Balut Island and Glan Earthquakes: Mw 5.1 & Mw 5.0

Two Earthquakes Near Balut Island on October 28: Mw 5.1 and Mw 5.0 Confirmed

October 28, 2026

4–6 minutes

Quick Facts

Parameter	Details
Event 1	Mw 5.1 · 7:43:47 a.m. · 21 km northwest of Balut Island, Davao Occidental · 18 km deep
Event 2	Mw 5.0 · 9:11:53 a.m. · 23 km S 29° E of Glan, Sarangani · 18 km deep
Highest reported intensity	III (Mw 5.1); IV in Sarangani, Davao Occidental (Mw 5.0)
Highest instrumental intensity	IV for both events
Official assessment	No damage or further aftershocks expected from either event
Source	PHIVOLCS Bulletin No. 2 for each earthquake

What Happened?

PHIVOLCS recorded two tectonic earthquakes near southern Mindanao on October 28, 2026. Both were classified as aftershocks of the June 2026 Mw 7.8 offshore Sarangani and Mw 6.5 offshore Davao Occidental earthquakes.

The first, Mw 5.1 at 7:43:47 a.m., was located 21 kilometers northwest of Balut Island, Davao Occidental, at 18 kilometers depth. Its maximum reported intensity was III and maximum instrumental intensity IV.

The second, Mw 5.0 at 9:11:53 a.m., was located 23 kilometers south 29 degrees east of Glan, Sarangani, also at 18 kilometers depth. Reported Intensity IV was recorded in Sarangani, Davao Occidental; Intensity III included General Santos City, Glan, Alabel, Malungon, Kiamba and Tupi. Its maximum instrumental intensity was IV.

PHIVOLCS expected no damage and no further aftershocks from either individual event. The two earthquakes occurred close together in time, but their bulletins do not establish that one caused the other.

Official Assessment

Both earthquakes belong to the previously identified June 2026 aftershock sequence. An assessment of no further aftershocks from these individual events does not mean that the wider sequence has ended. Follow subsequent PHIVOLCS bulletins for revisions.

Infographic instructions for earthquake safety: 'Drop, Cover, and Hold.' Steps include dropping to hands and knees, taking cover under a sturdy table or desk, and holding tight until shaking stops. Warnings about staying away from windows, mirrors, and heavy objects.

AI-Assisted Content Disclosure:

The information below was generated with the assistance of artificial intelligence and is provided for general informational and educational purposes only. While every effort has been made to ensure accuracy and clarity, AI-generated content may contain errors, omissions, or interpretations that do not reflect the latest scientific findings or official guidance.

This content should not be considered a definitive or authoritative source for earthquake-related information. Readers are encouraged to verify important details with official agencies such as PHIVOLCS, the Office of Civil Defense (OCD), and other relevant government or scientific institutions before making decisions or taking action.

Always rely on official advisories during emergencies and disaster situations.

Infographic explaining seismic event magnitudes and their potential impacts, categorized from below 3.0 (very small) to 8.0+ (great), detailing effects and damage levels.

Why Did These Earthquakes Happen?

Aftershocks can occur as the crust adjusts following a larger tectonic earthquake. PHIVOLCS links both October 28 events to the June 2026 offshore Sarangani–Davao Occidental sequence.

Is There a Tsunami Threat?

Neither Bulletin No. 2 includes tsunami guidance. This should not be interpreted as an explicit declaration of no tsunami threat. Coastal residents should follow separate official PHIVOLCS tsunami advisories when issued.

Could Aftershocks Occur?

PHIVOLCS assessed no further aftershocks expected from either individual October 28 event. This does not rule out future seismic activity in the wider region.

Safety Advice

If you felt either earthquake, check your surroundings for hazards, avoid damaged structures and follow PHIVOLCS and local disaster authority updates. Review the preparedness guidance below.

If you felt the earthquake:

Remain alert and monitor PHIVOLCS for any subsequent earthquake bulletins. For context on the broader June 2026 earthquake sequence, you may also want to review WVF’s earlier coverage of aftershocks in Davao Occidental for additional context on how a sequence can continue after a larger event.
Stay away from visibly damaged buildings and structures. If you are in a high-rise, use a controlled evacuation rather than rushing into stairwells; see High-Rise Earthquake Evacuation, Part 2: Thirty Floors Down to Safety.
Check your home for hazards such as gas leaks or damaged electrical wiring. Visit our blog, Ideas to Secure Your House Against Earthquakes: Simple Steps for Safety in the Philippines for ideas on securing your house.
Monitor only official information from PHIVOLCS and local disaster authorities.
Avoid sharing unverified information on social media.
Remember to Drop, Cover, and Hold On if another strong earthquake occurs. If you are in a high-rise or workplace setting, review WVF’s High-Rise Earthquake Evacuation before deciding when and how to move after the shaking stops.

TAKE THE NEXT STEP

Don’t Just Read About Earthquakes—Prepare for Them.

Even when a specific earthquake is not expected to cause damage or aftershocks, it is a useful reminder to prepare before the next damaging event. Choose the next step that best fits your household.

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