Morpholithodynamic conditions of the tip of the Hel Peninsula, the Baltic Sea

2015 ◽  
Vol 44 (2) ◽  
Author(s):  
Maria Rucińska-Zjadacz ◽  
Stanisław Rudowski
Keyword(s):  
Deep Water ◽  
General Nature ◽  
Base Line ◽  
The Baltic Sea ◽  
Sediment Samples ◽  
The Baltic ◽  
Line Positions ◽  
Water Depths ◽  
Beach Profiling

AbstractThe Hel Peninsula is a 35 km long spit that extends into water depths of almost 60 m. Unlike most sandy barriers, the distal end of the Hel Peninsula is prograding into the deep water. This affects unique conditions for the evolution of this section of the Peninsula. The aim of this study is to determine the morpholithodynamic changes on the tip of the Hel Peninsula. Shore studies were performed in 2006-2008 and 2012. Measurements included: beach profiling, determination of shoreline and dune base line positions, and collection of sediment samples. The different nature of the eastern, central and western part of the Hel tip is evident. The eastern part is accumulative, the central part is variable with the general nature of strong and differently directed redeposition and accumulative periods, while the western part is highly erosive.

Geodetic determination of the surface topography of the Baltic Sea

1997 ◽  
Vol 20 (4) ◽  
pp. 307-316 ◽  
Author(s):  
Juhani Kakkuri ◽  
Markku Poutanen
Keyword(s):  
Baltic Sea ◽  
Surface Topography ◽  
The Baltic Sea ◽  
The Baltic

scholarly journals Ships and their timber source as indicators of connections between regions

AmS-Skrifter ◽  
2020 ◽  
pp. 133-143
Author(s):  
Aoife Daly
Keyword(s):  
Western Europe ◽  
The Baltic Sea ◽  
The North ◽  
Baltic Coast ◽  
Art Objects ◽  
The North Sea ◽  
The Baltic ◽  
North And South ◽  
North Western

The precise dating and determination of the source of timbers in shipwrecks found around the coasts of the North Sea and the Baltic Sea, through dendrochronology allows us to see connections between north and  south, east and west throughout the region and to a high chronological precision. In this paper we take a look at results of recent analyses of timber from ships, and timber and barrel cargoes, to try to draw a chronological picture, from the twelfth to seventeenth centuries, of links between regions, through transport in oak ships and trade of timber. Archaeological finds of oak from timber cargos in shipwrecks and fine art objects (painted panels and sculpture) show the extent to which timber was shipped from Hanseatic towns along the southern Baltic coast, to western and north-western Europe.

CLOUDINESS IN THE POLISH COASTAL ZONE OF THE BALTIC SEA AND CONDITIONS FOR RECREATION

2017 ◽  
Vol 45 ◽  
pp. 51-63
Author(s):  
Czesław Koźmiński ◽  
Bożena Michalska
Keyword(s):  
Baltic Sea ◽  
Coastal Zone ◽  
Temporal Variations ◽  
The Baltic Sea ◽  
Summer Half ◽  
The Mean ◽  
Bioclimatic Conditions ◽  
The Baltic ◽  
Time Specific

Purpose. Determination of size, variability and gradient of cloudiness on the Polish coast of the Baltic sea during the summer half-year and identification of zones with variable suitability for recreation due to cloudiness. Method. The research is based on daily values of cloudiness in the warm half-year (April-September) recorded on a scale from 0 to 8 octants, obtained from six meteorological stations located on the Polish coast of the Baltic sea during the period 2000–2016. Methods of linear regression were used in the analysis of temporal variations of cumulative monthly deviations in cloudiness for consecutive years from the mean multiannual value. In terms of recreational suitability, days were categorised into four classes according to cloudiness. Three zones of varying conditions for recreation were identified. Results. The essential characteristic of cloudiness on the Polish coast of the Baltic sea is very high variability from one day to another and the resulting change in the value of solar radiation, which, consequently affects bioclimatic stimuli. Cumulative deviations of monthly cloudiness values from the mean multiannual value show a decrease in cloudiness in April, June and July, and an increase in the remaining months of the warm half-year. It is possible to distinguish three periods regarding increased frequency of clear and moderately clear weather lasting continuously for at least 3 and 5 days on the coastal zone in summer. The Polish coast of the Baltic sea is marked by three zones of varying conditions for recreation due to cloudiness in the summer – moderately favourable, favourable and very favourable. Research and conclusion limitations. Lack of access to time-specific results of cloudiness measurement. Practical implications. The results obtained in the course of this research may be used by individuals as well as the organizers of their stays, and for the purpose of characterisation of bioclimatic conditions of the coast. Originality. In view of the recent climatic changes recorded over the last 30 years, the present research demonstrates the current cloudiness level on the Polish coast of the Baltic sea. Type of research. Presentation of the results of empirical research.

Mapping seagrass and water depths using Sentinel-2

2020 ◽  
Author(s):  
Katja Kuhwald ◽  
Philipp Held ◽  
Florian Gausepohl ◽  
Jens Schneider von Deimling ◽  
Natascha Oppelt
Keyword(s):  
Remote Sensing ◽  
Baltic Sea ◽  
Atmospheric Correction ◽  
The Baltic Sea ◽  
Seagrass Meadows ◽  
Spatial Coverage ◽  
Acoustic Methods ◽  
The Baltic ◽  
Water Depths ◽  
Sentinel 2

<p>Seagrass meadows cover large benthic areas of the Baltic Sea, but eutrophication and climate change imply declining seagrass coverage. Apart from acoustic methods and traditional diver mappings, optical remote sensing techniques allow for mapping seagrass. Optical satellite analyses of seagrass mapping may supplement acoustic methods in shallow coastal waters with observations that are more frequent and have a larger spatial coverage.</p><p>In the clear Greek Mediterranean Sea, Sentinel-2 was already applied successfully to detect bathymetry and seagrass meadows. We are now testing whether Sentinel-2 data are also suitable for analysing the sublittoral in the turbid waters of the Baltic Sea. We focus on an extensive shallow water area near Kiel/Germany. Based on Sentinel-2 data, we analyse water depth and differentiate between seagrass covered and bare sandy ground. We derive these parameters using empirical and process-based models. First results show that Sentinel-2 allows to determine water depths up to 4 m (RMSE ~ 0.2 m). Comparisons with LiDAR water depths show that inaccuracies increase in overgrown areas. Our study also shows that the atmospheric correction algorithm influences sublittoral ground mappings with Sentinel-2 data. For instance, the absolute water depths of the process-based modelling differ up to 2.5 m on average depending on the atmospheric correction algorithm (ACOLITE, Sen2Cor, iCOR).</p><p>Comparing Sentinel-2 seagrass classifications with diver mappings and aerial imagery emphasises that empiric approaches provide plausible sublittoral ground classifications up to approximately 4 m water depth. Combining these results with seagrass mappings based on acoustic measurements (deeper than 4 m water) provides a synthesised sublittoral classification map of the study area up to the present growth limit of seagrass (~ 7 m in the study area).</p><p>The Baltic Sea is considered as a very turbid environment, nevertheless we show that satellite-based remote sensing has a great potential for shedding light into the  "white ribbon". The spatial coverage and temporal resolution of the analysed Sentinel-2 data increases the knowledge about the occurrence of seagrass and its spatio-temporal dynamics. Nevertheless, the influence of the selected atmospheric correction approach on the results shows that further research in remote sensing is necessary to assess seagrass meadows reliably.</p>

scholarly journals Exchange catalysis during anaerobic methanotrophy revealed by 12CH2D2 & 13CH3D in methane

2018 ◽  
Author(s):  
Jeanine L. Ash ◽  
Matthias Egger ◽  
Tina Treude ◽  
Issaku Kohl ◽  
Barry Cragg ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Anaerobic Oxidation Of Methane ◽  
The Baltic Sea ◽  
Methane Cycle ◽  
Isotopic Equilibrium ◽  
Sediment Samples ◽  
Oxidation Of Methane ◽  
Crucial Component ◽  
The Baltic ◽  
Methyl Coenzyme M Reductase

The anaerobic oxidation of methane (AOM) is a crucial component of the methane cycle, but its enzymatic versatility under environmental conditions remains poorly understood. We use sediment samples collected during IODP Expedition 347 to the Baltic Sea to show that relative abundances of 12CH2D2 and 13CH3D molecules in methane gas trace the reversibility of methyl-coenzyme M reductase during AOM by driving methane towards internal, thermodynamic isotopic equilibrium. These data suggest that 12CH2D2 and 13CH3D together can identify the influence of methanotrophy in environments where conventional bulk isotope ratios are ambiguous, and these findings may lead to new insights regarding the global significance of enzymatic back-flux in the methane cycle.

scholarly journals Bathymetric Properties of the Baltic Sea

2019 ◽  
Author(s):  
Martin Jakobsson ◽  
Christian Stranne ◽  
Matt O'Regan ◽  
Sarah L. Greenwood ◽  
Bo Gustafsson ◽  
...  
Keyword(s):  
High Resolution ◽  
Baltic Sea ◽  
Ocean Circulation ◽  
Deep Water ◽  
Water Exchange ◽  
The Baltic Sea ◽  
Resolution Mapping ◽  
Baltic Proper ◽  
Southern Side ◽  
The Baltic

Abstract. Marine science and engineering commonly require reliable information about seafloor depth (bathymetry), e.g. for studies of ocean circulation, bottom habitats, fishing resources, sediment transport, geohazards and site selection for platforms and cables. Baltic Sea bathymetric properties are analysed here using the using the newly released Digital Bathymetric Model (DBM) by the European Marine Observation and Data Network (EMODnet). The analyses include hypsometry, volume, descriptive depth statistics, and km-scale seafloor ruggedness, i.e. terrain heterogeneity, for the Baltic Sea as a whole as well as for 17 sub-basins defined by the Baltic Marine Environment Protection Commission (HELCOM). We compare the new EMODnet DBM with IOWTOPO, the previously most widely used DBM of the Baltic Sea which has served as the primary gridded bathymetric resource in physical and environmental studies for nearly two decades. The area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper across the Åland Sea is specifically analysed in terms of depths and locations of critical bathymetric sills. The EMODnet DBM provides a bathymetric sill depth of 88 m at the northern side of the Åland Sea and 60 m at the southern side, differing from previously identified sill depths of 100 and 70 m respectively. High-resolution multibeam bathymetry acquired from this deep water exchange path, where vigorous bottom currents interacted with the seafloor, allows us to assess what we are missing in presently available DBMs in terms of physical characterisation and our ability to then interpret seafloor processes and highlights the need for continued work towards complete high-resolution mapping of the Baltic Sea seafloor.

Collision Consequence Assessment of ROPAX Vessels Operating in the Baltic Sea

2012 ◽  
Author(s):  
Kristjan Tabri ◽  
Sören Ehlers ◽  
Mihkel Kõrgesaar ◽  
Kaarle Ståhlberg ◽  
Martin Heinvee
Keyword(s):  
Baltic Sea ◽  
Collision Risk ◽  
The Baltic Sea ◽  
Severe Injuries ◽  
Damage Scenarios ◽  
Structural Resistance ◽  
Cross Traffic ◽  
The Baltic ◽  
Initial Choice

A Ship collision accident represents a daily threat for vessels operating in dense traffic zones. The collision consequences may include loss of life or severe injuries if passengers are on board. The latter would be the case for ROPAX vessels, which are fairly dominant in the Baltic Sea connecting various member states. Furthermore, their routes tend to be in cross-traffic with the cargo vessels travelling through the full extent of the Baltic Sea. Therefore, it is of utmost importance to be able to assess the collision consequences for ROPAX vessels operating in the Baltic Sea with sufficient accuracy. This will result in an overview of possible damage scenarios for the actual traffic situation at a given location. As an example location the dense cross traffic between Helsinki and Tallinn will be analyzed and discussed. The analysis procedure combines three steps: (1) determination of possible accidental scenarios based on traffic statistics; (2) assessment of the structural resistance of the colliding ship and (3) the evaluation of selected accidental scenarios using a time-efficient semi-analytical approach. The level of structural resistance of the chosen ships is assessed in a quasi-static manner using finite element method. This information is the basis for the calibration of a semi-analytical collision simulation model used to simulate large number of the accidental scenarios typical to the selected location. The presented results will be limited to the initial choice between vessels and dimensions, respectively masses, but the procedure can easily be extended to cover a vast amount of colliding vessels. However, the actual collision risk can be obtained using the presented results if the traffic along the vessels route is known.

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