It's surprising to learn that water envelops 71% of Earth's surface.
Okay, so maybe that one was a little too easy. But did you also know that there is a massive water reserve three times greater than the planet's surface seas hidden under the Earth's crust?
Scientists discovered in 2014 that, despite its first appearance, we really possess a hidden water resource under our feet.
Reaching this massive store of water is challenging since it is located 400 miles below the surface.
Furthermore, it resides within a blue rock known as "ringwoodite" that is located under the Earth's mantle and acts as a type of sponge for that enormous amount of water.
So, instead of being a liquid, solid, or gas, water is stuck in its fourth molecular configuration inside the mantle rock.
"The word ringwoodite is like a sponge sucking up water," geophysicist Steve Jacobsen said, contributing to the momentous finding. Ringwoodite's crystal structure is quite unique, which explains how it can draw hydrogen and hold onto water."
"This crystal can contain lots of liquid, depending on the conditions of the deep core."
Researchers from Northwestern College in Illinois used seismometers to measure the waves caused by US earthquakes, which led them to the finding of the wet rock.
They found out via their inquiry that the waves were not only going over the Earth's surface but also into the planet's core.
By examining the depth and wave speed, researchers were able to identify the kind of rocks that the water was contained in, and they finally came to the conclusion that ringwoodite was the source of the water's confinement.
Research indicates that the water content of ringwoodite may reach 1.5%.
If the water content of the ringwoodite molecules below the surface is just 1%, this suggests that there is three times as much water in the subsurface layer as there is in the whole surface ocean.
This discovery might help scientists better comprehend how the planet formed since it lends credence to the theory that Earth's water "came from within" rather than from asteroids and comets.
"I think that evidence of a whole-Earth water cycle is finally emerging, which might help explain the enormous volume of liquid water on the surface of our livable planet," Jacobsen said at the time.
"Researchers have been looking for this missing deep ocean for decades."
Thus far, scientists have only found signs of ringwoodite rock under the United States' surface. Jacobsen and the others are currently looking into whether this layer covers the whole world.