title: Origin and extent of fresh paleowaters on the Atlantic continental shelf, USA.
abstract: While the existence of relatively fresh groundwater sequestered within permeable, porous sediments beneath the Atlantic continental shelf of North and South America has been known for some time, these waters have never been assessed as a potential resource. This fresh water was likely emplaced during Pleistocene sea-level low stands when the shelf was exposed to meteoric recharge and by elevated recharge in areas overrun by the Laurentide ice sheet at high latitudes. To test this hypothesis, we present results from a high-resolution paleohydrologic model of groundwater flow, heat and solute transport, ice sheet loading, and sea level fluctuations for the continental shelf from New Jersey to Maine over the last 2 million years. Our analysis suggests that the presence of fresh to brackish water within shallow Miocene sands more than 100 km offshore of New Jersey was facilitated by discharge of submarine springs along Baltimore and Hudson Canyons where these shallow aquifers crop out. Recharge rates four times modern levels were computed for portions of New England's continental shelf that were overrun by the Laurentide ice sheet during the last glacial maximum. We estimate the volume of emplaced Pleistocene continental shelf fresh water (less than 1 ppt) to be 1300 km(3) in New England. We also present estimates of continental shelf fresh water resources for the U.S. Atlantic eastern seaboard (10(4) km(3)) and passive margins globally (3 x 10(5) km(3)). The simulation results support the hypothesis that offshore fresh water is a potentially valuable, albeit nonrenewable resource for coastal megacities faced with growing water shortages.
authors.affiliation: Department of Geological & Atmospheric Sciences, Iowa State University, Ames, IA 50011, USA.
authors.forename: Denis
authors.initials: D
authors.lastname: Cohen
authors.forename: Mark
authors.initials: M
authors.lastname: Person
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Carl W
authors.initials: CW
authors.lastname: Gable
authors.forename: Deborah
authors.initials: D
authors.lastname: Hutchinson
authors.forename: Andee
authors.initials: A
authors.lastname: Marksamer
authors.forename: Brandon
authors.initials: B
authors.lastname: Dugan
authors.forename: Henk
authors.initials: H
authors.lastname: Kooi
authors.forename: Koos
authors.initials: K
authors.lastname: Groen
authors.forename: Daniel
authors.initials: D
authors.lastname: Lizarralde
authors.forename: Robert L
authors.initials: RL
authors.lastname: Evans
authors.forename: Frederick D
authors.initials: FD
authors.lastname: Day-Lewis
authors.forename: John W
authors.initials: JW
authors.lastname: Lane
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water; D008962:Models, Theoretical; D009792:Oceans and Seas; D014481:United States; D014872:Water Movements