Welcome to the latest installment of “Writer Fuel – cool real-world stories that might inspire your little writer heart. Check out our Writer Fuel page on the LimFic blog for more inspiration. Today:
A group of mysterious, ultradense structures just outside Earth’s core may be the remnants of an ancient interplanetary collision, new research suggests.
These strange structures are known as ultralow-velocity zones (ULVZs), because seismic waves generated by earthquakes travel about 50% more slowly through these zones than through the surrounding mantle. That means the ULVZs are also much denser than the rest of the mantle, and possibly made of heavier elements.
It’s hard to say anything for certain about these dense blobs of rock, because the ULVZs sit nearly 1,800 miles (2,900 kilometers) below Earth’s surface — one group clustered deep below Africa, and another below the Pacific Ocean, where the rocky mantle and liquid-metal outer core meet. That’s far too deep for human eyes to see; only seismic data can offer clues about the size, shape and structure of the ULVZs.