Southeast Tabriz Earthquake of 26 April 1721, Mw=7.7

Southeast Tabriz Earthquake of 26 April 1721, Mw=7.7

Early in the morning of Sunday 26 April 1721, a major earthquake shook the region of Tabriz, killing at least 40,000 people. In Tabriz itself the shock ruined about three-quarters of the houses and caused substantial damage to most of the larger buildings which did not, however, collapse. Detailed information about the extent of the affected region outside Tabriz is lacking, but internal evidence suggests that the heaviest destruction, accounting for the large number of casualties, occurred within a zone that extended from near Tabriz to the southeast, through Shibli and beyond Qareh Baba. The shock triggered many rockfalls and was associated with a fault break that extended for at least fifty kilometers, from Tameh Dash to near Tabriz. The break through Shibli was still visible in 1809, and parts of the fault trace that seems to be connected with this earthquake can be seen today on the ground. The shock seems also to have been strongly felt in the Qazvin region and was followed by many strong aftershocks.