Space agency: Mayon ashfall covers area half the size of Quezon City

MANILA, Philippines — Satellite data analyzed by the Philippine Space Agency showed that ashfall from Mayon Volcano has covered at least 8,544 hectares in Albay, an area roughly half the size of Quezon City.

According to PhilSA’s May 4 report, the ashfall was emitted by Mayon Volcano and detected through satellite imagery.

“For comparison, this area is around half the size of Quezon City,” the report read.

PhilSA said the full scope of Mayon’s ashfall was estimated by projecting data from visible areas to areas hidden by clouds.

The agency said the satellite-derived maps were aligned with atmospheric modeling, but stressed that verification on ground is still needed.

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

To identify areas affected by ashfall, the agency analyzed satellite images taken before and after the event, comparing data from April 28 and May 4 to detect physical changes on the ground.

Mayon activity

State seismologists first observed minor strombolian activity at Mayon Volcano on May 1.

The activity, which took place at the summit crater, produced ash plumes that rose about 100 meters before being carried west-southwest.

The Office of Civil Defense reported that the event affected 52 barangays across Camalig, Guinobatan and Legazpi City.