A new study led by the University of Cambridge is the first to take a detailed photograph of an unusual rock border with an Earth’s crust, about 3,000 miles [3,000 km] underground.
The rugged terrain, located almost directly below the Hawaiian Islands, is one of the few places with the lowest speed — the so-called epicenter.
The study, published today in Nature Communications, is the first to reveal the intricate internal variations of one of these packages in more detail, illuminating the appearance of the Earth’s deepest interior and the processes that operate within it.
“Of all the deep inner layers of the Earth, these are the most interesting and complex objects. We now have the first solid evidence to show their inner structure – it is a real milestone in the deepest seismology of the Earth,” said lead author Zhi Li, a Ph.D. student at the Cambridge Department of Earth Sciences.
The interior of the Earth is coated with an onion: in the center sits an iron-nickel core, surrounded by a thick layer of the mantle, and on top of that, there is a thin outer shell — the crust in which we live. Although the mantle is a hard rock, it is hot enough to flow very slowly. These internal convection currents supply heat to the surface, driving the tectonic plates and speeding up the volcanic eruption.
Scientists use earthquake waves from seismic to see underground — echoing the shadows of these waves, revealing radar-like images of deep internal topography. But until recently, photographs of buildings along the core-mantle border, an area of great interest in studying the flow of heat within our planet, have been complex and challenging to explain.
Researchers have used sophisticated modeling methods to identify the kilometer-long structures in the main border of a garment. According to co-author Dr. According to Angdai Leng, who developed these techniques while at Oxford University, “We are really pushing the computer limits of high performance elastodynamic simulations, taking advantage of invisible or unused wave symmetries.” Leng, currently based in the Science and Technology Facilities Council, said this meant they could improve image processing with a more extensive system than the previous work.