Die Küste, 74 ICCE (2008), 31-44 
33 
G«od«tc Datum WGS 84 
Map ProfOon Mfcto» (54*N) 
d«,o*.V."Vl8lan«s 
d«roo08«nd 
Fig. 2: Seabed Morphology of the German Bight (North Sea) including localities mentioned in the 
text. (Source: CONTIS [BSH]) 
sand ridges are 2-5 m in height and occur in water depth between 12-18 m MSL. The core of 
such ridges is at least of early Atlantic age, i. e. approx. 7,500 years Before Present (Laban 
and Schuttenhelm, 1981). These morphological features exhibit a pronounced dynamic be 
haviour having cross-shore migration rates of between 100 and 200 m a _l at their maximum 
(Antia, 1996). 
Borkum Riffgrund extends towards the Dutch offshore waters and represents a relict of 
a former Pleistocene terminal moraine. Below approx. 20 m MSL, the seafloor of the western 
German Bight is comparatively flat and smooth except some patchy areas showing current 
ripples. Dogger Bank (Tail’s End) dominates the seabed morphology at the north-western 
end of the German North Sea sector. 
Because the North Sea was not covered by ice during the last glacial period, the seafloor 
underwent one regressional and two transgressional phases which shaped and levelled the 
sediment surface (Figge, 1981). Accordingly, the sediment distribution pattern in the Ger 
man Bight (Fig. 3) to a high degree reflects reworking processes acting since the retreat of the 
Saalian ice shield. On one hand, relict sediments ranging from fractions of coarse sand to 
boulders usually cover glacial till and protect the sea floor against further abrasion. On the 
other hand, fractions of fine to medium sand are almost permanently reworked by wave- 
induced and tidal currents. 
The thickness of the mobile sediment cover along the German North Sea coast down to 
a depth of 20 m below MSL shows three distinct zones which are running more or less 
parallel to the coastline (Fig. 4). Seaward of the Wadden Sea in shallow water depths between