Xtra News Community 2
September 21, 2020, 10:13:33 pm
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Welcome to Xtra News Community 2 please also join our XNC2-BACKUP-GROUP.
  Home Help Arcade Gallery Links BITEBACK! XNC2-BACKUP-GROUP Staff List Login Register  

New Zealand's glaciers

Pages: [1]   Go Down
Author Topic: New Zealand's glaciers  (Read 3042 times)
Admin Staff
Posts: 31084

Having fun in the hills!

« on: January 26, 2011, 10:01:46 am »

New Zealand's glaciers face great melt

By KIRSTY JOHNSTON - Stuff.co.nz | 11:42AM - Monday, 10 January 2011

UNDER THREAT: Franz Josef glacier could lose up to 75 per cent of it's mass by 2100.
UNDER THREAT: Franz Josef glacier could lose up to 75 per cent of it's mass by 2100.

NEW ZEALAND'S GLACIERS could shrink by more than 75 per cent by the end of the century, contributing to an expected 12 centimetre rise in sea levels, a study says.

The research, published in Nature Geoscience this week, predicts that, globally, mountain glaciers and ice caps will lose 15 to 27 per cent of their volume by 2100.

One of the first such studies to provide detailed projections by region, it warns "ice loss on such a scale may have substantial impacts on regional hydrology and water availability".

Worst hit will be glaciers in the European Alps and New Zealand, with glaciers expected to shrink by more than 70 per cent due to the altitude, the nature of the terrain and the susceptibility to localised warming.

Glaciers in the Caucasus, western Canada and the western United States were projected to lose more than 50 per cent of their current ice volume.

Only 10 per cent shrinkage was predicted in Greenland and high-mountain Asia.

The scientists, from the University of British Columbia, say the melt-off will be responsible for increases in sea levels of between 8.7 and 16.1cm by 2100, supporting the change predicted by the UN climate change study from 2007.

Study leader Dr Valentina Radic said they were surprised at the amount the glaciers and caps contributed to the predicted rise in sea levels.

Currently, melt from smaller mountain glaciers and ice caps was responsible for a disproportionately large portion of sea level increases, even though they contained less than one per cent of water in glacier ice.

"What is surprising here is the contribution to sea level rises of up to 16cm just from the melting of small glaciers and ice caps. This may still be a low estimate as we did not include ice loss from calving — when a piece of ice breaks off into the sea," Radic told The Guardian newspaper.

Total sea level rises were likely to be considerably higher, however, due to the effects of melting Greenland and Antarctic ice sheets and thermal expansion of water, which were excluded from the results.

The scientists arrived at their conclusions by modelling volume loss and melt off from 120,000 mountain glaciers and ice caps. It is one of the first to provide detailed projections by region.

However, its projections didn't include glacier calving — the production of icebergs. Calving of tide-water glaciers may account for 30 per cent to 40 per cent of their total mass loss.

"Incorporating calving into the models of glacier mass changes on regional and global scale is still a challenge and a major task for future work," Radic said.

New Zealand has hundreds of glaciers, in both the North and South islands, with the most famous the Fox and Franz Josef on the South Island's West Coast.

Most of New Zealand's largest glaciers are in the Southern Alps, which have the highest mountains and heaviest rainfall. Glaciers in the Mount Cook area include the 29-kilometre-long Tasman and the Murchison (18 kilometres).

South of Mount Cook, the Bonar and Volta glaciers are centred around Mount Aspiring. Many, including the Olivine Ice Plateau, lie in the upper catchments of the Arawata, Matukituki, Dart and Hollyford rivers. The only glaciers in the North Island are found on Mount Ruapehu.

Report Spam   Logged

If you aren't living life on the edge, you're taking up too much space! 

Pages: [1]   Go Up
Jump to:  

Powered by EzPortal
Open XNC2 Smileys
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum

Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy
Page created in 0.016 seconds with 12 queries.