Posts tagged “Westland NP

Glacier Movement

Franz Josef GlacierThe Franz Josef Glacier is one of the fastest moving glaciers on Earth. Unlike most of glacier in the world the Franz Josef Glacier travels down very steep slopes of the Southern Alps. In the upper and very steep parts of the glacier, where the ice in the huge neve is squeezed into a narrow valley, the ice can move up to 5m each day during period of advance. (more…)

Weather on the West Coast

New Zealand owes its stunning beauty to its location on Earth. This applies particularly well to the West Coast of the South Island. Due to the predominant weather patterns in this part of the globe, the South Island faces the weather sweeping in as a persistent westerly airstream from the Tasman Sea. Moisture laden clouds brought in by these westerly winds have a gigantic barrier in their way – The Southern Alps. The Alps force the clouds to climb into higher and colder altitudes so the clouds finally give up and release the moisture in form of rain, and around the Main Divide as snow. The annual precipitation on the West Coast reaches 16 meters in places, making the West Coast one of the wettest places on Earth.

Glacial Erosion

One of the most striking forms of evidence of glacial erosion is the colour of rivers like the Waiho River in Franz Josef. The melt water of the river gains a characteristic greyish colour, sometimes known as glacier milk. This is the result of the suspension of very fine grains of rock <0.002mm in size. These particles are called glacial flour and are the result of a type of glacial erosion known as abrasion. The abrasion occurs where the glacier slides over bedrock and works much like sandpaper, as rock fragments meet at the boundary of rock and ice they grind and smooth the surface below. If a large rock is trapped, large grooves or glacial striations are engraved into valley walls and bedrock.

Another major type of erosion is known as plucking. When the ice slides over the downstream side of the bedrock, it can freeze loosened rocks from the bottom into itself and rips the rocks out from the valley floor and walls, changing its shape forever.

Why the Glacial Ice is Blue?

One of the attractions of the glacier is the beautiful blue colour of its ice. In the upper reaches of the glacier the ice can be up to 300m thick. The upper layer is snow. When this reaches about 16 – 20m deep the snow compresses under its own weight and all the air is squeezed from between the snow crystals, forming glacial ice. (more…)

Magic Glaciers of the New Zealand’s West Coast

The unique environment of Westland National Park is responsible for the formation of the local glaciers. These powerful remnants of an ice age manage to survive warming temperatures due to the very special weather conditions on the West Coast of the South Island. Up to 16 metres of precipitation falls on the tops of the Southern Alps every year, most of it falling as snow. This massive amount of snow (more…)