I knew that the Cascadia Subduction Zone was ripe for a big quake, but I had no idea that the whole fault has apparently been totally locked up for some time now. Scientists have studied the length of the fault and they can't detect any movement.

The stress can only be growing each day, and one day, all that pent up energy will be unleashed. Massive quake as well as a big tsunami. I read about it here.

It's stuff like this that makes living in EQ country interesting. You need to be prepared - always!

There is still so much we don't understand about earthquake zones in general, and Cascadia in particular. When I was an undergrad in the early 70's, the concept of Plate Tectonics was still relatively new, but geos had recognized that the west coast of OR, WA, and BC were a subduction zone. Even back then people were wondering why this subduction zone was seismically quiet. Only much later did research demonstrate that Cascadia did in fact have a record of major earthquakes.

In the past, the only available seismic array's were onshore. Since the portion of the subduction zone generating earthquakes is mostly offshore, these arrays could only detect quakes down to about M 3. We've known for decades that there was very little seismic activity down to that level. What is new is the ability to put sensitive Ocean Bottom Seismic (OBS) arrays right on the sea floor which can record for long periods of time and detect very small quakes. We now know that Cascadia is even quieter than we thought.

For a bit more general background, see Is 'eerie quiet' at Cascadia earthquake fault related to Nevada's swarm of tremors? (Note that the article says it probably isn't closely related to Nevada quakes.)

For more detailed into see the Cascadia Initiative website, and The Cascadia Initiative: A Sea Change In Seismological Studies of Subduction Zones (PDF).

I still chuckle, realizing I graduated in the late 50's with a minor in geology, and never once heard the phrase "plate tectonics." Back then geologists were into seduction, not subduction....

I also have to laugh. As of my mid-sixties geology courses in college, our professor was totally, and with utter contempt, dismissive of "plate tectonics" and "continental drift."

perhaps it is time for some fracking to release the pressure in increments.

Yup, a big one courtesy of the Cascadia is just a matter of when, not if. Interestingly, earthquake insurance seems slow to catch on here in the PNW. Same goes for retrofitting critical infrastructure -- but I suspect that will all change after a massive quake. And if any of the folks here have visited the OR coast, you've probably seen the tsunami evacuation signs in the low-lying communities.

A lot of faults are locked up right now. Quite a few of the major faults in LA are not moving very much, according to a recent news article. It is a concern to geologists.

There's no doubt that the whole West Coast is in for a pounding when these earthquake systems finally release all of that energy. Not sure that it will all happen at the same time. But if the Cascadia triggers, and later the San Andreas, the total damage on the West Coast will be astronomical.

Anyone who has got critical operations or industry needs to think about re-location.

Pete

I am not so sure about that, based on the SoCal experience. there are still numerous "soft story" apartments, the type responsible for significant loss of life in the 1994 Northridge quake that haven't been identified, let alone retrofitted. And that is right here in EQ Central.

Geezer in Chief.

Yes, I heard the same thing. True.
Also, quite a lot of historic buildings that have not been properly retrofitted, because the modifications would be too expensive or ruin the old architecture. LA is facing its share of real problems. and this does not include the fire hazard - which I think is actually the primary danger.

Pete

Just off the PNW coast a few... okay maybe more than a few miles, the ocean is heating up and it seems very localized, not GW, A 1,000 Mile Stretch Of The Pacific Ocea... Don’t Know Why


If the source of the extra heat is not solar activity which wouldn't cause such a local phenomena, maybe it's volcanic. If it's volcanic, maybe it's tied to the fault lock.

Dunno.

Actually the "blob" of warm water is due to the persistent ridge of high pressure that has lingered off the W coast. The high pressure ridge is in turn a result of warm water in the tropics. See Cliff Mass's Weatther Blog.

Interesting weather blog and the explanation makes sense. I kinda liked the unsubstantiated theory that the blob was linked to the fault lock. Now I read the whole thing is just a weather event. The cause and effect aspect of the article is very interesting, with the blob being a result of the weather pattern rather than the cause.

Another theory I've heard is that it is caused by HAARP and is intended to cause water utility companies to sell out so that ... never mind. I've never bought into HAARP being the cause of all things unexplained. I'm not sure HAARP is responsible for anything.

My theory is that the warm blob is at a portal where kaiju will come through.

There was a STUDY just published that looked at the emergency response in Oregon and the State of Washington. I think they identified about 40-50 towns and communities that are at immediate risk of a large tsunami, in the event of an earthquake (magnitude 8-9) on the Cascadia fault. The RESULT of the study is this - IF EVERYONE starts walking towards high ground immediately after the earthquake happens, then no-one should be killed by the tsunami. In other words, all these people are close enough to a large hill that they CAN make it ... provided that they get moving immediately.

I think the study said that there are about 95,000 people "at risk" from the tsunami wave - if it happens. Geologists seem to be very confident that the tsunami WILL happen.

The only real problem with the study, is that all these towns are going to get hit by a quake with magnitude 8-9. It will probably collapse a lot of buildings and generate a lot of chaos. So it's not obvious that everyone will start walking, immediately after that quake hits the area.

Pete

Pete -- a former Oregonian (Mt. Hood) whose favorite vacation destination was Cannon Beach, Oregon, the Cascadia Subduction Zone - a relatively recent discovery - fascinates me.

The Oregon coast was my family's frequent vacation spot in the 1970s-80s and I went to school (Oregon State) an hour away from Newport. Have spent countless hours/ days/ weeks strolling and laying on those beaches -- oblivious, as were most scientists, to any lurking geologic threat. If I had felt a tremor or even a significant quake motion while on the beach, it would not have occurred to me that a tsunami could be forthcoming. I had my last long vacation there in the early-2000s and still had no awareness of the threat -- while relishing my ocean-front suite on the ground floor.

Since the Indonesia tsunami disaster of 2004 and Japan's devastating tsunami in 2011, the parallels to the CSZ have received a great deal more attention in the Pacific Northwest, and elsewhere. If I were on that beach today I would be keenly mindful that any tremor requires an immediate response to head for the hills as fast as possible. I think many people -- at least residents of the Pacific Northwest -- are mindful of the threat these days. And they have tsunami signage now. Still, anyone would be frozen in place for seconds if not minutes while their brain processes what's happening.

And I worry that 15 minutes is not enough time to gain much elevation. Cannon Beach is a very big expanse of sand. Hopefully people could have closer to 30 minutes from the shaking to the tsunami. The feeble and unfit would be doomed without assistance. Reminds me of a woman who sloooowly waddled into Costco in front of me this week -- she'd need a Humvee to get from the beach to the hill in 15 minutes.

The worst scenario -- 9.0 quake that would last several minutes -- is impossible to fathom. Much of the coast could be cut off from inland -- there are so many vulnerable bridges and not many roads east. The relief efforts would have to eclipse anything we've seen in this country before.

Hope it never happens, but there is certainty now that it is only a question of when.


Cannon Bean on Google Map:

https://goo.gl/maps/HRTzn


Whenever my sister goes to the coast these days, I do my best mom imitation and remind her of the tsunami threat. Thanks to ETS, she has a small survival kit in her car that I put together for her a few years ago.

I just looked at that map again. We used to walk that beach for miles, day and night. Nowadays I'd be wearing at least a small backpack on that walk....

.

Pete, I think you are somewhat misunderstanding the implications of the study. It basically said that if everyone walked faster, then fewer people would die. It certainly does not say that "no-one should be killed by the tsunami."

See Don't drive, walk faster to survive Pacific coast tsunami

Note that in some towns in Oregon and Washington, there are large numbers of people living in areas where there is little or no safe high ground that could be walked to in the 20 minutes or so they would have to escape a tsunami from a Cascadia earthquake. There have been proposals to build berms or other structures to provide "vertical evacuation" locations in a few of these areas. However, this would be very expensive, and is still just a proposal. See 'Vertical' escape routes from a tsunami proposed on Long Beach peninsula .

We in California could generously assist by sending our waste materials north. They will achieve the necessary elevation in no time at all. And they will have methane from decomposing waste for emergency cooking!

There is a closed waste dump in our area about a mile from the beach that is vegetated and about fifty feet high. It would serve nicely for most tsunamis....

"There have been proposals to build berms or other structures to provide "vertical evacuation" locations in a few of these areas. However, this would be very expensive, and is still just a proposal"

I didn't know that. These people need to get moving. Even if they build some platforms on steel support structures, it would help a LOT!!!

Pete