LAHORE: Around 20 low-intensity earthquakes jolted Pakistan in the first half of February — an average of more than one tremor each day.
While recurring reports of quakes tend to make people anxious, experts say these minor seismic activities are actually a silver lining.
Such jolts “preempt” high-intensity earthquakes by constantly releasing accumulated energy within the plates.
In the Himalayan region, major seismic activity takes place on a roughly 100-year cycle, experts told Dawn.
The last major seismic events in the region were the earthquakes of 2005 and 2015.
Pakistan shifting towards satellite tracking to monitor seismic activity, improve early warning capabilities
The former claimed around 80,000 lives in northern Pakistan, while the latter caused widespread damage in neighbouring Afghanistan.
Eighty years earlier, the city of Quetta was levelled by a seven-magnitude quake, killing nearly 35,000 people.
The interluding minor tremors between major events break the momentum, preventing a sudden and bigger release of energy, according to experts monitoring the movements of tectonic plates.
Tectonic positioning
Pakistan falls on three major tectonic plates — the Arabian, Euro-Asian and Indian — which lift, subduct and provide energy and movement to each other, explains Muhammad Rehan, a geological engineer.
Sindh and Punjab lie on the Indian plate, while the western parts of Balochistan and some areas of Khyber-Pakhtunkhwa sit on the Eurasian plate, which mainly comprises the Iranian plateau and touches the Indian plate.
This creates five seismic zones under Pakistan. The intersection of multiple fault lines means tectonic movements remain a frequent occurrence in the region.
The quantum of this activity can be gauged by the fact that around 978 aftershocks were recorded after the 2005 earthquake. By the year’s end, the number of aftershocks reached a staggering 1,778.
Since then, satellite data has shown the mountains above the epicentre have risen by a few meters.
The movement and formation of mountains are linked with earthquakes as the seismic activity pushes the rocks up, creating giant, steep structures.
“This movement of the Himalayas shows they are still in a formative stage. In other words, the very region where Pakistan exists is still being formed and is fluid,” Mr Rehan explains.
‘Routine matter’
According to Volcano Discovery, a website monitoring earthquakes, the intensity of 11 of the 20 jolts reported in February was over four on the Richter scale. Seven of them fell between three and four intensity scale and two between two and three.
Since January, major urban centres, including Islamabad, Rawalpindi, Quetta, Swat, Zhob, Sherani, Sibi and Kalat, have been hit by tremors of varying intensities.
