Severe earthquakes occur again and again in Iran. Particularly in rural areas the simple loam houses are often badly damaged. The photograph was taken near the towns of Ahar and Varzagan in August 2012. (Photo: Mardetanha/CC BY-SA 3.0/Wikimedia)

Somewhere on the Earth an earthquake is always occurring. On April 16, 2013 a violent earthquake of magnitude 7.7 shook the border region between Iran and Pakistan. Seismologist Frederik Tilmann from the GeoForschungsZentrum in Potsdam (German Research Centre for Geosciences - GFZ) in an interview with “Zeit Online“ on the high-risk region of Iran, the danger of earthquakes for humans and the reliability of measurement data.

The earthquake occurred east of the Iranian town of Khash at a depth of 73 kilometres. The effects could be felt as far as the Indian capital of New Delhi. Dozens of people in Pakistan lost their lives, a large number were injured and hundreds of houses were destroyed. It was the most severe earth­quake in Iran for 40 years. Only on April 9, 2013 had an earthquake of magnitude 6.4 southeast of the town of Bushehr shaken southern Iran. The reason for the comparatively low number of deaths due to such a severe earthquake was the sparsely populated border region between Iran and Pakis­tan in which the epicentre was located.

Iran is a “high-risk area for earthquakes“, explains Tilmann. The reason is the course of several tec­tonic plates below the country. At the Gulf of Oman, the origin of the earthquake, one plate shifts below another, which is why “very deep earthquakes” occur in this region. “But also these can have devastating effects on the surface“, says Tilmann. Particularly in Iran deaths occur again and again as a result of earthquakes. Tilmann explains that this is due to the “rural loam construction method“, which is in extreme danger of collapsing in the event of tremors, and the modern buildings in the cities and towns which are not usually constructed to withstand earthquakes. And so “even not so severe earthquakes can claim a comparatively large number of lives.“

When analyzing earthquakes such as those occurring in Iran and Pakistan the GFZ does not have to rely on measurement data from Iran and Pakistan. “It is sufficient to evaluate the data recorded by seismometers all over the world in order to come to conclusions as regards earthquakes”, says Til­mann. For the secondary earthquake a magnitude of 4.5 was calculated. Current earthquakes are continuously recorded and published at the GFZ.

Read the whole interview with Frederik Tilmann at Zeit Online:
http://www.zeit.de/wissen/umwelt/2013-04/erdbeben-iran-forscher

Übersichtskarte über die Erdbeben im April 2013 im Iran. Die Plattengrenzen und Epizentren sind in rot eingezeichnet.
Map of earthquakes in April 2013 in Iran. The plate boundaries are shown in red. (Map: Wissensplattform eskp.de, Licence: CC BY 4.0)