A newly released satellite image reveals Istanbul, the largest city in Turkey at 15 million inhabitants, is quickly becoming a "megacity" covering almost 700 square miles (1,800 square kilometers).
In this image, acquired by the German Aerospace Agency's TerraSAR-X radar satellite, the populated urban areas are colored yellow because the city's buildings reflect the satellite's signals, giving an accurate view of its immensity. [Amazing Science Images]
The city's airport is clearly visible in the bottom left corner of the image — the darker blue color indicates where there are few buildings around the runways. Even the boats are visible dotting the city's surrounding seas.
"These connections to the city center on the European side have generated enormous growth on the Asian side," Taubenböck said. "Over the last 35 years, the area of Istanbul has tripled."
Radar satellites like TerraSAR-X, which was launched in 2007, are useful because they can "see" through clouds and darkness, while typical remote-sensing instruments rely on visible light.
Over time, the population and urban sprawl of Istanbul has expanded immensely. The top image shows the population spread in 1975, the middle in 1990 and the bottom image is from 2010.
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