'IT'S UNLIVABLE': QC, PHIVOLCS STUDY RENEWS WARNINGS OVER WEST VALLEY FAULT

MANILA, Philippines - Government geologists have found evidence of ground displacement along the West Valley Fault line, validating earlier warnings by national and local authorities that the fault - running 7.2 kilometers from Parañaque through Makati, Taguig, Marikina, to San Mateo along the periphery of Quezon City - remains active.

This came to light as the Quezon City government and the Philippine Institute of Volcanology and Seismology (Phivolcs) on Monday completed trenching work across the West Valley Fault line at Barangay Bagong Silangan, Novaliches. Intended to identify ground rupture movements and slip rates across the fault, the trenching activities found abrupt changes in sediment layers in the area, Quezon City officials said.

The activity involved excavations of two trenches, about 50 meters apart, within a 50-hectare property owned by Banco Filipino at Barangay Bagong Silangan. The area, according to a Metro Manila Earthquake Impact Reduction Study (MMEIRS), shows high susceptibility to earthquakes, along with Barangay Payatas, also in Novaliches.

The exposed trench walls indicated that at least two to three earthquake events had in fact already taken place in the area in the past. Phivolcs is now collecting charcoal pieces for carbon-14 analysis to determine the approximate time of the occurrence of the said earthquakes and the estimate of the age of the sediment layers affected by the ground displacement.

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