Yesterday's tragic earthquake in eastern Turkey is just the latest in a series of tectonic events that have impacted that region over the past 50 million years. Lying at the confluence of four tectonic plates, the Eurasian, African, Arabian and Anatolian, Turkey is one of the most geologically active regions on our planet.
Most of the country sits on the Anatolian Plate, a small continental plate that is surrounded by the other three larger plates. Fifty million years ago (MYA), as the Tethys Sea began to close, the African Plate drifted northward, colliding with southern Europe and forcing up the Alps and associated ranges. Then, about 30 MYA, the Red Sea began to open, shoving the Arabian Plate toward the northeast; its collision with the Eurasian Plate, which, like that between Africa and Eurasia, continues today, has crumpled up the Zagros Mountains of Iran. In eastern Turkey, the Arabian Plate is scraping along and pressing against the Anatolian Plate, forcing the latter to rotate counterclockwise, toward the west; in concert, across northern Turkey, the Anatolian Plate scrapes past the southern edge of the Eurasian Plate. Finally, along its southern rim, the Anatolian Plate interacts with the African Plate via a complex chain of transform faults, compression points and subduction zones.
As these Plates continue to rearrange themselves, pressure builds along the intervening fault lines and, though plate movement is in the order of only 3-10 mm per year, friction eventually fails and an earthquake results. Unfortunately, this pattern will continue and, like Los Angeles and Tokyo, Istanbul awaits a geologic catastrophe.
