Geological Phenomenon Widening the Atlantic Ocean
An upsurge of matter from deep beneath the Earth’s crust could be pushing the continents of North and South America further apart from Europe and Africa, new research has found.
The plates attached to the Americas are moving apart from those attached to Europe and Africa by four centimeters per year. In between these continents lies the Mid-Atlantic Ridge, a site where new plates are formed and a dividing line between plates moving to the west and those moving to the east; beneath this ridge, material rises to replace the space left by the plates as they move apart.
Conventional wisdom is that this process is normally driven by distant gravity forces as denser parts of the plates sink back into the Earth. However, the driving force behind the separation of the Atlantic plates has remained a mystery because the Atlantic ocean is not surrounded by dense, sinking plates.
Now a team of seismologists, led by the University of Southampton, have found evidence of an upwelling in the mantle — the material between the Earth’s crust and its core — from depths of more than 600 kilometers beneath the Mid Atlantic ridge, which could be pushing the plates from below, causing the continents to move further apart.
Upwellings beneath ridges are typically thought to originate from much shallower depths of around 60 km.
The findings, published in the journal Nature provide a greater understanding of plate tectonics which causes many natural disasters around the world, including earthquakes, tsunamis and volcanic eruptions.
Over two research cruises on the RV Langseth and RRV Discovery, the team deployed 39 seismometers at the bottom of the Atlantic as part of the PI-LAB (Passive Imaging of the Lithosphere-Asthenosphere Boundary) experiment and EURO-LAB (Experiment to Unearth the Rheological Oceanic Lithosphere-Asthenosphere Boundary). The data provides the first large scale and high-resolution imaging of the mantle beneath the Mid-Atlantic Ridge.
This is one of only a few experiments of this scale ever conducted in the oceans and allowed the team to image variations in the structure of the Earth’s mantle near depths of 410 km and 660 km — depths that are associated with abrupt changes in mineral phases. The observed signal was indicative of a deep, sluggish and unexpected upwelling from the deeper mantle.
Lead author, Matthew Agius, a former post-doctoral fellow at the University of Southampton and currently at Università degli studi Roma Tre said: “This was a memorable mission that took us a total of 10 weeks at sea in the middle of the Atlantic Ocean. The incredible results shed new light in our understanding of how the Earth interior is connected with plate tectonics, with observations not seen before.”
Dr. Kate Rychert and Dr. Nick Harmon from the University of Southampton and Professor Mike Kendall from the University of Oxford led the experiment and were the chief scientists on the cruises. The experiment was funded by NERC (Natural Environment Research Council, UK) and the ERC (European Research Council).
Dr. Harmon said: “There is a growing distance between North America and Europe, and it is not driven by political or philosophical differences — it is caused by mantle convection!”
As well as helping scientists to develop better models and warning systems for natural disasters, plate tectonics also has an impact on sea levels, and therefore affects climate change estimates over geologic times scales.
Dr. Rychert said: “This was completely unexpected. It has broad implications for our understanding of Earth’s evolution and habitability. It also demonstrates how crucial it is to gather new data from the oceans. There is so much more to explore!”
Professor Mike Kendall added: “This work is exciting and that it refutes long-held assumptions that mid-ocean ridges might play a passive role in plate tectonics. It suggests that in places such as the Mid-Atlantic, forces at the ridge play an important role in driving newly-formed plates apart.”
Reference: “A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge” by Matthew R. Agius, Catherine A. Rychert, Nicholas Harmon, Saikiran Tharimena and J.-Michael Kendall, 27 January 2021, Nature.
Funding: Natural Environment Research Council, European Research Council
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If the distance in the Atlantic is increasing, is the distance in the Pacific decreasing? If the continents were once one, could this eventually put the continents back together only the opposite way?
This is not a recent discovery! There are no “sinking” plates at the edges of the Atlantic, just look further afield to California and the American West coastal plates, and the Asian Ring of Fire. That’s where the corresponding movement is!
Like one of the guys above me commented this is not a new discovery this has been going on for the past 7-8 thosand years. Pangea was busted apart by a meteorite or multiple meteorites that struck the Pacific ocean side of the planet than cracked the Earth wide open and started the swirling currents under the crust in the mantle. The intense heat from the strike vaporized the majority of the ocean causing it to ran for 40 day and the water levels to rise in a tsunami that then took a year for the waters to recede this action and all the new currents created many multiple layers of new soil on the planet moving corpses of all kinds of creatures that once lived on it to almost everywhere but the center of the large continents. Due to the fact that earth was still so young and the majority of the layers of the earth where still soft, the swift and sudden movement and collision of some continents caused the formation of the Himalayan Mountain range. As well as the quick cooling of the then newly exposed ocean of maga that formed from the meteor strike as it was filled back up with the water that had been displaced and evaporated, This sudden cooling of the now Pacific ocean floor caused the quick deceleration of the moving continents forced the Rockey mountains of North America and the Andes Mountains of South America to form as the the edges pushed them selves up on top of the newly formed crust(ocean floor) and the rest of the continent tried to keep moving and the new weight of the Atlantic ocean crust that formed added its Mass/weight to the North and South American continents Forcing the Eastern coasts to push up with less Force to create the Appalachian, Acarai and Serra do Mar mountains. And so on and so forth.
You mentioned further, meaning this is only figuratively speaking. So why waste your time writing and our time reading about something that could possibly happen or possibly be happening, instead of writing a scientific, research paper? Why wouldn’t you actually perform the necessary research and measure known distances over time and factually check to see if your theory was correct?
Wonder if all that hot mantle rising is affecting the water temperatures and in turn some of the climate? Nah…it’s just humans and cow farts. CO2 is poison. People bad. Must become eco-fascists or it’s too late! Oh and don’t pay attention to the sun…it definitely has nothing to do with our climate and any of it’s changes.
Geologist have known for decades that the European and American continents are separating by I think it was a few inches? a year??? I can’t remember the exact distance. It has been way too many years since I learned that.. And that the American continent is getting closer to the European continent as well. That is where the ring a fire comes in in the Pacific. That is where the North American plate is going underneath the Asian plate and the heat from the grinding of the bed rock is causing the bedrock to become more magma, which is causing the volcanoes a.k.a. the ring of fire. However, what we didn’t know is about the deep up swelling, deeper than 60km, that may be also partially causing the separation. I believe that is what this article is about.