Expert urges Karachi to prepare for earthquakes, says city lies near three-plate junction and multiple faults
A magnitude 5.2 earthquake that struck Karachi on Tuesday night originated from the Sonmiani area of Hub district, where three tectonic plates meet: the Arabian Plate, the Eurasian Plate and the Indian Plate. This fact calls for caution on the part of Karachi residents.
Tectonic plates are massive, irregularly shaped slabs of solid rock that form the Earth’s lithosphere (crust and upper mantle) and move slowly over the asthenosphere (semi-molten rock beneath them) driven by internal heat.
Speaking to The Express PAkGazette, National Seismic Center director Ameer Haider Laghari said the earthquake was caused by a movement in the Arabian Plate at the junction.
Read: 5.2 magnitude earthquake reported in Karachi
“As a result, tremors and vibrations were felt in many areas of Karachi. Fortunately, the intensity and depth of the earthquake were low,” he said, adding that the place near Sonmiani where the earthquake originated also has no human settlements.
According to Laghari, this was not the first time that an earthquake of this magnitude had been recorded, slightly higher on the Richter scale than the tremors of the recent past.
However, he cautioned, this does not mean people should become completely complacent. Previously, a 5.0 magnitude earthquake was also recorded in 2020.
He said the faults and tectonic boundaries near Karachi are mostly located at shallow depths, where very high intensity earthquakes have never been recorded.
A fault is a fracture or zone of fractures in the Earth’s crust where blocks of rock move relative to each other, releasing stress in the form of earthquakes or slowly through creep.
Karachi is located near several active faults, including the local Landhi fault, the Malir fault and the nearby Hub fault, influenced by the tectonic boundary of the Arabian, Indian and Eurasian plates.
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Experts identify about five active faults in the surrounding area, with recent minor tremors often releasing energy along the Landhi-Korangi fault.
Laghari emphasized that whether an earthquake occurs at sea in the form of a tsunami or on land, basic preparedness training is extremely important, and earthquake-resistant construction is equally essential and requires a special approach.
According to him, a micro-level study on earthquakes in Karachi was also carried out during the current year. “Several earthquakes on the Richter scale were recorded during this study, although people could not feel them due to their low intensity,” he said.
The expert stated that earthquakes were also recorded here in the 18th and 19th centuries; However, modern instruments were not available at the time, so its intensity was not recorded.
Previously, there were forests and orchards along the faults, but now vast areas are densely populated, a fact that Laghari says must be taken into account when making plans to prevent earthquake-related incidents.
He noted that people in Japan also live near fault lines, but their construction practices take this natural process into account.
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“It is necessary to formulate an appropriate policy to ensure that construction near faults is earthquake-resistant, or that construction and civil works meet standards capable of withstanding earthquakes,” he said.
In the middle of this year, 57 earthquakes were recorded in a period of 23 days along the Korangi-Landi fault, while in 2009, approximately 36 earthquakes were recorded in a period of four months.
