Slow Earthquake
December 5, 2018 7:30 AM   Subscribe

These waves didn't just zip by; they rang for more than 20 minutes. And yet, it seems, no human felt them. Was it a meteor strike? A submarine volcano eruption? An ancient sea monster rising from the deep?
posted by Mr.Pointy (21 comments total) 17 users marked this as a favorite
 
this is very interesting. I had not heard of this slow quake phenom before. I hope they are able to figure out some things about it, such as relationship of these slow, global 'ringers' to local quakes, esp. biggies like Alaska just experienced.
posted by supermedusa at 8:58 AM on December 5 [1 favorite]


Oh, probably just the Earth's crust slowly creaking open like a Cadbury Creme Egg, spilling its molten guts to cleanse the world of this clusterfuck. Not to mix my metaphors, but an apocalyptic Kinder Surprise, if you will.
posted by Krazor at 9:12 AM on December 5 [19 favorites]


I just got the image in my head of the scene in "Alien" when the baby creature burst out of John Hurt's chest...
posted by PhineasGage at 9:22 AM on December 5


It doesn't appear to get mentioned in that article (I haven't clicked through all the links), but some of the data being used to investigate this was generated by a Raspberry Shake - a neat Raspberry Pi-based tiny seismology station. They pitch them for citizen scientists and up, they're pretty swell little devices.
posted by m2ke at 9:33 AM on December 5 [8 favorites]


My first thought was of course “Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn!”
posted by ricochet biscuit at 9:34 AM on December 5 [7 favorites]


I do wonder about how it is that no humans apparently felt anything wrong. That seems a bit unusual to me. Has anyone proffered a reasonable explanation for that?
posted by Alensin at 10:10 AM on December 5


Only one person noticed the odd signal on the U.S. Geological Survey's real-time seismogram displays. An earthquake enthusiast who uses the handle @matarikipax saw the curious zigzags and posted images of them to Twitter.

Whoever smelt it, dealt it.
posted by chavenet at 10:15 AM on December 5 [3 favorites]


k-day delayed by 5 years
posted by poffin boffin at 10:15 AM on December 5


Oooh, that Raspberry shake is cool! But expensive, $350 and up. The base kit is like $40; is the rest what a proper seismographic sensor costs? Or are they marking up the hardware?
posted by Nelson at 10:24 AM on December 5


Weren't there some very regular signals from Mount St. Helens before it blew? The so-called 'harmonic tremors'?

I remember them being hypothetically associated with magma moving up and down in simple harmonic motion in the throat of the volcano.
posted by jamjam at 10:48 AM on December 5 [2 favorites]


"Tremor" is a term for seismic energy that doesn't have a sharp onset -- harmonic tremor is a special case of this. A decade ago or thereabouts, people started detecting tremor associated with geodetically-detected slow-slip events on subduction zones like Cascadia -- and more recently subduction-zone tremor has been found to consist of multiple overlapping low-frequency earthquakes. This thing seems to be a low-frequency, shallow earthquake, but not a "slow earthquake" -- that term usually refers to slip events that are too slow to radiate seismic energy, and are detected mostly by geodetic instruments (GPS or strain meters). Unfortunately seismology's a bit jargon-y.
posted by irrelephant at 11:11 AM on December 5 [6 favorites]


> that Raspberry shake is cool! But expensive, $350 . . .

Er, cost of a seismometer is generally in the range $12,000-$20,000 so making this type of equipment available in the $350-$1000 range is more along the lines of "how can they possibly offer something this good at such an absolute rock-bottom inexpensive price" than "are the evil price gougers ripping us off AGAIN?!!??!1!!"
posted by flug at 12:21 PM on December 5 [4 favorites]


Your black-budget advanced weapons research dollars at work for you!
posted by Fupped Duck at 2:06 PM on December 5


Guerrilla marketing for a new Cloverfield movie, most likely.
posted by EXISTENZ IS PAUSED at 2:50 PM on December 5 [2 favorites]


I guess "undersea volcanic activity run through a natural low-pass filter" is the less interesting to some people...
posted by tobascodagama at 3:38 PM on December 5 [1 favorite]


I didn't mean to suggest anyone was price gouging in the highly lucrative amateur seismographic market. Just genuinely curious about pricing. When I heard "Raspberry Pi device for citizen data collection" I'm thinking "cool, if it's $100 I'll buy one!". The price of $350 surprised me a bit and made me wonder what a proper seismographic sensor costs.

Naively, a tiny little MEMS accelerator could be useful. How useful though, I have no intuition for. Guess it depends on sensitivity to small motions and accuracy. For that matter, does this $350 version have something to cancel out vibrations from larger things like cars and cats and clumsy humans?
posted by Nelson at 4:39 PM on December 5 [1 favorite]


Unfortunately seismology's a bit jargon-y.

My favorite seismology word is one that seismologists never use and newspapers invariably do because they can't think of any other synonyms for earthquake: TEMBLOR.
posted by the_blizz at 5:52 PM on December 5 [2 favorites]


Can't believe no one has tied this to Aquaman, out in cinemas December 14 /announcement
posted by cendawanita at 6:28 PM on December 5


Come, Gojira. Bathe this sick sad world in your purifying fire, and let us begin anew.
posted by Halloween Jack at 6:37 PM on December 5 [2 favorites]


Thanks for the science, Mr.Pointy.
posted by breadbox at 12:13 AM on December 6 [1 favorite]


Unnaturally simple signals sounds like measurement/instrument fault to me, but this registered on many different instruments? Very neat, thanks for the post.
posted by Made of Star Stuff at 5:27 AM on December 6


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