Phivolcs: Magnitude 6.1 quake won’t trigger tremors from West Valley Fault

enablePagination: false
maxItemsPerPage: 10
maxPaginationLinks: 10

Metro Manila (CNN Philippines, April 23) — The Philippine Institute for Volcanology and Seismology (Phivolcs) assured that the magnitude 6.1 quake that rocked Luzon yesterday afternoon would not cause more quakes coming from the West Valley Fault.

“The earthquake yesterday would not trigger the movement of the West Valley Fault, it’s so small. But the West Valley Fault can move because it is independent of the fault that moved yesterday to cause the Magnitude 6.1 earthquake,” Phivolcs director Renato Solidum told CNN Philippines’ The Source on Tuesday.

Officials have been warning of a possible magnitude 7.1 quake originating from the West Valley Fault, a 100-kilometer fault cutting through Metro Manila from Bulacan down to Laguna, which they have said is ripe for movement.

READ: DILG: More preparations needed for the 'Big One'

Following the tremor yesterday, warnings have popped up on social media about an impending magnitude 7.1 quake that will affect Bulacan, Quezon City, Markina, Pasig, Makati, Taguig, Muntinlupa, Rizal, Cavite at Laguna.

Phivolcs said this was lifted from the government’s plan in case a massive quake hits Metro Manila, but the messages that spread omitted the planned response of government agencies.

It added that this warning has no basis. It also does not say that technology that can predict when an earthquake would happen exists.

“The Phivolcs-DOST is not giving a warning for an impending earthquake. We are using a scenario for all of us to prepare for because otherwise, we don’t have an idea how serious the preparedness should be. So we are not warning, but there is a possibility that there is a strong earthquake,” Solidum said.

Prepare for worse

The quake toppled some structures in Pampanga, including portions of the Clark International Airport and a supermarket. Sixteen have been reported dead.

Meanwhile, some pools on upper floors of condominiums in Metro Manila spilled over the buildings due to the earthquake.

However, Phivolcs does not consider it as a major earthquake, as it was only a magnitude 6.1 on the Richter scale, which is used to tell the energy of a quake. A major earthquake would measure magnitude 7 and above.

“Use what happened yesterday as a reminder. When a strong earthquake event and not even a major earthquake event can damage structures, how much more if the shaking will be quite strong?” Solidum said.

He said houses and buildings need to be checked if they have been constructed properly and undergo a structural audit.

He added that people should know where they would need to evacuate to in case of an earthquake and have a bag containing emergency essentials like flashlights and batteries ready.

Metro Manila Development Authority (MMDA) chair Danilo Lim has directed all Metro Manila Disaster Risk Reduction and Management Councils to inspect all government buildings and infrastructures in their respective areas following the strong quake.

The MMDA also reiterated the government’s five-year-old plan in case a magnitude 7.1 quake—dubbed as “The Big One”—hits Metro Manila.

Under the plan, Metro Manila is divided into four quadrants: the north quadrant composed of Caloocan, Quezon City, Valenzuela, San Juan and Mandaluyong; the east quadrant composed of Pasig and Marikina; the west quadrant composed of Manila, Malabon and Navotas; and the south quadrant composed of Las Piñas, Makati, Muntinlupa, Parañaque, Taguig, Pateros and Pasay.

Residents from the north quadrant will evacuate to the Veterans Memorial Medical Center and the University of the Philippines campus. Those from the east quadrant will head to Marikina Boys Town, the Red Cross Compound in Marikina and the PhilSports Arena.

West quadrant residents will go to the Intramuros Golf Course, while those from the south quadrant will evacuate to the Villamor Air Base Golf Course.

Michael Salalima, MMDA Disaster Risk Reduction Management Council chief of staff, told The Source that they are reviewing the plan, particularly for the east quadrant where the emergency field hospital would be located at the LRT 2 Santolan Station Depot.

“We are still identifying another staging area because medyo delikado ho diyan [it is quite dangerous there] because of the powerlines of the LRT,” Salalima said.