Teaching of the subject “density difference caused by salinity", one of the reasons that plays role in the occurrence of currents in straits, seas and oceans by the use of a teaching material Verim Gümüşsoy 1, 2 1 Poster B29, Abstract EGU2015-2437 Geography Teacher, Harmandere Vocational and Technical Anatolian High School, Pendik, Istanbul, Turkey ([email protected]) 2 Postgraduate Student, Department of Geography, Sakarya University, Serdivan, Sakarya, Turkey ([email protected])

CURRENTS IN STRAITS, SEAS AND OCEANS SUBSURFACE CURRENTS IN THE BOSPORUS CURRENT DEMONSTRATION • I get my students to carry out a small demonstration to help • Large masses of moving water in seas The Black Sea Black Sea them understand the occurrence of ocean currents and and oceans are called currents. currents in the seas and the Bosporus by the use of a material. • Fundamental reasons of currents are The

Bosporus Marmara Sea steady winds that occur due to the Istanbul • We need very simple materials to carry out this Aegean global atmospheric system and the Marmara Sea Sea demonstration: An aquarium, a bowl, water, salt, dye and any density differences caused by different stick to mix. heat and salinity levels of water masses. • As Marmara Sea has higher salt amount than Black Sea, • Different feeding and there is a great density difference between these two seas. evaporation • Marmara Sea has a higher concentration of salt and characteristics of seas therefore a higher density than Black Sea. and oceans result in • The demonstration is carried out as follows: we put water, salt salinity and density • And this leads to occurrence of subsurface currents in the and dye in the bowl and mix it well. levels. Bosporus (Istanbul Strait) from Marmara to Black Sea. • The salt will increase the density of the water and the dye will • As a result, subsurface help distinguish the salty water. currents occur in straits Current Velocity Salinity of • Then we put tap water half way to the aquarium and pour the from Bosporus Bosporus mixture in the bowl to the aquarium slowly. where seas with to Black Sea Current different salinity and density levels meet and in the nearby seas. IMPORTANCE OF TEACHING MATERIAL IN GEOGRAPHY LESSONS SALINITY LEVEL DIFFERENCE OF BLACK SEA • Natural events occur in very long periods by great dynamic systems, making understanding of them difficult. • The Bosporus in Istanbul • It is important to use different kinds of materials that address where I live and the school I to different senses in geography lessons to promote effective am working at is has these and fun learning. subsurface currents. CONCLUSIONS • As a result, the colored salty water sinks down due to its higher • In the Black Sea where the rivers the Danube, Dnieper, density, setting an example of a subsurface current. Dniester, Don, Coruh and Kizilirmak flow into and the • The use of this material will help students comprehend how evaporation level is less due to the latitude effect, salinity level subsurface currents in the straits, seas and oceans occur. is less compared to Marmara and Aegean Seas. • By this simple experiment, students will be able to see what Several examples of teaching materials to use in the geography lesson. kind of a movement takes place under the Bosporus on which • Thus, geography lessons should be based on teaching they travel by ferry and they will have the opportunity to carry principles such as ‘from concrete to abstract’ and ‘from it out themselves, making the lesson more fun. near-to-far’ principles. REFERENCES Doğanay, H. (2002). Coğrafya Öğretim Yöntemleri. Aktif Yayınevi, Erzurum https://www.windows2universe.org/earth/Water/images/ocean_currents.jpg İzbırak, R. (1989). Sular Coğrafyası. Milli Eğitim Gençlik ve Spor Bakanlığı Yayınları, Öğrt.Kit. Diz:59, İstanbul http://upload.wikimedia.org/wikipedia/commons/4/4c/Thermohaline_Circulation_2.png • Also, teaching methods such as visualization, simulation Kehse, U. (2006). Die Klima Maschine. Geokompakt Nr.9 , s.70-80 http://www.angelfire.com/fl/BriansHouse/briansstudy/blackseacurrent.gif An important feature of the Black Sea is Özsoy, E. v.d. (2000). Türk Boğazlar Sistemi’nin Oşinografisi. Marmara Denizi 2000 Sempozyumu,11-12. http://blacksea-education.ru/e2.shtml an unusually high river discharge into the and experiment should be applied during the lessons. Türkeş, M. (2010). Klimatoloji ve Meteoroloji. Kriter Yayınevi, Yayın No:63, İstanbul http://www.ims.metu.edu.tr/Sayfa.php?icerik=DuyuruOku&did=721 relatively small semi-enclosed Sea. This demonstration is accessible on YouTube with the title “Teaching Material About Subsurface Currents”. ( https://www.youtube.com/watch?v=1b8YbJCOCrg )