KiSNeT - Königshafen Submarine Groundwater Discharge Network built to intense collaboration and knowledge across regional and disciplinary boundaries in the field of SGD research, setup as a joint experiment at the Königshafen/Sylt field site.
Submarine Groundwater Discharge (SGD) enables the exchange of water and chemical constituents between land and ocean. This has a major impact on coastal ecosystems. Although various studies at different sites around the world have demonstrated the importance of SGD for coastal ecosystems, the knowledge is still associated with high uncertainties.
The German scientific community offers a unique combination of disciplinary (biogeochemical, geophysical, biological) angles from which SGD is currently studied. It is revealed that an updated and intercalibrated catalogue of methods investigating SGD is necessary. This catalogue is postulated to provide recommendations for optimal disciplinary combinations to investigate SGD qualitatively and quantitatively. It would allow for a standardization of SGD measuring methodology and guarantee a comparability of study results, and subsequently a uniform SGD characterization. A diverse selection of SGD experts conceptualized an intercomparison experiment and identified the Königsberger Bay as a site at which all methods can be applied.
As a major result of KiSNeT, optimal interdisciplinary combinations for respective qualitative/ quantitative SGD investigations will be suggested reducing inherited uncertainties and paving the way for standardized SGD research.
The first field measurements were carried out in spring 2021. The measurement campaign focused on geophysical methods (ERT and GPR by LIAG and near-surface electromagnetics by BGR). However, it also included initial geochemical measurements (pore water sampling by IOW). The primary interest was to map the freshwater and saltwater distribution in the southern area of the Königsberg Bay in order to identify freshwater outflow zones and define areas for subsequent detailed sampling analyses. Three ERT profiles perpendicular to the coastline and one profile parallel to it allowed mapping of the groundwater distribution below the bay and clearly identified an area of groundwater seepage.
In addition, initial GPR profiles were measured across the dunes perpendicular to the shoreline to explore the groundwater table and map sediment structures. Both are important information for the construction of a groundwater model.
Prof. Dr. Mike Müller-Petke
+49 511 643-3253
Dr. Mathias Ronczka
Dr. Jan Igel
Helmholtz-Zentrum für Umweltforschung (UFZ)
Leibniz Zentrum für Marine Tropenforschung (ZMT)
Leibniz-Institut für Ostseeforschung Warnemünde (IOW)
Bundesanstalt f. Geowissenschaften und Rohstoffe (BGR)