Report on Mayon (Philippines) — 16 August-22 August 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 16 August-22 August 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Mayon (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 16 August-22 August 2006. 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 explosions from Mayon continued during 16-19 August. On 17 August, ash-and-steam plumes drifted at least 5.3 km NE and reached the town Calbayog, where light ashfall was reported. Lava extrusion and collapsing lava-flow fronts that produced blocks and small fragments on the SE slopes continued during the reporting period. On 18 August, the Mibinit/Bonga valley lava flows reached ~6.8 km SE from the summit. The following day, PHIVOLCS estimated that the volume of erupted volcanic deposits was 36 to 41 million cubic meters.
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.