Tasman Valley |

If you are in the Mount Cook area, take a drive up the Tasman Valley for amazing views of Mount Cook, the Tasman glacier and Tasman Lake.

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. Although its upper reaches are snow-covered, rocks carried by the glacier are exposed along its course, and the lower glacier is entirely rock-covered.

The waters from both the Tasman and Murchison glaciers pool at the end of the glacier in Lake Tasman, before flowing south to join the outflow from the nearby Hooker and Mueller Glaciers in the wide valley of the Tasman River, they flow south into Lake Pukaki. They eventually flow into the Waitaki River and to the Pacific Ocean north of Oamaru.

The glacier has retreated about 180 mt (590 ft) a year on average since the 1990s and the glacier is now in a period of faster retreat where the rate of retreat is calculated to be between 477 to 822 mt (1,565 to 2,697 ft) each year. It is estimated that the Tasman Glacier will eventually disappear and the terminal Tasman Lake will reach a maximum size in 10 to 19 years time. In 1973 Tasman Glacier had no terminal lake, now it is estimated at 7 km long, 2 km wide, and 245 mt deep.

Looking east, back towards the main road

The magnitude 6.3 earthquake that devastated Christchurch was strong enough to shake 30 million tonnes of ice loose from Tasman Glacier which fell into the Tasman Lake. Two boats were hit with tsunami waves of up to 3.5 metres (11 ft) as the ice fell into the Tasman Lake under the glacier.

The Terminal Lake, is now over estimated to be 7 km, 2 km wide and 245 mt deep.

Tasman Lake looking back down the valley from the top of the moraine wall.

Mt Cook

A close up of the moraine wall with the debris covered Tasman Glacier to the right. The random assortment of mixed sized rocks that make up a typical moraine is clearly visible in the foreground.