Swarm of earthquakes hit Karachi: Is the great Himalayan earthquake coming?

India Today

20 hours ago

In the last few days, Pakistan experienced a series of earthquakes especially in the areas near Karachi. The multiple tremors created panic among the locals and simultaneously raised questions about the high frequency of these activities.More than 20 smaller earthquakes, which have magnitudes of around 3 on the Richter scale, are not a matter of worry, but the question is whether these are warnings for a bigger earthquake in the region.advertisementIt is not just about Pakistan; geologically, even the adjacent Indian states are similar. Hence, another question that hits the mind is whether earthquakes near Karachi are a matter of worry for our country.Why did these quakes occur in Karachi?
A series of low-intensity earthquakes, primarily in Karachi, Sindh, highlights the region's seismic vulnerability due to its location near the boundary of the Indian and Eurasian tectonic plates.
Collisions of two tectonic plates drive frequent earthquakes in the region. (Photo: AFP)
Karachi, one of the largest cities of Pakistan, was struck by almost two dozen earthquakes with magnitudes ranging from 2.5 to 3.6 between June 1 and June 3.advertisementAccording to seismological experts, quakes were driven by natural tectonic activity along the Indian-Eurasian plate boundary, specifically associated with the Landhi Fault Line in Karachi.Pakistan's location at the convergence of these plates makes it prone to frequent seismic events, with Karachi typically experiencing lower-intensity quakes compared to the north of Pakistan. These "swarm earthquakes" indicate a seismic risk near Karachi, despite being seismologically less active than northern Pakistan.The Landhi Fault Line's activity suggests local fault dynamics, potentially triggered by stress redistribution in the region's tectonic framework.Are back-to-back earthquakes normal?Pakistan and the Indian part near the Himalayas are tectonically active and prone to seismic activity. Pakistan lies at the convergence of the Indian and Eurasian plates, with Sindh, Punjab, and Jammu and Kashmir on the Indian Plate, and Baluchistan, Khyber Pakhtunkhwa, and Gilgit-Baltistan on the Eurasian Plate.Collisions of these two plates drive frequent earthquakes in the region, particularly at the fault lines of plates like the Landhi fault near Karachi. Geologists consider that these earthquakes can be viewed from two different points of view.Dr Shahsank Shekhar, Professor of Geology at Delhi University, explains the phenomenon, "Normally, when multiple earthquakes of relatively lower frequencies come to an area, then two kinds of interpretation can be drawn. The first, small earthquakes are a good sign as the stress is being released slowly. But another interpretation says that there is a stored stress between the fault lines, and a bigger earthquake can result if that stress energy comes out in one go."
Quakes were driven by natural tectonic activity along the Indian-Eurasian plate boundary. (Photo: Getty)
What could be the possible reasons for swarm earthquakes?There are a variety of reasons for multiple earthquakes in any particular area. In addition to tectonic plate movements, fault networks and stress transfer, and aftershocks after a major earthquake, there could be other reasons as well.These reasons include Fluid movement, like Magma or groundwater flowing through the Earth's crust. Regions near active volcanoes may experience earthquake swarms due to magma movement or volcanic unrest. For example, swarms often precede or accompany eruptions in places like Iceland or Hawaii. Some regions, like the Mediterranean or the Ring of Fire, are seismically active due to their location near multiple plate boundaries or fault zones.advertisementInteractions between these faults can lead to clusters of earthquakes.