Featured Research

from universities, journals, and other organizations

Vast freshwater reserves found beneath the oceans

Date:
December 8, 2013
Source:
Flinders University
Summary:
Scientists have discovered huge reserves of freshwater beneath the oceans kilometers out to sea, providing new opportunities to stave off a looming global water crisis. A new study reveals that an estimated half a million cubic kilometers of low-salinity water are buried beneath the seabed on continental shelves around the world.

New research reveals that an estimated half a million cubic kilometers of low-salinity water are buried beneath the seabed on continental shelves around the world.
Credit: DJ / Fotolia

Scientists have discovered huge reserves of freshwater beneath the oceans kilometres out to sea, providing new opportunities to stave off a looming global water crisis.

A new study, published December 5 in the international scientific journal Nature, reveals that an estimated half a million cubic kilometres 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.

"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 lead author Dr Vincent Post (pictured) of the National Centre for Groundwater Research and Training (NCGRT) and the School of the Environment at Flinders University.

"Knowing about these reserves is great news because this volume of water could sustain some regions for decades."

Dr Post says that groundwater scientists knew of freshwater under the seafloor, but thought it only occurred under rare and special conditions.

"Our research shows that fresh and brackish aquifers below the seabed are actually quite a common phenomenon," he says.

These reserves were formed over the past hundreds of thousands of years when on average the sea level was much lower than it is today, and when the coastline was further out, Dr Post explains.

"So when it rained, the water would infiltrate into the ground and fill up the water table in areas that are nowadays under the sea.

"It happened all around the world, and when the sea level rose when ice caps started melting some 20,000 years ago, these areas were covered by the ocean.

"Many aquifers were -- and are still -- protected from seawater by layers of clay and sediment that sit on top of them."

The aquifers are similar to the ones below land, which much of the world relies on for drinking water, and their salinity is low enough for them to be turned into potable water, Dr Post says.

"There are two ways to access this water -- build a platform out at sea and drill into the seabed, or drill from the mainland or islands close to the aquifers."

While offshore drilling can be very costly, Dr Post says this source of freshwater should be assessed and considered in terms of cost, sustainability and environmental impact against other water sources such as desalination, or even building large new dams on land.

"Freshwater under the seabed is much less salty than seawater," Dr Post says. "This means it can be converted to drinking water with less energy than seawater desalination, and it would also leave us with a lot less hyper-saline water.

"Freshwater on our planet is increasingly under stress and strain so the discovery of significant new stores off the coast is very exciting. It means that more options can be considered to help reduce the impact of droughts and continental water shortages."

But while nations may now have new reserves of freshwater offshore, Dr Post says they will need to take care in how they manage the seabed: "For example, where low-salinity groundwater below the sea is likely to exist, we should take care to not contaminate it.

"Sometimes boreholes are drilled into the aquifers for oil and gas exploration or production, or aquifers are targeted for carbon dioxide disposal. These activities can threaten the quality of the water."

Dr Post also warns that these water reserves are non-renewable: "We should use them carefully -- once gone, they won't be replenished until the sea level drops again, which is not likely to happen for a very long time."

The study, "Offshore fresh groundwater reserves as a global phenomenon" by Vincent E.A. Post, Jacobus Groen, Henk Kooi, Mark Person, Shemin Ge and W. Mike Edmunds, is published in the latest issue of Nature.

The National Centre for Groundwater Research and Training is an Australian Government initiative, supported by the Australian Research Council and the National Water Commission.


Story Source:

The above story is based on materials provided by Flinders University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Vincent E.A. Post, Jacobus Groen, Henk Kooi, Mark Person, Shemin Ge, W. Mike Edmunds. Offshore fresh groundwater reserves as a global phenomenon. Nature, 2013; 504 (7478): 71 DOI: 10.1038/nature12858

Cite This Page:

Flinders University. "Vast freshwater reserves found beneath the oceans." ScienceDaily. ScienceDaily, 8 December 2013. <www.sciencedaily.com/releases/2013/12/131208085304.htm>.
Flinders University. (2013, December 8). Vast freshwater reserves found beneath the oceans. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2013/12/131208085304.htm
Flinders University. "Vast freshwater reserves found beneath the oceans." ScienceDaily. www.sciencedaily.com/releases/2013/12/131208085304.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins