[Rockhounds] Scientists discover 'sunken worlds' hidden deep within Earth's mantle that shouldn't be there

[Kreigh Tomaszewski]

A new way of measuring structures deep inside Earth has highlighted
numerous previously unknown blobs within our planet's mantle. These
anomalies are surprisingly similar to sunken chunks of Earth's crust but
appear in seemingly impossible places.

Potential patches of Earth's ancient crust, sometimes called "sunken
worlds," may have just been discovered deep within the mantle, thanks to a
new way of mapping the inside of our planet
<https://www.livescience.com/planet-earth/geology/whats-inside-earth>.
However, these mysterious blobs appear in places they should not, leaving
researchers scratching their heads.

For decades, scientists have been building up a better picture of Earth's
interior <https://www.livescience.com/tag/earth-s-interior> by using
seismographs — 3D images created by measuring how seismic waves from
earthquakes reverberate deep within our planet. This method has helped
scientists identify ancient sections of the planet's crust, known as
subducted slabs, that have been pulled into the mantle through subduction
zones where tectonic plates
<https://www.livescience.com/37706-what-is-plate-tectonics.html> meet. For
example, in October 2024, researchers announced the discovery of a section
of seafloor that had sunk deep into the mantle below Easter Island
<https://www.livescience.com/planet-earth/geology/many-more-ancient-structures-waiting-to-be-discovered-lost-chunk-of-seafloor-hidden-in-earths-mantle-found-off-easter-island>
.

In a study published Nov. 4, 2024, in the journal Scientific Reports
<https://go.redirectingat.com/?id=92X1588396&xcust=space_us_1175496999301487627&xs=1&url=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs41598-024-77399-2&sref=https%3A%2F%2Fwww.space.com%2Fthe-universe%2Fearth%2Fscientists-discover-sunken-worlds-hidden-deep-within-earths-mantle-that-shouldnt-be-there>,
researchers revealed that they had discovered "numerous" potential
subducted slabs throughout Earth's mantle, using a new type of
seismographic imaging. (Little information about the size, shape and exact
locations of the blobs has been revealed so far.)

https://www.space.com/the-universe/earth/scientists-discover-sunken-worlds-hidden-deep-within-earths-mantle-that-shouldnt-be-there