The Ottoman Empire at its greatest extent.Encyclopædia Britannica, Inc.
Land
Relief
Encyclopædia Britannica, Inc.
Ararat, MountMount Ararat, viewed from Turkey.© Vladislav Jirousek/Dreamstime.comTurkey is a predominantly mountainous country, and true lowland is confined to the coastal fringes. About one-fourth of the surface has an elevation above 4,000 feet (1,200 metres), and less than two-fifths lies below 1,500 feet (460 metres). Mountain crests exceed 7,500 feet (2,300 metres) in many places, particularly in the east, where Turkey’s highest mountain, Mount Ararat (Ağrı), reaches 16,945 feet (5,165 metres) close to the borders with Armenia and Iran. In the southeast the Uludoruk Peak reaches 15,563 feet (4,744 metres); though further west, the Demirkazık Peak (12,320 feet [3,755 metres]) and Mount Aydos (11,414 feet [3,479 metres]) are also significant peaks. Steep slopes are common throughout the country, and flat or gently sloping land makes up barely one-sixth of the total area. These relief features affect other aspects of the physical environment, producing climates often much harsher than might be expected for a country of Turkey’s latitude and reducing the availability and productivity of agricultural land. Structurally, the country lies within the geologically young folded-mountain zone of Eurasia, which in Turkey trends predominantly east to west. The geology of Turkey is complex, with sedimentary rocks ranging from Paleozoic to Quaternary, numerous intrusions, and extensive areas of volcanic material. Four main regions can be identified: the northern folded zone, the southern folded zone, the central massif, and the Arabian platform.
The northern folded zone
The northern folded zone comprises a series of mountain ridges, increasing in elevation toward the east, that occupy a belt about 90 to 125 miles (145 to 200 km) wide immediately south of the Black Sea. The system as a whole is referred to as the Pontic Mountains (Doğukaradeniz Dağları). In the west the system has been fractured by the faulting that produced the Turkish straits; in Thrace the Ergene lowlands are among the largest in the country, and the main mountain range—the Yıldız (Istranca)—reaches only 3,379 feet (1,030 metres). Lowlands also occur to the south of the Sea of Marmara and along the lower Sakarya River east of the Bosporus. High ridges trending east-west rise abruptly from the Black Sea coast, and the coastal plain is thus narrow, opening out only in the deltas of the Kızıl and Yeşil rivers. These rivers break through the mountain barrier in a zone of weakness where summits are below 2,000 feet (600 metres), dividing the Pontic Mountains into western and eastern sections. In the western section, between the Sakarya and Kızıl rivers, there are four main ridges: the Küre, Bolu, Ilgaz, and Köroğlu mountains. East of the Yeşil the system is higher, narrower, and steeper. Less than 50 miles from the coast, peaks rise to more than 10,000 feet (3,000 metres), with a maximum elevation of 12,917 feet (3,937 metres) in the Kaçkar range. Separated by the narrow trough of the Kelkit and Çoruh river valleys stands a second ridge that rises above 8,000 feet (2,400 metres).
Black SeaCove on a port along the coast of the Black Sea, Amasra, Turkey.© Boris Stroujko/Fotolia
The southern folded zone
The southern folded zone occupies the southern third of the country, from the Aegean to the Gulf of Iskenderun, from which it extends to the northeast and east around the northern side of the Arabian platform. Over most of its length, the Mediterranean coastal plain is narrow, but there are two major lowland embayments. The Antalya Plain extends inland some 20 miles (30 km) from the Gulf of Antalya; the Adana Plain, measuring roughly 90 by 60 miles (145 by 100 km), comprises the combined deltas of the Seyhan and Ceyhan rivers. The mountain system falls into two main parts. West of Antalya a complex series of ridges with a north-south trend reaches 6,500 to 8,200 feet (2,000 to 2,500 metres), but the most prominent feature is the massive Taurus (Toros) mountain system, running parallel to the Mediterranean coast and extending along the southern border. There crest lines are often above 8,000 feet (2,400 metres), and several peaks exceed 11,000 feet (3,400 metres).
In the eastern third of the country, the northern and southern fold systems converge to produce an extensive area of predominantly mountainous terrain, with pockets of relatively level land confined to valleys and enclosed basins, as are found around Malatya, Elazığ, and Muş. The central massif
The central massif is located in the western half of the country, between the Pontic and Taurus systems. This elevated zone is often referred to as the Anatolian plateau, although its relief is much more varied than this term suggests. At least four subdivisions of the central massif can be identified. Inland from the Aegean as far as a line from Bursa to Denizli, a series of faulted blocks gives a north-south alternation of steep-sided plateaus rising 5,000–6,500 feet (1,500–2,000 metres) and low-lying valley floors. Alluvial plains along the larger rivers, such as the Gediz, Küçükmenderes, and Büyükmenderes, are among the largest in Turkey and are of special agricultural value. East of this section, roughly to a line from Eskişehir to Burdur, is a complex upland zone. The general surface level rises to the east from 1,500 to 3,000 feet (460 to 900 metres); set into the upland are several downfaulted basins, and above it short mountain ranges rise to 6,500 feet.
Afyonkarahisar, TurkeyCity of Afyonkarahisar, Turkey, overlooked by a cone of volcanic rock.© Paul Kenward/AA Photo Library
The most distinctive part of the central massif is the area bounded on the south by the Taurus Mountains and on the northeast by a line from Ankara through Lake Tuz to Niğde. There the term plateau is most applicable, with large expanses of flat or gently sloping land at elevations of about 3,000 feet separated by low upswellings in the surface. Measuring some 150 by 200 miles (240 by 320 km), these are by far the most extensive plains in Turkey; however, their agricultural value is reduced by the effects of altitude and location on their climate.
The remainder of the central massif, a roughly triangular area with its eastern apex near Sivas, forms a mountainous zone that bounds the plains on their eastern side. Much of this section rises above 5,000 feet (1,500 metres), and there are numerous peaks with elevations of about 6,500 feet. A noteworthy feature is the extensive area of geologically recent volcanic activity in Niğde, Nevşehir, and Kayseri provinces, including the volcanic peaks of Erciyes (12,848 feet [3,916 metres]) and Hasan (10,686 feet [3,257 metres]). The Arabian platform
Southeastern Turkey between Gaziantep and the Tigris (Dicle) River rests on a stable massif called the Arabian platform. It is characterized by relatively gentle relief, with broad plateau surfaces descending to the south from about 2,500 feet (760 metres) at the mountain foot to 1,000 feet (300 metres) along the Syrian border. In the centre of this zone, the volcanic Mount Karaca reaches 6,294 feet (1,918 metres).
The geologic structure of Turkey—where recent faulting and folding are widespread and mountain building is still in progress—is particularly conducive to earthquakes, of which there have been many of varying intensity in modern times. A number of serious events have been centred in the east, near Erzurum in 1959 and 1966, Bingöl in 1971 and 2003, and Erzincan in 1939 and 1992. In 1999 the country’s northwest was struck by a powerful earthquake near İzmit (Kocaeli) that killed more than 17,000 people and evoked strong criticism of state institutions for their delayed response to the disaster. Drainage Rivers