Kamchatsky, a coastal city in Russia’s Far East, at 11:24 pm Indian time on July 29. The earthquake area falls in the ...

Subduction occurs when one tectonic plate slides beneath another, recycling surface material back into Earth's mantle. The process often leaves visible evidence of movement, including volcanoes ...

The researchers speculate that the strange material may have been buried in the mantle since the Earth first formed, rather than having been a plate that sank in the past 200 million years.