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).
"Seismic investigations, such as ours, provide the highest resolution imaging of the interior structure of our planet, and we are finding that this structure is vastly more complicated than once thought," said geologist Samantha Hansen from the University of Alabama when the findings were announced.
Understanding exactly what's beneath our feet – in as much detail as possible – is vital for studying everything from volcanic eruptions to the variations in Earth's magnetic field, which protects us from the solar radiation in space.
Hansen and her colleagues used 15 monitoring stations buried in the ice of Antarctica to map seismic waves from earthquakes over three years. The way those waves move and bounce reveals the composition of the material inside Earth. Because the sound waves move slower in these areas, they're called ultralow velocity zones (ULVZs). READ MORE...
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