The oceans are not as level as you might think. Scientists estimate that the Atlantic Ocean actually widens by a few centimeters each year. At the same time, the Pacific Ocean is shrinking.
This glacial slow-moving ocean is due to the constant movement of the earth’s tectonic plates, as the plates below the Americas pull apart from those below Europe and Africa.
The deep, geophysical forces that underlie this epic phenomenon are far from fully understood, but researchers may have just identified an important contributor to what is happening there.
In a new study, scientists suggest that mid-ocean ridges – mountainous formations that pop up along the seabed between tectonic plates – may be more involved in the transfer of material between the upper and lower mantles beneath the earth’s crust than we previously realized .
The 39 seismometer locations. (University of Southampton)
“Zinc plates and emerging plumes are widely accepted as transfer sites, while the middle ocean ridges usually do not play a role,” a team led by seismologist Matthew Agius of the University of Southampton in the UK said in a new article explained.
“But strict restrictions of in situ measurements at ridges are a challenge. ‘
To fill the gaps in our knowledge, the researchers deployed a fleet of 39 seismometers along the bottom of the Atlantic Ocean to record seismic movements below the Mid-Atlantic Ridge – the boundary that separates America and America and Europe tectonically. .
Seismic measurements recorded in the experiment monitored the flow of material in the mantle transition zone lying between the upper and lower mantle, enabling the team to transfer material at depths as far below the ground as 660 kilometers (410 miles) ) below the surface.
The results suggest that chemical material conditions are not limited to shallow depths in the Mid-Atlantic Reef, but that they may appear in the deepest parts of the mantle’s transition zone, indicating that material rises from the lower mantle.
“The observations imply the transfer of material from the lower to the upper mantle – either continuous or intermittent – linked to the Mid-Atlantic Ridge,” the researchers explain.
“Given the length and longevity of the middle ocean edge system, this implies that convection of the entire mantle occurs more than previously thought.”
Use one of the seismometers. (University of Southampton)
Although it was already known that ridges in the middle of the ocean contributed to the phenomenon of the distribution of the seabed, the new findings show that the overall processes extend much deeper into the earth than previously measured, and that even in parts of the seabed may occur. characterized by open areas of plate suppression.
“[The work] refutes overall assumptions that ridges in the ocean may play a passive role in plate tectonics, ‘says senior researcher and geophysicist Mike Kendall of Oxford University.
“This suggests that forces on the ridge play an important role in places such as the Mid-Atlantic to drive newly formed plates apart.”
The findings are presented in Earth.