North Anatolian Fault
The 900 km long North Anatolian Fault ( also North Anatolian fault zone, North Anatolian fault, or North Anatolian Fault Zone ) is a transform fault which limits the Anatolian plate northward against the Eurasian plate. It extends across the north of Turkey and the Marmara sea to Greece. Along its course, it always comes back to earthquakes. As the herd of these quakes are often only at shallow depths, although they are localized close, but still very strong. The last major earthquake was in 1999, the earthquake in İzmit; while some 18,000 people died.
Explanation
Earthquakes in Greece and Turkey also make the now 50 million years lasting active collision of the continental plates of Africa and Europe visible. But instead of the subduction zone, which is south of Crete arose, run in Turkey, the plates against each other ( transform fault ). This causes the edges of the collision zone to crumple and break. These fragments of the continents then move detached as microplates. The Anatolian microplate is an example of such fragments. They sandwiched between Europe and the emerging north Africa and moves with two to three centimeters per year westward. While wandering the central part of Turkey to the west with, but an area of the northern border is stuck in Asia and there hooked on the North Anatolian Fault. This part remains, then jerkily hinterherzuspringen once the voltage has become too large.
Similar phenomena
The San Andreas Fault in the western U.S. is often used for comparison, because it is a transform fault and the North Anatolian fault is similar to her in many ways. On the one hand are both right -lateral faults: that is, a person looks during an earthquake on such a right -lateral fault, the him opposite side moves to the right. This sense of movement is observed for both faults. Moreover, they are similar in length and cause severe earthquake with a high magnitude. Similar to San Francisco on the San Andreas Fault, which was destroyed in 1906 by a strong earthquake, the metropolis of Istanbul is under severe threat from North Anatolian Fault.
Threat to Istanbul
Despite its proximity to the North Anatolian Fault (only 20 km ) Istanbul 1766 was last hit by a severe earthquake. Scientists at the GFZ Potsdam calculated together with their Turkish colleagues from the Kandilli Observatory Earthquake Research a probability of 60 percent for a large quake in the next three decades.
Even during the last one hundred years indicated a series of severe, of shifting to the west earthquake events indicate that Istanbul is imminent an early quake.
The above-mentioned earthquake in Izmit, just 80 kilometers east of Istanbul, was an additional warning signal. A large fault can not move along its entire length at once because, to the frictional resistance is much too large. Instead, the earth tears in sections - in the case of the İzmit earthquake, at 130 kilometers in length. However, this depends not only to relieve the pent-up tension on the spot, but also a stress concentration at the end of the active portion of the fault. There is then, years or decades later, triggered the next quake. Earthquake researchers are actively working in Istanbul and try to the impending quake best prepare. In order to geological can understand the individual processes better, they have built stations around the Marmara Sea and also done research on the bottom of the sea. Although it is not in a position to warn the population in time, however, automated systems are now installed, close the case of the earthquake gas lines, bridge pose on red traffic lights or to stop trains.
In 2013, a 30 -kilometer-long tension zone is less than 20 kilometers from Istanbul was discovered after four years of measurements.