Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fresh water springs in oceans: A hidden water resource

10.07.2017

Geologist Nils Moosdorf and Till Oehler from the Leibniz Centre for Tropical Marine Research are reporting on an unusual natural phenomenon, which hasn’t as yet been covered much in science: submarine groundwater discharge. For many people living on the coasts these springs are of great benefit and cultural importance.

Olhos de Aqua – Eyes of Water – is the name of a popular holiday destination at the Portuguese Algarve. The name refers to an unusual natural phenomenon – during low tide fresh water flows from round springs to the surface.


Fresh water spring in the sea off Lombok. Where fresh and salty water mix, the water looks cloudy.

Imke Podbielski, Leibniz Centre for Tropical Marine Research


Indonesians collect fresh water from a spring on the beach in South Java.

Imke Podbielski, Leibniz Centre for Tropical Marine Research

Such springs are also present at the North Sea, for example in the flats near Sahlenburg at the southern end of the beach. At both locations coastal groundwater, having found its way through layers of rock or sand, flows along the gradient towards the sea. The water appears again near the water line or in some cases in up to 50 m sea depth as for example near the Croatian island of Braç. Such springs often exist in karst coastal regions made up mainly of cavernous limestone.

Submarine groundwater springs are widespread, but easy to overlook. Science hasn’t as yet given them much thought. “Quite wrongly”, says Nils Moosdorf, geologist at the ZMT. “It is estimated that submarine groundwater discharge makes up for up to 10% of the water carried into the sea through rivers.” Moosdorf studies the importance of such springs for humans and coastal ecosystems.

Together with his team he went on a search for submarine fresh water springs and got lucky finding evidence across the globe in ancient scripts, travel guides, diving magazines, press articles and through folk memory.

Often springs were used as a source for drinking water as for example in Bahrain in the Persian Gulf, where reports dating back to the 15th century talk of “a man being able to dive into the sea with a fur and fill it with fresh drinking water”.

In island states with a shortage of water such as Tahiti or Fiji the population still relies on fresh water springs if the water supply breaks down. Valuable rainwater is often collected in cisterns and will only be used for drinking. For washing people then use the fresh water springs at the beach.

“The springs are often extremely rich in nutrients”, explains Nils Moosdorf. “They attract a lot of fish. The so-called ‘Wonky Holes’ of the Australian coast are an example. They are hotspots for fishers and divers alike due to their fish abundance.” The geologist adds: ”In Japan oysters from aquaculture thrive particularly well in the vicinity of such springs.”

In Peru water from submarine sources is pumped into lorries to be distributed across the country, in Greece it is used to water the fields. In the 1990s Florida even planned to tap submarine groundwater on large scale, as drinking water is running short in the city of Miami. One of the springs in the US state provides roughly up to 40 m3 of fresh water per second.

Some people shipwrecked survived only because of sea submarine groundwater discharge – as the ZMT scientists call the springs. One example is the crew of the whaling ship Essex which moved Herman Melville to write his novel Moby Dick.

“Fresh water flowing out of the ocean has something magical and inspires people’s imagination”, reckons Moosdorf. “In many places, submarine groundwater springs are meaningful and culturally important to people. In ancient Greece, for example, horses were sacrificed to the God Poseidon at such a spring near Argos.” The geologist can also report from Bali where the Hindu sea temple Tanah Lot was built on such a spring. Each year two million people go on pilgrimage to the location.

Despite their significance submarine springs are threatened. Well-drilling on land can lead to submarine groundwater springs drying up. Raw sewage and residues from farming can pollute the spring water. This is not just a problem for humans who use the springs for drinking but also for coastal ecosystems such as coral reefs growing nearby. Sea-level rise will further have an impact on the hydraulic conditions for submarine groundwater discharge.

Moosdorf sums up his work: “It is only when we take a closer look that the particular value of these invisible water resources becomes apparent. Scientists and managers of coastal regions should keep an eye on them.”

Publication
Moosdorf, N., and T. Oehler: "Societal use of fresh submarine groundwater discharge: An overlooked water resource." Earth-Science Reviews (2017).
http://www.sciencedirect.com/science/article/pii/S0012825216302641

About the Leibniz Centre for Tropical Marine Research
In research and education the Leibniz Centre for Tropical Marine Research (ZMT) in Bremen is dedicated to the better understanding of tropical coastal ecosystems. As an interdisciplinary Leibniz institute the ZMT conducts research on the structure and functioning of tropical coastal ecosystems and their reaction to natural changes and human interactions. It aims to provide a scientific basis for the protection and sustainable use of these ecosystems. The ZMT works in close cooperation with partners in the tropics, where it supports capacity building and the development of infrastructures in the area of sustainable coastal zone management. The ZMT is a member of the Leibniz Association.

Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft

More articles from Earth Sciences:

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

nachricht Drones survey African wildlife
11.07.2018 | Schweizerischer Nationalfonds SNF

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>