A scientific expedition off the coast of Massachusetts has confirmed the existence of a giant reservoir of freshwater hidden beneath the bottom of the Atlantic Ocean, a rare discovery that could change the way the history of water on Earth is understood.

According to researchers, the reservoir is about 20 years old and dates back to the last ice age. In theory, the amount of fresh water it contains could cover the needs of New York City for about 800 years. Scientists call this deposit one of the most impressive natural “fossils” of the ice age, suggesting that it was formed at a time when sea levels were much lower than today and the area was part of dry land.

The discovery raises new questions about the movement, storage and evolution of water resources on the planet, as well as the role that these hidden reserves may have played in past ecosystems. Experts emphasize that, despite the great theoretical potential, the exploitation of such a reservoir remains extremely complex and is currently more the subject of scientific study than a practical solution for water supply.