Report on Mayon (Philippines) — February 1978
Scientific Event Alert Network Bulletin, vol. 3, no. 2 (February 1978)
Managing Editor: David Squires.
Mayon (Philippines) Glow and harmonic tremor continue
Please cite this report as:
Global Volcanism Program, 1978. Report on Mayon (Philippines) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 3:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197802-273030.
13.257°N, 123.685°E; summit elev. 2462 m
All times are local (unless otherwise noted)
"Crater glow at the summit, observed on 6 November, was followed by increased volcanic tremor 2 days later. Aerial investigations disclosed bluish fumes in the SW portion of the crater. At 0116 on 12 November an imperceptible volcanic earthquake with a rather large double amplitude was recorded, lasting more than one minute. Drying of vegetation on the upper flank (about 1,700 m elevation) was noted on 18 November. On 22 December, 13 large-amplitude volcanic tremors were recorded, accompanied by increased steam emission forming a cauliflower-shaped cloud. Glow, accompanied by volcanic tremor, was continuing as of late January."
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: G. Andal, COMVOL, Quezon City.