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 2,000 metres (6,600 ft) 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 (Nordkapp).
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 2,469 metres (8,100 ft);
Kebnekaise is the highest peak on the Swedish side, at 2,104 m (6,903 ft), whereas the slope of
Halti is the highest point in Finland, at 1,324 m (4,344 ft), although the peak of Halti is situated in Norway.
Its names in the Scandinavian languages are, in
SwedishSkandinaviska fjällkedjan, Skanderna (encyclopedic and professional usage), Fjällen ('the
Fells', common in colloquial speech) or Kölen ('the Keel'), and in
NorwegianDen skandinaviske fjellkjede, Fjellet, Skandesfjellene, Kjølen ('the Keel') or Nordryggen ('the North Ridge', name coined in 2013). 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.[3][4][5][6]
Orography
The mountain chain's highest summits are mostly concentrated in an area (of
mean altitude of over 1,000 m[7]) between
Stavanger and
Trondheim in South Norway, with numerous peaks over 1,300 m and some peaks over 2,000 m.[8] Around
Trondheim Fjord, peaks decrease in altitude to about 400–500 m rising again to heights in excess of 1,900 m further north in
Swedish Lapland and nearby areas of Norway.[8][A] The southern part of the mountain range contains the highest mountain of Northern Europe,
Galdhøpiggen at almost 2,500 m.[10] This part of the mountain chain is also broader and contains a series of
plateaux and gently undulating surfaces[8][11] that hosts scattered
inselbergs.[11] 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.
Dovre and
Jotunheimen are rises from the highest of the stepped surfaces.[12] In south-western Norway, the plateaux and gently undulating surfaces are strongly
dissected by
fjords and
valleys.[13] The mountain chain is present in Sweden from northern
Dalarna northwards; south of this point the Scandinavian Mountains lie completely within Norway.[8] Most of the Scandinavian Mountains lack "alpine topography",[B] and where present it does not relate to altitude.[11] An example of this is the distribution of
cirques in southern Norway that can be found both near sea level and at 2,000 m. Most cirques are found between 1,000 and 1,500 m.[15]
To the east, the Scandinavian Mountains proper bounds with mountains that are lower and less dissected and are known in Swedish as the förfjäll (literally 'fore-fell'). Generally the förfjäll do not surpass 1,000 m above sea level. As a geomorphic unit the förfjäll extends across Sweden as a 650 km long and 40 to 80 km broad belt from Dalarna in the south to
Norrbotten in the north. While lower than the Scandinavian Mountains proper, the förfjäll's pronounced
relief, its large number of plateaux, and its coherent valley system distinguish it from so-called undulating hilly terrain (Swedish: bergkullsterräng) and plains with residual hills (Swedish: bergkullslätt) found further east.[17]
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 (MAAT) of -1.5 °C 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 -3.5 °C, continuous permafrost at altitudes with a MAAT of -6.0 °C.[18]
Within the EU-sponsored project PACE (Permafrost and Climate in Europe), a 100 m deep borehole was drilled in bedrock above
Tarfala research station at an altitude of 1540 m above sea level. The stable ground temperature at a depth of 100 meters is still -2.75 °C.[19] The measured
geothermal gradient in the drillhole of 1.17 °C /100 m allows to extrapolate a permafrost thickness of 330 meters, 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 1700 meters in the west of southern Norway to 1500 meters near the border with Sweden, and from 1600 m in northern Norway to 1100 m in northern, more continental Sweden (
Kebnekaise area).[20] In contrast to the lower limit of permafrost, the mean glacier altitude (or glaciation limit) 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 1500 meters in the west (
Jostefonn) to 2100 meters in the east (
Jotunheimen).
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
Sveconorwegianprovinces. The Caledonian rocks actually form large
nappes (
Swedish: skollor) 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.[21]
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 (
Vendian),
Cambrian,
Ordovician and
Silurian-aged
sedimentary rocks. Pieces of Precambrian
shield rocks are in some places also incorporated into the lower nappes.[21]
It was during the Silurian and
Devonianperiods that the Caledonian nappes were stacked upon the older rocks and upon themselves. This occurred in connection to the
closure of the
Iapetus Ocean as the ancient continents of
Laurentia and
Balticacollided.[21] This collision produced a
Himalayas-sized mountain range named the
Caledonian Mountains roughly over the same area as the present-day Scandinavian Mountains.[22][23] The Caledonian Mountains began a
post-orogenic collapse in the Devonian, implying
tectonic extension and subsidence.[24] Despite occurring in about the same area, the ancient Caledonian Mountains and the modern Scandinavian Mountains are unrelated.[C]
The origin of today's mountain topography is debated by geologists.[27] 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.[23] The Scandinavian Mountains attained its height by tectonic processes different from orogeny, chiefly in the
Cenozoic.[26] 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.[22] 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[D] in Norway.[29][30] In South Norway, the Scandinavian Mountains had their main uplift phase later (
Neogene) than in northern Scandinavia which had its main phase of uplift in the
Paleogene.[31] For example, the
Hardangervidda uplifted from sea level to its present 1200–1100 m in
Early Pliocene times.[32]
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.[33] Some of the tilted surfaces constitute the
Muddus plains landscape of
northern Sweden.[31] The progressive tilt contributed to create the parallel
drainage pattern of northern Sweden.[33] Uplift is thought to have been accommodated by coast-parallel
normal faults and not by fault-less
doming.[33][34] Therefore, the common labelling of the southern Scandinavian Mountains and the northern Scandinavian Mountains as two domes is misleading.[33] There are divided opinions on the relation between the coastal plains of Norway, the
strandflat, and the uplift of the mountains.[E]
Unlike
orogenic mountains, there is no widely accepted
geophysical model to explain elevated passive continental margins such as the Scandinavian Mountains.[40] 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 (as are all passive margins).[41][42]
Alternative lines of research have stressed the
role of climate in inducing erosion that
induces an isostatic compensation;[25] 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.[25][27] The total amount of uplift produced by this mechanism could be as much as 500 m.[27] Other geoscientists have implied
diapirism in the
asthenosphere as being the cause of uplift.[25] 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.[43]
Many slopes and valleys are straight because they follow tectonic
fractures that are more prone to erosion.[13] Another result of tectonics in the relief is that slopes corresponding to
footwalls of
normal faults tend to be straight.[11]
There is evidence that the
drainage divide between the
Norwegian Sea and the south-east flowing rivers were once further west.[13] Glacial erosion is thought to have contributed to the shift of the divide, which in some cases ought to have been in excess of 50 km.[13] Much of the Scandinavian Mountains has been sculpted by
glacial erosion. The mountain chain is dotted with glacial
cirques usually separated from each other by
pre-glacialpaleosurfaces.[8] Glacier erosion has been limited in these paleosurfaces which form usually plateaus between valleys. As such the paleosurfaces were subject of diverging and slow ice flow during the glaciations. In contrast valleys concentrated ice flow forming fast glaciers or
ice streams.[15] At some locations coalesced cirques form
arêtes and
pyramidal peaks. Glacial reshaping of valleys is more marked in the western part of the mountain chain where drowned glacier-shaped valleys constitute the fjords of Norway. In the eastern part of the mountain chain, glacial reshaping of valleys is weaker.[8] Many mountain tops contain
blockfields which escaped glacial erosion either by having been
nunataks in the glacial periods or by being protected from erosion under
cold-based glacier ice.[13]Karst systems, with their characteristic
caves and
sinkholes, occur at various places in the Scandinavian Mountains, but are more common in the northern parts. Present-day karst systems might have long histories dating back to the Pleistocene or even earlier.[13]
Much of the mountain range is mantled by deposits of glacial origin including
till blankets,
moraines,
drumlins and glaciofluvial material in the form of
outwash plains and
eskers. Bare rock surfaces are more common in the western side of the mountain range. Although the ages of these deposits and landforms vary, most of them were formed in connection to the
Weichselian glaciation and the subsequent
deglaciation.[13]
The
Cenozoic glaciations that affected
Fennoscandia most likely began in the Scandinavian Mountains.[44] It is estimated that during 50% of the last 2.75 million years the Scandinavian Mountains hosted mountain-centered
ice caps and
ice fields.[45] The ice fields from which the
Fennoscandian Ice Sheet grew out multiple times most likely resembled today's ice fields in
AndeanPatagonia.[44][F] During the
last glacial maximum (ca. 20
kaBP) all the Scandinavian Mountains were covered by the Fennoscandian Ice Sheet, which extended well beyond the mountains into Denmark, Germany, Poland and the
former USSR. As the ice margin started to recede 22–17 ka BP the ice sheet became increasingly concentrated in the Scandinavian Mountains. Recession of the ice margin led the ice sheet to be concentrated in two parts of the Scandinavian Mountains, one part in South Norway and another in northern Sweden and Norway. These two centres were for a time linked, so that the linkage constituted a major drainage barrier that formed various large ephemeral
ice-dammed lakes. About 10 ka BP, the linkage had disappeared and so did the southern centre of the ice sheet a thousand years later. The northern centre remained a few hundred years more, and by 9,7 ka BP the eastern
Sarek Mountains hosted the last remnant of the Fennoscandian Ice Sheet.[46] As the ice sheet retreated to the Scandinavian Mountains it was dissimilar to the early mountain glaciation that gave origin to the ice sheet as the
ice divide lagged behind as the ice mass concentrated in the west.[44]
Of the 10 highest mountain peaks in Scandinavia (
prominence greater than 30 m or 98 ft), six are situated in
Oppland, Norway. The other four are situated in
Sogn og Fjordane, Norway.
There are 12 peaks in
Sweden that reach above 2,000 m high (6,600 ft), or 13 depending on how the peaks are defined. Eight of them are located in
Sarek National Park and the neighbouring national park
Stora Sjöfallet. The other four peaks are located in the further north region of
Kebnekaise. All mountain names are in
Sami but with the more common Swedish spelling of it.
2,104 m (6,903 ft)
Kebnekaise (
Lappland) – Note: Altitude includes the peak glacier. If melting continues, Kebnekaise Nordtoppen, just 500 meters away and 7 meters lower, might become the highest point.
2,097 m (6,880 ft)
Kebnekaise Nordtoppen (Lappland) – the highest fixed point in Sweden.
^The two high areas, north and south of
Trondheim, have been usually referred to as "domes" but technically they are not geological
domes.[9]
^A topography classification study found that 13.6% of the area of southern Norway has a proper "alpine relief", and that this is mostly concentrated in the fjord region of southwestern Norway and the valley of
Gudbrandsdalen. About half of the "alpine relief" area is characterized has steep slopes and
over-deepenedglacial valleys. The other half is made up of coastal mountains and intermediate-relief glacial valleys.[14]
^The overlap between the
Scandinavian Caledonides and the Scandinavian Mountains has led to various suggestions that the modern Scandinavian Mountains are a remnant of the Caledonide mountains.[23][25] A version of this argument was put forward in 2009 with the claim that the uplift of the mountains was attained by
buoyancy of the surviving "mountain roots" of the Caledonian
orogen.[23] This concept has been criticized since, at present, there is only a tiny "mountain root" beneath the southern Scandinavian Mountains and no "root" at all in the north. Further, the Caledonian Mountains in Scandinavia are known to have undergone
orogenic collapse for a long period starting in the
Devonian.[23][26][24] Another problem with this model is that it does not explain why other former mountains dating back to the
Caledonian orogeny are eroded and buried in sediments and not uplifted by their "roots".[23]
^After being first described by
Hans Reusch in 1901 the Paleic surface was subject of various interpretations in the 20th century.[23][28]
^Tormod Klemsdal regard the strandflat as old surfaces shaped by
deep weathering that escaped the uplift that affected the Scandinavian Mountains,[35] a view concordant with a
Triassic (c. 210 million years ago) origin for the strandflat postulated in the 2010s by Odleiv Olesen, Ola Fredin and their respective co-workers.[36][37] Yet
Hans Holtedahl claimed in 1998 that strandflats formed after a
Tertiary uplift the mountains noting however that in
Trøndelag between Nordland and
Western Norway the strandflat could be a surface formed before the
Jurassic, then buried in sediments and at some point freed from this cover.[38] Haakon Fossen and co-workers added to the debate in 2017 that movement of
geological faults in the Late Mesozoic should imply the strandflats of Western Norway took their final shape after the
Late Jurassic or else they would occur at various heights above sea level.[39]
^Redfield, T.F.; Osmundsen, P.T. (2013). "The long-term topographic response of a continent adjacent to a hyperextended margin: A case study from Scandinavia". GSA Bulletin. 125 (1/2): 184–200.
Bibcode:
2013GSAB..125..184R.
doi:
10.1130/B30691.1.
^
abcdefgCorner, Geoffrey (2004). "Scandes Mountains". In
Seppälä, Matti (ed.). The Physical Geography of Fennoscandia. Oxford University Press. pp. 240–254.
ISBN978-0-19-924590-1.
^Etzelmüller, Bernd; Romstad, Bård; Fjellanger, Jakob (2007). "Automatic regional classification of topography in Norway". Norwegian Journal of Geology. 87: 167–180.
^
abHall, Adrian M.; Ebert, Karin; Kleman, Johan; Nesje, Atle; Ottesen, Dag (2013). "Selective glacial erosion on the Norwegian passive margin". Geology. 41 (12): 1203–1206.
Bibcode:
2013Geo....41.1203H.
doi:
10.1130/g34806.1.
^Terrängformer i Norden (in Swedish). Nordiska ministerrådet. 1984. p. 10.
^King, Lorenz (1986). "Zonation and ecology of high mountain permafrost in Scandinavia". Geografiska Annaler. 68A (3): 131–139.
doi:
10.1080/04353676.1986.11880166.
^Jarsve, Erlend M.; Krøgli, Svein Olav; Etzelmüller, Bernd; Gabrielsen, Roy H. (2014). "Automatic identification of topographic surfaces related to the sub-Cambrian peneplain (SCP) in Southern Norway—Surface generation algorithms and implications". Geomorphology. 211: 89–99.
Bibcode:
2014Geomo.211...89J.
doi:
10.1016/j.geomorph.2013.12.032.
^
abLidmar-Bergström, K.; Näslund, J.O. (2002). "Landforms and uplift in Scandinavia". In Doré, A.G.; Cartwright, J.A.; Stoker, M.S.; Turner, J.P.; White, N. (eds.). Exhumation of the North Atlantic Margin: Timing, Mechanisms and Implications for Petroleum Exploration. Geological Society, London, Special Publications. The Geological Society of London. pp. 103–116.
^
abcdRedfied, T.F.; Osmundsen, P.T. (2013). "The long-term topographic response of a continent adjacent to a hyperextended margin: A case study from Scandinavia". GSA Bulletin. 125 (1): 184–200.
Bibcode:
2013GSAB..125..184R.
doi:
10.1130/B30691.1.
^Klemsdal, Tormod (2005). "Strandflat". In Schwartz, Maurice L. (ed.). Encyclopedia of Coastal Science. Encyclopedia of Earth Sciences Series. pp. 914–915.
ISBN978-1-4020-3880-8.
^Olesen, Odleiv; Kierulf, Halfdan Pascal; Brönner, Marco; Dalsegg, Einar; Fredin, Ola; Solbakk, Terje (2013). "Deep weathering, neotectonics and strandflat formation in Nordland, northern Norway". Norwegian Journal of Geology. 93: 189–213.
^Nielsen, S.B.; Paulsen, G.E.; Hansen, D.L.; Gemmer, L.; Clausen, O.R.; Jacobsen, B.H.; Balling, N.; Huuse, M.; Gallagher, K. (2002). "Paleocene initiation of Cenozoic uplift in Norway". In Doré, A.G.; Cartwright, J.A.; Stoker, M.S.; Turner, J.P.; White, N. (eds.). Exhumation of the North Atlantic Margin: Timing, Mechanisms and Implications for Petroleum Exploration. Geological Society, London, Special Publications. The Geological Society of London. pp. 103–116.