İzmit
İzmit is the capital district of Kocaeli Province in northwestern Turkey, located at the eastern terminus of the Gulf of İzmit in the Sea of Marmara, roughly 100 km east of Istanbul.[1][2] The district encompasses an area of approximately 480 km² and has a population of about 371,000 residents.[3] Founded in 264 BC as Nicomedia by King Nicomedes I of Bithynia on the site of earlier settlements, the city emerged as a key regional center under successive Hellenistic, Roman, and Byzantine rule, benefiting from its strategic position for trade and administration.[4][5] In modern times, İzmit stands as one of Turkey's premier industrial powerhouses, driving economic output through sectors such as automotive assembly, petrochemical processing, oil refining, and port operations, which underpin Kocaeli Province's leading position in national GDP per capita.[6][7][8] The region gained tragic prominence from the 1999 İzmit earthquake, which caused widespread devastation but spurred subsequent infrastructural advancements and seismic resilience measures.[9]Etymology
Historical Names
The site of modern İzmit was first settled by Megarian Greek colonists around 712 BC, who named the city Astacus after the nearby Gulf of Astacus (now İzmit Bay).[10] Some ancient sources also refer to it as Olbia during this early phase, reflecting its role as a coastal trading outpost.[10] The city was destroyed by Lysimachus, king of Thrace, circa 264 BC, prompting its reconstruction and renaming as Nicomedia by Nicomedes I of Bithynia, who established it as the capital of his kingdom.[11] This name, honoring the founder, endured through Roman imperial rule—where Nicomedia served intermittently as an eastern capital from 286 AD under Diocletian—and into the Byzantine period, underscoring its strategic position on trade routes linking Europe and Asia.[11] Following Ottoman conquest in 1337 AD, the Greek-derived Nicomedia gradually adapted into Turkish forms such as İznikmid or İzmgid, reflecting phonetic shifts in local usage.[12] By the late Ottoman era, particularly after administrative reforms in the 19th century, the name standardized as İzmit, a contraction emphasizing simplicity while retaining echoes of the ancient toponym; this form was formalized in Republican Turkey post-1923.[13] These evolutions trace a continuum from Hellenic foundations to Turkic integration, without evidence of abrupt impositions beyond conquest-driven transitions.[12]Modern Name
The modern Turkish name İzmit evolved from the ancient Greek Nicomedia (Νικομήδεια) via Ottoman Turkish variants such as İznikmid and İzmid, reflecting phonetic adaptation and administrative simplification over centuries.[14] After the Ottoman conquest of the region in 1327, official records predominantly used Iznikmid (or Iznikümid), though İzmid appeared concurrently, marking the initial Turkicization of the toponym.[14] By the 17th century, local inhabitants commonly referred to the city as İzmit, as documented in traveler accounts like Evliya Çelebi's Seyahatname, while bureaucratic texts retained Iznikmid until the mid-19th century when İzmid gained prevalence.[14] To resolve orthographic confusion with İzmir—exacerbated by similar Arabic-script renderings—the Ottoman administration formalized İzmit as the standard name in 1910.[14] This spelling persisted into the Turkish Republic, established in 1923, where İzmit became the official designation for the city, now the capital of Kocaeli Province.[12] The name's endurance underscores continuity in local usage despite historical shifts, without further alteration in the republican era.[14]Geography
Location and Topography
İzmit is located in Kocaeli Province, northwestern Turkey, at approximately 40°46′N latitude and 29°57′E longitude.[15][16] The city lies about 100 kilometers east of Istanbul, on the eastern shore of the Gulf of İzmit, an elongated inlet of the Sea of Marmara that extends roughly 55 kilometers eastward with widths varying from 2 to 10 kilometers.[1][17] The Gulf of İzmit divides the region into northern and southern sectors, with the city positioned at its northeastern head.[18] Topographically, İzmit occupies a constrained coastal plain fringed by steep hills and slopes, where much of the urban development has occurred on these inclines due to limited flat terrain near the water. The surrounding terrain features monogenetic relief rising from sea level to elevations exceeding 1,400 meters, with average slopes around 11 degrees.[18] City center elevations range from near sea level to about 95 meters, facilitating its role as a port while exposing it to seismic influences from adjacent fault lines.[19][20]Climate Characteristics
İzmit has a humid subtropical climate (Köppen Cfa), characterized by hot, relatively dry summers and cool, wetter winters moderated by the Sea of Marmara, though borderline Mediterranean influences appear in drier summer months.[21] [22] Annual average temperatures range from 6.4°C in January to 24.8°C in August, based on 1981–2010 data from the Turkish State Meteorological Service.[23] Summers from June to September feature average high temperatures exceeding 26°C, peaking at 30.5°C in August, with lows around 20.4°C; humidity rises, creating muggy conditions for about 14% of the time in August. Winters from December to February see average highs of 10–12°C and lows of 2–3°C, with occasional frost and snowfall, including a maximum snow depth of 90 cm on February 4, 1929. Precipitation averages 500–800 mm annually, concentrated in the wetter season from October to March (about 60–70% of total), while summers receive less than 50 mm per month on average; the highest daily total recorded is 169.4 mm on July 2, 1942.[23] [24] [25]| Month | Avg. High (°C) | Avg. Low (°C) | Avg. Precip. (mm) |
|---|---|---|---|
| January | 10 | 2 | 53 |
| February | 11 | 2 | 46 |
| March | 14 | 4 | 46 |
| April | 18 | 7 | 41 |
| May | 23 | 11 | 33 |
| June | 27 | 15 | 36 |
| July | 29 | 17 | 25 |
| August | 29 | 17 | 25 |
| September | 26 | 14 | 36 |
| October | 21 | 11 | 61 |
| November | 16 | 7 | 64 |
| December | 12 | 3 | 66 |