Apr 03, 2020 13:15:00

Evidence for the existence of tropical rainforests in ancient Antarctica, surprising discoveries such as plants growing in the dark

We know that the ancient Earth is a completely different environment, but new research has revealed that tropical forests once existed in Antarctica. At that time, despite the special environment of Antarctica, where day and night would continue for a long time, plants were growing at that time.

Temperate rainforests near the South Pole during peak Cretaceous warmth | Nature

https://www.nature.com/articles/s41586-020-2148-5

Evidence of ancient rainforests found in Antarctica-CNN
https://edition.cnn.com/2020/04/01/world/antarctica-ancient-rainforest-scn/index.html

Scientists Have Unearthed Traces of an Ancient Rainforest In ... Antarctica
https://www.sciencealert.com/discovery-of-ancient-rainforest-in-antarctica-is-a-grim-warning-of-earth-s-future

From February to March 2017, Johann Krages, a geologist at the Alfred Wegener Polar Ocean Research Institute in Germany, collected samples from the sea floor of the Amundsen Sea, Antarctica. According to a CT scan of this sediment core, forest soil, pollen, spores, roots, etc. were found in a state that was good enough to analyze the cell structure. This is the first time pollen has been found in a seed plant near Antarctica. Researchers also analyzed the soil and found that it was 90 million years old.

A map around Antarctica 90 million years ago looks like this. The red cross is where the sample was taken.

'When we first evaluated the sample on board the ship, we noticed that the layers of sediment were unfamiliar shades. 'We found a layer that was originally on the continent, not the ocean.'

The ancient earth is much warmer than today, and the

Cretaceous , 80 million to 115 million years ago, is said to be the warmest in the history of the earth. On the other hand, what kind of environment was near Antarctic at that time was not clear from previous studies. The sample collected in this survey is the southernmost sample that shows the state of Antarctica between 83 and 93 million years ago.

`` It's also surprising that a sample of a forest 9000 years ago was found in good condition, but it was understood from there, '' said Tina van Defriart, Professor of Earth Science and Engineering at Imperial College London, co-author of the study The content was surprising: even during months of darkness, the rainforests of the swamps near Antarctica were growing, showing that the climate was warmer than we expected. Ta '.

According to researchers, investigating the climatic conditions in which the progeny of the plants contained in the sample live, it was shown that there was no ice cap in western Antarctica and it was a rainforest swamp. The Antarctic at that time had a daytime temperature of about 11.6 degrees Celsius, which was extremely warm compared to -60 to 23 degrees Celsius in 2020. There is no ice sheet, and the temperature of the swamp is about 20 degrees. Precipitation is estimated to have been around 2.4 meters per year.

Researchers have speculated that the Antarctic continent at the time was similar to modern islands south of New Zealand.

Researchers have also found that carbon dioxide levels at that time were higher than existing climate models. Researchers believe that two factors, high carbon dioxide levels and a continent without ice sheets, created an optimal environment for tropical rainforests because carbon dioxide creates a warming effect by trapping heat from the sun. You.

On the other hand, it has not yet been clarified how Antarctica has been cooled enough to form an ice sheet, after turning from such a temperate climate.