Environment

Huge reserves of freshwater lie beneath the ocean floor

Scientists have found huge freshwater reserves under the world's oceans (Photo: Shutterstock)
Scientists have found huge freshwater reserves under the world's oceans (Photo: Shutterstock)

Scientists in Australia have reported the discovery of huge freshwater reserves preserved in aquifers under the world's oceans. The water has remained shielded from seawater thanks to the accumulation of a protective layer of sediment and clay. And it’s not a local phenomenon. Such reserves are to be found under continental shelves off Australia, China, North America and South Africa.

The discovery was made by researchers at the National Centre for Groundwater Research and Training (NCGRT) and the School of the Environment at Flinders University. The scientists estimate there is around half a million cubic kilometers of what they describe as “low salinity” water, which means it could be processed into fresh, potable water economically.

The reserves formed when ocean levels were lower and rainwater made its way into the ground in land areas that were not covered until the ice caps melted 20,000 years ago, causing sea levels to rise.

"The volume of this water resource is a hundred times greater than the amount we’ve extracted from the Earth’s sub-surface in the past century since 1900," says study lead author Dr. Vincent Post. "Our research shows that fresh and brackish aquifers below the seabed are actually quite a common phenomenon."

To access these non-renewable water reserves, it would be necessary to drill into the seabed from man-made, offshore platforms or from the mainland or nearby islands. Despite the high costs involved, the water would require less energy to desalinate than it does to desalinate sea water, although a careful assessment of the economics, sustainability and environmental impact of the exploration of such water reserves would be necessary.

Post added that humanity needs to be careful not to contaminate these aquifers while drilling for oil or disposing of carbon dioxide as suggested in some carbon capture and storage proposals.

Water scarcity is set to be one of the biggest environmental challenges of the 21st century, with global warming, deforestation, overpopulation, industrial demand, irrigation and several other factors taking a huge toll on the planet’s water reserves. According to UN-Water, in 2011 some 768 million people lacked access to suitable sources of drinking water. Seawater desalination plants are becoming a more widely-used source of drinkable water, but the process is generally costly and extremely energy-intensive.

The team's research is described in a paper published in the December 5th issue of Nature.

Source: Flinders University

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17 comments
Scion
Oh great, now we can exploit more non-renewable resources until we suddenly discover what terrible damage we have done. Then we'll try to convince people to go sparingly on the water and they'll claim hoax and complain that economic activity will suffer etc etc...
While this find is interesting I am obviously shocked that the first thought is to suck all the water out and use it. Shouldn't we be stopping the awful wastage of fresh water we do today?
BeWalt
Wonderful! Another one-time resource we can squander and postpone the actual dealing with the issue (aka not wasting resources like a bunch of hogs) to our children and grandchildren.
We humans are geniuses.
Nairda
Hmm,. now we just need to find another similar reserve of oil for the next 100 years and we're set,... :b
Slowburn
I suggest that we capture the water from the burning of hydrocarbon fuel.
yinfu99
Are people that silly? Other than what bleeds off into space is reclaimed by the planet. Once you consume water, it doesn't disappear....The Oceans are a renewable source of water. Do we have to work to use it again via desalination? sure. but then if we want to use wood, another renewable resource, we have to grow the trees, cut them down, process them, etc...Our water is not just disappearing people, not like your thinking anyway. On a similar note oil is being recycled into carbon and other products. Its just going to take longer to recycle them that one might some aluminum cans or such things. There is no black hole where our resources are falling into once they are used.
CliffG
It may not be that simple to suck that water out. On dry-land aquifers the level merely drops as air permeated down to where the water was. What replaces removed water when the aquifer is under the ocean? It seems like a recipe for its immediate contamination.
Think, then think again before doing it.
David Clarke
Why not pump down carbon dioxide, then we could have our own soda fountain? As far as desalination plants go, why can't they be operated using solar energy, either directly by evaporating water with solar heat, or using solar panels to generate electricity and evaporate the water that way? That way they don't cost much to operate.
fenshwey
it would be better to switch all our water consumption to sea water that has been desalinated. We should also try use the sea in production of hydrogen.
We should ban the use of fresh water. Sure it takes energy to desalinate water, but the sea creates wave energy, and wind energy, and we have sun energy, lets harvest that energy and use the sea as a renewable resource.
Once we start using the sea we will never have to issue hose pipe bans or go thirsty again, and also, it would be nice to see the maths to figure out how much we could use and would it have an impact on sea levels.
Slowburn
Using water out of a aquifer at a sustained rate faster than it is replenished is fairly stupid but using it as a reservoir to get through a drought makes sense.
For desalinization it should be noted that there is very little difference in the design of the boiler in a steam cycle power plant and a steam cycle desalinator.
As for what to do with the brine study Israel's dead sea industry.
Stephen N Russell
Is this worldwide?? wow if so.