Monday 13 November 2017

Magnitude 7.3 Earthquake in Kermanshah Province, Iran.

The United States Geological Survey recorded a Magnitude 7.3 Earthquake at a depth of 23.2 km in about in Kermanshah Province, Iran, close to the border with Iraq, slightly before 9.20 pm local time (slightly before 6.20 pm GMT) on Sunday 12 November 2017. The event is thought to have caused at least 460 deaths and 6700 injured on both sides of the border, with the majority in Kermanshah Province. In addition around 7000 people are believed to have been made homeless. The quake was felt as far away as Ankara, Cairo, Jeddah and Dubai.

Damage to buildings in the city of Sarpol-e-Zahab in Kermansha following the 12 November 2017 Earthquake. Pouria Pakizeh/ISNA/AP.

Iran is situated on the southern margin of the Eurasian Plate. Immediately to the south lies the Arabian Plate, which is being pushed northward by the impact of Africa from the south. This has created a zone of faulting and fold mountains along the southwest coast of the country, known as the Zagros Thrust Belt, while to the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and creating frequent Earthquakes, some of which can be very large.

 The movement of the Arabian Plate and extent of the Zagros Thrust Belt. Rasoul Sorkhabi/Geo ExPro.

To the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and again creating frequent Earthquakes.

The population of Iran is particularly at risk from Earthquakes as, unlike most other Earthquake-prone nations, very few buildings in the country are quake-resistant. The majority of residential buildings in Iran are made of mud-brick, a building material particularly vulnerable to Earthquakes as the bricks often liquefy, trapping people inside and quickly asphyxiating them with dust. This is particularly dangerous at night when the majority of people are inside sleeping.

Section through the Zagros Fold Belt. Sarkarinejad & Azizi (2007).

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
 
See also...
 
http://sciencythoughts.blogspot.co.uk/2017/05/twenty-one-confirmed-fatalities.html
http://sciencythoughts.blogspot.co.uk/2017/08/magnitude-52-earthquake-in-hormozgan.html
 
http://sciencythoughts.blogspot.co.uk/2014/04/magnitude-50-earthquake-on-coast-of.html
http://sciencythoughts.blogspot.co.uk/2014/07/magnitude-47-earthquake-in-southeast.html
http://sciencythoughts.blogspot.co.uk/2014/01/magnitude-49-earthquake-on-coast-of.html
http://sciencythoughts.blogspot.co.uk/2014/04/magnitude-44-earthquake-in-khuzestan.html

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