The Australian Antarctic Division is preparing for what it says will be its most ambitious expedition season, as it chases the world’s first million-year-old ice core sample.
The project is a decade in the making, and will involve sending 500 scientists and support personnel south from Hobart in the next five months.
Chief scientist Nicole Webster said the project would provide an insight into past changes to climate and what might happen in the future.
“Layers in the ice core are essentially like pages in a diary,” Dr Webster said.
“Being able to open a window a million years into the past, we’re not just going to capture that point a million years ago, we will actually have the whole ice core to reconstruct past climate.
“We can model those changes we are seeing throughout the ice core to then predict what might occur into the future.”
Currently, the oldest drilled ice core is 800,000 years old.
Taking a trip into the past
The record-shattering ice core will be drilled 1,200 kilometres inland from Casey Station at a place called Little Dome C, 3,200 metres above sea level.
“At that site we expect the ice to be about 2.8 kilometres thick,” Dr Webster said.
“The Antarctic ice cap is actually formed by layers of snow deposited over time — these get compressed into ice.”
About 800 tonnes of cargo will travel from Hobart to Antarctica over the coming months to prepare for the drilling.
That includes tractors, vans and accommodation for the researchers, as well as the drill itself, which is 10 metres long and weighs 200 kilograms.
“Once the drilling actually starts, the teams will be working eight-hour shifts at about -30 degrees,” Dr Webster said.
The drill will break off three-metre pieces of ice at a time, sending it to the surface where scientists will unpack it, before heading back down to continue drilling.
Dr Webster said a successful season would result in about 1 kilometre of ice being drilled.
“That kilometre of ice will weigh somewhere between 6-8 tonnes and then needs to be transported back to labs in Hobart for that atmospheric gas analysis,” she said.
She said it would take expeditioners around five years to produce the full ice core.
“They’ll then compare their results with other teams from around the world, who are also working on this massive international project.”
Long-standing mystery could be solved
The million-year-old ice core will help scientists understand past and future climates.
“Things like past temperature, the frequency and intensity of volcanic eruptions, wind patterns, sea ice extent, dust … all of this information gets trapped in the ice core,” Dr Webster said.
And it could help solve a long-standing Antarctic mystery.
“Around 1 million years ago we saw a change in the periodicity of ice ages,” she said.
“We used to see one ice age occur every 41,000 years. Around a million years ago this changed to one ice age every 100,000 years.
“Currently we have no understanding of why this occurred.”
New ice breaker en route
The Australian Antarctic Division is also preparing for the arrival of its new icebreaker, the RSV Nuyina.
The division’s director, Kim Ellis, said the ship would arrive in Hobart next month.
“The Nuyina is in her final stages of a 23,000-kilometre delivery voyage, arriving in Hobart on the 16th of October,” he said.
“This ship brings a huge range of new capabilities for us.”Internet Explorer Channel Network