Earthquake preparedness in Dhaka
There are many cities around the world with many tall buildings and skyscrapers. Few, however, are in as much risk as Dhaka city. The geological location of the city, unplanned buildings, and dense population make Dhaka a ticking time-bomb. There are many who would say that Dhaka is only here temporarily. Science says that a massive earthquake in this region is inevitable. It is not a matter of ‘if’ but a matter of ‘when’. An earthquake on Richter scale 8.5-9.0 would destroy Dhaka city causing it to eventually become an abandoned area.
It will not come as a surprise to anyone that the buildings of Dhaka are not equipped to deal with a large scale earthquake. We spoke to Architect Md Mahbubul Huq (Director, Bangladesh Atomic Energy Commission (retired)) for more insight. According to him, we have not had any massive scale earthquake in recent generations which makes it hard to say what will happen when something like that does take place. He added, “Many builders claim that their buildings can withstand a large scale earthquake but until these claims are tested, there is no way to be sure. There are building codes in place but nobody to ascertain whether they are followed. It is questionable whether many buildings are even suited for occupancy, let alone to withstand a massive earthquake. And it is not only buildings that we should be concerned about. There are utility structures related to water, electricity, and gas that would fail in the event of a massive earthquake. This would also cause severe problems as gas tanks can catch fire and people can lose access to drinking water.”
A large scale earthquake would require a massive emergency response from the government. According to disaster management expert Dr Md Nadiruzzaman (Assistant Professor, Independent University Bangladesh) we can get an idea of what would happen if we look at the way fires are dealt with in Dhaka. From the lack of safety precautions in place to response time, there is much room for improvement, particularly in slum areas. A large earthquake will not only cause structural damage to buildings but will cause fires as well. The only thing that can be done is to make sure that all buildings have proper escape routes. Regular fire drills and awareness campaigns are a must. Our authorities have been slow to rise to the challenge. “In our country, nobody does anything until it is too late. Therefore, pro-active measures need to be taken so that we can be best prepared for any kind of disaster,” Dr Nadiruzzaman concludes.
Rising skylines are a common feature in metropolises around the world. Dhaka is one of the few that are particularly in danger. The answer lies beneath the surface on which Dhaka has been built. Even if we have buildings up to code and an efficient emergency response system, we would still be in danger. This is because of the geological location of Bangladesh. According to Dr. Syed Humayun Akhtar (Professor of Geology at Dhaka University), Bangladesh sits at the converging point of three tectonic plates - Indian plate, Tibetan sub-plate, and Burmese sub-plate. The converging place of the Indian plate and the Burmese plate goes through Bangladesh. The Indian plate is moving beneath the Burmese plate in a process called ‘subduction’. This process, along with the Dauki fault puts Bangladesh at great risk of a high-level earthquake. Dhaka itself is close to all possible starting points of earthquakes.
“There are two major seismic belts in the world. Bangladesh is in the Alpide belt while places like Japan, Alaska, California, and Chile are in the circum-Pacific belt. The difference between these two belts is that in the Alpide belt earthquakes occur less frequently but at higher scales while in the circum-Pacific belt they occur more frequently at lower scales. This is why countries like Japan are so well adapted to earthquakes, explains Dr Akhtar. Because these are a regular occurrence, the Japanese government and its people have adapted to deal with them. Fewer earthquakes occur in the Alpide belt in which Bangladesh lies, but that does not bode well for us because the larger the interval between earthquakes, the deadlier their effect. The last major earthquake in our subduction zone was 800-1000 years ago. This has caused a great amount of energy to accumulate. When that energy finally releases, the effect will be deadly. Age-dating shows that the recurrence period of earthquakes in this subduction zone is 400-900 years. Which means we may be close to a colossal earthquake event.”
We live in an earthquake-prone region where massive earthquakes occur over large timescales. Our current generation has not witnessed any such earthquake, neither has the previous or the one before that. What usually happens when natural disasters take place over long periods of time is that people become complacent. We have not seen any massive earthquake for many generations, yet we stand at the brink of one. We are not prepared but we need to be. It is hard to predict what will happen because nothing like this will have happened before. 800-1000 years ago there were no tall buildings and the crowded Dhaka we know today did not exist back then. The level of destruction that will take place is hard to fathom. It might happen today or it might happen 50 years from now but it will eventually happen and we are like sitting ducks unless we act now.