It has been nearly two years since my expedition to Mackay Glacier in the Transantarctic Mountains. Following a lot of lab work, data processing, numerical modelling and manuscript writing, the results have now been published!
To quote Victoria University of Wellington’s media release:
By studying rocks at different elevations beside the East Antarctic Ice Sheet (EAIS), the team concluded that a period of rapid glacier thinning occurred in the recent geological past, and persisted for several centuries.
Satellite observations show that parts of the Antarctic ice sheet are currently thinning in response to a warming ocean. Of particular concern is the potential for ‘marine ice sheet instability’, where an initial retreat of ice margins into deepening valleys could lead to continued, unstable ice loss.
The new research, led by Victoria Postdoctoral Research Fellow Dr Richard Jones, indicates that the processes leading to instability can be initiated by just minor climate warming.
“The finding is very important for predicting Antarctica’s future contribution to sea level change,” says Dr Jones. “Particularly when considering that the EAIS contains enough vulnerable ice to raise sea level by tens of metres.
“It might only require a small amount of climate variation to initiate runaway ice loss, and it could continue for centuries to millennia,” says Dr Jones.
While this process has been posited for many years, the study presents the first directly recorded evidence that it has taken place in the past, providing new insight into the future behaviour of rapidly changing parts of Antarctica today.
A major strength of the study was combining numerical modelling experiments that simulate glacier retreat with geological data processed in Victoria University’s world-class cosmogenic nuclide laboratory.
The laboratory studies rare isotopes produced through the interaction of cosmic radiation with minerals on the Earth’s surface, which allows for the calculation of the age of a rock surface.
“Most research has previously focused on the West Antarctic Ice Sheet, which makes these observations from East Antarctica all the more significant,” says Dr Jones.
Dr Jones’ research has been published in the journal Nature Communications.
The field work and data collection conducted as part of this study were captured in a video and can be viewed at https://vimeo.com/80447422.
Stories on the new findings were written by the New Zealand Herald, and Radio New Zealand, featuring live and recorded interviews.
In less than one month, I’ll be heading down to Antarctica again. This time our team will be visiting a larger glacier, in order to better understand the response of such glaciers to a warming climate and these ‘marine ice sheet instability’ feedbacks during the last major deglaciation.
More blog updates to follow shortly. Watch this space.