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

samzenpus posted about a year ago | from the call-of-the-volcano dept.

Science 59

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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Thetans ... (1, Informative)

Anonymous Coward | about a year ago | (#44286457)

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

harmonic tremor, screaming? (-1, Redundant)

noh8rz8 (2716593) | about a year ago | (#44286903)

the question is, does the frequency reach 20 - 20,000 htz? if not, we're not gonna hear it...

Re:harmonic tremor, screaming? (5, Informative)

rullywowr (1831632) | about a year ago | (#44288095)

If you RTFA you would see this:

She documented the rising tremor frequency, starting at about 1 hertz (or cycle per second) and gliding upward to about 30 hertz. In humans, the audible frequency range starts at about 20 hertz, but a person lying on the ground directly above the magma conduit might be able to hear the harmonic tremor when it reaches its highest point (it is not an activity she would advise, since the tremor is closely followed by an explosion).

However this is slashdot so no need to RTFA, just carry on with redundant questions veiled in the shape of a seemingly innocuous post.

Re:harmonic tremor, screaming? (1)

noh8rz8 (2716593) | about a year ago | (#44290741)

my policy is to not follow links. if some information was important enough, it would be put in the summary / post. if it's not important, then you just refer people to the link. so i just stick to what's important and not waste time on the links.

Re:harmonic tremor, screaming? (1)

antifoidulus (807088) | about a year ago | (#44291279)

But how else am I supposed to use the force to lava-surf?

Re:Thetans ... (1)

Jane Q. Public (1010737) | about a year ago | (#44292801)

"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)

Makes sense, fluid dynamics and all that... (5, Interesting)

djh101010 (656795) | about a year ago | (#44286485)

So, it's like a teapot when it gets boiling?

Re:Makes sense, fluid dynamics and all that... (-1)

Anonymous Coward | about a year ago | (#44286839)

Or like my girlfriend, when I'm doing my boyfriendly duties correctly!

Re:Makes sense, fluid dynamics and all that... (4, Funny)

Captain Hook (923766) | about a year ago | (#44286927)

catching the spiders she's just spotted?

Re:Makes sense, fluid dynamics and all that... (2)

NatasRevol (731260) | about a year ago | (#44287169)

Folding laundry?

Re:Makes sense, fluid dynamics and all that... (2, Funny)

Anonymous Coward | about a year ago | (#44286921)

More like normal farts at normal frequencies and intervals. Then, suddenly you are attacked by frequent small, higher pitched flatus, while you fast walk with clenched buttocks to the closest toilet. As the intervals become shorter and the frequencies become higher still, you know it is moments before the disaster.

You all know what I'm talking about.

I'm not a lactose bigot or anything, I try to be tolerant but even so I can only take so much dairy.

Re: Makes sense, fluid dynamics and all that... (1)

Anonymous Coward | about a year ago | (#44287261)

It's because the "tube" (colon) gets shorter in length as the fecal matter descends further. So the fart is higher pitched. Like a trombone!

Re: Makes sense, fluid dynamics and all that... (0)

Anonymous Coward | about a year ago | (#44289869)

It has more to do with butthole tension... which just happens to be the name of my band

Re:Makes sense, fluid dynamics and all that... (2)

rullywowr (1831632) | about a year ago | (#44288109)

So you went to Taco Bell last night?

Re:Makes sense, fluid dynamics and all that... (2)

ackthpt (218170) | about a year ago | (#44287035)

So, it's like a teapot when it gets boiling?

Would that you could get thousands of atmospheres of pressure in your teapot.

I tend to think of it as the Earth doing its own version of Fracking. Without so much as a permit or 'By your leave, good people of the lands.'

Krakatoa must have had some pitch before it popped, which it will do again some day, such is its activity cycle.

Re:Makes sense, fluid dynamics and all that... (1)

sociocapitalist (2471722) | about a year ago | (#44287163)

So, it's like a teapot when it gets boiling?

Or maybe a....pressure cooker?

We should be scientists and get grant money and grad students and and um...

Re: Makes sense, fluid dynamics and all that... (1)

jd2112 (1535857) | about a year ago | (#44288091)

Fluid dynamics has little to do with it. I often scream before I now my top as well.

There's a sexual joke in there somewhere... (0)

Anonymous Coward | about a year ago | (#44286521)

There's gotta be!

Just... (0)

Anonymous Coward | about a year ago | (#44286575)

...like my wife.

So do I until my GF fixes me right up (0)

Anonymous Coward | about a year ago | (#44286583)

Gigidity

(the password is: squirt)

Up into the human range (1)

mbone (558574) | about a year ago | (#44286627)

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.

Re:Up into the human range (0)

Anonymous Coward | about a year ago | (#44286693)

If you read "grumble grumble" instead of hearing it, you're just playing Zelda 1... so don't panic

Re:Up into the human range (1)

Anonymous Coward | about a year ago | (#44286725)

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.

Re:Up into the human range (3, Interesting)

ackthpt (218170) | about a year ago | (#44287091)

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.

Re:Up into the human range (1)

Anonymous Coward | about a year ago | (#44287185)

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. Ignore the rest at your own (eventual) peril.

Re:Up into the human range (1)

NatasRevol (731260) | about a year ago | (#44287233)

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

Hos is that different than not warning at all?

Re:Up into the human range (1)

ackthpt (218170) | about a year ago | (#44290103)

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.

Re:Up into the human range (0)

Anonymous Coward | about a year ago | (#44287103)

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

FTA: "the tremor is closely followed by an explosion"

Unless you have a teleporter, by the time you hear it, you'd probably be killed by the acceleration required to get away fast enough to reach a safe distance.

Re:Up into the human range (0)

Anonymous Coward | about a year ago | (#44287131)

[...]if you are standing on a volcano, and start to hear it grumble, get away. Fast.

If you are standing on a volcano, and start to hear it grumble, you will soon be going away, very fast.

Re:Up into the human range (2)

Em Adespoton (792954) | about a year ago | (#44289993)

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?

Take my wife please (0)

Anonymous Coward | about a year ago | (#44286639)

Sounds like many a marriage, except after the wedding all blowing stops.

Re:Take my wife please (1)

Anonymous Coward | about a year ago | (#44287645)

as far as you know....

Even so (3, Funny)

Sparticus789 (2625955) | about a year ago | (#44286749)

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

Re:Even so (2)

Jmc23 (2353706) | about a year ago | (#44287049)

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.

Re:Even so (1)

Sparticus789 (2625955) | about a year ago | (#44287083)

Would you prefer something more like "The Song of Ice and Fire: A Volcano's song"?

Re:Even so (1)

cusco (717999) | about a year ago | (#44288681)

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.

Re:Even so (1)

Jmc23 (2353706) | about a year ago | (#44289391)

Sometimes I wonder how parents haven't heard of earbuds/headphones.

Re:Even so (0)

Anonymous Coward | about a year ago | (#44289497)

Sometimes I wonder how parents haven't heard of earbuds/headphones.

Some parents refuse to allow their children to use headphones, lest they should covertly listen to songs about offing pigs and such... IMO, those parents deserve the aural torment they've chosen for themselves.

Under the island, middle of the mountain (0)

Anonymous Coward | about a year ago | (#44287637)

There's a big bad boomin' system, blowing speakers, woofers and tweeters.

and also (3)

hackingbear (988354) | about a year ago | (#44286875)

some volcanoes will erect before they blow.

sounds like my bathroom (2)

sl4shd0rk (755837) | about a year ago | (#44286891)

after a night at Taco Bell

Re:sounds like my bathroom (2)

operagost (62405) | about a year ago | (#44287235)

Both also result in a huge release of methane and boiling hot, liquefied matter. The similarities are amazing!

How many db? (5, Interesting)

Anonymous Coward | about a year ago | (#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?

Re:How many db? (0)

Anonymous Coward | about a year ago | (#44287855)

That was my exact take on this.

Re:How many db? (-1)

Anonymous Coward | about a year ago | (#44288529)

No, animals perceive natural disasters because of `nature` and some other `wife's tale pie-in-the-sky gobbledygook`. Please refrain from science, it's damaging people's views of the world!

For those who didn't RTFA (1)

avandesande (143899) | about a year ago | (#44287249)

Check out the time compressed sound recordings- pretty awesome.

Volcanoes in Space (1)

Anonymous Coward | about a year ago | (#44287289)

This obviously does not apply to volcanoes in space.

Because in space, no one can hear you scream.

My girlfriend does the same thing. (1)

gestalt_n_pepper (991155) | about a year ago | (#44287383)

More than coincidence?

Re:My girlfriend does the same thing. (1)

Rakarra (112805) | about a year ago | (#44288161)

It all makes sense.
Volcanoes are drama queens and attention whores.

Re:My girlfriend does the same thing. (0)

Anonymous Coward | about a year ago | (#44293863)

You'll need to put some videos online for us to analyse. We'll let you know in due course, once the videos are posted.

How can you tell ... (1)

PPH (736903) | about a year ago | (#44287543)

... if they're faking it?

Re:How can you tell ... (2)

Lithdren (605362) | about a year ago | (#44288495)

... if they're fracking it?

wrong (0)

brainspank (515274) | about a year ago | (#44288075)

it's the giant lemongrabs

So, Hawaiians are right! (1)

GodfatherofSoul (174979) | about a year ago | (#44288773)

Volcano [wikipedia.org] IS a woman!

Re:So, Hawaiians are right! (0)

Anonymous Coward | about a year ago | (#44290717)

How do you know it's a woman's scream and not Ned Flander's? https://www.youtube.com/watch?v=Tb8t25ePTlg

Interesting (1)

Sandra V. (2984885) | about a year ago | (#44311411)

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
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