Analyses of high-resolution multibeam and sub-bottom profiling data, acquired during marine geological field cruises between 2017 and 2019 in the eastern Gulf of Finland (Baltic Sea), enabled the detailed mapping of Quaternary deposits, and revealed diverse submerged glacial and post-glacial landforms (e.g. streamlined moraine ridges, large retreat moraine ridges, De Geer moraines and kettle holes). The morphology of these glacial features provides evidence of the ice-sheet retreat direction and rate throughout the deglaciation of the region, which occurred between 13.8 and 13.3 ka BP (Pandivere­­–Neva Stage) and 12.25 ka BP (Salpausselkä I Stage). Analysis of sub-bottom profiling, supported by piston long-core sampling, indicates periods of bottom erosion/non-deposition during the Holocene caused by relative water-level regressions. Significant negative relief features are also observed in the area for the first time. These linear and curved V-shaped furrows are several kilometres long and 5 m deep, and are tentatively ascribed to bottom current and gas-seepage processes.

The results of both onshore and offshore monitoring of the coastal zone in the Russian Baltic reveal the high intensity and recent acceleration of coastal dynamics caused by an increasing frequency of extreme hydrodynamic events and anthropogenic impacts on the diverse geology. Stable coasts dominate in the eastern Gulf of Finland, but the local rate of shoreline recession is up to 2.0 m a−1, reaching 5 m in one extreme storm event. The coastal zone of the Kaliningrad area is diverse. The western coast of the Sambia Peninsula is controlled by anthropogenic influences linked to the exploitation of geological resources. The beaches advance when the supply of artificial sediments from opencast amber mines increases, whereas the shoreline retreat reaches 10–20 m a−1 when the input is interrupted. Active landslides and beach degradation dominate along the northern coast of the Sambia Peninsula. Large areas of pre-Quaternary deposits, outcrops and boulders in the nearshore provide evidence of sediment deficiency offshore. The coastal geological hazards are dependent on climate. A comprehensive understanding of the main trends in climate change is important for predicting and mitigating future damage to the coastal infrastructure and for selecting adaptation strategies.Thematic collection: This article is part of the Mapping the Geology and Topography of the European Seas (EMODnet) collection available at: https://www.lyellcollection.org/cc/EMODnet

The detailed environmental survey of the coastal zone of the Kaliningrad Region northern coast was carried out. The pollutants distribution in the silty clay fraction and calculation of ecological indexes allowed the evaluation of distribution of potentially harmful elements (PHEs). The sources of pollution in the most intensively used areas were identified, and transit and accumulation zones were allocated. A large area of anomalous content of PHEs was revealed on the underwater coastal slope of the Curonian Spit National Park, which is situated far from the sources of pollution. The alongshore bed load transport provides the contamination of the underwater slope whereas the beaches are less exposed to pollution.