Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: LeeE on 27/02/2010 13:15:59

Title: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: LeeE on 27/02/2010 13:15:59
The USGS Google Earth Quakes plugin shows the quake as 8.8 and was centered just about 5km offshore, and about 35km deep.

Looks like there have already been a slew of 5's & 6's (up to 6.9) N & S of it.
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: geo driver on 27/02/2010 20:24:45
bbc confermed 8.8. 
65 dead at the moment coastal folk told to run for the hill if there are more aftershocks

how deep was this quake and what sort of "'waves" did it produce?  as damage seems to be minimal for such a huge one?
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: JimBob on 27/02/2010 22:27:40
8.8 magnitude
Location 35.846°S, 72.719°W
35 km (21.7 miles) set by location program

It produce ALL of the types of earthquake waves that  you could imagine. For aq lit of them see Wikipedia - http://en.wikipedia.org/wiki/Earthquake_waves



http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/us2010tfan.php
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: JimBob on 27/02/2010 23:17:59
I have been monitoring the USGS earthquake center's website for aftershock information - and look at this!

Oklahoma, mid continent region. US, North side of Anadarko Basin

Earthquake Details
Magnitude   4.4
Date-Time   

    * Saturday, February 27, 2010 at 22:22:27 UTC
    * Saturday, February 27, 2010 at 04:22:27 PM at epicenter
    * Time of Earthquake in other Time Zones

Location   35.623°N, 96.762°W
Depth   3.8 km (2.4 miles) (poorly constrained)
Region   OKLAHOMA
Distances   

    * 5 km (3 miles) ENE (74°) from Sparks, OK
    * 9 km (6 miles) S (179°) from Davenport, OK
    * 15 km (9 miles) SE (130°) from Chandler, OK
    * 72 km (44 miles) ENE (77°) from Oklahoma City, OK
    * 314 km (195 miles) N (0°) from Dallas, TX

Location Uncertainty   horizontal +/- 14.1 km (8.8 miles);
depth +/- 3.8 km (2.4 miles)
Parameters   NST= 61, Nph= 68, Dmin=72.1 km, Rmss=1.48 sec, Gp= 65°,
M-type="Nuttli" surface wave magnitude (mbLg), Version=7
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: JimBob on 28/02/2010 01:15:30
Not much guessing as to what cause the Oklahoma, earthquake. The picture below shows the location in the cross-hairs. The red lines parallel the river, which follows a fault system. The earthquake was centered only 12,700 feet underground.

The river is the Canadian River. As most of you know, rivers usually meander all over the place in graceful curves, as in the left of the picture. The faulting changed all of that.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi38.photobucket.com%2Falbums%2Fe111%2Fgeezer69%2FOklahomaquake.jpg&hash=f800ae645c6fbe32967536710e10fafc)

Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: Karen W. on 28/02/2010 07:33:43
We have had Tsunami warnings all day... I haven't heard anything more over the last few hours. Does anyone know what the tsunami warnings were rated at for my area... and how long we need to be watching... I have been occupied by the death of another friend today and have not been able to get details... I just cannot believe how bad this quake was .. good grief. Thats terrible.
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: LeeE on 28/02/2010 12:16:07
Still lots of aftershocks occurring, including a 6+ within the last hour of this post.

I'm Just curious why the thread title was changed.  It seems a bit daft if it was just to turn it into a question, seeing as its global news and a clearly established fact.
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: Karen W. on 28/02/2010 21:28:01
All threads Must be in the form of a question.. it for search engines etc..

Thank you though for the information.
My daughter read or heard something about 10 ft swells was all they expected here .. double what I had heard..
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: geo driver on 28/02/2010 22:23:43
just looking at the rest of the river is that all fault?  there seems to be alot of straight lines is some of that cannal or just the way it is
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: JimBob on 01/03/2010 01:09:24
just looking at the rest of the river is that all fault?  there seems to be alot of straight lines is some of that canal or just the way it is

The Canadian River is what looks like a canal where it parallels the red lines. Look up these coordinates on Google Earth or World Wind - 35.623° N, 96.762° W
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: geo driver on 01/03/2010 22:20:15
i was looking at it form google earth. go 6km east and 6km north i saw a massive straight line and thought it was a canal.

the more i look at the behavior of this beautifully savage world the more im in love with it
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: geo driver on 01/03/2010 22:24:09
bbc confermed 8.8. 
65 dead at the moment coastal folk told to run for the hill if there are more aftershocks

how deep was this quake and what sort of "'waves" did it produce?  as damage seems to be minimal for such a huge one?
i take it all back the damage was not minamal
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: Madidus_Scientia on 02/03/2010 11:26:13
The earthquake has actually made our days shorter by 1.26 microseconds, since it has shifted mass inwards. So like a spinning ice skater pulling their arms in, earths rotations has fastened http://www.businessweek.com/news/2010-03-01/chilean-quake-likely-shifted-earth-s-axis-nasa-scientist-says.html
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: Bass on 02/03/2010 16:42:03
Similar to Chile, the Pacific northwest (Portland, Seattle, Vancouver) also sits above a convergent subduction zone, with past very large (9.0+) earthquakes and tsunamis.  The destruction will be far worse due to population density when the next earthquake eventually strikes this area.
Title: Re: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: frethack on 03/03/2010 17:54:44
I thought this was pretty amazing.  The photo below is of the night sky in Chile about 24 hours after the quake.  Upon first seeing the stars, I thought that this must have been an hour long exposure showing the Earths rotation, but the photographer states that it is an 88 second exposure.  The wobble in the stars is from crustal movement  [;D]

Anyway...heres the photo
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.spaceweather.com%2Fswpod2010%2F03mar10%2FColin-Legg1_strip.jpg&hash=228cdba2fa1ab21fe34036e68c9d56a4)
Title: Was there a large earthquake in Chile today?
Post by: Bass on 03/03/2010 18:07:03
COOL photo!

Amazing that the landscape is so sharp if the camera was jiggling about.  I wonder if the direction and size of movement could be calculated using the exposure time, length of the "jiggle" in the stars and their direction.
Title: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: frethack on 03/03/2010 21:47:59
The article and photo are from www.spaceweather.com ...great site btw
Title: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: LeeE on 04/03/2010 15:03:01
That is a pretty amazing photo - ta for posting it.
Title: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: Bass on 09/03/2010 23:57:01
Interesting research from the Helmholtz Association of German Research Centres:

Earthquake in Chile -- a complicated fracture
A jumping rupture process

The extremely strong earthquake in Chile on 27 February this year was a complicated rupture process, as scientists from the GFZ German Research Centre for Geosciences found out. Quakes with such magnitude virtually penetrate the entire Earth's crust. After closer analysis of the seismic waves radiated by this earthquake during the first 134 seconds after start of the rupture, the researchers came to the conclusion that only the region around the actual epicentre was active during the first minutes. In the second minute the active zone moved north towards Santiago. After that the region south of Concepción became active for a short time. This rupturing trend agrees well with the distribution of the aftershocks during the following three days, as observed by the GEOFON-measuring network of the GFZ up to 03.03.2010.

In the year 1960, the strongest earthquake measured at all to date, with a magnitude of M=9.5, had its origin at Valdivia, south of the region affected now. "The quake of 27 February connects directly to the rupture process of Valdivia", explains Professor Jochen Zschau, Director of the Section "Earthquake Risk and Early Warning" at the GFZ. "With this, one of the last two seismic gaps along the west coast of South America might now be closed. With the exception of one last section, found in North Chile, the entire earth crust before the west coast of South America has been ruptured within the last 150 years."

The underlying plate tectonic procedure is such that the Nazca-Plate as part of the Pacific Ocean Floor moves eastwards with approximately seventy millimetres per year, collides with South America and thereby pushes under the continent. The hereby developing earthquakes belong to the strongest world-wide. In the course of about one century, the Earth's ruptures completely in a number of strong quakes from Patagonia in the South to Panama in the North. Even Darwin reported, in his diary, of the strong earthquake in Concepción on 20 February 1835 and the resulting Tsunami.
Title: What do we know about the large Feb 2010 Earthquake in Chile?
Post by: LeeE on 10/03/2010 15:40:22
It's been widely reported (on the BBC at least) that much of southern South America was laterally shifted as a result of the quake.  GPS measurements show that Concepcion has been moved by about ten feet and that even the Falkland Islands, off the East coast of Argentina, were shifted (I've not yet seen a measurement for them though).