At 10:02 a.m. yesterday, a 6.4 magnitude quake rocked Jose Abad Santos in Davao Occidental and the seismic force was felt in Davao City, 229 kilometers away.
We will never get tired of reminding everyone to always employ preventive measures to be safe. This is especially true since Davao City is sitting on six active faults.
These have been identified by the Philippine Institute of Volcanology and Seismology as the Tamugan fault (Matulog District), Lacson fault and Dacudao fault (Caliban District), Colosas fault (Paquibato), Biao Escuela fault and New Carmen fault (both in Tugbok District).
This is why the project of the Department of Science and Technology, which released at Atlas that identify potential danger areas in Davao City should be commended. It’s meant to be the Bible of contractors and engineers when building a house or building. If the location is on ground zero, they have to reinforce the structure to make it quake-proof.
With that said, it’s our responsibility as Davaoeños to ensure our houses can withstand a strong quake. A strong earthquake is defined as a seismic activity that can cause heavy damage in a densely populated area. It registers between 6.0 and 6.9 on the Richter’s scale.
The most common myth is that skyscrapers are vulnerable to strong quakes. It’s actually the smaller buildings–from two-stories to five-stories–we should be wary about. They are stiffer and less flexible. They don’t sway as much compared to a 20-story building so less energy is required for it to collapse when the ground shakes.
Newer buildings now are equipped with base isolators, which isolates the base of the structure as the ground sways. However, the location is also a factor. For instance, buildings erected on softer soils are more vulnerable compared to a bedrock. The softer soil becomes even more dangerous if there’s water underneath as the earthquake will trigger a natural phenomenon called liquefaction. This makes it more likely for the ground to swallow your house whole.
It’s best to revisit the blueprints for your house or commercial building. Also, get your house reassessed by structural engineers for resiliency and vulnerability. Sure, you will incur some costs in the process but in the end, it’s about making sure your loved ones are safe.