Geoscientists have used earthquakes to study the composition of the low-pitched percentage of the Earth ’s mantle under the Pacific Ocean – and they ’ve disclose something quite queer . There are zones where the seismic waves move in different ways , advise structures that are cold or have a different composition than the surrounding liquefied rocks . The squad describes the comportment of these structures as a major secret .
It is unclear what these social organization are . If they were anywhere else , they could be serving oftectonic platesthat have drop down in a subduction zone . But the Pacific is one large plate , so there should be no subduction material under it . The researcher are also uncertain about what kind of textile these deep structures are made of or what this means for the intimate structure of the planet .
" That ’s our dilemma . With the new mellow - resolution model , we can see such anomalies everywhere in the Earth ’s pallium . But we do n’t know incisively what they are or what textile is creating the patterns we have uncovered , " Thomas Schouten , first author and doctoral student at the Geological Institute of ETH Zurich , said in astatement .
A visualization of where colder material in the mantle is located, courtesy of a new computer model.Image Credit: Sebastian Noe / ETH Zurich
The front of so many cold region in the mantle suggests that maybe they formed at different times and from different sources . They are not just subduction plate from the last 200 million years .
" We reckon that the anomalies in the lower mantle have a miscellany of origins , " excuse Schouten . " It could be either ancient , silica - robust material that has been there since the formation of the mantle about 4 billion class ago and has survive despite the convective movements in the mantle , or geographical zone where iron - rich rocks accumulate as a consequence of these mantle movements over billions of year . "
More work is necessary . The squad is using just one single belongings of the waves , their speed , to work out so much of what goes on beneath our feet . Even with fantastic role model , it is difficult to exploit out everything from just that . We can not open up the Earth and see what ’s inside .
" We have to aim the different material parametric quantity that could generate the observed speeds of the different wave case . Essentially , we have to plunge deeper into the material property behind the wave speed , " excuse Schouten .
A newspaper describing these findings is publish in the journalScientific Reports .
Anearlier versionof this story was published in January 2025 .
