Photo by Yannis Papanastasopoulos
A team of geoscientists from the University of Leicester has helped confirm the existence of ancient freshened water sealed beneath the floor of the Atlantic Ocean – the first time such a system has been directly documented. The findings could have significant implications for understanding future freshwater resources in drought-vulnerable regions.
The team joined an international crew aboard the science vessel L/B Robert off the coast of New England last summer as part of a joint expedition between the International Ocean Drilling Programme (IODP) and the US National Science Foundation. During the voyage they collected sediment cores and around 10,000 litres of water from the freshened system beneath the seabed.
The water is thought to be tens of thousands of years old. Dr Andrew McIntyre, from the school of geography, geology and the environment at the University of Leicester, believes it may be linked to ice ages. “Maybe that water percolated through when sea levels were a lot lower, which allows it to reach around a hundred miles off shore,” he said. He added that understanding “the geological context, how that water got there, how old that water is, the chemistry of that water, the biology within it” was “really really important potentially for its future use.”
A resource for a thirsty world
Although oceans cover around 70% of the Earth’s surface, less than 3% of the planet’s water is fresh, and climate change is expected to increase both the frequency and severity of droughts globally. Freshened water, significantly less salty than seawater but not completely fresh, could represent a meaningful supplementary resource.
McIntyre said the discovery at one location pointed to a potentially much larger phenomenon: “This is just one location, there are many other locations around the world and potentially there’s a huge amount of water locked up in these systems. Understanding fresh water resources is really important, so this being fresher water than sea water, there potentially could be a future use for those regions that are particularly vulnerable to drought.”
New tools, new methods
IODP research fellow Dr Tim van Peer said the expedition had been technically innovative from the start. “We introduced new tools and new methods to explore this freshened water, which is a first for the scientific ocean drilling community,” he said.
In January the team travelled to the Centre for Marine Environmental Sciences at the University of Bremen to begin opening and analysing the samples. Van Peer said much work remained ahead: “These remarkable cores, water samples, and data will be open to the global community in a year from now. This marks the next phase of an exciting research journey. We can now for the first time discover how ancient the water is, how the sediments were deposited, and how these sediments can contain the water.”