The Philippine Institute of Volcanology and Seismology (Phivolcs) yesterday identified two more cities and 12 municipalities in the province of Cebu as susceptible to earthquake-induced landslides.
Engineer Robinson Jorgio, Phivolcs-Cebu chief based in Lapu-Lapu City, explained the potential hazard is present in mainland Cebu as it is dominantly underlain with limestone which is dissolved easily by water that eventually creates underground caves or sinkholes.
He urged engineers and developers to intensify the conduct of ground explorations before building structures.
“Earthquakes can cause natural hazards everywhere like tsunamis on coastal areas, or liquefaction in plain terrain or landslide in mountains. But you just have to apply the right engineering measures or other instruments to minimize the adverse effects,” Jorgio explained.
Before building houses, he said, precautionary methods such as geo-technical exploration have to be employed to avoid critical or high-risk areas or to ensure safety of people.
Aside from the City of Naga, the cities of Talisay and Danao and 12 towns in the Cebu have been marked red which means they are vulnerable to earthquake-induced landslides.
The towns in the south are Minglanilla, San Fernando, Argao, Dalaguete and Alcantara. In the north are Consolacion, Compostela, Tabogon, Carmen and Medellin and in the west are Pinamungajan and Asturias.
The 20 September tragedy in the City of Naga exposed natural hazards that were unknown previously to many residents and even local leaders.
Experts disclosed that Naga sits on a karst terrain with numerous sinkholes and underground caves that gradually degraded or weakened as earthquakes shook the area.
The series of seismic activities disrupted the subterranean flow of groundwater.