The scientists revealed that the volume of water present in the newly discovered underground oceans is equal to the volume of water bodies present on the Earth's surface. [Representational image]Reuters

Giant underground oceans have been discovered deep inside Earth's surface -- in its lower mantle. Scientists believe that if they dry up, all life forms will die.

These oceans, around 620 miles deep inside Earth's surface, were found with the help of two different studies. The researchers believe that these underground oceans are crucial for survival of life forms on our planet as they aid in tectonic activities.

One of the studies was conducted by researchers from Florida State University and the University of Edinburgh who guessed that a mineral called brucite can store water deep inside Earth's surface, the Sun reported.

The researchers, who conducted the second study, are from the Northwestern University in Illinois. They agreed with the revelations of the first study and implied that underground water can be found deep inside the Earth's core.

The amount of water present in these underground oceans is believed to be equal to the volume of water present on Earth's surface. The volume is guesstimated to be around 1.5 percent of our planet's mass.

And researchers believe the oceans churning deep beneath our feet are essential for life on Earth, since they are responsible for causing volcanoes and other tectonic activities which are crucial for soil formation and sustaining life on Earth.

If there is no volcanic eruption, no lava will be discharged which actually helps in making the soil more fertile and nutrient-rich. If there are no volcanic eruptions, it will become impossible to harvest crops. This is the reason why slopes of volcanoes have the world's most productive farms.

The underground waters are essential for a geological process called 'convention', which leads to giant rocks present in the Earth's interior to move. This movement causes magma to move upwards tearing the planet's tectonic plates apart and result into a volcanic eruption.

Hence, these underground oceans are really crucial for sustenance of life forms on Earth, the study concluded.