Sangchal (Bandpay) Earthquake of 02 July 1957, Mw7.0

At dawn on 11 Tir 1336, a destructive earthquake ruined the mountainous region of Bandpay, which is situated to the north of the drainage divide of the Alborz mountains. In the meizoseismal region, which lies between the upper courses of the Haraz and Talar rivers and comprises the dihistans of Bandpay, Beh and Dala Rustaq and Chalav, about 120 villages were totally destroyed with an estimated 1500 causalities. The heaviest destruction caused by the earthquake occurrred between Nandal, Sangichal, Chaliyasar, Nasal, Andavar and Pardimeh, while rockfalls and landslides added to the destruction particularly at Burun, Varzaneh, Shanguldeh, Nal and Dinan.  In the upper reaches of the Sajarud and Shir Qal’eh streams were dammed up and passes were blocked. A massive rockfall blocked the Haraz-rud near’Aliabad’, creating a twenty-meter high dam and a reservoir about one kilometer long. The damage sustained by the few engineering structures in the region, which can be found only along the Haraz road, was minor. The abutments of the eighty-meter long masonry spandrel arched bridge at Bayjan settled and its deck cracked. The lining of the road tunnel between Kuhrud and Bayjan was badly cracked and haunch sheared. There was also some damage to the short tunnel near the Nur confluence and to the abutments of the wooden bridge at ‘Aliabad’. There is no evidence that the earthquake was associated with surface faulting, and no changes in the fumarolic activity of the Damavand volcano were noticed. Outside the meizoseismal region, damage was widespread but not serious. It decreased more rapidly with distance to the northwest and southeast than to the northeast and southwest. It extended as far as Pul-i Safis, Shiragh and to the Kasiliyan river where at Utu a few houses collapsed. In the opposite direction at Pulur and Fasham a few roofs caved in and in the southern parts of Tehran a few houses were damaged. To the southeast a few houses were damaged as far as Firuzkuh. At Qaemshahr and Sari, in the opposite direction, a few modern houses were damaged and at babul the cross-branching of an elevated water tank snapped. The shock was felt from Khurasan and Shahrud to Hashtpar in Azarbaijan and as far south as Kashan. About 25 milion dollars worth of damage done and many sites and settlements in the region were totally abandoned. A small Imamzadeh at Vaneh and the Imamzadeh Hashim east of Ab’Ali were seriously damaged.