Mount Adams, New Zealand
Encyclopedia
Mount Adams is a mountain
in the West Coast
region of New Zealand
's South Island
. The summit is roughly 19 km south of Harihari
and reaches 2208 metres (7,244.1 ft) in height.
Mount Adams lies to the west of the main divide of the Southern Alps
and drains into the Whataroa
and Poerua
catchments. Both of these rivers flow westwards to the Tasman Sea
. There are two small glaciers on the south-eastern slopes that drain the summit ice cap; the Escape Glacier (about 2.1 km in length) and the Seige Glacier (about 3.6 km).
by world standards. There are no rainfall gauges
on Mount Adams, but a gauge in Whataroa valley at the State Highway 6 bridge 10 km south-west of the summit at 60 metres above sea level, records a mean annual rainfall of 5690mm (224 inches) and daily falls of up to 320mm (12 inches). It is likely that the precipitation at higher elevations on Mount Adams will be significantly greater than this, and a rain gauge in the Cropp River
42 km north-east of Mount Adams at 860 metres above sea level, records a mean annual rainfall of 10,690mm (421 inches) and daily falls of up to 695mm (27 inches).
runs across the lower North-western slopes of the mountain near the edge of the coastal outwash plain, and is the boundary between the Pacific
and Indo-Australian
tectonic plates. Mount Adams itself is composed primarily of schist
of Permian–Triassic (depositional) age, which is increasingly metamorphosed closer to the Alpine Fault.
On 6 October 1999, a large rock landslide
originating near the northern summit of Mount Adams deposited c.10-15 million cubic metres of rock in the Poerua River
1790 metres (5,872.7 ft) below. This created a 120 metre (390 ft) high landslide dam
, which formed a lake that extended 1.2 kilometres upstream. The dam failed six days later during heavy rain. Fears of major damage did not turn into reality when the dam was breached, though significant quantities of coarse gravel
were deposited downstream and the river's path was changed in places.
Although this route is technically not difficult, it involves multiple river crossings, off track travel up Dry Creek/Little Man River and above the bushline, and glacial travel requiring an ice axe and crampons. The overall elevation gain, from highway to summit, is approximately 2100 metres (6,889.8 ft). Most parties take two days to summit and return to SH6, though it is possible in a long summer day.
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
in the West Coast
West Coast, New Zealand
The West Coast is one of the administrative regions of New Zealand, located on the west coast of the South Island, and is one of the more remote and most sparsely populated areas of the country. It is made up of three districts: Buller, Grey and Westland...
region 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...
. The summit is roughly 19 km south of Harihari
Harihari
Hari Hari -Maori Meaning, from Te Aka Maori/English Dictionary is "To Take/Carry Joy" or, as local legend suggests, "Come together in Unison" from a Maori canoe paddling chant/song. In recent years, Hari Hari has been increasingly referred to as "Harihari" – Maori Meaning is "Ambulance"...
and reaches 2208 metres (7,244.1 ft) in height.
Mount Adams lies to the west of the main divide of the Southern Alps
Southern Alps
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...
and drains into the Whataroa
Whataroa River
The Whataroa River, sometimes the Wataroa River, is a river in the southern West Coast region of New Zealand's South Island. Its source is in the Southern Alps and it flows north and northwest, passing the township of Whataroa on the eastern side before reaching the Tasman Sea just south of Abut...
and Poerua
Poerua River
Poerua River is the name of two rivers in the West Coast region of New Zealand's South Island.The northern Poerua River flows from Lake Poerua into the Crooked River, which leads to Lake Brunner....
catchments. Both of these rivers flow westwards to the Tasman Sea
Tasman Sea
The Tasman Sea is the large body of water between Australia and New Zealand, approximately across. It extends 2,800 km from north to south. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European...
. There are two small glaciers on the south-eastern slopes that drain the summit ice cap; the Escape Glacier (about 2.1 km in length) and the Seige Glacier (about 3.6 km).
Climate
This area, like much of the West Coast region, is subject to high precipitationPrecipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
by world standards. There are no rainfall gauges
Rain gauge
A rain gauge is a type of instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a set period of time....
on Mount Adams, but a gauge in Whataroa valley at the State Highway 6 bridge 10 km south-west of the summit at 60 metres above sea level, records a mean annual rainfall of 5690mm (224 inches) and daily falls of up to 320mm (12 inches). It is likely that the precipitation at higher elevations on Mount Adams will be significantly greater than this, and a rain gauge in the Cropp River
Cropp River
The Cropp River is a river of New Zealand. It flows east for nine kilometres before joining the Whitcombe River, a tributary of the Hokitika River....
42 km north-east of Mount Adams at 860 metres above sea level, records a mean annual rainfall of 10,690mm (421 inches) and daily falls of up to 695mm (27 inches).
Geology
The Alpine FaultAlpine 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...
runs across the lower North-western slopes of the mountain near the edge of the coastal outwash plain, and is the boundary between the Pacific
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....
and Indo-Australian
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...
tectonic plates. Mount Adams itself is composed primarily of schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
of Permian–Triassic (depositional) age, which is increasingly metamorphosed closer to the Alpine Fault.
On 6 October 1999, a large rock landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
originating near the northern summit of Mount Adams deposited c.10-15 million cubic metres of rock in the Poerua River
Poerua River
Poerua River is the name of two rivers in the West Coast region of New Zealand's South Island.The northern Poerua River flows from Lake Poerua into the Crooked River, which leads to Lake Brunner....
1790 metres (5,872.7 ft) below. This created a 120 metre (390 ft) high landslide dam
Landslide dam
A landslide dam, debris dam, or barrier lake is a natural damming of a river by some kind of mass wasting: landslide, debris flow, rock avalanche or volcano. If it is caused by earthquake, it may also be called a quake lake. Some landslide dams are as high as the largest existing artificial dam...
, which formed a lake that extended 1.2 kilometres upstream. The dam failed six days later during heavy rain. Fears of major damage did not turn into reality when the dam was breached, though significant quantities of coarse gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
were deposited downstream and the river's path was changed in places.
Access
Mount Adams is unique in that it is one of the only glaciated peaks situated on or to the west of the main divide that is accessible as a weekend trip from a west coast road end. The standard route to the summit starts from a hidden layby off SH6 and heads up Dry Creek/Little Man River to a steep spur where a marked route starts. The marked route ends at the bushline and the remainder of the climb is on tussock, rock, and eventually the summit ice cap glacier.Although this route is technically not difficult, it involves multiple river crossings, off track travel up Dry Creek/Little Man River and above the bushline, and glacial travel requiring an ice axe and crampons. The overall elevation gain, from highway to summit, is approximately 2100 metres (6,889.8 ft). Most parties take two days to summit and return to SH6, though it is possible in a long summer day.