MANILA - A "crater glow" has been observed at the Mayon Volcano in Albay on Friday, hours after the provincial government declared a state of calamity.
In the photo tweeted by Phivolcs, Mayon's crater glow, or "banaag" can be seen around the volcano's dome. The picture was captured around 7 p.m, it said.
"(Twenty-eight) relatively smaller rockfall events and zero volcanic earthquakes have been detected by the Mayon Volcano Network since 5:00 AM today," the seismology agency said.
Phivolcs said it observed 3 fast-moving avalanches of volcanic ash, rock and gases, known as pyroclastic density currents, on Mayon's slopes on Thursday.
It earlier placed the volcano under Alert Level 3, which meant "increased tendency towards hazardous eruption."
Thousands of residents around its 6-kilometer permanent danger zone and nearby areas have been evacuated, local officials said.