The solution to our water scarcity may lie in the most unexpected place: under the Atlantic

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Aquifers and other groundwater are one of the most valuable natural resources we have. Although they are a renewable resource, they are not unlimited, so it is necessary to look for new aquifers. A study carried out in 2019 can open a new path for us, that of searching for these sources of water at the bottom of the sea.

A resource in danger.
The overexploitation and pollution are two of the aquifers are the two big problems that lie in wait for the aquifers. Aquifers are renewable resources, since they receive water progressively. However, if the water is extracted at a higher rate than they receive water, they end up emptying.

Aquifer water is a resource that is relatively easy to access more or less legally. This gives rise to a typical case of “tragedy of the commons”, that is, that different agents make use of a well limited based on their particular interests, trying to maximize their own benefit even when the collective damage of this management may exceed the private benefit.

The contamination of aquifers can be due to many reasons. A typical form of aquifer contamination is seepage of fertilizers and nitrates in aquifers located in agricultural areas. Pollution can also occur in a more natural way, for example by the seepage of salt water into coastal aquifers.

The largest aquifer under the sea.
It is therefore not surprising that finding new freshwater reserves is a priority for many. One of the most hopeful recent findings was announced three years ago by researchers at Columbia University. The aquifer is located under the waters of the Atlantic, off the north of the US East Coast in the strip between the states of Massachusetts and New Jersey.

The finding was surprising for several reasons. In the first place because, due to the permeability of some soils, finding fresh water under one of the largest masses of salt water in the world is striking. Secondly by the size of the aquifer. According to the team that discovered and mapped it, the mass of water could contain more than 2,700 cubic kilometersthe equivalent of a lake of almost 40,000 square kilometersalmost half of the total area of ​​Andalusia.

It would be a more or less continuous aquifer, made up of well-connected deposits, starting from the same coast and entering the ocean along the North American continental shelf. It could reach 130 kilometers deep.

Search by land and sea.
The procedure with which the Atlantic aquifer was found can help us find new similar bodies of water. The team led by Chloe Gustafson, then a doctoral student at Columbia University’s Lamont-Doherty Earth Observatory, used electromagnetic waves to locate it and define its extent.

They made two passes with different devices. One capable of measuring subsurface electromagnetic fields that were dropped onto the seabed; and a second capable of emitting and receiving these electromagnetic pulses. As salt water is a better conductor of electromagnetic waves than fresh water, the receiving devices can distinguish the profile of each one of them.

Hope against the drought.
Water is one of the most basic resources required by human beings, due to its direct consumption, but it is also an essential part of our economy. hopefully the problem gets worse on all fronts: more and more people require more water to survive; the water cycle changes and we expect more and more droughts and more concentrated rainfall that we cannot take advantage of properly; And as if that were not enough, demographic pressure also implies more waste that harms the water reserves that we have.

In this context, finding new sources of water will be of great importance in the future. Knowing that it can be found under the 2/3 of the earth’s surface where we haven’t looked for it is good news. Still, caution is necessary. In the first place because we do not know how much water can be found in these places, but above all because extracting it it will not be easy. Not much less cheap.

Terrestrial aquifers are easily accessible but extracting water from under the seabed without contaminating it will be a task that requires complex extraction infrastructures. To this must be added the construction of aqueducts to transfer it to other areas. Areas such as the western United States or Africa can benefit from the discovery of new aquifers, but getting water to them will not be an easy task. Perhaps we should still try to make better use of the aquifers that are close at hand before resorting to those hidden by the ocean.

Image | NOAA

Aquifers and other groundwater are one of the most valuable natural resources we have. Although they are a renewable resource,…

Aquifers and other groundwater are one of the most valuable natural resources we have. Although they are a renewable resource,…

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