Quake Watch 2012

Doh, I'll let Puter have this one I'm clearly not quick enough. (beat me by a few seconds)

Things seem to be quite heated still. Hmm.

Crikey, another 6 ! (edit: I was going to say when is Vanuatu going to come back into the frame?, but didn't want to look like an idiot)
The seismic wave package hasn't arrived from Vanuatu yet on LISS SNZO at Sat 04/14/12 22:19 UTC, will probably be a decent sized one, S wave was due in at 22 14 40

I might as well leave USGS, GFZ and SNZO open or the day as watch the Planet crack open like an overboiled egg

FWIW
Sunda Strait (Java) looking like its down to 5.8Mw on the Body-Wave Moment Tensor Solution ITO (In Their Opinion)

Russians in at 6.1mb for Java
I'm glad I don't track mag 6-7's it would be a constant nightmare cross checking the networks, too many 6's go down below the threshold at usgs.
The only way to do it would be to just use mb, and forget Mw.



woo hoo yep, now thats what a 6.5 should look like

I'm still shaking my head. Everytime I check my graphs there's big wavy lines all over them. I've been watching daily for four years and I've seen nothing quite like this.

www.theweathernetwork.com...&stormfile=Are_earthquakes_becoming_more_frequent__13_04_2012

esciencenews.com...

On the earthquake map I use, last week there was about 100+ or so. I don't think it was 200. Now it shows 320.
It's not like it's keeping the pace it had when it first started rocking. But there still chiming in more regularly than they have, and they're popin up all over and in not so usual places. It's gotta calm down. Steady out. If it doesn't, then we really may have to rethink a few things.

I think the oregon traces are two different quakes. I like the idea that the double tap it the two different plates moving in opposite direction when they slip. Locations should demonstrate the moving provided they're accurate.

Originally posted by TrueAmerican
reply to post by JohnVidale

 

lol, funny. We get nearly identical signatures in nearly the same location, along the same divergent boundary, caused most probably by the same mechanism, and yet now all of sudden it's one quake instead of two?

I'm trying to follow along with this conversation, and just wanted to make sure you fellows were talking about this event.

If yes, what divergent boundary are you referring to? That quake is on the Blanco Fracture Zone, which is a transform fault zone--not divergent.
If you're talking about a different event, my apologies; and I am obviously confused.

reply to post by Olivine


I didn't say it was normal faulting, nor that it was two events, that was TA. I'd say one strike-slip event, as you say, on a transform. But that is the event we have been discussing.

I'll make it appear on the PNSN web page in a minute, so that you can see the waveforms and judge for yourself whether it is one or two events.

reply to post by JohnVidale


OK, it appeared on the PNSN map, but links back to the NEIC event page, where no waveforms are visible. But the focal mechanism is clearly determined as strike-slip

earthquake.usgs.gov...

and the location on the Blanco

neic.usgs.gov...

Hi John
I confused you with the way I used that quote. Sorry about that.
I was actually asking TA, since, as you pointed out, it was he who called it a divergent boundary.

Thanks for working with us.

reply to post by JohnVidale


Please do us a favor and listen to the sounds. Long ago, I read the insturments and Puterman could only hear them - as so he said. Now - I understand what he was saying as I have listened to his recordings of the earth speaking to us... listen to the Booms, learn them - it is important! listen to the fluids move - it is important! There is a differance between I don't know how to put this so I will do what I can with a visual = doctor taking a look on the outside with external visual observations vs. stethoscope listening to a heartbeat. --- Different waves are not going to produce separate Booms in the sound files (that we have experienced yet - that I am aware of)

PS BTW - Glad to have you aboard!

Another 6

Type: Earthquake
17 minutes ago
Magnitude: 6.1
DateTime: Sunday April 15 2012, 05:57:38 UTC
Region: off the west coast of northern Sumatra
Depth: 15.2 km
Source: USGS Feed

Source

Hm, 3 6 mags in 18 or so hours.

Soon enough they'll be referring to April 2012 as the tornado and quake outbreak month, or at least the first two weeks have certainly had it's hefty stirring of both.

So, 8.6 and 8.2 mag Indonesia, a 6.0 and several 5s and so on in that region. The 5.9 in Oregon and 6.5 in Mexico, to the 12th with the 6.2 and 6.9 in the Gulf of Cali then pause to the past 18 hours for the 6.2, 6.5 and 6.1.

I mean, looking back at those weeks last year where we had no 6s for stretches of time compared to all of this energy being spat out in 4 days.

reply to post by murkraz


7 x 6's in last 4 days, and 2 just under at 5.9...almost 2 a day over 6 mag.

I guess that it's better to have some regular 6's relieving stress, rather than that unusual quiet period leading up to those 2 x 8's!

Can i ask a few questions to the more knowledgable members.

When the two 8's happened off Indonesia, i kept hearing the term Horizontal slip being thrown about, which is a new one to me.

Now, are horizontal slip faults completely seperate to subduction zone faults? Or can a horizontal slip happen on a subduction zone fault?
If the latter is correct, if a horizontal slip was to happen in a subduction zone, could that put pressure/stress on a certain area of the subduction zone, possibly causing a stronger vertical subduction slip and tsunami, Such as the one in 2004?

My apologies if i have got any of the terms incorrect, i'm still learning.

reply to post by skitzspiricy

British Geological Survey seismologist Dr Susanne Sargeant says.

"Strike slip earthquakes are caused when two blocks move horizontally past each other. Such an earthquake would not lead to the vertical displacement of the sea floor that would be required to generate a tsunami. Consequently, the potential for a large tsunami from this earthquake is likely to be low," she said.

Megathrust earthquakes occur at subduction zones at destructive plate boundaries (convergent boundaries), where one tectonic plate is subducted (forced underneath) by another. The 2004 Boxing Day Sumatra quake & 2011 March 11 Japanese quakes were Megathrust's and generated tsunamis.

reply to post by SpaceJockey1


TY SpaceJockey

So were the big quakes on the 11th on a completely seperate fault? Or are they related to the subduction zone in that area?

reply to post by skitzspiricy


I don't believe you can have both strike-slip (horizontal or transform faults) and sub-duction (thrust faults) at the same location, although they may come together at some points and thats where it gets messy.
New Zealand is an example, where the subduction reverses from East under West (Hikurangi Margin) to Continental Transform (Alpine Fault) back to subduction again, but West under East (Fiordland Coast) this time.
The only other examples are the Dead Sea Transform fault, Pakistan's Chaman Fault, Turkey's North Anatolian Fault and North America's Queen Charlotte Fault
en.wikipedia.org...

reply to post by PuterMan

In my 'umble opinion I believe the Oregon off shore 5.9/6.0 was actually 2 with 58 seconds of separation and with 2 very small ones after that. The second one has never been reported as far as I can see, at least not on USGS.

Many Thanks sir for that explanation and that graph, that could have a lot of implication in the future recording of the earthquakes.

Did I not spot this one being reported? Apologies if so. (ETA: Oops - see you posted it Space Jockey, mind you would have known about it before the event anyway

)

Magnitude 6.2 off the west coast of northern Sumatra

Location in Google Maps

• Date-Time: Sunday, April 15, 2012 @ 06:57:38 UTC
  
• Earthquake location 2.549°N, 90.277°E
  
• Depth: 15.2 km ± 6.1 km
  
• Region: off the west coast of northern Sumatra
  
• Distances:
  651km (404mi) from Banda Aceh, Indonesia
  671km (416mi) from Sabang, Indonesia
  673km (418mi) from Meulaboh, Indonesia
  678km (421mi) from Sinabang, Indonesia
  1254km (779mi) from Colombo, Sri Lanka
  
• Mag Source: USGS National Earthquake Information Center
  
• Event ID: usc000941x
  

Derived from Data Source: USGS
Powered by QVSData


By the way I will leave this up as very late last night (5 am) I finished converting the part of QVS Data that produces these to the new USGS web site. A few minutes longer up and I would have caught the quake! The links go to the new data not the old.

reply to post by PuterMan


Hah hah!

While you're sleeping, we try to keep an eye on things...

reply to post by muzzy


Thank you for clarifying that for me Muzzy, and the Wiki page was an informative read. I ceretainly learn a lot in this thread, Thank you all for your combined work and knowledge.

Would those particular quakes on the 11th have an effect on the Subduction Zone in the area, i understand that they were quite a way away from the subduction zone that caused the megathrust in 2004? (please correct me if i'm wrong). But could these specific quakes have a knock on effect in that area, i.e. a build up of stress or a release of stress. Or would it not have any effect at all?

I know it's small. I only draw attention to this particular earthquake is because it proves a point.

earthquake.usgs.gov...

TABASCO, MEXICO. 4.6M
(i'm not shilling for tabasco sause)

This proves it's been a very hot and spicy time to be watching the quakes upon the plates.

I wouldn't have even noticed it except I was looking for something around 5UTC. I couldn't find it, but thought the Mexican quake was it for a moment.

Let's have a party if one goes off in Tequila.