Baltica®, an International Journal on Geosciences, celebrates its 50th anniversary. As the Editor-in-Chief I congratulate Journal authors, readers, reviewers, Scientific Committee members for your excellent work. Let remind you that the Editorial Column once briefly reported how Baltica’s history remarkably changed during the semi–centenary.
On occasion of his 95th birthday, the German geologist and Professor Eugen Seibold (* May 15, 1918) is honoured for decades of active research, academic education and scientific management in marine geology as well as for his promotion of geoscientific research about the Baltic Sea. The first part on Professor Eugen Seibold deals with his scientific achievements, while the second part is a reprint of his 1965 pioneering article on the interaction between the Baltic Sea and the North Sea based on sedimentological studies from the Great Belt.
Keywords: Eugen Seibold; Marine geology; Salt water inflow; Great Belt; Baltic Sea
The Baltic, the model of a sea in the humid realm, is connected to the open ocean essentially through the Great Belt. Through it, dense saline deep water penetrates inward, light surface water flows outword. A density discontinuity layer separates the two types.
There are two long-term causes of continuing transgression in the south Baltic Sea – the glacioisostatic uplift in the Bothnian Bay and the eustatic sea level rise. At a regional scale the cliff sediments and the seasonal climate conditions during the year are significant factors controlling cliff erosion. The erosion of cliffs of glacial sediments has been investigated on Wolin Island, located in the Baltic Sea in northwest Poland. Previous monitoring of morphological processes on Wolin Island provides a baseline for further detailed studies of cliff erosion. In long-term field investigations a mean cliff retreat of 0.14 m a-1 was measured during the last 30 years. In this study a high-resolution terrestrial laser scanner was used for monitoring cliff retreat at two test sites. In a four-month interval and an annual interval both sites were scanned and total cliff erosion of 0.090 m a-1 and 0.043 m a-1 with volume changes of 434.7 m³ and 888.7 m³, respectively, was measured. The cliff erosion is significantly higher in the colder and more humid periods. Cliff stabilization occurs in conditions of low and average rainfall and above-average temperatures.
Keywords: Terrestrial laser scanning; Cliff coast erosion; Polish Baltic Sea coast
Underwater noise is an issue with rising importance in the Klaipėda Strait, as man-made activity grows in this area. The article presents methods and results of the first attempt to measure underwater noise in the Klaipėda Strait connecting the Baltic Sea and the Curonian Lagoon. Emphasis is placed on the background underwater noise in the area, where vessels traffic makes its general contribution to it. Dredging and vibro-pile driving noise have been studied as contributors to the background noise as well. Comparison of background noise in the Klaipėda Strait and an unaffected Curonian Lagoon area is given. Possible impacts of underwater noise on migrating fish species are shortly discussed.
Keywords: Acoustics; Underwater noise; Pile driving; Dredging; Ship traffic; Klaipėda Strait; Lithuanian Baltic Sea coast
This study concerns on spatial and temporal effects of surface parameters on boundary layer meteorological fields in urban territories. Selected parameters (2-metre temperature, precipitation amount and intensity, wind speed) are important for evaluating air pollution dispersion. Study is done using Enviro-HIRLAM numerical weather prediction model with the modifications of surface parameters to reflect changes due to urbanization. The modifications were made to parameters that are directly influenced by urbanization: surface roughness, albedo and anthropogenic heat flux. Case study consists of three different dates with different conditions and two different modelling domains. Overall, nine simulation runs were done including the control ones. Comparison of control and modified model runs was used for evaluation of effects. Differences of wind speed and temperature between control and modified runs were detected and in some cases, they reach up to 1.4 °C and 2.7 m/s. In addition, spatial differences in precipitation meteorological field were observed.
Keywords: Urban territories; Boundary layer meteorology; Air pollution dispersion; Numerical weather prediction; Physical geography; Vilnius city; Lithuania
During the last decades many studies were concentrated on the North Lithuanian ice marginal ridge of the Last Glaciation (Late Nemunas, Late Weichselian). The North Lithuanian ice marginal ridge or so–called Linkuva ridge was formed by Žiemgala Ice Lobe that advanced at the end of the glaciation through the Gulf of Riga. This ridge is considered as a boundary of glacier limit during the North Lithuanian recessional phase of the Late Nemunas Baltija stage. Linkuva ridge is stretching about 130 km as a bow-shaped ridge and is marking the boundary of an active ice lobe. The thickness of Quaternary deposits is 10–12 meters on the average but varies from 1.0 to 39.0 meters: the thinnest Quaternary cover is characteristic for river valleys, whereas the thickest one is related with the highest altitudes of the present topography or with rare palaeoincisions of the sub–Quaternary surface. Pleistocene strata are subdivided to three till complexes in some places separated by inter–till sediments.
Keywords: End moraine; Kame terrace; Massive clay; Glaciolacustrine plain; Ice–dammed lake; Drumlins; Till; North Lithuania
Two sediment cores have been obtained from the southern and eastern parts of the Gdansk Basin for lithological, geochemical and diatom analysis. The data revealed provides information about environmental changes during the transition of the Ancylus Lake to the Litorina Sea stages. The Ancylus Lake transgression and regression phases have been well traced in the diatom flora of the shallower, eastern slope of the Gdansk Depression, whereas mentioned water level changes have not been detected in the deepwater (southern) part of the basin. The Litorina Sea has been clearly defined according to geochemical, lithological and diatom analysis. The Initial Litorina Sea transition was observed as gradually increasing numbers of brackish water diatoms and higher contents of Corg and N in the sediments, when saline water influx reached the basin before 7600±184 cal. yr BP.
Keywords: Diatoms; Geochemistry; Ancylus Lake; Litorina Sea; Holocene; Gdansk Basin; Baltic Sea
The study concerns the analysis of temporal and spatial variability of thermal and precipitation conditions at the Polish Baltic coastal zone in the second half of the twentieth century and the first decade of the twenty–first century. The paper also presents its annual and daily extreme values of air temperature and precipitation. The study area includes the Polish coast of the Baltic Sea at which long–term measurements and observations of weather conditions have been performed within the national meteorological services at seven Baltic coastal stations. Their daily data of air temperature and precipitation taken from the measuring period of 1966–2009 were used in the study. For each meteorological station was set thresholds of annual average air temperature and annual total precipitation. Temporal variability of air temperature was determined by the thermal classification made by Lorenc (1998). Temporal variability of precipitation was determined by the precipitation classification made by Kaczorowska (1998).
Keywords: Thermal conditions; Precipitation conditions; Extreme weather events; Polish Baltic Sea shore
Bottom sediments of Lake Peipsi proper were mapped in the 1970s’ from the research vessel but for technical reasons near shore areas were not investigated. The present work is the first attempt to fill this gap. Based on the surface sediment mapping of the whole lake basin, we identified 11 key areas of the littoral zone and provided a detailed survey of the sediments. By the grain-size, the surface sediment samples can be separated into three groups: coarse-grained (predominantly sands in the near shore areas and in the southern part of the lake), fine-grained (mainly silts) and clayey sands, both in the central deeper part of the lake within the 8 m depth contour. Because of a complicated system of currents, the granulometry of deposits shows distinct spatial distribution. Long-term observations have shown that the water level in Lake Peipsi changes cyclically, i.e. years with a low water level alternate with years with a high water level. This phenomenon causes fast erosion in some years and exuberant growth of reed and bulrush and accumulation of fine material in the coastal zone in other years. Water-level fluctuations affect the sediment characteristics and aquatic vegetation assemblages and have influence on the land use, fishery and recreation.
Keywords: Near shore sediment; Littoral zone; Shore types; Erosion and accumulation; Protection of the coasts; Lake Peipsi
The article deals with the hypsometric assessment of the pre-last Glaciation (Late Saalian) topography which represents a glaciogenic landforms of the Medininkai stadial in south-east Lithuania. The study area belongs to two elevations as orographic units: the Lyda Plateau and the Ašmena Upland. Cartometric topography analysis has been performed in nine reference areas based on large-scale (1:25 000) cartographic maps. The topographic relative height varies from 11.8 m to 30.6 m and depends on the surface altitude (correlation coefficient R = 0.85). The correlation links between the base and top surfaces (R = 0.74–0.92), concave-convex graph of hypsometric curves and value of hypsographic integrals (0.45–0.58) indicate that in general pre-last Glaciation topography of south-east Lithuania at the present stays in equilibrium conditions.
Keywords: Hypsometric analysis; Late Saalian; pre-last Glaciation; Middle Pleistocene; south-east Lithuania
The results of testing (hindcast) an operational hydrodynamic model HIROMB_LT for Lithuania’s coastal zone are presented and analysed in this paper. A model is developed using the program code of an operational hydrodynamic model of the Baltic Sea HIROMB (Swedish Meteorological and Hydrological Institute). The model grid (horizontal resolution 300m, vertical resolution 25 layers) covers the Baltic Sea coastal area until the Gdansk Bay in the West and Latvian border in the North and the Curonian Lagoon. The model simulated water levels, surface water temperature surface water salinity and ice cover variables were tested against measurements for the year 2009. The model shows satisfactory performance on water level and temperature and rather weak performance on salinity at stations where good reproduction of the mixing of fresh and saline water is critical (Juodkrantėand Klaipėa seaside stations). The model performance on ice thickness is still problematic because of too coarse spatial resolution of westerly winds. Despite of these shortcomings, the model can be used for operational forecasts already; however, data assimilation may be necessary for salinity and ice thickness.
Keywords: Operational model; Validation; Baltic Sea; Coastal area; Lithuania