Hidden ocean beneath the earth's surface could redefine water origins

Earth Service reports that scientists have uncovered a vast ocean hidden hundreds of miles beneath the Earth's surface. This subterranean body of water is estimated to be three times larger than all the world's oceans, potentially making it the largest water reservoir. Unlike typical oceans, this one is not in liquid form.

Earth service reminded readers that the idea of a massive, concealed ocean between the upper and lower mantle, within the transition zone at depths ranging from about 249 to 404 miles, has been speculated for years. Geophysicist Steve Jacobsen of Northwestern University and seismologist Brandon Schmandt of the University of New Mexico first provided concrete evidence of its existence in a 2014 issue of the scientific journal Science.

Research indicates that this extensive subterranean ocean lies beneath the United States' surface, reaching depths of approximately 404 miles. By deploying numerous seismographs across the USA in 2000, researchers analyzed seismic waves from over 500 earthquakes. The waves increased speed at deeper levels, suggesting the presence of a vast water reservoir, according to their findings.

However, experts clarify that this underground ocean does not resemble traditional bodies of water. It is neither liquid nor ice. Earth service explained that the water is instead trapped within the molecular structures of minerals in the Earth's mantle, specifically within a mineral known as ringwoodite—a type of olivine. Ringwoodite, noted for its intense blue hue, comprises about 2.5 to 3 percent water by weight.

This groundbreaking discovery offers new insights into the Earth's water cycle and could significantly impact our understanding of how water arrived on our planet. While it has been commonly believed that water was delivered via asteroids or comets during the so-called Great Bombardment around 4.2–3.8 billion years ago, Jacobsen's and Schmandt's research suggests that water could have originated from within Earth, slowly making its way to the surface from the core.