Geoscientists have used earthquakes to consider the composition of the lower portion of the Earth ’s drape under the Pacific Ocean – and they ’ve find something quite special . There are zone where the seismic moving ridge move in unlike manner , suggesting structures that are colder or have a different composition than the surrounding molten rock candy . The team describes the presence of these structures as a major mystery .
It is indecipherable what these structures are . If they were anywhere else , they could be portions oftectonic platesthat have drop down in a subduction geographical zone . But the Pacific is one large home plate , so there should be no subduction material under it . The research worker are also changeable about what form of material these rich social system are made of or what this entail for the internal structure of the planet .
" That ’s our dilemma . With the new high - resolution model , we can see such anomalies everywhere in the Earth ’s pall . But we do n’t recognise incisively what they are or what material is creating the patterns we have bring out , " Thomas Schouten , first author and doctorial student at the Geological Institute of ETH Zurich , allege in astatement .
The presence of so many cold region in the mantle propose that maybe they formed at dissimilar time and from unlike sources . They are not just subduction home base from the last 200 million years .
" We think that the unusual person in the grim mantle have a variety of ancestry , " explained Schouten . " It could be either ancient , silica - rich material that has been there since the formation of the mantle about 4 billion years ago and has survived despite the convective movements in the blanket , or zones where iron - productive rock’n’roll accumulate as a outcome of these mantle apparent movement over billions of years . "
More work is necessary . The squad is using just one unmarried property of the wave , their speed , to work out out so much of what goes on beneath our feet . Even with grand models , it is difficult to work out everything from just that . We can not give up the Earth and see what ’s in spite of appearance .
" We have to calculate the different fabric parameter that could generate the observed speeds of the unlike wave type . Essentially , we have to plunk deep into the material holding behind the wave speed , " explained Schouten .
A paper describing these findings is published in the journalScientific Reports .
