Venu Menon
Wellington, February17,2024
The West Antarctic Ice Sheet has yielded groundbreaking scientific data hidden deep underneath its mass that sheds new light on climate warming, scientists say.
For the past three months, a 27-member team of scientists, drillers, and crew have set up camp at a drilling site 860 km from Scott Base, New Zealand’s Antarctic research station.
They are part of the SWAIS2C (Sensitivity of the West Antarctic Ice Sheet to 2 degrees Centigrade of Warming) project. Their mission is to drill through layers of sediment hidden under the ice sheet at depths of up to 200m below the ocean floor.
Their objective is to obtain geological data going back hundreds of thousands of years, “potentially even millions of years,” that is crucial to our understanding of climate warming,
Such a record would include the last interglacial period 125,000 years ago, when Earth was around 1.5 degrees Centigrade warmer than pre-industrial temperatures – similar to the temperatures we are approaching this year due to climate change, according to a statement released by Victoria University of Wellington.
“We’re at the frontier, drilling through an ice shelf into the sea floor, to acquire sediment samples that no one has previously been able to obtain,” says Prof Richard Levy, SWAIS2C co-chief scientist from GNS Science and Victoria University of Wellington.
The information retrieved from beneath the Antarctic ice shelf will “allow us to build a much better picture of how Antarctic ice will respond to future warming, which parts will melt first, and which parts will remain,” Prof Levy points out.
The scientific team, co-led by GNS Science, Victoria University of Wellington, and Antarctica New Zealand, successfully drilled through 580m of ice, and scooped up sediment that contained a history of how the West Antarctic Ice Sheet has responded to climate warming in the past.
To retrieve sediment hidden 200m below the ocean floor required a custom-designed drilling system, known as the Antarctic Intermediate Depth Drill (AIDD).
The drilling system used by SWAIS2C was designed and constructed in Porirua by staff from Victoria University of Wellington’s Antarctic Research Centre and Webster Drilling and Exploration.
The prehistoric layer of mud and rock that stored the vital scientific clues lay blocked by a 580m thick wall of impenetrable ice above it.
The team used hot water to drill through the ice, melting it down to get to the sediment core.
But operations were called off in the face of “technical challenges.”
Drilling will resume at the site next summer.
“This year we got tantalisingly close. With the knowledge we’ve gained from the samples collected over the technological experiments conducted, we have an excellent chance next year to recover the long sediment cores to provide the climate insights we’re chasing,” Prof Levy notes.
He says the samples “help us understand the present-day environment beneath the ice shelf and the history those sediments represent.”
The samples will also provide insight into the microorganisms “living in the unique cold and dark environment.”
The ocean cavity, which lies between and separates the sediments and the ice shelf above, is itself a repository of oceanographic data such as salinity, temperature, and density in the ocean. Instruments were deployed to collect data on ocean currents and other information.
Scientists are preparing for the next leg of the exploration next year.
Says Prof Tina van de Flierdt, SWAIS2C co-chief scientist from Imperial College, London, “We are thrilled with what we’ve achieved. It’s a massive step forward towards our ultimate goal to recover the sediment we need to answer the big questions that are crucial for humanity as we adapt and plan for sea-level rise.”
Venu Menon is an Indian Newslink reporter based in Wellington
