The Mines and Geosciences Bureau 7 classified a newly discovered sinkhole in Sitio Indilicio, Purok Libog 1, Barangay Guadalupe, Bogo City as a high-risk ground collapse area in an Aug. 24, 2026 advisory.
Field and radar surveys showed the sinkhole measured about 15 meters by 25 meters, had widened by roughly two meters, and continued to expand with ongoing rim collapses and rumbling sounds.
MGB 7 recommended a 20-meter no-entry zone from the rim and a 50-meter controlled-access zone, advising residents to evacuate preemptively during heavy rain and report ground changes.
A NEWLY discovered sinkhole in Barangay Guadalupe, Bogo City, northern Cebu, is still growing, raising concern in a city where sinkholes were documented after the magnitude 6.9 earthquake on Sept. 30, 2025.
The Mines and Geosciences Bureau (MGB) 7 classified the site in Sitio Indilicio, Purok Libog 1 as a “high-risk ground collapse area” in a geohazard threat advisory dated Aug. 24, 2026.
It said portions of the rim continue to collapse. Geologists also heard rumbling sounds during their assessment, which could indicate continuing subsurface collapse.
“Field and radar surveys show that the sinkhole in Sitio Indilicio is still expanding, with rumbling sounds and groundwater flow indicating a wider underground cavity system,” MGB 7 said.
An active, expanding sinkhole
The ground depression was first reported at 4:45 a.m. on Aug. 20. During an assessment on Aug. 22 and 23, the sinkhole measured about 15 meters by 25 meters and had widened by roughly two meters.
Field observations and drone images indicated a subsurface cavity at an estimated depth of about 15 meters. The nearest house is about 18 meters from the rim.
The collapse adds to ground hazards recorded in Bogo since the 2025 earthquake. Before MGB 7 completed its assessment of the Guadalupe site, Bogo officials described it as the 20th sinkhole recorded in the city.
As of Oct. 12, 2025, MGB 7 had validated 16 sinkholes in Bogo. Around 15 sinkholes were also reported in the sea near the mini fish port in Barangay Nailon following the earthquake.
How the sinkhole formed
MGB 7 classified the Guadalupe formation as a cover-collapse sinkhole. This type forms when soil or other loose material above an underground cavity loses support and falls into the void below.
In limestone areas, groundwater can gradually dissolve rock and enlarge cracks and cavities beneath the surface.
The bureau has said much of Cebu is underlain by soluble limestone and that the Sept. 30 earthquake destabilized some sinkholes and cave systems in northern Cebu.
At the Guadalupe site, geologists found clayey material, evidence of groundwater flow and a cavity beneath the collapsed ground.
The bureau has not established the cavity’s full dimensions or how far it extends. While earthquakes can trigger collapses in areas with existing underground cavities, the MGB 7 has not said that the Aug. 20, 2026, sinkhole was caused by the 2025 earthquake.
Possible underground links
MGB 7 said two other cover-collapse sinkholes are located near the newly discovered sinkhole in Barangay Guadalupe. One is about 100 meters southwest of the new collapse and the other about 65 meters northeast. Both formed after the Sept. 30 earthquake, according to the bureau.
Their locations suggest that the three sinkholes may sit above an interconnected or laterally extensive underground cavity or conduit system, although this has not been confirmed.
Ground-penetrating radar was used to examine the area, but clayey material weakened the signal beyond a depth of about five to six meters. The survey could not determine the cavity’s full depth or lateral extent.
Other parts of Bogo have also drawn attention for sinkhole hazards. Aside from the collapses reported in Barangay Nailon, the MGB 7 identified sinkhole-prone areas in Barangay Cogon during post-earthquake assessments in October 2025.
Risks to residents
The MGB 7 recommended that the Bogo City Government establish a no-entry zone extending at least 20 meters from the Guadalupe sinkhole’s rim and widen it if the collapse progresses.
It also recommended a 50-meter controlled-access zone for residents and responders.
Residents have been advised to evacuate preemptively during heavy rain and report new cracks, unusual sounds or other changes to the Bogo City Disaster Risk Reduction and Management Office.
The precautions come less than a year after the earthquake displaced thousands in Bogo. As of Oct. 18, 2025, the Department of Social Welfare and Development recorded 998 displaced families, or 4,499 people, in the city.
Barangay Cogon became one of the temporary shelter sites for earthquake victims.
Residents near the Guadalupe sinkhole may also need to evacuate or relocate if the collapse moves toward houses, particularly during heavy rain or earthquake-related ground shaking.
MGB 7 warned people against entering the restricted area to visit or film the sinkhole and urged the public to rely on official advisories rather than unverified social media claims.
The bureau said it will continue assisting the City Government as monitoring continues. / DPC