The otherworldly continent of Antarctica down south—way down south—has been known as “the final frontier” for decades, and has captured the fascination and imagination of peoples since it was first spotted by explorers back in 1820. And while the detrimental effects of human-induced climate change is causing the emergence of huge concern over the future of Antarctica—like how losing its surface ice may be causing the Earth’s crust to “warp”—it nevertheless has remained an ice-capped landmass since humans had first laid eyes on its shores.
With a name that quite literally means “opposite the Arctic” in Romanized Greek, Antarctica is actually the fifth largest continent, sitting at nearly double the size of Australia. Some 98% of its surface area is covered by ice that averages at about 1.9 km thick—which also makes Antarctica the continent with the highest average elevation.
Now, most of you surely must have heard of the concept of plate tectonics, which is a theory that explains how Earth’s surface features—like continents—are shaped by our planet’s subterranean movements. It may not come as a surprise to most of you, then, that Antarctica wasn’t always down south. In fact, Antarctica used to be part of the supercontinent Gondwana, a giant landmass that existed since the Neoproterozoic Era; this supercontinent eventually broke away from the supercontinent Pangaea during the Cretaceous Period.
Rtecent models and geological studies have shown that Antarctica started freezing over some 40 million years ago after it broke apart from what was to become Australia and New Guinea. From there, Antarctica encountered changes in surrounding ocean currents accompanied by its slow downward drift away from the Equator, the effects of which grew the ice over its once-lush lands. The Pleistocene Ice Age finally covered the entirety of Antarctica with ice; the continent has remained a polar desert ever since. (Subsequent ice ages would end up hitting human populations then, too; read more about your ancestors’ fate here.)
It’s obvious, then, that Antarctica then would have been incomparable to the features—or lack thereof—seen in Antarctica today. This statement may have never been more applicable than it is now, with new research led by Federal University of Pernambuco paleobiologist Flaviana Jorge de Lima and published in the journal Polar Research. In fact, it couldn’t be further from its current state; apparently, 75 million years ago, Antarctica was on fire.
The time frame of 75 million years ago places Antarctica in its state some 10 million years before the end of the Age of Dinosaurs, somewhere in the Cretaceous Period. Back then, Antarctica was still covered in lush jungles, and was still part of the supercontinent Gondwana. It would have been home to several plants and trees, as well as dinosaurs and mammals.
De Lima and team actually found evidence for this “fiery” Antarctic landscape on James Ross Island, an island near the tip of the Antarctic peninsula. There, they obtained fragments of fossilized plants that suspiciously looked like charcoal residue back during a 2015-2016 expedition.
These charcoal fossil fragments were very small, with some barely reaching sizes of 38 mm (1.5 in) on one side. Once examined under a scanning electron microscope, experts now believe the fossilized plant to be a member of the plant family Araucariaceae, and were burned gymnosperm plants.
“This discovery expands the knowledge about the occurrence of vegetation fires during the Cretaceous, showing that such episodes were more common than previously imagined,” de Lima said in a statement to news source LiveScience.
As the study itself wrote out: “Antarctica had intense volcanic activity caused by tectonics during the Cretaceous, as suggested by the presence of fossil remains in strata related to ash falls. It is plausible that volcanic activity ignited the paleo-wildfire that created the charcoal reported here.”
This is not the first time a discovery of this kind was documented; several signs of ancient life, including dinosaurs and flowering plants, had been found there before. What stands out for this research, however, is how the evidence of 75-million-year-old fires appeared in the last place you’d expect fires to take place.
Nevertheless, de Lima and team are busy looking for geological traces of other ancient fires in locations across Antarctica. In doing so, the team hopes to gain a better understanding of all the events that came before that shaped the mysterious ice-enveloped continent.
References
- Bryner, J. (2017, December 13). Icy images: Antarctica will amaze you in incredible aerial views. LiveScience. https://www.livescience.com/60943-amazing-antarctica-photos.html
- Geggel, L. (2021, October 26). Wildfires burned Antarctica 75 million years ago, charcoal remnants reveal. LiveScience. https://www.livescience.com/ancient-wildfires-burned-antarctica
- Geggel, L. & LiveScience. (2021, October 27). Antarctica was on fire 75 million years ago, ancient embers reveal. ScienceAlert. https://www.sciencealert.com/scientists-discover-that-antarctica-was-on-fire-75-million-years-ago
- Lima, F. J. de, Sayão, J. M., Ponciano, L. C. M. de O., Weinschütz, L. C., Figueiredo, R. G., Rodrigues, T. M., Bantim, R. A. M., Saraiva, A. Á. F., Jasper, A., Uhl, D., & Kellner, A. W. A. (2021). Wildfires in the campanian of james ross island: A new macro-charcoal record for the antarctic peninsula. Polar Research, 40. https://doi.org/10.33265/polar.v40.5487
- Zimmermann, K. A. (2017, August 29). Pleistocene epoch: Facts about the last ice age. LiveScience. https://www.livescience.com/40311-pleistocene-epoch.html
