Historic Earthquakes: Tectonic Summary

Magnitude 6.1 TURKEY
2003 January 27 05:26:22 UTC

Turkey is a tectonically active region that experiences frequent destructive earthquakes. At a large scale, the tectonics of the region near this earthquake are controlled by the collision of the Arabian Plate and the Eurasian Plate. At a more detailed level, the tectonics become quite complicated. A large piece of continental crust almost the size of Turkey, called the Anatolian block, is being squeezed to the west. The block is bounded to the north by the North Anatolian Fault and to the south-east by the East Anatolian fault. The recent earthquake occurred near the east end of the North Anatolian Fault. It is not known at present if the earthquake occurred on the North Anatolian Fault proper or on a related subsidiary fault.

This earthquake is a reminder of the many deadly earthquakes that Turkey has suffered in the recent past. The devastating Kocaeli (Izmit) earthquake of 1999 (M = 7.6) broke a section of the North Anatolian Fault 1,500 km to the west of this quake and killed 17,000 people, injured 50,0000, and left 500,000 homeless. Today's (January 27, 2003) earthquake occurred within or near the source region of the M = 6.6 earthquake of March 13, 1992, which killed hundreds of people and left thousands homeless in Erzincan. Another even larger earthquake struck Erzincan in 1939. The magnitude 7.8 earthquake killed an estimated 33,000 people. Erzincan is about 25 miles to the northwest of the epicenter of today's earthquake.