October 21, 2011

Colloquium Speaker: Isaac Gertman


Isaac Gertman is head of the Physical Oceanography Department in Israel Oceanographic & Limnological Research (Haifa) since 2005. He holds a Masters Degree in Oceanology from the Russian State Hydrometeorological University, St. Petersburg (1972), and a Ph.D. in Physical Oceanography from the State Institute of Oceanography in Moscow, (1986). His scientific activities started in the Murmansk Department of Arctic and Antarctic Research, Russia (1973-1978). Dr. Gertman began investigating interannual variability of the physical structure and circulation in the Black Sea and Mediterranean Sea, while in Sevastopol at the State Oceanographic Institute (1979-1991). He repatriated in Israel in 1991 and since 1994, he has been a scientist at the Israel Oceanographic and Limnological Research. He is also a Lecturer at the Israel Maritime College. His current main interests, with regional specialization in the Dead Sea and Mediterranean, are: (i) long-term changes in marine thermo-haline structures and circulation; (ii) marine operational forecasting; and (iii) oceanographic data bases development. He is an author or co–author of numerous refereed journal articles, contributions to books, and conference proceedings. This year he has been spending a sabbatical at the Ocean Climate Laboratory, National Oceanic and Atmospheric Administration (NOAA).




Colloquium Topic: Amazing Interannual Variability of the Dead Sea Hydrological Regime

For hundreds of years prior to 1950, the Dead Sea surface level was about 400 ± 20 m below sea level. During this period dilution of the upper layer by the fresh water runoff was sufficient to support stable stratification due to low salinity in the upper layer (about 247 g/kg) and high salinity in the deep layer (about 276 g/kg) even during the winter seasons. Since then, anthropogenic reduction of runoff and water consumption for industrial mineral production have led to significant changes in the dimensions and hydrology of the Dead Sea. The sea level has been dropping almost continuously since 1960, when it was 397 m below sea level. During the last 16 years the rate of the level decrease has been about 1 m/year and by Spring 2011 the Dead Sea level was 424 m below sea level. Gradual salinity increase in the upper layer led to the first overturn of the two layer structure in winter 1978-1979 bringing to an end the long-term stable hydrological regime. A haline stratification, preventing winter overturns, was restored twice after the extremely rainy winters of 1980 and 1992. Halite in the Dead Sea has been saturated since about 1980 and permanent precipitation has been observed on submerged objects. In 2005 the governments of Israel, Jordan and the Palestinian Territories, supported by the World Bank, agreed to conduct a feasibility study for a canal or pipeline, between the Gulf of Aqaba and the Dead Sea, transporting initially Red Sea water and eventually high salinity end brines (byproduct of desalinization) into the Dead Sea.