TRANSCRIPT
In remote East Antarctica, scientists drill through five metres of thick ice.
It's an hour before they penetrate through to the water below.
The next phase is carried out by hand.
Geophysicist Dr Coti Manassero and a glaciologist Dr Sarah Thompson deploy hundreds of metres of rope into the icy waters to explore what lies beneath.
Dr Manassero says the team were surprised to discover this underwater canyon is at least 1200 metres deep.
And a camera - attached to the rope - revealed something else unexpected.
"And we also were very surprised to find some life down there. Some sponges, some brittle stars. The mining ecologies are very excited about that because they didn't expect to see anything.I think it proves the point of how little we know about this region."
This part of Antarctica - five-thousand kilometres south of Australia - is home to the Denman glacier, which is melting fast.
Research suggests it's retreated more than five kilometres over the past two decades.
Underneath the glacier lies what scientists have modelled as Earth's deepest land canyon, stretching three-point-five kilometres below sea level.
Dr Thompson says the vast trough could contain so much ice that if were to melt completely, it could raise global sea levels by 1.5 metres.
"Because it is such a big system and a complex system, we really don't have a good handle on the kind of timescales over which that kind of change could happen. So it's really important that we find out a lot more about the system to allow us to better predict the changes and the impacts of those changes that we might see."
The team have drilled into what's known as an epi-shelf lake - a type of lake that forms when freshwater from melting glaciers is trapped above denser, saltier water from ice shelves.
Dr Thompson says the lakes provide a unique opportunity to study areas of the ocean that are typically challenging to access.
"In East Antarctica we've realised that the main place that the ice is changing is at the interface between the ice shelf and the ocean. So here we're looking at how changes in ocean temperature affect the melting of the ice shelves at the bottom, and this mooring will give us a really good indication about the properties of the ocean that can reach the point at which the ice starts to float."
She says as well as the camera, instruments to measure the water's temperature, salinity and depth, were also deployed.
The mooring will stay in place for two to three years and transmit data back to Australia.
It's just one project among a series carried out over the past three summers as part of a major science campaign by the Australian Antarctic Division.
The deep-field program- studying the history and stability of the Denman Glacier - is wrapping.
But the science is just beginning.
The data and discoveries, including tonnes of rock and ice core samples are being sent to labs across Australia, to be analysed for years to come.
