Scientists have revealed that as many as 140 million lives could be at risk if a massive earthquake strikes Bangladesh.

A new study shows that there is pressure building along a fault line under the country, which is the world’s most densely populated nation. The paper was published in Nature Geoscience on Monday, and reveals that two major tectonic plates are locked at a juncture in the region, according to findings.

Bangladesh Earthquake
Image source: Wikimedia Commons

Researchers concerned about potential earthquake

This means that stress is building and could be released in the form of a devastating earthquake. Scientists used GPS data collected since 2003, and say that tectonic plates are converging at a rate of 13-17mm per year “on an active, shallowly dipping and locked megathrust fault.”

Deep below the surface of the Earth, one tectonic plate is moving beneath another. However the two plates are caught on each other in the upper layers of the fault. Layers of sediment over 20 meters thick cover both of the plates.

The release of the stress could lead to an 8.2-9.0 magnitude earthquake striking Bangladesh.

“Some of us have long suspected this hazard, but we didn’t have the data and a model,” said study co-author Michael Steckler, a geophysicist at the Lamont-Doherty Earth Observatory at Columbia University in New York. “Now we have the data and a model, and we can estimate the size.”

Safety situation worst in Dhaka region

According to Steckler and his team there are 140 million people that live within 100km of the fault. They would be at risk if an earthquake did occur. However Steckler said that it is impossible to predict when a quake might happen.

“We don’t know if it’s tomorrow or if it’s not going to be for another 500 years,” he said. “We don’t know how long it will take to build up steam, because we don’t know how long it was since the last one. But we can definitely see it building.”

Steckler believes that the 17 million people who live in the Dhaka region of the country are most at risk. It is a low-lying area famed for its poor construction standards, which make it a high-risk area for building collapses in the event of an earthquake.

Overcrowding would make rescue missions difficult

It is also thought that overcrowding in the city of Dhaka could make rescue efforts more difficult.

“Right now, the streets are clogged with traffic such that it’s impossible to drive around Dhaka on a normal day,” he told Live Science. “If you fill the streets with debris, it’s really going to be impossible to get supplies and rescue equipment and things like that around.”

“Bangladesh is overpopulated everywhere,” said study co-author Syed Humayun Akhter, a geologist at Dhaka University. “All the natural gas fields, heavy industries and electric power plants are located close to potential earthquakes, and they are likely to be destroyed. In Dhaka, the catastrophic picture will be beyond our imagination, and could even lead to abandonment of the city.”

 Further study needed to properly assess risks

Researchers are now working on a more detailed map of the fault, and studying historical tsunami data to work out how frequently these megathrust earthquakes have occurred in the past. The area in question is part of the same fault line which led to the 2004 Indian Ocean earthquake and tsunami, a disaster which led to the loss of 230,000 lives in 14 countries.

In addition the scientists will use seismometers in Myanmar to study the sunduction zone. James Ni, a seismologist at New Mexico State University, said such a powerful earthquake could turn areas of India “into ruins”.

“We don’t have a good idea of its geometry, we don’t know how far it goes down. We need more data,” he said.

A 2011 earthquake triggered the tsunami which rocketed Japan and wiped out the Fukushima nuclear power plant. The danger of these powerful tremors should not be underestimated, but it must be said that they cannot be prevented.

Authorities can only hope to make sufficient preparations to minimize any damage when the earthquake hits. In Bangladesh the lack of a coherent plan means that millions of lives are in greater danger.

While scientists cannot change the reality of life on the ground, they can provide detailed information in the hope of convincing governments to make earthquake contingency plans a priority. The earthquake may not strike within out lifetime, but that does not mean that we should not be prepared if it does happen.

The risk of losing 140 million lives should be motivation enough to make safety plans.