Dual earthquake decoding in Iran

Double seismic in Iran occurs due to two stratigraphic plates rubbing each other horizontally. They are close to the ground so they can cause great damage to people and materials.

>>>Iran: Hundreds of people died from double earthquakes

Iranian officials announced many aftershocks continued to appear in the northwest of the country after two earthquakes occurred on August 11 that killed 306 people and injured more than 3,000 people.

Two earthquakes, with magnitude of 6.3 and 6.4 Richter scale, appear about 10km apart. This is an unusual phenomenon, because according to the US Geological Survey, the northwestern region of Iran only suffered seven earthquakes with magnitudes of 6 or more Richter levels in the past 40 years.

Gavin Hayes, a researcher at the US National Earthquake Information Center, said northwestern Iran faces a high risk of earthquakes, although it is not on the boundary between two stratigraphic plates, Livescience said. know.

'This area is a plateau once raised by the convergence of Arab tectonic plates and Eurasian tectonic plates. So it has a lot of milling lines (broken lines) and has experienced many earthquakes in the past , 'Hayes said.

The earth's crust is not a healthy mass but cracked into many parts. They often collide and rub against each other. Arab tectonic plates form Saudi Arabia, Yemen, and Oman and stretch to northern Syria, Iraq and southern Turkey. As it is moving north, it rubs against Eurasian strata, which make up most of Asia and Europe.

The map shows the intensity of shaking from an earthquake with intensity
The 6.4-magnitude Richter occurs in Ahar, Iran on August 11, 2012

Double seismic on August 11 is earthquakes created by oblique rubbing, meaning that two tectonic plates move almost horizontally. Such earthquakes often occur quite close to the ground so people always feel the earth shake very strongly.

Aftershocks with a magnitude of 4 or more Richter often appear a few weeks or months after the earthquake caused by oblique rubbing.

Earthquakes in northwestern Iran are often less than 7 on the Richter scale, Hayes said. But because construction works in this area are of low quality, earthquakes of 6 to 7 Richter scale can cause great damage to people and property. The media reported countless villages flattened after the double earthquake.

'Right after the shallow earthquake occurred in northwest Iran, we all know that hundreds of people will lose their lives,' Hayes said.