A Serious Discussion On The Cascadia Subduction Zone and Latest Studies

wow,, very informative to the OP and the first reply. i had a great read .. thank you...


yeah maybe that 50 years is a bit off and a huge quake is going to happen sooner then we think... or they think..

lately iv been into tarot readings and general psychic\medium stuff.. tho i admit i need to get back to my old hobby of paying attention to this stuff ...

and its driving me batty and screwing up a good thing in my life ... so im back folks and finding the right thread to reply on is not easy..

sorry about being a bit off topic. now back on topic ..

all year so far iv felt that something major is about to happen to the world at large . im aware of the two 8 plus quakes on the other side yet i dont think that is it ..

so im still waiting to see whats going happen..
thank you both for the update and information.... brain food..

I noticed the ETS has been concentrated under the south/central Oregon area this past week, and thought I'd revive your thread, westcoast. We should keep it on page one.

Map Source(set parameters to 'color vs. time' and zoom in)


This area doesn't get a lot of action, compared to the northern and southern ends of the CSZ. The cluster seems to be migrating northwest over time; closer toward the locked zone. It bears watching, although odds are nothing significant comes of it.

The tremor and slip continues south and west of Eugene, Oregon.

Map Source(to duplicate-set parameters to 'Color Vs. Time', date Range 'May 5 - May14, and zoom in)

This thumbnail shows the whole subduction zone for the same time frame.


I noticed there was a small Mag 4.0 earthquake 89km off the coast of Ferndale, CA this morning. Here is the vertical component from PB.B046..EHZ., located in Petrolia, CA.



USGS looks to have this located on the Mendocino Fracture Zone, which is a common historical location, but I was surprised when looking at the different seismographs, that the motion seemed to have the highest amplitude in the vertical direction. I thought it would have been much larger in the E-W direction.

Rock on west coast.

Another 136 epicenters over 8.4 hours were added in the southern and central Oregon ETS region yesterday. That brings the total to 1084 epicenters and 68.5 hours over the past 10 days.


www.pnsn.org...

I wonder how long this tight cluster will continue?

Sure is quiet in here....
Well, this tremor episode is up to 118.9 hours and 1899 epicenters over the past 12 days. The action has expanded to Vancouver Island and back down to the central valley in northern California, while still continuing to pop under central Oregon.



I keep expecting a moderate earthquake offshore; something a little bigger than the Mag 2.5 north of Coos Bay this afternoon. Nothing.

On a different note, anyone know what would cause the polka dots on this spectrogram from the NE corner of the Olympic pennisula? It's from May 16th.
B001

Another day, another 28.5 hours/511 epicenters of tremor and slip.


Source

This episode seems to be picking up in intensity, and filling in the gaps, so to speak, along the southern half of the subduction zone. Here is a thumbnail of the last 13 days.



I kept checking the spectrograms yesterday, and had convinced myself that station L02D was experiencing technical difficulties or atmospheric interference of some kind. No, it was just sitting above the center of yesterday's activity.


And if you scroll down this page you can see that the tremor activity is energetically continuing.

ETA: John Vidale, is it possible that this is the beginning of this years "episode", beginning early again?

reply to post by Olivine


It's possible the episodic tremor and slip episode is starting early, but not likely. Generally, they've start near the northeast corner of the Olympic Peninsula, but there are exceptions. Occasionally, they come this early, and several intervals nearly this short have been recent.

We're not even sure that the 14-month pattern is stable in the long term. Some other regions have changed modes into different segmentation from time to time, although the longest set of observations in Japan look pretty stable.

We've stripped back to the permanent instrumentation in the region now, and are preparing another proposal to NSF to examine our existing data in greater depth and put out portable instruments on the Olympic Peninsula again.

Thanks for the reply John. I sure hope the National Science Foundation kicks down with all the $$$ you request. I really think the study of this slow slip phenomenon will prove invaluable when it comes to understanding large earthquake faults.

This current episode keeps ramping up: 40.8 hours and 713 epicenters yesterday.

Source

And for the past two weeks over 188 hours and 3123 epicenters.

(click to enlarge--map source same as above)

With the uptick in earthquakes worldwide over the past day, I hope the PNW stays quiet.
Looking at todays spectrograms, the ETS seems to be continuing...

reply to post by Olivine


Wow Olivine! Thanks for keeping things current. These last two weeks have been full of track meets (with my son), this past week was districts, plus a friend of his died tragically. Busy, sad week...so I obviously haven't been checking my 'normal' sites. Figures it would kick up.

Love the pics and links. I tend to agree with your theory that we might be looking at the next, early episode. Especially now that it appears to be some more action North, as John said we would typically see with the ETS. Although, it is still a different pattern, of course. But just when you think it's all figured out, mother nature will be sure to change it.

Like you, I most definitely expect to see a quake associated with the Southern Oregon tremor. I still just picture a long 2x4 being twisted and contorted at both ends and how the energy would transfer. We know we are due...the experts have been hammering that home this past year...somethings gonna give, it's just a matter of when.

If the ETS is indeed beginning again this early, I would see it as being a very bad sign. They do say in the program "Monster Quake, Are We Next" that the ETS could be a Catalyst.

reply to post by westcoast


Westcoast, I'm really saddened to hear about your family's tough week. That is a difficult loss for your son to experience.


So, yeah, I've been intrigued by this months activity. The monthly total for the entire CSZ is up to 242.8 hours and 3982 epicenters, but it has definitely been more active in the southern half of the zone. (this map only shows the southern portion--I wanted to zoom in to show more detail)


Source--from the ever vigilant folks at PNSN

Here are the thumbnails from May 20th and 21st--same source page.



Notice how far west (toward the locked portion of the fault) the tremor has moved in the past 2 days. I don't like it.

Since the activity has been so heavily skewed to the south, I guess this is just a mid-cycle 'burp'. As John pointed out, the main cyclic episodes usually start up near the Olympics.
But, if your 'see-saw' hypothesis holds true, be wary of a shake up in your neck of the woods.

The west coast is becoming active. A Mag 3.0 an hour ago, and now, it looks like something bigger. It isn't posted yet. Look at this static page here. I see something on GEE, too.

Very well could be from anywhere around the globe...still waiting on USGS.



Oh poop, Mag 6.1 Japan. Please hold on people of Japan & Fukushima reactors....

reply to post by Olivine
Olivine thank you for all your postings. I have been reading all the information you have been posting here and appreciate your informative posts. Compared to other areas on the ring of fire, the Pacific Northwest & California seemed to have been blessed with avoiding large earthquakes. Now regarding the volcanic activity, that is interesting to watch. I do wonder if Mt St Helen's is planning on getting active again.

reply to post by AuntB


Thanks AuntB.
I, too, am thankful the PNW has remained quite. I really hope Cascadia holds off a 100+ years; that should be enough time for seismic retrofitting and the population to be well educated on the impending quake/tsunami/loss of infrastucture.

I haven't updated because it looked like the ETS was slowing to a stop. Not the case. It just hopped up to Vancouver Island, and then back down to the southern end. Another 30.2 hours and 523 epicenters over the past 2 days.

Tremor Map source

I believe the subduction zone will not do anything in my lifetime or your childrens lifetime. I am sure tho that this gloom and doom is the norm on planet a.t.s. members. I gave you my opinion, just what you wanted to hear.

reply to post by Olivine


Hmmm...and a nice moderate quake to go with it:

2012 May 25 07:26:24 UTC
Versión en Español
DetailsSummaryMapsScientific & TechnicalAdditional InfoEarthquake Details
This event has been reviewed by a seismologist.
Magnitude 4.1
Date-Time Friday, May 25, 2012 at 07:26:24 UTC
Friday, May 25, 2012 at 12:26:24 AM at epicenter
Time of Earthquake in other Time Zones

Location 50.395°N, 129.829°W
Depth 10.1 km (6.3 miles)
Region VANCOUVER ISLAND, CANADA REGION
Distances 174 km (108 miles) W of Port Hardy, British Columbia, Canada
227 km (141 miles) SSW of Bella Bella, British Columbia, Canada
498 km (309 miles) WNW of Vancouver, British Columbia, Canada
518 km (321 miles) WNW of VICTORIA, British Columbia, Canada

Location Uncertainty horizontal +/- 25.4 km (15.8 miles); depth +/- 4.9 km (3.0 miles)
Parameters NST=138, Nph=140, Dmin=232.7 km, Rmss=1.06 sec, Gp=180°,
M-type=body wave magnitude (Mb), Version=B
Source Magnitude: USGS NEIC (WDCS-D)
Location: USGS NEIC (WDCS-D)

Event ID usb0009ytx

source

I haven't posted any tremor updates in a while because the activity quieted down; just small pockets of ETS bouncing between the northern and southern ends of the CSZ.
Yesterday, was different--evenly spaced along the entire length of the fault...


Source

Yet another doom and gloom thread,funny things probably have been the same for thousands of years,yet some person gets an epithany and west coast will fall into the ocean,bunch of crap IMO,get a freakin life

I appreciate this thread very much, please keep the information coming.

reply to post by Olivine


We're thinking that widespread apparent tremor across Cascadia might be a problem of our software being confused by bad telemetry or some such artifact, although we are not yet sure.