14 DAY TRIAL // According to scientists, mantle plumes are stretches of enormously hot rocks that can be found in the Earth's mantle. They come from tremendous depths, and some hypothesize that a few of the mantles originate from parts very close to the planet's core. The hot rocks are responsible for a lot of features on Earth, such as the Yellowstone National Park and the Hawaii Islands. Until now, physicists and geologists have believed that the plumes are immobile, but a new series of researches, combining computer simulations and plat tectonic history, among others, show that they may be, in fact, moving under the crust.
“In 2003, we showed that the hotspot – the plume – that created the Hawaiian chain of islands must have moved. We suggested that mantle motion was involved, but the cause of the change in motion remained a mystery,” John Tarduno, a geophysicist at the University of Rochester, who has been a leader of the new research, which has also involved experts from the Ludwig-Maximilians University, in Münster, Germany, and the Stanford University, says.
The investigators suggest that the head of the plume itself may have moved more than 1,000 miles under the Earth's crust, while its base has remained virtually in the same place. This hints to a “bending” phenomenon, the experts add, and not to a movement in the full sense of the term. One of the potential reasons why these movements may have occurred could be because plumes are a way for the planet's core to cool.
According to geologists, our planet loses the second largest amount of heat through mantle plumes, with the first one being that which is lost where tectonic plates meet each other. This knowledge has made some scientists maintain that tectonic movements are a colling system for the mantle, while the plumes fulfill the same role for the core, when temperatures get too high.
“We know from theory and from models, including work by Ulrich Hansen and Norm Sleep, that a plume can move slightly near its base, potentially contributing to motion of the Hawaiian hotspot and hotspots elsewhere. But a key observation came from a numerical simulation resulting from Hans-Peter Bunge's models, which show how the upper end of the plume, starting at 1500 depth, can drift like a candle flame drawn toward a draft,” Tarduno explains.