Following Wednesday’s massive earthquake that rocked the eastern seaboard of Mindanao and killed seven people, hundreds of aftershocks were felt throughout the island.
For instance, the town of Tulunan suffered three strong aftershocks on Saturday alone—the strongest of which hit magnitude 5 on the Richter scale. On Sunday afternoon, two more aftershocks—at 3.9 and 3.2, respectively—only added to the trauma of the residents.
In fact, according to Renato Solidum, Philvocs director, they recorded more than 600 aftershocks since the magnitude 6.3 quake on the night of Oct. 16.
But this is hardly surprising, depending on the magnitude of the quake, the aftershocks can range from hundreds to thousands in a span of weeks through months. Most are too weak to be felt, however. Although it is not common, the aftershock can be stronger than the main earthquake. In this case, it is then referred to as the foreshock.
Apart from causing sleepless nights from the already traumatic community, aftershocks are also very dangerous. If the structural integrity of a building is compromised due to the main quake, the aftershock can cause it to collapse. This is the reason why the first few hours following the earthquake is crucial.
Government engineers should immediately sweep structures to determine if they are still safe for the occupants inside. It was also the reason why Mayor Sara Duterte rightly called off classes the day after the earthquake to give the Department of Education and private institutions to inspect their buildings.
We should never underestimate the danger of the aftershock. Safety measures and risk awareness centering on aftershocks should also be included in the modules taught in schools, businesses, and vital installations. When a strong earthquake occurs, our alert level should be always up until the risk has subsided.
