Australian research to impact climate change predictions
Major climate events during past global ice ages did not happen simultaneously or with the same intensity world-wide,
new data from ANSTO’s latest climate change research has revealed. The research, which used sophisticated nuclear dating
techniques on rocks from Mongolian glaciers, could impact future climate change forecasts.
Reported in the latest edition of Velocity, the research for the first time 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.
Dr 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, scientifically termed ‘cosmogenic radioisotopes’, produced in
rock surfaces when they are freshly exposed after glaciers retreat to cosmic rays coming from the sun and outside the
solῡr system. 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.”
Dr Henrik Rother, the ANSTO post-doctoral research scientist who recently went to Mongolia for the second time to bring
back rock samples, explained that glaciers are sensitive climate change indicators.
“The expansion or retreat of mountain glaciers mirrors changes in temperature or precipitation and glacial records are
therefore extremely useful to help scientists reconstruct past climates and to date there was little dating information
on how the glaciers responded in central Asia,” he said.
“Because central Asian mountain regions are so remote and landlocked, we wanted to test how past climate changes
affected these regions and whether or not this was similar to other parts of the globe.
“At ANSTO dating rocks and deposits from glacial moraines is providing basic research to help improve models of past
climate variability which aims at improving predictions of future climate change which will be different over various
parts of the globe,” he said.
The research was made possible through collaboration with German Professor Frank Lehmkuhl, a world leader in climate
change research in central Asia from the University of Aachen. The idea was first conceived at a scientific meeting in
Tibet in China when Professor Lehmkul expressed an interest in ANSTO’s dating techniques. Dr. Rother was then invited to
join the first Mongolian expedition in 2007.
ENDS