The 2010 Damghan earthquake (also known as the Kuh-Zar earthquake) occurred in northern Iran at on August 27 with a

moment magnitude The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...

of 5.8 and maximum

Mercalli intensity The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

of VII (''Very strong''). This strike-slip event damaged and destroyed a number of small villages in a sparsely populated region near the

Alborz The Alborz ( fa, البرز) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs nort ...

mountain range. It left four people dead, 40 injured, and about 800 without homes. The deaths and injuries in this moderate event were attributed to the low-quality construction styles that are typical of the area. The Iranian Strong Motion Network provided data by which seismologists determined the type and extent of the slip as well as the

peak ground acceleration Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a par ...

. Other large and destructive earthquakes have affected Semnan Province, including several events in 856 AD and 1953.

Tectonic setting

The tectonics of Iran are dominated by the continental collision of the Arabian and

Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...

s. The rate of

convergence Convergence may refer to: Arts and media Literature *''Convergence'' (book series), edited by Ruth Nanda Anshen *Convergence (comics), "Convergence" (comics), two separate story lines published by DC Comics: **A four-part crossover storyline that ...

has been estimated at two centimeters per year for the past 10 million years; about half of that occurs across the

Zagros fold and thrust belt The Zagros fold and thrust belt (Zagros FTB) is an approximately long zone of deformed crustal rocks, formed in the foreland of the collision between the Arabian Plate and the Eurasian Plate. It is host to one of the world's largest petroleum p ...

. The northern Iran region near the Alborz mountains contains numerous

reverse Reverse or reversing may refer to: Arts and media * ''Reverse'' (Eldritch album), 2001 * ''Reverse'' (2009 film), a Polish comedy-drama film * ''Reverse'' (2019 film), an Iranian crime-drama film * ''Reverse'' (Morandi album), 2005 * ''Reverse'' ...

and left-lateral strike-slip faults that lie to the south of the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

. The Astaneh strike-slip fault was a likely source of the

856 Damghan earthquake The 856 Damghan earthquake or the 856 Qumis earthquake occurred on 22 December 856 (242 AH). The earthquake had an estimated magnitude of 7.9, and a maximum intensity of X (''Extreme'') on the Mercalli intensity scale. The meizoseismal area (a ...

that caused the largest loss of life in the

history of Iran The history of Iran is intertwined with the history of a larger region known as Greater Iran, comprising the area from Anatolia in the west to the borders of Ancient India and the Syr Darya in the east, and from the Caucasus and the Eurasian Step ...

—more than 200,000 deaths. A more recent damaging event that also occurred near the

mountain range was the 1953 Torud earthquake, in which more than 900 perished.

Earthquake

Similar to the 1953 Torud earthquake, the 2010 Damghan event took place in a rural area that exposed relatively few villages to strong shaking. It occurred at 11:53 local time in the north-central desert region of Iran on a fault that dipped 78° to the northwest. Fault motion occurred on a NE–SW striking fault that was almost pure left-lateral strike-slip. A

of VII (''Very strong'') was observed in Kuh Zar and the nearby villages of Tuchahi, Kelu, and Shimi. In Hoseynian, Moalleman, Satveh, and Torud, the intensity was VI (''Strong''). Some surface cracks and

fissure A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure ...

s were present near Tuchahi and Kelu villages, but no significant

surface faulting In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where the ...

occurred.

Damage

The affected area has a low population density and has an abundance of homes that are constructed with local

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

material by unskilled workers. The unreinforced stone masonry or adobe homes are sometimes overloaded single story structures with flat wooden

roof A roof ( : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of te ...

s with steel beams. Most of these types of homes suffered partial collapse and led to a number of roof collapses. Fifty homes were destroyed, 300 were damaged, including a roof cave-in that left two women dead. Overall, seven villages sustained damage and twelve were destroyed. Four people died, 40 were injured, and 800 were left homeless, but no major infrastructure (

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

s, bridges, or power stations) were impacted.

Strong motion

The first

isoseismal map In seismology, an isoseismal map is used to show lines of equally felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no instrumental records exist, such a ...

that was created in Iran was for the earlier 1953 Torud event. To focus on the association between the macroseismic effects and the instrumental intensity for the 2010 event, seismologists Mohammad P. Shahvar and Mehdi Zaré conducted a field investigation and interviews. An isoseismal map that was created using the data aligned with a ShakeMap that was created by the Tehran-based

International Institute of Earthquake Engineering and Seismology International Institute of Earthquake Engineering and Seismology (IIEES) is an international earthquake engineering and seismology institute based in Iran. It was established as a result of the 24th UNESCO General Conference Resolution DR/250 under ...

. The closest strong motion station was about to the east of the origin of faulting and showed a horizontal acceleration of 0.55 '' g''. The peak ground acceleration and

peak ground velocity In seismology, strong ground motion is the strong earthquake shaking that occurs close to (less than about 50 km from) a causative fault. The strength of the shaking involved in strong ground motion usually overwhelms a seismometer, forci ...

that were attained from the Iranian Strong Motion Network were considered high for a moderate event.

Aftermath

Seventy rescue personnel and ambulances arrived at Kuh Zar. People with minor injuries were treated by paramedics and discharged; others were taken to Damghan Hospital. Interior Minister,

Mostafa Mohammad-Najjar Mostafa Mohammad Najjar ( fa, مصطفى محمدنجّار, born 2 December 1956) is an Iranian politician and retired IRGC general. He was interior minister of Iran from 2009 to 2013 and minister of defense in the first cabinet of Mahmoud Ahmad ...

, along with other government officials and members of the Iranian Red Crescent Society (IRCS), visited Kuh Zar the following day. A temporary camp with 50 tents was established in the village. Food, beds and other necessary items were supplied to the village by the IRCS.

References

Sources

External links

M5.8 – northern Iran
–

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

5.9 magnitude Damghan earthquake, 27 August 2010
– Geological Society of Iran * {{DEFAULTSORT:2010 Damghan earthquake Earthquakes in Iran 2010 earthquakes 2010 in Iran History of Semnan Province August 2010 events in Asia 2010 disasters in Iran