Chief seismologist wants audit of structures built before 1992

Ron Gagalac, ABS-CBN News

Posted at Apr 25 2019 04:10 PM | Updated as of Apr 25 2019 09:43 PM

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MANILA - A massive audit and inspection of structures built before 1992 should be done by owners and local governments following consecutive earthquakes that shook Luzon and Visayas this week, the country’s chief seismologist Renato Solidum said Thursday. 

The National Structural Code was given a crucial update in 1992, two years after a 7.8-magnitude devastated Luzon. 

Solidum, director of the Philippine Institute of Volcanology and Seismology (Phivolcs), said building and construction technology has vastly improved since 1992. Houses and buildings built before 1992 might be weaker and unable to withstand earthquakes, he added. 

“Ang dahilan ng pagkamatay ay ang pagbagsak ng mga bahay at gusali, at kailangan magkaroon ng massive structural audit dito sa Metro Manila. Yung mahihina ay dapat matulungang maging matibay o i-demolish o magtayo ng bagong facility” Solidum said.

(Being crushed by fallen structures is one of the main causes of death during quakes, so there’s a need for a massive audit of structures in Metro Manila. Weak structures must either be strengthened or demolished.)

Solidum said the structural audit should be carried out by local government units and establishment owners to ensure the protection of the public in case a massive quake hits the capital.

He also recommended for schools to include in their educational programs ways to prepare for an eventual quake.

THE ‘BIG ONE’

For years, disaster mitigation and management officials have been asking the public to prepare for a massive quake that might hit the capital in this lifetime.

The 100-kilometer West Valley Fault moves every 400 to 600 years. It last triggered a magnitude 6.3 to 6.5 quake in 1648, Solidum said.

Solidum said the fault is ripe for another movement and could trigger an earthquake that might lead to the loss of thousands of lives in Metro Manila and neighboring areas.

Urban planner Arturo Corpuz said ensuring structures are strong is key to preventing loss of lives during a massive quake. However, the reality is many poor Filipinos do not have the means to ensure their homes are resilient to quakes, he said.

“The solution is to help them build homes that are resistant to strong quakes,” Corpuz said.

He advised homeowners and establishment owners to be mindful of the location and geographical conditions of the structures they are buying.

MANILA TRENCH

Solidum also warned of another fault called the Manila Trench, located under the West Philippine Sea.

He said that if the trench moves and triggers a quake with a magnitude of 8 or higher, it could generate a tsunami.

“All shorelines of Western Luzon will be affected by a tsunami. It will enter Manila Bay within one hour,” he said.

According to Solidum, at least 2.5 million people in Metro Manila will be exposed to tsunami, including around 200 schools and 35 hospitals.

Solidum said the government is looking to establish a National Government Center in Clark Air Base in Pampanga to serve as an alternate government operations center in case government offices in Metro Manila shut down. 

Solidum and Corpuz are part of local and international experts who gathered in Manila for a conference on Thursday to discuss the best practices on how to prepare and reduce the risk on events of earthquake.

Experts from Japan, Taiwan, the United States and the Philippines highlighted the importance of illustrating seismic risk profiles at city levels to determine the impact and importance of early warning systems.