Earthquake

No one knows when the North Anatolian Fault will rupture, but one thing is certain: It will rupture. The resulting earthquake could be very bad news for the 12.8 million people in Istanbul.

For the past century, earthquakes on the North Anatolian Fault in northern Turkey have been creeping westward. The last big quake happened in 1999, when a 7.6-magnitude ((CONLINK|945|temblor devastated the city of Izmit)). The official death toll was around 17,000, but a 2004 estimate by University of Brasilia researcher Vasile Marza put the number at 45,000.

The next time the ground shakes, scientists expect that it will be even further west, just south Istanbul. A January 2010 study in the journal Nature Geosciences found that tensions along the fault are building and could trigger multiple small-to-moderate quakes. Or the fault could go all at once. In March, USGS geophysicist Tom Parsons told Nature that the chances of Istanbul being hit by a magnitude 7 or greater quake in the next 25 years are between 30 and 60 percent.