Mayon eruption update for 12/16/2009

Lava on Mayon, December 2009, with Legazpi City in the foreground.

The mainstream media has picked up on the activity at Mayon – I’ve seen it splashed across CNN, FoxNews, ABC, BBC and others. Most of the coverage has been decent, however, I do worry when I see that people have found Eruptions using search terms like “Mayon supervolcano”. I think that is when we worry that the made-for-TV word like “supervolcano” has gotten a little overused, when people worry every volcanic eruption might be a “supervolcano.”

On to the update!

Explosions have continued unabated at Mayon, with the explosive plume reaching 500 m / 1600 feet – which is small fry in the realms of ash plumes, but indicates that the volcano might still be “clearing its throat” as it were. Renato Solidum of PHIVOLCS gave this warning: “There is the possibility that it can turn into the explosive phase of the eruption”, which I would assume he means a true Plinian phase. The continuing explosions, lava extrusion (see video below) and high levels of seismicity mean that the evacuations for the area will continue. Almost 30,000 people have already been moved.

The BBC posted some video of the eruption and from that, it looks pretty clear to me that the lava flow isn’t as much low viscosity flows as crumbling, glowing dome rock. You can see the tumbling chunks of lava rolling down the mountain – an event like this is like to produce a lot of hot “block-and-ash” flow deposits with plenty of breadcrust bombs.