A vast stash of low-salinity water is quietly sitting beneath the Atlantic seafloor off the U.S. Northeast, and scientists say it could be big enough to keep a city the size of New York supplied for centuries. An international research team drilled far offshore and pulled up sediment cores loaded with pore water that, in some spots, tested close to common drinking-water standards. The discovery immediately raises thorny questions about how you would even reach such a resource, what it might do to the marine environment, and who, if anyone, could legally claim the water.
During IODP³-NSF Expedition 501 the science party recovered sediment cores and ran groundwater pumping tests that yielded nearly 50,000 liters of pore water from several drill holes. Those samples documented freshened groundwater in a roughly 200-metre-thick zone beneath the continental shelf, according to IODP. After the shipboard work wrapped up, an onshore science team began an intensive phase of splitting and analysing the cores at the Bremen Core Repository.
Where the water sits and how old it might be
Expedition 501 drilled at sites south of Nantucket and Martha’s Vineyard, reaching layers roughly 1,300 feet (about 400 metres) below the seafloor. Along the sampled transect, salinity measurements dropped from levels near typical drinking-water values to several parts per thousand farther offshore. Early radiocarbon, noble-gas and isotope results suggest the groundwater was emplaced during the last glacial period, possibly on the order of 20,000 years ago, according to preliminary findings reported by Live Science.
Freshness, volume and what that actually means…