By Chris Skeldon 
Jingquan Wang. /University of Maryland
A team of scientists has identified a strange patch of land deep in the Pacific Ocean, which may explain why this region currently creates the world's fastest-spreading mid-ocean ridge – the East Pacific Rise.
jingxuan wang, Using seismic data, his colleagues at the University of Maryland have discovered ancient oceanic plates hidden deep within the Earth that may contribute to spreading, dating back to the time of the dinosaurs.
“Our discovery opens new questions about how the depths of the Earth affect what we see at the surface over vast distances and time scales,” says Wang. statement From the university.
during He studiespublished in Advancement of scienceThe researchers sent sound waves deep into the Earth to create seismic maps.
Wang and his team identified A A strange mantle patch is moving surprisingly slowly beneath the Nazca plate. Which borders the South American continental plate.
According to Science AlertMost of the Earth's volume consists of hot silicate rocks, sandwiched between a thin, cold crust and a hot, scorching core.
This layer of partially molten metal is called molten metal cloakflows in cycles over tens of millions of years, due to extreme temperature differences between the surface and the surface.
Dense, cooler matter is attracted to the hotter interior in a process called Subduction.
Wang et al. / Scientific progress
A diagram of the structures beneath the present-day Nazca plate
In this region, the Nazca plate is currently subducting beneath South America, but on the western side of the plate lies a rapidly rising mid-ocean ridge, a hotspot of geological activity beneath the Easter Islands, and a mysterious rift structure between the central Pacific Ocean and the Easter Islands. Eastern Pacific.
“We found that in this region, material was sinking at about half the expected speed, suggesting that the mantle transition zone may act as a barrier and slow the movement of material across the Earth,” Wang explains.
The team decided that this The slab structure is cooler and denser From its surroundings it appears to be a fossilized piece of ancient seabed.
“This thick area is like… Fossilized fingerprint From an ancient piece of seafloor that sank into the Earth about 250 million years ago. “It gives us a glimpse into Earth's past that we've never had before.”
Wang et al. / Scientific progress
Topography of the Nazca plate subduction zone
By not melting as completely as the surrounding mantle, the remains of what was once a planet remain Triassic sea floor They protrude deeper into the hotter layers of the mantle, causing material to reflect into structures, called… Super feathers.
“to Geodynamic simulation The team explained that the geometry and stability of lower mantle structures are due to their direct interactions with the subducting slab.
Researchers suspect that this series of anomalies, which orient themselves from east to west, It can help tell the story of the Nazca Mark And the way it has moved throughout Earth's history.
By deciphering the historical traces of these ancient influences deep within the Earth, geologists can learn more about how the inner workings of our planet shaped the surface of our world today.
“Seeing the ancient subducted plate gave us this perspective New knowledge About the relationship between very deep Earth structures and surface geology, which was not previously clear.
