in the pack ice north of the archipelago, were recognized recaptures. The recaptured bears had originally been marked in Svalbard, mostly in spring. The existence of a local Svalbard stock, and …
Опубликована Апрель 10, 2017
Geological and geophysical studies undertaken during the Russian Arktika-2012 Expedition of 2012 produced evidence of basement outcrops on the steep slopes of the Mendeleev Rise seamounts. Observations of the outcrops from research submarines showed that part of the steep slopes interpreted as basement outcrops based on seismic data were overlain by a light sediment cover. The actual areas of the basement outcrops are therefore much less than indicated by the seismic data alone. The outcrops found are of 5–10 to 100–200 m and are often stretched along some hypsometric level or arranged obliquely, crossing a slope at an angle to …
Опубликована Июнь 30, 2017
Snow avalanches pose a threat to people and infrastructure in and around Svalbard’s main settlement Longyearbyen. Since January 2016, publically available regional avalanche warnings are issued daily for Nordenskiöld Land, the area around Longyearbyen. Avalanche warning services rely on information of when and where avalanches occur. Systematic field observations of avalanche activity are not feasible across all of the vast area (ca. 7200 km2) of Nordenskiöld Land. Svalbard also experiences over four months of polar night per year. However, using synthetic aperture radar (SAR), a weather- and light-independent technique, large areas can be monitored at once. We have developed a …
Опубликована Окт. 6, 2017
Ringed seals (Pusa hispida) are the most ice-associated of all Arctic pinnipeds. In the Svalbard area, this species has always given birth, moulted and rested on sea ice. In addition, much of their food has been comprised of ice-associated prey. Recently, ringed seals have been reported to be using terrestrial substrates as a haul-out platform in some fjords on the west coast of Spitsbergen. In many cases the seals involved are harbour seals (Phoca vitulina), which are extending their distribution into new areas within the Svalbard Archipelago and which are being misclassified as ringed seals. However, this study reports that …
Опубликована Апрель 25, 2017
Svalbard, a High-Arctic archipelago over which Norway practises sovereignty in accordance with the terms of the Svalbard Treaty, has become an increasingly important area for Arctic research and higher education. There are four more or less permanent settlements with substantial research infrastructure, and a few manned observatories for special purposes. Several Norwegian and foreign research institutions have established stations and installations in the archipelago. With coal mining activity scaling down because of economic difficulties and lack of political support for subsidies, Norwegian policy will prioritize research and higher education as a way of maintaining Norwegian settlements in Svalbard. I give …
Опубликована Июль 31, 2018
Relative abundances of 157 diatom taxa from Yakutian lake surface-sediments were investigated for their potential to indicate certain environmental conditions. Data from 206 sites from Arctic, sub-Arctic and boreal environments were included. Redundancy analyses were performed to assess the explanatory power of mean July temperature (T July ), conductivity, pH, dissolved silica concentration, phosphate concentration, lake depth and vegetation type on diatom species composition. Boosted regression tree analyses were performed to infer the most relevant environmental variables for abundances of individual taxa and weighted average regression was applied to infer their respective optimum and tolerance. Electrical conductivity was best indicated …
Опубликована Март 19, 2018
Permafrost thaw induced by climate change will cause increased release of nutrients and organic matter from the active layer to Arctic streams and, with increased water temperature, will potentially enhance algal biomass and nutrient uptake. Although essential for accurately predicting the response of Arctic streams to environmental change, knowledge of nutrient release on current Arctic in-stream processing is limited. Addressing this research gap, we quantified nutrient uptake of short-term releases of NO 3− , PO 43- and NH 4+ during peak snowmelt season in five streams of contrasting physiochemical characteristics (from unstable, highly turbid to highly stable, clear-water systems) in …