Massive 'Lava Lamp' Blobs Deep Inside Earth Have Scientists Puzzled
Mysterious blobs of distinct rock are imaged using waves from earthquakes (model from French and Romanowicz, 2015, Nature).
Credit: Ed Garnero, Hongyu Lai, Arizona State University

Two continent-size blobs of hot — and possibly molten — rock can be found deep underground, about halfway to the center of the Earth, according to a new study. These curious structures — each of which is so large that it would be 100 times taller than Mount Everest — could be made up of materials that may shed light on how the Earth formed, the researchers said. 

One of the blobs is located beneath the Pacific Ocean, and the other can be found beneath the Atlantic. These underground structures start where the Earth's mantle meets the core, but they send "plumes" up through the rock like a Lava Lamp, the researchers said.

Scientists now think these masses differ from the surrounding rock in more than just temperature. They're also "compositionally distinct," meaning they could contain materials not typically found in the rest of the Earth's mantle. Yet even some of the most basic information about the blobs is still a mystery. [Photo Timeline: How the Earth Formed]