UA researchers: Ancient ocean floor near Earth’s core may have heat safety valves
Most people are familiar – or have heard of – the basic parts of Earth’s core: a “mantle” or mostly solid layer that goes from just below the crusty surface to the “core” – a very hot, round furnace at the planet’s center.
New findings based on research led by the University of Alabama has found evidence of a new layer between the core and mantle – made of parts of a sunken ocean floor – that may have a key role in how heat escapes the core itself.
“We are finding that this structure is vastly more complicated than once thought,” said UA geological sciences professor Dr. Samantha Hansen, one of the research paper’s co-authors. For example, the research found variations of the layers’ thickness “from a few kilometers to 10′s of kilometers,” said co-author Dr. Edward Garnero from Arizon State University. One kilometer is roughly .62 of a mile.
The two universities’ findings were published Wednesday in the journal Science Advances.
Hansen’s three years of seismic research involved burying 15 sensing stations in Antarctica much like a “medical scan of the body,” the University of Alabama said in announcement of the findings. Hansen, students and other researchers made four trips to Antarctica over three years to collect data focused on that core-mantle boundary – a region “that is pencil thin, measuring in the tens of kilometers, compared to the thickness of the Earth’s dominate regions.”
What came back was something new. “Unexpected energy,” the university said, and an analysis of thousands of seismic recordings from Antarctica found “thin anomalous zones of material at the (core-mantel boundary) everywhere we probed.” Garnero said. “The material’s thickness varies from a few kilometers to 10′s of kilometers. This suggests we are seeing mountains on the core, in some places up to five times taller than Mt. Everest.”
These mountains on the Earth’s core five times taller than Mount Everest, the tallest mountain on the surface, “may play an important role in how heat escapes from the core,” researchers said. Hansen said, “Our research provides important connections between shallow and deep Earth structure and the overall processes driving our planet.”