Measurement and Model Simulations of Hydrodynamic Parameters, Observations of Coastal Changes and Experiments with Indicator Sediments to Analyse the Impact of Storm St. Jude in October, 2013

The aim of the study is to analyse the meteorological parameters, hydrodynamic conditions and coastal changes caused by a severe European storm referred to as St. Jude (Christian). It crossed the Baltic Sea on 27–29 October 2013. At Cape Kelba in the west Estonian archipelago, wave parameters were measured by RDCP and simulated by two wave models. Shoreline and topographic changes were recorded before and after the storm by RTK-GPS device. Simultaneous experiments with painted sediments were carried out to analyse sediment transport patterns and wave impact on the nearshore sea bed. It was the most significant storm in Estonia since 2007 with wind gusts up to 33 m/s and local storm surge height 1.5 m. The measured significant wave height reached 3.4 m at the 5.5 m deep point near the geomorphic study site. Modelling study indicated some wave-current-surge interaction effects. The distal section of the Kelba Spit elongated by about 12 m, but only minor changes were registered in the proximal part of the spit. The painted sediments placed on the sea bed at depths from 2–6 m were swept up to 20 m towards the shore