A geological phenomenon widens the Atlantic Ocean …

A survey published in the journal Nature states that the plaques attached to the Americas are moving away from those linked to Europe and Africa at the rate of four centimeters per year.

“There is an increasing distance between North America and Europe, and it is not driven by political or philosophical differences, it is caused by mantle convection!”, Underlined Dr Nick Harmon of the University of Southampton, one of the researchers who participated in the research.

Between these continents is the Mid-Atlantic Ridge, a divergent boundary between tectonic plates that stretches across the Atlantic Ocean. In the North Atlantic, it separates the Eurasian and North American plates, while in the South Atlantic, it separates the African and South American plates. There, a new oceanic crust is formed by volcanic activity and the gradual movement of the bottom away from the ridge.

Now a team of seismologists from the University of Southampton, in the UK, found evidence of upwelling in the mantle, the material between the earth’s crust and its core, at depths of more than 600 kilometers below the Mid-Atlantic mountain range.

The results provide a better understanding of the plate tectonics that causes many natural disasters around the world, including earthquakes, tsunamis and volcanic eruptions.

The investigation

The team deployed 39 seismometers on the Atlantic floor as part of the PI-LAB (Passive Imaging of the Lithosphere-Asthenosphere Boundary) and EURO-LAB (Experiment to Unearth the Lithosphere-Asthenosphere Ocean Rheological Boundary) experiment. He did this on research cruises aboard ships. RV Langseth Yes RRV Discovery.

The data provides the first large-scale, high-resolution image of the mantle under the Mid-Atlantic Ridge. This experiment, one of the few carried out in large-scale oceans, allowed the team to image variations in the structure of the Earth’s mantle at depths of 410 km and 660 km, associated with abrupt changes in phases. mineral.

Matthew Agius, former postdoctoral fellow at the University of Southampton and currently at Università degli studi Roma Tre, said that “it was a memorable mission that took us in total 10 weeks at sea in the middle of the Atlantic Ocean . The incredible results shed new light on our understanding of how the Earth’s interior is connected to plate tectonics, with observations never before seen. “

Dr Kate Rychert and Dr Nick Harmon from the University of Southampton and Professor Mike Kendall from the University of Oxford led the experiment. Harmon noted that “there is an increasing distance between North America and Europe, and it is not driven by political or philosophical differences, it is caused by mantle convection!”

In addition to helping scientists develop better models and warning systems for natural disasters, plate tectonics also impacts sea level and therefore affects estimates of climate change at geological time scales. .

“It was completely unexpected,” said Rychert. “This has broad implications for our understanding of Earth’s evolution and habitability. It also shows how crucial it is to collect new data on the oceans. There is much more to explore!”

For her part, Kendall noted that “this work is exciting and refutes long-held assumptions that mid-ocean ridges may play a passive role in plate tectonics. This suggests that in places like the mid-Atlantic, the forces on the ridge play an important role in the separation of the newly formed plates. “