Publications

Kartierung von Steinfeldern – Probleme und Lösungsansätze

No abstract is provided for this article.

Herstellung und Umwandlung von Estern der unterhalogenigen Säuren

Thieme E-Books & E-Journals

Sea floor deposits in Keibu Bay and Nõva Bay (northwestern Estonia) and the adjacent offshore area

Grain-size distribution of sea floor deposits of Nõva Bay and Keibu Bay, northwestern Estonia, is discussed.Based on grain-size statistics, the lateral and vertical distribution of different types of bottom sediments is shown and compared for the two bays.The bottom deposits consist mostly of sand (80-100%).The proportion of silt and gravel is considerably smaller: up to 3% in Nõva Bay and up to 7% in Keibu Bay.In Nõva Bay medium sand predominates.Grain-size distribution of deposits is rather uniform and an obvious correlation exists between the occurrence of different fractions and the water depth.In Keibu Bay sand of different grain size prevails.Along the boundary between the mouths of the bays and the open sea, a belt of coarse sand runs parallel with the shoreline.Beyond this belt silt and clay are predominant.

Decadal scale stability of sorted bedforms, German Bight, southeastern North Sea

Impact of 2004 Tsunami on Seafloor Morphology and Offshore Sediments, Pakarang Cape, Thailand

This study documents seafloor morphology and sediments based on multibeam, side-scan sonar and boomer surveys, as well as sediment samples taken on the inner to mid shelf of the Andaman Sea after the 2004 Indian Ocean tsunami. Preservation of submarine relief in former underwater mining areas points to limited impact of the tsunami, while channel structures parallel to the observed tsunami backwash indicate a possible higher impact. Therefore, the tsunami impact seems to be focused on some areas. The impact was probably most effective during the backwash, when stiff mud deposits containing grass, wood fragments and shells were transported by high density backwash flows. Moreover, several boulders, which might have been deposited during the tsunami backwash flow, were found in the channels in front of Pakarang Cape.

Erosion Between Two Delta Fronts, the Mekong Delta Case

No abstract is provided for this article.

Mapping the plastic legacy: Geospatial predictions of a microplastic inventory in a complex estuarine system using machine learning

Sediments store the majority of the microplastic legacy in the aquatic environment. To predict microplastic distribution in sediments, models have been developed focussing on coarse ocean basin scales or suited to relatively simple geomorphological and hydrodynamic systems. However, such models reach their limits in more complex estuarine systems, leaving a significant lack of modelling capability for microplastic pollution in key ecosystems. We address this gap by employing machine learning techniques to predict spatial MP inventories deposited in the Schlei, Northern Germany. Notably, the complex hydrodynamic regime, influenced by narrowings and braided embayments, freshwater tributaries, wind-driven mixing, and brackish inflows, creates an interplay of fluvial and marine sedimentary processes, which poses non-trivial challenges for reliable modelling of sedimentary MP transportation. Our approach, termed NIXVEGS (Nested Iterative X-Validation-to-Ensemble-modelling through GridSearches), leverages machine learning, integrating model selection, rigorous validation, and ensemble techniques tailored for small datasets. We estimated 20 trillion MP particles or 14.5 tonnes (50-5000 µm) residing in upper sediments of the Schlei proper, representing the highest resolution picture of an MP inventory for an entire geomorphological region to date. Our modelling concept is founded on the idea of applying granulometric proxies to account for the hydrodynamic regime bias in observed MP concentrations. Estuarine sediments store some of the highest MP concentrations among all sediment types. As depositional systems at the terrestrial-aquatic and fluvial-marine interface, they are key indicator ecosystems for monitoring the evolution of (micro)plastic pollution. Optimising sampling strategies for sediment grain size coverage and spatio-temporal hydrodynamics, and using models such as NIXVEGS, will be important to understand the contribution of complex estuarine systems to the global microplastic budget. Also see: https://micro2024.sciencesconf.org/559755/document

A. Herstellung von Lactonen : I. Intramolekulare Cyclisierungen (I)

Thieme E-Books & E-Journals

Identificação de superfícies de reativação em dunas, como guia para aquisição de dados de GPR 3D com alta densidade

PreviousNext No Access12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011Identificação de superfícies de reativação em dunas, como guia para aquisição de dados de GPR 3D com alta densidadeAuthors: Antônio Lisboa Fernandes JúniorJosibel Gomes de Oliveira JúniorWalter Eugênio de MedeirosHelenice VitalKarl StatteggerKlaus SchwarzerAntônio Lisboa Fernandes JúniorDepartamento de Geologia (UFRN);, Josibel Gomes de Oliveira JúniorDepartamento de Geologia (UFRN);, Walter Eugênio de MedeirosDepartamento de Geologia (UFRN);, Helenice VitalDepartamento de Geologia (UFRN);, Karl StatteggerChristian-Albrechts Universitaet zu Kiel, and Klaus SchwarzerChristian-Albrechts Universitaet zu Kielhttps://doi.org/10.1190/sbgf2011-092 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract This paper is in Portuguese. To understand the depositional process of a sand dune located on Sylt Island, northern region of Germany, a Ground Penetrating Radar (GPR) survey was carried out. The survey is composed by eighty profiles in SE-NW and NE-SW directions. The data allowed the identification of different generations of dunes and bounding surfaces, especially reactivation surfaces associated to changes in wind patterns and can be used as markers to conduct future dense 3D GPR survey. Keywords: GPR, 3DPermalink: https://doi.org/10.1190/sbgf2011-092FiguresReferencesRelatedDetails 12th International Congress of the Brazilian Geophysical Society & EXPOGEF, Rio de Janeiro, Brazil, 15–18 August 2011ISSN (online):2159-6832Copyright: 2011 Pages: 2223 publication data© 2011 Published in electronic format with permission by the Brazilian Geophysical SocietyPublisher:Society of Exploration Geophysicists HistoryPublished Online: 13 Mar 2014 CITATION INFORMATION Antônio Lisboa Fernandes Júnior, Josibel Gomes de Oliveira Júnior, Walter Eugênio de Medeiros, Helenice Vital, Karl Stattegger, and Klaus Schwarzer, (2011), "Identificação de superfícies de reativação em dunas, como guia para aquisição de dados de GPR 3D com alta densidade," SEG Global Meeting Abstracts : 436-440. https://doi.org/10.1190/sbgf2011-092 Plain-Language Summary KeywordsGPR3DPDF DownloadLoading ...

A. Herstellung von Lactonen : II. Spontane Lactonisierung bei der Synthese cyclisationsfähiger Verbindungen (I)

Thieme E-Books & E-Journals

B. Umwandlung von ß-Lactonen : V. Sonstige Ringspaltungsreaktionen

Thieme E-Books & E-Journals

Identification of submarine hard-bottom substrates in the German North Sea and Baltic Sea EEZ with high-resolution acoustic seafloor imaging

Submarine hard bottoms (e.g., boulders, outcropping strata) are of particular ecological importance. They were investigated in the Exclusive Economic Zones (EEZ) of the German North Sea and the Baltic Sea, using high-resolution seafloor imaging techniques (i.e.,...

Evolution of the Parnaíba Delta (NE Brazil) during the late Holocene

Sedimentary processes and the evolution of the wave- and tide-dominated, asymmetric Parnaíba Delta during the late Holocene were investigated based on

A. Herstellung von Sauerstoff- und Thiosäureestern des Arsens und Antimons : III. Thiosäureester des Arsens und Antimons

Thieme E-Books & E-Journals

Geological setting of areas endangered by waves generated by fast ferries in Tallinn Bay

The paper considers the distribution of bottom deposits in Tallinn Bay in connection with the general geological setting.The shores subject to intense ship wash (western coast of the Viimsi Peninsula, SW coast of Aegna Island, and eastern coast of Naissaar Island) are discussed in greater detail.Distribution of bottom deposits is determined by the location of erosion areas and seafloor topography.The shores of the bay are mostly covered with coarse material washed out from glacial deposits, which reduces the influence of the waves.During the periods with low water level the waves generated by fast ferries influence deeper parts of the nearshore.

Wadden Sea Quality Status Report 2017,Common Wadden Sea Secretariat, Wilhelmshaven, Germany

No abstract is provided for this article.

Circular structures on the seabed: differentiating between natural and anthropogenic origins—Examples from the Southwestern Baltic Sea

Hydroacoustic observations of shallow marine environments reveal a variety of seafloor structures–both of natural and anthropogenic origin. Natural processes can result in features with circular geometries on the seafloor, such as kettles, sinkholes or iceberg pits, but human activities such as dredging, dumping, or detonating explosives can also cause similar shapes. Explaining the origin of these features is difficult if there are only few observations or if competing natural and anthropogenic processes have acted in the same area. Even though the location of dredging and dumping operations and munition blasting may be well documented in many parts of the global coastal ocean today, little information might be available about human practices in the past. In this study, more than 3,000 circular features were identified in side-scan sonar (SSS) datasets covering 1,549 km 2 of shallow waters in the southwestern Baltic Sea. Additional data obtained by multibeam echosounder (MBES), sub-bottom profiler (SBP), and different SSS was considered in the analysis of 205 circular features that were characterized based on their sedimentology, morphology, SSS and SBP acoustic signatures. Characteristic differences between the structures allow their classification into six classes, which provide insight into their formation mechanisms. The obtained parameters (morphology, MBES and SSS acoustic backscatter, SBP characteristics and spatial distribution) allow the classification to be applied to the entire SSS dataset, resulting in the classification of 2,903 features. The mapped circular features have diameters between 6 and 77 m and correspond to pockmarks, dumping spots and explosion craters in water depths ranging from 8 m up to 25 m. Despite this rather multi-methodological approach, the origin of some observed features still cannot be explained with certainty, leaving room for further investigations of natural processes and human impacts on the seafloor.

Die Wasserstände an der Ostseeküste - Entwicklungen - Sturmfluten - Klimawandel 1. Wasserstandsentwicklung in der südlichen Ostsee während des Holozäns

No abstract is provided for this article.

Germany

'Germany' published in 'Encyclopedia of the World's Coastal Landforms'