And what you can do about it
Exclusive by Raïssa Robles
Tens of thousands dead, buildings and homes toppled, a mega-city in ruins. You’ve probably heard and read this description of Metro Manila if it were hit by a 7.2 magnitude earthquake generated by the West Valley Fault.
What you haven’t read are the specifics, which for some reason the mass media have refrained from publishing. Details, such as the fact that much of Loyola Grand Villas in Quezon City could be flattened. Or that the east-most side of the neighboring upscale La Vista Subdivision could crumble.
The Metro Manila Development Authority (MMDA) recently announced it was releasing to every city and town in Metro Manila or the National Capital Region quake risk assessment maps funded by Australia. Interestingly, the maps shown on TV news are not detailed. They merely show the towns and cities, not the barangays.
This article is intended to prod authorities to release “catastrophe maps” of Metro Manila, which could give predictions of the fate facing specific barangays and subdivisions that have the misfortune of being near, or across the West Valley Fault,
It’s based on the 2004 Study for Earthquake Impact Reduction for Metropolitan Manila in the Republic of the Philippines or MMEIRS.
A fault is a fracture on the earth’s surface. According to this website on earthquakes, “stresses in the earth’s outer layer push the sides of the fault together… Eventually enough stress builds up and the rocks slip suddenly, releasing energy in waves that travel through the rock to cause the shaking that we feel during an earthquake.”
Filipino scientists have confirmed that the West Valley Fault is ripe for a slip.
The 2004 MMEIRS study noted:
“Many faults are identified around Metropolitan Manila; the West Valley Fault (WVF) and the East Valley Fault (EVF), which run north to south along the west and east edge of the Marikina Valley, are thought to pose the greatest threat to Metropolitan Manila due to their proximity.”
The graph below from the MMEIRS study shows which Metro subdivisions could be most affected since these are “transected” or cut across by the West Valley Fault:
This article is not meant to scare you, but to help you plan out a disaster mitigation program, working with your barangay officials – you just voted them into office last Monday Oct 28, remember? Your city and town officials, whom you also elected this May.
Here are four things you can do for starters:
1. Find out when your home, office building and school where your children study were built.
I asked that question of Franklyn Santos, an architect from the University of Santo Tomas who had designed and built our home with a team of UST colleagues . He told me that by chance, it was built AFTER the 7.2 magnitude Kobe earthquake of 1995. And it so happened that the structural engineer who was his friend and consultant then was studying and working in Japan when the quake reduced Kobe to rubble.
Franklyn recalled that after Kobe, building contractors in the Philippines started incorporating the lessons of Kobe. He said, though, that enforcement by city and town building officials in NCR of this practice has been spotty.
Buildings and homes constructed before that period can be retrofitted. Ways to strengthen structures are provided at the end of this piece.
2. Nag your LGU (local government unit) to inspect every building, assisted by structural engineers from the private sector.
Merely asking building officials to conduct inspections would not be a good thing since they were supposed to certify these in the first place.
Franklyn also stressed the need to make sure glass used in high rises and schools are quake-proof to avoid slicing up people on the ground.
3. Ask your barangay to dig a deep well for communal use during disasters.
Franklyn also said that if a 7.2 magnitude quake struck, NCR should anticipate that water pipes would be broken and there would be no power and possibly phones for days. The 2004 MMEIRS study actually calculated the extent of the damage:
Franklyn noted that while NCR residents could live without power and phones, water was a necessity. He recalled that some barangays in Quezon City previously dug deep wells as a result of their experience following the Mt Pinatubo eruption and the 1990 earthquake as well as a series of deadly typhoons that interrupted water and power supplies. He wondered what had happened to these deep wells, which he suggested should not be used daily but merely in times of emergency.
4. Compel cities, towns and barangays in Metro Manila to identify safe evacuation sites.
The other day, while wrestling with words to write this, I had a thought – if a very strong earthquake occurs, where could my family run to until the ground stops shaking. I realized there is no open space near my house that is safe from falling power wires or collapsing houses.
I also realized why quake-beleaguered Tokyo has lots of pocket parks – green open spaces with trees only at the fringe. These are for people to stay in during earthquakes.
We don’t have those because our politicians have left city development to commercial real estate developers who place profit first.
The MMEIRS study, funded by Japan International Cooperation Agency (JICA) was completed nearly a decade ago but only its executive summary has been released to the public, and only recently.
I suspect a not-so-noble reason for the non-release of the complete study. Real estate developers and sellers did not want you to know they had sold or were selling land in dangerous zones.
It’s high time we, the people of Metro Manila, had a say in how our metropolis grows.
“Model 08, as the worst case, 170,000 residential houses will collapse, 340,000 residential houses will be partly damaged, 34,000 persons will die, 114,000 persons will be injured. Fire will break out and burn approximately 1,710 hectares and totally 18,000 additional persons will be killed by this secondary disaster. Moreover, infrastructures and lifelines will also be heavily damaged.”
Model 08 refers to the West Valley Fault System slipping and generating a 7.2 magnitude quake.
If such a quake occurs, seven bridges are likely to fall.
“Metropolitan Manila will possibly be separated into four regions by the earthquake impact,” the study said.
1. The western part will be isolated from other parts of Metropolitan Manila by fire and building collapse
2. The northern and southern part will be separated by building collapse and by its geography: “The intersecting area between Mandaluyong and Makati has a high possibility of building collapse; moreover, Pasig River is running through east-west which is naturally disadvantageous in terms of separation.”
3. As for the eastern part, “all road networks running east-west, which are on the fault will be broken due to the movement. Other roads running North-South in fault areas will be difficult to use, due to the high number of building collapse.”
Before I go on, I would like to thank Aldo R. Mayor, chief of the Public Safety Division of the Metro Manila Development Authority (MMDA) who gave me a copy of his power-point presentation entitled “Disaster Risk Reduction Management and Earthquake Preparedness.”
It was Mayor who drove home to me for the first time the urgent need for all NCR residents to prepare.
And for residents to nag their barangay officials, city and municipal governments, the MMDA and the national government to do likewise. Because the costs of an earthquake and lack of preparation will be huge since NCR is the heart of the nation’s economy, politics and business.
I have debated with myself for months whether I should publish this.
The recent 7.2 magnitude earthquake in Bohol nudged me to do so. It is the same magnitude that the MMEIRS study labelled as “the worst case scenario” for this metropolis of 11.8 million people.
The data below, which I obtained from Aldo Mayor’s power-point presentation, gives some answers to the following questions:
1. Which areas in NCR are likely to be hit hard?
2. How can we check ourselves whether our homes and offices can withstand a 7.2 magnitude quake?
3. What can we do to prepare?
4. What should we demand of the barangay where we live and work, the city governments and the national government, including the MMDA, to prepare?
You can read at the end of this piece the MMEIRS executive summary.
The MMEIRS study examined all the known earthquakes that have shaken NCR since 1599. Drawing from this historical data, it then selected the three most damaging “scenario earthquakes.” These are:
Model 08 (West Valley Fault)- the worse case scenario
Model 13 (Manila Trench)
Model 18 (1863 Manila Bay)
This is the West Valley Fault scenario:
It noted the following secondary consequences of an earthquake:
MMDA’s Aldo Mayor provided the following examples:
The MMEIRS study then estimated which areas in NCR are likely to be hit hardest by these consequences [Note – the roman numerals refer to the quake magnitude]:
Here is an explanation of the quake magnitude:
Here is the possible building damage in NCR cities and towns under the worst case scenario. Quezon City, Manila, Pasig and Marikina in that order could bear the brunt.
In terms of deaths, it’s Manila, Quezon City, Pasig, Marikina, Makati, Taguig and Muntinlupa, in that order:
Aldo Mayor’s slides show further which barangays in five cities of NCR could have the most or least collapsed and damaged buildings and homes:
In other words, the cooler the color, the less damage structures will likely sustain. The colors range from gray, blue, green, yellow, brown, red. In red areas, from 500 to 3,000 structures could collapse in a 7.2 magnitude quake.
Here’s Makati City:
South Caloocan (1st District):
South Caloocan (2nd District):
Sorry. Those are the only areas included in Mayor’s power-point presentation. If you live somewhere else, I suggest you ask MMDA or Phivolcs to release the data about your area. Ask your mayors, too, since they will soon get the latest risk assessment maps.
I wonder what Marikina would look like.
This is how the entire NCR could look in terms of building damage:
As for the outbreak of fire that follows an earthquake, here are the likely areas to be hit hardest in NCR:
The map below shows the areas where liquefaction could occur:
What we can do to prepare for a big earthquake
MMDA’s Aldo Mayor suggested the following:
Ever noticed these orange and blue steel containers parked in the middle of Edsa and other major roads?
These actually contain tools to rescue quake victims and lime to sprinkle on the dead:
But just a thought. Wouldn’t these containers be useless if the overpass or MRT were to collapse on them?
And how can a mere dozen such containers help a metropolis of 11.8 million people?
The answer lies in our LGUs and barangays, which need to come up with disaster mitigation plans and have equipment and first aid available for such a catastrophe.
The MMDA has been quietly training LGU and barangay officials for disaster but it seems some LGUs are NOT interested:
Here are links to affordable tips to quake-proof homes:
Here is the executive summary of the MMEIRS study. It details on page 5 all the earthquakes that have struck or affected Metro Manila since 1599: