Ready to listen as Antarctic reveals secrets
Funding will help us understand how the icy continent is changing, writes
Underneath the surface of the Antarctic, there is a seismic symphony at play. Glaciers are grinding, crevasses are splitting ice apart, icebergs are calving and melt water is percolating into and beneath the ice sheet.
For the next two years, my team and I will make seismic recordings of that symphony, on location in key glacier systems of the Antarctic, to understand what it is telling us.
Our research group at the University of Tasmania has recently been awarded Geophysical Research Infrastructure for Antarctica (GRIT) funding of $4.9m to achieve this, and are planning to go to the southernmost continent on Earth in partnership with the Australian Antarctic Division.
The funding will enable us to purchase, assemble and install specialist, polar-rated instruments, as well as contribute to the field logistics necessary – aircraft, fuel, helicopters and day-to-day living requirements – for a summer on the ice.
Achieving the GRIT funding is a big step up from the “normal” methods of science finance and scientists being funded in smaller increments.
It will enable our team to record an initial set of data and then, over the next few years, build important datasets for Australia as a nation.
One of our primary endeavours is to achieve a baseline understanding of how the major glaciers are moving in East Antarctica – what the ice sheets are actually doing.
Part of the excitement is bringing the different lines of evidence together to solve the puzzle of how the Antarctic continent is changing
Our seismic sensors will discover the extent of the many types of icequakes within the Antarctic region, and monitor how that symphony of icequakes changes over time.
We want to understand the changes in the glaciers’ progress, as the glaciers head to the ocean.
We place our instruments at the mouths of the important outlets and track whether the glacier is sliding or cracking more than the previous year.
At the moment, all eyes are on Greenland in the Arctic, which appears to be ahead of Antarctica with regards to major glaciers retreating and the ice sheet melting.
As Antarctica holds a much greater volume of ice than Greenland, we want to be prepared with instruments in place as new parts of Antarctica start changing.
Ice quakes tell scientists about the hidden processes and how quickly they are happening.
For example, one might monitor a “melt lake” on the ice from a satellite
– but the next time the satellite passes overhead, the melt lake has gone. Where has it gone?
If the water from the melt has gone into the base of the glacier, it can lubricate it to go faster – and the ice to move faster into the ocean.
We can do this extremely accurately because our seismic sensors record hundreds of times each second.
So much of what scientists do is hard work behind the scenes. We must apply for separate grant funding to process the data that we collect.
This enables group members to adapt computer programs that were originally designed for earthquake data to the new challenge of
analysing icequake data.
The GRIT funding will also purchase other types of instruments.
These include super-accurate GPS receivers that track whether the continent is being weighed down by new snow or is rising up as the ice sheet is lost.
Other instruments use natural fluctuations in the Earth’s magnetic field to highlight electrically conductive patches beneath the ice, that could indicate even deeper groundwater.
Part of the excitement is bringing the different lines of evidence together to solve the puzzle of how the Antarctic continent is changing.
My next field season will be my 10th time in the Antarctic. What our team hopes to achieve for Australia as a nation is a true record of change, and custodianship of information that reveals what is going on with the ice sheet – above and below the surface of the Antarctic.
Because what is happening affects the world in terms of global sea levels rising, as a response to the changing climate.