Peña: Here We Go Again

Thursday, February 9, 2012

WE HAVE not fully recovered from typhoon Sendong, and here we are faced with another disaster. A magnitude 6.9 Earthquake hit Negros Oriental last February 06 and caused widespread devastation. As of February 09, there were 26 confirmed dead, 52 injured and 71 missing according to NDRRMC.

Aftershocks are felt every now and then. According to the NDRRMC’s latest bulletin, a total of 1,238 aftershocks have occurred after the main 6.9-magnitude quake. However, only 75 of these aftershocks were felt, the strongest of which is magnitude 5.2.

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Pictures and videos taken from the earthquake-hit areas show severe damage to infrastructure. Ten bridges were damaged and several roads were impassable. Some buildings, houses and churches collapsed totally while others sustained damages, which made them uninhabitable. Property damage as estimated by the NDRRMC is P266 million.

What makes this recent earthquake nerve-wracking is that it occurred in an active but previously unmapped fault. That meant the area was not prepared for this type of disaster. Phivolcs admitted that they lack high-resolution topographic maps as well as experts skilled at active faults mapping. Their geologists are leaving the agency for more attractive career opportunities.

The Philippines is indeed a disaster-prone country. We get 20 typhoons a year. We are located in the so-called Pacific Ring of Fire, so we have volcanic eruptions and earthquakes. We have records floods and volcanic eruptions. The eruption of Mt. Pinatubo is the second largest in the twentieth century.

Restless Earth

The Earth’s surface is constantly moving. Natural forces cause it to twist and turn. The magnitude 8.8 earthquake in Chile in 2010, one of the ten strongest earthquakes ever recorded, “twisted” the earth. Scientists at NASA’s jet propulsion laboratory calculated that the quake should have shortened the length of day by about 1.26 microseconds and shifted Earth's figure axis by about 8 centimeters (3 inches).

The magnitude 9.0 earthquake in Japan last year has moved that country closer to the United States by 8 feet. The earth’s rotation was affected too. Research scientist Richard Gross of NASA's Jet Propulsion Laboratory in California calculated that the Japanese earthquake should have caused Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds (a microsecond is one millionth of a second).

The Earth is also moving as a result of global warming. According to livescience.com, researchers have found that the shift of water mass around the globe, combined with so-called post-glacial rebound, is shifting Earth's surface relative to its center of mass by 0.035 inch a year toward the North Pole. Post-glacial rebound is the response of the solid Earth to the retreat of glaciers and the resulting loss of the hefty weight.