Report on Mayon (Philippines) — 15 October-21 October 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 October-21 October 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Mayon (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 15 October-21 October 2014. Smithsonian Institution and US Geological Survey.
13.257°N, 123.685°E; summit elev. 2462 m
All times are local (unless otherwise noted)
PHIVOLCS reported that during 14-21 October white plumes rose from Mayon's crater and drifted NW, W, WSW, SW, and SE. On 14 October a seismic signal indicating a rockfall was recorded and a brief period of incandescence from the crater was observed. A few volcanic earthquakes were recorded during 18-21 October. On 19 October weak incandescence from the crater was noted. A new lava flow first observed that same day was 300-400 m long on 20 October based on an aerial survey. Weak crater incandescence from the lava dome was again seen on 21 October. The Alert Level remained at 3 (on a 0-5 scale).
Geologic Background. Beautifully symmetrical Mayon, which rises above the Albay Gulf NW of Legazpi City, is the Philippines' most active volcano. The structurally simple edifice has steep upper slopes averaging 35-40 degrees that are capped by a small summit crater. Historical eruptions date back to 1616 and range from Strombolian to basaltic Plinian, with cyclical activity beginning with basaltic eruptions, followed by longer term andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often devastated populated lowland areas. A violent eruption in 1814 killed more than 1,200 people and devastated several towns.