THE Philippine Institute of Volcanology and Seismology (Pivolcs) denied reports over the weekend that it had warned against a strong earthquake in Metro Manila and nearby provinces between February 24 and March 28. This is supposed to be the long-feared “Big One” expected in the area covered by the “West Valley Fault.”
Talk of a strong earthquake must have been encouraged by the series of quakes that began with one of 6.7 magnitude that struck Surigao del Norte last February 10, killing at least eight people and injuring more than 200 others. It was the strongest earthquake to hit the area in this century.
Phivolcs recorded a total of 244 aftershocks after the 6.7-magnitude earthquake in Surigao del Norte. There was a succession of tremors variously measuring 4.9 to 4.1 magnitude recorded in various areas of Caraga, Davao, and Soccsksargen, spreading fear among the residents. Last Sunday, some two weeks after the big Surigao quake, Phivolcs reported a big offshore quake that created a surface wave in the magnitude of 5.0 in the Pacific some 123 kilometers east of Burgos, Surigao del Norte.
It is no wonder, therefore, why after the big Surigao earthquake followed by several others in the area, fears of the “Big One” long expected in Metro Manila again surfaced. Last year in June, a “Shake Drill” was held with thousands of people taking part in earthquake drills in Metro Manila as well as in the nearby provinces of Bulacan, Cavite, Rizal, and Laguna. These are the principal areas sitting on top of the West Valley Fault today. The Fault is said to break roughly every 400 years. The last major earthquake generated by the Fault was in 1658, 357 years ago, so the “Big One” could come at any time now.
Phivolcs last weekend denied having warned against a strong earthquake between February 24 and March 28. There is indeed no way to know when an earthquake will strike. It will just hit us when the endlessly moving earth segments grinding against each other reach their breaking point.
That point could come at anytime as we approach the 400th anniversary of the last time the West Valley Fault snapped in 1658. This is why we have been holding yearly shake drills, so that we may avoid the big number of deaths that could result in a 7.2 earthquake in Metro Manila. That death toll could reach 34,000, according to a study by the Japan International Cooperation Agency (JICA), with 100,000 others injured in the collapse of buildings.
Phivolcs is not predicting anything as definite as a February 24 to March 28 date for “the Big One” but we must be prepared for it. We must know what to do during and after the disaster, what to have ready at all times, such as food and emergency medical kits, where to go for medical help, etc. We are getting closer to the 400th year after 1658 when the West Valley Fault last triggered a major earthquake and the next one could come any time.