Huge underground ‘ocean’ discovered near Earth’s core

Geologists have discovered evidence of a vast underground ocean deep beneath the Earth’s surface, in a breakthrough that may change our understanding of the history of the planet.

In a study published in the journal Science, researchers report the finding of a vast reservoir of water three times the size of any ocean, located 400 million miles deep, near to the planet’s core.

The water is not in liquid form – it is not even ice or vapor. It is trapped inside the molecular structure of the minerals acting like sponges in the mantle rock.

Thanks to the intense pressure and temperatures of more than 2,000 degrees Fahrenheit, some water is squeezed out of the rock as if it were sweating, lead author of the study Steve Jacobsen, of Northwestern University, explained.

However, by using 2,000 seismometers – instruments normally used to detect movements of the planet’s surface – across the United States to measure the speed of seismic waves passing through the body of mineral-bound water, alongside Jacobsen’s laboratory observations, the researchers can be sure that it is there. 

Scientists have long speculated that our oceans originated from the depths of the Earth, and have been looking for such a discovery for decades.

“Geological processes on the Earth’s surface, such as earthquakes or erupting volcanoes, are an expression of what is going on inside the Earth, out of our sight,” said Jacobsen.

“I think we are finally seeing evidence for a whole-Earth water cycle, which may help explain the vast amount of liquid water on the surface of our habitable planet.” 

Jacobsen stressed that their survey only revealed the evidence of reservoirs beneath the US, saying further research would be needed elsewhere. 

However, the new discovery provides the biggest indication yet that the oceans – the source of life on Earth – rose from the rocks. 

Photo: NASA Goddard Space Flight Center via Flickr 

Further reading:

John Kerry: the oceans are ‘under siege’

Tropical fish stocks under increasing pressure, study finds

World Oceans Day: ‘we can each do something to help protect our ocean’

Current rate of ocean acidification eclipses ancient extinction event

John Kerry: degradation of marine environment ‘doesn’t know borders’