Marikina Valley Fault System
The Marikina Valley Fault System is a dominantly dextral strike-slip fault system which extends from Dingalan, Aurora in the north and runs through the cities of Quezon, Marikina, Pasig, Makati, Parañaque, Taguig and the provinces of Laguna and Cavite.
Threat to Manila
The fault possesses a threat of a large scale earthquake with a magnitude of 7 or higher  within the Manila Metropolitan Area with death toll predicted to be as high as 35,000 and some 120,000 or higher injured and more than three million needed to be evacuated.
The fault contains two major segments, known as West Marikina Valley Fault (WMVF) and East Marikina Valley Fault (EMVF).
The west segment, known as the West Marikina Valley Fault (WMVF) is one of the two major fault segments of the Valley Fault System which runs through the cities of Marikina, Pasig and Muntinlupa and moves in a dominantly dextral strike-slip motion. The West Fault is capable of producing large scale earthquakes on its active phases with a magnitude of 7 or higher.
- Rimando, Rolly E.; Knuepfer, Peter L.K. (2004). "Neotectonics of the Marikina Valley fault system (MVFS) and tectonic framework of structures in northern and central Luzon, Philippines". Tectonophysics 415 (1-4). Elsevier. pp. 17–38.
- Nelson, Alan R.; Personius, Stephen F.; Rimando, Rolly E.; Punongbayan, Raymundo S.; Tungol, Norman; Mirabueno, Hannah; Rasdas, Ariel (2000). "Multiple Large Earthquakes in the Past 1500 Years on a Fault in Metropolitan Manila, the Philippines". Bulletin of the Seismological Society of America 90 (1). pp. 73–85.
- Ubac, Michael (20 June 2009). "UN to Metro Manila: Ready for Big One?". Manila, Philippines: Inquirer. Retrieved 2010-01-30.
Is Metro Manila prepared for the Big One?
- "Big earthquake in Marikina Valley fault line?". Pinoymoneytalk.com. Retrieved 2010-01-30.
The United Nations is advising the Philippines to be ready for an upcoming big earthquake. A quake with a magnitude of 7 or higher on the Richter scale is sure to hit Metro Manila, they say, but the bigger question is when exactly this will happen.
- "‘Big One’ Is Possible But Metro Is Unprepared". Quezon City, Philippines: Bulatlat. 14 August 2004. Retrieved 2010-02-03.
If a major earthquake were to hit Metro Manila today, the devastation would be so big even disaster response authorities cannot simply cope with it. And it even looks like disaster preparedness occupies a low priority among officials down to the municipal level.