Of particular technical interest is the way the team - led by CSIRO's Dr Ron Thresher and comprising scientists from CSIRO, the Antarctic Climate and Ecosystems Cooperative Research Centre, the Woods Hole Oceanographic Institute and the California Institute of Technology - went about its work.
Drawing on microanalysis capability at CSIRO Minerals, Dr Thresher's team applied
an established (albeit continually improving) technology in a new way.
microanalysis work in marine applications about 15 years ago in response to what he
says was a dearth of historical information about the deep ocean.
could see the potential of microanalysis in helping create a picture of deep-water conditions going back centuries.
One of the objectives of Dr Thresher's
deep-sea coral research was simply to help 'calibrate' existing climate change models.
"People were building all sorts of complicated models showing how water mass distribution was going to vary as a result of climate change, but there was very little information to tell us whether these models were 'real' or accurate," Dr Thresher
"Without this sort of work, it's extremely difficult to tell whether the information we currently have relates to natural (climate) cycles, or whether it's the result of other factors."
By studying growth rings on coral collected off the south-east coast of Tasmania, the team was able to unlock details of water temperature and salinity level variations over the course of the corals' lifetime.
The corals were, in a sense, living time capsules, revealing to the team secrets from centuries past.
The first thing Dr Thresher's
work showed was that the corals were much longer-lived than previously thought, with some predating European settlement.
says this discovery has a bearing on the management of the coral reefs themselves: "Given its age, the coral isn't going to come back quickly if there's any damage done to it."
Perhaps more significantly, the work also shows there has been a one to one-and-a-half degree temperature change deep in the Southern Ocean over the past 400 years.
"This might not sound like much," Dr Thresher
says, "but when you consider that the temperature range at these depths (about 1000 metres) is only very small (from four to six degrees), what we're looking at is a very major change."
So, what does this tell us about global warming?
"Well we're still working on that," Dr Thresher
believes that studying corals from other parts of the world will give him a much clearer picture of what's going on.