Scientists have discovered remnants of an ancient seabed that sank 250 million years ago in the depths of the Pacific Ocean. Experts suggest that this discovery, challenging current theories about Earth’s structure, could rewrite the history of the planet. Researchers found remnants of a long-lost seabed in the depths of the Pacific Ocean.
This ancient seabed, believed to be part of a massive tectonic plate that plunged into the depths 250 million years ago, has raised questions about existing theories regarding Earth’s internal structure. Jingchuan Wang, a researcher from the University of Maryland, stated, “Our discovery raises new questions about how the deep Earth affects what we see on the surface.”
Scientists discovered a region in the mantle transition zone, separating the upper mantle from the lower mantle, that is 19 kilometers thick and 1,900 kilometers long.
Wang mentioned, “This thickened region resembles a fossilized fingerprint of an ancient seabed that sank approximately 250 million years ago.” Subductions typically leave visible evidence such as volcanoes, earthquakes, and deep-sea trenches.
However, Wang noted that oceanic plates are often entirely consumed by the Earth and leave no noticeable trace on the surface. Experts suggested that this discovery revealed that material within the Earth’s interior moves slower than expected, leading scientists to consider the mantle transition zone as a barrier.
Researchers believe that the ancient seabed they discovered could explain the Pacific Large Low Shear Velocity Province (LLSVP), where seismic waves move slower. Wang suggested that this ancient structure could have divided the LLSVP.
The team also thinks that the remnants they found could belong to the Phoenix plate, which may have carried cooler material from the ocean floor to the warmer mantle, leaving a cold thermal signature. Planning to expand their research to other areas of the Pacific Ocean, the team aims to map out ancient subduction and uplift zones.
Wang stated, “We believe there are many more ancient structures waiting to be discovered in the deep interiors of Earth, each having the potential to offer new insights into our planet’s complex past.”