Storm flood impacts along the shores of micro-tidal inland seas: A morphological and sedimentological study of the Vesterlyng beach, the Belt Sea, Denmark

- Impacts of a large-scale storm flood along a micro-tidal inland sea are studied.
- Storm deposits include gravelly berms, wash-over fans, gravel flats and storm scarps.
- Storm berm crest height is a precise proxy of overwash level during a storm flood.
- Holocene beach-ridge systems reveal past storminess history.

The morphological and sedimentological impacts of an extreme storm event ('Bodil' in December 2013) were investigated at a mixed sand and gravel beach (Vesterlyng) in a micro-tidal environment along the Belt Sea, Denmark. The storm response was characteristic for mixed sand and gravel beaches: gravelly storm berms with sandy to gravelly washover fans were formed at the upper beach where swash processes dominated during extreme water levels in combination with overtopping and overwash. In addition, storm scarps and gravel flats were formed. The elevation of the storm berm crest was identical to a summation of the still-water level (1.60 m) in the Belt Sea during the storm flood and the wave run-up (0.75 m) at the shore. The crest of 2.35 m is therefore a precise measure of the storm flood level. This storm flood was classified as a large-scale extreme event. In a Holocene perspective it is suggested that storm berm (beach ridge) heights above contemporaneous sea level can be used as a proxy of past flood events along micro-tidal shores.