Abstract The western ablation zone of the Greenland ice sheet is darker than the surrounding ice, because a higher amount of fine-grained particles, known as a cryoconite, occur. To date, biotic cryoconite components have gained a lot of attention, in contrast with mineral components, which have been studied to a limited extent. In this study, fine-grained quartz grains from the cryoconite holes of the Russell Glacier, southwest Greenland are, therefore, examined. Authors use scanning electron microscope to elucidate shape, surface character and origin of these mineral quartz particles. Triangular-faceted, sharp-edged grains dominate in most of the investigated samples, and originate from local sources, where grain-to-grain contact in the ice prevail. Grains with smooth corners and edges result from chemical weathering in meltwater of alkaline pH, in which quartz solubility significantly increases. However, part of these rounded grains is due to mechanical abrasion by wind action. Postsedimentary frost action is visible through grains entirely or partially covered by scaly-grained encrustation. Local processes and sources are largely responsible for aforementioned grain outlines. However, few grains with bulbous silica precipitation argue for a dry and warm climate, and distant, out-of-Greenland origin.
Keywords • glacial • periglacial • weathered • aeolian • quartz grain • SEM
Abstract. This study focuses on time scales and spatial variations of interrelations between average weather conditions and sea surface temperature (SST), and long-term changes in the SST in south-eastern Baltic Sea. The analysis relies on SST samples measured in situ four times a year in up to 17 open sea monitoring stations in Lithuanian waters in 1960–2015. A joint application of non-metric multi-dimensional scaling and cluster analysis reveals four distinct SST regimes and associated sub-regions in the study area. The increase in SST has occurred during both winter and summer seasons in 1960–2015 whereas the switch from relatively warm summer to colder autumn temperatures has been shifted by 4–6 weeks over this time in all sub-regions. The annual average air temperature and SST have increased by 0.03°C yr–1 and 0.02°C yr–1, respectively, from 1960 till 2015. These data are compared with air temperatures measured in coastal meteorological stations and averaged over time intervals from 1 to 9 weeks. Statistically significant positive correlation exists between the SST and the average air temperature. This correlation is strongest for the averaging interval of 35 days.
Keywords • sea monitoring • sea sub-regions • sea surface temperature • sea-air interactions • climate change
Abstract A hurricane known as Ervin or Gudrun travelled over Latvia in 8–9 January, 2005. As a result of severe SW and W winds, as well as lack of sea ice, clearly pronounced changes in the distribution of coastal sediment has been induced. Cross-shore profile leveling at various time instants was used to obtain quantitative estimates of the amount of accumulated sediments. The total volume of sediments eroded from the subaerial part of coastal slope reached 0.8 million m3. This paper represents assessment of consequent changes and coastal slope “rebuilding” success after this storm event. The data indicates lack of significant overall net loss of subaerial sediment volume along the most part of the eastern coast of the Gulf of Riga. Significant primary dune growth and beach accumulation is mostly limited to southernmost part of assessed coastal stretch. Total volume of fine sediments in beach and primary dunes still is 5 % lower than before erosion event of 2005. Erosion vulnerability and total length of coastal sections that are expected to be a subject to future coastal retreat is increasing.
Keywords • Gulf of Riga • coastal processes • storms • sediment balance • beach • retreat
Abstract The study looked at the temporal and spatial variability of dune erosion in the Polish Baltic coastal zone in the period 1972–2008. The dynamics of coastal dune erosion in the area are presented in relationship to the main hydro-meteorological factors: storm surges and types of atmospheric circulation. The greatest destruction of the coastal dunes in Poland was observed on sandbar sections, where the erosion was over 100,000 m3 per 1 km, causing dune baseline retreat by several tens of meters. The main causes of this considerable coastal erosion are the sudden rise of the sea level and the waves during extreme storm surges, when the loss of dune sediment across the entire Polish Baltic Sea coastal zone can reach about 400,000 m3. These extremely erosive storm surges are particularly generated by cyclonic atmospheric circulation, which accounts for more than 52% of such surges from the north-west, north, and west. It was also found that sea level increases of more than 1 meter (about 602 cm) above the mean sea level (about 500 cm) can result in significant erosion of coastal dunes in Poland (>100,000 m3). However, there is a relationship between the intensity of the dune erosion and sea level. The results of the present study could be applied to studies of Baltic coastal dunes functioning in the lagoon-spit coastline, especially in the stretch from Estonia to Germany.
Keywords • dune erosion • Baltic coast • extreme storms • threshold values
Keywords • Vistula Lagoon • water balance • water exchange • water supply • water outflow • components of water balance
Abstract The objective of the article is to give a comprehensive assessment of the impact that physical geographical factors of the coastal environment have on the South Baltic seaside resorts in the way it is reflected in planning documents (comprehensive plans, regional and tourism development strategies) of South Baltic seaside territorial entities. The seaside resorts and the adjacent coastal protected nature areas, particularly coastal national parks and UNESCO biosphere reserves, are the main focus of this study. The contents of 141 valid documents of spatial planning, management and development has been analysed. The studied comprehensive development plans, tourism strategies and other documents demonstrate that virtually all seaside municipalities in the South Baltic Region express a strong concern in increasing risk of coastal erosion and sea level rise related to the global climate change.
Keywords • physical factors • planning documents • seaside resorts