The earthquake is not imminent but inevitable as sections of the earth's crust press against one another, according to the study published in the journal Nature Geoscience on Monday.

No estimate on when such a quake may occur is possible without additional research, the study's lead author Michael Steckler, a geophysicist at Columbia University in New York, told the Thomson Reuters Foundation.

Some 140 million people live within 62 miles (100 km) of the potential epicentre in eastern India and in Bangladesh, the world's most densely populated country and among the poorest, the study said.

In Bangladesh, shoddy, unregulated building construction abounds, and heavy industries, power plants and structures at natural gas sites would likely be destroyed, the study's authors said.

Mud that has accumulated some 12 miles (19 km) deep in the delta of the Ganges and Brahmaputra rivers could shake "like gelatin, and liquefy in many places, sucking in buildings, roads and people," said co-author Syed Humayun Akhter, a geologist at Dhaka University, in a statement.

The area at risk measures some 24,000 square miles (62,000 square km), the study said.

People rush out to the street in Dhaka after a quake in May, 2015.

The damage could be so severe as to render Dhaka, Bangladesh's capital, unliveable, Akhter said.

The area at risk lies along the same fault lines in the earth's crust where a 2004 earthquake and tsunami in the Indian Ocean killed some 230,000 people, the researchers said.

The researchers used computer models to analyze ten years of data showing that the earth's plates under eastern Bangladesh and eastern India have been creeping northeast into neighbouring Myanmar, causing instability.