Pakistan sits on top of three tectonic plates that are very slowly colliding into one another. The eastern half of the country lies on the edge of the Indian plate while the western half lies on the Eurasian plate. The southwestern part (at Arabian Sea) is bordered by the edge of the Arabian plate. The collision of these plates has a history expanding over 30-40 million years. The Indian plate has slowly been crashing into the Eurasian plate around three centimeters every year (Himalayas mountain range is a product of this collision process). This tectonic setting has resulted in a number of seismically active faults in areas close to the boundary of the two plates. These faults are capable of producing moderate- to large-magnitude earthquakes.
The 2005 Kashmir earthquake was part of this series of quakes originating at the fault system along the India-Eurasia plate boundary. It was a magnitude-7.6 event with a depth of 15 km, underneath a point located 19 km northeast of Muzaffarabad. The damage caused by the earthquake had led to the death of at least 85,000 people. More than 100,000 were injured and three million homes destroyed. Massive landslides triggered as a result of the earthquake had buried entire towns in northern areas.
Disasters of such a huge magnitude generally lead to important social reforms in terms of legislations and action plans for enforcement of construction bylaws and development of emergency relief and preparedness infrastructure. Over the last couple of centuries, all major developments pertaining to human safety and wellbeing in developed countries have followed in the wake of disasters of one kind or the other.
However, Pakistan still hasn’t done enough to prepare itself for future earthquakes, despite being hit so severely in October 2005.
Read more: The Science of Earthquakes
More than 2.5 million people are estimated to have died in earthquake-related accidents in the last 100 years. Most of these deaths were caused by collapse of built structures e.g. buildings and bridges. Therefore, efforts for reducing the loss of lives in earthquakes really boil down to introduction of better technology in the construction sector.
Civil engineers tell us that a building can only be as strong as its weakest corner. During an earthquake, the shaking ground causes inertial forces to develop in buildings. Buildings designed well should be able to resist these forces by efficiently absorbing the shaking energy. However, in an improper engineering design, much of the attention (in terms of strengthening) is paid to individual components of buildings, leaving corners as pockets of weakness. Add to this poor construction practices and use of substandard materials and you have a perfectly vulnerable building.
By creating sophisticated 3D computer models of buildings and subjecting them to earthquakes recorded so far, experts can simulate the level of expected damage. This modelling tells us that it’s neither the sturdiest nor the most expensive buildings that are more likely to survive an earthquake. Those built smartly with an engineering design that enables them to efficiently absorb the shaking energy are most likely to survive earthquakes.
So should we blame engineers and experts for such a catastrophic failure of our infrastructural facilities? Maybe not, as they are already having a hard time convincing the public about the risks. But their efforts require complementary measures to be successful. How can building owners perceive the potential risk without any prior background information on the subject? Why should real-estate developers pay the extra cost?
I can relate my own experience about this during the relief and rehabilitation phase following the 2005 earthquake. It was extremely hard for me to convince residents in affected areas that they should not simply rebuild their houses as unreinforced stone-masonry structures.
After the 2005 disaster, the Government of Pakistan’s Ministry of Housing and Works (MOHW) decided to revise and update the Building Code of Pakistan, to incorporate various seismic safety provisions in the design of buildings. This task was assigned to the National Engineering Services Pakistan (NESPAK), which conducted a seismic hazard analysis and developed a seismic zonation map. The country was divided into five seismic zones and the safety provisions for structures in highly prone areas were enforced. This map was included in the 2007 version of the building code.
In the map, areas with high seismic threat are shown in red and orange, while low seismic hazard zones are shown in dark and light blue colors. The areas in light green are at a moderate-level threat.
However, this map only tells half of the story. We need to overlay on it the situation of population density, infrastructural quality, capacity of disaster mitigation authorities and rescue agencies to get at the complete picture.
Take the case of Karachi for example. The city is located relatively far from active faults and, therefore, it is considered to be at low- to moderate-level threat from earthquakes. However, the high population density and presence of various high-rise buildings increases means that the risk associated with earthquakes is far from low- to moderate-levels.
So what will it take to defeat earthquakes in Pakistan? We already have examples of countries that have significantly reduced their vulnerability, and associated social and economic loss, to earthquakes. Recent research and technological advancements have resulted in many new, more reliable, and safer building systems in countries like USA, Japan, and New Zealand.
To ensure a sound disaster resilience, preparedness, and mitigation mechanism, we need to fight on multiple fronts. In what follows, I have briefly discussed four important components of such a mechanism that can enable us to reduce earthquake risk in Pakistan.
- Building Code: Building codes are a set of rules and regulations specifying the minimum safety, health, and energy standards for the design, construction, and maintenance of buildings. Although various seismic provisions were incorporated into the Building Code of Pakistan after the 2005 earthquake, the revision and upgrade of the Code needs to be a continuous process. This should be done in view of various international codes and guidelines; new and more detailed studies assessing the seismic hazard in highly-vulnerable areas; detailed studies of soil properties in all regions of the country; and guidelines for the use of the latest seismic analysis and design procedures for buildings.
- Disaster Preparedness, Response, and Mitigation: This is perhaps the most important front to focus on. A technically equipped, well-managed, integrated and transparent action plan driven by a sincere desire and motivation to achieve earthquake resilience is the key to accomplish this goal. From the topmost level to the local-community level, there is a lot to learn from the vision and targets set by various international emergency management agencies across the globe.
- Role of Private Sector and Civil Society: The civil society needs to play its role in creating an overall awareness and suitable environment for conducting capacity building programs in less-developed communities. Similarly, real-estate developers and owners should realize that by just spending 10-15 percent more on structural design of their buildings, they can ensure the safety of the residents.</
- Role of Engineers and Academia: We often hear about industry-academia gap as a potential reason for slow adoption of latest technologies in various sector. No other sector needs to reduce this gap more than the construction sector If we compare theory and practice in the construction sector, it seems as if the industry and the academia are operating on two different islands. Research, without applicability, is an incomplete enterprise. The construction industry is still following ill-informed procedures based on cookbook-type prescriptive recipes, with little or no insight into how buildings will cope with disasters like earthquakes. Industry-academia collaboration will go a long way in making available to the public the basic information about preemptive measures, safety actions, and emergency relief.
Finally, we need to keep asking ourselves the big question: how long will it take for our efforts and contributions to result in a strong realization of earthquake risk among the public? A realization that if not built properly the buildings that are outcomes of their lifelong economic struggle can become the token of their deaths. Without proper awareness and safety considerations, we may be living in our own tombs.
We can’t tell when will the next big one hit us. But if we continue to evade measures needed for preparedness and resilience, we can be sure that not many of us will see it coming.
This is the second article in a two-part series to mark the 12th anniversary of October 2005 earthquake.
Fawad Ahmed Najam has a PhD in Structural Engineering from the Asian Institute of Technology (AIT) in Bangkok, Thailand. He currently teaches Civil and Structural Engineering at the National University of Sciences and Technology (NUST) in Islamabad.