CEBU, Philippines - The magnitude 7.2 earthquake and a string of aftershocks may have triggered the formation of a sinkhole resulting the collapsed of the 21-unit apartment affecting 16 families in Lapu-lapu City.
The Mines and Geo-sciences Bureau of the Department of Environment and Natural Resources-7 has conducted a site assessment yesterday on the reported sinkhole formation in Sitio Kapayas, Barangay Canjulao, said city.
DENR-7 information officer Eddie Llamedo said the earthquake may have caused ground or tension cracks and these factors may have weakened the cave roof.
The caved-in portion measures 40 meters by 60 meters in diameter and a depth of two meters.
The apartment units owned by James Berdin were constructed in the late 1990s on top of the cave’s roof filled-up only of stonecraft and waste materials.
“Gitukod ang apartment units on top sa langob unya gibutangan lang og mga waste materials ug stonecraft ang ibabaw,†Llamedo said.
Llamedo added that DENR-7 recommended the evacuation and relocation of the affected families.
“We encourage our communities to report immediately to their barangay officials if there are sinkholes that are forming and people should be kept away from these sinkholes,†said DENR-7 Regional Executive Director Isabelo Montejo in a statement.
A sinkhole is a natural depression or hole in the surface topography caused by karst processes - the chemical dissolution of carbonate rocks.
As precautionary measures, MGB-7 Regional Director Loreto Alburo, said that the bureau initially recommended the appropriate installation of fence or barrier of the affected area, proper signage or warning, and continuous monitoring of the subsidence by the local government units.
It can be recalled that the rapid geo-hazard assessment on rain-induced landslides and flooding in 2009, a team of geologists from the MGB-7 observed the presence of sinkholes in 14 barangays in Cebu province.
These are barangays of Bulwang, Lusong, Montealegre, Santo Niño, Siotes, Kabkaban, Libo, Taminjao, Kalangahan, Bagasawe, and Sandayong, all in Tuburan.
On the other hand, barangays Linut-od in Argao, Kang-actol in Dumanjug, and Vive in Ronda, Cebu were observed to have sinkholes. (FREEMAN)