Activity at Taal

[MNTornadoGuy]

Taal has been displaying increasing activity recently with very high SO2 emissions (that peaked at 23,576 tons/day on Oct 16), and 1-3 km tall steam plumes. There has been some volcanic tremors and inflation too.
https://www.phivolcs.dost.gov.ph/in...taal-volcano-bulletin-19-october-2021-8-00-am

 

[bjdeming]

Yes, but they're still keeping it at Level 2, just as it has been for months. Hope it stays that way!

 

[bjdeming]

No changes; just thought an update would be good. Volcanic "severe weather," i.e., elevated alert status (when the volcano is known--the most dangerous ones are those that aren't), doesn't pass quickly.

Just for comparison, La Palma's erupting volcano, MUCH smaller, was putting out 50,000 tonnes of sulfur daily at first, and it sometimes gets up in that high end of the range still, though I think the eruption might be winding down.

Gas emissions are a sign there's magma degassing near the surface, but the volume of sulfur, etc., depends mostly on that magma's chemistry. The telltale warning signs of impending trouble are more likely to be ground deformation (Taal is deflating, per PHIVOLCS) and seismicity (high at Taal but within normal limits for Level 2, per PHIVOLCS).

I'm still amazed that so much lake water burbled down into Taal's hydrothermal system after the 2020 blast, yet nothing explosive happened.

BTW, the lake in the nice picture at that link fills most of Taal Caldera; it's huge. The active part right now is the central vent complex called Volcano Island. It used to host one of the very few, perhaps the only, crater lake within a crater lake (the caldera's). Maybe another one has formed.

PHIVOLCS was watching that crater lake on Volcano Island when the January 2020 eruption began:



There's video online that purports to show it, but anything taken with a hand camera close to the lake and showing a plume isn't Taal's 2020 biggy. Both camera and photographer would have probably been vaporized (happened to a couple of hapless volcanologists near the cone of Galeras, Columbia, in 1991).

 

[bjdeming]

Speak of the devil, Taal had a short steam-driven blast Monday night (guess it's Tuesday over there now), per PHIVOLCS.

Also, there were two errors in that last post:

1. Volcano Island began inflating again in August. Level 2 is maintained, though.
2. That tragedy in Colombia happened in 1993, not 1991. I haven't read the book about it in a while and only got back into it today.

 

[bjdeming]

Two more steam-driven small eruptions. Still Level 2.

 

[bjdeming]

Per the Smithsonian's Global Volcanism Program report this week:

PHIVOLCS reported that unrest at Taal continued during 17-23 November. Sulfur dioxide emissions continued to be elevated, averaging 6,643-12,168 tonnes/day. Upwelling hot volcanic fluids were visible in the crater lake, and daily gas-and-steam plumes rose 1-3 km above the lake and drifted WNW, WSW, and SW. Low-level background tremor persisted along with 5-30 volcanic earthquakes per day, 2-4 low-frequency volcanic earthquakes per day, and 1-23 daily episodes of volcanic tremor, each lasting 1-5 minutes. One hybrid earthquake was recorded during 19-20 November and three were detected during 22-23 November. No earthquakes were recorded for a period during 18-19 November. Three short (1-5 minutes) phreatomagmatic bursts were recorded at 0811, 0817, and 0834 on 22 November. The events generated plumes that rose 200-1,500 m based on thermal camera images. PHIVOLCS stated that the events were likely driven by fracturing and gas release from magma beneath the Taal Volcano Island. The Volcano Alert Level remained at a 2 (on a scale of 0-5). PHIVOLCS reminded the public that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ) and that boating on Taal Lake was prohibited.

 

[bjdeming]

Taal is having increased degassing this month, with almost 16,000 metric tons of SO2 yesterday and only slightly less today.

AFAIK there are no streaming cams, but here's a shot today of the gas plume rising from the crater lake on Volcano Island, which in turn is surrounded by the crater lake that fills Taal Caldera. (Might want to take some Dramamine before watching.)



Per PHIVOLCS, alert level is still 2 and the edifice continues to deflate.

 

[bjdeming]

Taal had a high SO2 emission for a while and then it dropped by almost half. I wondered if that might mean a blockage in the conduit, and now phreatomagmatic bursts are occurring.

They have raised the alert to 3 (5 is the highest) and ordered evacuations of most vulnerable areas nearby. SO2 in the latest bulletin, while respectable, is still low compared to peak days recently.

I'm so glad this guy is doing daily video. This was posted 8 hours ago:

 

[bjdeming]

A lot of "thousands flee" news stories out there, but it's just phreatomagmatic bursts. There is a magma intrusion reported at the main crater, but per this article PHIVOLCS doesn't see an upgrade to Level 4 coming any time soon.

It isn't mentioned in today's bulletin, but up until now, they have said the deflation that began in October has continued. That's the thing to look for, I think: a switch back to inflation of the edifice would be worrisome.

 

[bjdeming]

Taal has had on and off upticks in activity; I've followed some of it over the summer in a post that's currently pinned at my blog.

But 29 phreatomagmatic bursts, although weak, call for a heads-up.

PHIVOLCS hasn't raised the alert: the other parameters haven't changed with these bursts (it's been at Level 1 for a while, and the present inflation/deflation reported at the above link has been happening for a while, too).

But I learned just how dangerous Taal is, and how quickly its status can change, while revising the DV book (ongoing). This is something to keep an eye on -- things can happen fast here, if the caprock under Volcano Island and atop the hydrothermal system breaks.