90 million years ago, West Antarctica was a vast rain forest

Scientists say most of the western part of Antarctica and large areas of East Antarctica were once rain forests.

Antarctic rainforest illustration.

The land now icy and vacant year round was once inhabited by countless species of plants 90 million years ago. The climate was extremely warm at that time.

It was in the middle of the Cretaceous, when the sea level was now about 168 meters higher and the water temperature was about 35 ^° C. Professor Ulrich Salzmann of Northumbria University, UK - the co-author of the study - said the The immense lands in Antarctica were then humid lowland forests in the temperate zone. This type of forest covers most of the coast of Antarctica and may occupy most of the western part of Antarctica today.

Scientists use the Polarstern research icebreaker from Germany.

'It is hard to say what kind of trees grow on higher land in the mountains, because we don't have data on this area yet. However, the climate model we use shows that much of Antarctica's area has certainly been trees and there is no permanent ice cover as it is now, '' Professor Ulrich Salzmann said.

The first evidence of the existence of the Antarctic rainforest is a sedimentary core discovered in 2017. The sediment core was taken from the seabed near the Pine Island glacier in the West Antarctic. 'During the preliminary survey trip, the unusual color of the sediment caught our attention, it was different from the upper layers' - Dr. Johann Klages, geologist of the Alfred Wegener Institute, team member research said.

"At a depth of 27 - 30 meters below the sea floor, we found a layer whose origin was originally formed on the ground, not in the sea."

This map shows the location of the bores and the locations of the continents 90 million years ago.

A technician is remotely controlling the seabed drilling system called the MeBo of Polarstern.

The team took this core and discovered a network of tree roots in the soil layer. This soil layer dates back 90 million years and contains countless traces of pollen, spores and corpses of flowering plants. The researchers said the traces were incredibly well preserved, and that they were able to find the cellular structure of each specimen. These specimens show that the West Antarctic coast was then a dense, temperate, swamp forest, much like today's New Zealand forests.

Professor Tina van de Flierdt and Dr. Johann Klages are studying ancient soil samples.

Scientists have found evidence that a large region about 804 km south of the Earth's south pole used to have a pleasant climate with an annual average air temperature of about 12 ⁰ C, while the average temperature entering summer is 19 ⁰ C and the temperature of river water and swamp is 20 ⁰ C. Rainfall here is equivalent to the rainfall of Wales, England, today.

This research has been published in the journal Nature.

1. Discover traces of ancient continent in Antarctica
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