Tasman Glacier

At in length, Tasman Glacier is still New Zealand's longest glacier, despite shrinking considerably from the 1990s onwards. Forrest Ross Glacier, named after Forrestina Ross), Kaufmann Glacier, Haast Glacier, Hochstetter Glacier, and Ball Glacier. The glacial terminal lake is met by the meltwater of the Murchison Glacier, which approaches from the northeast and flows alongside the Tasman Glacier outside the moraine wall. The waters of Tasman Lake flow into the Tasman River and flow south joining the Hooker River draining the proglacial lakes on the Hooker and Mueller Glaciers. The Tasman River exhibits a braided characteristic, and flows south into Lake Pukaki. They eventually flow into the Waitaki River and to the Pacific Ocean north of Oamaru. ==Recent retreat==

, Hooker and Tasman Glaciers in the Southern Alps, showing major retreat in the ~10 years circa 1990 to 2000. Notice the larger terminal lakes, the retreat of the white ice (ice free of moraine cover, high up on the glaciers), and (more subtly) the increase in height of the moraine walls due to ice thinning. The glacier remained at a constant in length for all of its recorded history in the 20th century before starting its current period of rapid melting in the 1990s. Since the 1990s the terminus has retreated about a year on average. The glacier is now in a period of faster retreat where the rate of retreat is calculated to be between 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 and by 2008 Tasman Lake was long, wide, and deep. of ice dropped from the terminal face of the Tasman Glacier and fell into the Tasman Lake. Boats were hit with tsunami waves of up to as the ice fell into the Tasman Lake under the glacier. Similar events in the past have been attributed to buoyancy effects, a result of high basal water pressures and increased lake level following heavy rainfall events.{{cite web | url=http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10708071 ==Access and tourism==

Tasman Glacier has a long history of tourism, with heli skiing tours offered on the upper glacier since the early 1970s. The tributary Ball Glacier was also popular for skiing, with national championships being held there in the 1930s. It has since diminished too far to be safely accessed. Similarly, Tasman Glacier's significant ice loss over the past decades has impacted tourism, The Ball Shelter Track, part of the Ball Hut Route, leads along the western side of the glacier, separated from Tasman Lake by a tall moraine wall until about 6 kilometres in, where it climbs high enough for the view to open up. At that point, the rock-covered lower Tasman Glacier in the valley between the moraine walls is wide. ==See also==