The Anatolian side of Turkey is the largest portion in the countrySarıkaya, M. A. The Late Quaternary glaciation in the Eastern Mediterranean. In: Hughes P, Woodward J (eds) Quaternary glaciation in the Mediterranean mountains. Geological Society of London Special Publication 433, 2017, pp. 289–305. that bridges southeastern Europe and west Asia. East Thrace, the European portion of Turkey comprises 3%The Dorling Kindersley World Reference Atlas. New York: Dorling Kindersley, 2014. of the landmass but over 15% of the population. East Thrace is separated from Asia Minor, the Asian portion of Turkey, by the Bosporus, the Sea of Marmara and the Dardanelles.Erturaç, M. K. Kinematics and basin formation along the Ezinepazar-Sungurlu fault zone, NE Anatolia, Turkey. Turk J Earth Sci 21: 2012, pp. 497–520. İskilip, Çorum province, is considered to be the geographical center of Earth. Turkey is very vulnerable to earthquakes.
External boundaries
Turkey’s frontiers with Greece—206 kilometers—and Bulgaria—240 kilometers— were settledFinkel, Andrew, and Nükhet Sirman, eds. Turkish State, Turkish Society. New York: Routledge, 1990. by the Treaty of Constantinople (1913) and later confirmed by the Treaty of Lausanne in 1923. The 1921 treaties of MoscowGeoffrey Lewis, Modern Turkey. New York: Praeger, 1974. and Kars with the Soviet Union defines Turkey’s current borders with Armenia (268 kilometers), Azerbaijan (9 kilometers), and Georgia (252 kilometers). The 499-kilometer Iranian border was first settled by the 1639 Treaty of Kasr-ı Şirin and confirmed in 1937.Shaw, Stanford J., and Ezel Kural Shaw. History of the Ottoman Empire and Modern Turkey. (2 vols.) Cambridge University Press, 1976. With the exception of Mosul, Turkey ceded the territories of the present-day Iraq and Syria with the Treaty of Lausanne in 1923. In 1926, Turkey ceded Mosul to the United Kingdom in exchange for 10% of the oil revenues from Mosul for 25 years. Syria’s border with Turkey changed with the 1939 transfer of Hatay Province, following a referendum that favored union with Turkey.
Regions
The First Geography Congress, held in Ankara between 6–21 June 1941, divided Turkey into seven regions after long discussions and work. These geographical regions were separated according to their climate, location, flora and fauna, human habitat, agricultural diversities, transportation, topography, etc. At the end, 4 coastal regions and 3 inner regions were named according to their proximity to the four seas surrounding Turkey, and their positions in Anatolia.
Turkey has a diverse terrain: the plains of Anatolia, and forests of the Black Sea, semi-arid lands, natural lakes and the coastlines of the Aegean and Mediterranean. The Anatolian plain is separated from the Black Sea by the Pontic Mountains, converging with the Taurus Mountains in the Northeast of the country where Mount Ararat is located. The full territory of Turkey is 783,356 square kilometers (756,688 of those in Anatolia, and 23,764 in European Thrace).Heper, Metin, Duygu Öztürk-Tunçel, and Bilge Criss. 2018. Historical dictionary of Turkey.
Black Sea region
The physical geography of the Black Sea region landscapes is characterized by the mountain range forming a barrier parallel with the Black Sea Coast and high humidityDelaney, Carol. The Seed and the Soil of Turkey. Berkeley: University of California Press, 2011. and precipitation.Akçar, N. Paleoglaciations in Anatolia: A schematic review and first results. Eiszeitalt Gesellschaft für Geowissenschaften 55: 2005, pp. 102–121. The eastern Black Sea region presents alpine landscapesErinç, S. Glacial evidences of the climatic variations in Turkey. Annals of the American Association of Geographers 34: 1952, pp. 89–98. with steep and densely forested slopes. Steep slopes, as a morphological feature, occur both under the sea, and in the mountain ranges, with the sea floor at below 2000 m along a line from Trabzon to the Turkish–Georgian border, and the mountains quickly reaching over 3000 m, with a maximum of 3971 mBirman, J. H. Glacial reconnaissance in Turkey. Geological Society of America Bulletin 79: 1968, pp. 1009–1026. in Kaçkar Peak. The parallel valleys running north to the Black Sea used to be isolated from one another until a few decades ago because the densely forested ridges made transportation and exchange very difficult.Fleischer, R. The rock-tombs of the Pontic Kings in Amaseia (Amasya). In: Højte JM (ed) Mithridates VI and the Pontic Kingdom, Black Sea Studies, vol 9. Aarhus University Press, Aarhus, 2009, pp. 109–120. This allowed for the development of a strong cultural identity— the Laz language, music and dance—linked to this specific geographic context.
From west to east, the main rivers of the region are the Sakarya (824 km), the Kızılırmak River (1355 km, the longest river of Turkey), the Yeşilırmak (418 km) and the Çoruh (376 km).
Year-round high precipitation—up to 2200mmTunçel, H. Doğu Karadeniz Dağlarında Yaylacılık. Fırat Üniversitesi Sos Bilim Derg (Elazığ) 14(2): 2004, pp. 49–66.—generate dense forests, with oak, beech family trees, hazel (Corylus avellana), hornbeam (Carpinus betulus) and sweet chesnut (Castanea sativa) prevailing.Kurdoğlu, O. Doğal ve Kültürel Değerlerin Korunması Açısından Kaçkar Dağları Milli Parkı’nın Önemi ve Mevcut Çevresel Tehditler. D.K. Ormancılık Araştırma Müdürlüğü, Ormancılık Araştırma Dergisi 21, ve Çevre ve Orman Bakanlığı Yayını 231: 2004, pp. 134–150.
Isolated from one another because of steep valleys, the Black Sea region includes 850Ekim, T. Türkiye Bitkileri Kırmızı Kitabı. 2000. plant taxa of which 116 is endemic to the area, and of which 12 are endangered and 19Brickell, Christopher. Encyclopedia of Plants and Flowers. New York: Dorling Kindersley, 2011. vulnerable. Hazelnut is a native species for this region, which covers 70 and 82% of the world's production and exports respectively.
The Kaçkar Range at altitudes of 3000 m and above is heavily glaciated owing to the suitable geomorphological- climatological conditions during the Pleistocene.
Marmara region
The European portion of Turkey consists mainly of rolling plateau country well suited to agriculture.
Densely populated, this area includes the cities of Istanbul and Edirne. The Bosphorus, which links the Sea of Marmara and the Black Sea, is about twenty-five kilometers long and averages 1.5 kilometers in width but narrows in places to less than 1,000 meters. There are three suspension bridges over the Bosphorus, both its Asian and European banks rise steeply from the water and form a succession of cliffs, coves, and nearly landlocked bays. Most of the shores are densely wooded and are marked by numerous small towns and villages. The Dardanelles (ancient Hellespont) strait, which links the Sea of Marmara (ancient Propontis) and the Aegean Sea, is approximately forty kilometers long and increases in width toward the south. Unlike the Bosphorus, the Dardanelles has fewer settlements along its shores. The Saros Bay is located near the Gallipoli peninsula and is disliked because of dirty beaches. It is a favourite spot among scuba divers for the richness of its underwater fauna and is becoming increasingly popular due to its vicinity to Istanbul.
The most important valleys are the Kocaeli Valley, the Bursa Ovası (Bursa Basin), and the Plains of Troy (historically known as the Troad). The valley lowlands around Bursa is densely populated.
Aegean region
Located on the western side of Anatolia, the Aegean region has fertile soil and a typically Mediterranean climate; with mild, wet winters and hot, dry summers. The broad, cultivated valley lowlands contain about half of the country's richest farmlands.
The largest city in the Aegean region of Turkey is İzmir, which is also the country's third-largest city and a major manufacturing center; as well as its second-largest port after Istanbul.
Olive and olive oil production is particularly important for the economy of the region. The seaside town of Ayvalık and numerous towns in the provinces of Balıkesir, İzmir and Aydın are particularly famous for their olive oil and related products; such as soap and cosmetics.
The region also has many important centers of tourism which are known both for their historic monuments and for the beauty of their beaches; such as Assos, Ayvalık, Bergama, Foça, İzmir, Çeşme, Sardis, Ephesus, Kuşadası, Didim, Miletus, Bodrum, Marmaris, Datça and Fethiye.
Mediterranean region
Toward the east, the extensive Cilician Plain, around Adana, Turkey's fifth most populous city, consist largely of reclaimed flood lands. In general, rivers have not cut valleys to the sea in the western part of the region. Historically, movement inland from the western Mediterranean coast was difficult. East of Adana, much of the coastal plain has limestone features such as collapsed caverns and sinkholes. Between Adana and Antalya, the Taurus Mountains rise sharply from the coast to high elevations. Other than Adana, Antalya, and Mersin, the Mediterranean coast has few major cities, although it has numerous farming villages.
Paralleling the Mediterranean coast, the Taurus Mountains () are Turkey's second chain of folded mountains. The range rises just inland from the coast and trends generally in an easterly direction until it reaches the Arabian Platform, where it arcs around the northern side of the platform. The Taurus Mountains are more rugged and less dissected by rivers than the Pontic Mountains and historically have served as a barrier to human movement inland from the Mediterranean coast except where there are mountain passes such as the historic Cilician Gates (Gülek Pass), northwest of Adana.
Central Anatolia region
Stretching inland from the Aegean coastal plain, the Central Anatolia region occupies the area between the two zones of the folded mountains, extending east to the point where the two ranges converge. The plateau-like, semi-arid highlands of Anatolia are considered the heartland of the country. The region varies in elevation from 700 to 2000 meters from west to east. Mount Erciyes is the peak at 3916 meters. The two largest basins on the plateau are the Konya Ovası and the basin occupied by the large salt lake, Tuz Gölü. Both basins are characterized by inland drainage. Wooded areas are confined to the northwest and northeast of the plateau. Rain-fed cultivation is widespread, with wheat being the principal crop. Irrigated agriculture is restricted to the areas surrounding rivers and wherever sufficient underground water is available. Important irrigated crops include barley, corn, cotton, various fruits, grapes, opium poppies, sugar beets, roses, and tobacco. There also is extensive grazing throughout the plateau.
Central Anatolia receives little annual rainfall. For instance, the semi-arid center of the plateau receives an average yearly precipitation of only 300 millimeters. However, actual rainfall from year to year is irregular and occasionally may be less than 200 millimeters, leading to severe reductions in crop yields for both rain-fed and irrigated agriculture. In years of low rainfall, stock losses also can be high. Overgrazing has contributed to soil erosion on the plateau. During the summers, frequent dust storms blow a fine yellow powder across the plateau. Locusts occasionally ravage the eastern area in April and May. In general, the plateau experiences moderate heat, with almost no rainfall in summer and cold weather with heavy snow in winter.