Go Back  PPRuNe Forums > PPRuNe Social > Jet Blast
Reload this Page >

La Cumbre Viejo

Jet Blast Topics that don't fit the other forums. Rules of Engagement apply.

La Cumbre Viejo

Old 19th Oct 2021, 05:23
  #121 (permalink)  
 
Join Date: Aug 2008
Location: Canada
Posts: 101
Originally Posted by India Four Two View Post
Spectacular photo of lava falls and the new delta.
Thanks for that, easily located with Google Earth.
Zombywoof is offline  
Old 20th Oct 2021, 22:51
  #122 (permalink)  

Flashes from the Archives of Oblivion
Thread Starter
 
Join Date: Jan 2000
Location: 03 ACE
Age: 70
Posts: 929
Stronger by the week !
El Grifo
El Grifo is offline  
Old 21st Oct 2021, 01:52
  #123 (permalink)  
 
Join Date: Dec 2017
Location: Yakima
Posts: 150
Is there a chance of an explosive eruption a la Mt. St. Helens or will this continue as lava flow?
Winemaker is offline  
Old 21st Oct 2021, 02:26
  #124 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
I was a passenger in a window seat on a commercial flight that flew over Mt Saint Helens enroute to elsewhere a few months after the explosion.

I cannot imagine what amount of power it took to create that huge of a gaping hole in a mountain of that size…

Nor what led a few poor souls to ignore all the warning signs and stay in place, never to be heard from again.

Look up ”pyroclastic flow” on Wikipedia, which “is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of 100 km/h (62 mph) but is capable of reaching speeds up to 700 km/h (430 mph).”

So far, this volcano is far from that. Doesn’t make it any less destructive given that it is presumably far harder to relocate and start anew.

visibility3miles is offline  
Old 21st Oct 2021, 03:36
  #125 (permalink)  
 
Join Date: Nov 2011
Location: Japan
Posts: 865
Mt Vesuvius must have rumbled and fountained and flowed for a while, lulling the local inhabitants of Pompeii and Herculaneum into thinking, “If that’s all she’s got, then we might as well get on with life.”
jolihokistix is online now  
Old 21st Oct 2021, 04:39
  #126 (permalink)  
 
Join Date: Jun 2002
Location: CEH2 (Black Diamond, Alberta)
Posts: 5,665
Is there a chance of an explosive eruption a la Mt. St. Helens or will this continue as lava flow?
Volcanos on oceanic islands, for example the Canaries, Iceland or Hawaii, are mostly created from basaltic magmas, which have a very low silica content and thus a very low viscosity, resulting in the typical fast lava flows we are seeing in the current eruption. It is unlikely that there will be an explosive event at La Cumbre Viejo.

Volcanos on continental margins like Mt. St. Helens, usually have andesitic* magmas, which contain more than 50% silica. This makes the magmas very viscous, which often results in the development of plugs or lava domes, which allow pressure to build up, which is then relieved in an explosive event.

Following on from visibility3miles' comments, a few years ago, I was driving up the west coast from Los Angeles to Vancouver BC. After stopping off to see the Spruce Goose at McMinnville, I detoured off Interstate 5 to drive up to the Johnston Ridge Observatory and Visitor Center. The viewpoint is about three miles from the crater and even though I had seen many photos, the reality of the magnitude of the crater is breathtaking.

jolihokistix mentioned Vesuvius and has hit on an unusual feature of this volcano. The magmas in this area - the Roman Comagmatic Province - are very variable, so Vesuvius has a history of both explosive and effusive (lava) eruptions. More here:
https://www.volcanotrek.com/vesuvius_volcano.htm

* Wikipedia has more than you probably want to know about how andesitic magmas develop:
https://en.wikipedia.org/wiki/Andesite

https://en.wikipedia.org/wiki/Cascade_Volcanoes




Last edited by India Four Two; 22nd Oct 2021 at 07:18.
India Four Two is online now  
Old 21st Oct 2021, 10:29
  #127 (permalink)  
 
Join Date: Apr 2007
Location: Hawaii
Posts: 132
Just to add to India's excellent post, both the Canaries and Hawaii eruptions occur over a hotspot (Iceland is a little different as it's over a rift zone). I don't know much about the history of eruptions in the Canaries, but there have been explosive eruptions in Hawaii - much like Mount St Helens but on a much smaller scale. Historically, they are rare and as far as I know, don't happen during a typical volcanic eruption we see La Cumbre Viejo or the current eruption at Kilauea. However, explosive events can't be ruled out at some point - you just need magma trapped underground heating groundwater and you may end up with explosions, but even that hypothesis is being questioned, at least for Kilauea.

https://www.usgs.gov/center-news/vol...ptions-k-lauea

In any case, evidence suggests that as long as the current eruption continues as it is, the chance of a major explosive eruption is small.
Hokulea is offline  
Old 21st Oct 2021, 11:04
  #128 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
The winds seemed to have shifted and the sun has risen.

The dull roar is actually soothing, but I live nowhere near there.

It’s a stark threat, unlike the subtle aspects of Covid or politics.

visibility3miles is offline  
Old 21st Oct 2021, 11:21
  #129 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565

Mount Saint Helens

Before and after photos. Apparently the lava dome is building itself anew, so it could blow again someday.

Before May 18, 1980, Mount St. Helens' summit altitude of 9,677 feet (2,950 meters) made it only the fifth highest peak in Washington State. It stood out handsomely, however, from surrounding hills because it rose thousands of feet above them and had a perennial cover of ice and snow. The peak rose more than 5,000 feet (1,524 meters) above its base, where the lower flanks merge with adjacent ridges.On May 18, 1980, the volcano lost an estimated 3.4 billion cubic yards (0.63 cubic mile) of its cone (about 1,300 feet or 396 meters in height), leaving behind a horseshoe-shaped crater (open to the north), with the highest part of the crater rim on the southwestern side at 8,365 feet (2,550 meters) elevation.
visibility3miles is offline  
Old 21st Oct 2021, 11:49
  #130 (permalink)  

Flashes from the Archives of Oblivion
Thread Starter
 
Join Date: Jan 2000
Location: 03 ACE
Age: 70
Posts: 929
Some good background here Hokulea :-https://en.m.wikipedia.org/wiki/Geol...Canary_Islands
El Grifo is offline  
Old 21st Oct 2021, 12:00
  #131 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
This leads to an insane thought: If you know you have something like Mount St. Helens that you know is getting ready to blow, could you set up one of those huge mine/tunneling drilling machines into its flank under robotic control and let it ease the pressure, or at least redirect the explosive force in a less lethal direction?

I know, seems like a comic book scenario, where Superman swoops in to save the day.

It’s akin to wishing you could carve a a huge funnel / ditch in the earth to give the lava an easy channel to the sea and divert it away from inhabited locations. I think they have tried/done that upon occasion.
visibility3miles is offline  
Old 21st Oct 2021, 12:43
  #132 (permalink)  

Flashes from the Archives of Oblivion
Thread Starter
 
Join Date: Jan 2000
Location: 03 ACE
Age: 70
Posts: 929
A Pint of what you have been drinking please Vis3miles 😝😝
El G.
El Grifo is offline  
Old 21st Oct 2021, 12:56
  #133 (permalink)  
 
Join Date: Jan 2008
Location: Glorious Devon
Posts: 466
Lava flows have been diverted and/or halted in the past but putting a safety valve on a volcano is probably still a tad on the science fiction side. Apart from any materials science issues, knowing where to aim it and how to steer it might be problematic
Ninthace is offline  
Old 21st Oct 2021, 13:05
  #134 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
I did say that it was an insane thought…

Perhaps I’ve seen too many movies (okay, one or two) where they set off nukes to divert killer asteroids or “re-ignite” the sun after it went cold.
visibility3miles is offline  
Old 21st Oct 2021, 14:46
  #135 (permalink)  

Flashes from the Archives of Oblivion
Thread Starter
 
Join Date: Jan 2000
Location: 03 ACE
Age: 70
Posts: 929
Not as bad as La Grifa's suggestion when the eruption started.
"Could the Fire Brigade not just put it out" Sez She !

El Grifo 😃
El Grifo is offline  
Old 21st Oct 2021, 18:19
  #136 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
There are three dogs trapped by the lava that they want to rescue by drones:
https://apple.news/AP4OGOW3TQSudyJUUKw20xA
visibility3miles is offline  
Old 21st Oct 2021, 19:08
  #137 (permalink)  
 
Join Date: Jan 2010
Location: Edinburgh
Age: 83
Posts: 52
Chat says that when the drone got there, the dogs were gone!
DType is offline  
Old 21st Oct 2021, 20:15
  #138 (permalink)  
 
Join Date: Jul 2007
Location: Still above ground
Posts: 38
Originally Posted by DType View Post
Chat says that when the drone got there, the dogs were gone!
Apparently by a group who didn't want to get in trouble for entering a prohibited area... Dogs trapped by La Palma eruption ‘saved by mysterious gang’ | Spain | The Guardian
Fargo Boyle is offline  
Old 21st Oct 2021, 23:06
  #139 (permalink)  
See and avoid
 
Join Date: Mar 2003
Location: USA
Posts: 565
The song associated with the video sounds like, “I Will Survive,” by Gloria Gaynor, sung in Spanish, not that my Spanish is good enough to translate it.

Still, an appropriate tune for dogs isolated that long.

P.S., But no, it’s this song:


Last edited by visibility3miles; 21st Oct 2021 at 23:16.
visibility3miles is offline  
Old 22nd Oct 2021, 10:05
  #140 (permalink)  
 
Join Date: Apr 2007
Location: Hawaii
Posts: 132
I've been following Bushcraft Bear's youtube channel for the last few weeks, and am very grateful to him for providing first-hand observations from La Palma. I am curious about one of his latest videos though and wondered if someone with more knowledge or info might explain?


The video includes a discussion about the risk of larger earthquakes happening, even up to magnitude 6 (I'm not sure which magnitude scale is being used, but that's a strong earthquake). This seems to be quite different from what happened during the 2018 eruption in Hawaii when there was a very large earthquake to start with (mag 6.9, I won't forget that), and then the strength of the earthquakes decreased, if not their frequency. For La Palma, it seems to be going the other way.

I understand some of this might be random chance, but if any experts could explain what might be happening and why the chances of larger earthquakes are increasing, I'd be very interested to read your opinion.
Hokulea is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.