Freshwater Under the Ocean

June 18, 2019

Photo of the Atlantic Ocean, where scientists recently found freshwater off the northeastern coast of the United States. Image courtesy of worldatlas.com[1].

A study was published on June 18th, 2019 detailing how scientists have discovered a freshwater aquifer underneath the Atlantic Ocean. This aquifer contains about 2,800 cubic kilometers (670 cubic miles) of water and runs for about 220 miles[2].

Scientists were able to discover and map out the freshwater by using electromagnetic waves, which include waves from microwaves to X-rays and gamma rays. Electromagnetic waves conduct better in saltwater than freshwater due to saltwater having a higher concentration of compounds such as salts and trace metals. Dissolved salts and metals are very good at absorbing energy from electromagnetic waves, causing saltwater to have a higher conductivity compared to freshwater. Therefore, scientists were able to detect whether there was freshwater by looking for areas in the ocean that did not conduct the electromagnetic waves as well[2].

Regarding the formation of these aquifers, scientists believe that most of the water comes from melting glaciers from the last ice age about 20,000 to 15,000 years ago. Thus, there is a possibility that other aquifers have also formed in drier areas such as Southern California, Australia, the Mideast, or Saharan Africa, providing many people with a cheaper and more convenient source of freshwater[2].

However, researchers from the University of Delaware have found repercussions of using these freshwater aquifers that could lead to negative impacts on coastal areas and other freshwater sources. Many of these aquifers would be supplied with new freshwater through intricate underground systems that also connect to aboveground sources of freshwater[3].

Diagram of the water cycle that shows how water moves throughout an environment. Image courtesy of NASA[4].

Using the freshwater from these aquifers may cause more saltwater to mix in with the freshwater in the aquifer which could affect the groundwater and other sources, possibly causing changes that could impact many species. Examples include amphibians such as frogs that are extremely sensitive to the quality of water or fish that may live in lakes and streams. In addition, coastal cities exert pressure down on the ground due to gravity. The aquifer and groundwater creates an upward force that counteracts the city’s downward force so that everything is balanced. By removing freshwater from the aquifer, it is possible that the delicate balance will be shifted and the coastal city could start sinking as there is not enough pressure from the water[3].

Of course, we currently have no concrete evidence that any of this will happen if we use aquifers as researchers cannot model such complex systems. Should scientists find more of these aquifers in the future, it would be best to not abuse these new resources so that they may be available for future generations.

By Nathan Chan

Works Cited

[1] https://www.worldatlas.com/articles/countries-on-the-atlantic-ocean.html

- Image of the Atlantic Ocean

[2] https://www.livescience.com/65779-giant-freshwater-aquifer-east-coast.html

- Information about the discovery

[3] https://www.udel.edu/udaily/2019/may/fresh-water-under-ocean-groundwater-oil-drilling/

- Issues with using freshwater underneath the ocean

[4] https://pmm.nasa.gov/image-gallery/water-cycle

- Image of the water cycle