Graham Pearson presentation draws big crowd at British High Commission

A large crowd turned up to the British High Commission’s Science Salon series to hear Graham Pearson, Canada Excellence Research Chair in Arctic Resources at the University of Alberta, talk about his team’s recent discovery of ringwoodite.

Pearson, one of the world’s leading scientists in diamond studies and in understanding the formation of diamond-forming roots beneath continents, made the recent discovery inside a three-millimetre-wide, brown, impure diamond.

Not only was this the first time that terrestrial ringwoodite had been found (previous samples had all been extra-terrestrial, from meteorites), analysis of the mineral found that it contained a significant quantity of water.

This allowed Pearson to confirm a long-held scientific theory: there are enormous volumes of water trapped 410 to 660 kilometres beneath the Earth, between the upper and lower mantles, in the transition zone.

Pearson explained how the discovery had transformed his research, and had been the second-most covered news story in the world during the week of its publication in Nature magazine.

“The discovery was accidental,” he said. “We were actually looking for another mineral when we bought the host diamond, and the sample of ringwoodite is invisible to the naked eye.”

As with many scientific discoveries, Pearson acknowledges his luck in finding the sample, but said the CERC funding had enabled him to locate it, identify it, and build the research partnership responsible for the work.

“It was very fortunate,” said Pearson. “I make the analogy with fishing. You have to be fishing and have your line in the water if you want to catch a fish. If you are not out there looking, you won’t find anything. The funding I get from the CERC program made the research possible.”

Graham Pearson’s discovery of ringwoodite confirms vast quantities of water in the transition zone.

(Credit: Richard Siemens/University of Alberta)