PHIVOLCS reported that during 13-20 March activity at Mayon was mostly characterized by periods of gravity-driven lava advancement, gas-and-steam emissions, rockfalls, and quiescence.
Lava flows extended 3.3 km, 4.5 km, and 1.9 km long in the Mi-isi (S), Bonga (SE), and Basud (E) drainages, respectively.
Sulfur dioxide emissions were between 969 and 2,077 tonnes/day.
Steam-and-gas emissions drifted SW.
An episode of lava fountaining was recorded during 0831-0832 on 14 March and produced a light-gray ash plume that rose 200 m above the crater and drifted SW.
At 1347 on 16 March a pyroclastic flow traveled 4-5 km down the Mi-isi and Basud drainages.
The Alert Level remained at 3 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)