On the morning of November 12, 2017, a violent earthquake of 7.3 on the Richter scale, the mountainous border between Iraq and Iran, was scared, leaving hundreds of dead and thousands of wounded, in one of the fiercest earthquakes in the region in recent decades.
Years have passed since the disaster, a team of Iraqi researchers returns to reveal the true cause of this earthquake, which is a “hidden rift”, which became scientifically known as the “Cracking of Khanaqin”, a discovery that can have a reflection in improving infrastructure and promoting statistical studies for earthquake monitoring in the region, says Dr. Abdel Aziz Mohamed Abdel Aziz, professor of exploration engineering and evaluation of classes in the Faculty of Engineering, Cairo University, who was not involved in the study in statements Especially for Al Jazeera Net.
What is “Khanaqin’s rift”?
And “Khanaqin’s rift”, is a geological crack that extends 125 km from northern Iraq to western Iran, and it follows a geological system known as “anthropic rifts”, which is a rift that occurs as a result of tremendous pressure that pushes the oldest rocks above the most recent at a low angle, and although it mostly extends inside Iranian territory, the researchers call it “Khanaqin” relative to the city of Khanaqin in eastern Iraq.
According to the study Published in the Journal of ASEAN Earth Sains, which was led by Dr. Farogan Khajik Cisacian, from the Petroleum Engineering Department at Kumar University of Science and Technology in the Kurdistan region of Iraq, this rift was not clearly visible on the surface before the earthquake.
It is called a metaphor for “hidden rift” because it is covered with layers of rocks that are difficult to distinguish with the naked eye, and it does not show clear superficial signals such as refraction or shown collapses, and it was not precisely specified on geological maps previously, before the devastating earthquake was revealed, and scientists pushed to reconsider the seismic activity in this region.
Revereging earthquake 2017
The earthquake struck on November 12, 2017 with a power of 7.3 degrees at a depth of 19 km, and its center was near the Iranian city of Serbal, and about 81 km from the Iraqi city of Khanaqin.
The earthquake caused the death of more than 630 people (most of them in Iran), 8100 others were injured, infrastructure was damaged in cities such as Darbandzhan and Halabja in Iraqi Kurdistan, and the Halabja water station stopped working by 50%, and recording more than 240 tremors.
In their study, the researchers relied on an advanced set of tools and technologies that included satellite images to monitor cracks and Earth changes, multi -standard geological maps for identifying overlapping rock formations, reviewing the earthquake archive in the region for more than 100 years, analyzing the effects of modern tectonic movement (neutolic activity), and led them all to clear evidence that the hidden Khanaqin rift is still active, It has been moving periodically for thousands of years.
Class coup .. the most prominent evidence
One of the most prominent evidences that revealed the continuous activity of Khanaqin’s rift was what the researchers noticed from the sliding movements of the rocks on both sides of the rift, it was found that the old limestone rocks, which were formed millions of years ago, have rushed strongly over the latest rocks from them, and this phenomenon, which is known as the “class coup”, occur Clearly in the form of folds (curves) and refraction (fractures) in the rocks can be seen on the surface of the earth.
To bring this scene closer, you can imagine that you put several leaves on top of each other, so that each sheet represents a layer of rocks, a time to the oldest to the latest. Now, if these leaves, especially the lower ones, are paid horizontally or from the lower side with a pressure force, whether side or over, the oldest leaves may slip above the latest leaves, which causes sleeping folds, very inclined ripples, and perhaps even ruptures in the upper leaves if they are sufficiently a curse, and this is completely similar to what happens in nature due to the rifts, but instead of the leaves, we are talking about layers An extended rock moves under the influence of tremendous pressure in the ground.
According to the study, “this type of slippage is one of the strongest evidence that the rift is still active, because such movements occur only when there are tectonic forces that still operate in the ground, which indicates the possibility of earthquakes in the future.”
3 modern tectonic indicators
In addition to slippage, the researchers monitored 3 modern indicators of the Tekton activity, the first of which is the presence of “sudden interruptions in the hills”, and this means the appearance of edges or sides of hills as if they were suddenly cut and straight, as if a huge “knife” separated part of the hill.
This indicates that an active rift “cut” the hill during its movement, and this type of composition is not only caused by natural erosion factors, but rather directly related to the active ground movements.
To clarify this effect, you can imagine a series of connected hills such as a series of adjacent chairs. If someone suddenly pushes the middle chair aside, the series will look like “cut off” at that place, and this is exactly what the rift does.
As for the second indicator, it is to monitor what is known as “twisting in the rock formations”, which are curves or twists in the layers of rocks that are supposed to be horizontal and straight, and these twists indicate that the rocks are subjected to constant pressure from the bottom or from the sides, which confirms that there is a tectonic movement that still occurs and presses the rocks slowly.
This is something that can be rounded, with a book with straight pages, then pressure is pressed from both sides, as a result of this bending some pages, and these bends are quite similar to what happens to the rocks when the cracks move.
Finally, the third indicator is the monitoring of an old, suspended, arrogant fans, and these fans are a gathering of water and torrents in the form of a fan on the ends of the mountains, and it consists of the deposits of clay and gravel, and when it stops receiving water or the path of the torrent changes away from it, it becomes “deserted”, and its presence indicates that the torrents changed by the height of the land or its deviation accident.
Energy south
Among the most prominent of what the results of this study monitored, along with the signs of modern tectonic activity, confirm that the November 2017 earthquake began in the north and headed to the south, meaning that the great energy has rushed towards the south, which explains the widespread damage that Iran witnessed compared to Iraq, and this phenomenon is known scientifically as “directing the rupture”.
This phenomenon occurs when the front that releases seismic energy moves in a specific direction during the earthquake, and it is similar to a bombing that occurs successively from one point to another, instead of exploding in all directions at the same time.
And when this front moves in a certain direction (for example from the north to the south), the areas in the direction of the movement (the south in this case) receives greater and stronger seismic energy, and since the seismic front moved from the north to the south, the greatest energy of the earthquake was heading towards Iran located south of the earthquake center, and not towards Iraq in the north, and therefore the damage was greater and the losses are more violent in Iran, even if some Iraqi regions were closer to Earthquake center.
A clear warning to the future
According to these results, the importance of this study lies in that it is not limited to explaining a past earthquake, but also carries a clear warning to the future, as Dr. Abdul Aziz Mohamed Abdel Aziz confirms.
He explains that this warning is that Khanaqin’s crack is still active, and millions of people live on its sides near the border, so revealing its hidden nature may save future spirits by improving infrastructure.
“With the knowledge of new information about the rift activity, such as the trend of seismic movement (for example from north to south), the buildings can be designed to withstand the most influential forces in that direction, for example, the walls and columns facing the direction of the movement can be strengthened to reduce the damage, and the vital infrastructure can be directed away from this direction or equipped with the improvements of earthquake resistance.”
It also indicates that “one of the benefits of this study is to document the tectonic activity in the hidden rift, which may contribute to developing more accurate statistical databases that help analyze the possibilities of earthquakes and their repetition, which supports better decisions in the field of prevention and preparation.”