Report on Mayon (Philippines) — 13 June-19 June 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 June-19 June 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Mayon (Philippines). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 13 June-19 June 2001. Smithsonian Institution and US Geological Survey.
13.257°N, 123.685°E; summit elev. 2462 m
All times are local (unless otherwise noted)
A high level of high-frequency low-duration harmonic tremor was detected on Mayon that was associated with near-continuous detachment of hot rock fragments from the summit lava dome. In addition, moderate amounts of steam emanated from the crater, crater glow was fair-to-bright, and SO2 emission (average of ~2,700 metric tons per day) was well above the baseline value of 500 metric tons per day. Alert Level 3 remained in effect, prohibiting entry within the 6-km-radius permanent danger zone.
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.