Farsinaj Earthquake of 13 December 1957, Ms7.1
An earthquake of magnitude Ms=7.6 and mb=6.5 occurred in the Farsinaj region of Kermanshah province in Iran on Friday Morning, Dec. 13, 1957, at 5:15:00 a.m. local time, (1:45:00 GMT). The epicenter of the earthquake was located at 34.35°N and 47.67°E with about 35 km depth. A filed investigation carried out 16 years later (Ambraseys et al, 1973) shows that this earthquake caused heavy damages within an area of 2,800 square kilometers in which 1,119 people were killed and left 900 injured and 15,000 homeless. Macroseismic evidence suggests a somewhat more moderate epicentral intensity of VII+ (MMI).
With the exception of a single aftershock which preceded the main earthquake by about 26 hours and which was strongly felt at Kangavar, records of the nearest seismological stations show no trace of important seismic activity in this part of the Zagros during the preceding four months.
The earthquake and its numerous aftershocks destroyed or damaged beyond repair 5,000 housing units out of a total of about 9,000 (more than 55%). Most of the local type of dwellings were one-storey adobe or rubble masonry houses set in mud and covered with heavy flat roofs of tamped earth. In the larger villages there were a few two-storey adobe houses as well as some one-storey brick masonry buildings covered with Iranian jack-arches or with light roofs of galvanized iron sheets.
A reconnaissance survey disclosed a fracture between Karaj Olia and Karkasar, probably of tectonic origin. As a matter of fact, there was linear topographic features in the form of terraces bearing 130°E. These fractures, which are mainly in alluvium, suggested very recent normal faulting and showed no evidences of lateral motion.
