BACOLOD CITY, Philippines鈥擳he Mines and Geosciences Bureau (MGB) will be tapping experts to conduct an in-depth study of a sinkhole that occurred in Barangay (village) Oringao, Kabankalan City, about 88 kilometers south of here.
鈥淭he study is necessary to determine further steps to ensure the safety of the residents and聽 know the safety measures to be taken and the implications to the stability of the area for construction and other development activities,鈥� said Leo Van Juguan, regional director of the MGB.
According to an MGB report, Jose Gellang said five residents were strolling in the basketball court of the barangay mini plaza when they suddenly fell into the sinkhole around 9 p.m. on June 26. Shaped like a funnel, the sinkhole has an opening of 1.7 meters in diameter, a depth of 3 meters and a base diameter of 3.5 meters.
Other residents went inside the sinkhole to rescue those who fell but Gellang said the smell of gas underneath knocked them unconscious. They were rescued by other residents and brought to the hospital.
The sinkhole has already been cordoned off.
The US Geological Survey defines a sinkhole as 鈥渁n area of ground that has no natural external surface drainage鈥攚hen it rains, all of the water stays inside the sinkhole and typically drains into the subsurface.鈥�
鈥淪inkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground,鈥� it added.
Dr. Lelanie Suerte, MGB senior geologist, said the sinkhole was 鈥渁n action of water,鈥� or caused by water, since no tunnels exist near the area.聽 鈥淚t is possible that the sinkhole might have a wider diameter below the surface but only a portion on the surface has collapsed and gave an opening,鈥� she said.
On June 28, Juguan, along with Suerte, inspected the area and was told by an elderly that a cow had fallen into another hole about 10 meters away but聽 could not be rescued because of its depth.