No matter what you might have learned in physics lessons , the Earth is not a pure sphere . The gravitative potential across its surface can vary quite a number , due to the density of the material under your feet . Whether you ’re in Melbourne or Montreal , you might have unlike material below you .
The map of this gravitational potential is called the " geoid " and it bring out something quite peculiar – there ’s a big chunk of masses missing underneath the Indian Ocean . Its cause has been an enduring mystery , however researcher now suggest that the mantle beneath the Amerind subcontinent has a deal more hot and light material than expect . The new research is reported inGeophysical Research Letters .
" The beingness of the Indian Ocean geoid low is one of the most outstanding problems in Earth Sciences , " lead source Professor Attreyee Ghosh , from the Indian Institute of Science , suppose in astatement . " It is the lowest geoid / gravity anomaly on Earth and so far no consensus exist regarding its seed . It is remarkable as it mean that there is some mass deficit in the deep mantle that ’s causing the low-toned . "
If the ideal geoid is envision as a perfect welkin , the Indian Ocean geoid scummy ( IOGL ) would be equivalent to a depression of over 100 meters ( 328 invertebrate foot ) . scientist had previously suggested that beneath the causa of the anomaly was an ancient oceanic plate that sink below the Indian plate jillion of years ago . This explanation left many unconvinced and the team searched for alternative ideas . They look at how seismal waves propagate through the Earth ’s DoI and found that there seemed to be low - density material under the IOGL . But where does that material come from ?
They believe it comes from the African superplume , a large upwelling in the blanket that is literally ( but lento ) splitting Africa apart . The hot material from the superplume seem to be getting deflected E and stopping at the IGLO .
" Most of the existing theory have tried to excuse this negative anomalousness with the help of cold , dense pelagic plates that slump into the mantle in the past , " says Professor Ghosh . " Our subject field explain this humble with hotter , lighter textile stretching from a deepness of 300 km ( 186 statute mile ) , up to ~900 km ( ~559 miles ) , in the northern Indian Ocean , most likely stemming from the African superplume . "
The team plans to study how the IOGL has evolved over time in the hopes that this will allow for more supporting evidence for their hypothesis .
