From the moment I heard the news about the recent earthquakes in Southern Japan and in Ecuador, I cannot help reminding everyone what will happen to Metro Manila if a 7.2-magnitude earthquake occurs today. Ecuador was rocked by a 7.8-magnitude earthquake and, Japan, with a 7.3. The death toll in Ecuador is currently around 400 and counting, in Japan around 41. But what is more worrisome, based on the JICA study done in 2004, is that the death toll for Metro Manila would be around 30,000 from the earthquake and around 20,000 from the ensuing fire. It is a far cry from Ecuador and Japan. Since publishing the study, what have we done to prepare for a powerful earthquake? Are we ready for it?
When an earthquake devastated Haiti in 2010, Anna Coren of CNN interviewed me on the possible impact of an earthquake with a similar magnitude should it happen in Metro Manila. It was only then that I came across a study done by the Japan International Cooperation Agency in 2004 on “Earthquake Impact Reduction for Metropolitan Manila,” also known as the MMEIRS study. It assessed and quantified the impact and damage that the earthquake will cause. With the West Valley fault approaching its active phases, according to PHIVOLCS, it would be important to look back at the MMEIRS study for guidance.
Urban vulnerability: The first hour
According to the MMEIRS study, based on a 2014 population, around 170,000 residential houses will be heavily damaged or collapsed (13 percent of total buildings), 340,000 will be moderately damaged (26 percent of total buildings) and 10,000 alongside of Manila Bay will be affected by liquefaction in the first hour of impact by a magnitude 7.2 earthquake.
Eleven percent of mid-rise buildings (10-30 stories) and 2 percent of high-rise buildings (30-60 stories) will be severely damaged or collapsed. Twenty-seven percent of mid-rise and 12 percent of high-rise buildings will be moderately damaged.
Eight to 10 percent of hospitals, schools, fire stations, police stations and government offices will be heavily damaged or collapsed. Twenty to 25 percent will be moderately damaged.
A hundred kilometers of telecommunication cable and 30 kilometers of electrical cables will snap. There will be a failure of water supply because the dams and pipes will be severely damaged. A total of nine bridges will also be damaged.
Death tolls in the first hour could reach around 34,000 people and another 20,000 could become casualties in the succeeding hours because of the widespread fire and successive tremors that will occur. One hundred 10 thousand will be immediately injured but this number would most probably increase as post-earthquake scenarios came into play.
In the event of a “Big One,” rescue activities will be limited. As it is, it takes two hours to travel five kilometers on an average day in Metro Manila but with buildings and electrical posts toppled down, bridges damaged, thousands of homes on fire, no water supply and debris, among others, it would take longer for rescuers to reach devastated areas. This is also assuming that our government forces and volunteers are safe and pieces of equipment are intact and operational. According to international assessment, help will come after 72 hours but because of Metro Manila’s urban sprawl and poor urban design, I think we can expect that will take more time.
In order to mitigate the impact of a big earthquake, the architects, planners, engineers, and designers of Palafox Associates and Palafox Architecture Group came up with suggestions that were included in the 145 recommendations submitted to the previous and present Philippine government administrations.
We recommended the government to lead a thorough review of the National Structural Code of the Philippines (NSCP). The Code should be assessed in terms of its applicability for earthquakes with a magnitude 8 or higher. City and provincial engineers should also carry out a routine inspection and structural audit of all buildings, particularly the old ones. They should condemn or demolish such unsafe buildings.
Ultimately, corruption kills. Bureaucracy and red tape in securing building permits do not only pain the developer but are also hazardous to the end-users. Quality is sacrificed to offset the cost paid for corruption.
Professionals in the build environment also have important roles to play in ensuring the safety and stability of structures. Location of earthquake fault lines within the vicinity of the planned area for development must be identified so that structural engineers can make adjustments in the design. Builders and contractors must follow the technical specifications provided by the structural engineer. Using cheap and substandard materials and shortcuts in labor procedures will just hasten the deterioration of a building. Designs should be performance-based.
While each individual is responsible for being prepared in times of disasters, there should also be an integrated approach from both public and private sectors. Our country’s resilience to disasters depends on individual preparation backed by a visionary government that has strong political will.