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Researchers Find Some Volcanoes 'Scream' At Increasing Pitches Until They Blow 59

Posted by samzenpus
from the call-of-the-volcano dept.
vinces99 writes "Swarms of small earthquakes often precede a volcanic eruption. They can reach such rapid succession that they create a "harmonic tremor" that resembles sound made by some musical instruments. A new analysis of an eruption sequence at Alaska's Redoubt Volcano in March 2009 shows the harmonic tremor glided to substantially higher frequencies and then stopped abruptly just before six of the eruptions. Scientists at the U.S. Geological Survey's Alaska Volcano Observatory have dubbed the highest-frequency harmonic tremor at Redoubt Volcano 'the screams' because the episodes reach such high pitch compared with a 1-to-5 hertz starting point. Alicia Hotovec-Ellis, a University of Washington doctoral student in Earth and space sciences and an author of two papers examining the phenomenon, has created a 10-second recording and a one-minute recording that provides a 60-times faster representation of harmonic tremor and small earthquakes."
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Researchers Find Some Volcanoes 'Scream' At Increasing Pitches Until They Blow

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  • Thetans ... (Score:1, Informative)

    by Anonymous Coward

    It's the thetans getting ready to take a massive shit in Tom Cruise's mouth and fill him with even more blessings.

    • "It's the thetans getting ready to take a massive shit in Tom Cruise's mouth and fill him with even more blessings."

      Um, no. I don't think that's the way it works. I... scream. Ice cream. Yeah, that's the ticket.

      Look, let's be honest. I tend to scream a bit before I explode, too. So do you. Female or male, bad explosion or good explosion, you either scream a bit or you're hopelessly Victorian.

      "I say... you have trodden on my foot with your pegleg. Do you mind, terribly?"

      (censored)

  • by djh101010 (656795) on Monday July 15, 2013 @01:23PM (#44286485) Homepage Journal
    So, it's like a teapot when it gets boiling?
  • At their peak, just before they blow, these "screams" get to a high enough frequency that humans could hear them. Of course, to us it would sound like a low frequency rumble.

    In other words, if you are standing on a volcano, and start to hear it grumble, get away. Fast.

    • by Anonymous Coward

      At their peak, just before they blow, these "screams" get to a high enough frequency that humans could hear them.

      Actually, the screams are the noises of people. This is because the volcanoes sound like accordions.

    • by ackthpt (218170) on Monday July 15, 2013 @02:11PM (#44287091) Homepage Journal

      At their peak, just before they blow, these "screams" get to a high enough frequency that humans could hear them. Of course, to us it would sound like a low frequency rumble.

      In other words, if you are standing on a volcano, and start to hear it grumble, get away. Fast.

      About 12 years ago there were swarms of tremors around the Long Valley, near Mammoth Mountain, California. 600-800 earthquakes per day from sub 1.0 to 3.0+ and elevation changes around the caldera indicated pressure was building. Then suddenly nothing happened and they subsides. Still a few here and there, but some activity took place and then ended. Massive false alarm or very long range warning? You scare a lot of people with eruption talk, which doesn't materialize, and you'll have most of them home when it suddenly goes BOOM without warning.

      • by Anonymous Coward

        The rumblings and quakes were warning of a geological pressure release. That the release did not include hundreds of tons of ash in the sky and rivers of molten stone is a good thing.

        It is important to remember that 'signs of a potential eruption' are not a 'promise of imminent eruption' but are the best forecast typically available. This is similar to medical evaluations, many harmless conditions have symptom lists that only differ from life-threatening by one factor that requires difficult testing. Ign

      • and you'll have most of them home when it suddenly goes BOOM without warning.

        Hos is that different than not warning at all?

        • by ackthpt (218170)

          and you'll have most of them home when it suddenly goes BOOM without warning.

          Hos is that different than not warning at all?

          Effectively what we know as the 'cry wolf' example. California is no stranger to people who like their name in the news for predicting the next big quake, but when it doesn't happen they're shamed for a bit and then drop into anonimity. People stop listening to doom projectors - next thing you know, someone knew what they were talking about because they heard the seismic precursors and they get ignored as yet-another crackpot.

    • So what I'd like to know is: do Elephants (who's auditory range of 16-12,000 hertz covers much more of the tremors) always know when a nearby volcano is going to erupt?

  • Even so (Score:4, Funny)

    by Sparticus789 (2625955) on Monday July 15, 2013 @01:43PM (#44286749) Journal

    I bet the volcano's still have better pitch control than Justin Beiber.

    • by Jmc23 (2353706)
      What's sad about your attempt at humour is probably nobody here listens to Justin Bieber. Now, if it's true, you've outed yourself as someone who has not only recognized Biebers singing but listened to it enough to make that determination. If it's false, then you've outed yourself as an idiot who puts down successful people (no matter how immature), probably just to make yourself feel better about your unsuccessful life.
      • Would you prefer something more like "The Song of Ice and Fire: A Volcano's song"?

      • by cusco (717999)
        He probably has a pre-teen daughter and has had enough Bieber inflicted on him to make that particular whine immediately recognizable. I feel for my niece, who is in the same situation.
  • by hackingbear (988354) on Monday July 15, 2013 @01:54PM (#44286875)

    some volcanoes will erect before they blow.

  • by sl4shd0rk (755837) on Monday July 15, 2013 @01:55PM (#44286891)

    after a night at Taco Bell

    • by operagost (62405)
      Both also result in a huge release of methane and boiling hot, liquefied matter. The similarities are amazing!
  • How many db? (Score:5, Interesting)

    by Anonymous Coward on Monday July 15, 2013 @02:05PM (#44287017)
    Could this be a possible explanation to how animals sometimes perceive an impending disaster? What decibel would this be at from, say, five miles?
  • Check out the time compressed sound recordings- pretty awesome.

  • by Anonymous Coward

    This obviously does not apply to volcanoes in space.

    Because in space, no one can hear you scream.

  • ... if they're faking it?

  • Volcano [wikipedia.org] IS a woman!

  • Volcanoes always fascinated me, especially in my school days. I remember reading in history about how a whole city was carpeted by volcanic ashes and suffocated everything. Now to read about the ‘screaming’ volcanoes it seems more of a mythic happening. I’m certain people of old had some interesting stories to attach to this attribute of volcanoes. Sandra V. Bolee.com

Faith may be defined briefly as an illogical belief in the occurence of the improbable. - H. L. Mencken

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