A team of scientists in America have discovered a large structure made of dense material near the Earth's core some 3,000km (1,864m) beneath our feet, having shared their findings in the journal Science today.
The researchers from the University of Maryland used a machine-learning algorithm to probe what was happening deep inside the Earth, finding an anomaly that has never been detected before.
According to Vice, the algorithm they used was one that was originally developed to analyse distant galaxies, but this time it led them to a mysterious phenomenon within our own world.
The anomoly they discovered was far below the Marquesas Islands, a group of volcanic islands in French Polynesia, while another structure beneath Hawaii was also found to be much larger than scientists had estimated before.
"We used a manifold learning algorithm called 'The Sequencer' to simultaneously analyze thousands of seismograms of waves diffracting along the core-mantle boundary and obtain a panoptic view of scattering across the Pacific region," the paper's abstract explains.
"In nearly half of the diffracting waveforms, we detected seismic waves scattered by three-dimensional structures near the core-mantle boundary. The prevalence of these scattered arrivals shows that the region hosts pervasive lateral heterogeneity.
"Our analysis revealed loud signals due to a plume root beneath Hawaii and a previously unrecognized ultralow-velocity zone beneath the Marquesas Islands.
"These observations illustrate how approaches flexible enough to detect robust patterns with little to no user supervision can reveal distinctive insights into the deep Earth."
The team, which was led by Doyeon Kim, a seismologist and postdoctoral fellow at the University of Maryland, took seismograms captured from hundreds of earthquakes that had happened between 1990 and 2018 and fed them into the 'Sequencer' algorithm.
In doing this, they were able to analyse 7,000 measurements of earthquakes with a magnitude of 6.5 or higher, which had all taken place under the Pacific Ocean within that window of three decades.
Kim told Vice in a call: "This study is very special because, for the first time, we get to systematically look at such a large dataset that actually covers more or less the entire Pacific basin."
He noted that, while scientists have previously mapped out structures deep inside Earth, this study presents a rare opportunity to 'bring everything in together and try to explain it in a global context'.
After running the seismograms through the algorithm, the team realised that the strongest post cursor signals were found beneath the Marquesas and Hawaii islands, proving that there are two 'mega-ULVZs' (huge structures made up of exotic materials that date back to the times before Earth had a Moon) that zpanaround 1,000km (621m) or more.
Kim said: "This is very interesting because this might indicate that mega-ULVZs are special and may host primitive geochemical signatures that have been relatively unmixed since early Earth history."
The team plans to continue the research to develop a method of exploring what is inside the Earth, with hopes to look what also lies beneath the Atlantic Ocean.
"We're hoping that Sequencer will be able to basically let us use all of these diverse datasets and bring them together to look for these lower mantle structures systematically," Kim added.
"That is our vision going forward, to answer more questions about the lower mantle in general."Featured Image Credit: Flickr/Tom Patterson