New Activity at Mt. Rainier Confirmed to Be Seismic (...or ICE?), Right here on ATS!

reply to post by PuterMan


Thanks Puterman.

I read this short 5-page paper last night. Induced seismic activity by a glacier in volcanic areas found here--200 kb PDF

Basically, icequakes look like icequakes when they are shown on seismograms from seismometers embedded in the glacier--Asymmetric, impulsive front, short coda duration (

reply to post by Olivine


Well, that was a very important post.

The icequakes differ From LP events in all the analyzed parameters: signal shape, spectral content, spectrogram, wave front, duration, amplitude, S-P phases and particle motion. These differences are observable at the ice station but not at the bedrock station. No disperssion effects are observed for LP events.

Icequakes and LP events are practically identical in the data registered on the bedrock, such was observed by Weaver and Malene (1976) at Mount St. Helens. This suggest that it is essential to install a seismometer on the glacier to differentiate both kinds of events.

And interestingly, one of the very first things PNSN said was that they don't have either GPS or Seismic stations on the ice.

So now the question is, why not?

I could make a scathing political comment about right now, but I won't.

OMG this is killing me! I am working today (hip finally healed enough) so I can't get into this from my work computer and am limited to brief use on my phone!!! Figures.

I will post a bunch more in a few hours buthave to say this for now:

TA..I have no doubt that on a normal volcano you'd be right ..... like you, I greatly respect PM and have never seen him argue FOR HT. You have a very valid point about.the hz of the on going quakes.vs this odd sig but remember this:

The hz of the ice quakes are going to be attenuated LESS because they are shallow and.occiring on the ice. OF that is more HT than its origin is deeper and of different matter so its attenuation will be further distorted by the ice.

Am I making sense?

I gotta go but will try to send off an email to oneness but I'm limited on my access.

reply to post by TrueAmerican


I here ya, TA. I was just going to make a post asking who we need to write,e-mail, bombard to demand a temporary array on a few of the glaciers during this "swarm".

TrueAmerican, did you also read the part saying that the amplitudes are 10x's higher for the events when registered on the ice? So, basically, yeah, the ice/rock interface on Rainer is attenuating the signals...

Oh my goodness. Autocorrect is killing me and I can't seem to edit.

Hope it made sense. And I wrote pnsn NOT oneness.

reply to post by westcoast


LOL @ "oneness". We'll be here when you can get away from your real world demands. I look forward to your posts, WC.

I just wanted to add, I believe the S. Malone, sited in the above paper is the Steve Malone that works at PNSN/USGS/UW referenced in blog posts on the PNSN site.

Originally posted by Olivine
reply to post by TrueAmerican

 

I here ya, TA. I was just going to make a post asking who we need to write,e-mail, bombard to demand a temporary array on a few of the glaciers during this "swarm".

How do you even know about temporary arrays? lol. You scare me you know so much. For a fricken Botanist!

But yes, my question exactly. For example, when we had a swarm that developed in CA a year ago or so, I got in touch with some people at Berkley. Through email exchanges I learned that they had dispatched a temporary array to the area for better study. And I know from reading other things that many networks keep temporary arrays in stock for just that kind of occurrence. Why they wouldn't have better coverage for a situation like Rainier, a known active beast, threatening a lot of people, remains beyond me.

Although I will mention a certain comment made to me that said something on the order of "It's very hard to work up there at those elevations."

And it is. A lot of people get their butts in a sling or dead trying to mess with that mountain. The wind, the ice, the snow- yeah, has to be a bitch. But darn, drop a homemade wireless sensor on a glacier or two from a helicopter, I don't care. Just get the thing covered is what I am saying... And I don't even live there.

TrueAmerican, did you also read the part saying that the amplitudes are 10x's higher for the events when registered on the ice? So, basically, yeah, the ice/rock interface on Rainer is attenuating the signals...

Yes, Ma'am.

The attenuation is very high, and even more of a reason they need better coverage. Scientists are not usually like this. If there is a step that can be taken to further qualify data, they will usually make sure it happens. So gotta be something else going on. Lack of funds is probably part of the problem, but I am just speculating.

Originally posted by westcoast
...but remember this:

The hz of the ice quakes are going to be attenuated LESS because they are shallow and.occiring on the ice. OF that is more HT than its origin is deeper and of different matter so its attenuation will be further distorted by the ice.

Am I making sense?

Well in a sense yes, you are making sense, but also we must consider the issue of the huge fissures and crevices at very shallow depths then too. Because I repeat: Any shallow crevice or fissure will stop both P and S-waves dead in its tracks, if there is enough of a gap. And look at some of those pictures. Some of those cracks are HUGE. Ain't no WAY no seismic wave is going to propagate through them.

And so what could that mean? That these ice quakes may be deeper than they think. They already said they cannot identify separate P/S waves.

But if nothing else, this thread was absolutely worth the effort. Because we have identified a potential problem in the monitoring- actually two. Lack of better frequency response coverage, and lack of GPS/Seismos on the ice itself.

What this thread thus reveals is that someone, somewhere, had better start asking that the UW be better provided for. Lives are at stake.

Response was that yes, it IS odd and they will confer without the experts. I'll let you know....I'll be at home soon too. p

ok, seriously, I am not liking at all what I am seeing here at STAR in the last while.

PuterMan, have at it. Cause I don't like that frequency content, OR the webicorder view, and I very seriously doubt that is wind noise with that frequency content. I'd say that looks like tremor, not harmonic, but please have a look. Pull STAR data for the last while.


ETA: The amplitude is larger than background noise it seems, yet hot in all the right frequencies. Could be the dynamic spectral though, but not sure.

reply to post by TrueAmerican


TA, just from looking at it in GEE, I was having the same thoughts.

I was going to wait on posting my last resposne since I am still waiting for confirmation and more info, but it was suggested that what we saw was possibly a helicopter that had been up looking for four lost hikers yesterday. They are going to check with the park to see its likely or not.

I'm not giving an opinion on this yet.

Also TA...not to insult you at all because I am sure you know what wind looks like but we are under a high wind watch right now, just FYI.

ETA: Here is the LINK showing an example of a helicopter. (I think Olivine provided this awhile back) I gotta say that at least this one doesn't look at ALL like it, IMO.

reply to post by TrueAmerican


I can't see anything wrong with STAR as such. At about 23:30 there is a bump and grind (small) and from 00:00 just background noise that does not look particularly interesting.



BTW that RCS gliding sound appears in 2 other places during the day but not quite as strongly.

TA, I'm glad you posted this. I've wanted to ask about the increased "background noise" for the past hour or so, but haven't because I was certain you would say it was wind.
(btw, I checked wind speeds, and they aren't that high; about 35 mph maximum at 5600' elevation.)(about 4 hours ago)

Check out CC. OBSR. BHZ , if you have a moment. The amplitudes have come down a bit (+9/-18 microns/sec currently. It was at +20/-30 mic/sec.) And it's much further down the mountain. I honestly hope all this noise is wind/rain/snow.

@westcoast--ah, so it is high wind. I feel much better.

@Puterman, just wanted to say I thoroughly enjoyed listening to your sound files this afternoon. They are both scary and pleasurable at the same time.

reply to post by westcoast

helicopter

:shk: :shk: :shk: :shk: :shk: :shk:

helicopter......schmellicopter. Never in a month of sundays does a helicopter make a gliding sound like that at 11 Hz. Nor does a helicopter take 6 minutes or more to do a pass, and if it was hovering the sound would not vary.

* shrugs and walks off to bed *

(Of course I could be wrong - nah perish the thought)

ETA: Last thought before I close down. The helicopter signal they show looks like a shortened version of the trains, which is exactly what I would expect, and the trains sounded NOTHING like this sound. The harmonic may be from the glacier. I am not saying it is magmatic HT, but HT it is.

Night all.

reply to post by westcoast


It's interesting, cause on one hand it does look like wind noise on the webi some, but in spectral, I am getting frequencies showing that shouldn't be there, not on a dynamic spectro, but still unsure. More growing pains.

Originally posted by westcoast

ETA: Here is the LINK showing an example of a helicopter. (I think Olivine provided this awhile back) I gotta say that at least this one doesn't look at ALL like it, IMO.

edit on 24-1-2012 by westcoast because: (no reason given)

It wasn't me, but Radpetey.

I'll have to check later to see if you all have solved the riddle of this mountain. My brain is mush and my beloved Capitals are battling the Bruins...

Here is a response from Mr. Vidale in answer to a question on the blog site. I think it confirms some of the earlier speculation about a lack of equipment/etc:

Yes, snow and ice slumping on the glacier both increase the force driving it down the mountain and increase the clamping from the added weight. We call those shear and normal stresses, respectively.

We wish we had some GPS measurements, or a series of photographs to watch surface movement, but alas there are no useful measurements of the long-term motion at the necessary resolution.

source

ETA: oh, and PM. I hear ya.

Yep, pretty sure it's this darn spectro-thingy getting me again. On one hand I hate it, but on the other, I love it. Because I am now just realizing that one very quick way I could tell if it was magmatic HT, is if the frequencies persisted while the microquakes are occurring. And they don't. Now sorry if that confuses, but it just made all the sense in the world to me. Like getting smacked upside the head. Ok, alarm off.

And now I also see that the amplitude of the microquake has to be enough to overcome and suppress the background noise floor.... Hmm, very interesting indeed. So at a certain count level threshold, which I have yet to pin down exactly, I would instantly be able to tell I think if HT became present. Cause if the quake amplitude is pinning the noise floor, and yet I still get heavy amplitudes at 2-10 Hz, THAT's when it's time to call woof woof.

Anyone bored yet?

Hey guys and gals.....Is this a wind signature or something else on the RCM seismo?

old.pnsn.org...

Originally posted by radpetey
Hey guys and gals.....Is this a wind signature or something else on the RCM seismo?

old.pnsn.org...

edit on 24-1-2012 by radpetey because: forgot to post link.

here is the power spectra for what is happening at RCM:



If that were HT, we'd see a big bump between about 2 Hz and 6 Hz, maybe a bit higher. And as you can see it is not there. So my best guess is no, and yes, wind noise.