Bangladesh faced a significant tremor recently, with Dhaka and its surrounding districts experiencing a clear jolt that reminded the nation of its seismic vulnerability. The epicentre was identified near Madhabdi in Narsingdi, close to the heart of Dhaka -- an area already recognized for its population density and infrastructural challenges.
With a reported magnitude of 5.7 on the Richter scale, the earthquake was classified as moderate: Enough to rattle buildings and prompt evacuations, but not typically destructive in regions with resilient construction.
The earthquake that occurred is not an isolated geophysical event. Bangladesh has already experienced more than 10 earthquakes of various magnitudes this year.
The rise in frequency reflects the growing activity of the regional tectonic system within which the country is positioned. South Asia as a whole has seen a measurable increase in the number of moderate and strong earthquakes during the last decade.
Scientific assessments attribute this rise to the escalating stress along the boundaries of the Indian Plate and the neighbouring tectonic blocks that surround Bangladesh. The Indian Plate continues to move northward every year, and the collision with the Eurasian Plate has already created the Himalayan mountain chain.
The same movement is also building extreme levels of stress beneath the foothills of the Himalayas, which eventually releases through earthquakes of varying magnitudes.
The tremor that Dhaka felt represents a very small expression of this larger geological pressure.
Bangladesh is in a uniquely sensitive geotectonic location: Three significant directions of tectonic forces converge on the country. To the south, the Indian Plate pushes steadily northward. To the north and north east, the Himalayan front remains locked and highly stressed. To the east, the Burmese Arc and the associated microplates around Myanmar exert their own lateral forces.
As a result, Bangladesh sits on the front line of the collision between major tectonic systems that are constantly generating stress deep beneath the ground.
The latest scientific modelling repeatedly identifies Bangladesh as one of the few countries in the world that lies at the intersection of three major seismic source regions. These regions include the Himalayan collision zone, the Shillong Plateau region and the Arakan Subduction Zone.
The convergence of these three geological engines forms a natural setting where destructive earthquakes are not occasional events but inevitable features of the long term tectonic process.
The Arakan Subduction Zone is considered one of the most powerful earthquake generating regions in the world. It runs to the east of Bangladesh and subducts the Indian Plate beneath the Burmese microplate. Studies by international geophysicists show that this zone has the potential to generate earthquakes of magnitude eight or even magnitude nine when the locked segments rupture.
There is evidence that significant amounts of strain are accumulating here. If a major rupture occurs, the shaking would be felt throughout Bangladesh, including the capital.
Earlier scientific papers have already warned that the accumulated energy under the Arakan arc is comparable to the energy that once produced the Great Assam Earthquake of 1897. A similar event in the present context of dense urban development in Bangladesh would cause catastrophic consequences.
The eastern region of Bangladesh, especially around Chattogram and Cox’s Bazar, has shown increasing seismic activity during the last decade. A series of small to moderate earthquakes detected recently suggest that stress is shifting along the deeper segments of the subduction plates. Scientists describe this as a warning sign, because in many cases, a cluster of smaller quakes appears before a larger release of energy.
The possibility of a high magnitude earthquake, therefore, cannot be dismissed.
Arghya Protik Chowdhury is a student at the Department of Environmental Science, Bangladesh University of Professionals.
