NW Shiraz Earthquake of 25 June 1824, Mw=6.4
At dawn, on 25 June 1824, a destructive shock occurred in the district of Shiraz. In the city itself, all houses were damaged and a few collapsed. The eastern city walls and nearly all its towers fell down, and the rest of the fortifications were damaged. Of the public buildings, those constructed during the period of Karim Khan-i Zand, such as the bazaar and the Masjid-i Vakil, suffered minor damage. The dome and walls of the Imamzadeh Shah Chiragh, the Madraseh Khan, the Imamzadeh of Shah Mir Hamza and Sa’id Ahmad, as well as part of the palace, collapsed together with several minarets. There is no evidence that damage extended beyond Shiraz, except to the district of Guyum in the northwest where a number of villages, including Kilistan and Qalat-i Guyum, were ruined and a few hundred people were killed, some of the survivors removing to Shiraz. Damage extended as far as Shul. The shock was felt strongly at Bushire and Imamzadeh Isma’il, and as far as Yazdikhwast, about 190 kilometers from the meizoseismal region. The earthquake caused a permanent rise in the underground water table in the region of Shiraz, and it was followed by aftershocks for six month. A shock on 28 August caused additional damage near Shiraz.
Golbaf Earthquake of 11 June 1981, Mw=6.6
This earthquake killed about 1071 people, most in the main settlement of the remote desert town of Golbaf in southeast of Iran. All the villages in the Golbaf playa were heavily damaged. No foreshocks or preceding regional seismic activity were detected by teleseismic networks, and the general level of seismicity on the Gowk fault system had been low since the last moderate shock of 2 September 1969 (mb 5.2). Local inhabitants reported no indication of seismic activity in the epicentral region during the hours or days preceding the 11 June earthquake. The 11 June 1981 earthquake was associated with right-lateral reverse displacement along faults bounding the Golbaf depression and dipping both east and west along the Gowk fault system. The eastern fault moved over a length of about 14.5 km at the surface south of Golbaf, with an average of approximately 3 cm right-lateral and 5 cm vertical motion. The western fault appeared to have moved over a length of about 7.5 km southeast of Golbaf with only small displacements and hair-line cracks visible at the surface.