Smaller quakes are better, argues scientist
by C Dematera
Legazpi City (12 February) -- "Smaller earthquakes, although more frequent, are better than one-shot big tremor," declared Delfin Garcia, senior scientist of the Philippine Institute of Volcanology and Seismology (Phivolcs), as he allayed fears of the residents in the earthquake-stricken areas, particularly in Bicol.
Garcia said "residents have been gradually gripping in fears due to the more frequent, thou smaller, tremors that are occasionally shaking their places last month."
He, however, explained that low magnitude earthquakes are better as they served as "outlets" or "releases" that could prevent a stronger or disastrous quake from happening.
"Of course we do not want earthquakes to happen. But if they do, it is better that they come in smaller magnitudes although could be more frequent as this condition could prevent a one-shot, but very strong or disastrous shake," Garcia explained, adding that "the smaller tremors serve as outlets for possible bigger crystal unrest or movement.
He even cited Mayon Volcano, explaining that less hazardous and violent eruption episodes were noted since this country's most active volcano starts to erupt in shorter intervals in 2000, 2001, 2006 and 2009, or restiveness gaps of only one to five years. Mayon used to erupt every ten years, or from 1958, 1968, and 1978.
He noted that Bicol provinces are occasionally shaking because they are situated near the Philippine Trench off Catanduanes waters, while the Philippine Fault line also traverses part of the southern Luzon peninsula.
Tectonic in origin quake of magnitudes 4.6, 6.0, 5.3 and 3.9 that took place on Jan.30, 29, 20 and 11, respectively, shook entire Bicol as well as the nearby Samar and Quezon provinces, as intensities of up to four were felt by the residents, Phivolcs records showed.
According to the senior Phivolcs official, places near fault lines are likely to be hit by strong earthquakes, if smaller tremors are not taking place in these areas for a long time. He cited Haiti as an example.
"Because smaller tremors did not hit Haiti for a very long time, they built most of their houses, buildings and other structures not so much taking into consideration the possible earthquakes that can tear these structures into pieces. In fact there is no existing building code or law in Haiti that prescribes specific strength in their infrastructures," Garcia disclosed.
He also said that if structures in the Philippines would conform to the existing building code, tragedy similar to Haiti could be a remote possibility.
He recalled that the July 1990 earthquake that hit Baguio City and its adjacent provinces was at magnitude 7.9, an earthquake that was far stronger than 7.0 that struck Haiti.
"Since we can not predict when an earthquake could happen, all we need to do is to abide by the laws governing infrastructure constructions," Garcia said.
A series of earthquakes also hit Bicol last year, following a main event of magnitude 5.8 jolter in August 15 last year. (BUCAL/PIA) [top]