Country not at risk of major earthquake

The earthquake risk of the basin is not rationally anticipated due to the absence of adequate seismic and geodetic data...

— Mir Fazlul Karim Engineering geologist, Geo Eastern Inc, USA

Bangladesh is not at risk of a massive 9.0 magnitude earthquake, said speakers at a seminar yesterday, contradicting the anticipation of a massive earthquake made in a 2016 study.

"The earthquake risk of the basin is not rationally anticipated due to the absence of adequate seismic and geodetic data, sub-surface geological maps, insufficient representation and instrumental data acquisition system," said Mir Fazlul Karim, engineering geologist, Geo Eastern Inc, USA.

He also suggested a collaboration between scientists and researchers to find out the location of faults, the scenario of sediments and the actual possibilities of mega earthquakes.

Fazlul made the observation at a seminar, titled "Understanding the Structure and Tectonic Configuration of Bengal Basin for Earthquake Magnitude Prediction", organised by Dhaka University's geology department.

The 2016 study, titled "Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges", by Michael Steckler -- a geophysicist at the Lamont-Doherty Earth Observatory at Columbia University -- mentioned that the northeastern corner of the Indian subcontinent is actively colliding with Asia, potentially posing a risk of an earthquake with a magnitude of 8.2 to 9 in the region.

A 9-magnitude earthquake is equivalent to 8 billion tonnes of explosives, said Fazlul, also the former director of Geological Survey of Bangladesh.

"We cannot accept a study without validation. One model is not enough to say that Bangladesh is at risk of a mega earthquake," he said.

The Bengal Basin is a living model of an active and complex geological entity, consisting of dynamic depositional complex, heterogenous and multidimensional tectonic deformational settings from three tectonic plates, he said.

It should be mentioned that the 1918 Sreemangal earthquake is of the highest-ever magnitude (7.5) in the country. Since then, no seismogenic structure has been found to cause great earthquakes in Bangladesh.

Dr Badrul Imam, honorary professor of geology at Dhaka University; and Dr Zillur Rahman, dean of DU's Faculty of Earth and Environmental Sciences, also spoke at the seminar.