Impression of the salt water intrusion in the subsoil of Friesland over the past 5500 years. The movie shows a cross-section with a depth of 240 m and a length of 60 km. The cross-section is orthogonal to the coast line and intersects with the village of Noard Burgum at 20 km from the coast. The left side represents the subsoil below the Wadden Sea. Red is salt water and blue represents fresh water.
For more information see: Van der Valk, M.J.H., 2011. A fresh-keeper for Noard Burgum. Delft, TU Delft.