Tectonic plates drive ocean oxygenation – Rising thanks to that?

news7g08/18/2022

4 1 minute read

Tectonic plates drive ocean oxygenation - Rising thanks to that?

CNRS

Dark sediments, rich in organic matter, indicate low ocean oxygen conditions, located between layers of limestone. — **IMAGE: ORGANIC RICH, DARK BED INDICATIONS LOW KITCHEN, BETWEEN LIMESTONE BED.** see more CREDIT: © CHRISTOPHE THOMAZO

Until now, it was thought that the oxidation of the oceans over geologic timescales was mainly driven by atmospheric oxygen levels. However, a new study published in Nature on June 27, 2022 suggests otherwise. Research by scientists at the Laboratory of Biological Sciences (CNRS/UBFC), along with their colleagues in the University of California’s Department of Earth and Planetary Sciences, reveals the motion of the plates Tectonics probably contributed to ocean oxygenation. To demonstrate this, the scientists used a three-dimensional climate model to reconstruct conditions on Earth from 540 million years ago to the present day, specifically taking into account oceanic circulation currents. positive. In their model, the scientists modified the positions of the continents while keeping the concentration of oxygen in the atmosphere constant. As a result, the concentration of oxygen in the oceans increased, although the amount of oxygen in the atmosphere remained constant. Thus, the new paper shows for the first time that oxygen concentrations in the atmosphere and ocean are largely independent of each other. As oxygen is so important to marine life, these findings suggest a hitherto underappreciated role of plate tectonics in the evolution of biodiversity in the ocean across geologic time scales. matter.