Report on Mayon (Philippines) — September 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 9 (September 1988)
Managing Editor: Lindsay McClelland.
Mayon (Philippines) Crater glow; new areas of steaming
Please cite this report as:
Global Volcanism Program, 1988. Report on Mayon (Philippines) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 13:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198809-273030.
13.257°N, 123.685°E; summit elev. 2462 m
All times are local (unless otherwise noted)
Faint crater glow was observed at Mayon almost nightly during September. White steam emission, occasionally accompanied by bluish fumes, remained moderate, occupying 1/2 of the vent area. When PHIVOLCS volcanologists climbed the volcano on 8 September, the crater was 40-50 m deep and new areas of steaming had developed near the summit. A temperature of 285°C was measured at one of several fumaroles. Strong static charges at the summit caused hair to stand on end. On 29 September, a mudflow with a velocity of 2.3 m/s traveled down Basud gully, along the volcano's SE slope.
During September, 36 high-frequency and 31 low-frequency earthquakes were recorded plus 129 low-frequency and 16 high-frequency tremor episodes. From 1 to 9 October, 19 high-frequency and seven low-frequency earthquakes were detected in addition to 71 harmonic tremor episodes.
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.
Information Contacts: PHIVOLCS.