Friday Flotsam: Undersea volcanism revisited and a Mayon update

Finals day for me, so I’ll be grading grading grading … but first, a little news:

The May 2009 eruption of West Mata. Image courtesy of NSF and NOAA.

I covered it in May, but the popular press is now all over the West Mata undersea eruption – mostly thanks to the media boost that AGU can give you. It is worth checking out the new articles on the eruption in the Lau Basin near the Marianas, mostly because of the nifty video of the eruption. In the video, you can clearly see both an explosive component of the eruption as gas “burps” out through a cooled carapace and a more effusive pillow lava component coming down the right side of the vent. I’ve been scratching my head at exactly how you have explosive volcanism at 4,000 feet / 1,200 meters below the ocean surface – the pressure should be too high – but this lava must be full of volatiles to produce an eruption like this. There is tons of information on this eruption on the Vents Program website.

More lava, more ash, more signs of a bigger eruption at Mayon in the Philippines. The volcano is now racking up hundreds of earthquakes a day and PHIVOLCS is saying that a

“major eruption” could be coming in the next week

and may move the volcano up to Level 4 status. However, it hasn’t stopped people from already returning to their farms on the slopes of the volcano – which is leading to more forced evacuations and a curfew in Albay Province.