Scientists Just Found a Hidden Underground Ocean So Massive It Holds 3x More Water Than All the Oceans Combined

The oceans cover about 71% of the Earth’s surface. This vast body of water is crucial for the continued existence of life on the planet, as it regulates the climate and temperature, and supports life both in the water and outside of it. This is why, when scientists search for signs of life in space, they often look for celestial bodies that might contain liquid water.

Now, new discoveries are pointing out that we may have more water than previously thought. Deep beneath the Earth’s crust, between the upper and lower mantle, scientists have discovered an underground reservoir of water so vast it equates to three times the volume of all oceans on the surface combined.

Trapped in Crystal

The water found between 250–700 km deep in the mantle transition zone is not in free-flowing liquid form like the ones in our oceans. It is chemically bound with a mineral called ringwoodite.

This crystallized structure acts like a sponge that traps the water inside, and it was formed by the intense pressure below the Earth’s surface. The weight and size of the Mantle’s transition zones, which contain these materials, are so massive that even if just 1% of it were water, it would be 3x the amount of water in all our oceans combined.

Laboratory studies have shown that when ringwoodite is exposed to a simulation of intense pressure from being 700 km in depth, and about 1500 °C in temperature, it would be able to hold water inside its rocky minerals.

Read more: The Guardian

Seismic Signals Reveal the Hidden

Scientists Just Discovered A Vast Hidden Ocean Inside Earth

If the water reservoir is deep within the crust and mantle, then how did the scientists find out about it? They didn’t do it by drilling all the way to those transition zones, but rather by observing the seismic waves generated by Earthquakes.

Scientists have found out that the waves slowed down dramatically when passing through the ringwoodite layers. There was also an analysis of a large dataset from over 2,000 seismometers, which further verifies the hypothesis, as it revealed consistent velocity anomalies in the transition zone.

This is indirect evidence, but based on what we know about seismic waves, it should not slow down if it passes through a solid object or layer. However, it is expected to change velocity if there is a presence of water, primarily because water is less dense, and the transfer of energy from one particle to another will not be as quick as that of solid materials.

The Whole-Earth Water Cycle

These whole new discoveries and theories support what we already know about the Earth-Water cycle. Also known as the hydrologic cycle, it refers to the movement of water above and below the surface of the Earth.

In the specific subduction zones, surface water will be dragged down below the crust into the mantle, and will mix with minerals and other solid materials due to the intense pressure and temperature changes, until they are uplifted to the surface again by volcanic activity later on.

In other words, the theory that there is a large water reservoir in the mantle transition zones, which are chemically combined with ringwoodite, is supported by a verified and well-understood natural process, the Earth-water cycle.

Read more: Brookhaven National Library

Impacts on Earth Science

The presence of these hydrated minerals in the mantle transition zones affects the models of Earth’s evolution, including the stability of our oceans, and how the climate will be affected long-term. Some scientists are also trying to find out whether that area of the Earth could hold some form of life after all, as water is a fundamental necessity, as we know it.

As of today, more research is needed to find out if this water reservoir spans the whole globe or just concentrated in the subduction areas. It could also change how we look at some other planets, because maybe their water is still deep below their surface, and the possibility of life being able to survive there is not completely zero.

Scientists Just Found Earth’s Largest Underground Ocean

Author's Final Thoughts

The discovery of an underground ocean that could hold three times more water than all of our surface oceans combined reminds us that we do not fully understand our own planet. It still hides so much mystery, and as we find out more about it, the easier it will be to look for other planets that could sustain life just like ours.

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