Gigantic Ocean Discovered 400 Miles Beneath Earth’s Surface Challenges What We Know About the Planet’s Water

July 25, 2024 | Source: GOOD | by Neha B.

Earth’s abundance of water is what makes it a “blue planet.” Scientists have long speculated about how all this water ended up here. Some studies suggested that water arrived on Earth through collisions with icy comets or asteroids. However, the question persisted: Did Earth’s water come from outer space or from within? A 2014 study provided insight into this mystery when scientists discovered a massive reservoir of water trapped within hot mantle rocks. The findings were published in the journal Science.

The discovered reservoir contains three times the volume of all Earth’s oceans combined. It was surprising, because usually, the Earth’s mantle, 254 to 410 miles deep, is an efflux of scorching hot rocks covered with magma. According to New Scientist, scientists have long believed that the mantle’s “transition zone,” the boundary between the upper and the lower mantle, could contain water trapped in rare minerals.

During this study, they finally discovered a colossal body of water trapped inside a blue rock called ringwoodite. Ringwoodite is a deep blue mineral, chemically similar to peridot, a green mineral often used in jewelry. “The ringwoodite is like a sponge, soaking up water,” Steven Jacobsen of Northwestern University in Evanston, Illinois, said, per a university press release. “There is something very special about the crystal structure of ringwoodite that allows it to attract hydrogen and trap water. This mineral can contain a lot of water under conditions of the deep mantle.”