Earth may have underground ‘ocean’ three times that on surface

After decades of searching scientists have discovered that a vast reservoir of water, enough to fill the Earth’s oceans three times over, may be trapped hundreds of miles beneath the surface, potentially transforming our understanding of how the planet was formed.

The water is locked up in a mineral called ringwoodite about 660km (400 miles) beneath the crust of the Earth, researchers say. Geophysicist Steve Jacobsen from Northwestern University in the US co-authored the studypublished in the journal Science and said the discovery suggested Earth’s water may have come from within, driven to the surface by geological activity, rather than being deposited by icy comets hitting the forming planet as held by the prevailing theories.

“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,” Jacobsen said.

“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. Scientists have been looking for this missing deep water for decades.”

Jacobsen and his colleagues are the first to provide direct evidence that there may be water in an area of the Earth’s mantle known as the transition zone. They based their findings on a study of a vast underground region extending across most of the interior of the US.

Ringwoodite acts like a sponge due to a crystal structure that makes it attract hydrogen and trap water.

If just 1% of the weight of mantle rock located in the transition zone was water it would be equivalent to nearly three times the amount of water in our oceans, Jacobsen said.

The study used data from the USArray, a network of seismometers across the US that measure the vibrations of earthquakes, combined with Jacobsen’s lab experiments on rocks simulating the high pressures found more than 600km underground.

It produced evidence that melting and movement of rock in the transition zone – hundreds of kilometres down, between the upper and lower mantles – led to a process where water could become fused and trapped in the rock.

The discovery is remarkable because most melting in the mantle was previously thought to occur at a much shallower distance, about 80km below the Earth’s surface.

Jacobsen told the New Scientist that the hidden water might also act as a buffer for the oceans on the surface, explaining why they have stayed the same size for millions of years. “If [the stored water] wasn’t there, it would be on the surface of the Earth, and mountaintops would be the only land poking out,” he said.

Earth may have underground ‘ocean’ three times that on surface

After decades of searching scientists have discovered that a vast reservoir of water, enough to fill the Earth’s oceans three times over, may be trapped hundreds of miles beneath the surface, potentially transforming our understanding of how the planet was formed.

The water is locked up in a mineral called ringwoodite about 660km (400 miles) beneath the crust of the Earth, researchers say. Geophysicist Steve Jacobsen from Northwestern University in the US co-authored the studypublished in the journal Science and said the discovery suggested Earth’s water may have come from within, driven to the surface by geological activity, rather than being deposited by icy comets hitting the forming planet as held by the prevailing theories.

“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,” Jacobsen said.

“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. Scientists have been looking for this missing deep water for decades.”

Jacobsen and his colleagues are the first to provide direct evidence that there may be water in an area of the Earth’s mantle known as the transition zone. They based their findings on a study of a vast underground region extending across most of the interior of the US.

Ringwoodite acts like a sponge due to a crystal structure that makes it attract hydrogen and trap water.

If just 1% of the weight of mantle rock located in the transition zone was water it would be equivalent to nearly three times the amount of water in our oceans, Jacobsen said.

The study used data from the USArray, a network of seismometers across the US that measure the vibrations of earthquakes, combined with Jacobsen’s lab experiments on rocks simulating the high pressures found more than 600km underground.

It produced evidence that melting and movement of rock in the transition zone – hundreds of kilometres down, between the upper and lower mantles – led to a process where water could become fused and trapped in the rock.

The discovery is remarkable because most melting in the mantle was previously thought to occur at a much shallower distance, about 80km below the Earth’s surface.

Jacobsen told the New Scientist that the hidden water might also act as a buffer for the oceans on the surface, explaining why they have stayed the same size for millions of years. “If [the stored water] wasn’t there, it would be on the surface of the Earth, and mountaintops would be the only land poking out,” he said.

Has Earth Splattered Life All Over the Solar System?

Lithopanspermia: put that word in your “cool new space words” dictionary. But what does it mean? It means spreading life, preserved within chunks of Earth rock, after being hit by huge meteorite impacts. It also means that terrestrial life could be the proverbial space invaders of science fiction, and not vice versa.

In new research, scientists have investigated the probability of chunks of Earth’s crust being blasted from our planet’s surface by asteroid impacts over the past 3.5 billion years, potentially spreading the seed of life to other planets in our solar system.

As can probably be guessed from the name, lithopanspermia is a modification of the “panspermia” mechanism — the hypothesis that life can hop from one planetary body to the next, helped along by cataclysmic impact events. Hardy bacteria that evolved on Planet A are ejected from the surface trapped inside a chunk of rock. Should they be sufficiently shielded and have a certain flair for deep space living, they may survive (or even not survive — as the necropanspermia hypothesis posits) and be deposited on Planet B via meteorite, potentially spawning life there.

Mashable