Pejrup, Morten5; Andersen, Thorbjørn Joest6; Johannessen, Peter N4; Nielsen, Lars Henrik4; Fruergaard, Mikkel6
1 Geography, Department of Geosciences and Natural Resource Management, Faculty of Science, Københavns Universitet2 SCIENCE Dean's Office, SCIENCE Faculty Office, Faculty of Science, Københavns Universitet3 SCIENCE Faculty Management, SCIENCE Faculty Office, Faculty of Science, Københavns Universitet4 Geological Survey of Denmark and Greenland - GEUS5 SCIENCE Faculty Management, SCIENCE Faculty Office, Faculty of Science, Københavns Universitet6 Geography, Department of Geosciences and Natural Resource Management, Faculty of Science, Københavns Universitet
Normally it is believed that sea-level rise causes coastal barrier retreat. However, sea-level is only one of the parameters determining the long term coastal development of barrier coasts. Sediment supply is an equally important determinant and may overshadow the effects of sea-level rise. Conceptually this has been known for a long time but for the first time we can show the relative effect of these two parameters. We have studied three neighboring barrier islands in the Wadden Sea, and described their 3D morphological evolution during the last 8000 years. It appears that the barrier islands show quite different responses to sea-level rise. The southernmost island Rømø has survived 17 m of sea-level rise at the same position illustrating the control from sediment supply; whereas the northernmost island Skallingen has shifted its position several times during the same period indicating a much stronger component of sea-level control. The distance between the islands is only 50 km, and therefore our study shows that prediction of barrier development during a period of rising sea level may be more complicated than formerly believed.