Volcano thread

[bjdeming]

Meanwhile, in Costa Rica...



GVP page on Poas.

Here's another cool view:



Not one brake light!

 

[bjdeming]

Per KVERT:

...

The strong explosive eruption of the Bezymianny volcano began at 23:10 UTC on 23 April. The ash cloud 36x26 km in size continues to move to the north-northeast of the volcano. KVERT continues to monitor the Bezymianny volcano. An explosive eruption of the volcano continues. The danger of ash explosions up to 15 km (49,200 ft) a.s.l. remains. Ongoing activity could affect international and low-flying aircraft.
(12) Volcanic cloud height:	10000-11000 m (32800-36080 ft) AMSL Time and method of ash plume/cloud height determination: 20250423/2310Z – Himawari-9 14m15
(13) Other volcanic cloud information:	Distance of ash plume/cloud of the volcano: 32 km (20 mi) Direction of drift of ash plume/cloud of the volcano: NNE / azimuth 25 deg Time and method of ash plume/cloud determination: 20250423/2310Z – Himawari-9 14m15

A look at the webcams shows nothing but what looks like ice and/or snow right now.

Current Tokyo VAAC advisory reports ash to 36,000 feet.

At relatively blind times like these, I'm glad Bezymianny is so remote (and that there isn't much air traffic to Russia from the West these days). The villages are far enough away to be okay, plus residents are volcano savvy in all seasons.

 

[bjdeming]

Conditions are not completely cloud-covered, per this satellite image from 2320Z, ten minutes into the eruption:

 

[bjdeming]

Well, good:

...
The strong explosive eruption of the Bezymianny volcano began at 23:10 UTC on 23 April, and ended about 03:00 UTC on 24 April. The explosions sent ash up to 11 km a.s.l., and ash plume extended for about 232 km from the volcano. Ashfalls were noted at Atlasovo, Lazo, Milkovo Villages. At now, no ash explosions observed at the volcano, but a large ash cloud 110x175 km in size continues to move to the southwest of the volcano. Ash cloud was noted at 7-7,5 km a.s.l., in the distance about 320 km of the volcano at 05:10 UTC on 24 April. KVERT continues to monitor the Bezymianny volcano.

The activity of the volcano continues. Ongoing activity could affect international and low-flying air craft.

That's dated about half an hour ago.

The initial cloud was sizable but responded to prevailing winds, i.e., it wasn't plinian as this layperson understands the term -- also, because it was a blast, not a sustained eruption.

We'll have to wait and see what Bezymianny does next.

If anyone is in the mood for "plinian Kamchatka," sources I've read call these 1975 lava fountains at nearby Plosky Tolbachik subplinian, which is not something lava fountains typically do (outside of something like an Icelandic flood lava eruption, as in 1783's Laki disaster).

This Soviet-era film is in Russian, but the volcano views are awesome and, for lagniappe, there's a happy dog:

 

[bjdeming]

USA! USA! Cold War era -- gotta have an inside look at US volcanologists at work. Best book: Volcano Cowboys, and Mount St.Helens, 1980.

But this is the best video documentary I've seen, at Pinatubo in 1991:

 

[bjdeming]

Kamchatka update -- Yep, the whole thing as of April 24 from KVERT.

These updates on their erupting volcanoes are routine. Apparently Bezymianny simply went back into its effusive (lava) phase after the blasts this week, so those weren't the final events of this cycle.

CIRA includes Sheveluch in the Klyuchevskoy group (though I'm not sure that geoscientists trying to figure out what's going on underground do), and it eventually will make international headlines again some day, so here's its Global Volcanism Program page.

 

[bjdeming]

Meanwhile, on the other side of the Bering Strait...



Here's more info on Atka.

 

[bjdeming]

Bulusan in the Philippines has erupted, as it does frequently at VEI 1 and 2 intensity levels, per the Global Volcanism Program.

Reading that it's on the Irosin Caldera rim made me wonder what else might be going on there.

Not much, apparently. There is little info found in a quick online search on this caldera, which doesn't sound like one of the clearly outlined ones, and the LaMEVE database lists its VEI 6 formation some 41,000 years ago to Bulusan.

According to the abstract of this paper, the caldera-forming eruption might have happened this way (ignimbrite is voluminous pyroclastic flow deposits):

...During the precursory eruption, fine ash was ejected, and a small lava dome, Malobago, was extruded on the southeastern slopes of the present caldera outline. Other similar lava extrusion may have occurred within the caldera.

　　After a geologically short pause (likely within 10 years）, the main caldera-forming eruption, which consisted of three distinct eruption phases, started. The first phase involved a plinian eruption, likely within the present caldera, resulting in the northward emplacement of pumiceous tephra with bulk volume of 20km3. Partial collapse of the plinian column repeatedly occurred during the early stage of the plinian phase. These formed intra-plinian flow deposits, which are generally thin, fine grained, and associated with fallout pumice layers. A strong ground shaking occurred in the Sorsogon area during the waning stage of the plinian phase, resulting in the formation of disturbed structures both at the base and in the upper horizon of the plinian deposit.

　　This was followed by the generation of the lower Irosin ignimbrite with associated ground layers. The final eruption was catastrophic, forming the present caldera topography and emplacing the upper Irosin ignimbrite...

It's quite likely that something that large -- at any monitored volcano -- would have correspondingly large pre-eruption signals (ground deformation, increased outgassing, ground and water temperature changes, etc.).

PHIVOLCS would pick up the larger precursors and say so. They have Bulusan so carefully monitored that they saw this current and typically mild eruption coming.

Here are a couple of videos uploaded over the last four hours or so:




This one is ABS-CBN coverage and in Filipino, but there are some views of the volcano:

 

[bjdeming]

Meanwhile, in the US, Yellowstone seems to be doing exactly what we'd like it to do:

...
“Although we detected a volatile-rich layer, its bubble and melt contents are below the levels typically associated with imminent eruption,” Schmandt said. “Instead, it looks like the system is efficiently venting gas through cracks and channels between mineral crystals, which makes sense to me given Yellowstone’s abundant hydrothermal features emitting magmatic gases.”

Schmandt likened the system to “steady breathing” with bubbles rising and releasing through the porous rock — a natural pressure-release valve that lowers eruption risk...

-- Source

 

[bjdeming]

Here's a picture of the truck they used to create seismic waves in the Yellowstone study, and a link to more info:

 

[bjdeming]

It sleeps now, but when Hekla awakens it is mean.



Link will be in Icelandic.

 

[andyhb]

Massive lava fountains at Kilauea right now, must watch:

 

[bjdeming]

Massive lava fountains at Kilauea right now, must watch:

It didn't last long, but they were gorgeous!

 

[bjdeming]

Every year on June 3rd, locals remember the tragedy at Unzen, on the Shimabara Peninsula, Kyushu, Japan, in 1991, which killed Katia and Maurice Krafft, Harry Glicken, and 40 taxi drivers, police/firefighters, and journalists who had all followed the volcanologists into the exclusion zone.

This NHK coverage has video that probably won't work with autotranslation so that's the original URL.

The killer pyroclastic flow was unusually mobile and went over a ridge that stood between the dome and the people.

The exclusion zone took that possibility into account. The volcanologists, who were after pyroclastic-flow footage for a public safety film, did not.

Just don't go into exclusion zones around a volcano, no matter how quiet things seem!

 

[bjdeming]

Fuego, near Guatemala City, seems to be very active today:



Most recent GVP report:

Most Recent Weekly Report: 28 May-3 June 2025​

The Instituto Nacional de Sismología, Vulcanologia, Meteorologia e Hidrología (INSIVUMEH) reported continued eruptive activity at Fuego during 27 May-3 June. Daily explosions were recorded by the seismic network at rates of 3-7 per hour when reported. The explosions generated daily gas-and-ash plumes that rose as high as 1.1 km above the summit and drifted as far as 30 km NW, W, and SW. Incandescent material was occasionally observed at night being ejected 100-150 m above the summit. Rumbling sounds and shock waves were occasionally reported. Explosions sometimes generated block avalanches that descended multiple flanks, sometimes reaching vegetated areas. Ashfall was reported in Panimache I and II (8 km SW), Morelia (10 km SW), Santa Sofia (12 km SW), El Porvenir (11 km SW), Finca la Asunción (12 km SW), and surrounding areas during 27-28 May and in areas downwind including Panimache I and II and Yepocapa (8 km WNW) during 1-2 June."

As I understand this special report --



-- Fuego's typically rather weak explosive activity switched today into very intense effusive (lava flow) activity, and the volcano currently sounds like a jet engine or train.

Pyroclastic flows are part of this increased activity.

Here's a cam, but the current weather is affecting visibility:



INSIVUMEHs website is very slow but that Twitter account is official, apparently (I just found it today), and is updating frequently.

Edit: Here's INSIVUMEH's bulletin page (slow loading).

 

[bjdeming]

X translation: "The lava flow began to appear around 2 p.m.This image from @prensa_libre shows one of the lava domes at risk of collapsing at any moment. If a pyroclastic flow were imminent, its magnitude could vary."

Fuego is that volcano which sent a deadly flow into a neighborhood a few years ago. I know nothing yet about the areas at risk from this new change in behavior.

 

[bjdeming]

Huh. That happened on June 3rd, 2018. They have some images of it in the thread, apparently posted before today's lava flow activity began.



People around Fuego tonight must feel like they're reliving a nightmare. Hopefully they will be okay. The SISNA GT account posts that they will update news over the early morning hours if needed.

 

[bjdeming]

This is a good account to follow for Guatemalan volcanoes. Watching it live, though the weather clouds blur everything, it looks like big fountains are going up there now.



At 1 a.m. on a dark rainy week night. Oh, I hope people are out from danger.

 

[bjdeming]

Weather clouds are thickening, so here are some screenshots from the last couple of hours:

<Layperson speculation> This is still dangerous but not in an explosive 2018 kind of way since the lava is "runny" -- it doesn't hold in the gases until shattering pressure blows up in a big pyroclastic flow. It releases them in fountains.

There can still be smaller flows, as well as lahars, especially in this weather. I hope the people are okay. Also, SISNA GT mentioned a lava dome -- if that collapsed or exploded, that could cause a sizable flow, too. Thus far, I've seen no new tweets from them. </layperson speculation>

 

[bjdeming]

Fuego this morning:



To sum up the news I could find right now, some moderate to large pyroclastic flows occurred this morning in several canyons (<layperson speculation> probably column collapse </layperson speculation>), but not 2018 style, rather, more typical of an active Fuego phase -- one of the canyons is named Ash (Ceniza)!

In 2018, some people stood and watched the flow that would kill them approach because they were used to these more typical flows, which only run out a few miles at most.

Only about 300 people have been evacuated, reportedly, but the road between Guatemala City and another major city/tourist attraction, Antigua, is closed, and in the last hour some big lahars are occurring -- imagine a river in flood; now imagine the floodwater to be wet concrete (or maybe a little more dilute).

Just one of them:



Also, pyroclastic flows continue: