Program and Agenda

Abstract

LARGE-SCALE COASTAL IMPACT INDUCED BY A CATASTROPHIC STORM

Catastrophic storms and storm surges induce rapid and substantial changes along sandy barrier coasts, potentially causing severe environmental and economic damage. Coastal impacts of modern storms are associated with washover deposition, dune erosion, barrier breaching, and coastline and shoreface erosion. Little is however known about the impact of major storms and their post-storm coastal recovery on geologic and historic evolution of barrier systems. We apply high-resolution optically stimulated luminescence dating on a barrier system in the Wadden Sea (Denmark) and show that 5 to 8 meters of marine sand accumulated in an aggrading-prograding shoal and on a prograding shoreface during and within 3 to 4 decades (“healing phase”) after the most destructive storm documented for the Wadden Sea. Furthermore, we show that the impact of this storm caused large-scale shoreline erosion and barrier breaching. Our results demonstrate that violent, millennial-scale storms can trigger significant large-scale and long-term changes on barrier coasts, and that coastal changes assumed to take place over centuries or even millennia may occur in association with a single extreme storm event.

Authors

Fruergaard, M., University of Copenhagen, Denmark, mif@geo.ku.dk

Andersen, T. J., University of Copenhagen, Denmark, tja@geo.ku.dk

Johannessen, P. N., Geological Survey of Denmark and Greenland - GEUS, Denmark, pjo@geus.dk

Nielsen, L. H., Geological Survey of Denmark and Greenland - GEUS, Denmark, lhn@geus.dk

Pejrup, M., University of Copenhagen, Denmark, mp@geo.ku.dk

Details

Oral presentation

Session #:082
Date: 2/25/2014
Time: 08:45
Location: 312

Presentation is given by student: No