Mount Adams is a mountain in the

West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...

region of New Zealand's

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

. The summit is roughly 19 km south of Harihari and reaches in height. Mount Adams lies to the west of the main divide of the

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...

and drains into the

Whataroa Whataroa is a small township in southern Westland on the West Coast of New Zealand's South Island. It is located on the western bank of the Whataroa River, with the village of Te Taho on the other side. passes through Whataroa on its route from R ...

and Poerua catchments. Both of these rivers flow westwards to the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...

. There are two small

glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving 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 ...

on the south-eastern slopes that drain the summit ice cap; the Escape Glacier (about 2.1 km in length) and the Siege Glacier (about 3.6 km).

Climate

This area, like much of the West Coast region, is subject to high

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

by world standards. There are no rainfall gauges on Mount Adams, but a gauge in Whataroa valley at the bridge 10 km south-west of the summit at 60 metres above sea level, records a mean annual rainfall of 5690 mm (224 inches) and daily falls of up to 320 mm (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 10,690 mm (421 inches) and daily falls of up to 695 mm (27 inches).

Geology

The

Alpine Fault The Alpine Fault is a geological fault that runs almost the entire length of New Zealand's South Island (c. 480 km) and forms the boundary between the Pacific Plate and the Indo-Australian Plate. The Southern Alps have been uplifted on the fa ...

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 The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

and

Indo-Australian all of this entry re immigration is a complete fabrication Indian Australians or Indo-Australians are Australians of Indian ancestry. This includes both those who are Australian by birth, and those born in India or elsewhere in the Indian d ...

tectonic plates. Mount Adams itself is composed primarily of

schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes o ...

of Permian–Triassic (depositional) age, which is increasingly metamorphosed closer to the Alpine Fault. On 6 October 1999, a large rock

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...

originating near the northern summit of Mount Adams deposited c.10–15 million cubic metres of rock in the Poerua River below. This created a 120-metre (390 ft) high

landslide dam A landslide dam or barrier lake is the natural damming of a river by some kind of landslide, such as a debris flow, rock avalanche or volcanic eruption. If the damming landslide is caused by an earthquake, it may also be called a quake lake. Some ...

, 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 is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

were deposited downstream and the river's path was changed in places. Summit of Mt Adams, New Zealand

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.Pat Barrett, 17 August 1999
"Top From the Top"
''Christchurch Press'', pg. 36. The overall elevation gain, from highway to summit, is approximately . Most parties take two days to summit and return to SH6, though it is possible in a long summer day.

References

{{DEFAULTSORT:Adams, Mount Westland District Mountains of the West Coast, New Zealand Southern Alps