You will also be interested
[EN VIDÉO] Interview: is there a maximum temperature? Since there is a minimum temperature that represents the almost absolute immobility of atoms or molecules (-273.15°C), does the impossibility of exceeding the speed of light impose a maximum temperature? As part of its Expert Questions on Physics and Astrophysics video series, publisher De Boeck asked José-Philippe Pérez, professor emeritus at the University of Toulouse, to answer this question.
If the water temperature of the Atlantic Ocean varies on the surface according to the seasons and the latitude, the bottom remains at a constant temperature close to 0°C. In any case, this is currently the case, because a new study has just shown that 50 million years ago, the bottom of the Atlantic Ocean was warmer than the surface waters of the Mediterranean Sea!
Marine sediments: real time capsules
By drilling into the sediments of the ocean floor, researchers have been able to go back in time over 60 million years and follow the evolution of the temperature in this very special environment. Analysis of the chemical characteristics of shells small molluscs fossils present in the sediments has thus shown that the bottom of the Atlantic Ocean was once at an extreme temperature of 20°C!
The temperature of the water influences the construction shells of molluscs and in particular the way in which the atoms of carbon and oxygen are associated. This method seems to be particularly effective for understand how the climate has evolved over the past few million years.
CO levels2 three times higher than today
In the Eocene, the bottom of the North Atlantic was therefore at 20°C, 15 million years after the biological crisis who saw the dinosaurs disappear from the face of the earth. This period is associated with CO levels2 very high atmospheric values, about three times the current value. The earth’s climate was then very hot, in connection with the important greenhouse effect. Many fossils palm trees and crocodiles were also found in the polar region Arctic. This new study published in the journal Science shows that the continental surfaces are not the only ones to have suffered this extreme rise in temperatures, the bottom of the oceans has also been impacted.
In the context of global warming currently, this type of study is very important for better understand and anticipate the influence of CO2 on the climate and the temperature of the oceans.
Interested in what you just read?