METEOR M196

On M196 we investigate a newly- discovered offshore freshened groundwater (OFG) site within the Gulf of Corinth, Greece. On the cruise, we will acquire and integrate electromagnetic and geochemical data to derive the spatial extent of OFG in the region, and understand if this low-salinity porewater anomaly in the sediments is due to present-day recharge through an onshore aquifer system or, alternatively, a remnant of past sea-level lowstands. The quality of groundwater is deteriorating globally, leading to an increase of pressure on water resources, particularly in coastal regions. In the quest for mitigating water scarcity under changing climatic conditions, alternative water sources such as offshore freshened groundwater (OFG) have come into scientific focus. Estimates suggest that globally the fresh water volume within OFGs amounts to half a million cubic kilometres. This volume corresponds to one century’s worth of freshened water assuming present-day consumption rates.

Although OFGs are considered to be a global phenomenon, spatial dimensions, volumes, and geological controls of freshened water beneath the seafloor are poorly constrained, since discoveries are based mainly on chance findings in boreholes. Few studies exist that effectively combine the point-scale ground-truthing data through boreholes with regional measurements to adequately constrain the spatial extents of OFG. Moreover, questions regarding OFG connectivity to its terrestrial counterpart remain largely unanswered.
On this cruise we investigate a newly- discovered OFG site within the Gulf of Corinth, Greece. The proposed cruise will acquire electromagnetic and geochemical data to derive the spatial extent of the Gulf of Corinth OFG, and understand if this low-salinity anomaly is due to present-day recharge through an onshore aquifer system or, alternatively, a remnant of past sea-level lowstands.