There Might Be a Giant Underground Ocean Hiding Beneath Our Feet
New insights into the origin of Earth’s water supply

For many years, scientists and astronomers theorized that water came to Earth on the backs of large icy comets that bombarded the planet in the distant past. In the earliest days of the solar system, impacts from comets, meteors, and asteroids were common. Some people think that these impacts could have brought water from space to our rocky planet. After all, there are no signs of water anywhere else in the near vicinity of our solar neighborhood. As interesting as the water-from-space theory is, there is another theory that is just as interesting, if not more so.
New data continues to hone in on water that is lying deep beneath our feet. This is not water sitting in easily accessible aquafers. This is water that is lurking 250 miles beneath the surface. Some scientists have begun calling this underground water an ocean. But that doesn’t quite paint an accurate picture.
Water In The Mantle
The surface of the Earth is called the crust. Lying just below the crust is the mantle, which is a large morass of liquid rock and strange crystallized material. For the longest time, most people believed that water could only exist in and on the crust of the Earth. The mantle is just too hot and has too much pressure to hold liquid water. But that assumption was wrong.
Scientists at Northwestern University have been testing seismic waves moving through the Earth. Using sensitive instruments and the shockwaves produced by earthquakes, researchers have discovered a large belt of water lying deep under our feet. These seismic waves move much slower through water than they do through solids or other types of liquid, like magma. Using this knowledge, it is easy to pinpoint the fact that there is definitely a variable ocean hiding in the mantle. The dramatic decrease in speed of seismic waves in this zone points to an abundance of water.
Just how much water could there be down there? More than three times all of the water currently resides in Earth’s oceans.
Sailing On The Underground Sea

The idea of an ocean’s worth of water hiding beneath the Earth’s crust will naturally evoke images of a large ocean contained in a massive cavern. These images are akin to something from Journey To The Center of the Earth, but that is not how the water is stored. This water is actually tied up within rocks, similar to how some natural gas and oil are contained within solid rock in the crust.
This underground water is contained in a rock called ringwoodite.
If you’ve never heard of ringwoodite, you’re not alone. Ringwoodite is a special type of rock formed at high pressures that only exists within the Earth’s mantle. Before this type of rock was found inside a meteorite in Australia, its existence was entirely theoretical. (Humans have never dug into the Earth’s mantle.) Ringwoodite is speculated to exist in huge quantities within the mantle. Scientists have long speculated that the mantle would create these kinds of rocks due to the conditions. Inside this rock hides the water that is being detected during seismic tests.

Ringwoodite has a bluish hue and contains water that was sealed inside during its high-pressure formation. Many of these formations are crystalline. Much of this water was reduced to hydroxide, which is sealed within these crystals.
Ringwoodite has been synthesized in a lab, and it was found to contain 2.6% of its weight in water or hydroxide. Using this number, scientists can extrapolate and infer how much water could be hiding within these deposits in the mantle. And the answer is that there is likely a lot of water down there.
Conclusion
The more we learn about the deep ocean and the world beneath our feet, the stranger it gets. In fact, we likely know far more about space than we do about the ocean floor and the mantle hiding under the crust. Most of the time, scientists are left filling in the blanks with hypothetical ideas based on readings taken from earthquakes and deep ground scans. But as a species, we have not dug very deep into the Earth. Everything else remains hidden from sight.
There is likely a lot of water within the Earth’s mantle, lurking well out of sight and trapped within rocks. The volume of this water could exceed all of that in the world’s oceans…combined…and multiplied by three. That means that Earth’s water did not fall from the heavens but has likely been here all along. The sheer amount of water hiding in the planet points to a reality in which the water likely formed with the Earth and has been here for the planet’s entire existence.
This discovery reminds me of the verse in Genesis which alludes to this level of water hiding inside of the Earth — on that day all the springs of the great deep burst forth.
