Western Scandinavia Research Articles

The Mesozoic of Western Scandinavia and East Greenland

Thick Mesozoic sediments are found offshore Norway and Denmark, and Mesozoic rocks are present and well exposed in Denmark, along the coast of East Greenland and on the arctic islands of Svalbard. During the Mesozoic, Scandinavia and Greenland were subject to major extension in the Late Permian-Early Triassic and Late Jurassic-Early Cretaceous, prior to Cenozoic opening of the North Atlantic. Deep basins developed along the rift zones of the North Sea and between East Greenland and Norway, and were filled with sediments derived from mainland Scandinavia and Greenland. The marginal areas bordering the rift zones suffered less subsidence, as did the epicontinental Barents Sea.

Beryllium-10 exposure ages of erratic boulders in southern Norway and implications for the history of the Fennoscandian Ice Sheet

The margins of the Fennoscandian Ice Sheet (FIS) during the Last Glacial Maximum (LGM) are fairly well constrained, yet the thickness of the FIS and its temporal evolution are poorly known. Here, we use beryllium-10 ( 10Be) exposure ages of glacially transported boulders along three vertical transects in southern Norway to determine past ice-sheet elevations. The ice surface elevation during the LGM at our westernmost site, Skåla, was likely at approximately 1440 m, coinciding with a previously mapped trimline. At our central site, Blåhø, the ice surface elevation at the LGM was at least at ∼1620 m, likely closer to 1800 m. At Elgåhogna, our easternmost site, LGM ice was above the summit elevation of 1460 m. Rapid deglaciation began at Skåla and Blåhø at approximately 13.5–14.5 10Be ka and at approximately 12 10Be ka at Elgåhogna. By approximately 9 10Be ka, the FIS had thinned to below our lowest sample at each location. Periods of rapid thinning correlate with an exposure dated ice-margin history, as well as the glaciation curve for western Scandinavia. Our data, when combined with previous bedrock and blockfield (highly weathered bedrock on summits) exposure ages, resolve a long-standing debate over the age and geomorphic interpretation of blockfields and weathering zones in southern Norway. Frozen-bed, low-erosive ice clearly covered the summit blockfields at Blåhø, and especially at Elgåhogna, where we find a large and progressive divergence between boulder and bedrock exposure ages with elevation. We conclude that the lower limit of blockfields in these areas should be interpreted as an englacial thermal boundary, rather than the upper limit of the LGM FIS, and that blockfields have survived multiple glacial cycles. We also compare our deglaciation record with several models of the FIS. Models that predict how the FIS changed during deglaciation, either through inversion of crustal rebound or through climate-dependent forward modeling, generally match our exposure ages reasonably well during deglaciation, but predict larger LGM surface elevations than our data indicate. On the other hand, the CLIMAP maximum model, which provides LGM elevations only, agrees with our results fairly well.

The ‘Little Ice Age’ glacial expansion in western Scandinavia: summer temperature or winter precipitation?

Reconstructing the temporal and spatial climate development on a seasonal basis during the last few centuries, including the ‘Little Ice Age’, may help us better understand modern-day interplay between natural and anthropogenic climate variability. The conventional view of the climate development during the last millennium has been that it followed a sequence of a Medieval Warm Period, a cool ‘Little Ice Age’ and a warming during the later part of the 19th century and in particular during the late 20th/early 21st centuries. However, recent research has challenged this rather simple sequence of climate development. Up to the present, it has been considered most likely that the ‘Little Ice Age’ glacial expansion in western Scandinavia was due to lower summer temperatures. Data presented here, however, indicate that the main cause of the early 18th century glacial advance in western Scandinavia was mild and humid winters associated with increased precipitation and high snowfall on the glaciers.

An evaluation of the role of hurricane Olga (2001) in an extreme rainy event in Israel using dynamic tropopause maps

During the period from end of November to early December 2001, a sequence of extremely intense synoptic developments occurred over the area from the Atlantic to Mediterranean. These included the formation of hurricane Olga, an intensification of the Icelandic Low, strengthening of the subtropical westerly jet stream (STJ) over North Africa, formation of the Red Sea Trough (RST) and Cyprus Low cyclones, which resulted in torrential rains in Israel on December 4–5. The evolution of the synoptic processes over a large area from the Atlantic to Western Europe and the Mediterranean region during November 25–December 2 is investigated here with the help of dynamic tropopause patterns calculated based on reanalysis data. It is shown that the chain of extreme weather events was triggered by the acceleration of a coherent tropopause disturbance (CTD) over the Labrador Sea. Two branches of the process may be distinguished, southern and northern. The southern one was associated with the transformation of a tropical storm into hurricane Olga, strengthening of the STJ and eventually the formation of the RST cyclone. The RST contributed to the intensification of the transport of moist air masses from equatorial Africa to the Mediterranean region. The northern branch was determined by an eastward drift of the CTD, moist air mass transport from the area of the hurricane to the North Atlantic and the European-Mediterranean region, strengthening of the Icelandic Low and formation of an upper troposphere potential vorticity-streamer system over western Scandinavia. Displacement of the streamer to the Mediterranean region and its interaction with the RST system played a major role in the development of the powerful Cyprus Low cyclone over the northeastern Mediterranean region.

A high-resolution reconstruction of Storglaciären mass balance back to 1780/81 using tree-ring data and circulation indices

Storglaciären in northernmost Sweden has the world's longest ongoing continuous mass-balance record, starting in 1946. To extend this mass-balance record, we have reconstructed summer ( b S) and winter ( b W) mass balances separately back to the mass balance year 1780/81 with annual resolution. We used tree-ring data for b S and a set of circulation indices, based on the sea-level pressure, for b W. Both proxies have correlation coefficients with respective mass balance components of ca. 0.7. The reconstructed net balance ( b N) of Storglaciären was well correlated to the observations during 1946–1980 ( r = 0.8, p < 0.05). Our reconstruction agrees well with previously obtained results of northern Sweden glacier variability, where the predominantly positive b N years between 1890 and 1910 correspond to the well documented post-Little Ice Age advance of Storglaciären. Furthermore, the results suggest that b S, as a function of summer temperatures, is more important than b W in determining the b N, which is contrary to glaciers in the maritime parts of western Scandinavia. In general, b N has been negative over the last 220 yr, suggesting a predomination of continental conditions over northern Sweden. However, the influence of b W increased in the late twentieth century, indicating a shift to a more oceanic climate regime.

Glacial/interglacial instabilities of the Western Boundary Under Current during the last 365 kyr from Sm/Nd ratios of the sedimentary clay-size fractions at ODP site 646 (Labrador Sea)

We present 40 Sm–Nd isotope measurements of the clay-size (< 2 μm) fractions of sediments from the Southern Greenland rise (ODP-646) that span the last 365 kyr. These data track changes in the relative supply of fine particles carried into the deep Labrador Sea by the Western Boundary Under Current (WBUC) back to the fourth glacial–interglacial cycles. Earlier studies revealed three general sources of particles to the core site: (i) Precambrian crustal material from Canada, Greenland, and/or Scandinavia ( North American Shield — NAS), (ii) Palaeozoic or younger crustal material from East Greenland, NW Europe, and/or western Scandinavia ( Young Crust — YC) and (iii) volcanic material from Iceland and the Mid-Atlantic Ridge (MAR). Clay-size fractions from glacial sediments have the lowest Nd isotopic ratios. Supplies of young crustal particles were similar during glacial oxygen isotope stages (OIS) 2, 6, and 10. In contrast the mean volcanic contributions decreased relative to old craton material from OIS 10 to OIS 6 and then from OIS 6 to OIS 2. The glacial OIS 8 interval displays a mean Sm/Nd ratio similar to those of interglacials OIS 1, 5, and 9. Compared with other interglacials, OIS 7 was marked by a higher YC contribution but a similar ∼ 30% MAR supply. The overall NAS contribution dropped by a factor of 2 during each glacial/interglacial transition, with the MAR contribution broadly replacing it during interglacials. To decipher between higher supplies and/or dilution, particle fluxes from each end member were estimated. Glacial NAS fluxes were systematically higher than interglacial fluxes. During the time interval examined, fine particle supplies to the Labrador Sea were strongly controlled by proximal ice-margin erosion and thus echoed the glacial stage intensity. In contrast, the WBUC-carried MAR supplies from the eastern basins did not change significantly throughout the last 365 kyr, except for a marked increase in surface-sediments that suggests unique modern conditions. Distal WBUC-controlled inputs from the Northern and NE North Atlantic seem to have been less variable than proximal supplies linked with glacial erosion rate.

Briksdalsbreen in western Norway: AD 1900-2004 frontal fluctuations as a combined effect of variations in winter precipitation and summer temperature

Mountain glaciers and ice caps are sensitive to changes in regional and global climate. Temporal glacier variations, manifested in change of volume, area and length, provide some of the clearest signals of climate change in nature. Therefore, glaciers are considered key indicators for the detection of global warming. Except for a few glaciers in western Scandinavia, glaciers in Europe are in retreat, following the global trend. Maritime (coastal) glaciers in western Norway experienced positive mass balance and large frontal advance during the 1990s because of increased winter accumulation. In contrast, after 1996, and especially since 2001, these glaciers have experienced strong negative mass balance and, as a result of short (&lt; 5 years) response time, frontal retreat. Briksdalsbreen, a short and steep outlet glacier from Jostedalsbreen (the largest glacier on mainland Europe), retreated 230 m between 1996/97 and 2004, with a maximum annual retreat of 130 m in 2003/2004. This is the largest annual retreat recorded since the start of the frontal measurements in 1900. This study demonstrates that glacier fluctuations are not only a response to ablation-season temperature variations, but are also highly dependent on accumulation-season precipitation. The records of glacier-front variations and the climate variability over the last-100 years in western Norway may be regarded as a ‘modern analogue’ for other Holocene events and are useful in evaluating the likelihood that similar climate and glacier variability will occur in the future.

The accretionary Svecofennian orogen—insight from the BABEL profiles

The BABEL profiles B, C, 1–7 form a 1200 km long nearly continuous cross-section through the Svecofennides. The near-vertical marine reflection profiles display a wide range of crustal structures that can be associated with both the accretionary Svecofennian orogeny (1.96–1.75 Ga) and the following Subjotnian and Jotnian rift-stages (1.65–1.11 Ga). The Svecofennian accretionary orogeny took place when a number of micro-plates with island arc affinities and surface expression of a large archipelago accreted to the continental Karelian plate. Some of the accreting terranes seem to have had older cores that have acted as crustal indentors during the collision. BABEL profiles 3 and 4 image a series of collisional terrane boundaries between Karelian continental margin, Savo arc (SA) and Central-Finland arc (CFA). In the north, the Karelian margin has been both over- and underthrust by the Savo arc. CFA comprises a folded thrust package on top of a continental nucleus and the Savo arc. The associated subduction zone and accretionary prism are interpreted to lie to the south, underneath the Bothnian basin area, where prominent NE-dipping, lower to middle crustal reflections are found along BABEL profiles 1 and 4. An oblique collision of the Central Finland arc and the continent resulted in the development of the strike-slip fault on the young, hot Savo arc. BABEL profiles 1, 6, 7 and C image the internal architecture of the Southern and Central Finland arcs. The unusually thick crust (55–60 km) hosts unreflective, high density, mafic intrusions acting as a crustal indentor. A highly reflective antiform structure developed on the southern side of it. Southern Finland arc complex (SFA) is an imbrication structure comprising stacked slices of arc-related crust on an older continental nucleus, Bergslagen nucleus. Prior to the collision, the SFA suffered from gravitational collapse during which the crust was thinned. Profile B images the architecture of the Central and Southern Swedish Svecofennides. The Sörmland terrane (SöB) is interpreted as the accretionary prism of the Southern Finland arc squeezed between the Svecofennian collage in the north and the advancing continent to the south. The southern continent/island arc is characterised by NE dipping crustal reflections and Moho offsets as well as step-wise increasing thickness of the crust. After the final collision, large volumes of mantle-derived material intruded the crust as large mushroom-shaped plutons. They are interpreted as the heat source for the TIB magmatism in southern and western Scandinavia.

The Longue Durée of Genetic Ancestry: Multiple Genetic Marker Systems and Celtic Origins on the Atlantic Facade of Europe

Celtic languages are now spoken only on the Atlantic facade of Europe, mainly in Britain and Ireland, but were spoken more widely in western and central Europe until the collapse of the Roman Empire in the first millennium a.d. It has been common to couple archaeological evidence for the expansion of Iron Age elites in central Europe with the dispersal of these languages and of Celtic ethnicity and to posit a central European "homeland" for the Celtic peoples. More recently, however, archaeologists have questioned this "migrationist" view of Celtic ethnogenesis. The proposition of a central European ancestry should be testable by examining the distribution of genetic markers; however, although Y-chromosome patterns in Atlantic Europe show little evidence of central European influence, there has hitherto been insufficient data to confirm this by use of mitochondrial DNA (mtDNA). Here, we present both new mtDNA data from Ireland and a novel analysis of a greatly enlarged European mtDNA database. We show that mtDNA lineages, when analyzed in sufficiently large numbers, display patterns significantly similar to a large fraction of both Y-chromosome and autosomal variation. These multiple genetic marker systems indicate a shared ancestry throughout the Atlantic zone, from northern Iberia to western Scandinavia, that dates back to the end of the last Ice Age.

Rapid and rhythmic ice sheet fluctuations in western Scandinavia 15-40 Kya?a review

Rapid and rhythmic ice sheet fluctuations in western Scandinavia 15-40 Kya?a review

Rapid and rhythmic ice sheet fluctuations in western Scandinavia 15-40 Kya–a review

The onshore record of Middle to Late Weichselian sediments and glacial history in Norway indicates a succession of four major ice advances alternating with rapid, considerable ice recessions and interstadial conditions. During all the glacial advances the ice sheet expanded from onshore/inland positions to the shelf areas. The basis for visualizing these variations in glaciation curves constructed along nine transects from inland to shelf, and for interpretation of the palaeoclimatic history, is the regional Quaternary stratigraphy, more than 300 datings, fossil content and some palaeomagnetic data. The methods applied in recent years for AMS radiocarbon dating of glacial sediments with low organic carbon content have given promising results with respect to accuracy and precision, and the results of such datings were an important tool for our reconstructions and for timing of the ice oscillations. The rapid and rhythmic ice fluctuations, as reconstructed in our new model, have been fairly synchronous in most parts of Norway. Ice advances commenced and culminated at 40, 30-28, 24-21 and 18-15 (14C) Kya. We describe three intervening interstadials from inland sites: Hattfjelldal I, Hattfjelldal II and Trofors. Our stratigraphical record also includes many indications of high, pre-Holocene, relative sea levels, suggesting a considerable glacioisostatic depression of western Scandinavia during the interstadials. In our glaciation model we suggest that, in addition to precipitation, the mountainous fjord and valley topography, glacial isostasy and relative sea level changes were probably more important for the size of the glacial fluctuations than were air temperature changes.

The European Origin of the Finns and their Relation to the Indo-Europeans

The author traces the history of the prevailing hypothesis which assumes that the ancestors of the present-day Finns and Estonians migrated into their contemporary north European homeland as recently as two thousand years ago. Instead, he suggests that during the latter part of the Wurm glaciation, more than ten thousand years ago, when northern Europe was still covered by ice, they and the Saami (Suomi) were hunters and fishers who occupied an area between the Danube and the Ukraine. They subsequently followed the retreating ice northwards into the eastern Baltic, as that area became habitable. His theory, which is regarded as controversial, would see Finno-Ugrian speakers inhabiting northern Europe before Indo-European speaking farmers displaced them in Northern Germany and western Scandinavia.

Wintertime variability of Mediterranean precipitation and its links with large-scale circulation anomalies

A standard principal component analysis has been performed over the Mediterranean and over the larger European region on monthly precipitation anomalies for the winters between 1979 and 1995. The main centres of action of the associated EOFs are very similar for the two regions and the two sets of PCs are highly correlated with each other. Focusing on the Mediterranean region, the same analysis has been performed using 500 hPa geopotential height monthly anomalies taken from the operational NCEP analysis. Comparing the two sets of PCs associated with upper-air and surface data, a strong correlation has been found suggesting the presence of a two-way link between regional precipitation patterns and large-scale circulation anomalies. For both fields, the largest fraction of variance is explained by the North Atlantic Oscillation, while smaller but still substantial fractions are explained by other known patterns of large-scale variability such as the Eastern Atlantic pattern and the Euro-Atlantic blocking. No detectable connection has been found between Mediterranean precipitation patterns and El Nino SST anomalies during winter. With respect to temporal variability, significant trends have been found over most European areas during the winters considered. The associated pattern is characterised by a substantial increase of precipitation over western Scandinavia and a general decrease over southern Europe. This result is confirmed by analysing data from stations located in northern Italy.

Alpine Evidence for Atmospheric Circulation Patterns in Europe during the Last Glacial Maximum

The configuration of Alpine accumulation areas during the last glacial maximum (LGM) has been reconstructed using glacial–geological mapping. The results indicate that the LGM ice surface consisted of at least three major ice domes, all located south of the principal weather divide of the Alps. This implies that the buildup of the main Alpine ice cover during oxygen isotope stage (OIS) 2 was related to precipitation by dominant southerly atmospheric circulation, in contrast to today's prevalent westerly airflow. Such a reorganization of the atmospheric circulation is consistent with a southward displacement of the Oceanic Polar Front in the North Atlantic and of the associated storm track to the south of the Alps. These results, combined with additional paleoclimate records from western and southern Europe, allow an interpretation of the asynchronous evolution of the different European ice caps during the last glaciation. δ18O stages (OIS) 4 and 3 were characterized by location of the Polar Front north of 46°N (Gulf of Biscay). This affected prevailing westerly circulation and, thus, ice buildup in western Scandinavia, the Pyrénées, Vosges, and northern Alps. At the LGM, however, the Polar Front lay at ∼44°N, causing dominating southerly circulation and reduced precipitation in central and northern Europe.

The effect of temperature on site index in western Canada and Scandinavia estimated from IUFRO Pinus contorta provenance experiments

Site index was calculated for 78 experimental plantations in western Canada and northern Finland and Sweden, representing a wide range of site environments where lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) is considered as a potential afforestation species. The plantations and provenances belong to the International Union of Forest Research Organizations' international provenance testing program, and estimates of site index (projected 50-year height) were based on height growth of recommended provenances. The estimated site indices were used in regression analyses with temperature data and estimated soil fertilities to predict the change in forest production due to a warmer climate, which may follow an expected rise in atmospheric CO2. The influence of temperature was strong and considerably stronger in northern Finland and Sweden than in Canada. The relationships differed between the two continents and between sites located north of 56°N and south of that latitude. Soil fertility had a small but significant influence. Estimates of increases in site index and potential productivity in different scenarios for increases in temperature sum and average July temperatures are given.

Is the North Atlantic Oscillation reflected in Scandinavian glacier mass balance records?

The North Atlantic Oscillation (NAO) is one of the modes of climate variability in the North Atlantic region. The atmospheric circulation during the winter season in this region commonly displays a strong meridional (north-south) pressure contrast, with low air pressure (cyclone) centred close to Iceland and high air pressure (anticyclone) near the Azores. This pressure gradient drives the mean surface winds and the mid-latitude winter storms from west to east across the North Atlantic, bringing mild moist air to northwest Europe. The NAO index is based on the difference of normalised sea-level pressures (SLP) between Ponta Delgada, Azores and Stykkisholmur, Iceland. The SLP anomalies at these stations are normalised by division of each monthly pressure by the long-term (1865-1984) standard deviation. Interannual atmospheric climate variability in northwest Europe, especially over Great Britain and western Scandinavia has, during the last decades, been attributed mainly to the NAO, causing variations in the winter weather over the northeast North Atlantic and the adjacent land areas. A comparison between the NAO index and the winter (December-March) precipitation between ad 1864 and 1995 in western Norway shows that these are strongly linked (correlation coefficient 0.77). Variations in the NAO index are also reflected in the mass balance records of glaciers in western Scandinavia. The NAO index is best correlated with mass balance data from maritime glaciers in southern Norway (e.g. Alfotbreen R 2 ! 0.51). The record of Holocene (last ca. 11 500 cal. yr) glacier variations of maritime glaciers in western Scandinavia is thus a proxy of pre-instrumental NAO variations. Copyright  2000 John Wiley & Sons, Ltd.

The effect of temperature on site index in western Canada and Scandinavia estimated from IUFRO &lt;i&gt;Pinus contorta&lt;/i&gt; provenance experiments

Site index was calculated for 78 experimental plantations in western Canada and northern Finland and Swe- den, representing a wide range of site environments where lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) is considered as a potential afforestation species. The plantations and provenances belong to the International Union of Forest Research Organizations' international provenance testing program, and estimates of site index (pro - jected 50-year height) were based on height growth of recommended provenances. The estimated site indices were used in regression analyses with temperature data and estimated soil fertilities to predict the change in forest production due to a warmer climate, which may follow an expected rise in atmospheric CO2. The influence of temperature was strong and considerably stronger in northern Finland and Sweden than in Canada. The relationships differed between the two continents and between sites located north of 56°N and south of that latitude. Soil fertility had a small but significant influence. Estimates of increases in site index and potential productivity in different scenarios for increases in tempera - ture sum and average July temperatures are given.

Detailed mapping of the phosphomannomutase 2 (PMM2) gene and mutation detection enable improved analysis for Scandinavian CDG type I families.

The gene for carbohydrate-deficient glycoprotein syndrome type I (CDG1) has previously been localised by us close to marker D16S406 in chromosome region 16p13.2-3. We also presented data indicating a strong founder mutation associated with a specific haplotype in CDG I patients from western Scandinavia. The phosphomannomutase 2 (PMM2) gene was recently put forward as a likely CDG1 candidate gene. We have now shown that the specific haplotype is associated with the PMM2 mutation 357C > A. Using data from radiation hybrid panel we have refined the position of the PMM2 gene to very close to marker D16S3020 in the interval between D16S406 and AFM282ze1 on the distal side and D16S3087 on the proximal side. Due to the severity of the disease many families request prenatal diagnostic services for CDG I. In the meantime, until the mutation spectrum is fully examined, we propose the combined use of mutation analysis and linkage analysis with polymorphic markers as diagnostic tools for Scandinavian CDG I families requesting prenatal diagnosis. Using this strategy we have to date successfully performed 15 prenatal diagnoses for CDG I.

UK international equity joint ventures in technology and innovation: an analysis of patterns of activity and distribution

This paper presents a series of data examining the pattern of activity of the UK, in terms of equity joint ventures (EJV) formation, with partners in Western Europe, Scandinavia, USA and Japan and within technological industries. The data set consists of 1,415 equity joint ventures (EJVs) formed between 1945‐1989. The pattern of activity is examined over time, in terms of industry and geographical distribution. The data presented also include information concerning domestic EJV formation for each of the countries studied which previous research has not considered. The paper also comments on the need to focus on “soft” vs “hard” issues in examining the context and performance outcomes of international strategic alliances and equity joint ventures (EJVs) and avenues for future research.

Changes in the thermal growing season in Nordic countries during the past century and prospects for the future

The start, end, duration and intensity of the thermal growing season (the period with mean daily temperatures exceeding 5°C) during the past century (1890-1995) was analysed at nine sites in the Nordic region. Statistical comparisons were made between three adjacent 35-year periods. The results indicate that the growing season lengthened considerably at all sites between 1891-1925 and 1926-1960. Lengthening has continued at a slower rate up to the present at the eight Fennoscandian sites but not at the Icelandic site. In contrast, the intensity of the growing season, expressed by effective temperature sum above 5°C, which increased at all sites between the first two periods, has decreased slightly at all locations except Turku in recent decades. Under three scenarios, representing the range of estimated greenhouse gas-induced warming by the 2050s, the growing season is expected to lengthen at all sites. For a “Central” scenario, the greatest lengthening is computed for southern and western Scandinavia (7-8 weeks) with smaller changes in Finland (4 weeks) and Iceland (3 weeks). With a lengthening growing season during the past century in Fennoscandia, there are likely to have been impacts on natural and managed ecosystems. Some evidence of recent biotic and abiotic effects already exists, but other indicators of long-term change remain to be analysed.