Scientists Discover Extra Layer in Earth's Mantle

With so many advancements and all eyes up in space, one could be forgiven for forgetting there are still a number of mysteries here on Earth. Recently, scientists discovered the possible existence of a new layer of tectonic plates in the planet's mantle that could be behind the strange series of earthquakes rocking the Pacific, according to a report from The Guardian.

University of Houston's Jonny Wu presented the preliminary evidence of this layer at a joint conference of the Japan Geoscience Union and the American Geophysical Union in Tokyo.

His team believes that these tectonic plates subducted into a water-rich layer of the mantle called the transition zone millions of years ago. Although most old subducted plates sink past this area and straight into the Earth's core, the western Pacific areas have so many plates that there's no space for them to sink further.

"The Pacific subduction rate is so fast that you've got to find space to get all the slab in there," Wu explained. "And east Asia has had such a long history of subduction it's jammed up. So this slab is forced to slide within the upper mantle and transition zone and be thrust under China."

These plates seem to be moving horizontally at speeds comparable to plates on the surface.

The movements of these plates within the transition zone can cause earthquakes similar to the way bends and breaks of regular tectonic plates can. Wu pointed out that 90 percent of the planet's deep seismicity over 500 kilometers deep are in the Tonga area where they discovered their slab.

In fact, the plate movements in the newly discovered layer could explain the Vityaz earthquakes in the mantle between Fiji and Australia.

Technological advancements in seismology allows scientists to explore the planet's interior more intimately than ever.

The study was published in the Journal of Geophysical Research.