Discovery of massive underground ocean reshapes Earth's water origins
Scientists discovered a massive ocean hidden hundreds of miles beneath the Earth's surface a few years ago. Researchers claim that this underground ocean is three times larger than all the oceans on Earth's surface combined, suggesting that it may be the largest water reservoir in the world. However, it is worth noting that this ocean does not have a traditional form nor exist in liquid form.
The Earth service reminds us that scientists have long speculated about the existence of a massive ocean hidden beneath the Earth's surface, in the transition zone between the upper and lower mantle, at a depth of approximately 400 to 640 kilometres. In 2014, geophysicist Steve Jacobsen from Northwestern University and seismologist Brandon Schmandt from the University of New Mexico were the first to provide direct evidence of the existence of this structure, which they described in the scientific journal "Science."
Ocean under the United States
Researchers claim that the massive underground ocean is located beneath the surface of the United States at a depth of about 640 kilometres. They determined this through a network of seismographs that were deployed across the United States in 2000. These devices detected and analysed seismic waves from more than 500 earthquakes. As these waves travelled deeper into the planet, through the transition zone, their speed increased, indicating the presence of a vast water reservoir.
Experts emphasise that the underground ocean is different from what its name suggests. It does not exist in liquid or ice form. As explained by the Earth service, water is trapped in the molecular structure of minerals located in the Earth's mantle. The mineral that contains it is ringwoodite, a form of olivine. Ringwoodite, characterised by an intense blue colour, contains about 2.5 to 3% by weight of water.
This discovery offers a new perspective on the Earth's water cycle and could significantly impact the theory regarding the origin of water on our planet. The prevailing theory suggests that water arrived on Earth through asteroids or comets that hit the planet about 4.2–3.8 billion years ago, during the period known as the Late Heavy Bombardment. However, research conducted by Jacobsen and Schmandt indicates that water may have come from inside the Earth, gradually being released from its core.
