Since its creation and then the emergence of life, planet Earth has experienced many cataclysms. About 13,000 years ago, for instance, a firestorm swept across nearly a tenth of the Earth's surface. However, researchers believe this catastrophe could rival in gravity the catastrophe generated by the asteroid that wiped out the dinosaurs.
When we think of the cataclysms that have devastated the Earth, the asteroid that caused the Chicxulub crater often comes first. The object, 14 kilometres wide, crashed into the Earth 66 million years ago and caused a mass extinction event which ended the reign of the dinosaurs. The collision caused massive forest fires, hurricanes, earthquakes and landslides. Scientists recently estimated that the asteroid also caused a tsunami with waves up to 1,500 metres high.
However, a February 7, 2022 article published in Science Alert told of a different cataclysm. This one occurred much closer in time to us: about 13,000 years ago. The Earth was engulfed in a firestorm over almost a tenth of its surface. A team from the University of Kansas (USA) published a study on the subject in 2018. According to the researchers, the most likely hypothesis is that a large comet underwent a breakup during its arrival. Various fragments then collided with Earth and caused a catastrophe.
The effects of this firestorm can be compared to those of the asteroid Chicxulub. The gigantic fires created huge clouds of dust which engulfed the Earth. Our planet then entered a 1200-year ice age, when it had just emerged from a 100 000 year ice age. After the fires disappeared, life was able to resume.
In 2018, the 84 scientists involved in the study measured numerous geochemical and isotopic markers at no fewer than 170 locations around the world. The goal? To reconstruct the history of this grand firestorm. These markers, which include carbon dioxide, nitrate and ammonia, made it possible to assess damage over an area of 10 million km², just under a tenth of the Earth's surface.
Known as the Late Dryas (see chronology), the 1200-year ice age represents the last cold oscillation of the last ice age. However, this variation remained unexplained until the work of American firestorm researchers. Nevertheless, it must be remembered that the hypothesis of a comet break-up, whose fragments produced the storm, is not new and has still not been unanimously accepted by the scientific community for decades.
