POBNEWS24, Dhaka, Jan 8, 2025 : Earthquakes have been felt in the country twice in the first seven days of this month (January). Bangladesh has seen many such small-medium earthquakes in the last two years. Experts believe that small earthquakes are a precursor to major earthquakes. Dhaka is among the 20 most vulnerable cities in the world to earthquakes. However, no government has taken any measures to reduce the damage caused by this natural disaster.
Experts fear widespread damage if a major earthquake hits earthquake-prone Bangladesh. Over the past three months, more than 50 earthquakes of both mild and severe magnitude have occurred around Bangladesh. Over the past 15 years, there have been more than 150 small and large earthquakes, which is alarming.
According to experts, these mild earthquakes indicate that a major earthquake may strike in the future. Bangladesh is at risk due to its geographical location. If a major earthquake occurs in the country, Sylhet, Rangpur, Mymensingh and Chittagong may suffer more damage than Dhaka city.
A magnitude 7.1 earthquake struck Tibet on the morning of January 7, killing more than 100 people. The quake was also felt in parts of Bangladesh, Nepal and India at the same time. Earthquakes are common in the region, as it lies on a major geological fault line.
No major earthquake in 75 years, but one expected soon
According to the US Geological Survey, Bangladesh is located in an active earthquake zone. According to the Disaster Risk Index, Dhaka is among the 20 most vulnerable cities worldwide to earthquakes. Small tremors in recent years indicate the country’s vulnerability to more powerful earthquakes.
Historically, Bangladesh has been hit by five earthquakes measuring more than 7 on the Richter scale between 1869 and 1930. The 1885 earthquake and the 1918 Srimangal earthquake were both centered in Bangladesh and caused significant damage. The region has not had a major earthquake for about 75 years, so the risk of a major earthquake occurring soon is high.
Bangladesh at high risk of small-medium earthquakes
Bangladesh was shaken by a 6.7 magnitude earthquake on January 4, 2016. Six people died in panic. Experts claim that the India and Myanmar tectonic plates that pass through Bangladesh have not had a major earthquake in the last hundred years. Therefore, this plate has accumulated a lot of energy. It is likely to appear at any moment through an earthquake of 8 to 9 magnitude. If an earthquake of such magnitude occurs, Dhaka will not be able to handle the shock. Hundreds of thousands of people may die.
Bandarban was the epicenter of the earthquake on April 20, 2024. At that time, an earthquake measuring 4.1 on the Richter scale shook the city.
Earlier, on December 2, 2023, the epicenter of the earthquake was in Rajshahi. At that time, the magnitude was 5.5 on the Richter scale.
Three earthquakes struck the country in September 2023. Of these, an earthquake was felt in various parts of the country, including Dhaka, on September 17. Its magnitude was 4.2 on the Richter scale. Its epicenter was in Tangail, 59 kilometers northwest of Dhaka.
Earlier, an earthquake was felt in the Sylhet region on September 11. Its epicenter was the India-Myanmar border. In addition, another earthquake was felt on September 9. Its epicenter was the Cachar area of Assam, India.
Two earthquakes were felt in Bangladesh in August 2023. One of them was felt on August 29. Its epicenter was Sylhet. Earlier, another earthquake was felt on August 14. Its epicenter was in the Kanaighat area of Sylhet, on the Bangladesh-India border. The two earthquakes in August were located on the Dawki Fault.
On June 5, 2023, a 3.9 magnitude earthquake struck the Bay of Bengal. Indian media outlet Live Mint reported that a 3.9 magnitude earthquake struck the Bay of Bengal this morning. The epicenter of the earthquake was at the bottom of the Bay of Bengal near Myanmar. The depth of the earthquake, which struck at around 8:15 am Bangladesh time, was 10 kilometers.
A joint study by BUET and the government shows that 72,000 buildings in Dhaka would collapse in a 7.5 magnitude earthquake, requiring 70 million tons of concrete piles.
Tectonic Plates and Earthquakes
According to Banglapedia, the geological theory of plate tectonics states that the Earth’s crust is composed of seven large and several smaller moving solid plates that float on a lower, moving, hot mantle. The movement and interaction of the plates is believed to be the controller of significant geological events such as earthquakes, volcanic eruptions, and mountain formation.
How Tectonic Plates Trigger Earthquakes There
are three types of plate boundaries known as convergent boundaries, divergent boundaries, and transform faults. Transform faults are when two plates pass each other, it is called a transform fault. Earthquakes occur when three types of plate movements occur.
Most of the Bengal Basin lies in Bangladesh. It was formed as a result of the collision between the Indian plate and the Asian plate. Before the Cretaceous period (125 million years ago), the Indian plate, including a part of Bangladesh (the greater Rangpur-Dinajpur region), joined with Antarctica, Africa, Australia and South America to form a large continent called Gondwanaland. The rest of Bangladesh did not exist at that time. Then, due to the rifting of Gondwanaland, the northward movement of the Indian plate and its final collision with the Asian plate led to the formation of the Himalayan Mountains and the deltaic plains of Bangladesh.
The periodic collision between the Indian Plate and the Asian Plate first occurred during the early rise of the Himalayas in the Eocene (50 to 55 million years ago). By the Late Eocene (35 to 40 million years ago), the last traces of the Tethys Ocean between the Indian Plate and the Asian Plate probably disappeared. It was during this time that the direction of convergence of the Indian Plate changed from north to northeast, with increasing collision with Southeast Asia.
From the Oligocene (350 million years ago) onwards, plate collisions continued, and as the waters of the vast rivers filled the original Bengal Basin to the south, the sediments of the uplifted Himalayas began to descend. From the post-Miocene (250 million years ago onwards), rapid subsidence of the basin and rapid uplift of the Himalayas led to the formation of vast deltas alongside the massive sedimentary basins.
The process of formation of this large delta called the Ganges-Brahmaputra delta is still ongoing. Meanwhile, the subduction of the Indian plate under the Asian plate has created a junction zone in the northern part of the Himalayas. And in the east, the Indo-Burma mountain range is marked as the eastern plate collision zone. The collision of the Indian plate with the Asian plate continues to this day. Occasionally, earthquakes in the adjacent areas of the plates prove this.
Three active tectonic plates
Mehedi Ahmed Ansari, a professor at the Department of Civil Engineering at Bangladesh University of Engineering and Technology (BUET), told Jago News, “Three tectonic plates have passed around Bangladesh. Their junction is around the border. For example, the Himalayas to our north lie on the Eurasian plate. We are located on the Indo-Australian plate. And to our east is the Myanmar micro plate. All these three plates are connected and active. The plates have movement. They move five centimeters or 50 millimeters every year. That means, every year we are moving five centimeters in the northeast. Similarly, the entire world is moving.”
Professor Mehedi Ahmed Ansari said, “The government has purchased equipment for the fire service and civil defense. It won’t be enough to just provide equipment. Because if the buildings are not repaired, people will die if the buildings collapse. In addition, unplanned gas and electricity lines in Dhaka city have increased the risk of earthquake damage several times.”
Most of the buildings in Dhaka city are at risk,
Director (Operations and Maintenance) of the Fire Service and Civil Defense Department, Lt. Col. Mohammad Tajul Islam Chowdhury told Jago News, “First of all, earthquake awareness is important. Most of the buildings in Dhaka city are at risk. For this, the buildings need to be earthquake-proofed or strengthened. It is necessary to collect dry food, water and first aid supplies as a precaution to keep yourself safe during an earthquake.”
If a magnitude 7 earthquake occurs in the vicinity, there is a risk of extensive damage,
said Dr. Md. Zillur Rahman, Dean of the Faculty of Earth and Environmental Sciences and Professor of the Department of Disaster Science and Climate Resilience, Dhaka University, to Jago News, “Recently, Bangladesh has also been shaken by two earthquakes. These are earthquake-prone areas because they are plate boundaries. There are many such earthquakes every day along the plate boundaries, which are small earthquakes, but sometimes there are also large earthquakes. If a magnitude 7 earthquake occurs in the border area, Bangladesh will have to face extensive damage. There will be damage especially in Mymensingh, Rangpur, Sylhet, Chittagong and Dhaka. There will be damage in Dhaka because most of the buildings in Dhaka are vulnerable.”
He said, “Bangladesh is close to the plate boundary, there have been major earthquakes here in the past and there may be more in the future. In terms of risk, Bangladesh is an earthquake-prone country. Buildings in different areas of the country, including Dhaka, are not designed according to that risk. The old buildings are fragile and the new buildings are not built according to the ground parameters. That is why the risk is very high. It is possible to build earthquake-resistant buildings in Bangladesh as well. Developed countries including the United States and Japan have done it.”
Vibration alarming, the weakness of the authorities in complying with building codes is alarming.
Professor of the Department of Urban and Regional Planning at Jahangirnagar University, Executive Director of the Institute of Planning and Development (IPD) and former General Secretary of the Bangladesh Institute of Planners, Adil Muhammad Khan told Jago News, “A large earthquake in the vicinity is alarming for Bangladesh. Some earthquakes have occurred in and around Dhaka for several years. Our demand was that the buildings be built according to the building code. The buildings that are being built should be built in the right place. The weakness of the authorities in complying with the building code is alarming. They have not shown any skill or interest in conducting on-site investigations so far. On the contrary, the trend of building multi-storey buildings by filling low-lying land and wetlands has increased to an epidemic level in the last 10 years.”
He said, “Buildings are being built by filling up wetlands, which violates most laws. In this case, the authorities are silent. After a few years, when the master plan is revised, they say that since it has been done, what can we do without approval… If this trend continues, there will be no need for a major earthquake. If the earthquake originates in Dhaka and the surrounding areas, it will cause a lot of damage if it is 5 or 5.5 magnitude.”
“The government is already yielding to pressure from the real estate community to legalize the haphazard and unlicensed multi-story risky buildings in Bangladesh. Mega projects are being carried out in places where you would stand in a shelter in case of an earthquake. At the end of the day, we rarely get good news about earthquakes.”
Professor Adil Muhammad Khan, who repeatedly mentioned that the authorities do not perform their main duties on the pretext of lack of manpower, said, “Here, the authorities mean the state. Because the state ministries do not do the right thing. If there is no power to see that someone disobeys the law, then what is the need for the authorities to exist? The state is undergoing many reforms, but so far we have not seen any reforms within the authorities. The authorities have no history of catching those responsible for their lawlessness.”
