Report on Mayon (Philippines) — 1 May-7 May 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 1 May-7 May 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Mayon (Philippines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 May-7 May 2013. 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 a small phreatic eruption from Mayon occurred at 0800 on 7 May and lasted for 2 minutes and 26 seconds. A gray-to-brown ash cloud rose 500 m above the crater and drifted WSW. Ash fell in areas WNW, affecting the barangays of Muladbucad (10 km WSW), Guinobatan (11 km SW), Nabonton (10 km W), Nasisi (11 km W), Basag (10 km W), Tambo, Ligao City (19 km WSW), Albay (19 km SW), and areas upslope of these barangays. One rockfall was detected. Seismicity and gas emissions remained within background levels and indicated no intensification of activity. The Alert Level remained at 0 and the public was reminded not to enter the 6-km-radius Permanent Danger Zone (PDZ).
According to a news article, the eruption ejected large "room-sized rocks" towards about 30 climbers, killing five and injuring eight.
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.