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Wednesday, September 7, 2016

Quiescence: Not Just for Popsicles Any More; A Nicaraguan Volcano Goes Quiet Just Before Eruption

      Volcano semiotics indicating when a volcano is going to erupt include seismographs that display an increase in small tremors which might indicate that magma beneath the mountain is moving, a release of volcanic gases like sulfur dioxide and carbon dioxide, and changes in the physical shape of the volcano such as depressions or growths.




      While these clues tell researchers that the forces that fuel eruptions are moving, they don’t necessarily provide a timeline for when the eruptions will occur.





      By looking at the rate at which earthquakes happen in Nicaragua’s Telica Volcano, a team of scientists studying the volcano have discovered a new method of forecasting volcanic explosions. Their study, published this month in Earth and Planetary Science Letters, describes a period of seismic quiescence, or quiet time, that occurs immediately before an individual explosion.



      Volcanic eruptions are generally made up of many different explosions which can span hours, days, or even months. Depending on how much pressure has been building within the volcano, these individual explosions can range from small bursts of steam to giant, gaseous plumes of ash and smoke. Many smaller eruptions, those on the lower end of the Volcanic Explosivity Index (VEI), occur with little consequence to the people living in the region, while the larger explosions can have devastating effects on nearby communities.




      “We first realized the potential impact of our finding as the 2011 eruption of Telica was in progress and we started to understand that there was a pattern of precursory seismic quiescence prior to each explosion”, says Dr. Diana Roman, one of the study’s co-authors. “We were very excited about the forecasting potential of the quiescence at that time, but we had to do quite a lot more work after the eruption was over to understand the phenomenon and its relationship to the volcano's activity.” [One of the only other time I see the word quiescent is on "quiescently frozen popsicles."]






      Of the 50 explosions studied during Telica’s 2011 eruption, 48 of them were preceded by some sort of seismic silence.




      In addition, there appeared to be a correlation between the length of the quiet time and how catastrophic each explosion was. In short—the longer the quiet time, the more volatile each explosion was. Why does this happen?



     The team discovered that the pathways along which the volcanic gases escape become sealed, which builds pressure. The longer these gases spend trapped beneath the surface, the larger and more catastrophic the ensuing eruption is. The researchers suspect that newly formed minerals might block pathways inside the volcano, or possibly the pathways simply collapse, impeding avenues of escape for volcanic gases.




      Although each eruption is different, and so is each volcano, the implications of a study like this could be far-reaching.

      “I think there is great potential for our findings to be used in a real-time monitoring context,” Dr. Roman says, “the quiescence signal is relatively easy to detect as it requires only one seismometer rather than a large network of seismometers, meaning it can be implemented more cheaply.”



The closer scientists get to predicting volcanic eruptions, the more easily people can learn to live along the flanks of volcanoes such as Telica.



      

Quiescently unfrozen in the Rocky Mountains,
Steph

49 comments:

  1. Replies
    1. Yes, jan, all over the interwebs. Now with plenty of space, no explosions, small or large.

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  2. I accept without protest acquiescently frozen desserts.

    (As opposed to frozen deserts, like on Mars or Antarctica.)

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    Replies
    1. I knew dis topic was ripe for dis-course. 😀

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  3. It seems like earthquake behavior may be the worst possible for human behavior. For us, the longer nothing's happened, the safer we feel. Convincing people to get more worried the longer the volcano's been quiescent may take some doing.

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    Replies
    1. Indeed, jan. Quiescently molten leads to feelings of safety for humans. I wonder how soon danger is sensed for animals. I know animals sense when things are moving in volcanic explosions, earthquakes, and tsunamis.

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  4. Popsicle!
    Not so quiescent.
    Kinda adolescent.

    Legolescent

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  5. Popsicle!
    Not so quiescent.
    Kinda adolescent.

    Legolescent

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  6. Replies
    1. zeke creek, yes, the clam, er, dam, before the storm (with some bad kerning).

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    2. When life gives you chlamydia, make chlam chowder.

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  7. Shows the importance of letting off a little steam now and then. When the Yellowstone caldera blows again we'll have a couple of very red states.

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    Replies
    1. eco, indeed. What's your new thumbnail image? A red state?

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    2. Mount Wheeler in Great Basin NP, Utah. Though I don't think it has volcanic origins - Shasta and Lassen (legit volcanoes) photos are old, not digital....

      So today's image is a small strawbale house built on a very hard basaltic rock flow from Mount Konocti, which last blew its top around 11,000 years ago. In addition to very hard ground it did leave behind a very large and pretty lake.

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    3. Hmm, eco, I know Wheeler Peak in Great Basin NP in Nevada (land of 100's of caterpillars marching northward from Mexico). . .but not Utah.

      The strawbale house looks quite cool. Great environs, too, in this "High Threat Potential" area of CA. What is the roof like?

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    4. You're right, Nevada, not Utah. It was on the return leg of a trip to Utah to buy a biodiesel car, back when they were hard to get in California.

      The house is a dodecagon connected to a decagon by a small hallway. The roofs are conic shapes (volcano reference??), the larger with a cupola for light and ventilation, the smaller with a simple light tube.

      Funny you mention the "High Threat Potential"; most people up there don't spend much time worrying about another eruption, but a very large wildfire last year came within 400 yards or so of the house.

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    5. Maybe it's the volcanic shapes that are so appealing.

      Yes, I can see where fire danger would be much more immediate. 400 yards is darn close!

      Do you like the biodiesel car?

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    6. The car (2003 Jetta) has been good for the most part, had it 11 years. Unfortunately the State has been beating up on the local fueling station, so it's harder to get locally-sourced recycled vegetable oil. My small part to slow down the drive to perdition....

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    7. I have a friend who drove across the country for a year in a biodiesel bus, stopping at fast food places along the way for fuel. When he went to go for interviews for "real jobs" after that, interviewers were all over the bus experience and asked about nothing else on his resume.

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    8. That's a true straight vegetable oil (SVO) vehicle, which requires a second fuel tank and much more discipline (switching between tanks) than I am prepared to tolerate.

      I just run biodiesel, which is a no-brainer for most diesel vehicles. Rudolf Diesel designed the engine to run on vegetable oil; 100 years ago farmers didn't have an Esso station nearby. But with modern fuel injection the vegetable oil can gum up at low temperatures - even modest night time temps well above freezing.

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    9. I didn't know there was a difference between SVO and biodiesel. Nor that modest night time temps could be a problem.

      John said initially he liked the French fry smell but got over that half way into the trek. He and his partner have now fit the bus with full solar, a back up boat stove, and have parked their bus-home on private land with all the other hippie farmers in north-central Massachusetts. Beautiful country surrounded by National Forest. . .and no more French fry smell.

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    10. Biodiesel has a slight french fry smell, not as strong as SVO, but a lot nicer than those horrid diesel buses we rode as kids or in college.

      Veggie oil is processed into biodiesel, not that complicated, can do it at home, but it's messy and you end up with a lot of glycerine to deal with. I suppose if you want to make your own soap. Maybe it's the glycerine that gums up the works, I can't remember.

      If you run SVO you typically start the car with dino diesel or biodiesel (tank 1), there's a heat exchanger in tank 2 to warm up the veggie oil, and after about 5 minutes you switch to run on that. But then you have to remember to switch back to tank 1 a few minutes before you stop, so there's no leftover veggie oil in the lines or injectors. Too much thinking.

      Life is tougher in Colorado, even biodiesel will congeal in cold temperatures, <30 or so, and they recommend running a blend of dino and biodiesel if that's the case. I think no biodiesel below 5 or so. We rarely get sub-freezing here.

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    11. Tanks for the biodiesel and SVO lesson, eco. All that switching back and forth does sound like a pain. Most oil and gas is not from dinos, though, but from much smaller, often water-bourne, dead critters.

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    12. And mostly from bacteria. . .But bacteria don't look as cool as the Sinclair mascot!

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    13. And just how do you know dino isn't my shorthand for Dinoroseobacter shibae?

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    14. Dinoroseobacter shibae?
      I can't even pronounce that.

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    15. I swear on a stack of Donald Trump hairpieces.

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    16. OK, that was worth it just to see your thumbnail image, eco.

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    17. FYI it's the caterpillar stage of the Peruvian flannel moth. Part of megalopyge (big (t)rump) family, it also has a toxic sting if you touch it or watch it on TV.

      Isn't nature amazing?

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    18. I call that flannel moth "Dino."

      And, yes!

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    19. While I was biking through the swamp this morning, a particularly fragrant garbage truck passed and got me thinking: with exhaust that smells like French fries and all that food in the tank, do you have to hang your biodiesel car from a tree when you go camping, so the bears don't ransack it?

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  8. Replies
    1. Maizie, now listen to me, Maizie; it's for Science! Yeah, that's right, Science. Yeah! OK? Yeah; attagirl, Maizie; good girl, Maizie!

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    2. We faced a similar challenge when our 3-month old son, who never lay still when something was going on, needed to lie still for a CT scan. We were sure he'd need general anesthesia. Son of a gun chose that moment to fall asleep, just like that.

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    3. Paul, Maizie heard you! Speaking dog is quite the Art (and Science 😃).

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    4. Cute video version of the history of dogs. Now Maizie, some of the mean dogs in school may tease you because you are from mixed heritage....

      Always reminds me of this cartoon.

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    5. And I'm embarrassed to say it reminds me of this 1970's song.

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    6. Fascinating, stuff, eco. (Maizie, alas, was unimpressed.)

      And how can any of us forget Cher singing the HB song?!

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    7. Having had both a cat (Chally, short for Chalybeate, originally from the Greek meaning iron-bearing) and, now, a dog, these are both so spot on. Thanks, eco.

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  9. Found a good dim sum restaurant in Fort Lee, for lunch on our way to NY. They make a great sautéed pea shoot leaves dish that my wife, with a nod to Lynn Truss, calls "Peas, shoots, and leaves." Their customer loyalty cards feature a cat-shaped punch, and promise "5 cats = free soup dumpling," which I find amusing, given the old slander about Chinese restaurants and cats.

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    Replies
    1. Gotta love commas and cats and the "Eats Shoots and Leaves") take-off.

      The sautéed pea shoot leaves dish sounds wonderful!

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    2. I had to look that one up. I was afraid it pertained to where Justice Kagan ate Christmas dinner.

      Moving on to Indian Fossils, which I presume are not Native American Fossils, but I don't really know, yet.

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    3. There's a clip for everything, eh? And we are not talking hair here. . .

      Looking forward to your thoughts on the Indian fossils from coal beds.

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  10. New post on "Speaking of Geologic Time Periods Ending in E: Indian Fossils and the Spread of Primate-Like Animals: India's Island Days" is now up.

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