Earth’s Mantle Moves 10 Times Faster Than Previously Estimated
Geologists have recently created a global map of convection currents, which are basically wave like motions inside the Earth's mantle. On studying the map, it has reportedly been found that convection currents move approximately 10 times faster than previously believed. Furthermore, the chaotic and fast movement of magma in the mantle causes our planet's surface to go up and down by as much as five kilometers over a time period of million years.
A team of scientists from the University of Cambridge were the first to map the magma flow within the Earth's mantle. The experts analyzed more than 2,100 measurements of ocean depth to understand how the currents move in the mantle, because there are lots of reasons that can change the ocean's depth. However, according to the study, if all other factors are removed then the mantle currents can be looked at on its own.
The study, published in Nature Geoscience, revealed that convection currents in the mantle move faster than previously thought. In the past, it was suggested that the currents were around 10,000 kilometers from top to bottom. However, the recent observations by researchers suggest that the figure would be nearer to 1,000 kilometers. The shorter currents have more power which implies they move quicker than was thought until now. The Earth's surface evolves much faster when the currents move faster. The convection currents initiate the creation of islands, mountains and volcanoes, apart from forcing the Earth's surface upwards or downwards depending on the current's strength.
According to the study, the surface movement also has consequences on ocean circulation. "For example, the Gulf Stream runs from Mexico to the North Atlantic, and comes back on itself deeper in the water. But, when the topography of the surface is higher, it blocks off the Gulf Stream," said Mark Hoggard from the University of Cambridge. "Considering that the surface is moving much faster than we had previously believed, it could also affect things like ice caps' stability and help us to understand past climate change." The researching team suggests that the discovery can help explain everything from how the surface of the Earth changes over time to the creation of fossil fuel deposits to long term climate change.