Report on Mayon (Philippines) — 6 February-12 February 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 February-12 February 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Mayon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 6 February-12 February 2002. Smithsonian Institution and US Geological Survey.
13.257°N, 123.685°E; summit elev. 2462 m
All times are local (unless otherwise noted)
A continuous decline in volcanic activity has occurred at Mayon since the volcano's Alert Level was reduced from 2 to 1 on 19 October 2001. On 5 February PHIVOLCS further decreased the Alert Level to 0 because all measured parameters had decreased. Incandescence, probably from still-hot residual magma beneath the crater, remained visible at the summit.
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.