The Philippine Institute of Volcanology and Seismology (Phivolcs) is studying whether there is a connection between the West Valley Fault and the East Valley Fault.
Ishmael Narag, officer-in-charge of the Seismological Observation and Earthquake Prediction Division of the Phivolcs, on Wednesday said the study is very important in order for them to determine if this would cause a longer rupture should the fault move.
“Part of the study that we are doing is to know if there is a connection between the West Valley Fault (WVF) and the East Valley Fault (EVF). If there is a connection, that would cause longer rupture,” Narag said during a meeting with officials of the Metropolitan Manila Development Authority (MMDA) in Makati City (Metro Manila or National Capital Region, NCR).
Phivolcs, the MMDA and the NCR Police Office (NCRPO) have been locked in meetings to prepare for the region-wide earthquake drill on July 30.
Narag said there is a possibility that when the WVF shakes, it will trigger the EVF.
“So if the WVF moves, it increases the stress toward adjacent faults,” he added.
MMDA Chairman Francis Tolentino said all is set for the first Metro Manila-wide earthquake drill as he urged everybody to participate and cooperate.
He added that the drill will cover 16 cities and one town in Metro Manila, involving 12 million people.
To signal the start of the drill, sirens will blare, church bells will ring and fire alarms will go off.
Phivolcs Director Renato Solidum will make a simulated announcement on radio and television stations that a magnitude 7.2 earthquake has struck along the WFV.
The National Telecommunications Commission (NTC) will also help in disseminating the information by sending a text blast to residents to announce the drill.
The drill will start at 10:30 a.m. and last for a full hour, until 11:30 a.m.
Metro Manila will be divided into four evacuation areas: Intramuros golf course in the west, Veterans Memorial Medical Center golf course in the north, Light Rail Transit 2 depot in the east and Villamor Air Base golf course in the south.
Tolentino clarified that power and communication lines will not be interrupted during the drill.