American scientists were nearly shocked to discover a previously unknown, strange, ancient structure surrounding the Earth’s iron core.
According to Science Alert, a study led by geologist Samantha Hansen from the University of Alabama (USA) utilized seismic waves to “see” into this mysterious structure deep within our planet, revealing a strange structural layer located at the core-mantle boundary (CMB).
Mysterious structures deep beneath the Earth’s surface could be remnants of an ancient ocean – (Photo: ARIZONA STATE UNIVERSITY).
Dr. Hansen and her team used 15 monitoring stations buried beneath Antarctica to map seismic waves over three years. These waves travel through the planet’s interior, so variations along their path reveal hidden structures.
They found that at the CMB, seismic waves traveled at significantly lower speeds compared to other areas, indicating a structure enveloping the planet’s core, which is extensive and includes mountains five times taller than Mount Everest.
While it is impossible to directly observe these unusual formations, the research team believes that they are remnants of an ocean floor—the substrate of several ancient oceans that have been buried deep through a process known as “subduction.”
Subduction is a process that occurs within a broader phenomenon called plate tectonics. Our planet’s crust is not seamless; it consists of more than 20 large and small plates that continuously move and slide over one another.
These plates are so numerous relative to the total surface area that they continually jostle, sliding over each other, carrying continents and oceans that have repeatedly shifted to form supercontinents and superoceans, then separating into the continents we see today over billions of years of history.
When an ocean narrows, subduction occurs somewhere within it, which can be understood as part of the ocean floor being swallowed by the Earth. Mysteriously, the tectonic plate—a fragment of the Earth’s crust—has carried this unknown ancient ocean deep down to this boundary instead of lingering in the upper part of the mantle like most other fragments.
The research findings were recently published in the journal Science Advances, where Dr. Hansen noted that this new discovery will provide important connections between the shallow and deep structures of the Earth, as well as the overall processes driving the evolution of our planet.
