West Antarctica was ice-free 34 million years ago, new samples show

Today, few deny the impact of global warming. Now that the term has become slang for everything that is wrong with the planet, experts have been conducting empirical studies of its impact on the Antarctic ice sheets.

What used to be called “forever” is now melting rapidly, at a rate that was previously unimaginable. This is particularly the case in West Antarctica, much more so than in East Antarctica.

Recently, scientists have determined that the cause of the problem lies in the formation of ice.

In a new study, researchers report that the recovery of unique geological samples combined with advanced modeling has for the first time provided surprising insights into when and where the current Antarctic ice sheet formed.

The ice of West Antarctica formed 7 million years after the ice of East Antarctica.

An international research team led by the Alfred Wegener Institute discovered that permanent glaciation of the Antarctic ice was activated about 34 million years ago.

This was established by analyzing sediment samples from drill cores in combination with complex climate and ice sheet models.

Good Morning Johann, Senior Marine Geologist at the Alfred Wegener Institute, referred to the important discovery he told Interesting technique,

“West Antarctica began to permanently glaciate much later than East Antarctica—at least seven million years. So the dawn of Antarctic ice sheets reveals its fate.”

In a statement, the scientists noted that the ice age, which began 34 million years ago, did not cover the entire continent as previously believed, but was limited to the eastern part of the continent (East Antarctica).

However, new research has revealed why the ice in West Antarctica melted millions of years after the start of the ice age in the east.

Johann explained to I.E that it is crucial to know where permanent ice masses were located and to what extent they were present, in order for such fundamental climate changes as those that occurred about 34 million years ago to occur.

“That has a major impact on the circulation patterns in the atmosphere and the oceans,” he says.

“We now understand much better the last fundamental climate change from greenhouse to ice climate, almost 34 million years ago. It is essential to improve the predictive capabilities of climate models in general.”

Establishing the ‘history of the formation of the icy Antarctic continent’

When the Earth went through one of the largest climate transitions since the Eocene during the Paleogene, ice sheets formed in Antarctica.

As the team of scientists set out to piece together a timeline, they extracted a drill core using the MARUM-MeBo70 seafloor drilling rig, which is located offshore of the Pine Island and Thwaites glaciers on the Amundsen Sea coast of West Antarctica.

For the first time, a history of the dawn of the icy Antarctic continent has been established, the statement stressed. There was no evidence of the presence of ice in this region during the first major phase of the Antarctic glaciation.

“This means that a large-scale, permanent first ice age must have started somewhere in East Antarctica,” said Dr. Johann Klages, a geologist at the AWI who led the research team.

West Antarctica was ice-free during the First Glacial Maximum, but was surrounded by dense deciduous forests and a cool-temperate climate. This helped prevent ice from forming.

This is because West Antarctica remained ice-free during this first glacial maximum. At that time, it was still largely covered in dense deciduous forests and a cool-temperate climate that prevented ice from forming in West Antarctica.

When asked how the findings impact future changes in the Antarctic ice sheets, Johann told IE that it took much more effort to move stranded ice to the West Antarctic coast compared to East Antarctica, because many parts of West Antarctica were already below sea level.

“Much more of West Antarctica is now below sea level, so you would have to do a lot less to make the West Antarctic ice sheet disappear compared to its East Antarctic counterpart. This is where we are now.”

In short, East and West Antarctica respond differently to external forces and therefore ice formation occurred at different times.

Klages emphasizes the importance of understanding the findings, saying it is crucial “especially in light of the fact that we could face such fundamental climate change again in the near future.

The research was published earlier today [July 4, 2024] in the magazine – Science.