Science Alert
By David Nield
September 8, 2023
The most high-resolution map yet of the underlying geology beneath Earth’s Southern Hemisphere reveals something we previously never knew about: an ancient ocean floor that may wrap around the core.
This thin but dense layer exists around 2,900 kilometers (1,800 miles) below the surface, according to a study published in April. That depth is where the molten, metallic outer core meets the rocky mantle above it. This is the core-mantle boundary (CMB).