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Featured Application: Geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts' conditions. Sandy coasts are one of the most dynamic spheres; continuously changing due to natural processes (severe weather and rising water levels) and human activities (coastal protection or port construction). Coastal geodynamic processes lead to beach sediment erosion or accumulation. The coast's dynamic tendencies determine the changes in the volume of beach sediments; grain size; mineralogical; and geochemical composition of sediments. In addition to lithological and mineralogical analysis of sediments, geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts' conditions. The study aims to assess trace metals' temporal and spatial distribution determined in the sandy beach sediments along the south-eastern Baltic Sea coast (Lithuania) during 2011–2018. The Lithuanian seacoast is divided into two parts: mainland and spit coast. Our results revealed that the dominant group of elements on the mainland includes Ca–Mg–Mn–Ti and on the Curonian Spit Fe–Pb–As–Co–Cr–Ni–Al, which remain unchanged during the years. The analysis included additional parameters such as beach volume, grain size and sorting, and heavy mineral concentration on the beach. The spatial analysis of trace elements indicated that the trace metal content depends on the coastal processes, but it differs in the mainland and spit sea coast. We identified a higher concentration of trace metals in the erosion-dominated areas in all analysed years on the mainland coast. On the spit coast, the trace metal concentration increased in areas associated with relict coarse sand and where the loading of sediments was active on the beach due to the northward along-shore transport. [ABSTRACT FROM AUTHOR]

An analysis of the dynamics of wind velocity along the Baltic coast of Lithuania is presented, based on data collected during field experiments in the summer, fall and winter of 1999.2001 and 2007.2009 at several sites (Būtingė, .aipiai, Smiltynė, Juodkrantė, Pervalka and Nida). The locations were chosen in order to encompass a wide spectrum of beach and dune ridge morphology. The relationship between wind velocity dynamics and coastal morphology was established, based on measurements of the slope angle, height and shape of the dune crest, as well as measurements of the morphology of the area behind the foredune ridge. On the basis of a comparison of near-surface wind velocity patterns, shear velocity (U*) and surface roughness length (z0) were calculated. It was determined that U* decreases from the middle of the beach towards the foredune toe, then increases towards the crest of the foredune and decreases down the lee slope. A direct correlation exists between U* and the stoss slope inclination, and the relative height of the foredune. Surface roughness length also increases from the beach towards the foredune crest. [ABSTRACT FROM AUTHOR]

The investigations were carried out in order to evaluate change of the beaches profile during the period 1993-2008 and to elucidate main trends of the coastal dynamics. Morphometric indicators (beach width, height and inclination) were measured every year during the period 1993-2008 in 70 measuring stations located along the coastline. It was determined that the dynamic shoreline of the mainland during 1993-2008 receded by 10.2 m and the dynamic shoreline of the Curonian Spit advanced into the sea by 8.3 m. The different morphometric beach indicators changed to varying extents over the period 1993-2008, but comparison of values for 1993 and 2008 showed that those changes were small. The average beach width increased by 1.2 m on the mainland coast and by 0.5 m on the Curonian Spit coast. The average beach height also increased negligibly: by 0.5 m on the mainland coast and by 0.1 m on the Curonian Spit coast. The average beach slope inclination increased by 0.012 (from 0.065 to 0.077) on the mainland coast and by 0.005 (from 0.073 to 0.078) on the Curonian Spit coast. The measurements show that, despite being the most dynamic elements in the coastal system, these beaches managed to retain their morphometric indicators almost unchanged during the period of observation. [ABSTRACT FROM AUTHOR]

Investigations were carried out in order to evaluate changes of the beach profile during the period 1993-2008 and to elucidate the main trends of coastal dynamics. The morphometric indicators (beach width, height and inclination) were measured every year during the study period in 70 measuring stations located along the coastline. It was determined that in 1993-2008 the dynamic shoreline of the mainland receded by 10.2 m and the dynamic shoreline of the Curonian Spit advanced into the sea by 8.3 m. Different morphometric beach indicators changed to varying extents over the period, but a comparison of their values for 1993 and 2008 showed that these changes were small. The average beach width increased by 1.2 m on the mainland coast and by 0.5 m on the Curonian Spit coast. The average beach height also increased negligibly: by 0.5 m on the mainland coast and 0.1 m on the Curonian Spit coast. The average beach slope inclination increased by 0.012 m (from 0.065 to 0.077) on the mainland coast and 0.005 m (from 0.073 to 0.078) on the Curonian Spit coast. The measurements show that, despite being the most dynamic elements in the coastal system, these beaches managed to retain their morphometric indicators almost unchanged during the period of observation. In the coastal sectors with the prevailing accretion processes, beach widening provides favourable conditions for wind transportation of larger sand masses (due to the increased sediment volume in a beach and wind fetch distance) and the formation of a dune ridge closer to the shoreline. Due to dune ridge transgression, the beach morphometric indicators remain only slightly changed. In the coastal sectors with the prevailing erosion processes, the narrowing of beaches allows the waves to erode the dune ridge. Part of material from the regressing dune ridge is accumulated at the beach, resulting in the recovery of beach profile. In such a way, the beach profile retains quasi-stability both in a coast dominated by accretion processes and in a coast with the prevailing erosion processes. Actually, if the essential factors forming the beach -- the wave energy and the composition of beach deposits -- do not change, the beach profile tries to return into equilibrium with the forming factors. The quasi-stability of beaches is revealed only by analysing the average long-term measuring data over long coastal sectors (in this case, the Lithuanian mainland coast and the coast of the Curonian Spit). Analysis of the long-term dynamics of the morphometric indicators of beaches in shorter coastal sectors or in an individual profile has shown that they may vary considerably due to rhythmic topography and rip cells. Changes of morphometric indicators were most significant in the coastal sectors that have a greater morpholithological diversity and anthropogenic loads. This is especially evident on the mainland coast. The measured morphometric indicators are of great value for planning the coastal infrastructure and adaptation to climatic variations. [ABSTRACT FROM AUTHOR]

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The morphometric parameters of the submarine shore slope of the Lithuanian part of the Curonian Spit (Kuršių Nerija) were analysed: width and inclination of the submarine slope, the width of the nearshore zone, its curvature, inclination, depth at the beginning, depth above the outer bar and the number of bars; the widtb and inclination of the offshore. Alongshore dynamic patterns of these parameters and their interdependence were determined. The data analysis revealed that most of parameters vary depending on the changes of submarine slope angle. Based on the data on submarine shore slope parameters and wave transformation patterns the variations of height of the breakers forming along the investigated shore sector at the marine boundary of the nearshore were determined. Calculation results showed that the height of breakers followed an increasing pattern from north to south along the Curonian Spit. [ABSTRACT FROM AUTHOR]

Beach-foredune sediment exchange maintains a coastal system's stability. Sea level fluctuation is one of the most important factors that modifies the beach and foredune sediment budget. This study aims to assess beach and foredune sand budget changes depending on sea level fluctuations. On the basis of annual measurements of cross-shore profiles on the Curonian Spit in Lithuania, the sediment volumes on the beach and foredune and their changes between 2002 and 2019 were calculated. The sea level fluctuations were examined in parallel. The obtained data revealed that in the case of a sand surplus, a relatively low sea level rise does not have a significant impact on the development of a foredune (and a minimal impact on a beach) on a decadal time-scale. Short-term sea level fluctuations are reflected in year-to-year variability in a beach sediment budget. However, no significant relationship between year-to-year variability in sea level fluctuation and the foredune sediment budget has yet been identified, nor is there a reliable year-to-year variability relationship between the foredune and beach sediment budget. The foredune sediment budget remained positive both through an increase and a reduction in the sediment volume on the beach. [ABSTRACT FROM AUTHOR]