Tabriz Earthquake of 08 January 1780, Ms7.7
Preceded by a strong foreshock, a catastrophic earthquake on the night of Friday to Saturday 8 January 1780 in the region of Tabriz almost totally destroyed the city and devastated about 400 villages, including Marand, Tasuj and Iranaq. The magnitude of the earthquake was Ms=7.7 and the epicenter was located at 38. 2N and 46E. In Tabriz itself, all major buildings, weakened by previous shocks, were ruined and all private houses, as well as the fort and walls of the city were totally destroyed, the radius of destruction being variously given as 72 or 120 kilometers from Tabriz. Vast numbers of people perished in this earthquake, estimates ranging to over 200,000. The number was probably somewhere around 50,000.
The earthquake was associated with a fault break at least sixty kilometers long that extended from the vicinity of Shibli in the southeast, to near Marand in the northwest. Contemporary reports show that faulting extended from northeast of Tabriz, in the foothills of the Surkhab (Ain Ali) mountains, for about 45 kilometers, heading southeastwards to Shibli. On Surkhab, the fault break is described as 2 meters wide heading for 12 kilometers in a southeasterly direction, while to the northwest of Tabriz the break is described as a 15 kilometer scarp 4 to 10 meters high, facing southwest and clearly distinguishable by its grey color, heading in a northwesterly direction.
In the low-lying region to the west of Tabriz, the soil liquefied and mud was ejected from the ground. The shock caused springs and qanats to dry up and new streams to flow elsewhere, in some places in such quantities that it threatened to flood the devastated area. The water ceased to flow after about 2 hours, draining off towards lake Orumiyeh. About 12 kilometers east of Tabriz, the earthquake caused extensive slumping and sliding of a large area of grassland.
The earthquake was responsible for the destruction of all the historical buildings in Tabriz such as Friday Mosque in the bazaar, the mosque of Alishah (now is named Arg-e Ali-Shāh) and also Blue Mosque of Tabriz (Ambraseys and Melville, 1982).