‘Colder and deeper’: Scientists shut down space to drill 1.5m-year-old Antarctic ice core | Environment

Antarctic scientists are nearing the end of a drilling space deep inside the frozen continent that could reveal a continuous record of the Earth’s climate dating back 1.5 million years.

After nearly a decade of work, scientists at the Australian Antarctic Region are nearly marking a location for drilling an ice core nearly 3,000-meters deep.

A successful mission would provide scientists with a reliable record of Earth’s ancient climate that would be half a million years or older than conventional ice records.

The site has an average daily temperature of -51C (-60F), known as Little Dome C, which is about 1,100km inland from the Casey research center in Australia.

In the continent’s ancient ice, air bubbles have been captured and sealed over thousands of years that act as tiny capsules of the Earth’s atmospheric state.

Ice cores have been a key tool for global climate scientists to understand what has happened to Earth’s climate in the past and what might have happened in the past. future as greenhouse gas levels from fossil fuel burning go up.

The area around Little Dome C is about 40 kilometers away from Dome C – also known as Dome Concordia – which is the site of the longest continuous ice sheet to date, dating back about 800,000 years.

A European-backed effort that has already worked closely with the Australian team has already identified a drill site in the same Little Dome C area.

Dr. Joel Pedro, an expert on ancient climate, is a lead project scientist at the Australian Antarctic Region’s Million Year Ice Core Project.

He said the selection of the site would be the result of nearly a decade of work.

“We haven’t thrown the spear yet and we’re doing model work,” he told the Guardian. “We have it down to within four or five kilometers and we will upgrade it within the next few months before we make a decision and a commitment.”

Pedro said it was hoped that pilot drill work would begin near the end of 2021, but that some supply challenges could delay efforts.

Said Pedro. “We push the boundaries of technology for our measurement, and our drill, and our ability to get out. ”

Scientists say the area, where the average daily temperature is -51C (-60F), will require several drilling summers to get to the oldest ice.

Scientists say the area, where the average daily temperature is -51C (-60F), will require several drilling summers to get to the oldest ice.

Approximately 300 tonnes of equipment has to be transported to the site, which is approximately 3,000 meters above sea level. A drill will try to drive down about 2,800 meters to get to the oldest ice which is estimated to be between 1.2m and 1.5m years old.

Getting to the oldest ice will require several drill summers, with one three-meter section taking two hours to recover when the drill approaches the deepest limits.

At the deepest sections of it, Pedro said about 14,000 years of snow is compacted into every ice meter.

Ice as old as 2.7m years ago was recovered from Antarctica, but this ice did not come from a continuous ice core, leaving long data gaps.

Extending the ice’s core plateau from 800,000 years to 1.5m would reveal how the fusion of the atmosphere changed at a time known as the Central Pleistocene Transition (MPT) as it moved. the period between ice ages from 41,000 years to 100,000 years.

Pedro said it is an open question right now about why the Earth’s ice cycles moved. But the ice core would reveal “basic information about it [the Earth’s] sensitivity to CO2. “

Old ice, future climate models

Professor Carlo Barbante, who is coordinating the European effort, said in partnership with researchers from Australia and the US, that more than 4,000 kilometers of radar measurements were taken from planes and planes. take the land as part of the research.

The old ice had accumulated in the area due to very low snowfall, extremely cold temperatures, and little heat coming from the bedrock below.

Barbante, from the Italian Institute of Polar Sciences, said that understanding what happened during the MPTs “has a profound effect on today’s climate and in particular on the sensitivity of our planet to the changes in CO2 concentrations. ”

He described the changes in the cycles of the ice ages as “one of the most enigmatic puzzles in the climate system” and “answering why it happened” would greatly improve our understanding of how in which the climate system works. ”

He said: “This is critical to more reliably predicting the future of our climate, beyond the next few decades, beyond 2100, in order to understand the long-term effects on civilization and humanity are our current fossil fuel burning activities. ”

Pedro said that in addition to showing the levels of greenhouse gases in the atmosphere and how they changed, the analysis would also look for other gases – xenon and krypton – that can be studied to estimate temperature the ocean.

A parallel European effort was important, Pedro said, because it would allow comparisons of results and give scientists more confidence in their results.

Pedro is slated to be part of the team that will be sent to the site. He had previously worked on Antarctica and it is similar to the conditions for experiencing a “completely new force of nature”.

The situation at Little Dome C would be “cold as hell,” he said. “People have compared this to doing science in space. ”

Dr David Etheridge, a climate scientist at CSIRO, has carried out a number of pole drilling projects, but said the conditions at Little Dome C would be “harder, colder and deeper” than previous efforts.

He said the prospects for a 1.5m-year-old ice core were a major human challenge, but that it would provide vital knowledge to develop global climate models.

Pedro updated the Australian climate science community on the ice core project in a presentation Friday at the Australian Weather and Marine Science Association’s annual conference, which was almost held.