Quake Watch 2011

reply to post by StealthyKat


It sounded like it was everywhere. I am in North County St. Louis, Missouri, 1 mile from the Missouri River by Alton, IL.

It was really loud. But I didn't know we had a gas pipeline anywhere near here. No gas, water or sewer out here due to the extreme sinkholes. Or cable, for that matter.

tmiddlebrook is back!

www.abovetopsecret.com...

reply to post by MamaJ


They removed it and said it was due to blasting. It was first listed at 2.5 I believe.

Yo there, I see its been quiet the last few days quake wise, I been in hospital, rushed in by ambulance on Monday night bleeding in the bowel from operation 10 days prior, all OK now but was pretty frightening.
No internet in there so was pretty boring.
Bit of catching up to do, maybe tommorrow.

Just had a quick look over whats been discussed last few days,
re the noise before a quake,
ABSOLUTELY
we get it from the Mag 4's in Cook Strait, you can sort of sence it before you hear it and its like a train coming, all this before any shaking. I've always put it down to the pressure in front of the P wave
What does P in P wave stand for ?

I did a job for a guy whose new house was built underground a few years back and we were working on the concrete slab roof and felt a 4.8 from Cook Strait come through. Afterwards we were talking about earthquakes and he said that being 10ft below ground level they always heard the quakes coming before there was any shaking, so they had time to brace themselves. Safest place I ever been in, 1ft thick solid reinforced concrete walls built like a bunker. Warm as toast too.

Originally posted by muzzy
Afterwards we were talking about earthquakes and he said that being 10ft below ground level they always heard the quakes coming before there was any shaking, so they had time to brace themselves. Safest place I ever been in, 1ft thick solid reinforced concrete walls built like a bunker. Warm as toast too.

Hmm, now how can that make sense? The speed of sound is no match for the speed of P or even S waves.

Speed of sound= 343.2 metres per second (1,126 ft/s). This is 1,236 kilometres per hour (768 mph), or about one kilometer in three seconds or approximately one mile in five seconds.

Speed of P waves= 2 to 8 km/s in the Earth's crust up to 13 km/s in the deep mantle.

Earthquake waves are much faster. So I don't understand how they can "hear" the quakes first.

reply to post by muzzy


Primary.

Sorry to hear you were in hospital.

No Internet

I am wondering if the 'sound' is because the waves are deflected as they travel. As we have said on the thread and TA mentions, seismic waves are fast - up to Mach 32 - but parts of the wave reflecting of angular surfaces could slow down enough to hear .

If that was the case they would get there earlier as the were in effect riding on a carrier wave.

Muzzy, glad to see your back. From the hosptial and from the past. I noticed you posted on Quake Watch 2010 again. Be well. And you've not misses much. Everyone is noting the quiet. I should note that we are midway through the lunar cycle and maybe this is a partial reason for the ebb.

Also, I am noticing that the eastern US is very quiet. Once again it is interesting that the quakes are clustering when they come, and the areas are quiet all at the same time. I suppose the best thing to do now is watch as the activity returns and see if there is another major cluster, or if they just pop up at random intervals. If there is a true pattern, we should fist see something out Colorado way, followed by some near Virginia within a short time-frame.

reply to post by muzzy


Hey Muzzy, good to hear you're ok and to see you back on here

anyone want to take a look at the LA quake cam?

abclocal.go.com...

was calm, now jittery

thought maybe storm or tide

here's LA weather
weather.cbs5.com...

reply to post by berkeleygal


I've had it up watching it too and I hope it isn't building into something larger.

reply to post by berkeleygal


I take it, based on the lack of the thicker black line on the top part of the cylinder, is what you are referring too?

Is the top half what it normally looks like?

I've been watching it for the last
hour or so, never have seen it
like this. Hope someone pops
in to tell us its just a glitch.

reply to post by radpetey
[mor

The flatter the line the calmer the earth is basically. It still could be showing waves from the Tonga quake earlier or another large quake, they can sometimes take a while to calm down even a few days. So it may be nothing to worry about at all.

reply to post by radpetey


yes to your first question

and, it changes, the other day there was a lot of activity, then it calmed down. I am not sure just what is causing the constant activity now.

reply to post by radpetey


I was concerned about the dark
band around the drum, with the
needle underneath in jittery
motion, almost constant.

reply to post by radpetey


Could be responding to larger, distant quakes.. they can wobble around for a bit. However it's gone on a long time considering the recent quakes weren't terribly big. We get a lot of "noise" on the Geonet drums here (NZ) and it can be due to construction work, weather etc. However, the weather doesn't look too bad for the area at the mo, at least not what I'd expext to see picked up on seismo.

reply to post by SusanFrey


Ya! your most likely correct.

I sure hope it is not harmonic in nature.....Or maybe the devil has his music up too loud this evening.

reply to post by radpetey


No we don't need any harmonics tonight but Puterman would be the best to check that out.

Here is a station for Albuquerque, NM it's showing it too some show it better than others.

folkworm.ceri.memphis.edu...

reply to post by PuterMan

Primary?
Hmmm could be, but I wondered why it didn't stand for "Pressure"
USGS explanation isn't much help but "compressional wave" does fit in with pressure.
My explanation about the sound of an earthquake is that the air in and around the rocks of the substrate is being disturbed or pushed out of the way by the shock wave, so the sound is air moving. This could also explain the sensing part of it too, as even the human body is sensitive to changes in air pressure.
I've always assumed this was a fact and have never bothered to check it out.
Same if it was gas

5.5 Eastern Turkey

Shallow

earthquake.usgs.gov...

70 km (43 miles) W of Erzincan, Turkey
123 km (76 miles) NNW of Elazig, Turkey
141 km (87 miles) E of Sivas, Turkey
500 km (310 miles) E of ANKARA, Turkey