In celebration of the Ecology Awareness Week, the Environmental Biology Division of the Institute of Biological Sciences held a seminar on “Earthquake Hazards and Risks in Metro Manila and Nearby Provinces” last July 23, 2012; with no less than Dr. Renato U. Solidum, Jr., Director of the Philippine Institute of Volcanology and Seismology (PHIVOLCS) lecturing.
A distinguished geologist and earthquake expert, Dr. Solidum stressed the role of PHIVOLCS in using science to make communities safer. He described earthquakes and presented the hazards and risks that Metro Manila, Laguna and Cavite would face in the event of an earthquake. He also gave instructions on how to survive an earthquake attack.
The Philippines, located along the ‘Pacific Ring of Fire,’ is one of the most disaster-prone countries in the world. A number of natural disasters occur in the Philippines every year, especially typhoons.
However, Filipinos should prepare more for earthquakes than for any other hazards, Solidum said. “This is primarily because earthquakes can cause further destruction such as ground rupture, ground shaking, liquefaction, landslide, tsunami, and fire,” the director explained.
According to Solidum, using technologies at PHIVOLCS, they have already created different scenarios in case active fault lines in the Philippines would move. The active fault line that would affect Metro Manila down to Calamba is the West Valley Fault. PHIVOLCS’ studies show that this fault has moved four times in the past 1600 years with magnitude 7 in the average.
“An earthquake of magnitude 7 is equivalent to 32 Hiroshima bombings,” he analogized the gravity of the number. “When the West Valley Fault moves again, we anticipate intensity 8-9 for Metro Manila and intensity 7-8 for UPLB,” he shared. The last recorded movement of this fault was in August 20, 1653 with a magnitude of 6.9.
“Kapag hindi ka na makatayo, intensity 8 na ‘yon, delikado na,” Dr. Solidum said. He also stressed that the so-called “triangle of life” is untrue because furniture or any object tend to move during very strong earthquakes. Thus, the right thing to do is to go under a table and hold the table’s feet so that it would not move. So, in earthquake drills, what is instructed to everyone is to duck, cover, and hold.
Providing some statistics on the earthquake activity in the country, Solidum showed that “there are 20 earthquakes are recorded per day; 200 earthquakes felt per year; and 90 destructive earthquakes and 40 tsunamis have occurred in the past 400 years.” According to him, a destructive earthquake comes every five years while a destructive tsunami happens every ten years.
Although it is improbable to predict a specific date when a destructive earthquake might happen, Dr. Solidum said that it may occur anytime within 400 years after the 1653 earthquake caused by the West Valley Fault.
While Dr. Solidum gave some grim scenarios that may cause personal alarm, for him, “it is always important that you first give the facts, the real score, to people, and then tell them what to do.” He stressed that the Local Government Units are primarily responsible in implementing the earthquake impact reduction plans that PHIVOLCS provides.
Currently, PHIVOLCS has improved their earthquake monitoring system by acquiring two new processing systems that can detect local and global earthquakes. They are also targeting to increase their station networks from 68 to 85 by 2016.
More information about earthquake (including volcano and tsunami) awareness, preparedness materials, and hazard maps are available on www.phivolcs.dost.gov.ph. A copy of the latest Metro Manila Earthquake Impact Reduction Study (MMIERS, 2004) is available for free from the PHIVOLCS website.