808 Reprinted from Coastal Dynamics ´01 American Society of Civil Engineers Proceedings of the Conference Held June 11-15, 2001, Lund, Sweden SEDIMENT REDEPOSITION IN NEARSHORE AREAS - EXAMPLES FROM THE BALTIC SEA Klaus Schwarzer 1 , Markus Diesing 2 Abstract: Investigations of sediment dynamics and geomorphological changes on seasonal and annual scales have been carried out in two different sandy nearshore areas of the southern Baltic Sea. A new method called ‘tracer stick method’ was applied to collect data about erosion and accumulation to an accuracy of centimeters. On a seasonal basis there is a geographical variation of maximum erosion and deposition values, with the zone of maximum mobility shifting towards offshore during the stormy winter period. At both investigated areas the high sediment mobility does not automatically result in conspicuous morphological changes. INTRODUCTION Wave energy transferred into nearshore zones is the main driving force inducing on- /offshore as well as longshore currents, leading to sediment mobility which results in short and long term erosion, redeposition and accumulation. Knowledge about the quantity of redeposition is essential to estimate sedimentological and morphological coastline evolution as a result of wave energy input. This knowledge also supports the understanding of the behavior of nearshore zones as transitional and storage areas for nutrients and harmful substances (e.g. heavy metals). Investigations of short term (seasons, annual cycles) redeposition values carried out in two different nearshore regions of the southwestern Baltic Sea (Fig. 1) allow insight into sediment dynamics in the inner part of those zones. 1) Senior Research Scientist, Institute of Geosciences, Christian-Albrechts-University of Kiel, Olshausenstr. 40-60, 24098 Kiel, Germany, kschwarzer@corelab.uni-kiel.de 2 ) Scientist, Institute of Geosciences, Christian-Albrechts-University of Kiel, Olshausenstr. 40-60, 24098 Kiel, Germany, mdiesing@corelab.uni-kiel.de