Holocene relative sea-level changes in the eastern part of Pomeranian Bay and the Szczecin Lagoon, Southern Baltic Sea

Abstract

Sea-level changes of the Baltic Sea have been in the focus since the beginning of Baltic history studies. The main goal of the study is to reconstruct Holocene sea-level changes in the eastern part of Pomeranian Bay and the Szczecin Lagoon. For this purpose, 171 radiocarbon dates were used for the eastern part of Pomeranian Bay and 131 radiocarbon dates for the Szczecin Lagoon. The data allow reconstructing sea-level changes in the last 8500 years in the eastern part of Pomeranian Bay and 7500 years in the Szczecin Lagoon. The sea level 8500 yr b2k was ca. 16 m in Pomeranian Bay, while 7500 yr b2k in the Szczecin Lagoon, it was ca. 8 m below the present sea level. Initially, the fast sea-level rise (up to 9.0 mm/yr) slowed down about 6000 yr b2k to ca. 1.0 mm/yr. In the last 5000 years, the sea level rose at a rate of 0.5 mm/yr in both sites. Analysed data allow distinguishing an extreme event (or events) that disturbed a rather regular course of sea-level rise, which occurred between 7314 and 7022 yr b2k. The history of sea-level changes was similar in the eastern part of Pomeranian Bay and the Szczecin Lagoon despite differences in the geological structure of the pre-Quaternary bedrock and potential various trends in vertical crustal movements. Similarities to some other regions of the southern Baltic and the world ocean allow assuming that sea-level changes in the study area in the last 9000 years in general were eustatic in nature.

Driving forces and determinants of barrier coast evolution in the Holocene observed on the southern coast of the Baltic Sea

“…Global warming and the melting of ice sheets in Eurasia and North America caused a rapid sea level rise (Engelhart et al, 2015; Lambeck et al, 2014; Loveson and Nigam, 2019; Meijles et al, 2018; Sloss et al, 2007). Similar situation was recorded in the Baltic Sea area (Bennike and Jensen, 1998, 2011; Hoffmann et al, 2009; Sydor and Uścinowicz, 2022; Uścinowicz, 2003; Uścinowicz et al, 2021). In the study area, the first traces of marine influence date back to ca.…”

“…Based on the morphology and geological structure of the seabed derived from bathymetric maps, seismoacoustic profiles and cores (Dobracki and Zachowicz, 2007; Kramarska et al, 2016; Uścinowicz, 2003), the geological structure of the coast (Figures 7–9) and the sea-level curve (Figure 11) (Sydor and Uścinowicz, 2022), models of the barrier coast evolution during the Holocene in the Pomeranian Bay area were developed. When creating coast development models for the study area, it was assumed that hydro-meteorological conditions, including wind directions, longshore currents and wave climate, despite some climate oscillations, were essentially similar to those of today.…”

“…All radiocarbon dates used in this study (own and historical data) and methodology of their calibration were presented in a separate research paper (see Sydor and Uścinowicz, 2022).…”

“…7000 yr b2k was about 6–5 m lower than today. The rapid rise in sea level, that was up to 9 mm/yr, slowed down between 7000 and 5000 yr b2 k to about 2–1 mm/yr and thereafter slowly approached the current sea level with an average rate about 0.5 mm/yr (Sydor and Uścinowicz, 2022).…”

New insights into coastal processes in the southern Baltic Sea: relevance to modelling and future scenarios

“…Be tween 7000-5000 yr b2k the sea-level rise slowed down. Over the last 5000 years sea level has risen by ~2.5 m at an av er age rate ~0.5 mm/yr and the bar rier has slowly mi grated to its pres ent po si tion (Uoecinowicz et al, 2007(Uoecinowicz et al, , 2022Sydor and Uoecinowicz, 2022).…”