Phivolcs chief warns 7.2 earthquake can isolate Manila

MANILA, Philippines — Top state seismologist Renato Solidum on Wednesday urged organizations and local officials to systematically devise mechanisms to lessen damage and casualties if a 7.2-magnitude earthquake hits Metro Manila.

Speaking to disaster risk experts at a summit broadcasted over radio on Monday, the Philippine Institute of Volcanology and Seismology (Phivolcs) director said that the capital region faces isolation due to collapsed roads and buildings as well as fires.

Solidum explained that a movement in the West Valley Fault, estimated to generate a 7.2-magnitude earthquake, can heavily damage over 100,000 residential buildings. The fault system that runs north to south along the west and east edges of the Marikina Valley poses the greatest threat to Metro Manila.

Metro Manila may be separated into four isolated zones based on geography. Collapsed buildings in Makati and Mandaluyong cities as well as the Pasig River may separate northern and southern parts of the metropolis, while broken road networks will isolate the west and east of the capital.

Manny de Guzman, president of Asia Pacific Institute for Green Development, likened the scenario to the isolation of Baguio City, which was hit by the disastrous 7.9 magnitude earthquake in 1990 .

"Given this grim disaster scenario [in Metro Manila], the rest of the country will have to be well prepared to help quickly, in a coordinated and efficient manner, and with sufficient skilled responders and logistics, particularly for search and rescue and emergency relief, which I believe will be initially dependent on the use of choppers," De Guzman said in a Facebook post.

Solidum also reiterated that the potential quake is foreseen to cause the deaths of 31,000 people and hurt as many as 110,000 given Metro Manila's dense population of almost 10 million.

Besides the threat of an earthquake, Metro Manila is also vulnerable to tsunamis based on historical records showing waves entering from the port of Manila, Solidum said.

Jerry Velasquez, United Nations International Strategy for Disaster Reduction regional coordinator, explained in a Facebook post that the magnitude 7.2 earthquake is "not a prediction over a specified time."

"Rather it is the estimated largest credible earthquake that can be generated by movement of the Valley Fault System--which runs right through Metro Manila--based on available geological and seismological data," Velasquez explained.

This indicates that over an unspecified time, movement of the fault system is "inevitable," he added.

"We do not know, however, when this will happen. Earthquake prediction is still an elusive quest anywhere in the world. For an appreciation of the risk, suffice to say that historically, the Metro Manila area has indeed been repeatedly affected by disastrous earthquakes," Velasquez also said.

Citing the MMEIRS, the UN official recommended high-priority action plans including the promotion of disaster resistant urban development, re-development and research and development on strengthening buildings. - with reports from Perseus Echeminada