New research suggests that the blobs buried deep in Earth's mantle may be a billion years old. | Credit: KATERYNA KON/SCIENCE PHOTO LIBRARY via Getty Images Continent-size islands deep inside ...

Here’s how it works. Continent-size islands deep inside Earth's mantle could be more than a billion years old, a new study finds. Known as large low-seismic-velocity provinces (LLSVPs), these ...