Swarm of earthquakes detected off Oregon (600 in 10 days)

Update:
MAP 4.0 2008/04/13 22:44:26 43.746 -127.523 10.0 OFF THE COAST OF OREGON

More information on Seismic Activity in the Pacific Northwest



image source: http://www.csc.noaa.gov/products/tsunamis/htm/images/quake/cascade2.gif


Cross section of the Juan de Fuca Plate subducting underneath the North American plate and the Pacific and Juan de Fuca Plates spreading apart from each other. U.S. Geological Survey.
image source: http://www.csc.noaa.gov/products/tsunamis/htm/images/quake/cros_s2.gif


This is about an earthquake swarm back in June 8, 1999:
Earthquake-induced changes in a hydrothermal system on the Juan de Fuca mid-ocean ridge


And another swarm in February 2005 (These older swarms look to be more north then the recent quakes):
Seismic Activity - Endeavour Ridge- February-March, 2005



image source: http://www.pmel.noaa.gov/vents/acoustics/seismicity/nepac/images/endev0205-locationmap.png


Geologic hazards of the Oregon coast

Written historic records from 1700 AD found in Japan confirmed geologic evidence that the Cascadia Subduction Zone can generate massive earthquakes.
image source: http://www.oregongeology.com/sub/earthquakes/images/japan-tiff.gif

reply to post by DearWife

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Funny how the original poster said there were no volcanoes near by, when my first though was Mt.St.Helens, then I thought about the caldera at yellowstone.

Nice post, love the graphics.

I was reading about something similar to this article yesterday:
Earthquakes Along The Cascadia And San Andreas Faults May Be Linked, Affecting Risk To San Francisco Bay Region



Cascadia subduction zone


image source: http://upload.wikimedia.org/wikipedia/commons/3/31/Subduction.jpg


image source: http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Cascadia_subduction_zone_USGS.png/420px-Cascadia_subduction_zone_USGS.png

reply to post by toasted

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You might want to re-read my Original Post as I was only quoting the AP article that said "there are no volcanoes in the area". Never said I agreed with it. I suppose it depends on what your definition of how close means "in the area", and how close the volcano's would have to be to be related to the quakes or not.

I believe the article was insinuating that since there's no volcano's right on top of the epicenter of the quakes they were stumped as they're only use to seeing this type of activity in the immediate vicinity of active volcano's. My initial reaction was maybe they better take a better look at the ocean floor there as they might discover something new.

That's why I asked for comments from experts or at least those in the know here. I too first thought (secondary to an unknown volcano) of Yellowstone and the rest of our Northwest volcano's after learning of this swarm, especially Mount St. Helens which I personally watched erupt live in 1980 from my childhood home.

Though I have no professional training or formal education to back my beliefs, unlike most geologist I believe all seismic events around the planet are more related then we are led to believe. Maybe it's just because there's not enough evidence yet, for them or their professors to come to that conclusion. I believe eventually that may change, but that's just my personal WAG.

As far as this having anything to do with an unknown 2012 event as one poster mentioned, that's a pretty big reach. Though I suppose with the pole shift going on it wouldn't surprise me if we had an increase of seismic related activity due to this pole shift.

Thanks everyone for sharing your knowledge & time in this thread, especially my DearWife for taking the time to bring the graphics here.


[edit on 13-4-2008 by verylowfrequency]

reply to post by verylowfrequency

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You sure know how to make a DearWife smile

Graphics do help with understanging things better, glad they were found and shared here for you all.

I was also thinking that it could be a new volcano forming like in the case of the new island in Tonga, but then there would be some evidence of pumice surfacing or gases. The link ressiv posted shows a Sea Surface Temperature graphic, which I also checked out on another website but the images state they're not availabe. They're the pics on the right under 3-day, click on either the 9km or 4km png (warning: huge graphics): SST [11 μ day] (Aqua-MODIS)

This is something interesting:
Storms uncover ancient 'ghost forest' along Oregon Coast



Oregon Coast Show - Neskowin Ghost Forest

YouTube Link

The Big One: Online Exhibit: Detective Story



image source: http://www.washington.edu/burkemuseum/earthquakes/bigone/images/trees.jpg


image source: http://www.washington.edu/burkemuseum/earthquakes/bigone/images/trees.gif


Hopefully there will be some news of what was found offshore with these recent quakes soon. A big yourwelcome to toasted and verylowfrequency on the graphics and thanks to the other posters for contributed to this thread as well. It's been a great learning experience. Think I'll retire now, hehe

In the case of Oregon, there are many faults, the subduction of the Juan de Fuca plate below the North American plate occurs just off the coast of Oregon, and historically this subduction zone sticks for a period of time and then slips generating some very large quakes (8+).

But what also happens as the crust subducts is remelting and volcanic activity that results, like that we saw with Mt. St. Helens. There has been an area of rising ground and earthquake swarms just east of the three sisters area, which indicates that it is likely a new volcano is forming there.

Like another poster here; I've had dreams all of my life with major re-working of the west coast and volcanic activity. I've also looked at the history of eruptions of pacific cascade volcanoes and it does seem when you look at the history that after one becomes active, such as St. Helens, that most of the other Pacific volcanoes do also within one hundred years, but Rainier is an exception to this; it appears to be quite independent.

The major subduction quakes haven't been marked by precursor swarms like this, this is more typical of volcanic activity, and given that there are other indications of same, I'm inclined to think that's what's happening.

[edit on 4/14/2008 by Nookster]

[edit on 4/14/2008 by Nookster]

Wow, i hope there's no tsunami from a large quake. They've happened
before...

Oregon Coast Tsunami

Thank you for the post. I've been watching the earthquake maps for a while now. I don't think people "in the area" should panic though. I'm in Portland and other than Mt. Tabor which is an extinct volcano, I don't think any of the volcanos are close enough to erupt on us.

If everyone would simply be aware, and watch for falling ash, we should be okay.

Id say its almost a necessity to learn about earthquakes and volcanos when you live in portland, or any part of the Pacific northwest which is close to lots of volcanos. One of which is still active (mt st helens) and the others, like Mt Rainier and Mt Hood are in active as of this time. Both are expected to blow at some point or another. Ive lived here for almost 11 years and have 11 years of studying geography and vulcanology(sp?) and evertything in between. For example, if you have ash falling, dont let it build up must more then a few inches or it'll collapse your roof. Afterall, it is pulverised rock! Needless to say, the swarm of quakes remind me so much of what Mt St Helens did before she started erupting again that in my opinion, I wouldn't be surprised if that boat comes back with gas and other measurements showing the movement of lava into a new volcano. I just hope that all of us here in Oregon are safe, and to remember, 3 days worth of food and survival tools is what they suggest for an earthquake or volcano, so all you peeps in the area, time to go shopping!

Im fascinated with volcanos and earthquakes, weird, I know, so this is a treat for me to see this in ATS!

Tela

reply to post by TwiTcHomatic

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Your dream may come true April 20, 2008. That is the full moon date and full moons + increase in ocean pressures + tempurature deviation + an upcoming coronal hole activity zapping earths magnetic field maybe all that is needed to set off a big one.

The geomagnetic coronal hole effect fits wrangell76 observations of auroras and sesimic activity.

[edit on 14-4-2008 by WorldShadow]

and we add one more prediction to the zillions here on ats...

I really hope that doesnt happen on April 20th. No offense, but I hope you are wrong.

I lived in Seattle in the 1990's and experienced quite a few earthquakes. We were very much aware of the seismic risk thanks to the great public information campaigns. I have always had a feeling that Rainer may go in my lifetime. I am fairly certain that Mt. St. Helens will erupt again. I spent some time doing botanical field work at Mount St. Helens when I was there and that was an awesome sight. Nature is in COMPLETE control is the feeling you get when you see something like that. The other thing at MSH is the life coming back and how it survived and spread out from areas where birds would land and poop or areas that were covered by 5 feet of snow during the blast.

The swarms do sound like a volcano, at least that is what "they" always say. Life is full of suprises.

Here's an update from National Geographic



image source: http://news.nationalgeographic.com/news/bigphotos/images/080416-oregon-quakes_big.jpg



This is from page 2:


NOAA Vents Program




[edit on 16-4-2008 by DearWife]

reply to post by DearWife

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Thanks again, DearWife. I'll look forward to the results of the 3 hour (day) tour. The weather started getting rough, the tiny ship was tossed....

Pretty cool that they have the resources to go out an do that so quickly.

Interesting sea floor picture as well.


[edit on 17-4-2008 by verylowfrequency]

Your welcome

Here's an update of that map:

image source: http://www.pmel.noaa.gov/vents/images/blanco-eqs-april2008.jpg


And this is an audio interview with one of the marine geologists whose working on this along with a sound clip of what the instrument picked up:
Earthquake Swarm Worries Oregon



Listen Now


Earthquake swarm puzzles researchers

Or it could have just been karaoke night for them whales and dolphins messing with them hydrophones.

EDIT: had to had some laughter

[edit on 17-4-2008 by WalkOn]

hehe...yes, that could of very well been what those clicking sounds were that were mentioned on the audio clip. Never know.

Several more quakes today already. Maybe we can get a new island in a few years.

reply to post by _Del_

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Looks to be magnitude 3's and 4's today.
Latest Earthquakes M3.0+ in the USA - Past 7 days

Here's an update from the NOAA Vents Program: