The world’s oldest water, which is locked deep within the Earth’s crust, is present at a far greater volume than was thought, scientists report. The liquid, some of which is billions of years old, is found many kilometres beneath the ground.
Researchers estimate there is about 11m cubic kilometres (2.5m cu miles) of it – more water than all the world’s rivers, swamps and lakes put together.
The study was presented at the American Geophysical Union Fall Meeting and has also been published in the journal ‘Nature’.
The team found that the water was reacting with the rock to release hydrogen: a potential food source, which means that great swathes of the deep crust could be harbouring life.
Prof Barbara Sherwood Lollar, from the University of Toronto, in Canada, said: “This is a vast quantity of rock that we’ve sometimes overlooked both in terms of its ability to tell us about past processes – the rocks are so ancient they contain records of fluid and the atmosphere from the earliest parts of Earth’s history.
“But simultaneously, they also provide us with information about the chemistry that can support life. And that’s why we refer to it as ‘the sleeping giant’ that has been rumbling away but hasn’t really been characterised until this point.”
The crust that forms the continents contains some of the oldest rocks on our planet. But as scientists probe ever deeper – through boreholes and mines – they’re discovering water that is almost as ancient. The oldest water, discovered 2.4km down in a deep mine in Canada, has been dated to between one billion and 2.5bn years old.
Find out more about this story here .