MNTornadoGuy
Member
There appears to be quite a bit of inflation ongoing at La Palma with ~2 inches of vertical deformation.
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La Palma/Cumbre Vieja Volcano in the Canaries
- Thread starter bjdeming
- Start date
- Thread starter
- #82
That is at a single station close to the cone, per multiple reports, and from what I've read in the online news, it puzzles the experts enough to have made them pull personnel out of the area.
It's what the volcano spotters were talking about in that tweet up above.
Beside what IGN wrote in response, such things are expected near and in an eruptive zone. A new vent might even open up there. The important thing is that the rest of the island is quiet (other Canary Islands, BTW, like Tenerife, have their own volcanoes, separate from La Palma, and are all at baseline; the submarine volcano off the coast of El Hierro, an island that's a little west of La Palma, went off in 2011, but it's also quiet now).
Per the IGN Canaries director at today's PEVOLCA press conference, via browser translator and me, a little -- their emphasis:
That they emphasize how the shape of the main cone varies suggests that others besides me may have gotten excited by what the cam showed yesterday.
One of the world's top experts on Canary Island volcanism gave an interview today, too (which also might not be coincidental, after yesterday's events). It's reassuring; this guy is the Carl Sagan of Spanish volcanology and I've read some of his research papers:
It's what the volcano spotters were talking about in that tweet up above.
Beside what IGN wrote in response, such things are expected near and in an eruptive zone. A new vent might even open up there. The important thing is that the rest of the island is quiet (other Canary Islands, BTW, like Tenerife, have their own volcanoes, separate from La Palma, and are all at baseline; the submarine volcano off the coast of El Hierro, an island that's a little west of La Palma, went off in 2011, but it's also quiet now).
Per the IGN Canaries director at today's PEVOLCA press conference, via browser translator and me, a little -- their emphasis:
That they emphasize how the shape of the main cone varies suggests that others besides me may have gotten excited by what the cam showed yesterday.
One of the world's top experts on Canary Island volcanism gave an interview today, too (which also might not be coincidental, after yesterday's events). It's reassuring; this guy is the Carl Sagan of Spanish volcanology and I've read some of his research papers:
- Thread starter
- #83
Nerd stuff: The volcano "spotters" asked the Twitterverse a couple days ago about some weird rocks they found in the eruption deposits and scientists answered them today (that's not Dr. Carracedo, BTW, but he is a volcanologist, whose name escapes me right now). It's a terrific example of outreach communication!
- Thread starter
- #84
Re: that deformation, per the Canaries government site this afternoon (via browser translator):
Another deep-focus M4.5 quake happened today. Hopefully, it's as IGN tweeted above: the edifice/island is adjusting to the eruption. Again, there's almost NO surface seismicity -- exactly what we want to see on a slide-prone terrain.
Another deep-focus M4.5 quake happened today. Hopefully, it's as IGN tweeted above: the edifice/island is adjusting to the eruption. Again, there's almost NO surface seismicity -- exactly what we want to see on a slide-prone terrain.
MNTornadoGuy
Member
- Thread starter
- #86
Per this story, INVOLCAN is sending drones to see if there is also lava effusion.
Don't know if or how they might be related, but the time lag between strong deep-focus quake and change in eruption behavior is much shorter this time.
Don't know if or how they might be related, but the time lag between strong deep-focus quake and change in eruption behavior is much shorter this time.
- Thread starter
- #87
Whoa. This is a change. Tweeter is lead author of that "mafic volcanoes" paper I linked to yesterday. Image taken from observatory on island's high point.
From the ground:
From the "spotters". Wonder if that's pyroclastic flow in between the active (left) and new (right) vents. Good luck with the drones, INVOLCAN !:
From the ground:
From the "spotters". Wonder if that's pyroclastic flow in between the active (left) and new (right) vents. Good luck with the drones, INVOLCAN !:
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- Thread starter
- #88
These very recent "spotter" pictures are reassuring: a plinian column rises above winds rather than interacting with them. That hill isn't in or near the stratosphere.
Still serious, but in this layperson's opinion, also still within the range of predicted behavior, if it isn't Plinian.
Still serious, but in this layperson's opinion, also still within the range of predicted behavior, if it isn't Plinian.
MNTornadoGuy
Member
There is a strong inversion in place which is probably why the plume is spreading out like that.
- Thread starter
- #90
Drones and volcanologists rule!
- Thread starter
- #91
Here's a little more information.
Also, that inversion over La Palma -- does it have anything to do with the Saharan Air Layer?
Also, that inversion over La Palma -- does it have anything to do with the Saharan Air Layer?
- Thread starter
- #92
This is a good visualization of the overall situation on La Palma from IGN, tweeted seven hours sgo (so, nothing including the new vent ). It shows:
- The island's deformation over the summer
- Pre-eruptive seismicity and how that migrated
- The fissure line of fountains that first opened up on the 19th
- The new cone a little farther north of those, and then the devastating flows, along with the quakes that have happened during the last 36 hours.
- Thread starter
- #93
Incredible time lapse from the observatory. Gravity waves, too (read somewhere that they happen here frequently because of the Saharan Air Layer interactions, but ? details). Also informal word from a reliable source here that much of that Scary Looking Cloud may be coming from the active vent, not the new one.
PS: Still mining some amazing tweets tonight and see that I didn't imagine things yesterday, just misinterpreted the vent widening (apparently -- just going by visuals) shown here. And that's why the active cone is still going off big time. In my very limited experience of watching eruptions online, I've never seen an effusive one transition into such explosiveness, but reading does confirm that this is typical at many volcanoes.
PS: Still mining some amazing tweets tonight and see that I didn't imagine things yesterday, just misinterpreted the vent widening (apparently -- just going by visuals) shown here. And that's why the active cone is still going off big time. In my very limited experience of watching eruptions online, I've never seen an effusive one transition into such explosiveness, but reading does confirm that this is typical at many volcanoes.
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- Thread starter
- #94
Per El Mundo's coverage of today's PEVOLCA press conference, yesterday's "new" vent was actually reactivation of one of the old vents along the initial fissure lines. It's expected to vent nothing but tephra: this layperson thinks that means gas flow as at the start (gas content is what drives lava fountains), but they've probably not detected any magma underneath that part of the erupting fissure system.
The rest of the report is about lava flows, but this caught my eye (per browser translator, their emphasis):
The last M4-something shows on the IGN Twitter feed about two hours ago, an M4.3, at the deep focus.
IGN did tweet (it's linked earlier in the thread) that they felt at that point that the island was adjusting to the eruption. That's going to rock the casbah a bit in something this big, and it would even conceivably cause fissure movement like that I saw in the cam and described here (and which opened up the old vent yesterday, I think, per Itahiza's "fissure" comment above).
Why? Because this whole thing started at the southern tip of the island and moved north -- and now there is that big caldera structure standing in the way, plus the rest of the northern volcanic edifice, neither of which seem particularly movable.
Image source.
I don't understand, though, why the eruption became more ashy and explosive as that deeper focus showed up -- a trend that's increasing (ash has shut down flights to La Palma again, don't know about the other islands); why the quakes only have two foci, if the whole island is adjusting; what's happening with the fissure system. Well, there's a lot I don't understand, which is nothing new.
Am guessing, though, that the old caldera and the northern edifice are really in tectonic control of this business. The big unknown may be how much eruptible magma is down there to continue providing an irresistible force against that "immovable object."
The really good news is that reportedly there continues to be almost no seismicity at the surface. That "worst-case" scenario was debunked, but "minimal risk" does not equal "no risk." Landslides start at the top, thougn, and there appears to be no sign of trouble there, per reports.
The rest of the report is about lava flows, but this caught my eye (per browser translator, their emphasis):
The last M4-something shows on the IGN Twitter feed about two hours ago, an M4.3, at the deep focus.
IGN did tweet (it's linked earlier in the thread) that they felt at that point that the island was adjusting to the eruption. That's going to rock the casbah a bit in something this big, and it would even conceivably cause fissure movement like that I saw in the cam and described here (and which opened up the old vent yesterday, I think, per Itahiza's "fissure" comment above).
Why? Because this whole thing started at the southern tip of the island and moved north -- and now there is that big caldera structure standing in the way, plus the rest of the northern volcanic edifice, neither of which seem particularly movable.
Image source.
I don't understand, though, why the eruption became more ashy and explosive as that deeper focus showed up -- a trend that's increasing (ash has shut down flights to La Palma again, don't know about the other islands); why the quakes only have two foci, if the whole island is adjusting; what's happening with the fissure system. Well, there's a lot I don't understand, which is nothing new.
Am guessing, though, that the old caldera and the northern edifice are really in tectonic control of this business. The big unknown may be how much eruptible magma is down there to continue providing an irresistible force against that "immovable object."
The really good news is that reportedly there continues to be almost no seismicity at the surface. That "worst-case" scenario was debunked, but "minimal risk" does not equal "no risk." Landslides start at the top, thougn, and there appears to be no sign of trouble there, per reports.
- Thread starter
- #95
This tweet, even though showing propellors, reminded me of a favorite BBC video, which also is timely in that a couple of the more explosive Icelandic volcanoes are restless in their sleep and could provoke a 2010-style North Atlantic air traffic shutdown, if either, or another one up there, goes off.
Such economically costly and also annoying shutdowns are very necessary.
The tweet today from La Palma:
The video:
Such economically costly and also annoying shutdowns are very necessary.
The tweet today from La Palma:
The video:
MNTornadoGuy
Member
The upper vent is really explosive right now.
- Thread starter
- #97
There's a little good news, though: Per El Mundo via browser translator, SO2 levels are decreasing (me: that can be a sign of no new magma arriving and degassing), though the IGN Canaries director says it's not yet low enough to be a sure sign that the eruption is winding down.
Also they report that eruption levels dropped last night briefly; these soon picked up again, but the Iceland volcano, while different in important ways, also started doing this, with the quiet intervals becoming longer and longer. It's on hiatus now, at least. Hopefully, Cumbre Vieja's current eruption will do the same, and quickly, too.
Volcanologists don't know exactly why or how eruptions stop. They can only use these indirect methods, like geochemistry and seismicity, and if known, the volcano's past history (although that's not necessarily a guide to its future behavior).
Meanwhile, in what was once a neighborhood of Tacande town:
The volcano spotters also tweeted a graphic of what seems to be going on underground:
Also they report that eruption levels dropped last night briefly; these soon picked up again, but the Iceland volcano, while different in important ways, also started doing this, with the quiet intervals becoming longer and longer. It's on hiatus now, at least. Hopefully, Cumbre Vieja's current eruption will do the same, and quickly, too.
Volcanologists don't know exactly why or how eruptions stop. They can only use these indirect methods, like geochemistry and seismicity, and if known, the volcano's past history (although that's not necessarily a guide to its future behavior).
Meanwhile, in what was once a neighborhood of Tacande town:
The volcano spotters also tweeted a graphic of what seems to be going on underground:
- Thread starter
- #98
Also, i just read (Spanish) that there is deflation of the edifice in places away from the eruption zone. IMO, although they say it is slight, that's very good news, even though the eruption looks very scary tonight.
It's awful for Los Palmeros, but as Dr. Carracedo told EFE, things would be a lot worse if that magma was trapped underground.
It's awful for Los Palmeros, but as Dr. Carracedo told EFE, things would be a lot worse if that magma was trapped underground.
- Thread starter
- #99
This is cool, too: seismicity and horizontal deformation (arrows) from the eruption's start through yesterday (? cutoff time):
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- #100
They had an M4.9 a few hours ago at the deep focus (24 miles/39 km) -- the strongest one in the eruption-related series. Per El Mundo, it was even felt over on Tenerife.