Short buildings more vulnerable to 'The Big One,' says Phivolcs

MANILA -- Should a 7.2-magnitude earthquake dubbed the "Big One" hit Metro Manila, short buildings will sustain heavier damage than skyscrapers, the head of the state seismology office said Wednesday.

The potentially destructive quake would come from the West Valley Fault that stretches from Bulacan to Laguna and passes through the capital, said Phivolcs Executive Director Renato Solidum. 

"When the fault is very near us, the vibration of the ground is very fast. If that is the case, then the shorter building will be swayed more than the tall building," he told ANC. 

"Let me use an analogy... You're very angry with a person and you want to shake that person. Which is easier for you to shake: a person who is short and thin or a person who is tall and heavy? The short and thin one, right?" he added. 
 
The Big One could produce an intensity 8 shaking that would make even standing up difficult in Metro Manila, Bulacan, western parts of Rizal, and northern parts of Laguna and Cavite, said Solidum. 
 
The 100-kilometer West Valley Fault moves every 400 to 600 years and triggered a magnitude 6.3 to 6.5 quake in 1648, he said.

A separate fault between Zambales and Pampanga provinces moved during the afternoon rush hour on Monday, triggering a Magnitude 6.1 quake that hit Central Luzon, killing at least 16 people and shutting Clark Airport for 48 hours, Solidum earlier said. 

On Tuesday afternoon, a Magnitude 6.5 temblor hit rocked parts of Visayas, and Bicol and Caraga regions. It injured at least 5 people and cracked some buildings.

This week's 2 quakes were "not related," said Phivolcs. 

• Don't panic, be calm, says Phivolcs following aftershocks

ANC, 24 April 2019