Scientists 'see' puzzling features deep in Earth's interior:
New research led by the University of Cambridge is the first to obtain a detailed 'image' of an unusual pocket of rock at the boundary layer with Earth's core, some three thousand kilometres beneath the surface.
The enigmatic area of rock, which is located almost directly beneath the Hawaiian Islands, is one of several ultra-low velocity zones – so-called because earthquake waves slow to a crawl as they pass through them.
[...] Earth's interior is layered like an onion: at the centre sits the iron-nickel core, surrounded by a thick layer known as the mantle, and on top of that a thin outer shell — the crust we live on. Although the mantle is solid rock, it is hot enough to flow extremely slowly. These internal convection currents feed heat to the surface, driving the movement of tectonic plates and fuelling volcanic eruptions.
[...] The researchers used the latest numerical modelling methods to reveal kilometre-scale structures at the core-mantle boundary. According to co-author Dr Kuangdai Leng, who developed the methods while at the University of Oxford, "We are really pushing the limits of modern high-performance computing for elastodynamic simulations, taking advantage of wave symmetries unnoticed or unused before."
[...] With images of the ultra-low velocity zone beneath Hawaii now in hand, the team can also gather rare physical evidence from what is likely the root of the plume feeding Hawaii. Their observation of dense, iron-rich rock beneath Hawaii would support surface observations.
[...] The team's observations add to a growing body of evidence that Earth's deep interior is just as variable as its surface. "These low velocity zones are one of the most intricate features we see at extreme depths – if we expand our search, we are likely to see ever-increasing levels of complexity, both structural and chemical, at the core-mantle boundary," said Li.
Journal Reference:
Zhi Li, Kuangdai Leng, Jennifer Jenkins, Sanne Cottaar. Kilometer-scale structure on the core–mantle boundary near Hawaii. Nature Communications (2022), DOI: 10.1038/s41467-022-30502-5
(Score: 0) by Anonymous Coward on Thursday May 26 2022, @10:36PM
Did we just find Mordor?
I knew Sauron was in Hawaii, what a slacker!
(Score: 2) by Joe Desertrat on Friday May 27 2022, @12:20AM (1 child)
Now they need to see if there are similar features under other hot spots like Yellowstone and such.
(Score: 3, Interesting) by khallow on Friday May 27 2022, @03:17AM
These structures are huge, underlying Africa and the Southern Pacific, and are at least hundreds of kilometers thick. Nobody understands why they exist or what causes the structure we can observe, but it's thought that these are billions of years old. Current theories include that these are dumping grounds for remnants of oceanic plates or the last traces of the protoplanet Theia, which is thought to have collided with early Earth to form the modern Earth-Moon system.
(Score: 2) by MIRV888 on Friday May 27 2022, @03:09AM
I've always wondered why the volcanic spot which created Hawaii is stationary relative to the movement of the Pacific plate.
I thought the mantle was a more viscous fluid though.
Definitely curious to see where this research leads.