The Fars region of Iran was struck by a major earthquake on either 22 April or 5 May 1853. The city of Shiraz and the surrounding area were severely affected, with almost all buildings destroyed. At least 9,000 people were killed, with some estimates reaching 13,000.

Tectonic setting

Iran lies across the complex plate boundary where the Arabian Plate is

colliding In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...

with the Eurasian Plate. The Fars region lies within the outermost part of the Zagros fold and thrust belt. This Fars Domain is affected by the presence of thick Neoproterozoic salt of the Hormuz Formation, forming part of the so-called ''simply folded zone''. Despite its name, the folding is accompanied by

thrusting Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...

, with some

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

faulting, such as on the right-lateral Kazerun fault system. From the analysis of hypocentral depths and

focal mechanism The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is ...

s, the earthquakes are caused by both faulting within the underlying basement and towards the base of the thick sedimentary cover sequence. Almost all earthquakes occur on blind faults, with no surface rupture.

Earthquake sequence

The sequence began at about dawn on the day before the mainshock, with the first of a series of foreshocks. These continued throughout that day and into the following morning. The mainshock occurred at about noon, followed by a major

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...

six hours later.

Damage

The second foreshock caused severe damage in the Gawd-i Araban quarter, destroying a mosque, part of the bazaar and many houses, and causing widespread damage in the rest of the city. There was local ground liquefaction and some qanats collapsed. The third major foreshock, which occurred about 15 minutes before the mainshock, led to further damage, including the collapse of one of the minarets of the Masjid-i'Abbas mosque. The mainshock left the city devastated, all buildings and other structures within 12 km of the city were described as "ruined". Notable buildings that were either destroyed or severely damaged included the remaining parts of the Masjid-i'Abbas, the Shah Cheragh monument and mosque, the Armenian Church and the Madraseh Khan. Most of the Masjid-i Nau also collapsed, while the Masjid-i Vakil and the Vakil Bazaar were mainly unaffected. The major aftershock later that day led to further damage and casualties.

References

{{Earthquakes in Iran Earthquakes in Iran 1853 earthquakes 1853 in Iran April 1853 events Shiraz History of Fars Province