The earthquake, which was among Iran's largest, measured 7.1 on the moment magnitude scale and had a maximum Mercalli intensity of IX (Violent).

A damaging foreshock occurred fifteen hours prior to the main event and served as a warning to the people that felt it strongly.

The epicentral area in the Salmas Plain covers 300 square kilometres (120 sq mi) and is positioned northwest of Lake Urmia.

This area had been inhabited primarily by Christians for about a thousand years prior to the event (which was one of the largest earthquakes to occur in Iran since 1900).

[4] The earthquake was a result of oblique-slip faulting, and was felt over a very wide area, from Leninakan in Armenia and Tbilisi in Georgia in the north, and Baghdad and Kirkuk in Iraq to the south.

In the zone of heaviest damage (bounded by the villages of Kohneh Shahr, Payajuk and Zaviehjuk) all the homes and all but one of the churches were destroyed.

To the east of this area, the large village of Dilman reportedly had 1,100 casualties, but seismologists J. S. Tchalenko and M. Berberian questioned the reliability of this figure.

The foreshock was also not strongly felt to the east of Lake Urmia (and to the southwest of Tabriz) where the village of Mamaqan was completely destroyed and 85 people were killed.

They estimated that about 30 kilometres (19 mi) of visible fault breaks were present immediately following the shocks, but by the time they had completed their survey 45 years later about half of the surface features had succumbed to erosion.