HOLOCENE AEOLIAN ACTIVITY AND STORMINESS ON ANDØYA, NORTHERN NORWAY

The coastal areas of Norway are frequently visited by synoptic scale low-pressure systems following the North Atlantic storm track pattern. The systems vary in intensity, frequency and trajectory, and the most violent are regarded as extreme weather events causing widespread damages. In recent years, two devastating windstorms have struck the Norwegian coastline, namely Dagmar (25th December 2011) and Nina (10th January 2015). Both storms brought extremely high wind gusts (<65 m/s) and high storm surges, causing severe damage to infrastructure in the Nordic region. Such extraordinary storms are characterized by low probability and high impact, and further knowledge about past variability-, frequency- and intensity of such events are highly relevant in designing effective adaptation strategies for a changing climate.

Coastal dunes and cover sands are rather scarce in Norway. This is not due to low wind activity, but rather because of a lack in sediment sources (e.g. sand beaches) along the rugged coastline. Nevertheless, a few coastal dune systems are found along the coast – one of them being Sandhaugan situated on Andøya in northern Norway. Based on the assumption that periods with higher wind activity (more frequent high-energy wind events) cause increased deflation and sand drift further inland, we have investigated three sites downwind from the coastal dunes at Andøya. By combining geomorphological mapping, two independent lacustrine sediment records and a foredune stratigraphy, we have reconstructed a continuous history of the aeolian activity (and storminess) on Andøya back to the deglaciation period. Phases with high influx of sand are recorded around 11200–10300, ­6100, 4800, 4250, 3000–2000, 1850–1750, 1600–600, 450, 300 and 150 cal. yr BP.