Climate change during ice age did not happen at once

December 10th, 2008 - 2:28 pm ICT by IANS  

Sydney, Dec 10 (IANS) Major climatic events during past global ice ages did not occur at once or with the same intensity everywhere, according to new data. The research by Australian Nuclear Science and Technology Organisation’s (ANSTO), which used sophisticated nuclear dating techniques on rocks from Mongolian glaciers, could impact future climate change forecasts.

The research shows that Mongolian glacier advances during the last ice age were not synchronised with alpine glaciers in Europe and North America, suggesting that climate varied significantly between continents.

David Fink, Leader of ANSTO’s Cosmogenic climate Archives of the Southern Hemisphere (CcASH) project, said ANSTO has refined a dating technique which measures nuclear signals or ‘cosmogenic radioisotopes’, produced in rock surfaces when they are freshly exposed. This technique can accurately date the time glaciers advance and retreat.

“The method is quite unique and the build-up of long-lived radioisotopes called Beryllium-10 and Aluminium-26 to date glacially transported rocks is now opening new doors to providing high resolution climate records from mountain regions around the world,” he said.

“By ‘counting’ the atoms using Acceleratory Mass Spectrometry we can, for the first time, date the geological event that exposed the rocks to cosmic rays and from that establish a chronology of past glaciations going back as far as three to four million years and as short as a few thousand,” he said.

“We are also applying the same technique to measure the glacial episodes in Tasmania and New Zealand over the last 100,000 years,” he said, according to ANSTO release.

Henrik Rother, ANSTO scientist who recently went to Mongolia for the second time to bring back rock samples, explained that glaciers are sensitive climate change indicators.

These findings appeared in the latest edition of Velocity.

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