Cascadia MegaThrust Fault Goes Active

Magnitude
4.4
Date-Time
Tuesday, March 08, 2011 at 07:19:33 UTC
Monday, March 07, 2011 at 10:19:33 PM at epicenter
Location
44.335°N, 129.250°W
Depth
10.3 km (6.4 miles)
Region
OFF THE COAST OF OREGON
Distances
409 km (254 miles) W (272°) from Yachats, OR
411 km (256 miles) WNW (287°) from Barview, OR
412 km (256 miles) W (270°) from Waldport, OR
490 km (305 miles) W (276°) from Eugene, OR
537 km (334 miles) WSW (258°) from Portland, OR
Location Uncertainty
horizontal +/- 21.5 km (13.4 miles); depth +/- 0.4 km (0.2 miles)
Parameters
NST=169, Nph=171, Dmin=476.4 km, Rmss=1.25 sec, Gp=169°,
M-type=body wave magnitude (Mb), Version=4
Source
U.S. Geological Survey, National Earthquake Information Center:
World Data Center for Seismology, Denver
Event ID
usb0001qp1

OK, now the pros come in. Great analysis of the Arkansas seismic activity WestCoast and TrueAmerican!

Current List for 3 days
MAP 4.6 2011/03/08 07:29:53 44.150 -129.470 10.3 OFF THE COAST OF OREGON
MAP 4.4 2011/03/08 07:19:33 44.335 -129.250 10.3 OFF THE COAST OF OREGON
MAP 5.0 2011/03/08 01:26:59 44.246 -129.391 17.8 OFF THE COAST OF OREGON
MAP 4.1 2011/03/07 15:59:27 44.446 -129.049 10.0 OFF THE COAST OF OREGON
MAP 3.9 2011/03/07 02:22:02 44.299 -129.136 10.8 OFF THE COAST OF OREGON
MAP 4.9 2011/03/06 22:23:15 44.334 -129.473 10.2 OFF THE COAST OF OREGON
MAP 4.8 2011/03/06 21:35:47 44.372 -129.346 10.9 OFF THE COAST OF OREGON
MAP 4.5 2011/03/06 13:46:37 40.404 -125.363 24.7 OFFSHORE NORTHERN CALIFORNIA

yep a 4.6.

I'm watching US.NLWA and TA.102D- but they're not showing up hardly at all on 102D...

And sorry my approx UTC times are off by a minute or two- but they are just estimates...The P-wave arrivals are tough to make out- those big ones you see westcoast are the S waves- the P waves are basically buried in the noise ahead of it- that's why it's difficult to know the exact origin time.

As a long time watcher of earthquakes & volcanoes and living in the middle of the Subduction Zone I watch this area with keen interest. There have been a lot of swarms in the area over the last few years with some quakes getting into the high 5.x range then it quiets down, but this time so soon after the Japan quake I am a little more nervous then usual.

I am not saying exactly where I am because I am staying stealth for posting in political forums but I can say I am located in one of the major cities talked about in these clips...

Here are some good links that might help illustrate what COULD happen if Cascadia goes...
Cascadia: The Hidden Fire - Trailer
www.youtube.com...

America's Tsunami: Are We Next?
dsc.discovery.com...

Mega Disasters: West Coast Tsunami
See what would happen to the west coast if the Cascadia subduction zone ruptures.
video.au.msn.com...

M4.4

March 20 @ 4:20:39 UTC

I wish it would just go already. I hate living here with the thought it will happen while i'm in the shower or least prepared. howabout RIGHT NOW. I'm ready.

dc-app3-14.gfz-potsdam.de...

If we know anything real about our core gyro and mantle flow it doesn't appear to be mainstream/public.

I ran CASMO with the WSM data but it would appear it's 2008 data Anyway to get more recent data? Or did they ditch these data collection methods?

I don't know but that subduction zone is looking pretty irritated. Looks like it could be close, but like they say, small earthquakes before don't necessarily mean mega earthquake. We'll see.

theworldlink.com...

news article on same. we've wondered about San Andreas, New Madrid and Yellowstone; guess we have another for the list.

"But sirens are not intended to warn everyone about distant events, and they have nothing to do with the large-scale local event (referred to as the Big One). When our local fault quakes and large tsunamis come ashore, we estimate only 15-30 minutes will pass before the tsunami reaches shore. The warning to evacuate to high ground is the three to five minutes of ground shaking during the earthquake.

In a distant earthquake event, overland evacuation routes will be unaffected except those impacted by the subsequent tsunami. Those in the inundation (flood) zone could evacuate before the tsunami arrived.

In local events, most roads will be damaged or blocked due to landslides and subduction (one geologic plate sliding beneath another); a vehicle will not be useful in a inundation zone. Following the shaking, people should
evacuate on foot to high ground (50 to 100 feet).

The probability of a subduction zone earthquake occurring in the next 50 years is 37 percent, according to research by Chris Goldfinger of Oregon State University and calculations the U.S. Geological Survey. That's greater than a one-in-three chance.

This very high probability demands that we take subduction zone earthquakes seriously and prepare. Odds are high that we will experience this event this generation, and even higher that the next generation (our grandchildren) will experience this event."

Originally posted by The Sword
Just another angle of DOOM for those who CRAVE doom.

Yes, you have no degree or formal study in earthquakes and yet, you think you're qualified to claim that one is going to hit soon?

Why does the study have to be formal? The dialectic is more effective quite honestly I think.

Originally posted by spirit_horse
The Cascadia Fault is a type of fault known as a MegaThrust fault. It is where the Juan de Fuca plate is going under the North American plate. The NA plate gets bound up and when it breaks loose it releases all that stored up energy which has been building for several hundred years and can cause a major earthquake 9.0 or better like the one in Indonesia in Dec. of 2004 that generated the Tsunamis that killed 250,000 or so people.

edit on 6/3/11 by spirit_horse because: spelling

It's also called a 'subduction zone'. Picture here earthquakescanada.nrcan.gc.ca...

The fact that all these subduction zones are acting up for the last few years, Chile, Japan, Indonesia only means one thing, an increase in activity in the Mantle which is leading to higher oceanic ridge activity and may affect volcanoes too.

4.4 just a hr ago today in the cascadia region off the coast of arkansas

Originally posted by Atrocities
4.4 just a hr ago today in the cascadia region off the coast of arkansas

Uh wrong state
Cascadia is Pacific Northwest
Arkansas is southern region and is also landlocked

reply to post by EvilBat
Oops, Oregon is what i meant. quakes.globalincidentmap.com...

reply to post by EvilBat


Well, whenever the New Madrid goes, it won't be landlicked anymore.

I read a idea that quakes also act like newtons cradle, and if you look at the map i linked it shows updated quakes and where/when/how deep, etc. It looks like the quakes that occur around the world act like the cradle just it depends on the direction of the shift of land where the force will go next but it will be on the otherend of the plate from what i am seeing. quakes.globalincidentmap.com... is another link tot he map i am looking at satelite is a good view too of the paltes and fissures.

I did an estimation of energy release based on the best info I could get of the 1700 Cascadia earthquake. Sediment records, rocks, the records in Japan where a tsunami hit. I estimate that the 1700 quake was a 9.1-9.2 magnitude. If something like that happens again it would be truly cataclysmic when the tsunami hit.