On the 21st of August, mild earthquake tremors in different parts of Karachi serve as a wake-up call to all urban planners, real estate developers and building control officials in the city. According to the Pakistan Meteorological Department, a magnitude 3.1 earthquake was recorded on the Richter scale in the metropolis at late morning, of which epicenter was 72 kilometers northeast of Karachi and the depth was 15 kilometers.
Although, no deterioration so far has been reported, but these jolts compel everyone to enquire the safety and sustainability of vertical developments in Karachi.
Tremors are a normal occurrence in many parts of the world. They are sudden and dangerously powerful which makes them serious threat to communities nationwide and bring earthquake at the top of the list of disaster control management studies globally. However, reducing the risk of disaster caused by earthquake in urban areas is largely a development issue, therefore, needs to be addressed within context of a wider urban development network.
Why Karachi is Vulnerable to Earthquake?
Karachi lies very close to a major fault line, where the Indian tectonic plate meets Arabian tectonic plate. According to seismologists up to 95% of all recorded earthquake have taken place along fault lines where two or more tectonic plates meet. Moreover Makran-Sindh coastal areas are prone to tsunami as well. Besides, studies and researches after deadly earthquake of 2005 shows that Karachi is more vulnerable to earthquakes than what is considered while planning and designing the buildings.
Earthquakes possibly pose the greatest threat of widespread destruction in a city brimming with permanent steel, glass, and concrete structures. As if these structures fracture or collapse, no emergency plan can protect the people from harm. It has been diagnosed in various geological researches that the existing and proposed tall buildings here do not have sufficient capacity to withstand higher seismic risk.
Yet for a megacity like Karachi the one and only way to survive in earthquake disaster is by taking careful considerations while planning and designing building structures and high rise developments.
Violations in High rise Construction
Reducing disaster risk contributes to strengthening urban resilience and sustainable urban development. Therefore it had been recommended very earlier that buildings, including skyscrapers, should be constructed in a manner that allow them to withstand shocks of earthquake. But can skyscrapers in Pakistan withstand any major earthquake?
It is very unfortunate that building by-laws and environmental codes are routinely violated whenever and wherever a high-rise structure or housing society is developed. Various building control authorities in Pakistan issue Non Objection Certificate by skipping these violations. There are a number of horrendous examples of houses and apartments built without a NOC or owners and renters are allowed to move into an apartment building before a completion certificate is issued. Tragic memories of Margalla Tower in F-10 Islamabad are still afresh. The inhabitants had moved in the structure without receiving a completion certificate, never imagining that 78 of them would die in the 2005 earthquake.
Earthquake Resilient Structures
Human safety in high rise living becomes even more urgent with the Prime Minister Imran Khan’ vision for future cities. In his tweet he states “Pakistani cities have been expanding horizontally for a long time now and it is now time for vertical cities”. It put great responsibility on high rise developers to prioritize Earthquake-resistant structures while constructing something vertically or even horizontally.
Earthquake-resistant structures are buildings designed to prevent total collapse, preserve life, and minimize damage in case of an earthquake or tremor. Following the parameters of earthquake resistance or resiliency, buildings and skyscrapers are constructed in a manner that allow them to withstand shocks measuring up to 7.0 on the Richter scale. However, Japan is much ahead among the rest where buildings are now being constructed which can absorb up to 8 magnitude shocks.
All buildings in Karachi inclusive of high rise are, therefore, designed in that way because without fully observing international safety standards, vertical buildings can be a disaster in the making.