Mindanao earthquake update

Sarangani Earthquake Aftershock Watch: June 12–13 Update as Sequence Crosses 3,860 Events

A magnitude 5.3 aftershock struck west of Glan on June 13, initially reported by PHIVOLCS at magnitude 5.7 before being revised hours later. Five days after the June 8 mainshock, General Santos City remains under a state of calamity while rescue and recovery operations continue across southern Mindanao.

Sarangani Earthquake Aftershock Watch: June 12–13 Update as Sequence Crosses 3,860 Events image

Quick Answer

The strongest aftershock on June 13 struck at 10:05 a.m., about 30 kilometers west of Glan at 17 kilometers depth. PHIVOLCS first reported it at magnitude 5.7 before revising to 5.3. USGS measured it at 5.2. As of June 13, 61 people were confirmed dead, 33 missing, and 1,221 injured. The aftershock sequence had crossed 3,860 total events at that point. These figures have since been updated. See the June 15 watch article or the latest NDRRMC reports for current numbers.

Key takeaways

  • General Santos City and nearby areas in Sarangani and South Cotabato felt Intensity IV from the June 13 morning aftershock.
  • More than 30,000 homes were damaged and over 5,000 completely destroyed. About 4.13 million people felt strong shaking during the June 8 mainshock.
  • The aftershock sequence kept going well past June 13. By June 15, PHIVOLCS had logged 6,058 total events. A magnitude 5.5 aftershock struck on the night of June 15. The death toll was later updated to 68 as of June 16 per NDRRMC.

Frequently Asked Questions

Why did PHIVOLCS revise the June 13 magnitude?

After processing more station data, PHIVOLCS dropped the figure from 5.7 to 5.3, adjusted the depth from 10 to 17 kilometers, and moved the epicenter west of Glan rather than near Balut Island. This kind of revision is normal within hours of an event.

Why do PHIVOLCS and USGS show different magnitudes?

They use different seismic networks and calculation methods. Small differences between the two are common and expected.

What aftershocks hit on June 13 and where were they felt?

A magnitude 4.8 at 1:58 a.m., about 64 kilometers southwest of Maasim, was felt at Intensity II in Kiamba. The 10:05 a.m. event was felt at Intensity IV in General Santos City, Alabel, Kiamba, Maasim, Malapatan, Malungon, Polomolok, Tboli, and Tupi.

Damage and Access

Ten of Glan's 31 barangays are still cut off. In Barangay Kaltuad, landslides buried homes and blocked roads. Residents there have contaminated water and no heavy equipment. Emergency teams in some remote areas ran out of generator fuel within the first two to three days and lost communications when people needed them most. About half of Jose Abad Santos still cannot be reached by land. The coastal uplift also changed the shoreline in Glan and Jose Abad Santos, leaving reefs and seabed permanently above sea level in some areas.

Safety Reminders

Move to higher ground after any strong aftershock near slopes or the coast. Do not wait for an official tsunami warning because local waves can arrive faster than alerts.

For updates, go to PHIVOLCS at phivolcs.dost.gov.ph and NDRRMC at ndrrmc.gov.ph. If PHIVOLCS is down, GMA News and Inquirer are relaying official bulletins. Verify before sharing on social media.