Phivolcs: West Valley fault line 'ripe for movement'

The Philippine Institute of Volcanology and Seismology on Wednesday said the West Valley fault line, supposedly capable of producing a 7.2-magnitude earthquake, is ripe for movement. "Ripe na gumalaw ang fault. Napakataas ng probability na gumalaw ito in the future, hindi lang natin masabi ng exact date and time," Phivolcs deputy director Bartolome Bautista said during a Senate inquiry on the country's disaster preparedness on Wednesday. (The fault is ripe for movement. There is a high probability that it will move in the future, we just cannot say the exact date and time.) Bautista explained that the earthquake fault, which runs from the Sierra Madre mountain range to Tagaytay, moves every 200 to 400 years. The last time that the fault moved was 200 years ago, he said. "Pumapasok na siya sa recurrence time, pasok sa cycle (It fits the recurrence time, it fits the cycle)," he said. Bautista said they cannot yet determine what would trigger the fault's movement but that they are relying on pre-quake shocks to signal its movement. "Iba-iba yung pag-uugali ng faults (Faults move differently)," he said. Reinforcement of structures During the Senate inquiry, Public Works Secretary Rogelio Singson said they have identified nine bridges that need to be repaired and 11 other bridges that have to be retrofitted to withstand stong earthquakes. Singson said they are working with the Philippine Institute of Civil Engineers to assess old, private high-rise buildings, especially those that are at least 15 years old. They have already assessed 1,100 public buildings in Metro Manila, some of which he said they have condemned. Singson said infrastructure in the provinces will also be assessed. "We have directed all building officials in their areas of jurisdiction (to do the same)," he said during Wednesday's Senate hearing. Senators Loren Legarda and Juan Miguel Zubiri, however, asked Singson to give priority to inspecting the mass transit systems in the country. As of posting time, the Senate inquiry was ongoing. Disaster preparedness The Senate inquiry on the country's disaster preparedness on Wednesday was being conducted by two Senate committees — environment and natural resources and climate change. The senators are conducting an investigation into the government's preparedness for natural disasters similar to the magnitude-9 earthquake that recently hit Japan. Click here to view hi-resolution map "We shall focus on the technical aspects of our local disaster preparedness... as well as the state of the country’s early warning system for disasters such as tsunamis and earthquakes," said climate change committee chairman Senator Loren Legarda. Aside from the inquiry into the "structural integrity" of the country's buildings and civil infrastructure, the senators also want to determine whether the country's utilities have back-up systems for times of disaster. - VVP/HS, GMA News