HOW THE MARIKINA VALLEY FAULT SYSTEM CAME TO PUBLIC KNOWLEDGE?

 

HOW THE MARIKINA VALLEY FAULT SYSTEM

CAME TO PUBLIC KNOWLEDGE?

          “And in that hour a great earthquake occurred, and a tenth of the city fell; and seven thousand persons were killed by the earthquake, and the rest became frightened and gave glory to GOD of heaven.”

                      – Revelation 11:13, New World Translation of the Holy Scriptures.

        Three decades ago, noone gave a damn concern about a long and huge subterranean crack traversing from the Sierra Madre Mountain in northeastern Luzon crossing the eastern side of Metro Manila down to the western banks of Laguna de Bay to the Taal Lake. The scientific community only recognized its existence in 1923, and they didn’t even know where exactly it is, its extent, geography and history. It is not mention except in the pages of old geological records, and obscured and almost faded documents in the former Philippine Weather Bureau dockets.

        I confess! I admit that I am an accomplice of the person respondible for divulging the information.

        It all started around September 1990, barely two months after the devasting Magnitude 7.7 earthquake that hit Baguio and Cabanatuan. I was at Ma Moon Luk in Quezon Boulevard, together with GMA-7 and DZBB broadcast journalist and news reporter Lito Viilarosa, cause-oriented organization Lupang Ugnayan founder Dominador Arellano, a geodetic engineer (I couldn’t yet recall the name), and Elpidio “Ka Pidiong” de Chavez, a civic leader from Sampaloc. It was a meeting regarding how to help a community whose people were about to be victims of “illegal” demolition by a supposed claimant to the land they were occupying, the land title of which we found to be dubious.

        To cut the long story short, after the intended talks, we ate, and the topic of conversation shifted to the recent earthquake. We wondered why the earthquake intensity (VII) in Metro Manila was so strong when its epicenter was around 200 kilometers away. My answer, as well as that of our geodetic engineer companion, was because of the soft soil subterranean geomorphology of the metropolis. Villarosa, on the other hand, presented a question: “Paano kung may malaking faultline na dumadaan sa Metro Manila?” (What if there is a huge faultline that traverses Metro Manila?). We agreed that it is a valid causal factor.

        Villarosa had become a close friend of mine ever since I first met him during his Tulong Madla days at the Radio Mindanao Network after I graduated from college. We share many similar interests with regards to science, philosophy and views on activism, ideological perspective, and even with regards to biblical teachings. Looking at his face, I knew then that he has uncovered something, but it will be months later before he shared it publicly.

        I myself have had some inklings that there are faults/faultlines inside and within Metro Manila when I was in my graduating year in college. I remember the first instance that aroused my curiosity involved the thesis about the Light Railway Transit (LRT) System of a classmate of mine, David Padua. He asked me if I could help him gather technical research materials. As it turned out, the geomorphologic survey – soil tests – along the LRT route revealed some startling underground strata anomalies, especially near the crossing on both banks of the Pasig River. Huge displacements were observed in these areas in the last five decades. I have a hunch but couldn’t yet fully understand what I discovered until years later (That is after I read the UNDRO Report).

        Another instance that I could recall was when I was apprenticing with ADD-Mayer (around 1987). Architect James Na, the company’s manager was relating about an incident with engineers Teopilo Go and Freddie Ong, and me. The incident was about a 20-meter concrete pile that sunk so deep after just one blow from a pile driver that one would think the underground was hollow.

        All these geomorphologic curiousities led to something really huge!

PHILVOLCS 1991 Mapping of the MVPS,
and the subdivsions where the faults traverse.

        Villarosa began a series of intermittent exposé regarding the controversial Marikina (Valley) Fault System, initially called Marikina Faultlines. Different sectors of the scientific community took interest on the matter, including then PHIVOLCS Director Raymundo Punongbayan. Others tried to debunk the exposé. There was even this geologist from the University of the Philippines (UP) who said “the report is a farce since it was commissioned by Imelda Marcos.” That closed-minded fellow insisted the “fault is long dead!”

        According to Villarosa, he saw a bunch of documents in a junk bin at the hallway of the Ministry of Human Settlement on its way to be incinerated. The ministry was dissolved by the vindictive Cory Aquino Regime owing to the fact that the ministry was founded by First Lady Imelda Marcos. When Villarosa tried to read the contents, it turned out to be a 1976-1977 report of the United Nations Disaster Relief Organization (UNDRO) Coordinator to the Human Settlement Commission (HSC), detailing a systematic vulnerability analysis of Metro Manila area with regards to risks from disasters like earthquake and flood. There was also a comprehensive report regarding the Marikina Valley Fault System (MVFS) and its branches.

        When Villarosa ask the supervisor why they were throwing away such valuable documents, the answer was “Ang utos sa amin ng Malacañang ay sunugin lahat!” (Our order from Malacañang was to burn everything!). He then took it upon himself to get and save as much of the documents as he could.

        Every day for months he would read and review the contents of the documents. He asked two of his professor-friends for comments, one from the Pamantasan ng Lungsod ng Maynila (PLM), which he was an alumnus, and the other from UP. Finally, he gave me a copy of the documents and asked me to help him understand what they were. Together, we conducted extensive research on the subject.

          The documents were very interesting to me because it is related to my profession as a structural engineer – knowing areas where earthquake damage can be prominent is an important part of structural design.

        I also asked my former professor at the University of Santo Tomas (UST) Faculty of Engineering, Francisco Limeta, who is knowledgeable with seismology and earthquake engineering, for his opinions. Professor Limeta was quite amazed and surprised about the contents of the documents, especially with regards to the Marikina Valley Fault System. He consulted their records at the National Society of Seismology and Earthquake Engineering of the Philippines (NASSEP). He told me that based on their available records of investigations especially those he himself conducted in the 1980s, two earthquakes during the 17th century could have emanated from the (MVFS), the November 30, 1645 and the August 20, 1658. The conclusion arrived at was that MVFS is neither dead nor dormant; it is very much active. He also added that “there are two other suspected faults arising from fault traces perpendicular to the MVFS within the Pasig River delta which was tentatively labeled as Manila Faults 1 and 2.” No extensive study was made on these faults as they are under a heavily-populated residential area (This was also mentioned in the UNDRO Report).

        I, myself, was able to gather some related reports: 1) A 1984 HSC study report that indicated a portion of Metro Manila, west of the Marikina River and atop the Pasig River delta, and the Tondo foreshore area, had sunk about 18 inches in two and a half decades, 2) An addendum to a 1988 soil test report on a propose project’s site in Pandacan, Manila, submitted to Dynabuilt Construction, the company I was working with at the time, observing a soil displacement of around two feet in the area in a very short span of more or less 20 years, and 3) The geomorphologic curiousities I mentioned earlier.

        Villarosa continued his series on the MVFS existence in his radio program at DZBB. Meanwhile, Director Punongbayan initiated a study and investigation on the possibility that the MVFS is active. He was alarmed at the initial findings. Field mapping augmented by topographic map and air photo interpretations conducted in April and May (1991) of the Marikina Valley and surrounding areas revealed previously unrecognized geologic and geomorphic evidences for the recent activity of the said fault system. He immediately ordered trenching and extensive mapping of the fault system.

        In its early mapping of the MVFS (SEE attached PHIVOLCS 1991 Mapping), PHILVOLCS identified several subdivisions on top and on the direct path of the faults itself: Amityville, Christineville, Violago Homes, BF Homes, Payatas Subd., Bagong Silangan Subd., Filinvest Homes, Doña Ana Village, Sunnyside Subd., Capitol Park Homes, Capitol Hill Subd., Loyola Grand Subd., La Vista, Loyola Grand Villas, Loyola Heights, Loyola Subd., Cinco Hermanos Subd., Provident Subd., Industrial Valley Subd., St. Ignatius Village, White Plains Subd., Corinthians Garden, Green Meadows, Valle Verde. These areas are designated “extremely vulnerable” to earthquake damage.

        The continuous mapping of the MVFS was, however, temporarily stopped due to the lobbying of some subdivision developers. According to Director Punongbayan, “Nalulungkot ako sa development, pero itigil daw muna until further notice sabi ng office of the president (Cory Aquino)” (I’m sadden by the development, but the order from the office of the president is to stop until further notice). It seemed Malacañang believed the UP geologist who said the “fault is long dead,” than the evidences we gathered. The investigation of Metro Manila earthquake vulnerability, unlike its predecessor, was not a priority of the Cory regime.

        The controversy was followed by another overwhelming disaster, Mount Pinatubo showed signs of awakening from its dormancy and eventually started erupting in June 1991. The focus shifted.

        During another meeting, Villarosa and I talked about the possibility that the July 16, 1990 earthquake is connected to the eruption of a long-dormant volcano. The question that followed was, “Could that earthquake also awaken a long-dormant fault system?” Director Punongbayan said “the probability is very high.” Together we did what we could to relay the information about the MVFS to the public despite Malacañang’s gag order. Director Punongbayan asked the help of his colleagues in the United States Geological Survey (USGS); Villarosa continued bringing it up on his radio program; and I talked to Mrs. Ernestina Evora Sioco, editor-in-chief of MOD magazine, if I could write an article about it which she readily agreed when I told her about the worst-case scenario.

Cut-out map shows the Marikina Valley Fault System (MVFS),
traversing Metro Manila, and two other suspected faults,
perpendicular to MVFS within the Pasig River delta.

        Finally from October 1991 onward, Villlarosa and I simultaneously revealed to the public all that we have uncovered: Villarosa through a full-blown information campaign in the broadcast media, radio (DZBB) and television (GMA-7), and me through the pages of MOD magazine in an exclusive three-part special report, The Philippines Land of Earthquakes and Volcanoes. This special report won for me my first Philippine Press Institute (PPI) Science and Technology Journalism Award, and the National Achievement Award given by Atlas Publishing Company.

        The science community, in particular, and the public, in general, finally took notice. We even attracted investigators from foreign institutions involved in earthquake research. And the rest is history.

 

P.S. What about Manila Faults 1 and 2?

 



Lito Villarosa,
during his Radio Patrol (RP1) days
at DZMM (1987).

THIS BLOG ARTICLE IS IN MEMORY OF LITO VILLAROSA (July 23, 1956 – February 2, 2000), BROADCAST JOURNALIST, AND A VERY CLOSE FRIEND, WHO WITHOUT HIS KEEN INTEREST, INITIATIVE, AND EFFORT, WE WOULD STILL BE IN THE DARK ABOUT THE MARIKINA VALLEY FAULT SYSTEM, A VERY REAL AND IMMINENT SEISMIC THREAT TO METRO MANILA AND ITS SURROUNDING SUBURBS.

 

WALL PHOTO INFO:

Jones Bridge in Manila.

Built in 1916; detroyed during World War II;  and rebuilt in 1950. It sustained minor damage during the July 16, 1990 earthquake. Retrofitted and restored in 2019 with a cost of 20-million pesos, funding coming from Chinese-Filipino businessmen. The bridge, together with the structures on the background, incidentally, is within the Pasig River delta, of which two suspected faults, Manila 1 and 2, supposedly traverse perpendicular to the Marikina Valley fault System.