Secular sea level variations along the Turkish coasts

Bedri Alpar, Hüseyin Yüce, Ertuğrul Dogan

Istanbul University, Department of Marine Sciences and Management, 34470 Vefa, Istanbul, TURKEY
Department of Navigation, Hydrography and Oceanography, 81647, Çubuklu, Istanbul, TURKEY

Abstract

The characteristics of secular sea level variations along the Turkish coasts have been investigated based upon a sequence of hourly sea level observations at Samsun, Karşıyaka (lzmir) and Antalya. Significant monthly oscillations were calculated from the power spectral estimates: which occur at 12, 6, 4 months periods at Samsun: 21.3, 12, 6, 5, 4.1 months at Karşıyaka and 12, 6, 4 months periods at Antalya. For secular changes, the decreasing trend at Samsun tide station, -6.9 mm per year, is contrary to the secular rising trend of the Black Sea probably because of its rather short monitoring period (1963-77). A rise of 3.2 mm per year in annual sea level is computed for Karşıyaka (1935-71). A linear decreasing trend ( -0.4 mm per year between 1935-77) has been observed for annual sea levels at Antalya.

Keywords: Secular sea level variations, global sea-level changes, power spectra

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