Why is Iran prone to earthquakes?

Iran is one of those regions of the world that is all too familiar with quakes, and has experienced some very big tremors in the past.

In general terms, the big driver here is the clash between the Arabia and Eurasia tectonic plates. The former is pushing north by a couple of centimetres a year.

In the south-east of the country, the Arabia plate is actually pushing under the Eurasia plate, but in the north-west these great slabs rub directly against each other. The Zagros mountains are a result of all this compression.

Early reports indicate the quake occurred on a thrust fault. This means the crust on one side of the break in the rocks is moved vertically up and over the other side – which fits exactly with this general picture.

Geological agencies now produce immediate bulletins on the likely expected casualties. This modelling work is based on factors such as the size of the quake, population density and what is known about local construction methods.

It’s inexact work, but the first bulletins suggested this event could produce many hundreds of deaths and perhaps thousands of injured individuals.