The Frans Josef Glacier

Courtesy of Wikipedia
The first European description of one of the west coast glaciers (believed to be Franz Josef) was made in the log of the ship Mary Louisa in 1859. The glacier was later named after Emperor Franz Joseph I of Austria by the German explorer, Julius von Haast in 1865. The Māori name for the glacier is Kā Roimata o Hine Hukatere ('The tears of Hine Hukatere'), arising from a local legend: Hine Hukatere loved climbing in the mountains and persuaded her lover, Wawe, to climb with her. Wawe was a less experienced climber than Hine Hukatere but loved to accompany her until an avalanche swept Wawe from the peaks to his death. Hine Hukatere was broken-hearted and her many, many tears flowed down the mountain and froze to form the glacier. Following the passage of the Ngai Tahu Claims Settlement Act 1998, the name of the glacier was officially altered to Franz Josef Glacier / Kā Roimata o Hine Hukatere.

Advance and retreat


An aerial view down the glacier.

Historic variations of the terminus position of the Franz Josef Glacier and associated events.
Franz Josef Glacier is currently 12 km (7.5 mi) long and terminates 19 km (12 mi) from the Tasman Sea. Fed by a 20-square-kilometre (7.7 sq mi) large snowfield[7] at high altitude, it exhibits a cyclic pattern of advance and retreat, driven by differences between the volume of meltwater at the foot of the glacier and volume of snowfall feeding the névé. Franz Josef Glacier had periods of advances from 1946 to 1951 (340 m), 1965–1967 (400 m), 1983–1999 (1420 m) and 2004–2008 (280 m).[8] The glacier advanced rapidly during the Little Ice Age, reaching a maximum in the early eighteenth century. Having retreated several kilometres between the 1940s and 1980s, the glacier entered an advancing phase in 1984 and at times has advanced at the phenomenal (by glacial standards) rate of 70 cm a day. The flow rate is about 10 times that of typical glaciers. Over the longer term, the glacier has retreated since the last ice age, and it is believed that it extended into the sea some 10,000 to 15,000 years ago.
This cyclic behaviour is well illustrated by a postage stamp issued in 1946, depicting the view from St James Anglican Church. The church was built in 1931, with a panoramic altar window to take advantage of its location. By 1954, the glacier had disappeared from view from the church, but it reappeared in 1997. This is due to the highly variable conditions on the snowfield, which take around 5–6 years before they result in changes in the terminus location.
The glacier was still advancing until 2008, but since then it has entered a very rapid phase of retreat. As is the case for most other New Zealand glaciers which are mainly found on the eastern side of the southern alps, the shrinking process is attributed to global warming.
There have been some incidents of jökulhlaups (outbreak floods from water-filled ice tunnels) at the glacier, with one destroying a bridge on the access route in 1989.
Based on past variations, scientists expect that Franz Josef Glacier will retreat 5 km and lose 38% of its mass by 2100 in a mid-range scenario of warming.

Comments

Post a Comment

Popular posts from this blog

The Waitangi Treaty & The New Zealand Wars

Image
Much of the rest of this comes from Wikipedia to whom I give attribution and thanks. The highlights are mine; The Treaty of Waitangi  ( Māori :  Te Tiriti o Waitangi ) is a  treaty  first signed on 6 February 1840 by representatives of the  British Crown  and  Māori  chiefs from the  North Island  of  New Zealand . It is a document of central importance to the history and political constitution of the state of New Zealand, and has been highly significant in framing the political relations between New Zealand's government and the Māori population. The Treaty was written at a time when British colonists were pressuring the Crown to establish a colony in New Zealand, and when some Māori leaders had petitioned the British for protection against French forces. It was drafted with the intention of establishing a British  Governor of New Zealand , recognising Māori ownership of their lands, forests and other possession...
Read more

The remarkable earthquake isolation system at Wellington's Parliament House

Image
To make sure Parliament House and the Parliamentary Library are able to withstand an earthquake of up to 7.5 on the Richter Scale, a special engineering system of base isolation was used in their foundations during the strengthening and refurbishment project of 1992-1995. Most masonry buildings constructed prior to the Napier earthquake in 1931 were built with minimal lateral resistance. They are considered to be brittle structures, which are likely to collapse in a moderate earthquake. These parliamentary buildings came within this category. The original building foundations of Parliament House were laid in 1912 and consisted of a mix of gravel and cement. The Parliamentary Library consisted of two wings of a similar construction built in two phases, 1883 and 1899. By the 1980s, the foundations of both buildings were showing signs of deterioration and with the Wellington Fault within 400m of the parliamentary site, there was concern as to the likely impact of an earthquake on these...
Read more