Tasman Glacier. Photo: Dr Trevor Chinn,
Alpine and Polar Research, Hawea.
New Zealand’s glaciers are showing the lowest total ice mass on record and most are continuing to shrink at a rapid rate.
Research released by the National Institute of Water & Atmospheric Research (NIWA) shows the Southern Alps glaciers have lost 2.5 km³ (2.2 billion tonnes) of permanent ice from April 2007 to March 2008, the fourth highest annual loss since monitoring started.
The 2008 total ice volume estimate for the Southern Alps glaciers of 44.9 km³ is the lowest on record.
For the past 32 years NIWA has been surveying 50 glaciers in the Southern Alps, using a small fixed wing aircraft, to record the height of the snow line at the end of summer
NIWA Principal Scientist Dr Jim Salinger says the photographs taken on this year’s survey showed the glaciers had lost much more ice than they had gained during the past glacier year.
“As a result of La Niña conditions over New Zealand, more easterlies, and warmer than normal temperatures, there was less snowfall in the Southern Alps and more snowmelt.
The higher the snow line, the more snow is lost to feed the glacier. On average, the snow line this year was about 130 metres above where it would need to be to keep the ice mass constant,” Dr Salinger says.
Dr Salinger says these results match trends of ice mass lost globally. International monitoring of mountains glaciers by the World Glacier Monitoring Service in Switzerland shows most glaciers are retreating. Of the glaciers where continuous data is available, the mean annual average loss in ice thickness since 1980 is close to half a metre per year.
Editor's Note: Original news release can be found here.
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