TSIL436 = The Secret in Locker 436
University of Maryland geophysicists reviewed and assessed thousands of recordings of seismic waves — sound waves traveling through the Earth — to identify echoes from the boundary between Earth’s molten core and the solid mantle layer above it.
The echoes exposed more widespread, heterogenous structures; i.e., areas of unusually dense, hot rock, at the core-mantle boundary than have been previously known.
From the June 12, 2020 press release:
In the illustration above, earthquakes send sound waves through the Earth. Seismograms record the echoes as those waves travel along the core-mantle boundary, diffracting and bending around dense rock structures. New research provides the first broad view of these structures, revealing them to be much more widespread than previously known.
Image credit: Doyeon Kim/University of Maryland.
Scientists are unsure of the composition of these structures, and previous studies have provided only a limited view of them. Better understanding their shape and extent can help reveal the geologic processes happening deep inside Earth. This knowledge may provide clues to the workings of plate tectonics and the evolution of our planet.
The new research provides the first comprehensive view of the core-mantle boundary over a wide area with such detailed resolution. The study was published in the June 12, 2020, issue of the journal Science.