Jul 7, 2011 08:11 GMT  ·  By

In a groundbreaking new research, investigators were able to determine the existence of a new, previously-unstudied force that acts on our planet's tectonic plates, leading to their interactions.

This newly-found mechanism allows geologists and seismologists to gain a new perspective on the tectonic interplay taking place at subduction zones, where two or more tectonic plates meet.

Scientists now widely agree the Earth's continents and oceans sit atop giant rock plates, which float atop a thick layer of molten rock called the mantle. These plates make up our planet's crust. Oceanic plates are lighter and thinner, whereas continental plates are heavier and thicker.

There are numerous, powerful geological forces that interact to determine how these plates are set up across Earth's surface at any given time. Convection forces in the mantle are known to play one of the most important roles of all these factors.

Tectonic movements are responsible for a wide array of natural phenomena, such as for example the triggering of earthquakes, tsunamis or volcanic eruptions, or for the formation of mountain ranges.

But now scientists the University of California in San Diego (UCSD) Scripps Institution of Oceanography (SIO) bring a new perspective on this established theory. The team here says the hot plumes of magma pushing upwards from Earth's interior also play a huge role in the tectonic process.

The new study, led by SIO scientists Steve Cande and Dave Stegman, involved the use of advanced analytical methods to determine how Earth's crust plates moved about on the surface throughout the planet's billions of years of history.

Mantle plumes such as the ones they described were found to be active as recent as a few tens of millions of years ago, which is a relatively short time at a geological scale. Today, such plumes have been identified as active underneath Hawaii, Iceland and the Galapagos Islands.

One massive plume that developed about 70 million years ago is responsible for sending the Indian subcontinent slamming into Asia, leading to the formation of the Himalaya mountain range.

“Prior to the plume's arrival, the African plate was slowly drifting but then stops altogether, at the same time the Indian speeds up,” says Stegman, who holds an appointment as an assistant professor of geophysics at the SIO Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics.

“It became clear the motions of the Indian and African plates were synchronized and the Réunion hotspot was the common link,” he concludes, quoted by Daily Galaxy.