Hell is wetter than you thought: Diamond suggests that beneath the Earth's crust is an 'ocean’s worth of water'

Battered-looking diamond shows the Earth has a rather wet interior

A rare diamond that survived a trip from deep within the Earth's interior may have confirmed some theories that beneath the planet’s crust is an ocean’s worth of water.

In a study published on Wednesday in the journal Nature, scientists have found a battered-looking diamond from Brazil actually contains a water-rich inclusion of the olivine mineral ringwoodite, suggesting there is a very large amount of water held in the transition zone of the Earth’s mantle.

Samples from the transition zone are considered to be “exceedingly rare” and are only found in a small number of unusual diamonds, geochemist Hans Keppler said.

Most diamonds form at depths of about 150 to 200 kilometres (90 to 125 miles), but "ultradeep" diamonds come from the transition zone, which is 410 to 660 kilometres below the surface, Graham Pearson, a mantle geochemist at the University of Alberta in Edmonton said.

This particular diamond weighs just one tenth of a gram.

Mr Pearson said their discovery was almost accidental as his team had been looking for another mineral when they paid about $20 (£12) for a three-millimetre-wide brown diamond from the Juina district in Brazil in 2008.

 

His team studied the diamond and discovered a grain 40 micrometres across that turned out to be "ringwoodite" - a high-pressure form of olivine, a mineral that makes up much of the upper mantle of the Earth.

The upper mantle is a layer that lies between the planet’s crust and lower mantle.

Unlike other forms of olivine, ringwoodite can hold a substantial amount of water, meaning the sample could potentially resolve a long-standing debate over just how much water the transition zone contains.

The team found that its tiny speck of ringwoodite contained about 1 per cent  of its weight in water - a significant amount.

“That may not sound like much,” Mr Pearson told Nature News, “but when you realise how much ringwoodite there is, the transition zone could hold as much water as all the Earth’s oceans put together.”

"It's actually the confirmation that there is a very, very large amount of water that's trapped in a really distinct layer in the deep Earth," Mr Pearson added.

However, the results taken from one single crystal may not represent the entire transition zone, according to some scientists.

Speaking to Nature, Norm Sleep, a geophysicist at Stanford University in California compared the situation to panning for gold and discovering a large nugget. “It would be unwise to assume that all the gravel in the stream is gold nuggets,” he countered.

Mr Pearson agreed that further analysis is needed to test his theory, as other studies of the mantle have shown the water content in the transition zone is "spotty", and this sample may have come from one of the wet spots.

But tests could prove difficult because of the very small size of the mantle ringwoodite. “We have to think really carefully on what we do next on this sample because it’s very small: 40 micrometres,” he said. “That means you can only think of doing one or two additional analyses.”

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Senior Environmental Adviser - Maternity Cover

£37040 - £43600 per annum: Recruitment Genius: The UK's export credit agency a...

Recruitment Genius: CBM & Lubrication Technician

£25000 - £27500 per annum: Recruitment Genius: This company provides a compreh...

Recruitment Genius: Care Worker - Residential Emergency Service

£16800 - £19500 per annum: Recruitment Genius: Would you like to join an organ...

Recruitment Genius: Senior Landscaper

£25000 - £28000 per annum: Recruitment Genius: In the last five years this com...

Day In a Page

The long walk west: they fled war in Syria, only to get held up in Hungary – now hundreds of refugees have set off on foot for Austria

They fled war in Syria...

...only to get stuck and sidetracked in Hungary
From The Prisoner to Mad Men, elaborate title sequences are one of the keys to a great TV series

Title sequences: From The Prisoner to Mad Men

Elaborate title sequences are one of the keys to a great TV series. But why does the art form have such a chequered history?
Giorgio Armani Beauty's fabric-inspired foundations: Get back to basics this autumn

Giorgio Armani Beauty's foundations

Sumptuous fabrics meet luscious cosmetics for this elegant look
From stowaways to Operation Stack: Life in a transcontinental lorry cab

Life from the inside of a trucker's cab

From stowaways to Operation Stack, it's a challenging time to be a trucker heading to and from the Continent
Kelis interview: The songwriter and sauce-maker on cooking for Pharrell and crying over potatoes

Kelis interview

The singer and sauce-maker on cooking for Pharrell
Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

The addictive nature of Diplomacy

Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

Fashion: Ooh, Lady Chatterley!

Take inspiration from DH Lawrence's racy tome with equally racy underwear
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

Charlie Austin: ‘If the move is not right, I’m not going’

After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea