142 publications from this institution
No abstract is provided for this article.
There is no water body within the European Union which is surrounded by more countries than the Baltic Sea likewise no water body is more diverse regarding geological environmental and ecological conditions In response to postglacial development there is isostatic uplift in the northern part of the Baltic Sea with rates of up to 9 mm/year the southern part is sinking at rates up to 2 mm/year Crystalline rocks in the area of uplift and soft glacial and postglacial deposits in the area of sinking result in erosion and coastal retreat along the southern Baltic Sea coastline whilst the northern countries ale gaining land Additionally the marine resources of raw materials such as sand gravel and stones are of limited extent and volume in the most south westerly and southerly part of the Baltic Sea due to the late glacial and Holocene development Such conditions, combined with the predicted sea level rise will lead to an increasing demand of aggregate resources in the future due to a higher demand for shot e protection measures as soft solutions like beach and dune nourishment are favoured in many countries At the same time restrictions due to EU and national directives are increasing limiting the number of resources which can be used This introduction gives both in overview about the environmental conditions of the Baltic Sea which arc controlling the availability of sand and gravel resources and is smell a short summary about the exploitation and use of sand and gravel in the countries surrounding the Baltic Sea
Electrical prospecting of soils and rocks is far more diversified than other geophysical methods. Some techniques use natural electrochemically-generated currents, the so called self-potential method. Other techniques make use of electric currents or fields that are introduced into the ground. The resistivity method has been traditionally used for differentiating oil and gas bearing from water saturated rocks. The main scope of this paper is to investigate the applicability of using electrical methods to evaluate some geological and geotechnical parameters of marine sediments concerning engineering and environmental problems.
Schwarzer, K.; Nguyen Cong Thanh and Ricklefs, K., 2016. Sediment re-deposition in the mangrove environment of Can Gio, Saigon River estuary (Vietnam). In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 138–142. Coconut Creek (Florida), ISSN 0749-0208.Sediment re-deposition in mangrove environments is usually attributed to marine and estuarine hydrodynamics - rainfall as a driver was not considered yet. However, combined with annual water level variations, tropical rainfall can play a significant role for sediment re-deposition. Inside mangroves, current velocities induced by rainwater runoff during low tide conditions can be much stronger than tide-induced currents. Along the Saigon River Estuary and the Mekong Delta coastline, rainfall is high from May to October and low from December to April. To study processes controlling sediment re-deposition, data of current and suspended matter concentration have been combined with sediment re-deposition rates. All investigations have been carried out in the Can Gio mangrove reserve, Saigon River mouth. Based on a 19-year data set (1991 – 2009), strong annual variability in water level heights and tidal range are observed, with a mean maximum high tide level of 3.34 m during the rainy season and 3.73 m at the beginning of the dry season. Maximum tidal range is reached during the rainy season coinciding with the lowest annual average sea level. The highest parts of the mangrove forest are not inundated by tides during these periods. Only heavy rainfall during these times can lead to mangrove soil mobilisation, induce strong currents between the mangrove roots and cause erosional gullies. Depending on the amount of precipitation, this sediment mobilisation and the amount of suspension load in the forest can be much stronger than sediment transport induced by tidal currents.
Die geologisch / sedimentologische Ausbildung des Meeresbodens bestimmt neben der Exposition eines Kustenabschnittes und der Nahrstoffzufuhr masgeblich die Abundanz von Zoo- und Phytobenthos. Die Zielsetzung dieses Projektes war es, die sedimentologische Beschaffenheit des Meeresbodens seewarts des Brodtener Ufers mittels hydroakustischer Messsysteme in einem ausgewahlten Areal flachendeckend zu erfassen und die Ergebnisse in einer Karte darzustellen. Weiterhin sollte eine Zusammenstellung von bereits im Institut fur Geowissenschaften der Christian-Albrechts-Universitat zu Kiel (IfG) vorhandener Seitensichtsonar-Daten aus der Lubecker Bucht erfolgen.
Can Gio (CG), a mangrove forest with a dense network of tidal creeks, gradually grew and spread seaward on a coastal platform, which was built since about 8 ka before present (BP). Along with this development, a sand ridge began to form and moved back with the shoreline withdrawal landward in the Late Holocene. This mangrove environment is likely abandoned from the mainland but was, however, the place for settlement of ancient Vietnamese a few centuries BC. The CG mangrove forest was severely destroyed during the American War and was restored since 1980. However, the historical change of the landscape along the Saigon-Dong Nai River (SG-DNR) since the Late Holocene is not completely unraveled. By analyzing sediment cores with a multiproxy approach, we investigated the recent geological development with regard to the variation of the intensity of the East Asian palaeomonsoon and regarding the accommodation space, as both regulate the development of this coastal environment. A recently significant shift in the coastline, mainly due to a change of hydroclimatic factors, was observed. A continuous coastline retreat occurred over the last millennium, changing the depositional environment and reshaping the CG mangrove landscape. Along the present coast and tidal channels, partially strong erosion and bank failures occur, alternating with accretion at other coastal sections. This development tends to increase progressively.
The coastal development of the Rio Aqu area (Rio Grande do Norte, Brazil) and the response of the river mouth to the Holocene sea level rise were reconstructed from seismostratigraphy. A sharply defined stratigraphic boundary between the Pleistocene and Holocene deposits was recognised. The seismic data reveal that, during sea level lowstand, a valley up to 9 km wide was cut into the Pleistocene deposits of the shelf platform. This valley extends perpendicular to the shoreline and is preserved in the recent morphology. It narrows at similar to 20 kin offshore to a I km wide channel, which then widens to its former size a few hundred meters further offshore. Several incised valleys and cut and fill structures up to 2500 in wide and 12 in deep were observed in the Pleistocene deposits. These extend to 45 in below sea level, and indicate that the ancient Rio Aqu meandered. A sediment sequence with sigmoidal structures increases in thickness offshore to 12 in, is composed of reworked material, and is interpreted as an embankment. A tilted block composed of more solid material was identified over a distance of at least 800 in. Holocene sediments thin out above this block, indicating postglacial neotectonics in the area.
