Huge freshwater reserves beneath the ocean

[Greg Bernhardt]

Scientists discover huge freshwater reserves beneath the ocean
http://www.sciencedaily.com/releases/2013/12/131208085304.htm

A new study, published December 5 in the international scientific journal Nature, reveals that an estimated half a million cubic kilometers of low-salinity water are buried beneath the seabed on continental shelves around the world.
The water, which could perhaps be used to eke out supplies to the world's burgeoning coastal cities, has been located off Australia, China, North America and South Africa.

 

[klimatos]

Scientists discover huge freshwater reserves beneath the ocean
http://www.sciencedaily.com/releases/2013/12/131208085304.htm

As always, the Devil is in the details. How saline is "low-salinity". Desalinization plants using ordinary saline sea water are in use all over the world. Would the decrease in salinity of this sub-surface supply produce enough savings to compensate for the added expense of drilling and pumping?

 

[phinds]

I also wonder if another problem might be that pumping large amounts of water out of such areas might cause collapse that would harm coastal cities, if the areas are close to the shore edge of the shelf. Just a thought.

 

[klimatos]

I also wonder if another problem might be that pumping large amounts of water out of such areas might cause collapse that would harm coastal cities, if the areas are close to the shore edge of the shelf. Just a thought.

Since the deposits are underwater, I think it more likely that sea pressure would simply force sea water into replace the withdrawn less-saline water. For the most part, our continental shelf is fairly porous. It would have to be, to hold the less saline water.

 

[Bystander]

Area of continental land masses is ca. 150 million sq. km.; area of continental shelves is ca. 4 million; volume of ground water is estimated to be 20 million cu. km. (give or take) --- half million in shelf aquifers is about right. Who wants to tell us there are no marine organisms that depend on fresh water seeps, springs, or other seafloor outlets?

 

[phinds]

Since the deposits are underwater, I think it more likely that sea pressure would simply force sea water into replace the withdrawn less-saline water. For the most part, our continental shelf is fairly porous. It would have to be, to hold the less saline water.

Good point. It would imply another problem though, which is that as fresh water is drawn out it would be replaced by seawater, thus leading to greater salination of the fresh water. At first that wouldn't be a problem, but it could become one.