Türkiye's geography: a plate pushed west between two faults

How two faults frame the Anatolian Plate

Most of Türkiye stands on a block of crust that is moving. Britannica describes the arrangement from the south: at the boundary of the Anatolian and Arabian plates, the Arabian Plate moves north at about 16 mm a year, and the horizontal compression it creates is slowly driving the Anatolian Plate westward. The smaller plate is bounded on the south by the East Anatolian Fault Zone and on the north by the North Anatolian Fault, which follows the Black Sea side of the country.

The rest of the boundary is recorded in the Wikipedia account of the country. To the east the plate meets the Bitlis-Zagros collision zone, to the south the Hellenic and Cyprus subduction zones, and to the west the Aegean extensional zone, where the crust is being pulled apart. The very severe earthquakes fall along an arc running from the Sea of Marmara in the west to Lake Van in the east. On the same account, around 70% of the population lives in the two zones of greatest seismic risk.

The General Directorate of Mineral Research and Exploration, the state geological survey known as MTA, published a renewed Active Fault Map of Türkiye in 2026. It was compiled from field mapping at a scale of 1:25,000 across the country's land area and includes the segments of some faults that continue beyond the frontier. MTA states that it is meant for regional hazard analysis, not for direct use in engineering.

What the northern fault did at İzmit

The North Anatolian Fault broke near İzmit, in the province of Kocaeli, on 17 August 1999. The magnitude 7.4 earthquake killed more than 17,000 people and injured 44,000. Britannica records that the delayed response drew strong criticism of state institutions. Since the İzmit and Düzce earthquakes of that year, the Wikipedia account records, activity on the North Anatolian Fault zone has been counted among the country's gravest natural hazards.

What broke along the East Anatolian Fault

The main shock struck at 4:17 in the morning on 6 February 2023, with a magnitude of 7.8, about 24 km south of Kahramanmaraş and at a focal depth of only 10 km. Where it started, the fault plane was nearly vertical, and rock on one side slipped roughly 8 metres along a front of about 300 km. A magnitude 7.7 event followed at 1:24 in the afternoon, about 48 km northwest of Kahramanmaraş, on the Çardak and Doğanşehir faults further north, and shifted the ground by up to 11 metres along a front of 180 km.

Model estimates put the damage zone of 2023 at some 350,000 km² across both countries, an area equal to about 45% of Türkiye's own. Nearly 46,000 people died in Türkiye in that earthquake, about 21,900 of them in Hatay province and 12,600 in Kahramanmaraş province. After the 2023 earthquake the Disaster and Emergency Management Presidency, AFAD, counted some 280,000 buildings severely damaged or reduced to rubble and another 710,000 heavily damaged.

Earthquakes of magnitude 6 or larger had been uncommon in the south since 1970, compared with the north, and that interval likely contributed to poor construction and weak enforcement of building rules in the region.

Why mountains wall the plateau on both sides

Structurally, Türkiye lies inside the young folded-mountain zone of Eurasia, and in Türkiye the folds trend mainly east to west. About a quarter of the surface stands above 1,200 metres, less than two-fifths lies below 460 metres, and flat or gently sloping land makes up barely a sixth of the total area. True lowland is confined to the coastal fringes. Britannica sorts the country into four structural regions: a northern folded zone, a southern folded zone, a central massif between them, and the Arabian platform in the southeast.

What the Pontic ranges do to the north coast

The northern folded zone is a belt of ridges 145 to 200 km wide immediately south of the Black Sea, rising in height towards the east. In the west the system has been fractured by the faulting that produced the Turkish Straits, and in Thrace the main range, the Yıldız, reaches only 1,030 metres. High ridges rise straight from the sea, so the coastal plain is narrow and opens out only in the deltas of the Kızılırmak and the Yeşilırmak. Those two rivers break through the mountain barrier at a weak point where the summits stay below 600 metres.

East of the Yeşilırmak the system turns higher, narrower and steeper. Less than 80 km from the coast the peaks pass 3,000 metres, and the Kaçkar range reaches its maximum there: 3,937 metres in Britannica and 3,971 metres in the Wikipedia regional account. The slope continues below the water, where the sea floor lies deeper than 2,000 metres along a line from Trabzon to the Georgian border. The Kaçkar above 3,000 metres was heavily glaciated during the Pleistocene. Behind the first wall, across the trough of the Kelkit and Çoruh valleys, a second ridge rises above 2,400 metres.

The parallel valleys running down to the Black Sea were isolated from one another until a few decades ago, because the forested ridges between them made transport and exchange so difficult. The Wikipedia account ties the survival of the Laz language, music and dance to that separation.

What the Taurus does to the south coast

The southern folded zone occupies the southern third of the country, from the Aegean to the Gulf of İskenderun, and then bends northeast and east around the northern edge of the Arabian platform. The Taurus runs parallel to the Mediterranean coast with crest lines often above 2,400 metres and several peaks above 3,400, among them Demirkazık at 3,755 metres and Aydos at 3,479.

The Taurus is more rugged than the Pontic ranges and less cut by rivers. In the western part of the region the rivers have not carved valleys through to the sea, and movement inland from that coast was historically hard except through passes such as the Cilician Gates, the Gülek Pass northwest of Adana. The coastal plain is narrow for most of its length and widens in two places: the Antalya Plain, which reaches about 30 km inland, and the Adana Plain, about 145 by 100 km, built from the combined deltas of the Seyhan and Ceyhan. East of Adana much of the coastal plain is limestone country with collapsed caverns and sinkholes.

What the interior plateau is made of

Between the two fold systems, in the western half of the country, lies the central massif. Britannica calls the term Anatolian plateau misleading, because the relief is much more varied than the word suggests, and divides the massif into at least four parts.

Inland from the Aegean, as far as a line from Bursa to Denizli, a series of faulted blocks alternates from north to south between steep-sided plateaus of 1,500 to 2,000 metres and low valley floors. The alluvial plains of the Gediz, the Küçük Menderes and the Büyük Menderes lie in those valleys and carry special agricultural value. The Wikipedia account places about half of the country's richest farmland in these broad, cultivated Aegean lowlands. East of them, to a line from Eskişehir to Burdur, an upland rises from about 460 to 900 metres, with downfaulted basins set into it.

The plateau proper lies south and west of a line from Ankara through Lake Tuz to Niğde, with the Taurus as its southern edge. Here the land is flat or gently sloping at about 900 metres, separated by low swells, across an area of some 240 by 320 km. Altitude and distance from the sea limit what those plains can grow. The Turkish word for the enclosed basins scattered across the plateau and through the folded mountains is ova. Some are only a widening of a stream valley; others, such as the Konya Ovası, are large basins of inland drainage or the product of limestone erosion.

The last part of the massif is a mountainous triangle with its eastern apex near Sivas, much of it above 1,500 metres. It holds the extensive area of geologically recent volcanic activity in the provinces of Niğde, Nevşehir and Kayseri, including the volcanic peaks of Erciyes at 3,916 metres and Hasan at 3,257.

Where the land rises highest in the east

In the eastern third of the country the northern and southern fold systems converge into one extensive mountain mass. Level land survives only in valleys and enclosed basins, such as those around Malatya, Elazığ and Muş. The western part of the region is the Anti-Taurus, where the average peak exceeds 3,000 metres, and the eastern part was historically known as the Armenian Highland. Many of the eastern peaks appear to be recently extinct volcanoes, to judge from their extensive lava flows.

Mount Ararat, called Ağrı in Turkish, stands close to the borders with Armenia and Iran. Its height is given as 5,137 metres in the country's record and in Wikipedia, and as 5,165 metres by Britannica. The two figures differ by 28 metres, and neither source says which survey it follows. In the far southeast Uludoruk Peak reaches 4,744 metres.

Lake Van lies in these mountains at an elevation of 1,546 metres and covers 3,714 km². It has no surface outlet. Winters in the region are severe: temperatures of −30 to −40 °C occur in the mountains of the east, snow may lie on the ground for 120 days of the year, and villages can be cut off for several days by a winter storm. The Aras, the Euphrates and the Tigris all rise in the Anti-Taurus.

Southeastern Türkiye between Gaziantep and the Tigris rests on the Arabian platform, a stable massif of broad plateau surfaces that descend from about 760 metres at the mountain foot to about 300 metres along the Syrian border. The volcanic Mount Karaca rises in its centre to 1,918 metres. Wheat and barley were the traditional crops, and irrigation projects begun in the 1980s widened what the region grows.

Why much of the water never reaches a sea

Britannica counts eight main drainage basins. The Aras rises south of Erzurum and flows east for some 400 km to the frontier with Azerbaijan, bound for the Caspian Sea. The Euphrates and the Tigris drain the bulk of eastern Türkiye and flow south for some 1,250 km and 530 km respectively before entering Syria and then Iraq, where they meet and run to the Persian Gulf.

Two basins drain inward. In the far east a small area drains to Lake Van. The main inland basin is in west-central Anatolia, centred on Lake Tuz and the Konya basin, with smaller separate catchments that hold lakes such as Eğirdir and Beyşehir. Where a lake forms inside such a basin it is usually saline, because the water has no outlet to the sea. Lake Tuz covers about 1,550 km² and is very shallow, expanding and contracting with the seasons. Türkiye placed the Lake Tuz Special Environmental Protection Area on its UNESCO tentative list in 2013.

The remaining basins drain to the four surrounding seas. Most Black Sea rivers are short torrents cut into the Pontic ranges, but several run long inland courses parallel to the ranges before breaking through. The Kızılırmak runs 1,355 km and the Sakarya 824 km in the Wikipedia regional account. Most of European Türkiye lies in the Ergene and Maritsa basin draining to the northern Aegean, and the Gediz and the two Menderes rivers flow west from the interior to the Aegean in parallel.

There are about 50 lakes larger than about 10 km² and more than 200 smaller ones. The freshwater lakes of the lake district on the north side of the Taurus include Akşehir, Eğirdir and Beyşehir. Hydroelectric development added artificial lakes behind the Atatürk and Keban dams on the Euphrates, the Hirfanlı on the Kızılırmak, the Sarıyar on the Sakarya and the Demirköprü on the Gediz. The rocks along the shore of Lake Salda were built by microbes, and in 2021 NASA reported that its minerals and rock deposits were the nearest match on Earth to those around Jezero Crater on Mars.

How mountains divide wet coasts from the interior

The coastal ranges stop Mediterranean and Black Sea air from reaching far inland, so the interior has a continental climate and the coasts do not. Wikipedia records 14 distinct Köppen climate zones in the country. Britannica calls the whole a dry, semicontinental variant of the Mediterranean climate, with winters much colder than the latitude would suggest.

The Black Sea coast receives rain in every season, with annual totals above 813 mm and reaching 2,438 mm in the east in Britannica, while the Wikipedia account gives about 2,500 mm for the eastern coast. The semi-arid centre of the plateau averages about 300 mm, and in a dry year the total may fall below 200 mm, with heavy losses of crops and livestock. Konya receives barely 305 mm. On the plateau May is usually the wettest month and July and August the driest.

The table gives Britannica's six regions. Temperature follows altitude as closely as rainfall does. January means are below freezing across the whole interior and below −5 °C over a sizable area of the east, while the coastal fringes stay above 5 °C. Snow cover lasts from two weeks in the warmer areas to four months in some eastern mountains.

The World Bank's Climate Change Knowledge Portal gives the national averages. Over 1995 to 2014 the mean annual temperature was 11.67 °C and annual precipitation 701.17 mm. Since 1970 temperatures have risen by 0.43 °C a decade and precipitation has fallen by 9.47 mm a decade, on the ERA5 reanalysis. For 2040 to 2059 under the high-emission SSP3-7.0 scenario, the median projection is a further 1.8 °C of warming, with a range of 1.36 to 2.74 °C, and a fall in annual precipitation of 34.22 mm.

Where Türkiye meets its neighbours and the straits

Britannica gives the total boundary as some 6,440 km, of which about three-quarters is maritime. The Investment Office of the Presidency gives the coastline as 8,300 km. The country stretches roughly 1,600 km from west to east and 480 to 640 km from north to south. The land frontiers rest on treaties signed between 1639 and 1939.

The Mosul settlement of 1926 traded the territory for 10% of its oil revenues over 25 years, and the Hatay transfer of 1939 followed a referendum.

The sea boundary is less settled than the land one. Most of the islands along the Aegean coast are Greek, and only Gökçeada and Bozcaada remain Turkish. Britannica records that the maritime boundary with Greece has been a source of dispute between the two countries on numerous occasions since the Second World War. This catalogue records the dispute and takes no position on it.

How the straits split Türkiye between two continents

Eastern Thrace, the European side, covers 3% of the surface and holds around 15% of the population. It is separated from Anatolia by the Bosporus, the Sea of Marmara and the Dardanelles, which Britannica groups as the Turkish Straits, the only outlet from the Black Sea. The Bosporus is about 25 km long and averages 1.5 km in width, narrowing to less than 1,000 metres in places, with banks that rise steeply from the water. The Dardanelles runs about 40 km and widens towards the south.

The area figure for the whole depends on the source. The country's record and the Wikipedia article on Türkiye give 783,562 km². The Wikipedia regional article gives 783,356 km², split into 756,688 km² in Anatolia and 23,764 km² in Thrace. Britannica gives 769,604 km².

What grows on the coasts and the steppe

Natural vegetation falls into two broad types. Steppe grassland covers central Anatolia and the southeast and reaches into lowland Thrace and the basins of the east; forest and woodland cover the rest. Over much of the country both have been heavily changed by lumbering, clearance for farming and grazing.

The Colchian forest grows on the eastern Black Sea coast, where rain is heavy, there is no summer drought and winters are mild. Hornbeam, sweet chestnut, oriental spruce and alder dominate it, over a shrub layer of rhododendron, laurel, holly, hazel and walnut. Conifers take over above 1,000 metres and alpine grassland above 2,000. The central and western Taurus carries Mediterranean mountain forest of pine, fir and oak with cedar and juniper. Along the Aegean and Mediterranean coasts the lowland vegetation is maquis of myrtle, wild olive, laurel and carob. Forest covered 29% of the surface as of 2020, and it includes large stands of the Lebanon cedar, Cedrus libani.

Three of the world's biodiversity hotspots overlap in Türkiye: the Mediterranean, the Irano-Anatolian and the Caucasus. Britannica lists wolves, bears, jackals, hyenas, gazelles and mountain goats among the wild animals still found in secluded and wooded country, and Angora goats graze the central massif.

Türkiye ratified the World Heritage Convention on 16 March 1983, and of its 22 inscribed properties, 20 are cultural and two are mixed. None is listed as natural alone. The two mixed sites are Göreme National Park and the Rock Sites of Cappadocia, inscribed in 1985, and Hierapolis-Pamukkale, inscribed in 1988. The natural candidates wait on the tentative list, which holds 80 entries, among them Lake Tuz, the Kızılırmak Delta wetland and the valley of Koramaz.