The Marikina Valley Fault System, also known as the Valley Fault System (VFS), is a dominantly right-lateral strike-slip fault system in

Luzon Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...

, Philippines. It extends from Doña Remedios Trinidad,

Bulacan Bulacan, officially the Province of Bulacan ( tl, Lalawigan ng Bulacan), is a province in the Philippines located in the Central Luzon region. Its capital is the city of Malolos. Bulacan was established on August 15, 1578, and part of the Me ...

in the north and runs through the

provinces A province is almost always an administrative division within a country or state. The term derives from the ancient Roman '' provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions ou ...

Rizal Rizal, officially the Province of Rizal ( fil, Lalawigan ng Rizal), is a province in the Philippines located in the Calabarzon region in Luzon. Its capital is the city of Antipolo. It is about east of Manila. The province is named after Jos� ...

, and the

Metro Manila Metropolitan Manila (often shortened as Metro Manila; fil, Kalakhang Maynila), officially the National Capital Region (NCR; fil, link=no, Pambansang Punong Rehiyon), is the capital region, seat of government and one of three List of metrop ...

cities A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be def ...

Quezon Quezon, officially the Province of Quezon ( tl, Lalawigan ng Quezon), is a province in the Philippines located in the Calabarzon region on Luzon. Kalilayan was the first known name of the province. It was later renamed Tayabas. In honor of the ...

Marikina Marikina (), officially the City of Marikina ( fil, Lungsod ng Marikina), is a 1st class highly urbanized city in the National Capital Region of the Philippines. According to the 2020 census, it has a population of 456,159 people. It is locate ...

Pasig Pasig, officially the City of Pasig ( fil, Lungsod ng Pasig), is a 1st class highly urbanized city in the National Capital Region of the Philippines. According to the 2020 census, it has a population of 803,159 people. It is located along the ...

Makati Makati ( ), officially the City of Makati ( fil, Lungsod ng Makati), is a 1st class highly urbanized city in the National Capital Region of the Philippines. Makati is the financial center of the Philippines; it has the highest concentration ...

Taguig Taguig (), officially the City of Taguig ( fil, Lungsod ng Taguig), is a 1st class highly urbanized city in Metro Manila, Philippines. According to the 2020 census, it has a population of 886,722 people. Located in the northwestern shores of ...

and

Muntinlupa Muntinlupa, officially the City of Muntinlupa ( fil, Lungsod ng Muntinlupa), is a 1st class Cities of the Philippines#Legal classification, highly urbanized city in the Metro Manila, National Capital Region of the Philippines. According to the ...

, and the provinces of

Cavite Cavite, officially the Province of Cavite ( tl, Lalawigan ng Kabite; Chavacano: ''Provincia de Cavite''), is a province in the Philippines located in the Calabarzon region in Luzon. Located on the southern shores of Manila Bay and southw ...

and Laguna that ends in

Canlubang Canlubang is a major industrial zone located in the province of Laguna, southwest of Metro Manila in the Philippines. It was once a hacienda during the Spanish colonial period. Canlubang straddles two component cities of Laguna: Cabuyao, Calamba ...

Fault segments

Relief Map of Metro Manila and nearby provinces showing the West and East Valley Fault Line

The fault contains two major segments, known as West Valley Fault (WVF) and East Valley Fault (EVF). ;West Valley Fault The west segment, known as the ''West Valley Fault (WVF)'', is one of the two major fault segments of the Valley Fault System which runs through

to the cities of

Quezon City Quezon City (, ; fil, Lungsod Quezon ), also known as the City of Quezon and Q.C. (read in Filipino as Kyusi), is the List of cities in the Philippines, most populous city in the Philippines. According to the 2020 census, it has a populatio ...

and

and moves in a dominantly

dextral Sinistral and dextral, in some scientific fields, are the two types of chirality (" handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use differe ...

strike-slip motion. The West Valley Fault segment traverses from Doña Remedios Trinidad to Calamba with a length of . The West Fault is capable of producing large scale

earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fro ...

on its active phases with a

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

of 7 or higher. ;East Valley Fault The eastern segment, known as ''East Valley Fault (EVF)'', moves in an oblique

motion. It extends to about from Rodriguez to San Mateo in the province of

Threat

] Based on kinematic block models that utilize GPS, actual fault geometry, and earthquake focal mechanisms, the West segment of the Marikina Fault was resolved to be almost fully locked, meaning it is currently accumulating and loading elastic strain, at the rate of 10 to 12 mm/yr. The fault possesses a threat of a large scale

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

with an estimated

between 6–7 and as high as 7.6 to

and surrounding provinces 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. 99 private

village A village is a clustered human settlement or community, larger than a hamlet but smaller than a town (although the word is often used to describe both hamlets and smaller towns), with a population typically ranging from a few hundred ...

s and

subdivisions Subdivision may refer to: Arts and entertainment * Subdivision (metre), in music * ''Subdivision'' (film), 2009 * "Subdivision", an episode of ''Prison Break'' (season 2) * ''Subdivisions'' (EP), by Sinch, 2005 * "Subdivisions" (song), by Rush ...

inside 80

barangay A barangay (; abbreviated as Brgy. or Bgy.), historically referred to as barrio (abbreviated as Bo.), is the smallest administrative division in the Philippines and is the native Filipino term for a village, district, or ward. In metropolita ...

s are traversed directly by the fault and endangers 6,331 buildings in a span of , to where majority are houses with 19 schools included in the list.

References

External links

Valley Fault System (VFS): Marikina Quadrangle
– Philippine Institute of Volcanology and Seismology
High resolution West Valley Fault maps launched - RapplerPHIVOLCS FaultFinder
- This web app is a product of the joint collaboration between PHIVOLCS, DOST, GSJ, AIST. It was developed by Dr. Joel C. Bandibas of GSJ with the cooperation of the research and development personnel of PHIVOLCS. {{SE Asia plates, state=expanded Geography of Bulacan Geography of Metro Manila Geography of Rizal Geology of the Philippines Marikina Seismic faults of Southeast Asia