One of the most industrialized areas of Turkey lies at the eastern edge of the Sea of Marmara, at the end of the Gulf of Izmit. The long, narrow waterway provides ship access to the cities of Izmit and Gölcük. This astronaut photograph highlights the metropolitan area of Izmit along the northern and eastern shores. Commercial and industrial centers—including petroleum refineries and automobile factories—are recognizable by large structures with white rooftops. The city of Izmit, then known as Nicomedia, was part of the Roman Empire and served as its easternmost capital before Constantinople (modern-day Istanbul) assumed that role in 330 AD. Izmit is located approximately 83 kilometers (52 miles) to the east-southeast of Istanbul.
The smaller city of Gölcük on the southern shoreline of the Gulf is the location of a Turkish naval facility and another automobile factory. Both urban areas are built primarily on flat lowlands adjacent to the Gulf, with green vegetation marking highland areas to the north of Izmit and south of Gölcük. Both the Izmit and Gölcük areas were severely damaged by a magnitude-7.4 earthquake on August 17, 1999, that resulted in over 17,000 fatalities. The earthquake occurred along the North Anatolian strike-slip fault that extends roughly east-west beneath the Gulf of Izmit.