American Samoa’s volcanic plumes hold evidence that the earth molten core has been leaking iron out into the rest of the plant for billions of years says new research from the University of California and Aarhus University of Denmark.
In a paper published in Nature Geoscience researchers unpack how heavier iron isotopes are drawn to cooler temperatures outside of the 6,000 degree core and out towards the Earth’s mantle.
Two volcanic hot spots in American Samoa, Ofu and Vailuulu’u are the most likely candidates for places on Earth where the core has leaked iron all the way up to the surface.
Professor Charles Lesher from USC Davis said, “In our high- temperature high-pressure experiments, we show that in response to a large temperature drop, heavy iron isotopes migrate towards low temperature and lighter isotopes to high temperatures. “
The researchers found that lower temperatures draw the heavier iron isotopes away from the core, leaving behind the lighter ones, and with the hot spots in American Samoa enriched in heavy iron isotopes, Professor Lesher suggests this is another way to prove the theory.
He explained the chief reason we are concerned about core mantle interaction is that much of the heat that keeps our planet running like plate tectonics resides in the core and is escaping across the core mantle boundary.
“Since we cant go down and measure the heat flow like we do at the Earth’s surface we have to devise proxies to do the job,” said the professor.
These proxies are through computer simulations and experiments which look to match the scientists’ predictions about the geology with these observations.
