Stunning megastructure discovered hidden beneath the Pacific

Scientists have discovered a peculiar section of Earth's interior beneath the Pacific Ocean near Easter Island that could shed light on the East Pacific Rise, the fastest-spreading ocean ridge on the planet.

At this site, ancient oceanic slabs are buried deep within the planet, possibly contributing to the ridge's expansion. These slabs date back to the age of dinosaurs. A team led by University of Maryland geologist Jingchuan Wang used seismic data to uncover these findings, as reported by *Science Alert*.

The team identified a slow-moving mantle anomaly beneath the Nazca Plate, which borders South America's continental plate. By using sound waves to create seismic maps, they discovered this blob of mantle material moving more slowly than expected. Earth's mantle, composed of heated silicate rocks, lies between the crust and core and circulates over millions of years due to temperature differences, with denser, cooler materials being drawn inward.

This process, known as subduction, is currently occurring under the Nazca Plate, which is being pulled beneath South America. However, beneath Easter Island, a rapidly growing ocean ridge exists along with a mysterious structural gap between the central and eastern Pacific.

Wang noted that their discovery raises new questions about how deep-Earth processes affect the surface across vast distances and time. The team found that the mantle material in this region was sinking at half the expected speed, suggesting that the mantle transition zone can act as a barrier, slowing material movement through the Earth.

Wang explained that this thickened area is a "fossilized fingerprint" of an ancient seafloor subducted into the Earth around 250 million years ago, providing an unprecedented glimpse into Earth's distant past. He and other scientists are refining their models of tectonic plate movements throughout Earth's history, believing there are many more ancient structures waiting to be discovered that could offer further insights into our planet's complex past and even aid in understanding other planets.