2023/05/15 by Aakjær, Peter, Buch, Erik
#Baltic Sea #FOS: Natural sciences #Küsteningenieurwesen #L.A. Colding #Meeresregionen #Super-storm surge #hurricane
paper · doi:10.18171/1.092104
The super-storm surge (water levels above 3m) that hit the Danish and German coastlines in the western Baltic Sea on November 13, 1872, is the worst natural disaster in modern Danish history. The meteorological and oceanographic causes for this extreme event have been analysed using the relatively few observations from November 1872 combined with re-analysis outputs from modern operational forecasting models. Key findings for the days November 11-14, 1872, are: • The Baltic Sea was exposed to north-easterly storm to hurricane force winds • The extreme water levels were solely wind generated. • Theories of backwash of water from eastern Baltic or higher than normal water level in the Baltic Sea is refuted. The extraordinary water levels on 13 November 1872 can most likely be attributed to the length of the storm/hurricane. • The western Baltic Sea, in particular the Arkona Basin area, was exposed to 8-10 m waves. The combination of a super-storm surge and extreme waves caused severe damage along the Danish Baltic Sea coastlines. Around 90 people drowned in the Danish coastal areas, especially in the flat southern parts of the two islands of Lolland and Falster. Houses and local infrastructure were destroyed leaving thousands homeless the following winter. Additionally, an unknown number of sailors drowned when several hundred sailing ships shipwrecked during the storm. A nationwide collection of money to help the many victims was initiated and successfully implemented. Super-storm surges will inevitably hit the Baltic Sea again. A detailed high-water statistics, including historical surge registrations, reveal a return period of around 300 years for a 1872 size super-storm surge. In preparing for the next super-storm surge, it is, however, important to consider the sea level rise due to climate change. According to national authorities, the sea level in the Danish waters will rise around 0.5 m before 2100.