Offshore fresh groundwater reserves as a global phenomenon


The flow of terrestrial groundwater to the sea is an important natural component of the hydrological cycle. This process, however, does not explain the large volumes of low-salinity groundwater that are found below continental shelves. There is mounting evidence for the global occurrence of offshore fresh and brackish groundwater reserves. The potential use of these non-renewable reserves as a freshwater resource provides a clear incentive for future research. But the scope for continental shelf hydrogeology is broader and we envisage that it can contribute to the advancement of other scientific disciplines, in particular sedimentology and marine geochemistry.

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Figure 1: World map of topography and bathymetry showing known occurrences of fresh and brackish offshore groundwater.
Figure 2: Global overview of inferred key metrics and cross sections of well-characterised vast meteoric groundwater reserves.
Figure 3: The geology and the key groundwater flow, and dissolved salt transport processes below the continental shelf.


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Post, V., Groen, J., Kooi, H. et al. Offshore fresh groundwater reserves as a global phenomenon. Nature 504, 71–78 (2013).

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