in: OIL SPILL ALONG THE TURKISH STRAITS SEA AREA; ACCIDENTS, ENVIRONMENTAL POLLUTION, SOCIO-ECONOMIC IMPACTS AND PROTECTION, SELMA ÜNLÜ,BEDRİ ALPAR,BAYRAM ÖZTÜRK, Editor, TÜDAV, İstanbul, pp.61-78, 2018
GEOGRAPHY,BATHYMETRY AND HYDRO-METEOROLOGICAL CONDITIONS
This chapter provides an outline of the background information regarding the geographic, bathymetric restrictions and hydrodynamic conditions along the Turkish Straits Sea Area. Wind and wave climate of the region has been reviewed. The Turkish Straits are not so shallow for navigation but their shape and seabed morphology are physical constraints defining the water exchange between the adjacent marine realms. Strong surface currents and eddies along the straits, limited maneuvering space due to sharp turns, and unpredictable weather conditions make it difficult to navigate through the Turkish Straits safely. Therefore, all kind of geologic, hydrographic, oceanographic, and meteorological data will be crucial for environmental researches and used for maritime transportation. Sea bottom topography along the İstanbul Strait, for example, reveals physical constraints that sailors have to pay attention during their navigation. Oil cannot dissolve in water, so its fate depends on the dominant oceanographic and hydrodynamical conditions. Wind driven waves and currents move oil onto shore. Oil waste interacts with sediments, depending on its texture, and causes contamination along the coast. Research on the oceanographic conditions and water dynamics along the Turkish Straits Sea Area started with the early developments in the late 19th and early 20th centuries. Modern oceanographic measurement and systematic research programs, which could be merely established in the 1970’s, have revealed general and widely different characteristics of the circulation system along the Turkish Straits Sea Area and the neighboring basins. Therefore, the circulation of the Sea of Marmara is coupled to the flow dynamics at both of the straits. The roles of two sills and a contraction in the İstanbul Strait, as well as the single contraction in the Çanakkale Strait, are understood in the establishment of two different water exchange regimes along these straits. As the current and wave conditions must be known in advance for safe navigation, hydrodynamic and wave climate characteristics of the region have been outlined. Numerical modeling of the currents along the Turkish Straits, which are rare natural phenomena of two-layer flow with opposing currents, is a necessary tool especially for predicting the paths of the oil spills.