Geologists have previously thought that tectonic plates move because they are pulled by the weight of their sinking regions and that an underlying, hot, softer layer called the asthenosphere acts as a passive lubricant. Now a team of geologists at the University of Houston has found that layer is flowing swiftly, moving fast enough to drive plate motions.
The team looked at minute changes in satellite-detected gravitational pull within the Caribbean and at mantle scans – similar to a CAT scan – of the asthenosphere under the Caribbean. They found a hot “river of rocks” being compressed from the Pacific Ocean through a gateway under Central America and reaching to the middle of the Caribbean Sea. This “river of rocks” started flowing eight million years ago.
Another very interesting discovery is that the asthenosphere is moving six inches per year, which is three times faster than an average plate. It can also move independently from the overlying plates and drag them in different directions.
Tubbs, S. (2021, March 11). Geologists discover powerful ‘river of rocks’ below Caribbean. Phys.org. https://phys.org/news/2021-03-geologists-powerful-river-caribbean.html