Scandinavian Mountains
The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The western sides of the mountains drop precipitously into the North Sea and Norwegian Sea, forming the fjords of Norway, whereas to the northeast they gradually curve towards Finland. To the north they form the border between Norway and Sweden, reaching high at the Arctic Circle. The mountain range just touches northwesternmost Finland but are scarcely more than hills at their northernmost extension at the North Cape.
The mountains are relatively high for a range so young and are very steep in places; Galdhøpiggen in South Norway is the highest peak in mainland Northern Europe, at ; Kebnekaise is the highest peak on the Swedish side, at, whereas the slope of Halti is the highest point in Finland, at, although the peak of Halti is situated in Norway.
The Scandinavian montane birch forest and grasslands terrestrial ecoregion is closely associated with the mountain range.
Names in Scandinavia
In Swedish, the mountain range is called Skandinaviska fjällkedjan, Skanderna, Fjällen or Kölen. In Norwegian, it is called Den skandinaviske fjellkjede, Fjellet, Skandesfjellene, Kjølen or Nordryggen. The names Kölen and Kjølen are often preferentially used for the northern part, where the mountains form a narrow range near the border region of Norway and Sweden. In South Norway, there is a broad scatter of mountain regions with individual names, such as Dovrefjell, Hardangervidda, Jotunheimen, and Rondane.Orography
The mountain chain's highest summits are mostly concentrated in an area of mean altitude of over,) between Stavanger and Trondheim in South Norway, with numerous peaks over and some peaks over. Around Trondheim Fjord, peaks decrease in altitude to about, rising again to heights in excess of further north in Swedish Lapland and nearby areas of Norway. The southern part of the mountain range contains the highest mountain of Northern Europe, Galdhøpiggen at almost. This part of the mountain chain is also broader and contains a series of plateaux and gently undulating surfaces that hosts scattered inselbergs. The plateaux and undulating surfaces of the southern Scandinavian Mountains form a series of stepped surfaces. Geomorphologist Karna Lidmar-Bergström and co-workers recognize five widespread stepped surfaces. In eastern Norway, some of the stepped surfaces merge into a single surface. Dovrefjell and Jotunheimen are rises from the highest of the stepped surfaces. In south-western Norway, the plateaux and gently undulating surfaces are strongly dissected by fjords and valleys. The mountain chain is present in Sweden from northern Dalarna northwards; south of this point the Scandinavian Mountains lie completely within Norway. Most of the Scandinavian Mountains lack "alpine topography", and where present it does not relate to altitude. An example of this is the distribution of cirques in southern Norway that can be found both near sea level and at. Most cirques are found between.To the east, the Scandinavian Mountains proper bound with mountains that are lower and less dissected and are known in Swedish as the förfjäll. Generally the förfjäll do not surpass above sea level. As a geomorphic unit the förfjäll extends across Sweden as a long and broad belt from Dalarna in the south to Norrbotten in the north. While lower than the Scandinavian Mountains proper, the förfjäll
Climate, permafrost and glaciers
The climate of the Nordic countries is maritime along the coast of Norway, and much more continental in Sweden in the rain shadow of the Scandinavian Mountains. The combination of a northerly location and moisture from the North Atlantic Ocean has caused the formation of many ice fields and glaciers. In the mountains, the air temperature decreases with increasing altitude, and patches of mountain permafrost in regions with a mean annual air temperature of will be found at wind exposed sites with little snow cover during winter. Higher up, widespread permafrost may be expected at altitudes with a MAAT of, continuous permafrost at altitudes with a MAAT of.Within the EU-sponsored project PACE, a deep borehole was drilled in bedrock above Tarfala research station at an altitude of above sea level. The stable ground temperature at a depth of is still. The measured geothermal gradient in the drillhole of 1.17 °C /100 m allows to extrapolate a permafrost thickness of, a further proof that continuous permafrost exists in these altitudes and above, up to the top of Kebnekaise.
In the Scandinavian Mountains, the lower limit of widespread discontinuous permafrost drops from in the west of southern Norway to near the border with Sweden, and from in northern Norway to in northern, more continental Sweden. In contrast to the lower limit of permafrost, the mean glacier altitude is related to the amount of precipitation. Thus the snow line, or glacier equilibrium line as the limit between the accumulation zone and ablation zone shows the opposite trend, from in the west to in the east.
Geology
Bedrock
Most of the rocks of the Scandinavian Mountains are Caledonian, which means they were put in place by the Caledonian orogeny. Caledonian rocks overlie rocks of the much older Svecokarelian and Sveconorwegian provinces. The Caledonian rocks actually form large nappes that have been thrust over the older rocks. Much of the Caledonian rocks have been eroded since they were put in place, meaning that they were once thicker and more contiguous. It is also implied from the erosion that the nappes of Caledonian rock once reached further east than they do today. The erosion has left remaining massifs of Caledonian rocks and windows of Precambrian rock.While there are some disagreements, geologists generally recognize four units among the nappes: an uppermost, an upper, a middle and a lower unit. The lower unit is made up Ediacaran, Cambrian, Ordovician and Silurian-aged sedimentary rocks. Pieces of Precambrian shield rocks are in some places also incorporated into the lower nappes.
It was during the Silurian and Devonian periods that the Caledonian nappes were stacked upon the older rocks and upon themselves. This occurred in connection with the closure of the Iapetus Ocean as the ancient continents of Laurentia and Baltica collided. This collision produced a Himalayan-sized mountain range named the Caledonian Mountains roughly over the same area as the present-day Scandinavian Mountains. The Caledonian Mountains began a post-orogenic collapse in the Devonian, implying tectonic extension and subsidence. Despite occurring in about the same area, the ancient Caledonian Mountains and the modern Scandinavian Mountains are unrelated.
Origin
The origin of today's mountain topography is debated by geologists. Geologically, the Scandinavian Mountains are an elevated, passive continental margin similar to the mountains and plateaux found on the opposite side of the North Atlantic in Eastern Greenland or in Australia's Great Dividing Range. The Scandinavian Mountains attained their height by tectonic processes different from orogeny, chiefly in the Cenozoic. A two-stage model of uplift has been proposed for the Scandinavian Mountains in South Norway. A first stage in the Mesozoic and a second stage starting from the Oligocene. The uplift of South Norway has elevated the westernmost extension of the sub-Cambrian peneplain which forms part of what is known as the Paleic surface in Norway. In South Norway, the Scandinavian Mountains had their main uplift phase later than in northern Scandinavia which had its main phase of uplift in the Paleogene. For example, the Hardangervidda uplifted from sea level to its present in Early Pliocene times.The various episodes of uplift of the Scandinavian Mountains were similar in orientation and tilted land surfaces to the east while allowing rivers to incise the landscape. Some of the tilted surfaces constitute the Muddus plains landscape of northern Sweden. The progressive tilt contributed to create the parallel drainage pattern of northern Sweden. Uplift is thought to have been accommodated by coast-parallel normal faults and not by fault-less doming. Therefore, the common labelling of the southern Scandinavian Mountains and the northern Scandinavian Mountains as two domes is misleading. There are divided opinions on the relation between the coastal plains of Norway, the strandflat, and the uplift of the mountains.
Unlike orogenic mountains, there is no widely accepted geophysical model to explain elevated passive continental margins such as the Scandinavian Mountains. Various mechanisms of uplift have, however, been proposed over the years. A 2012 study argues that the Scandinavian Mountains and other elevated passive continental margins most likely share the same mechanism of uplift and that this mechanism is related to far-field stresses in Earth's lithosphere. The Scandinavian Mountains can according to this view be likened to a giant anticlinal lithospheric fold. Folding could have been caused by horizontal compression acting on a thin to thick crust transition zone.
Alternative lines of research have stressed the role of climate in inducing erosion that induces an isostatic compensation; fluvial and glacial erosion and incision during the Quaternary is thought to have contributed to the uplift of the mountain by forcing an isostatic response. The total amount of uplift produced by this mechanism could be as much as. Other geoscientists have implied diapirism in the asthenosphere as being the cause of uplift. One hypothesis states that the early uplift of the Scandinavian Mountains could be indebted to changes in the density of the lithosphere and asthenosphere caused by the Iceland plume when Greenland and Scandinavia rifted apart about 53 million years ago.