Quake Watch 2012

www.postcrescent.com...

www.washingtonpost.com... 2/gIQA9s6SUS_story.html?tid=pm_national_pop

www.npr.org...

So, the first shaking and booms were on Sunday. The USGS has the only recorded quake showing up on Tuesday the 20th. The booms were reported still happening yesterday.

www.youtube.com...#!

This is a common theme over the last few years. The ground is shaking and booming. Residents at standing room only town hall meetings. This is the script for a sci-fi movie. Oh wait, I've already explored this theme and posted the town hall from Jaws several times before. Oh how I forget things.


www.youtube.com...

www.youtube.com...

OZ gets its biggest one ...

www.stuff.co.nz...

Sorry. Old news.

reply to post by Olivine


Mm, same signature is turning up at Clintonville, Wisconsin. See this thread.

www.abovetopsecret.com...

That was a single thump, but the shape of the spectrogram is almost identical - high @ 15 Hz centre and nothing in the bottom end.

This gets more and more curious.

reply to post by PuterMan


Sorry about taking so long to get back to you, PM.
The length of the entire seismo pic above is about 5 min 50 seconds. And from the beginning of the 1st "boom" to the beginning of the second is 2 min 25 sec. So, a minute 40 second grab for one event seems right. Hope that is helpful.

It does look similar to the sonic boom signatures. I haven't listened to the sound file yet. I'm leaning toward the cause being manmade just because it would've been on USGS after being picked up by so many stations, if it was EQ. Coupled with the 15hz strength...it is odd. Thanks for looking into this.

reply to post by muzzy


Thanks for this nice summary of the Oaxcaca earthquake, Muzzy. Really fine work, Sir.

I hadn't heard there were fatalities. So sad. If this event had been closer to Mexico City it would have been devastating.

reply to post by Olivine

Thanks Olivine, glad someone found the info useful, sometimes you wonder if anyone reads the stuff I do.
I notice you didn't have a look at the 72hoursAftershockTimelineGraph page though
Actually no one has yet
Blog Stats show 4 people looked at the 30daysAftershockTimelineGraph page yesterday, maybe I'm focusing on the wrong time period.
I chose 72 hours because the graph fits on the page in thumbnail size but you can still see whats on it without opening each graph.
I've now added the 2010 Chile 8.8, 2009 Dusky Sound 7.8 and the 2008 Sichuan 7.9 graphs.

Not many graphs yet, the object is to get an idea what the aftershock sequences might be for any given area.
A lot probably depends on the source of the data, as it usually does, ANSS are not too bad, but tend just to go above Mag 4 (the Sichuan being the exception , down to 3.4). As a test did one for the SW of Siberia 6.8Mw quake last month using both RAS (Russian) and ANSS data, ANSS had 4 more quakes in the 72hr period, which surprised me, I expected it to be the reverse.
Of the 3 NZ ones I have done, there seems to be a thin scattering of 4s,and 5's then a time lag of 24-36 hours before the lower magnitude aftershocks kick in.
Chile and Mexico the volume of aftershocks is quite low, even the Chile 8.8. (Baja the exception)
For the Dusky Sound graph I did 2 versions, one based on the data I downloaded at the end of 2009 and one using the data downloaded yesterday ( 3 years after) and the volume of aftershocks listed was almost double (409 vs 720) so it may pay to be patient and hold back on drawing up conclusions early after the event.
I need to do more to get a better overall understanding.



Not that I'm looking for hits
I started my blogs long before I came on ATS, and I do a lot of the pages for my own satisfaction (like SNZO), if other people find it useful then thats great. I had a message on my NZ Historic Quakes V.1 blog from someone who remembered the Hawks Crag (Westport) quakes of 1991 when she was 3 years old, thanking me for putting up the maps and text on them as there was nothing else she could find on the internet. That was satisfying.

poorly constrained

Magnitude 4.4(4.9)

Date-Time Saturday, March 24, 2012 at 20:47:15 UTC Saturday, March 24, 2012 at 10:47:15 AM at epicenter Time of Earthquake in other Time Zones

Location 19.884°N, 155.138°W

Depth 16.7 km (10.4 miles) (poorly constrained)

Region ISLAND OF HAWAII, HAWAII

Distances 3 km (2 miles) WNW (303°) from Honomu, HI 6 km (4 miles) NNW (327°) from Pepeekeo, HI 11 km (7 miles) NNW (337°) from Papaikou, HI 21 km (13 miles) NNW (345°) from Hilo, HI 322 km (200 miles) ESE (119°) from Honolulu, HI

Location Uncertainty horizontal +/- 1.6 km (1.0 miles); depth +/- 22.7 km (14.1 miles)

Parameters Nph= 66, Dmin=35 km, Rmss=0.23 sec, Gp=202°, M-type=duration magnitude (Md), Version=1

source(earthquake.usgs.gov...

Magnitude 3.6 -
WASHINGTON 2012 March 24 21:16:18 UTC

Details Summary Maps Scientific & Technical Earthquake Details

This event has been reviewed by a seismologist. Magnitude 3.6 Date-Time

Saturday, March 24, 2012 at 21:16:18 UTC
Saturday, March 24, 2012 at 02:16:18 PM at epicenter
Time of Earthquake in other Time Zones Location 48.338°N, 122.272°W Depth 8.5 km (5.3 miles) Region WASHINGTON Distances 4 km (2 miles) NW (311°) from Lake McMurray, WA 5 km (3 miles) E (93°) from Conway, WA 7 km (4 miles) SSW (203°) from Big Lake, WA 10 km (6 miles) SSE (156°) from Mount Vernon, WA 79 km (49 miles) N (3°) from Seattle, WA Location Uncertainty horizontal +/- 0.3 km (0.2 miles); depth +/- 0.7 km (0.4 miles) Parameters Nph= 39, Dmin=13 km, Rmss=0.26 sec, Gp= 47°, M-type=local magnitude (ML), Version=2 Source Pacific Northwest Seismic Network Event ID uw60404846

Link:USGS

That makes me nervous. Hope it is just a small shaker and all goes quiet.

Something in the South Pacific 22:30ish UTC none of the networks have ID'd. Looks like a 5.
Could be South Sandwich Islands but that probably wouldn't show over here.
Can see it on Palmer the best, also
SNZO; TRQA, Argentina;
SBA, Scott Base, Antarctica;
RAR, Rarotonga, Cook Islands
AFI, Afiamalu, Samoa
LISS Global

Nothing on IRIS

happened before the Northern East Pacific Rise, so its not that one.

USGS details page

Magitude
5.1
Date-Time
Sunday, March 25, 2012 at 01:05:35 UTC
Saturday, March 24, 2012 at 04:05:35 PM at epicenter
Time of Earthquake in other Time Zones
Location
54.586°S, 135.802°W
Depth
10.1 km (6.3 miles)
Region
PACIFIC-ANTARCTIC RIDGE
Distances
2146 km (1333 miles) NNW of Mt. Siple, Antarctica
2211 km (1373 miles) W of Swain's Island
3311 km (2057 miles) S of ADAMSTOWN, Pitcairn Islands
3880 km (2410 miles) SE of WELLINGTON, New Zealand
Location Uncertainty
horizontal +/- 29.9 km (18.6 miles); depth +/- 2.7 km (1.7 miles)
Parameters
NST= 74, Nph= 75, Dmin=>999 km, Rmss=1.18 sec, Gp= 65°,
M-type=body wave magnitude (Mb), Version=6
Source
Magnitude: USGS NEIC (WDCS-D)
Location: USGS NEIC (WDCS-D)
Event ID
usc0008pp5

This seems bigger than a Mag 5.1 judging by the size of the surface waves hitting all the seismos I was watching in the PNW. It's making a mess of things the way a Mag 6 does.

ETA: Nevermind, I guess I was seeing the Mag 4.6 & 4.7 quakes from Mexico--they just hadn't been listed yet.

reply to post by Olivine


nice. : )

thats one part or the ridge that rose to sea level and then subsided.

the rumblus amongus.

were there any prior quakes in that area?

reply to post by omegacorps


Last one was in 2011 Nov.

lost site I found this on Will find again

Found it:thewatchers.adorraeli.com...

TextSunday March 25 2012, 03:59:10 UTC 34 minutes ago Central East Pacific Rise 4.8 10.0 CSEM-EMSC Feed Detail

Text

Sunday March 25 2012, 03:59:09 UTC 34 minutes ago central East Pacific Rise 4.8 10.1 USGS Feed Detail

quakes.globalincidentmap.com..." target="_blank" class="postlink">
quakes.globalincidentmap.com...



Oops Sorry about that

Starting to form a pattern? I mean the last three I posted

Saturday March 24 2012, 23:03:05 UTC 5 hours ago Northern East Pacific Rise 4.5 10.0

quakes.globalincidentmap.com..." target="_blank" class="postlink">
quakes.globalincidentmap.com...

reply to post by azureskys


That quake was 452 km from the epicentre of the last one so if you include a 500 km radius from the epicentre you find that it was far from the last one, which was 16th March 2012 - a 4.9 (448 km from the current epicentre)

Results for 500km
The USGS Circular search page

reply to post by azureskys

Starting to form a pattern? I mean the last three I posted

Last 2 don't you mean? The first post both are the same quake. Pattern? No these are possibly the result of the Oaxaca quake relieving a bit of stress despite the fact the the southern one is 1594 km from the northern one and both are a considerable distance from Oaxaca. With 2 quakes I don't see a pattern personally.

5.1, 2012/03/25 01:05:35, -54.586, -135.802, 10.1, PACIFIC-ANTARCTIC RIDGE, 3883 km (2412 miles) SE of WELLINGTON, New Zealand
4.8, 2012/03/25 03:59:10, -4.053, -104.245, 10.1, CENTRAL EAST PACIFIC RISE, 2714 km (1686 miles) W of Guayaquil, Ecuador

earthquake.usgs.gov...
Based on the traces on LISS SNZO that USGS 5.1 looks more like a 5.5-5.6 IMO.
Also the one on the graph with the P wave at at 22:32 I mentioned previously is probably in the same area is probably a 5.1, based on the comparitive size of the Central East Pacific Rise on the graph at 04:36 being a 4.8

Can't cross check with Geofon, is off line right now.

reply to post by muzzy

based on the comparitive size of the Central East Pacific Rise on the graph at 04:36 being a 4.8

The 5.1 is as the crow flies 3882 km from SNZo and the CEPR one is 8950 km ATCF. Is it possible to make such a comparison with such a huge distance disparity?

Would the 4.8 even show at SNZO? I know the 4.5 on the 24th is smaller and just over 1000 km further but how does that compare?

SNZO.IU.00.VHZ.2012.085 just out of interest or BHZ? You can hardly see it. SNZO.IU.00.BHZ.2012.085. I still want to know how they produce those LISS plots since they seem to have not relation to other ones. Something to do with the filters I guess.





SNZO.IU.00.VHZ.2012.084 Any ideas n the one that starts about 22:30? I had a look on your SNZO page for yesterday but it was not there - DUH I am being stoopid. That is the one you were pointing out above. Just ignore me.

based on the comparitive size of the Central East Pacific Rise on the graph at 04:36 being a 4.8

Sorry Muzzy I am not seeing that one as the CEPR. I believe it is another local one. Reasoning is thus:

CEPR 03:59
Trace 04:36
Distance of CEPR quake to SNZO 8960 km (I don't believe it would show)
This gives @ 36 minutes = 2160 seconds a P-wave velocity of only 4.14 km/sec which I feel is too slow.