Field observations on hydrodynamic and coastal geomorphic processes off Harilaid Peninsula (Baltic Sea) in winter and spring 2006–2007

摘要: Abstract Investigations of multi-layer current regime, variations in sea level and wave parameters using a bottom-mounted RDCP (Recording Doppler Current Profiler) during 20 December 2006–23 May 2007 were integrated with surveys on changes shorelines contours beach ridges at nearby Harilaid Peninsula (Saaremaa Island). A W-storm maximum average wind speed 23 m s−1 occurred 14–15 January an accompanying rise least 100 cm significant height 3.2 m the 14 m deep mooring site. It appeared that practically tideless Estonian coastal waters, Doppler-based “vertical velocity” measurements reflect mainly site-dependent equilibrium between resuspension sedimentation. The site, 1.5 km off Kelba Spit Harilaid, was located accumulation zone, where downward fluxes dominated fine sand settled. As result storms April, distal part accumulative gravel spit advanced by 50 m, whereas 30–50 m retreat shoreline western northern parts Cape Kiipsaare. location shows development occurs through relatively short-period but infrequent storm events, roughly 2–3 times each decade.