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Svalbard and Jan Mayen, Norway

Ingolfsson T.,University of Iceland | Ingolfsson T.,University Center in Svalbard | Landvik J.Y.,Norwegian University of Life Sciences
Quaternary Science Reviews | Year: 2013

The history of research on the Late Quaternary Svalbard-Barents Sea ice sheet mirrors the developments of ideas and the shifts of paradigms in glacial theory over the past 150 years. Since the onset of scientific research there in the early 19th Century, Svalbard has been a natural laboratory where ideas and concepts have been tested, and played an important (but rarely acknowledged) role in the break-through of the Ice Age theory in the 1870's. The history of how the scientific perception of the Svalbard-Barents sea ice sheet developed in the mid-20th Century also tells a story of how a combination of fairly scattered and often contradictory observational data, and through both deductive and inductive reasoning, could outline a major ice sheet that had left but few tangible fingerprints. Since the 1980's, with increased terrestrial stratigraphical data, ever more marine geological evidence and better chronological control of glacial events, our perception of the Svalbard-Barents Sea ice sheet has changed. The first reconstructions depicted it as a static, concentric, single-domed ice sheet, with ice flowing from an ice divide over the central northern Barents Sea that expanded and declined in response to large-scale, Late Quaternary climate fluctuations, and which was more or less in tune with other major Northern Hemisphere ice sheets. We now increasingly perceive it as a very dynamic, multidomed ice sheet, controlled by climate fluctuations, relative sea-level change, as well as subglacial topography, substrate properties and basal temperature. In this respect, the Svalbard-Barents Sea ice sheet will increasingly hold the key for understanding the dynamics and processes of how marine-based ice sheets build-up and decay. © 2012 Elsevier Ltd. Source

Coulson S.J.,University Center in Svalbard
Canadian Entomologist | Year: 2013

The High Arctic represents a unique environment, an environment from where knowledge is limited and which is currently experiencing rapid change. The archipelago of Svalbard in the European High Arctic possesses a terrestrial and freshwater invertebrate fauna that is distinctive and diverse. However, the majority of studies concentrate on the fauna of the comparatively mild west coast. Very few investigations of the colder east coast exist. Furthermore, scientific investigations are relatively recent. Scientific records of the terrestrial invertebrate fauna begin in the mid-19th century with species inventories and community descriptions but experimental field-based studies and physiological investigations did not commence until the 1980s. Some 570 articles consider this fauna, 54% of which have appeared since 1990. There is hence a dramatic and rapid increase in our understanding, which is not only improving our comprehension of Arctic ecosystem functioning but also providing a baseline for environmental change studies. Due to a largely pristine environment, a political focus and relative ease of logistics, Svalbard is set to become a focus of such studies. This article considers the state of knowledge of the terrestrial and freshwater invertebrate fauna of Svalbard, current research, and discusses the threats to the distinctive communities. Copyright © 2013 Entomological Society of Canada. Source

Romanovsky V.E.,University of Alaska Fairbanks | Smith S.L.,Geological Survey of Canada | Christiansen H.H.,University Center in Svalbard
Permafrost and Periglacial Processes | Year: 2010

The permafrost monitoring network in the polar regions of the Northern Hemisphere was enhanced during the International Polar Year (IPY), and new information on permafrost thermal state was collected for regions where there was little available. This augmented monitoring network is an important legacy of the IPY, as is the updated baseline of current permafrost conditions against which future changes may be measured. Within the Northern Hemisphere polar region, ground temperatures are currently being measured in about 575 boreholes in North America, the Nordic region and Russia. These show that in the discontinuous permafrost zone, permafrost temperatures fall within a narrow range, with the mean annual ground temperature (MAGT) at most sites being higher than -2°C. A greater range in MAGT is present within the continuous permafrost zone, from above -1°C at some locations to as low as -15°C. The latest results indicate that the permafrost warming which started two to three decades ago has generally continued into the IPY period. Warming rates are much smaller for permafrost already at temperatures close to 0°C compared with colder permafrost, especially for ice-rich permafrost where latent heat effects dominate the ground thermal regime. Colder permafrost sites are warming more rapidly. This improved knowledge about the permafrost thermal state and its dynamics is important for multidisciplinary polar research, but also for many of the 4 million people living in the Arctic. In particular, this knowledge is required for designing effective adaptation strategies for the local communities under warmer climatic conditions. © 2010 John Wiley & Sons, Ltd. Source

Delmas L.,University Center in Svalbard
Journal of Glaciology | Year: 2013

Three spontaneous avalanches were observed in Lia, Longyearbyen, Svalbard, each occurring naturally under similar temperature conditions. Automatic measurements of temperature inside the snowpack led to examination of the triggering of avalanches in cold conditions following a rapid drop in temperature. The mechanical properties of ice depend on the slab temperature and I ask: could a rapid temperature change affect the mechanical properties differently considering a slab consisting of (1) rounded grains or (2) faceted grains? Snow is considered as a foam of ice crystals, and triaxial deformation tests are performed at constant strain rate to examine the influence of temperature and grain type on the mechanical properties. Although the snow densities in the two sample sets were almost identical, some differences due to grain type were observed. In particular, the set with faceted grain snow started to flow at higher stresses than the set with rounded grains. Source

Redfield T.F.,Geological Survey of Norway | Osmundsen P.T.,Geological Survey of Norway | Osmundsen P.T.,University Center in Svalbard
Bulletin of the Geological Society of America | Year: 2013

We present data that link Scandinavia's passive-margin domains under a unified system invoking isostatically driven, postextension phase vertical adjustments to severe crustal thinning. Topographic and geological data indicate that the relative location of the first landward occurrence of total crustal embrittlement or deformation coupling- the Taper Break-controlled and continues to control Scandinavia's post-thinning geomorphic evolution. Formed during Late Jurassic or Early Cretaceous thinning, yet marked today by seismicity, the Taper Break closely approximates the boundary between(1) less-stretched lithosphere that increases in rigidity both toward land and through postrifttime, and (2) the highlyattenuated, pervasively faulted, permanently weakened lithosphere of the distal margin. Following the stretching, thinning, and exhumation phases proposed by other workers, an accommodation phase is warranted. Commencing during quot;sagquot; basin time and continuing today, it is probably driven by thermal cooling and mass transfer from the escarpment to the basins offshore. The accommodation phase does not entirely coincide with the traditional postriftphase as the former may contain the latter. During accommodation, the original synriftescarpments can be eroded to very low base levels. Sharply tapered margin segments can undergo subsequent rejuvenation by out-of-sequence normal faulting and footwall uplift, probablyin response to tensile bending stresses engendered by lithosphericscale fl exure. Accommodation-phase upliftat passive margins is the inexorable and penultimate phase of hyperextension, and may perhaps be followed by the onset of subduction localized by the weakened lithosphere of the distal margin and the ocean-continent transition. © 2013 Geological Society of America. Source

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