Massive discovery deep under the Earth shocks scientists

Scientists have discovered a highly pressurized form of ice that they did not believe could exist on our planet.

Scientists have stumbled upon an entirely new type of water that they are calling Ice-VII, and they believe it is being caused by diamonds deep in the crust of the Earth. The extraordinary discovery could change our understanding of fluid pockets that reside hundreds of miles below the surface of the Earth.

This new type of ice is about 1.5 times as dense as the ice we’re familiar with, which is called Ice I. It has an entirely different atomic composition, and it is similar to what is found on ice moons that would orbit planets like Jupiter or Saturn. Ice VII has an entirely different structure than Ice I, with a cubic structure rather than a hexagonal one.

While it is possible to create Ice VII on Earth with enough pressure, scientists did not think it could be found on Earth because it is too warm to even form Ice VII, and even more unlikely that it could be stable. The scientists were looking for a rare type of carbon dioxide when they made the discovery.

The full statement from the University of Nevada Las Vegas follows below.

A UNLV scientist has discovered the first direct evidence that fluid water pockets may exist as far as 500 miles deep into the Earth’s mantle.

Groundbreaking research by UNLV geoscientist Oliver Tschauner and colleagues found diamonds pushed up from the Earth’s interior had traces of unique crystallized water called Ice-VII.

The study, “Ice-VII inclusions in Diamonds: Evidence for aqueous fluid in Earth’s deep Mantle,” was published Thursday in the journal Science.

In the jewelry business, diamonds with impurities hold less value. But for Tschauner and other scientists, those impurities, known as inclusions have infinite value, as they may hold the key to understanding the inner workings of our planet.

For his study, Tschauner used diamonds found in China, the Republic of South Africa, and Botswana that surged up from inside Earth. “This shows that this is a global phenomenon,” the professor said.

Scientists theorize the diamonds used in the study, were born in the mantle under temperatures reaching more than 1,000-degrees Fahrenheit.

The mantle – which makes up more than 80 percent of the Earth’s volume – is made of silicate minerals containing iron, aluminum, and calcium among others.

And now we can add water to the list.

The discovery of Ice-VII in the diamonds is the first known natural occurrence of the aqueous fluid from the deep mantle. Ice-VII had been found in prior lab testing of materials under intense pressure. Tschauner also found that while under the confines of hardened diamonds found on the surface of the planet, Ice-VII is solid. But in the mantel, it is liquid.

“These discoveries are important in understanding that water-rich regions in the Earth’s interior can play a role in the global water budget and the movement of heat-generating radioactive elements,” Tschauner said.

This discovery can help scientists create new, more accurate models of what’s going on inside the Earth, specifically how and where heat is generated under the Earth’s crust.

In other words: “It’s another piece of the puzzle in understanding how our planet works,” Tschauner said.

Of course, as it often goes with discoveries, this one was found by accident, explained Tschauner.

“We were looking for carbon dioxide,” he said. “We’re still looking for it, actually.”

The abstract from the paper follows below.

Small inclusions in diamonds brought up from the mantle provide valuable clues to the mineralogy and chemistry of parts of Earth that we cannot otherwise sample. Tschauner et al. found inclusions of the high-pressure form of water called ice-VII in diamonds sourced from between 410 and 660 km depth, the part of the mantle known as the transition zone. The transition zone is a region where the stable minerals have high water storage capacity. The inclusions suggest that local aqueous pockets form at the transition zone boundary owing to the release of chemically bound water as rock cycles in and out of this region.

Water-rich regions in Earth’s deeper mantle are suspected to play a key role in the global water budget and the mobility of heat-generating elements. We show that ice-VII occurs as inclusions in natural diamond and serves as an indicator for such water-rich regions. Ice-VII, the residue of aqueous fluid present during growth of diamond, crystallizes upon ascent of the host diamonds but remains at pressures as high as 24 gigapascals; it is now recognized as a mineral by the International Mineralogical Association. In particular, ice-VII in diamonds points toward fluid-rich locations in the upper transition zone and around the 660-kilometer boundary.

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