PhilSA: Mayon ashfall covers area half of the size of QC

Ashfall from the Mayon Volcano has covered an area in Albay roughly half the size of Quezon City, the Philippine Space Agency (PhilSA) reported on Tuesday.

“Based on the analysis, at least 8,544 hectares (~85,440 sqkm) were covered by ashfall. For comparison, this area is around half the size of Quezon City,” PhilSA said in a statement.

The ash deposits were classified using change detection on a Sentinel-2 satellite image from May 4, 2026 in comparison with the image taken before the event on April 28, 2026.

“For areas obstructed by cloud cover, ash deposit cannot be directly determined,” PhilSA said.

It added that the projected ash deposit extent is based on delineating a region around areas classified to have ash deposits.

“These results are consistent with projections from atmospheric trajectory modeling and reports from the ground. The map is still subject to ground validation,” PhilSA said.

On Friday, May 1, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) recorded minor strombolian activity at the Mayon Volcano.

The event occurred at the summit crater around 2:41 a.m. and generated ash plumes approximately 100 meters above the crater before drifting west-southwest.

This affected at least 52 barangays in 52 barangays in Camalig, Guinobatan, and Legazpi City, according to the Office of Civil Defense (OCD). — JMA, GMA News