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Posts tagged Mackenzie Basin

Bright Blue Glacial Lakes of New Zealand’s South Island

44S 170.1E

January 11th, 2012 Category: Lakes

New Zealand - January 10th, 2012

The three bright blue, roughly parallel lakes in this image of New Zealand’s South Island are (from left to right): Lake Oahu, Lake Pukaki and Lake Tekapo. They are all alpine glacial lakes in the Mackenzie Basin, near the Southern Alps. The bright blue color comes from “glacial flour”, the extremely finely ground rock particles from glaciers feeding into the lakes.

Lake Oahu is the smallest of the three, with a surface area of 60 km². Lake Tekapo is the second-largest, covering an area of 83 km². Lake Pukaki is the largest of the three, covering an area of 178.7 km². Visible at the lake’s northern end is the Tasman River.


A Look at Both Sides of the Southern Alps, New Zealand

43.6S 170.6E

March 24th, 2011 Category: Mountains, Sediments

New Zealand - March 22nd, 2011

The Southern Alps run down the middle of New Zealand’s South Island, providing a sort of “backbone”. In this image, snow and clouds are present on the eastern side of the ridge, while the western side is clear.

Along the west coast, several rivers can be seen spilling sediments into the  Tasman Sea. Sediments are also present along the northern coastline, pouring into the Cook Strait. In the full image, sediments and/or algae can be seen giving a bright blue color to several glacial lakes in the Mackenzie Basin, at the eastern foot of the Alps.


Lakes Connected to the Waitaki River, New Zealand – March 16th, 2010

44.4S 170.2E

March 16th, 2010 Category: Lakes, Rivers, Sediments

New Zealand - February 23rd, 2010

New Zealand - February 23rd, 2010

The Waitaki River is a large river in the South Island of New Zealand, some 110 km long. It passes Kurow and Glenavy before entering the Pacific Ocean between Timaru and Oamaru on the east coast of the South Island. The rivermouth can be seen towards the bottom of this image, releasing sediments into the ocean. The median flow of the Waitaki River at Kurow is 356 cubic metres per second.

The Waitaki is the major river of the Mackenzie Basin. It is a braided river which flows through Lake Benmore, Lake Aviemore and Lake Waitaki (visible in reverse order upon tracing the river’s path upstream). These are ultimately fed by three large glacial lakes, Tekapo, Pukaki and Ohau (upper right quadrant, from northeast to southwest).

Lakes in New Zealand’s Mackenzie Basin – November 10th, 2009

44.1S 170.1E

November 10th, 2009 Category: Image of the day, Lakes, Rivers

New Zealand - October 22nd, 2009

New Zealand - October 22nd, 2009

The bright blue waters of several lakes stand out against the snowy white peaks of the Southern Alps on New Zealand’s South Island. These lakes are in the Mackenzie Basin, an elliptical intermontane basin, located in the Mackenzie and Waitaki Districts.

The largest such basin in the country, it extends approximately 100 kilometers (62 miles) north to south, and 40 kilometers (25 miles) east to west. The Southern Alps constitute its western edge. Aside from a few mountain passes, the terrain is generally highest at the northern end and gradually descends in a southward direction.

Prominent rivers crossing the Mackenzie Basin include the Waitaki, the Ahuriri, the Hakataramea and the Tekapo Rivers. Lakes Ohau, Pukaki, Alexandrina and Tekapo lie within the Mackenzie Basin, as do the artificial hydroelectric lakes of Ruataniwha, Benmore and Aviemore.

Here, moving diagonally downward from the  upper right is the bright turquoise Lake Tekapo, followed by Lake Pukaki and finally by the slightly darker turquoise Lake Ohau. South of these three is the artificial Lake Benmore. Outside the basin, the dark blue Lakes Hawea (right) and Wanaka (left) are visible near the left edge of the image.

New Zealand’s South Island – February 18th, 2009

February 18th, 2009 Category: Image of the day, Lakes

South Island, New Zealand - February 16th, 2009

South Island, New Zealand - February 16th, 2009

South Island lakes

South Island lakes

The diverse geographical features of New Zealand’s South Island, including the Southern Alps and a number of lakes, are visible in this fine image.

The Southern Alps is a mountain range which runs along the western side of the South Island of New Zealand, forming a natural dividing range along the island’s entire length. Aoraki/Mount Cook is the highest point, at 3754 metres (12,283 feet).

In the close-up, the largest lakes visible from bottom to top are: Wanaka, Hawea, Ohau, Pukaki and Tekapo.

Lake Wanaka is located in the Otago region of New Zealand, in a glacial valley at an altitude of 300 metres. Covering an area of 192 km2, it is New Zealand’s fourth largest lake, and estimated to be more than 300 m deep.

About eight kilometers to the East, at an altitude of 348 metres, also located in the Otago Region, lies Lake Hawea. It covers an area of some 141 km² and is, at its deepest, 392 metres deep. In 1958 the lake was raised artificially by 20 metres to store more water for increased hydroelectric power generation. At its greatest extent, which is roughly along a north-south axis, the lake is 35 kilometres long.

It lies in a glacial valley parallel to that of nearby Lake Wanaka. At their closest point (a rocky ridge called The Neck), the lakes are only 1000 metres apart. The only flat land around the lake is at its southern end, surrounding its outflow into the Hawea River, a short tributary of the Clutha, which it joins near Albert Town.

Further east, Lake Ohau forms part of the traditional boundary between Otago and Canterbury regions. It is a glacial lake in the Mackenzie Basin. It is fed by the Hopkins and Dobson rivers, which have their headwaters in the Southern Alps, and has its outflow in the Ohau River, which itself feeds into the Waitaki River hydroelectric project.

Covering 60 km², Ohau is the smallest of three roughly parallel lakes running north-south along the northern edge of the Mackenzie Basin (the others are Lake Pukaki and Lake Tekapo). All three lakes were created by receding glaciers blocking their respective valleys with their terminal moraine (a moraine-dammed lake). The glacial feed to the lakes gives them a distinctive blue colour, created by glacial flour (extremely finely ground rock particles from the glaciers).

Lake Pukaki is an alpine lake along the northern edge of the Mackenzie Basin. It covers an area of 169 km², and the normal operating range lake level is 518.2 to 532 metres above sea level. The lake is fed at its northern end by the braided Tasman River, which has its source in the Tasman and Hooker Glaciers, close to Aoraki/Mount Cook.

The lake’s original outflow was at its southern end, into the Pukaki River. The lake is now, however, an upper part of the Waitaki hydroelectric scheme. As a result, the outflow has been dammed, and the water flows out through a canal linking it to a canal carrying water from Lake Ohau.

Finally, Lake Tekapo, the largest of the three Mackenzie Basin lakes, covers an area of 83 km², and is at an altitude of 700 metres above sea level. The lake is fed at its northern end by the braided Godley River, which has its source in the Southern Alps, to the north.

source Wikipedia