Coasts morphology

Abstract This chapter is devoted to a description of the present-day bottom topography and types of coasts of the Black Sea, as well as to the general character of the bottom sediments. Two maps of topography and sediments illustrate the morphology of the Black Sea basin and the particular features of the evolution of its coasts. 

Fig. 1 Topography of the coasts and floor of the Black Sea. Bottom relief 1 shelf a accumulative, b abrasive 2 continental slope a accumulative, b stepwise 3 floor of the basin 4 continental footstep 5 underwater canyons 6 bars a sandy, b marginal 7 morphological boundaries a distinct, b fuzzy. Coast types 1 landslide 2 abrasive 3 abrasive-accumulative 4 accumulative 5 lagoonal 6 deltaic...

The character of the coastal zone defines the morphology and type of the coasts. In mountainous areas, abrasive coasts dominate. In many cases, they are complicated owing to the development of intensive landslide and caving processes and thus may be referred to as the abrasive-denudational type. In plain and low areas, the coasts are mostly accumulative. Lagoonal and deltaic coasts are confined to the areas near river mouths. 

River mouth areas on the coasts of oceans, seas, and large lakes are very diverse in structure and hydrological regime. This diversity depends, firstly, on the morphological peculiarities of the lower reach of the river, nearshore zone of the receiving basin and coastal zone as a whole, and, secondly, on peculiarities of the hydrological regime of the river and nearshore zone of the sea. 

Diztom/Richelia intracellularis associations can be spatially extensive and contribute intensive input of N through N2 fixation in the upper water column. For instance, a Hemiaulus hauckii/Richelia bloom encountered by Carpenter et al. (1999) off the northeast coast of South America in Oct 1996 was observed over a linear cruise track of 2500 km and accounted for very substantial levels of N2 fixation (see below). The symbionts for individual diatoms such as Hemiaulus and Rhizosolenia while morphologically similar are genetically distinct and discrete probes for each association have been developed and applied in the Amazon River plume to enumerate the relative densites of these two associations (Foster et al., 2007). 

Lewis, M.S., 1968. The morphology of the fringing coral reefs along the east coast of Mahe, Seychelles. J. Geol., 76 140—153. 

Stockmann, K., Riethmiiller, R., Gayer, G, 2007, On the morphological long-term development of dumped material in a low-energetic environment close to the German Baltic coast. Journal of Mai ine Systems. In press. 

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