Scientists drill ice for climate secrets

South Canterbury's Tasman Glacier may contain the oldest ice in the country.

Climate scientist Uwe Morgenstern has been collecting ice samples from Tasman Glacier as part of ongoing research to determine past weather patterns and climate changes in New Zealand.

Dr Morgenstern said ice samples taken from the top of Tasman Glacier revealed ice up to 90 years old, and his aim was to drill into the glacier's centre, where he hoped to find ice up to 200 years old.

The Geological and Nuclear Science researcher said glaciers were natural archives, which held information on past climatic and environmental changes.

"Ice cores act as natural archives on climate change and hold information from as far back as 150 years ago before human influence - so we can tell between human-induced and natural climate variations."

Dr Morgenstern will drill and collect ice core samples from several locations on glaciers over the next few years.

New Zealand scientists are world leaders in drilling for ice cores in Antarctica, but the Tasman effort will be the first time deep ice core recovery has been attempted on a mainland glacier.

The West Coast's Franz Josef and Fox glaciers' ice records go back only 40 to 50 years because they are steeper and their ice flows faster.

In the east, the Tasman Glacier is at a higher altitude, which means ice melts slower, is retained longer, and has a slower flow.

- NZPA