Quake Watch 2011

Magnitude 7.2 (Preliminary magnitude ? update expected within 15 minutes) CHILE
Date-Time Sunday, January 02, 2011 at 20:20:18 UTC
Sunday, January 02, 2011 at 05:20:18 PM at epicenter

Location 38.256°S, 73.570°W
Depth 33 km (20.5 miles) set by location program
Region OFFSHORE BIO-BIO, CHILE
Distances 96 km (60 miles) NW (305°) from Temuco, Chile
165 km (102 miles) SSW (196°) from Concepcion, Chile
174 km (108 miles) N (350°) from Valdivia, Chile
590 km (367 miles) SSW (205°) from SANTIAGO, Chile

Location Uncertainty Error estimate not available
Parameters NST= 10, Nph=0, Dmin=0 km, Rmss=0 sec, Gp=202°,
M-type="moment" magnitude from initial P wave (tsuboi method) (Mi/Mwp), Version=B
Source NOAA Pacific Tsunami Warning Center

Event ID pt11002001


UPDATE:
Magnitude 7.1 CHILE
Date-Time Sunday, January 02, 2011 at 20:20:16 UTC
Sunday, January 02, 2011 at 05:20:16 PM at epicenter

Location 38.360°S, 73.281°W
Depth 16.9 km (10.5 miles)
Region ARAUCANIA, CHILE
Distances 69 km (43 miles) NW (309°) from Temuco, Chile
160 km (100 miles) N (359°) from Valdivia, Chile
171 km (106 miles) S (187°) from Concepcion, Chile
589 km (366 miles) SSW (203°) from SANTIAGO, Chile

Location Uncertainty horizontal +/- 15.3 km (9.5 miles); depth +/- 2.1 km (1.3 miles)
Parameters NST=280, Nph=281, Dmin=352.9 km, Rmss=1.04 sec, Gp= 58°,
M-type="moment" magnitude from initial P wave (tsuboi method) (Mi/Mwp), Version=8
Source U.S. Geological Survey, National Earthquake Information Center:
World Data Center for Seismology, Denver

Event ID usc0000y49



earthquake.usgs.gov...


WHAT THE F.... !!!

2 DAYS... 2 Mag7 Earthquakes!

I dont know much about this stuff, but isnt it kinda strange to have two quakes over 7.0 in the same area two days in a row? Is this something to worry about?

reply to post by PatriotsPride


And... NO AFTERSHOCKS... ; )

reply to post by Austria

Yes, no aftershocks yet, but this time -- the quake being so shallow -- we are probably more likely to see aftershocks. However, they might not start at once. There could be a small delay while the various forces at work play out and likely produce some mag fives.

Mike

reply to post by Austria


The previous 7 was too deep to have any/many aftershocks... this one is shallower so we should see a few of them...

Could the big quake in Argentina have anything to do with the fact that our magnetosphere is getting hammered right now.


[atsimg]http://files.abovetopsecret.com/images/member/26c987d807a5.jpg[/atsimg]

This latest quake in the region is a shallow one compared to yesterday's event and should cause considerable damage to the affected area. The Hope, BC seismograph recorded the pwave and shows a noticeable upward motion.

Hope BC live seismograph

We'll have to monitor for aftershocks in the region.

Deez

reply to post by PatriotsPride


As far as same area, not really since this is a deep subduction zone. Argentina was deep and this was further up the down welling lithosphere, which if you subscribe to one theory could have been caused by the first one pulling down a piece of plate.

Last year there were two mag 7 in January, but not in the same area

Date/Time UTC,Latitude,Longitude,Magnitude,Depth(Km),Location
2010-01-12T21:53:10.000Z,18.45730,-72.53320,7.0000,13.0000,Haiti region
2010-01-03T22:36:28.000Z,-8.79980,157.36980,7.2000,25.0000,Solomon Islands

[atsimg]http://files.abovetopsecret.com/images/member/29631d7c8caf.png[/atsimg]

reply to post by MoorfNZ


You may not see that many if it is plate pull rather than a 'springing back' of a locked area. Just really depends on what caused it.

I was expecting something higher up the coast but not this!

reply to post by JustMike


Hats off to you Mike!!! You were dead on the spot with your call !!!! :u

earthquake.usgs.gov...

Okay, first aftershock of the 7.1 in Chile. A mag 5. About what we'd expect and not far off from the original epicenter.

Magnitude 5.0
Date-Time

* Sunday, January 02, 2011 at 21:10:19 UTC
* Sunday, January 02, 2011 at 06:10:19 PM at epicenter

Location 38.042°S, 73.531°W
Depth 26.6 km (16.5 miles)
Region OFFSHORE BIO-BIO, CHILE
Distances

* 109 km (68 miles) NW (316°) from Temuco, Chile
* 141 km (88 miles) SSW (197°) from Concepcion, Chile
* 197 km (122 miles) N (352°) from Valdivia, Chile
* 567 km (352 miles) SSW (206°) from SANTIAGO, Chile

Location Uncertainty horizontal +/- 28.6 km (17.8 miles); depth +/- 2.5 km (1.6 miles)
Parameters NST= 32, Nph= 33, Dmin=394.1 km, Rmss=0.91 sec, Gp=184°,
M-type=body wave magnitude (Mb), Version=5
Source

* U.S. Geological Survey, National Earthquake Information Center:
World Data Center for Seismology, Denver

Event ID usc0000y4w


Mike

EDIT: you must have beaten me to it by milliseconds with your post, Partiot's Pride! But I'll leave mine as is seeing as the link will drop off after a couiple oif weeks anyway.

A wee aftershock in Bio-Bio just now from that Chile 7.2...

(arrgh someone beat me to it )

How does the location/nature of this latest 7.2 relate to the biggie in Chile last year in which Bio-Bio also got a huge number of aftershocks?

reply to post by PuterMan


OK, Thanks for the info!!

think there will soon be a third strong earthquake!

reply to post by JustMike


The question is, is that an aftershock of the 7.1 or are they both aftershocks of the 8.8?

That area has never stopped rattling since and it could be argued that these are all aftershocks.

This is the activity in the area for the last 90 days

Date/Time UTC,Latitude,Longitude,Magnitude,Depth(Km),Location
2011-01-02T21:10:19.000Z,-38.04180,-73.53120,5.0000,26.6000,offshore Bio-Bio. Chile
2011-01-02T20:20:16.000Z,-38.35990,-73.28100,7.1000,16.9000,Araucania. Chile
2010-12-19T20:48:05.000Z,-34.71790,-71.66600,4.8000,52.2000,Libertador General Bernardo O’Higgins. Chile
2010-12-18T19:08:56.000Z,-34.17230,-71.97860,4.8000,28.3000,Libertador General Bernardo O’Higgins. Chile
2010-12-13T18:51:04.000Z,-33.92600,-72.96790,5.4000,18.9000,offshore Libertador O’Higgins. Chile
2010-12-11T21:22:49.000Z,-37.14970,-73.39080,4.8000,44.7000,offshore Bio-Bio. Chile
2010-12-07T15:33:46.000Z,-37.41180,-73.67640,4.8000,23.1000,offshore Bio-Bio. Chile
2010-12-01T10:01:44.000Z,-33.68450,-71.63330,4.9000,36.3000,Valparaiso. Chile
2010-11-29T11:56:37.000Z,-35.10370,-71.77790,4.7000,66.7000,Maule. Chile
2010-11-28T08:19:47.000Z,-34.52940,-71.63060,5.4000,35.0000,Libertador General Bernardo O’Higgins. Chile
2010-11-28T03:37:20.000Z,-33.88880,-72.27550,4.7000,28.4000,offshore Libertador O’Higgins. Chile
2010-11-25T03:27:30.000Z,-32.14170,-69.95200,4.9000,103.4000,San Juan. Argentina
2010-11-23T05:02:22.000Z,-31.17000,-70.43520,4.8000,99.6000,San Juan. Argentina
2010-11-20T02:09:30.000Z,-37.95310,-73.76380,5.2000,10.0000,offshore Bio-Bio. Chile
2010-11-10T01:23:33.000Z,-36.30940,-73.11830,5.1000,25.6000,offshore Bio-Bio. Chile
2010-11-02T10:38:25.000Z,-36.49120,-71.52960,4.7000,68.6000,Bio-Bio. Chile
2010-10-31T07:10:40.000Z,-33.67580,-71.92340,5.4000,25.6000,offshore Valparaiso. Chile
2010-10-25T07:45:20.000Z,-34.92370,-72.56350,4.9000,24.6000,offshore Maule. Chile
2010-10-23T15:47:40.100Z,-36.86000,-73.70000,4.7000,10.0000,OFFSHORE BIO
2010-10-23T15:47:40.000Z,-36.85080,-71.87320,4.7000,35.0000,Bio-Bio. Chile
2010-10-23T10:56:59.000Z,-36.71920,-73.43820,5.1000,28.9000,offshore Bio-Bio. Chile
2010-10-23T05:58:30.000Z,-37.76600,-73.47020,5.7000,35.0000,Bio-Bio. Chile
2010-10-21T04:45:43.000Z,-34.74210,-72.97370,4.8000,27.6000,offshore Maule. Chile
2010-10-21T02:49:55.000Z,-34.71380,-73.73770,5.8000,7.0000,off the coast of Libertador O’Higgins. Chile
2010-10-16T12:03:07.000Z,-34.98580,-72.13210,4.8000,32.9000,Maule. Chile
2010-10-11T08:35:31.000Z,-33.79820,-71.75010,4.9000,38.1000,Valparaiso. Chile
2010-10-08T07:21:02.000Z,-33.61190,-71.91810,5.0000,16.6000,offshore Valparaiso. Chile
2010-10-04T16:43:17.300Z,-36.38000,-73.45000,4.8000,30.0000,OFFSHORE BIO
2010-10-04T16:43:17.000Z,-36.30450,-73.29820,5.0000,37.6000,offshore Bio-Bio. Chile

reply to post by MoorfNZ


[atsimg]http://files.abovetopsecret.com/images/member/da94f664f587.png[/atsimg]

The big purple one is the 8.8

The green is Bio-Bio and the red is Araucania

reply to post by PuterMan


So can we safely say that this 7.1 is of the same ilk as the 8.8? Perhaps continuining aftershocks?

reply to post by PuterMan

Awfully hard question to answer. How long after a great quake do we still consider subsequent quakes as being aftershocks of that one? I doubt that there is any hard and fast rule; however, as this mag 5.0 has come within an hour of the 7.1 and is within the right location to be seismically related to it, I think it's fair to say that it's an aftershock of that event. If the 7.1 is an aftershock of the huge event from months back, then I wonder if we need to rethink the whole concept of aftershocks.

It could be worth considering.

Mike

reply to post by JustMike


Quakes are classed as aftershocks until the activity in the area of the mainshock is back to "normal" levels... (or a larger shock replaces it as a mainshock) Chile's been bouncing since the 8.8 and, given it was less than a year ago, I could see that these are still aftershocks...

reply to post by MoorfNZ

You so beat me to that one!

Activity has NOT returned to normal and these should ALL be considered as aftershocks.

@Mike - aftershocks can go on for years!

reply to post by MoorfNZ

Yes, I'm aware of that definition, but the problem is that it is really rather simplistic. The concept of "normal" in areas that are very seismically active is not so easy to quantify, I think.

The implication of "aftershock" is that the event is directly related to the previous, major event. While that is fair enough in some ways, it is still too simplistic. The cause-and-effect relationships can be very complex and in some cases almost impossible to determine with a high degree of certainty, so I feel that in regions like these, it is pushing the boat out a bit to state as if it's a given that a quake now is directly subsequent to -- that is, an aftershock of -- an event that occurred months ago further up the coast.

I mean, how far do we want to go with this? The largest quake in modern times occurred in the Chilean coastal region in 1960. If we apply our definition of aftershock, then all quakes since then (in that region) are aftershocks of that event, because there has not been one greater to replace it as the main event.

Of course, that would be an absurd argument if taken seriously.

For me, the problem is where stretching the time line goes from reasonable to the absurd.

Best regards and I need a damned drink. I'm suddenly very grumpy and it ain't you.

Mike

EDIT:
reply to post by PuterMan

Sorry, my friend but I don't feel it is realistic to apply the concept of aftershocks going on for years when the area is seismically active and the forces that cause these quakes, especially mega-thrust events, are not simply created there where the quakes occur but are pushing into the area from outside of it as the plates move (if we accept plate theory). Therefore, how can it be always correct to assume that years after a major event that released masses of energy, a new quake along that same fault system is an "aftershock" of the previous one, when the far more logical cause-and-effect point of view would show that the new quake could just as well have been caused by those forces that have been building up there for some time (even prior to that other quake) and therefore it is not an aftershock, but a new event with possibly quite different causation?

I think we're using a kind of "domino" theory where it's possible that there are actually several rows of dominoes that get knocked over by different hands.

By the way, you started me on this line of thinking. Thanks for that.

Mike