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119-469: The most noted features of the national park are six of Sweden's thirteen peaks over 2,000 m (6,600 ft) located within the park's boundaries. Among these is the second highest mountain in Sweden, Sarektjåkkå , whilst the massif Áhkká is located just outside the park. The park has about 200 peaks over 1,800 m (5,900 ft), 82 of which have names. Sarek is also the name of a geographical area which

238-424: A cirque landform (alternatively known as a corrie or as a cwm ) – a typically armchair-shaped geological feature (such as a depression between mountains enclosed by arêtes ) – which collects and compresses through gravity the snow that falls into it. This snow accumulates and the weight of the snow falling above compacts it, forming névé (granular snow). Further crushing of the individual snowflakes and squeezing

357-470: A few tons every day, resulting in an annual total of 180,000 metric tons (400,000,000 lb). The sediment gives the river a grey-green colour and forms large deltas . The main delta is formed at the confluence of the Rapaätno with its principal tributary, the river Sarvesjokk. Just before the confluence, the river braids for nearly 10 km (6.2 mi), forming a zone called Rapaselet. The most noted of

476-601: A full day for hikers to traverse the pass. The region's first inhabitants arrived with the retreat of the inland seas 8,000 years ago. They were nomads who lived in Northern Scandinavia , and probably ancestors of the Samis. Initially they were hunter-gatherers , living off reindeer. For those people, the mountains often had religious connotations, and several were Sieidi (places of worship). Offerings , such as antlers from reindeer, were often made in those places. One of

595-511: A glacier is usually assessed by determining the glacier mass balance or observing terminus behavior. Healthy glaciers have large accumulation zones, more than 60% of their area is snow-covered at the end of the melt season, and they have a terminus with a vigorous flow. Following the Little Ice Age 's end around 1850, glaciers around the Earth have retreated substantially . A slight cooling led to

714-595: A glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions , but glaciers may be found in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand . Between latitudes 35°N and 35°S, glaciers occur only in

833-411: A glacier via moulins . Streams within or beneath a glacier flow in englacial or sub-glacial tunnels. These tunnels sometimes reemerge at the glacier's surface. Most of the important processes controlling glacial motion occur in the ice-bed contact—even though it is only a few meters thick. The bed's temperature, roughness and softness define basal shear stress, which in turn defines whether movement of

952-408: A kilometer per year. Eventually, the ice will be surging fast enough that it begins to thin, as accumulation cannot keep up with the transport. This thinning will increase the conductive heat loss, slowing the glacier and causing freezing. This freezing will slow the glacier further, often until it is stationary, whence the cycle can begin again. The flow of water under the glacial surface can have

1071-404: A large effect on the motion of the glacier itself. Subglacial lakes contain significant amounts of water, which can move fast: cubic kilometers can be transported between lakes over the course of a couple of years. This motion is thought to occur in two main modes: pipe flow involves liquid water moving through pipe-like conduits, like a sub-glacial river; sheet flow involves motion of water in

1190-460: A lower heat conductance, meaning that the basal temperature is also likely to be higher. Bed temperature tends to vary in a cyclic fashion. A cool bed has a high strength, reducing the speed of the glacier. This increases the rate of accumulation, since newly fallen snow is not transported away. Consequently, the glacier thickens, with three consequences: firstly, the bed is better insulated, allowing greater retention of geothermal heat. Secondly,

1309-579: A minor section in the Scandinavian and Russian taiga . With regards to the flora and fauna, Sarek does not have a wide variety of species. This is mainly explained by the fact that most of the park, except the south and south-east part, is above the growth-limit of conifers, which is at an altitude of about 500 m (1,600 ft) in this region. Adding to this, unlike most of the region, Sarek National Park has few vast lakes or swamps . A total of approximately 380 species of vascular plants have been found in

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1428-430: A preferred habitat for numerous species of animals. Among the large carnivores, the brown bear is particularly frequent in the park and in the neighbouring Stora Sjöfallet. The bear fairly often also ventures into the subalpine region. The Eurasian lynx , classed as an endangered species in Sweden, is also found around the lakes of Rittak and Laitaure, and is also found in the subalpine forests of Rapa Valley. The red fox

1547-484: A thin layer. A switch between the two flow conditions may be associated with surging behavior. Indeed, the loss of sub-glacial water supply has been linked with the shut-down of ice movement in the Kamb ice stream. The subglacial motion of water is expressed in the surface topography of ice sheets, which slump down into vacated subglacial lakes. The speed of glacial displacement is partly determined by friction . Friction makes

1666-410: A tremendous impact as the iceberg strikes the water. Tidewater glaciers undergo centuries-long cycles of advance and retreat that are much less affected by climate change than other glaciers. Thermally, a temperate glacier is at a melting point throughout the year, from its surface to its base. The ice of a polar glacier is always below the freezing threshold from the surface to its base, although

1785-663: Is a stub . You can help Misplaced Pages by expanding it . Glacier A glacier ( US : / ˈ ɡ l eɪ ʃ ər / ; UK : / ˈ ɡ l æ s i ər , ˈ ɡ l eɪ s i ər / ) is a persistent body of dense ice that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries . It acquires distinguishing features, such as crevasses and seracs , as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques , moraines , or fjords . Although

1904-487: Is a bridge at the southernmost part of the stream ( 67°09′25.9″N 17°51′20.9″E  /  67.157194°N 17.855806°E  / 67.157194; 17.855806 ). Hikers can also follow the streams up to the glacier and cross there, although this requires knowledge about glacier crossing. The lack of marked trails and accommodations makes it very difficult for visitors to hike in the park in winter, unless they are experienced and properly equipped. The steep slopes of

2023-461: Is a moderate but steep hike up. The actual summit ( Stortoppen ) is located about 600 metres (2,000 ft) southwest of the north summit via a ridge and is not as easy to reach, requiring exposed scrambling. An alternative route is to scale the summit from the south by merely steep hiking, but this requires crossing glaciers . This article about a location in Norrbotten County , Sweden

2142-524: Is about 18 km (11 mi). As there is a boat connection between Rinim and the Sitojaure cabins on the Kungsleden, Pastavagge is a preferred route to and from central Sarek. The difference in altitude between the eastern entrance of the valley and the highest level of the pass is about 750 m (2,460 ft). Because of the steep climb, multiple fords and the high-alpine terrain, it usually takes at least

2261-456: Is above or at freezing at the interface and is able to slide at this contact. This contrast is thought to a large extent to govern the ability of a glacier to effectively erode its bed , as sliding ice promotes plucking at rock from the surface below. Glaciers which are partly cold-based and partly warm-based are known as polythermal . Glaciers form where the accumulation of snow and ice exceeds ablation . A glacier usually originates from

2380-407: Is affected by factors such as slope, ice thickness, snowfall, longitudinal confinement, basal temperature, meltwater production, and bed hardness. A few glaciers have periods of very rapid advancement called surges . These glaciers exhibit normal movement until suddenly they accelerate, then return to their previous movement state. These surges may be caused by the failure of the underlying bedrock,

2499-411: Is because these peaks are located near or in the hyperarid Atacama Desert . Glaciers erode terrain through two principal processes: plucking and abrasion . As glaciers flow over bedrock, they soften and lift blocks of rock into the ice. This process, called plucking, is caused by subglacial water that penetrates fractures in the bedrock and subsequently freezes and expands. This expansion causes

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2618-406: Is by basal sliding, where meltwater forms between the ice and the bed itself. Whether a bed is hard or soft depends on the porosity and pore pressure; higher porosity decreases the sediment strength (thus increases the shear stress τ B ). Porosity may vary through a range of methods. Bed softness may vary in space or time, and changes dramatically from glacier to glacier. An important factor

2737-434: Is called glaciology . Glaciers are important components of the global cryosphere . Glaciers are categorized by their morphology, thermal characteristics, and behavior. Alpine glaciers form on the crests and slopes of mountains. A glacier that fills a valley is called a valley glacier , or alternatively, an alpine glacier or mountain glacier . A large body of glacial ice astride a mountain, mountain range, or volcano

2856-416: Is called rock flour and is made up of rock grains between 0.002 and 0.00625 mm in size. Abrasion leads to steeper valley walls and mountain slopes in alpine settings, which can cause avalanches and rock slides, which add even more material to the glacier. Glacial abrasion is commonly characterized by glacial striations . Glaciers produce these when they contain large boulders that carve long scratches in

2975-488: Is divided into sharply defined zones, particularly in respect to the two neighbouring national parks. This is mainly due to the existence of diabase and diorite dikes which are more resistant to erosion. The park is intersected by a tangle of dikes created 608 million years ago, an era that probably corresponds with the first appearance of the rift during the formation of the Iapetus ocean. These dikes represent intrusions into

3094-628: Is higher, and the mountains above 5,000 m (16,400 ft) usually have permanent snow. Even at high latitudes, glacier formation is not inevitable. Areas of the Arctic , such as Banks Island , and the McMurdo Dry Valleys in Antarctica are considered polar deserts where glaciers cannot form because they receive little snowfall despite the bitter cold. Cold air, unlike warm air, is unable to transport much water vapor. Even during glacial periods of

3213-480: Is just as valid in the humid zones. In the montane region, the humid soils are covered with flowers such as the northern Labrador tea , cottonsedge , the Goldilocks buttercup , St Olaf's candlestick , common selfheal and common marsh-bedstraw . In the subalpine zone, the humid prairies mainly have mats of Globe-flower , kingcup and twoflower violet . In the alpine region there are many subalpine plants as well as

3332-459: Is labelled as an endangered species in Sweden with an estimate of 360 individuals in the country in 2000. The Arctic fox is a critically endangered species in Sweden, with only 50 individuals in the whole country. They dig extensive networks of tunnels in areas above the tree-line, with several families inhabiting the same sett . The park is one of the last sanctuaries for the gray wolf , a species also critically endangered in Sweden. In 1974–1975,

3451-509: Is made up of three types of landscape, sometimes difficult to differentiate between: large valleys, massive mountains, and high plateaux. The largest valley of the park, which is also the most noted, is the Rapa Valley . This valley occupies 40 km (15 sq mi) of the park, including several branches, the most important of which are the Sarvesvagge, which climbs as far as Padjelanta,

3570-419: Is not completely understood; it appears that favourable weather, and therefore a surplus of food, results in sudden population growths, but the reason for the decline is less obvious, although it is certain that contagious diseases play some role. These cycles are also reflected in the populations of animals who prey on the lemmings. Many birds living at this altitude are associated with the humid zones. However,

3689-498: Is relatively frequent, and is gradually extending its territory into the higher zones, where it competes with the arctic fox . Some small mammals that are frequent in the park are the European pine marten , the least weasel and the stoat . The ermine is also found in the higher regions. The herbivores include a very large number of moose as the forests and humid zones provide them with much food. They often grow to an impressive size in

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3808-594: Is still a matter of debate. The rocks of the Scandinavian Mountains were put in place by the Caledonian orogeny , forming a belt of deformed and displaced rocks now known as the Scandinavian Caledonides . Caledonian rocks overlie rocks of the much older Svecokarelian and Sveconorwegian provinces . The Caledonian rocks actually form large nappes ( Swedish : skollor ) that have been thrusted over

3927-897: Is termed an ice cap or ice field . Ice caps have an area less than 50,000 km (19,000 sq mi) by definition. Glacial bodies larger than 50,000 km (19,000 sq mi) are called ice sheets or continental glaciers . Several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces. The only extant ice sheets are the two that cover most of Antarctica and Greenland. They contain vast quantities of freshwater, enough that if both melted, global sea levels would rise by over 70 m (230 ft). Portions of an ice sheet or cap that extend into water are called ice shelves ; they tend to be thin with limited slopes and reduced velocities. Narrow, fast-moving sections of an ice sheet are called ice streams . In Antarctica, many ice streams drain into large ice shelves . Some drain directly into

4046-519: Is the part of the country that mostly resembles an alpine countryside. Within the park are 19 summits higher than 1,900 m (6,200 ft), the most noted being the second highest summit in Sweden after the Kebnekaise – the Sarektjåkkå with a height of 2,089 m (6,854 ft). The lowest altitude in the park is found in the southwest, near Lake Rittakjaure, at 477 m (1,565 ft). The park

4165-413: Is the region where there is a net loss in glacier mass. The upper part of a glacier, where accumulation exceeds ablation, is called the accumulation zone . The equilibrium line separates the ablation zone and the accumulation zone; it is the contour where the amount of new snow gained by accumulation is equal to the amount of ice lost through ablation. In general, the accumulation zone accounts for 60–70% of

4284-402: Is the underlying geology; glacial speeds tend to differ more when they change bedrock than when the gradient changes. Further, bed roughness can also act to slow glacial motion. The roughness of the bed is a measure of how many boulders and obstacles protrude into the overlying ice. Ice flows around these obstacles by melting under the high pressure on their stoss side ; the resultant meltwater

4403-552: Is then forced into the cavity arising in their lee side , where it re-freezes. As well as affecting the sediment stress, fluid pressure (p w ) can affect the friction between the glacier and the bed. High fluid pressure provides a buoyancy force upwards on the glacier, reducing the friction at its base. The fluid pressure is compared to the ice overburden pressure, p i , given by ρgh. Under fast-flowing ice streams, these two pressures will be approximately equal, with an effective pressure (p i – p w ) of 30 kPa; i.e. all of

4522-503: The Pedicularis sceptrum-carolinum , and the vegetation decreases as the altitude increases. The humid zones of the park are well known for their rich diversity of birds. The common crane , the wood sandpiper and the short-eared owl are found at the lower altitudes, while the Eurasian teal , the Eurasian wigeon , the greater scaup , the red-breasted merganser , the sedge warbler and

4641-952: The Andes , the Himalayas , the Rocky Mountains , the Caucasus , Scandinavian Mountains , and the Alps . Snezhnika glacier in Pirin Mountain, Bulgaria with a latitude of 41°46′09″ N is the southernmost glacial mass in Europe. Mainland Australia currently contains no glaciers, although a small glacier on Mount Kosciuszko was present in the last glacial period . In New Guinea, small, rapidly diminishing, glaciers are located on Puncak Jaya . Africa has glaciers on Mount Kilimanjaro in Tanzania, on Mount Kenya , and in

4760-636: The Faroe and Crozet Islands were completely glaciated. The permanent snow cover necessary for glacier formation is affected by factors such as the degree of slope on the land, amount of snowfall and the winds. Glaciers can be found in all latitudes except from 20° to 27° north and south of the equator where the presence of the descending limb of the Hadley circulation lowers precipitation so much that with high insolation snow lines reach above 6,500 m (21,330 ft). Between 19˚N and 19˚S, however, precipitation

4879-750: The Himalayas , Andes , and a few high mountains in East Africa, Mexico, New Guinea and on Zard-Kuh in Iran. With more than 7,000 known glaciers, Pakistan has more glacial ice than any other country outside the polar regions. Glaciers cover about 10% of Earth's land surface. Continental glaciers cover nearly 13 million km (5 million sq mi) or about 98% of Antarctica 's 13.2 million km (5.1 million sq mi), with an average thickness of ice 2,100 m (7,000 ft). Greenland and Patagonia also have huge expanses of continental glaciers. The volume of glaciers, not including

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4998-627: The Jokkmokk parish of the Church of Sweden , and church service is held throughout July. Just above the canyon, formed by Smailajåkk as it descends toward Rapaätno, there is a cabin for the National Park Service ( 67°22′38″N 17°38′42″E  /  67.37722°N 17.64500°E  / 67.37722; 17.64500 ). There is also a bridge over the Smailajåkk canyon which allows hikers to cross

5117-576: The Laurentia and Baltica plates , 450 to 250 million years ago, with the disappearance of the Iapetus Ocean by subduction . This happened just before the formation of the chain and was caused by the appearance of a rift , which finally led to the creation of the Atlantic Ocean . The chain, once split open, continued to erode until it formed a peneplain . Starting about 60 million years ago, both

5236-665: The Pårte observatory ) was built in the early 1900s by Swedish mineralogist and geographer Axel Hamberg . All the building material for the huts had to be carried to the site by porters . In Sarek National Park, as in the most of Sápmi, a large number of the locations have names originating from the Sami languages . These languages have several variations and their written forms have changed over time, which explains why some placenames do not always correspond with each other in different sources. The most common Sami names for locations or features in

5355-551: The Quaternary , Manchuria , lowland Siberia , and central and northern Alaska , though extraordinarily cold, had such light snowfall that glaciers could not form. In addition to the dry, unglaciated polar regions, some mountains and volcanoes in Bolivia, Chile and Argentina are high (4,500 to 6,900 m or 14,800 to 22,600 ft) and cold, but the relative lack of precipitation prevents snow from accumulating into glaciers. This

5474-521: The Rwenzori Mountains . Oceanic islands with glaciers include Iceland, several of the islands off the coast of Norway including Svalbard and Jan Mayen to the far north, New Zealand and the subantarctic islands of Marion , Heard , Grande Terre (Kerguelen) and Bouvet . During glacial periods of the Quaternary, Taiwan , Hawaii on Mauna Kea and Tenerife also had large alpine glaciers, while

5593-426: The common redpoll , the brambling , the yellow wagtail , the northern wheatear and the bluethroat are characteristic of the birch forests. The willow ptarmigan is also more common in this area. The raptors present in the zone are the merlin and the rough-legged buzzard , which often nests on the cliffs. The gyrfalcon and the golden eagle usually prefer lower altitudes, but are nevertheless also found in

5712-467: The common reed bunting are common in the Laitaure delta and around Pårekjaure Lake. At higher altitudes, Vardojaure Lake is rich with birds, mostly ducks and also the European golden plover , characteristic of the alpine zone and sometimes found in the humid zones. Låotakjaure Lake, on the border of Padjelanta, is interesting from an ornithological point of view. Other rare species are also present, such as

5831-409: The common shrew and the field vole . This is also the reindeers ' habitat. The Sami people living within the borders of the park, have domesticated the reindeer that stay in this zone during spring and move up to the alpine zone in summer. Brown bears are common in the valleys of Tjoulta and Rapadalen. However, it is the quantity and variety of birds is that enriches this zone. The willow warbler ,

5950-490: The drainage basin , from these waters, is the most significant in Sweden. The flow fluctuates strongly with the seasons, having an average of 100 m⋅s in July and about 4 m⋅s in winter, resulting in an average annual flow of approximately 30 m⋅s. The river also transports a significant quantity of sediment . In summer, it can carry up to 5,000–10,000 metric tons (11,000,000–22,000,000 lb) of sediment daily. In winter it only carries

6069-504: The lesser white-fronted goose , the great snipe , the red-throated pipit , the long-tailed duck and the bar-tailed godwit . The Luottolako Plateau is also considered to be interesting, with the most significant concentration of purple sandpipers in Sweden. Arctic chars , trouts and common minnows are found in the park's lakes, rivers and streams. Sarek National Park is mainly a high-alpine area with hardly any accommodation for tourists. The Kungsleden hiking trail passes through

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6188-542: The tree line varies greatly throughout the park, from 600 m (2,000 ft) in the Tjoulta valley to over 800 m (2,600 ft) in the Rapa Valley. The birch forests also contain other species of trees. The number of rowan , grey alder , trembling poplar and hackberry is relatively high. The alpine blue-sow-thistle is very widespread in this zone and is the food the bears prefer. Garden angelica also grows in

6307-448: The 1990s and 2000s. In a study using data from January 1993 through October 2005, more events were detected every year since 2002, and twice as many events were recorded in 2005 as there were in any other year. Ogives or Forbes bands are alternating wave crests and valleys that appear as dark and light bands of ice on glacier surfaces. They are linked to seasonal motion of glaciers; the width of one dark and one light band generally equals

6426-731: The Kuopervagge ;— with an area of nearly 20 km (7.7 sq mi) — and the Ruotesvagge, surrounded by numerous glaciers, including those of Mount Sarektjåkkå. Among the other notable valleys, outside the Rapadalen network, are the Kukkesvagge that makes up the north-eastern border of the park, and the Njåtsosvagge near the southern border. The largest plateau is the Ivarlako, east of

6545-451: The Norwegian border. The area of the park is 1,977 km (763 sq mi) and it is adjacent to the national parks Padjelanta (in the west) and Stora Sjöfallet (in the north). The parks have a combined area of approximately 5,500 km (2,100 sq mi). There are also a number of nature reserves nearby. Sarek National Park is the most mountainous region in Sweden and it

6664-502: The Pårte massif , with an altitude starting at 660–850 m (2,170–2,790 ft). West of Pårte, the Luottolako plateau covers an area of 45 km (17 sq mi) and has an even higher altitude at 1,200–1,400 m (3,900–4,600 ft). Interspersed between the valleys and the plateaux, are massive mountains, often with several summits. The main ones are: The park's main river is

6783-571: The Rapa River ( Rapaätno ). It originates from the glaciers of Sarektjåkkå and runs down the Rapa Valley as far as Lake Laitaure , and continues outside the park, where it joins with the Lesser Lule River which becomes a tributary of the Lule River at its confluence. This river is fed by thirty glaciers, contributing to a significant flow. The specific flow, the ratio between the average flow and

6902-399: The Rapa Valley. In general, the transition between the conifer forests and the ones consisting of birch is more or less gradual, with the number of birches present in the coniferous forests increasing along with the altitude until the conifers have completely disappeared. The size of the trees also diminishes with increasing altitude. The upper altitude limit for the forests — which is also

7021-608: The Sarektjåkkå nappe , which is composed of sediments probably deposited in the rift basin. The park has over 100 glaciers, making it one of the most glacier-rich areas in Sweden. The glaciers are relatively small, the largest being Pårtejekna in Pårte at 11 km (4.2 sq mi). However, some of the others are relatively large for Sweden, since the largest Swedish glacier, Stuorrajekna in Sulitelma (south of Padjelanta), measures 13 km (5.0 sq mi). The evolution of

7140-608: The Scandinavian and the North-American sections suffered a tectonic uplift . It is unclear what causes this and several hypotheses have been presented. One of the theories is the influence of the Iceland hotspot which could have raised the crust. Another hypothesis is the isostasy related to glaciations caused the uplift. In any of those cases, the uplift allowed the ancient mountain chain to rise several thousand metres. The area of

7259-412: The advance of many alpine glaciers between 1950 and 1985, but since 1985 glacier retreat and mass loss has become larger and increasingly ubiquitous. Glaciers move downhill by the force of gravity and the internal deformation of ice. At the molecular level, ice consists of stacked layers of molecules with relatively weak bonds between layers. When the amount of strain (deformation) is proportional to

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7378-520: The air from the snow turns it into "glacial ice". This glacial ice will fill the cirque until it "overflows" through a geological weakness or vacancy, such as a gap between two mountains. When the mass of snow and ice reaches sufficient thickness, it begins to move by a combination of surface slope, gravity, and pressure. On steeper slopes, this can occur with as little as 15 m (49 ft) of snow-ice. In temperate glaciers, snow repeatedly freezes and thaws, changing into granular ice called firn . Under

7497-479: The alpine zone has its own characteristic species, such as the rock ptarmigan , the snowy owl , the horned lark , the meadow pipit , the snow bunting and the Lapland longspur . Although the park does not have the vast marshes and lakes characteristic of the rest of the region, water is nevertheless present everywhere. The humid zones are rich with a great diversity of flora and fauna. The stratification of vegetation

7616-430: The amount of melting at surface of the glacier, the faster the ice will flow. Basal sliding is dominant in temperate or warm-based glaciers. The presence of basal meltwater depends on both bed temperature and other factors. For instance, the melting point of water decreases under pressure, meaning that water melts at a lower temperature under thicker glaciers. This acts as a "double whammy", because thicker glaciers have

7735-713: The annual movement of the glacier. Ogives are formed when ice from an icefall is severely broken up, increasing ablation surface area during summer. This creates a swale and space for snow accumulation in the winter, which in turn creates a ridge. Sometimes ogives consist only of undulations or color bands and are described as wave ogives or band ogives. Glaciers are present on every continent and in approximately fifty countries, excluding those (Australia, South Africa) that have glaciers only on distant subantarctic island territories. Extensive glaciers are found in Antarctica, Argentina, Chile, Canada, Pakistan, Alaska, Greenland and Iceland. Mountain glaciers are widespread, especially in

7854-438: The area during summer. The walls of the building were dry set from local stone and the roof was made of timber, transported from Kvikkjokk, 60 km (37 mi) away. Originally, service was held every summer on June   25. It took the minister from Kvikkjokk three days to reach the chapel, and three days to get back. It was abandoned in the mid-19th century and renovated in 1961, and is still in use. As of 2015, it belongs to

7973-432: The bedrock has frequent fractures on the surface, glacial erosion rates tend to increase as plucking is the main erosive force on the surface; when the bedrock has wide gaps between sporadic fractures, however, abrasion tends to be the dominant erosive form and glacial erosion rates become slow. Glaciers in lower latitudes tend to be much more erosive than glaciers in higher latitudes, because they have more meltwater reaching

8092-445: The bedrock. By mapping the direction of the striations, researchers can determine the direction of the glacier's movement. Similar to striations are chatter marks , lines of crescent-shape depressions in the rock underlying a glacier. They are formed by abrasion when boulders in the glacier are repeatedly caught and released as they are dragged along the bedrock. The rate of glacier erosion varies. Six factors control erosion rate: When

8211-404: The border of the park. Due to the lack of shelters combined with rapidly shifting weather and rough terrain, it is recommended that hikers are well prepared and experienced before setting out on the trails of the park. There are few bridges in the park, and crossing streams (Sami: jokk ) and rivers (Sami: ätno ) can be dangerous for ill-equipped or inexperienced hikers. Warm weather increases

8330-559: The created ice's density. The word glacier is a loanword from French and goes back, via Franco-Provençal , to the Vulgar Latin glaciārium , derived from the Late Latin glacia , and ultimately Latin glaciēs , meaning "ice". The processes and features caused by or related to glaciers are referred to as glacial. The process of glacier establishment, growth and flow is called glaciation . The corresponding area of study

8449-467: The deep profile of fjords , which can reach a kilometer in depth as ice is topographically steered into them. The extension of fjords inland increases the rate of ice sheet thinning since they are the principal conduits for draining ice sheets. It also makes the ice sheets more sensitive to changes in climate and the ocean. Although evidence in favor of glacial flow was known by the early 19th century, other theories of glacial motion were advanced, such as

8568-483: The deformation to become a plastic flow rather than elastic. Then, the glacier will begin to deform under its own weight and flow across the landscape. According to the Glen–Nye flow law , the relationship between stress and strain, and thus the rate of internal flow, can be modeled as follows: where: The lowest velocities are near the base of the glacier and along valley sides where friction acts against flow, causing

8687-485: The deltas – and an emblem of the park – is the Laitaure delta ( Laitauredeltat ), which the river forms as it connects with Lake Laitaure. The other significant rivers correspond to the principal valleys listed above. Most of them make up the drainage basin of Lesser Lule River. The rivers in the north part of the park flow into Lake Akkajaure , in the Stora Sjöfallet National Park, forming part of

8806-457: The eastern part of the park, from Saltoluokta to Kvikkjokk . There are no cabins within the park, the Pårte, Aktse and Sitojaure cabins are just outside the park and they are accessible from both Saltoluokta and Kvikkjokk. The Padjelanta Trail ( Padjelantaleden ), running from Kvikkjokk to Akkajaure, skirts the park along its western rim at Tarraluoppal, where the Tarraluoppal cabin is just on

8925-418: The essentially correct explanation in the 1840s, although it was several decades before it was fully accepted. The top 50 m (160 ft) of a glacier are rigid because they are under low pressure . This upper section is known as the fracture zone and moves mostly as a single unit over the plastic-flowing lower section. When a glacier moves through irregular terrain, cracks called crevasses develop in

9044-413: The forests, reaching a height of 2 to 3 m (6.6 to 9.8 ft). Many other plants in this zone can also attain exceptional size. The division between the birch and coniferous forests is relatively blurred, with many of the animal species listed above also present in the subalpine zone. Some small mammals are found more frequently here than in the coniferous forests, particularly several rodents such as

9163-462: The forests. The vipers of the Rittak region frequently reach remarkable sizes. The subalpine zone mostly consists of old-growth birch forests. These forests are exceptional in terms of density and richness, making it possible for significant quantities of sediment material to be carried from the mountainside by the runoff and deposited in the watercourses. This kind of transfer is particularly noted in

9282-475: The fracture zone. Crevasses form because of differences in glacier velocity. If two rigid sections of a glacier move at different speeds or directions, shear forces cause them to break apart, opening a crevasse. Crevasses are seldom more than 46 m (150 ft) deep but, in some cases, can be at least 300 m (1,000 ft) deep. Beneath this point, the plasticity of the ice prevents the formation of cracks. Intersecting crevasses can create isolated peaks in

9401-453: The glacier to melt, creating a water source that is especially important for plants, animals and human uses when other sources may be scant. However, within high-altitude and Antarctic environments, the seasonal temperature difference is often not sufficient to release meltwater. Since glacial mass is affected by long-term climatic changes, e.g., precipitation , mean temperature , and cloud cover , glacial mass changes are considered among

9520-428: The glacier will be accommodated by motion in the sediments, or if it'll be able to slide. A soft bed, with high porosity and low pore fluid pressure, allows the glacier to move by sediment sliding: the base of the glacier may even remain frozen to the bed, where the underlying sediment slips underneath it like a tube of toothpaste. A hard bed cannot deform in this way; therefore the only way for hard-based glaciers to move

9639-504: The glacier's surface area, more if the glacier calves icebergs. Ice in the accumulation zone is deep enough to exert a downward force that erodes underlying rock. After a glacier melts, it often leaves behind a bowl- or amphitheater-shaped depression that ranges in size from large basins like the Great Lakes to smaller mountain depressions known as cirques . The accumulation zone can be subdivided based on its melt conditions. The health of

9758-526: The glaciers, particularly that of the Mikka (8 km (3.1 sq mi)) have been studied since the end of the 19th century, especially by mineralogist and geographer Axel Hamberg . The other glaciers in the park have an evolution similar to that of the Mikka: in 1883 to 1895 they were mostly receding, then advanced a little in 1900 to 1916, after which they started to recede again. Later they stabilised or grew, which

9877-403: The heaths, which are otherwise fairly monochrome. In the chalky soils of this subzone, the vegetation is very rich and forms prairies with mountain avens as the most characteristic species. purple saxifrage , velvetbells , alpine pussytoes and alpine veronica are also present. With increasing altitude, the dwarf willow and lichens become more prominent, forming a second zone. Gradually

9996-469: The highest mountain in the Laponian area at 2,089 metres (6,854 ft) AMSL . The mountain is located close to the eastern border of Sarek National Park , about 23 kilometres (14 mi) southwest of Suorva . Sarektjåkkå is not easily accessible by any nearby roads, so the approach normally takes a day or more of backcountry hiking. Accessing the north summit, at 2,054 metres (6,739 ft) altitude,

10115-672: The hydrographic network of Lule älv. The park also contains several lakes. The largest are the Alkajaure (altitude 751 m or 2,464 ft), on the border between the Sarek and the Padjelanta park, and the Pierikjaure (altitude 820 m or 2,690 ft) near the Stora Sjöfallet National Park. The Sarek National Park lies within the Scandinavian Mountains , a mountain chain whose origin

10234-614: The ice at the bottom of the glacier move more slowly than ice at the top. In alpine glaciers, friction is also generated at the valley's sidewalls, which slows the edges relative to the center. Mean glacial speed varies greatly but is typically around 1 m (3 ft) per day. There may be no motion in stagnant areas; for example, in parts of Alaska, trees can establish themselves on surface sediment deposits. In other cases, glaciers can move as fast as 20–30 m (70–100 ft) per day, such as in Greenland's Jakobshavn Isbræ . Glacial speed

10353-420: The ice sheets of Antarctica and Greenland, has been estimated at 170,000 km . Glacial ice is the largest reservoir of fresh water on Earth, holding with ice sheets about 69 percent of the world's freshwater. Many glaciers from temperate , alpine and seasonal polar climates store water as ice during the colder seasons and release it later in the form of meltwater as warmer summer temperatures cause

10472-544: The ice to act as a lever that loosens the rock by lifting it. Thus, sediments of all sizes become part of the glacier's load. If a retreating glacier gains enough debris, it may become a rock glacier , like the Timpanogos Glacier in Utah. Abrasion occurs when the ice and its load of rock fragments slide over bedrock and function as sandpaper, smoothing and polishing the bedrock below. The pulverized rock this process produces

10591-488: The ice, called seracs . Crevasses can form in several different ways. Transverse crevasses are transverse to flow and form where steeper slopes cause a glacier to accelerate. Longitudinal crevasses form semi-parallel to flow where a glacier expands laterally. Marginal crevasses form near the edge of the glacier, caused by the reduction in speed caused by friction of the valley walls. Marginal crevasses are largely transverse to flow. Moving glacier ice can sometimes separate from

10710-411: The idea that meltwater, refreezing inside glaciers, caused the glacier to dilate and extend its length. As it became clear that glaciers behaved to some degree as if the ice were a viscous fluid, it was argued that "regelation", or the melting and refreezing of ice at a temperature lowered by the pressure on the ice inside the glacier, was what allowed the ice to deform and flow. James Forbes came up with

10829-418: The increased pressure can facilitate melting. Most importantly, τ D is increased. These factors will combine to accelerate the glacier. As friction increases with the square of velocity, faster motion will greatly increase frictional heating, with ensuing melting – which causes a positive feedback, increasing ice speed to a faster flow rate still: west Antarctic glaciers are known to reach velocities of up to

10948-423: The infrared OH stretching mode of the water molecule. (Liquid water appears blue for the same reason. The blue of glacier ice is sometimes misattributed to Rayleigh scattering of bubbles in the ice.) A glacier originates at a location called its glacier head and terminates at its glacier foot, snout, or terminus . Glaciers are broken into zones based on surface snowpack and melt conditions. The ablation zone

11067-601: The location which has become a meeting place for hikers in the park. It is also a preferred location to start a climb to the top of the Sarektjåkkå (2,089 m (6,854 ft)), via the Mikkajekna glacier. Pastavagge (in Lule Sami Orthography called Basstavágge ) is a narrow valley, forming a pass, running from Pielavalta ( Bielavallda ) towards the east, ending north of Rinim on the shores of Lake Sitojaure ( Sijddojávrre ). The trekking distance from Pielvalta to Rinim

11186-463: The melting of the glaciers causing water levels to rise, therefore wading is often easier and safer early in the morning. The only ford across the Rapa River south of the Smaila Moot, is at Tielmaskaite. The ford is long and can only be used when waterlevels are low. Inexperienced hikers are recommended not to cross without a guide. The glacier jokk from Pårtejekna, Kåtokjåhkå, has no fords. There

11305-679: The most deformation. Velocity increases inward toward the center line and upward, as the amount of deformation decreases. The highest flow velocities are found at the surface, representing the sum of the velocities of all the layers below. Because ice can flow faster where it is thicker, the rate of glacier-induced erosion is directly proportional to the thickness of overlying ice. Consequently, pre-glacial low hollows will be deepened and pre-existing topography will be amplified by glacial action, while nunataks , which protrude above ice sheets, barely erode at all – erosion has been estimated as 5 m per 1.2 million years. This explains, for example,

11424-445: The most sensitive indicators of climate change and are a major source of variations in sea level . A large piece of compressed ice, or a glacier, appears blue , as large quantities of water appear blue , because water molecules absorb other colors more efficiently than blue. The other reason for the blue color of glaciers is the lack of air bubbles. Air bubbles, which give a white color to ice, are squeezed out by pressure increasing

11543-474: The most significant Sieidi was situated at the foot of Mount Skierfe (1,179 m (3,868 ft) high), at the entrance to the Rapa Valley. Samis from the entire region gathered in this place for ceremonies. Mount Apär itself, was believed to be the home of demons and legend tells of an illegitimate child's ghost inside it. Sarektj%C3%A5kk%C3%A5 Sarektjåkkå is the second highest mountain in Sweden and

11662-530: The national park is part of. The Sarek mountain district includes a total of eight peaks over 2,000 m (6,600 ft). Due to the long trek, the mountains in the district are seldom climbed. There are approximately 100 glaciers in Sarek National Park. Sarek is a popular area for hikers and mountaineers. Beginners in these disciplines are advised to accompany a guide since there are no marked trails or accommodations and only two bridges aside from those in

11781-538: The national park, and the eastern Sarek Mountains in particular, was the last of part of Fennoscandia to be deglaciated . The last remnants of the Fennoscandian Ice Sheet melted there slightly after 9,700 years BP . The mountain chain was renewed and after that it was subjected to a new period of glacial erosion. In the beginning of the Quaternary period, 15 million years ago, a significant glacial advance occurred. The glaciers began to grow and move into

11900-466: 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 implyed from the erosion that the nappes of Caledonian rock reached once further east than they do today. The erosion has left remaining massifs of Caledonian rocks and windows of Precambrian rock. The Caledonian orogeny resulted from the collision of

12019-526: The park are tjåkkå or tjåkko (mountain), vagge (valley), jåkkå or jåkko (stream), lako (plateau) and ätno (river). An example of this is Rapaätno , meaning Rapa River . These names are also the official Swedish names of the locations. Sarek National Park is situated in the Jokkmokk Municipality , Norrbotten County , Sweden, north of the Arctic Circle , 50 km (31.07 mi) from

12138-412: The park was home to the only remaining wild wolf living in Sweden. Although the wolf population is now growing, they have not yet achieved a stable number in the park. In addition to these three mammals, Norway lemmings are also found in the park. The number of lemmings varies extremely, with massive spikes in the population during some years, immediately followed by a very rapid decline. This phenomenon

12257-546: The park, as its upper limit is about 500 m (1,600 ft) below most altitudes in these northern latitudes . The flora of this zone is constituted by old-growth forests of conifers, with mainly Scots pines and including Norway spruces . The pines can become very tall, particularly those around Lake Rittak, in the south part of the park. The undergrowth is mostly covered with mosses and lichens , in particular reindeer lichen , and also with Vaccinium myrtillus , Empetrum nigrum and cowberry . The Sarek forests are

12376-496: The park, as well as 182 species of vertebrates , 24 mammals , 142 birds , 2 reptiles , 2 amphibians and 12 fish . Many of these species are on the Swedish red list of endangered species , notably the large carnivores. The vegetation follows a fairly strict altitudinal zonation , as a result of the climate, and implying a similar zonation of fauna , although this is often less strict. The montane zones are relatively rare in

12495-462: The park, with enormous antlers . The birds in Sarek include a number of owls , such as the Ural owl , and woodpeckers , particularly the Eurasian three-toed woodpecker . The grey-headed chickadee is also very common, as are the fieldfare , the song thrush and the redwing . Reptiles and amphibians, such as the viviparous lizard , the common frog and the common European viper , are mostly found in

12614-411: The park. The alpine zone is divided into several narrower zones. The first subzone is mostly characterized by heathland , with many alder shrubs , mosses and lichens, and frequently dense mats of crowberries . Different types of heaths can be distinguished. One type is mostly composed of a mix of alpine clubmoss and alpine bearberry . Cushion pink and Lapland lousewort bring autumn colour to

12733-426: The plants become more scarce, and above 1,500 m (4,900 ft) there are only 18 types of plants present. There are three rare mammals who live in this zone. The wolverine inhabits a vast territory, roaming as far as the coniferous forests in winter, but the alpine zone is their main territory. They mostly eat carrion , but they do also hunt living animals such as small rodents, birds and insects. The wolverine

12852-674: The pooling of meltwater at the base of the glacier  — perhaps delivered from a supraglacial lake  — or the simple accumulation of mass beyond a critical "tipping point". Temporary rates up to 90 m (300 ft) per day have occurred when increased temperature or overlying pressure caused bottom ice to melt and water to accumulate beneath a glacier. In glaciated areas where the glacier moves faster than one km per year, glacial earthquakes occur. These are large scale earthquakes that have seismic magnitudes as high as 6.1. The number of glacial earthquakes in Greenland peaks every year in July, August, and September and increased rapidly in

12971-410: The pressure of the layers of ice and snow above it, this granular ice fuses into denser firn. Over a period of years, layers of firn undergo further compaction and become glacial ice. Glacier ice is slightly more dense than ice formed from frozen water because glacier ice contains fewer trapped air bubbles. Glacial ice has a distinctive blue tint because it absorbs some red light due to an overtone of

13090-558: The sea, often with an ice tongue , like Mertz Glacier . Tidewater glaciers are glaciers that terminate in the sea, including most glaciers flowing from Greenland, Antarctica, Baffin , Devon , and Ellesmere Islands in Canada, Southeast Alaska , and the Northern and Southern Patagonian Ice Fields . As the ice reaches the sea, pieces break off or calve, forming icebergs . Most tidewater glaciers calve above sea level, which often results in

13209-409: The stagnant ice above, forming a bergschrund . Bergschrunds resemble crevasses but are singular features at a glacier's margins. Crevasses make travel over glaciers hazardous, especially when they are hidden by fragile snow bridges . Below the equilibrium line, glacial meltwater is concentrated in stream channels. Meltwater can pool in proglacial lakes on top of a glacier or descend into the depths of

13328-419: The stream safely. The bridge is removed every winter and put back in the spring, after the spring flood. The cabin is not open to hikers, but there is an emergency shelter as well as an emergency telephone and an outhouse there. The presence of the bridge and the fact that three of the major valleys in the park ( Routesvagge , Rapa Valley and Koupervagge ) converge there, has resulted in the name 'Smaila Moot' for

13447-423: The stress being applied, ice will act as an elastic solid. Ice needs to be at least 30 m (98 ft) thick to even start flowing, but once its thickness exceeds about 50 m (160 ft) (160 ft), stress on the layer above will exceeds the inter-layer binding strength, and then it'll move faster than the layer below. This means that small amounts of stress can result in a large amount of strain, causing

13566-438: The surface snowpack may experience seasonal melting. A subpolar glacier includes both temperate and polar ice, depending on the depth beneath the surface and position along the length of the glacier. In a similar way, the thermal regime of a glacier is often described by its basal temperature. A cold-based glacier is below freezing at the ice-ground interface and is thus frozen to the underlying substrate. A warm-based glacier

13685-448: The valleys also contributes to the risk for avalanches . Aktse is an old farm settlement on the Kungsleden trail, approximately 1.3 km (0.81 mi) outside the boundaries of the park. In 1788 a chapel was built at Alkavare ( 67°20′32.7″N 17°12′55.3″E  /  67.342417°N 17.215361°E  / 67.342417; 17.215361 ) for the Sami that were herding reindeer in

13804-435: The valleys where they gradually merged to form an ice sheet that covered the entire region. Several further glaciations followed, forming the current landscape, with glacial valleys, cirques , nunataks etc. The degree to which the chain was affected by the erosion depended mainly on the structure of the terrain, which explains the diversity in the topography of the area. The topography of Sarek, similar to that of Kebnekaise,

13923-536: The vicinity of its borders. The area is among those that receives the heaviest rainfall in Sweden, making hiking dependent on weather conditions. It is also intersected by turbulent streams that are hazardous to cross without proper training. The delta of the Rapa River is considered one of Europe's most noted views and the summit of mount Skierfe offers an overlook of that ice-covered, glacial , through valley. The Pårte Scientific Station in Sarek (also known as

14042-417: The weight of the ice is supported by the underlying water, and the glacier is afloat. Glaciers may also move by basal sliding , where the base of the glacier is lubricated by the presence of liquid water, reducing basal shear stress and allowing the glacier to slide over the terrain on which it sits. Meltwater may be produced by pressure-induced melting, friction or geothermal heat . The more variable

14161-529: Was interpreted as being caused by the increase in winter precipitation related to global warming . The effect of the raised summer temperatures has been taken into account when assessing the data. The receding of the glaciers has resumed at a particularly rapid pace during the first years of the 21st century. According to its WWF classification, Sarek National Park is situated in the Scandinavian Montane Birch forest and grasslands ecoregion , with

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