''Scientists discover an ocean 400 miles beneath our feet that could fill our oceans three times over''
After
decades of theorizing and searching, scientists are reporting that they've finally found a massive reservoir of water in the Earth’s mantle — a reservoir
so vast that could fill the Earth’s oceans three times over.
This
discovery suggests that Earth’s surface water actually came from within,
as part of a “whole-Earth water cycle,” rather than the prevailing theory of
icy comets striking Earth billions of years ago. As always, the more we
understand about how the Earth formed, and how its multitude of interior layers
continue to function, the more accurately we can predict the future. Weather,
sea levels, climate change — these are all closely linked to the tectonic
activity that endlessly churns away beneath our feet.
This new
study, authored by a range of geophysicists and scientists from across the US,
leverages data from the Us Array — an array of hundreds of seismographs located
throughout the US that are constantly listening to movements in the Earth’s
mantle and core. After listening for a few years, and carrying out lots of
complex calculations, the researchers believe that they've found a huge reserve
of water that’s located in the transition zone between the upper and
lower mantle — a region that occupies between 400 and 660 kilometers
(250-410 miles) below our feet.
As you
can imagine, things are a little complex that far down. We’re not talking about
some kind of water reserve that can be reached in the same way as an oil well.
The deepest a human borehole has ever gone is just 12km — about
half way through the Earth’s crust — and we had to stop because geothermal
energy was melting the drill bit. 660 kilometers is a long, long way down, and
weird stuff happens down there.
Basically,
the new theory is that the Earth’s mantle is full of a mineral called
ringwoodite. We know from experiments here on the surface that, under extreme
pressure, ringwoodite can trap water. Measurements made by the Us Array indicate
that as convection pushes ringwoodite deeper into the mantle, the increase in
pressure forces the trapped water out (a process known as dehydration melting).
That seems to be the extent of the study’s findings. Now they need to try and
link together deep-Earth geology with what actually happens on the surface. The
Earth is an immensely complex machine that generally moves at a very, very slow
pace. It takes years of measurements to get anything even approaching useful
data.
With all
that said, there could be massive repercussions if this study’s findings are
accurate. Even if the ringwoodite only contains around 2.6% water, the volume
of the transition zone means this underground reservoir could contain enough
water to re-fill our oceans three times over. I’m not saying that this gives us
the perfect excuse to continue our abuse of Earth’s fresh water
reserves, but it’s definitely something to mull over. This would also seem to
discount the prevailing theory that our surface water arrived on Earth via a
bunch of icy comets.via-extremetech
Comments
Post a Comment