Alps
[alps]
Geology
Geologically, the Alps were formed during the Oligocene and Miocene epochs as a result of the pressure exerted on the Tethyan geosyncline as its Mesozoic and Cenozoic strata were squeezed against the stable Eurasian landmass by the northward-moving African landmass. The squeezing action formed great recumbent folds (nappes) that rose out of the sea and pushed northward, often breaking and sliding one over the other to form gigantic thrust faults. Crystalline rocks, which are exposed in the higher central regions, are the rocks forming Mont Blanc, the Matterhorn, and high peaks in the Pennine Alps and Hohe Tauern; limestone and other sedimentary rocks are predominant (but not continuously present) in the generally lower ranges to the north and south. Mont Blanc (15,771 ft/4,807 m) is the highest peak.
Permanently snowcapped peaks rise above the snowline—located between 8,000 ft and 10,000 ft (2,440-3,050 m)—and glaciers (the longest being Aletsch glacier) form the headwaters of many Alpine rivers. Glaciation (see glacier) was more extensive during the Pleistocene epoch and carved a distinctive mountain landscape—characterized as alpine—of arětes, cirques, matterhorns, U-shaped and hanging valleys, and long moraine-blocked lakes (such as Garda, Como, and Maggiore in the south and Zürich, Geneva, Thun, and Brienz in the north).
The Alps were the first mountain system to be extensively studied by geologists, and many of the geologic terms associated with mountains and glaciers originated there. The term alps has been applied to mountain systems around the world that exhibit similar traits to the Alps of Europe.
Economy
Below the snowline is a treeless zone of alpine pastures that have for generations been used for the summer grazing of goats and cattle. Agriculture is confined to the valleys and foothills, with fruit growing and viticulture on some sunny slopes. Hydroelectric power, used for industries in the mountains and in nearby regions, is generated from the many waterfalls and swift-flowing rivers. Tourism, based on the scenic attractions of the Alps and the mountaineering and winter sports they provide, is a major source of income; among the more famous resorts are Chamonix (France); Zermatt, Interlaken, St. Moritz, Davos, and Arosa (Switzerland); Sankt Anton, Innsbruck, Kitzbühel, Salzburg, and Bad Gastein (Austria); Berchtesgaden (Germany); Cortina d'Ampezzo and Bolzano (Italy); and Bled (Slovenia).
Alpine Regions
The Alps are divided by rivers and other topographic features into more than 40 subunits for which local names are commonly used. Well-known groups in the W Alps (from the Riviera to the Great St. Bernard Pass) include the Maritime, Ligurian, Cottian, and Graian alps, the Mont Blanc group, and Valle d'Aosta. The highest western peaks are Mont Blanc, Mont Pelvoux, Monte Viso, and the Gran Paradiso; the chief routes across this section are via the Mont Cénis Tunnel and the Great and Little St. Bernard passes. The Central Alps (between the Great St. Bernard and Brenner passes) include, in the south, the Pennine, Lepontine, Phaetian, and Ötztal alps; and, in the north, the Bernina, Glarus, Allgäu, and Bavarian alps. The principal peaks of the Central Alps are Monte Rosa, the Matterhorn, the Finsteraarhorn, the Jungfrau, and the Wildspitze; the chief routes are the Simplon Tunnel and the St. Gotthard, Grimsel, Furka, Splügen, Bernina, and Brenner passes. The E Alps comprise, in the south, the Dolomites, the Carnic Alps, and the Julian Alps; and, in the north, the Hohe Tauern and Niedere Tauern; the principal eastern peak is Grossglockner. Most major routes across the E Alps follow the Brenner and Semmering passes.
Bibliography
See The Alps, prepared by the National Geographic Society, Washington, D.C. (1973); R. Clark, The Alps (1973); B. Spencer, Walking in the Alps (1986); F. Fleming, Killing Dragons: The Conquest of the Alps (2000).
Licensed from Columbia University Press
Licensed from Columbia University Press
Mountain range, South Island, New Zealand. It extends almost the entire length of the island, and it is the highest range in Australasia. It has elevations from 3,000 ft (900 m) to over 10,000 ft (3,050 m), culminating in Mount Cook at 12,316 ft (3,754 m) high. Glaciers descend from the permanently snow-clad top of the range. The range divides the island climatically: the forested western slopes and narrow coastal plain are much wetter than the eastern slopes and wide Canterbury Plains. Much of the southwest area was designated a UNESCO World Heritage site in 1990.
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Range of the eastern Alps. It extends southeast from the Carnic Alps in northeastern Italy to the city of Ljubljana, Slvn. The highest peak is Triglav (9,396 ft [2,864 m]), also the highest point in Slovenia.
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Mountain range, southeastern Australia. The mountains form the southern end of the Great Dividing Range and the watershed between the headstreams of the Murrumbidgee River and the rivers flowing south to the Pacific Ocean. The highest peak is Mount Kosciusko. The valleys of the Australian Alps have been used for grazing, while the highlands have seen scattered mining ventures.
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Mountain system, south-central Europe. The Alps extend in a crescent about 750 mi (1,200 km) from the Mediterranean coast between France and Italy to Vienna and cover more than 80,000 sq mi (207,000 sq km). Several peaks rise above 10,000 ft (3,000 m); the highest is Mont Blanc. The Alps form a divide between the Atlantic Ocean, the Mediterranean Sea, and the Black Sea and give rise to several major European rivers, including the Rhône, Danube, and Po. Glaciers cover about 1,500 sq mi (3,900 sq km), mostly at elevations above 10,000 ft (3,000 m). The Saint Gotthard Pass is one of the Alps's notable tunnels. Grenoble, Innsbruck, and Bolzano are major Alpine cities.
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The highest mountain in the Alps is Mont Blanc, at , on the Italian-French border. All the main peaks of the Alps can be found in the list of mountains of the Alps and list of Alpine peaks by prominence.
Geography
Subdivision
The Alps are generally divided into the Western Alps and the Eastern Alps. The division is along the line between Lake Constance and Lake Como, following the Rhine. The Western Alps are higher, but their central chain is shorter and curved; they are located in Italy, France and Switzerland. The Eastern Alps (main ridge system elongated and broad) belong to Austria, Germany, Italy, Liechtenstein, Slovenia and Switzerland. The highest peaks of the Western Alps are Mont Blanc, , Mont Blanc de Courmayeur , the Dufourspitze and the other summits of the Monte Rosa group, and the Dom, . The highest peak in the Eastern Alps is Piz Bernina, .
The Eastern Alps are commonly subdivided according to the different lithology (rock composition) of the more central parts of the Alps and the groups at its northern and southern fringes:
- Northern Limestone Alps (from the Wienerwald to Bregenzerwald),including the Flyschzone. peaks up to
- Central Eastern Alps (Austria, Switzerland), peaks up to
- Southern Limestone Alps.
The border between the Central Alps and the Southern Limestone Alps is the Periadriatic Seam. The Northern Limestone Alps are separated from the Central Eastern Alps by the Grauwacken Zone
The Western Alps are commonly subdivided with respect to geography:
- Ligurian Alps
- Maritime Alps
- Cottian Alps
- Dauphiné Alps
- Graian Alps
- Chablais Alps
- Pennine Alps
- Bernese Alps
- Lepontine Alps
- Glarus Alps
- Appenzell Alps.
Series of lower mountain ranges run parallel to the main chain of the Alps, including the French Prealps. (See Alpine geography.)
The geologic subdivision is different and makes no difference between the Western and Eastern Alps: Helveticum in the north, Penninicum and Austroalpine system in the centre and south of the Periadriatic seam the Southern Alpine system and parts of the Dinarides (see Alpine Geology). 'Geographically, the Jura mountains do not belong to the Alps; geologically'', however, they do.
Main chain
The "main chain of the Alps" follows the watershed from the Mediterranean Sea to the Wienerwald, passing over many of the highest and most famous peaks in the Alps. From the Colle di Cadibona to Col de Tende it runs westwards, before turning to the north-west and then, near the Colle della Maddalena, to the north. Upon reaching the Swiss border, the line of the main chain heads approximately east-north-east, a heading it follows until its end near Vienna.
Principal passes
The Alps do not form an impassable barrier; they have been traversed for war and commerce, and later by pilgrims, students and tourists. Crossing places by road, train or foot are called passes. These are depressions in the mountains to which a valley leads from the plains and hilly pre-mountainous zones.
Climate
The Alps are a classic example of what happens when a temperate area at lower altitude gives way to higher elevation terrain. Elevations around the world which have cold climates similar to those found in polar areas have been called alpine. A rise from sea level into the upper regions of the atmosphere causes the temperature to decrease. The effect of mountain chains on prevailing winds is to carry warm air belonging to the lower region into an upper zone, where it expands in volume at the cost of a proportionate loss of heat, often accompanied by the precipitation of moisture in the form of snow or rain.
Political and cultural history
Little is known of the early dwellers in the Alps, save from the scanty accounts preserved by Roman and Greek historians and geographers. A few details have come down to us of the conquest of many of the Alpine tribes by Augustus. Also, recent research into Mitochondrial DNA indicates that MtDNA Haplogroup K very likely originated in or near the southeastern Alps approximately 12-15,000 years ago.
During the Second Punic War in 218 BC, The Carthaginian general Hannibal successfully crossed the alps along with an army numbering 38,000 infantry, 8,000 cavalry, and 37 war elephants. This was one of the most celebrated achievements of any military force in ancient warfare.
Much of the Alpine region was gradually settled by Germanic tribes (Langobards, Alemanni, Bavarii) from the 6th to the 13th centuries, the latest expansion corresponding to the Walser migrations.
It is not until the final breakup of the Carolingian Empire in the 10th and 11th centuries that it becomes possible to trace out the local history of the Alps.
Exploration
The higher regions of the Alps were long left to the exclusive attention of the people of the adjoining valleys, even when Alpine travellers (as distinguished from Alpine climbers) began to visit these valleys. The two men who first explored the regions of ice and snow were H.B. de Saussure (1740-1799) in the Pennine Alps, and the Benedictine monk of Disentis, Placidus a Spescha (1752-1833), most of whose ascents were made before 1806, in the valleys at the sources of the Rhine.
Travel and tourism
The Alps are popular both in summer and in winter as a destination for sightseeing and sports. Winter sports (alpine and Nordic skiing, tobogganing, snowshoeing, ski tours) can be practised in most regions from December to April, while in summer the Alps are popular with hikers, mountain bikers, paragliders, mountaineers, while many lakes attract swimmers, sailors and surfers. The lower regions and larger towns of the Alps are well accessed by motorways and main roads, but higher passes and by-roads can be treacherous even in summer. Many passes are closed in winter. A multitude of airports around the Alps (and some within), as well as long-distance rail links from all neighbouring countries, afford large numbers of travellers easy access from abroad.
Flora
A natural vegetation limit with altitude is given by the presence of the chief deciduous trees—oak, beech, ash and sycamore maple. These do not reach exactly to the same elevation, nor are they often found growing together; but their upper limit corresponds accurately enough to the change from a temperate to a colder climate that is further proved by a change in the wild herbaceous vegetation. This limit usually lies about above the sea on the north side of the Alps, but on the southern slopes it often rises to , sometimes even to .This region is not always marked by the presence of the characteristic trees. Human interference has nearly exterminated them in many areas, and, except for the beech forests of the Austrian Alps, forests of deciduous trees are rarely found. In many districts where such woods once existed, they have been replaced by the Scots pine and Norway spruce, which are less sensitive to the ravages of goats who are the worst enemies of such trees.
Above the forestry, there is often a band of short pine trees (Pinus mugo), which is in turn superseded by dwarf shrubs, typically Rhododendron ferrugineum (on acid soils) or Rhododendron hirsutum (on basic soils). Above this is the alpine meadow, and even higher, the vegetation becomes more and more sparse. At these higher altitudes, the plants tend to form isolated cushions. In the Alps, several species of flowering plants have been recorded above , including Ranunculus glacialis, Androsace alpina and Saxifraga biflora.
Fauna
Species common to the Alps. These are most numerous in the 15% of the Alps that are protected in parks and reserves.
See also
External links
- Satellite photo of the Alps, taken on 31 August 2005 by MODIS aboard Terra
- Images from the Alps Many images from Alps, landscape, flowers and wildlife.
- 360° Panoramic Views in Alps
- A virtual visit of Western Alps with 360° panoramic images
- A online picture collection of the Alps More than 2000 pictures of climbing, backcountry skiing, hiking, landscape
- Photos - Italian Alps - Santa Catarina
- Photos of alpin swiss landscapes and wildlife (Valais)
- Discover wildlife of the Alps with 60 representative photos
References
This article is licensed under the GNU Free Documentation License.
Last updated on Friday October 10, 2008 at 06:03:01 PDT (GMT -0700)
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