Activity at Taal

[bjdeming]

It doesn't look extreme yet, though voggy:



Per PAGASA, the atmosphere is active through about 6-7 hours ago anyway.

 

[bjdeming]

From PHIVOLCS today (with PAGASA still showing active weather, using the Manila and Tagaytay lines):

 

[bjdeming]

PHIVOLCS reported a steam-driven blast out at Volcano Island and some tremor on the seismographs.

Afterwards Marlon Abuyo did a video from shore that he uploaded about eleven hours ago -- narration is in Tagalog but the recording shows continued strong vog though not quite as intense as what GMA noted Friday.



At least there is some air movement going on.

Wonder how vegetation as well as people are doing as time goes on at these high levels, though.

 

[bjdeming]

Less than 3,000 tonnes of SO2 measured on the 10th, per PHIVOLCS, but this was uploaded eight hours ago (Tagalog):



Their written article in English (mostly).

The PAGASA page reports light to moderate easterlies, though no wind direction at all for Metro Manila (about 40 miles from Taal), and no mention of the monsoon.

Glad Taal's emission has dropped in these conditions but that atmosphere has been polluted for a while now, and perhaps there hasn't been much ventilation overall.

 

[bjdeming]

I m seeing no recent news come up in an online search, but it is apparently bad enough still for Marlon Abuyo to stay in his car when he did a livestream yesterday (the rain factored into it, too, of course, but there is also no activity along the shore and I think there would at least be some fish farmers working on the quay and out there on the water -- no matter what the weather, income is income):



PHIVOLCS still reports vog.

Taal's SO2 output in that bulletin is slightly increased from some previous lowered levels after the big emission, but it is well within four digits: huge for many dormant volcanoes (and for current atmospheric conditions ) but low for this one.

There is seismicity, too, but alert level remains at 1 out of 4 and PHIVOLCS isn't reporting any potential short-term eruption concerns.

 

[bjdeming]

Well, the air is in motion, anyway, and it is Taal in full moonlight:

 

[bjdeming]

Low-level steam-driven phreatic eruptive activity at Taal reported today, but PHIVOLCS keeps the alert at Level 1.

There are images at the link, but not much on YouTube. I don't think this following video is of the same event but it was uploaded today and spans the caldera (the distant hills are part of the caldera rim, as is the hill this resort is on).

Taal is big, but the caldera doesn't go off very often.

That passive plume from Main Crater's lake on Taal Volcano Island (which is where all historical eruptions have occurred) happens quite often. "Phreatic" usually means some explosiveness.

Nice clear view, too.



(And some of the tilapia fish in those rectangular fish farms in the lake likely will end up in your grocery's fish section!)

 

[bjdeming]

From PHIVOLCS today:

TAAL VOLCANO ADVISORY

1 October 2024

6:50 PM



This is a notice of weak phreatic activity at Taal Volcano.



Five (5) weak phreatic or steam-driven events at the Taal Main Crater occurred today, 01 October 2024, between 01:10 AM and 04:37 PM and lasted between two (2) to six (6) minutes based on visual, seismic and infrasound records of the Taal Volcano Network (TVN). The events produced steam-laden plumes that rose 300 to 2100 meters above the Main Crater before drifting east-northeast based on IP camera monitors. A total of seventeen (17) of these events have been recorded since 22 September 2024. Meanwhile, sulfur dioxide (SO2) emissions averaged 1,354 tonnes/day on 30 September 2024. Nonetheless, average SO2 emissions since January this year remain high at 6,760 tonnes/day. Weak phreatic activity is likely driven by the continued emission of hot volcanic gases at the Taal Main Crater and could be succeeded by similar events. The background levels of volcanic earthquake activity and ground deformation detected at Taal indicate that unrest is unlikely to progress into magmatic eruption...

 

[bjdeming]

PS: Saw a Reuters article on this that called Taal "one of the smallest volcanoes" to have big eruptions. Once again, Taal is not small. It is a big hole in southern Luzon (image by NASA via Wikipedia) --

-- see those erosion lines around Lake Taal? They mark Taal Caldera's outer rim (it used to be open to the sea at the lower left until a big eruption from the island in the 1700s closed off the bay, which then became a freshwater lake).

During human history Taal just happens to have had a particularly active resurgent central caldera structure, known as Taal Volcano Island, that has 40-some vents, a few of which are cones resembling small volcanoes.

TVI is deadly but it is only a small part of Taal, which resurfaces whole provinces when it erupts -- nothing like that is on the way in our lifetime, from everything I've read, and the last caldera eruption was hundreds of centuries ago.

It's not unusual that moderately large eruptions come out of the small TVI vents -- those eruptions have roots in big Taal Volcano (I think 2020 was an explosion of the local hydrothermal field).

 

[bjdeming]

Taal is still fussing. In their activity report through October 1, the GVP noted, among other things, "PHIVOLCS concluded that the event was likely driven by water contacting a small body of shallow magma that has been steadily degassing for the previous three years; deformation and seismic data were at background levels and did not indicated that the unrest would escalate into a large magmatic eruption."

 

[bjdeming]

Taal is still having phreatic blasts that look quite impressive -- note, too, in thermal imagery, the main crater lake bubbling like a pot on the stove:




Per GVP through October 8:

Taal​

Philippines​

14.0106°N, 120.9975°E; summit elev. 311 m​

All times are local (unless otherwise noted)​

Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued advisories for Taal reporting that a total of 30 phreatic events were recorded almost daily during 22 September-5 October. Five phreatic events during the morning of 5 October were recorded by the seismic network. A minor phreatomagmatic eruption began at 1132 and lasted four minutes based on visual observations and seismic and infrasound data. The eruption ejected a short, black plume followed by a steam-rich plume that rose 2 km above the crater rim and drifted SW. Trace ashfall was reported in Agoncillo, Batangas, W of Taal Lake. Sulfur dioxide emissions averaged 2,068 tonnes per day (t/d) during 5-6 October and 1,267 t/d on 7 October, remaining at elevated levels. One small phreatic event was recorded during 6-7 October, and two phreatic events lasting 1-4 minutes long were recorded during 7-8 October. Hot fluids upwelling in the lake were observed during 5-8 October along with emissions that rose 900 m above the crater rim and drifted SW. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain prohibited.

Geological Summary. Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities.

[Layperson speculation] At the moment, this form of pressure release seems to be adequate, but again, if the caprock over the hydrothermal field fails, we might see another 2020-style explosive round, this layperson suspects.

That had some lava fountaining but no widespread lava eruption as in some past eruptions -- and PHIVOLCS doesn't expect it now.[/Layperson speculation]

Reportedly there's smog in Manila today but it isn't believed to come from Taal.

 

[bjdeming]

No changes in the October 11 update, except for vog (perhaps due to the atmospheric conditions causing smog in nearby Manila, this layperson guesses -- Taal's SO2 output, while high, is nowhere near its five-digit occasional peaks).

This is just a neatly framed overview of the whole situation to date:

 

[bjdeming]

It's so easy to leave volcano posts hanging at the crisis point. Just for closure, Taal quieted down and PHIVOLCS has reported only a few bursts since that episode. See their current bulletin for Taal's status below. Four-digit SO2 emission is large for any volcano, but it's a lot better than the five-digit count here now and then.

 

[bjdeming]

Now Taal is too quiet. Per the Manila Bulletin, PHIVOLCS is telling everyone that the lack of earthquakes recently -- there's usually always a few, given the hydrothermal field and various shifts in magmatic fluids -- does NOT mean that Taal is inactive, and among other things, they are asking aircraft not to fly over it.

The thing about alert systems is that they are based on activity, which is good, but they also are limited by the "pressure-cooker" aspects of volcanoes and the inability of monitoring to accurately see, through miles of rock, physical and chemical processes that don't cause any signals but very much can cause sudden eruptions, blasts, groundmass movements, etc , at the surface.

When Taal went off big time a few years ago, PHIVOLCS cycled from Level 1 up to the highest in less than an hour. There was little else they could do.

Volcano monitoring is top-notch in many parts of the world, but even here in the US, it is still very much a work in progress.

 

[bjdeming]

It's back in business at the same low-level alert:

 

[bjdeming]

Taal quieted down, as usual. Now it's getting a little shaky but the SO2, though on the rise, is still only four digits. Phivolcs has it at Level 1