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 Mwg, 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. was defined in a 1979 paper ...

of 5.8 and maximum Mercalli intensity 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 ( ) 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 northeast and merge ...

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 wikt:accelerogram, accelerogram at a ...

. 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 In geology, continental collision is a phenomenon of plate tectonics that occurs at Convergent boundary, convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroy ...

of the

Arabian The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

and Eurasian plates. 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 ...

. The northern Iran region near the Alborz mountains contains numerous 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, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...

. The Astaneh

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 ...

fault was a likely source of the 856 Damghan earthquake that caused the largest loss of life in the

history of Iran The history of Iran (also known as Name of Iran, Persia) is intertwined with Greater Iran, which is a socio-cultural region encompassing all of the areas that have witnessed significant settlement or influence exerted by the Iranian peoples and ...

—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 A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

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 Mercalli intensity 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 A ...

s were present near Tuchahi and Kelu villages, but no significant surface faulting 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. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

material by unskilled workers. The unreinforced stone masonry or

adobe Adobe (from arabic: الطوب Attub ; ) is a building material made from earth and organic materials. is Spanish for mudbrick. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is use ...

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 tempera ...

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, aqua ...

s, bridges, or power stations) were impacted.

Strong motion

The first

isoseismal map In seismology, an isoseismal map is used to show Contour line, countour lines of equally felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no seismometer ...

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. 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 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 An interior minister (sometimes called a minister of internal affairs or minister of home affairs) is a Cabinet (government), cabinet official position that is responsible for internal affairs, such as public security, civil registration and iden ...

, Mostafa Mohammad-Najjar, 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), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

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 in Asia 2010 disasters in Asia 2010s disasters in Iran