Southern Alps
Encyclopedia
The Southern Alps is a mountain range
extending along much of the length of New Zealand
's South Island
, reaching its greatest elevations near the island's western side. The term "Southern Alps" generally refers to the entire range, although separate names are given to many of the smaller ranges that form part of it.
The range includes the South Island's Main Divide, which separates the water catchment
s of the more heavily populated eastern side of the island from those on the west coast. Politically, the Main Divide forms the boundary between the Canterbury and West Coast Regions
.
, the highest point in New Zealand at 3754 metres (12,316.3 ft) and there are 16 other points in the range that exceed 3,000 metres in height. The mountains are cut through with glacial valleys and lakes. According to an inventory conducted in the late 1970s, the Southern Alps contained over 3000 glacier
s larger than a hectare, the longest of which – the Tasman Glacier
– is 29 kilometres in length down towards Lake Pukaki
. A chain of glacial lakes are found on the eastern side of the ridge from Lake Coleridge
in the north to Lake Wakatipu
in Otago in the south.
Settlements include Maruia Springs a spa near Lewis Pass
, the town of Arthur's Pass
and some lakeside resorts.
The Southern Alps were named by Captain Cook on March 23, 1770, who described their "prodigious height". They had previously been noted by Abel Tasman
in 1642, whose description of the South Island's west coast is often translated as "a land uplifted high".
The Southern Alps lie along a geological plate boundary, part of the Pacific Ring of Fire
, with the Pacific Plate
to the southeast pushing westward and colliding with the northward-moving Indo-Australian Plate
to the northwest. Over the last 45 million years, the collision has pushed up a 20 km thickness of rocks on the Pacific Plate to form the Alps, although much of this has been eroded away. Uplift has been fastest during the last 5 million years, and the mountains continue to be raised today by tectonic
pressure, causing earthquakes on the Alpine Fault
. Despite the substantial uplift, most of the relative motion along the Alpine Fault is sideways, not vertical.
The climate is cold with snow and ice year-round at the highest points.
Because of its orientation perpendicular to the prevailing westerly winds, the range creates excellent wave soaring conditions for glider
pilots. The town of Omarama
, in the lee of the mountains, has gained an international reputation for its gliding conditions. The prevailing westerlies also create a weather pattern known as the Nor'west arch
, in which moist air is pushed up over the mountains, forming an arch of cloud in an otherwise blue sky. This weather pattern is frequently visible in summer across Canterbury
and North Otago
. The 'Nor'wester' is a foehn wind similar to the Chinook
of Canada, where mountain ranges in the path of prevailing moisture laden winds force air upwards, thus cooling the air and condensing the moisture to rain, producing hot dry winds in the descending air lee of the mountains.
habitats and grassland with mountain beech forest at lower elevations (of the eastern side but not in Westland
). The cold windswept slopes above the treeline are covered with areas of fellfield
. To the east the Alps descend to the high grasslands of Canterbury and Otago
. Plants adapted to the alpine conditions include woody shrubs like Hebe
, Dracophyllum
, and Coprosma
, the conifer Snow Totara
(Podocarpus nivalis) and Carex
sedge grasses.
, a large parrot that was once hunted as a pest. There are also a number of endemic insects adapted to these high altitudes especially flies, moths, beetles, and bees. The beech forests of the lower elevations are important habitat for two birds; the Great Spotted Kiwi
(Apteryx haastii) and the South Island kaka (Nestor meridionalis meridionalis).
, and Aoraki/Mount Cook National Park
or [protected areas such as Lake Sumner Forest Park
. Indigenous plant life is affected by introduced animals such as red deer
(Cervus elaphus), chamois
(Rupicapra rupicapra), and Himalayan tahr
(Hemitragus jemlahicus) all of which have at times been targeted for culling, while the birds and reptiles are vulnerable to introduced predators.
Mountain range
A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...
extending along much of the length of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
's South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
, reaching its greatest elevations near the island's western side. The term "Southern Alps" generally refers to the entire range, although separate names are given to many of the smaller ranges that form part of it.
The range includes the South Island's Main Divide, which separates the water catchment
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
s of the more heavily populated eastern side of the island from those on the west coast. Politically, the Main Divide forms the boundary between the Canterbury and West Coast Regions
Regions of New Zealand
The region is the top tier of local government in New Zealand. There are 16 regions of New Zealand. Eleven are governed by an elected regional council, while five are governed by territorial authorities which also perform the functions of a regional council and thus are known as unitary authorities...
.
Location and description
The Southern Alps run 450 km north to south. The tallest peak is Aoraki/Mount CookAoraki/Mount Cook
Aoraki / Mount Cook is the highest mountain in New Zealand, reaching .It lies in the Southern Alps, the mountain range which runs the length of the South Island. A popular tourist destination, it is also a favourite challenge for mountain climbers...
, the highest point in New Zealand at 3754 metres (12,316.3 ft) and there are 16 other points in the range that exceed 3,000 metres in height. The mountains are cut through with glacial valleys and lakes. According to an inventory conducted in the late 1970s, the Southern Alps contained over 3000 glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
s larger than a hectare, the longest of which – the Tasman Glacier
Tasman Glacier
The Tasman Glacier is the largest of several glaciers which flow south and east towards the Mackenzie Basin from the Southern Alps in New Zealand's South Island. It is New Zealand's longest glacier.-Geography:...
– is 29 kilometres in length down towards Lake Pukaki
Lake Pukaki
Lake Pukaki is the largest of three roughly parallel alpine lakes running north-south along the northern edge of the Mackenzie Basin on New Zealand's South Island. The others are Lakes Tekapo and Ohau...
. A chain of glacial lakes are found on the eastern side of the ridge from Lake Coleridge
Lake Coleridge
Lake Coleridge is located in inland Canterbury, in New Zealand's South Island. Located 35 kilometres to the northwest of Methven, it has a surface area of 47 km²....
in the north to Lake Wakatipu
Lake Wakatipu
Lake Wakatipu is an inland lake in the South Island of New Zealand. It is in the southwest corner of Otago Region, near its boundary with Southland.With a length of , it is New Zealand's longest lake, and, at , its third largest...
in Otago in the south.
Settlements include Maruia Springs a spa near Lewis Pass
Lewis Pass
Lewis Pass is a mountain pass in the South Island of New Zealand.The northernmost of the three main passes across the Southern Alps, it is higher than the Haast Pass, but slightly lower than Arthur's Pass...
, the town of Arthur's Pass
Arthur's Pass
Arthur's Pass is a mountain pass in the Southern Alps of the South Island of New Zealand. It marks part of the boundary between the West Coast and Canterbury regions, 140 km from Christchurch and 95 km from Greymouth. The pass lies in a saddle between the valleys of the Otira River, a...
and some lakeside resorts.
The Southern Alps were named by Captain Cook on March 23, 1770, who described their "prodigious height". They had previously been noted by Abel Tasman
Abel Tasman
Abel Janszoon Tasman was a Dutch seafarer, explorer, and merchant, best known for his voyages of 1642 and 1644 in the service of the VOC . His was the first known European expedition to reach the islands of Van Diemen's Land and New Zealand and to sight the Fiji islands...
in 1642, whose description of the South Island's west coast is often translated as "a land uplifted high".
The Southern Alps lie along a geological plate boundary, part of the Pacific Ring of Fire
Pacific Ring of Fire
The Pacific Ring of Fire is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements...
, with the Pacific Plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
to the southeast pushing westward and colliding with the northward-moving Indo-Australian Plate
Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and surrounding ocean, and extends northwest to include the Indian subcontinent and adjacent waters...
to the northwest. Over the last 45 million years, the collision has pushed up a 20 km thickness of rocks on the Pacific Plate to form the Alps, although much of this has been eroded away. Uplift has been fastest during the last 5 million years, and the mountains continue to be raised today by tectonic
Tectonics
Tectonics is a field of study within geology concerned generally with the structures within the lithosphere of the Earth and particularly with the forces and movements that have operated in a region to create these structures.Tectonics is concerned with the orogenies and tectonic development of...
pressure, causing earthquakes on the Alpine Fault
Alpine Fault
The Alpine Fault is a geological fault, more specifically known as a right-lateral strike-slip fault, that runs almost the entire length of New Zealand's South Island. It forms a transform boundary between the Pacific Plate and the Indo-Australian Plate. Earthquakes along the fault, and the...
. Despite the substantial uplift, most of the relative motion along the Alpine Fault is sideways, not vertical.
The climate is cold with snow and ice year-round at the highest points.
Because of its orientation perpendicular to the prevailing westerly winds, the range creates excellent wave soaring conditions for glider
Glider aircraft
Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine. Mostly these types of aircraft are intended for routine operation without engines, though engine failure can...
pilots. The town of Omarama
Omarama
Omarama is a small township at the junction of State Highways 8 and 83, near the southern end of the Mackenzie Basin, in the South Island of New Zealand. Omarama is in the Waitaki District, in the historic Province of Otago...
, in the lee of the mountains, has gained an international reputation for its gliding conditions. The prevailing westerlies also create a weather pattern known as the Nor'west arch
Nor'west arch
The Nor'west arch is a weather pattern peculiar to the east coast of New Zealand's South Island. For this reason, it is also often referred to as the Canterbury arch. It is shown in an apparent arch of high white cloud in an otherwise clear blue sky over the Southern Alps, and is accompanied by a...
, in which moist air is pushed up over the mountains, forming an arch of cloud in an otherwise blue sky. This weather pattern is frequently visible in summer across Canterbury
Canterbury, New Zealand
The New Zealand region of Canterbury is mainly composed of the Canterbury Plains and the surrounding mountains. Its main city, Christchurch, hosts the main office of the Christchurch City Council, the Canterbury Regional Council - called Environment Canterbury - and the University of Canterbury.-...
and North Otago
North Otago
The district of North Otago in New Zealand covers the area of Otago between Shag Point and the Waitaki River, and extends inland to the west as far as the village of Omarama . The large east-coast town of Oamaru serves as North Otago's main centre...
. The 'Nor'wester' is a foehn wind similar to the Chinook
Chinook wind
Chinook winds , often called chinooks, commonly refers to foehn winds in the interior West of North America, where the Canadian Prairies and Great Plains meet various mountain ranges, although the original usage is in reference to wet, warm coastal winds in the Pacific Northwest.Chinook is claimed...
of Canada, where mountain ranges in the path of prevailing moisture laden winds force air upwards, thus cooling the air and condensing the moisture to rain, producing hot dry winds in the descending air lee of the mountains.
Flora
The mountains are rich in flora with about 25% of the country's plant species being found above the treeline in alpine plantAlpine plant
Alpine plants are plants that grow in the alpine climate, which occurs at high elevation and above the tree line. Alpine plants grow together as a plant community in alpine tundra.-Alpine plant diversity:...
habitats and grassland with mountain beech forest at lower elevations (of the eastern side but not in Westland
Westland District
Westland District is a territorial authority on the west coast of New Zealand's South Island. Its population is - Government :The Westland District is governed by an elected Council, headed by an elected Mayor. The Mayor is elected at large. The current Mayor is Maureen Pugh. Councillors are...
). The cold windswept slopes above the treeline are covered with areas of fellfield
Fellfield
A fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost and of wind give rise to characteristic plant forms in scree interstices.-Soil dynamics:...
. To the east the Alps descend to the high grasslands of Canterbury and Otago
Canterbury-Otago tussock grasslands
The Canterbury-Otago tussock grasslands are an ecoregion of South Island, New Zealand.-Location and description:This ecoregion is a large area of dry grassy plains between the east coast and the Southern Alps that form the spine of South Island, in the regions of Canterbury and Otago...
. Plants adapted to the alpine conditions include woody shrubs like Hebe
Hebe
Hebe may refer to:*Hebe , the goddess of youth in Greek mythology*Hebe , a genus of plants native to New Zealand*Hebe , a comics character in the Marvel Comics universe*6 Hebe, a main-belt asteroid...
, Dracophyllum
Dracophyllum
Dracophyllum is a genus of plants belonging to the family Ericaceae, formerly Epacridaceae. There are some one hundred or so species in the genus, mostly shrubs but also cushion plants and trees, found in New Zealand, Australia and New Caledonia. The name, Dracophyllum or Dragon-leaf refers to...
, and Coprosma
Coprosma
Coprosma is a genus of 108 species that are found in New Zealand , Hawaii , Borneo, Java, New Guinea, islands of the Pacific Ocean to Australia and the Juan Fernández Is. Many species are small shrubs with tiny evergreen leaves, but a few are small trees and have much larger leaves...
, the conifer Snow Totara
Podocarpus nivalis
Podocarpus nivalis is a species of conifer in the Podocarpaceae family.It is found only in New Zealand. It grows in the mountains and subalpine lands from 37° to the far south New Zealand about 46° South Latitude...
(Podocarpus nivalis) and Carex
Carex
Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...
sedge grasses.
Fauna
Wildlife of the mountains includes the endemic Rock Wren (Xenicus gilviventris) and the keaKea
The Kea is a large species of parrot found in forested and alpine regions of the South Island of New Zealand. About long, it is mostly olive-green with a brilliant orange under its wings and has a large narrow curved grey-brown upper beak. The Kea is the world's only alpine parrot...
, a large parrot that was once hunted as a pest. There are also a number of endemic insects adapted to these high altitudes especially flies, moths, beetles, and bees. The beech forests of the lower elevations are important habitat for two birds; the Great Spotted Kiwi
Great Spotted Kiwi
The Great Spotted Kiwi, Great Gray Kiwi, or Roroa, Apteryx haastii, is a species of kiwi endemic to the South Island of New Zealand. The Great Spotted Kiwi, as a member of the Ratites, is flightless. It is the largest of the kiwi...
(Apteryx haastii) and the South Island kaka (Nestor meridionalis meridionalis).
Threats and preservation
The mountains are inaccessible and retain their natural vegetation. A large proportion of the range is well protected as part of various national parks, notably the Westland Tai Poutini National Park, Mount Aspiring National ParkMount Aspiring National Park
Mount Aspiring National Park is located in the Southern Alps of the South Island of New Zealand, north of Fiordland National Park, and between Otago and south Westland. The park forms part of the Te Wahipounamu World Heritage site.-Geography:...
, and Aoraki/Mount Cook National Park
Aoraki/Mount Cook National Park
Aoraki/Mount Cook National Park is in the South Island of New Zealand near the town of Twizel. Aoraki/Mount Cook, New Zealand's highest mountain and Aoraki/Mount Cook village lie within the park...
or [protected areas such as Lake Sumner Forest Park
Lake Sumner Forest Park
thumb|right|Gabriel hut at lake Sumner Forest ParkLake Sumner Forest Park is located in the Canterbury region of the South Island of New Zealand.-External links:* - Lake Sumner Conservation Park* - Lake Sumner Forest Park tramping tracks...
. Indigenous plant life is affected by introduced animals such as red deer
Red Deer
The red deer is one of the largest deer species. Depending on taxonomy, the red deer inhabits most of Europe, the Caucasus Mountains region, Asia Minor, parts of western Asia, and central Asia. It also inhabits the Atlas Mountains region between Morocco and Tunisia in northwestern Africa, being...
(Cervus elaphus), chamois
Chamois
The chamois, Rupicapra rupicapra, is a goat-antelope species native to mountains in Europe, including the Carpathian Mountains of Romania, the European Alps, the Tatra Mountains, the Balkans, parts of Turkey, and the Caucasus. The chamois has also been introduced to the South Island of New Zealand...
(Rupicapra rupicapra), and Himalayan tahr
Himalayan Tahr
The Himalayan Tahr or Common Thar is a large ungulate related to the wild goat.-Habitat:...
(Hemitragus jemlahicus) all of which have at times been targeted for culling, while the birds and reptiles are vulnerable to introduced predators.