If you would like more information about what's happening in Oregon, please FReepmail me.
Posted on 07/24/2018 7:57:45 PM PDT by Robert A Cook PE
USGS reported 11 earthqaukes (the largest a magnitude 5.6) off the Oregon coastline today, right at the Oregon-CA border on the Juan de Fuca rise associated with the subduction zone of the Pacific plates and North American plates. This area, the Juan de Fuca fault subduction zone, has been quiet since 1700 - when a magnitude 9.0 quake occurred dropping land as much as 2 meters (9 feet) over the entire 800 mile Vancouver-Washington-Oregon coastline. That quake in 1700 caused documented 10 meter (30 foot) high tsunami's recorded in Japan that crushed many villages and towns.
Many previous large earthquakes have been discovered using underwater records of huge landslides/mudslides at 300 - 350 year intervals up and down all of the river outlets on the Washington-Oregon coast. Indian verbal legends also report the 1700 earthquake, but no earlier oral records are known.
At today's 318 year interval (2018-1700), it's a little bit early to claim today's earthquake swarm is a pre-cursor to the very large subduction quake, but small pre-cursors are expected before such a large quake. On the other hand, sufficient movement of the Oregon-Washington submarine floor might reduce the magnitude of a single very large quake.
The last such subduction zone faults in a comparable underwater subduction zone include: the Good Friday Alaska quake in 1964 (mag 9.2), the Mexico City earthquake in 1985 (mag 8.1, 9500 dead, 100,000 homeless), the Chilean earthquake in 1960 (mag 9.5, 2500 dead, 2 million homeless) the Chilean earthquake in 2010 (mag 8.8), the Sumatra-Indonesian quake 24 December 2004 (230,000 dead and missing), the New Zealand quake 22 Feb 2011, and the recent Japanese earthquake in 11 March 2011 (mag 8, millions displaced, 10's of billions in damage).
Large Pacific Rim earthquakes are troubling: in the southeast corner on 27 February 2010, the southwest corner 22 February 2011, the northwest corner on 11 March 2011.
And today? Only the northwest corner (Alaska-British Columbia-Washington-Oregon) has not moved for hundreds of years.
Know any geologists? Talk to them.
The one I talk to says that the coastal range is humped up several feet in places.
When that thing goes, it aint gonna be pretty.
I have been monitoring the Cascadia Fault for the last 5 years and this has a new pattern.
Multiple quakes near the key point.
Watch for others along the fault in the coming months.
Could be nothing....could be something.
Hard to say.
Three years ago there was a large amount of activity directly east of this quake near the Nev-CA-OR border.
It almost looked like a new volcano was growing in the Cascades.
Now nothing for almost 2 years.
Again, look for a pattern of new quakes along the Cascadia.
Cascadia would likely take out most the bridges in the Western 1/3 of the state.
Yes it can and does. What usually happens is there are several smaller ones before a big one.
This subduction zone runs over a very long distance.
These are far worse than side slips like in the LA area. These are subduction where the stress is relieved by the plate that is forced down by the one trying to slide under, pops back up. It results is a massive displacement of water.
Just go take a look at the Japan earthquake videos.
BTW, they took videos of the building in Tokyo which showed that the buildings not only swayed, they quivered. Another few more minutes and those would have suffered much more damage than they suffered.
If you would like more information about what's happening in Oregon, please FReepmail me.
Around springtime is a higher risk of earthquakes due to water pressure on rocks, higher water table, slight movement in soil and rocks due to water displacing things. So I read somewhere.
... Believe it of not .... the Motto here is San Dimas is ..... "San Dimas .... an Excellent Adventure!" ..... And unfortunately for you ..... and possibly good for me .... there is a final sequel in the works ....... Stay Tuned!
That would be true for a strike-slip fault. For a subduction zone, which this is, it may be releasing pressure at the foci (the 11 points they mention) but increasing tension somewhere else as 2 plates collide. They don’t have a method to foresee how everything will crash together.
Or stress transferred...
A winter/spring event would save a lot of lives here on the Coast. I think this may be a record summer for tourists here on the Coast. I don’t think they may fair better in Portland or Seattle though due to aged buildings and infrastructure.
As an aside, at least one coastal town I know of has stockpiled body bags. Others may be doing the same but not mentioning it.
I remember after the loud crack and jolt looking up at the water towers on the foothills of the San Gabriel mountains. and thinking. Hope that’s it!
Im in Boundary County Idaho on the Canadian border...plenty of Bald Eagles here too.
I’m lost. Who will be left to fill the body bags and what keeps them from being destroyed along with the new occupants? I must of missed something here.
plenty of fish and little critters to eat in Alaska as well, but they are looking for someone who chopped down three trees in Alaska that had active American Bald Eagle nests. That’s a shame because only 50% of eaglets make it to adulthood.
Adult eagles mate for life. they are more loyal than people.
Speaking of which, enjoy this funny American Bald Eagle video.
This is a juvie eagle who is unable to hunt yet, which I’m sure this baby squirrel can be thankful.
in a few years that would be a snack.
Off topic... we are looking at San Dimas, Glendora and La Verne area to settle in our senior years. Children live out that way.
Any bad areas to avoid? LOL
I could only wish. The Netflix movie How It Ends contains clues to the left coast’s demise.
The survivors. Same people who did it in Japan, Thailand, Indonesia
.... I remember .... We were woken by a Giant bone jarring jolt accompanied by intermittent flashes of very bright light Filling the house..... to us it seemed like the "End of the World: ..... And as a reflex I turned on our newly acquired Big Screen ... and what we saw was the images of glowing Lava bubbling out of crevices and flowing down streets ......
.... At that moment we KNEW it was the time of the Apocalypse!!!! We didn't quite know what to do.
.... Then I turned to a different channel.
...... And that is what living in Southern California is like ....
.... BTW .... The Lava? ..... A local station was airing ..... "Journey to the Center of the Earth." .... Which I now Hate ....
I recall the words of one geologist who said that basically, everything west of I-5 would be toast.
I was here for the 2001 Nisqually quake, and that was only a 6.8. That was my first, and so far only earthquake.
There’s a good chance that what they call the “full 9 rip” will happen in my lifetime. Where I am currently located, I may be a little further away from the Cascadia then the epicenter of the Tohoku quake was from the coast of Japan.
Nonetheless, I am pretty much guaranteed to feel it. I can only imagine with horror what life will be like afterwards. It’s likely that we’re going to lose electricity for at least a month, drinking water and sewer for anywhere from three to six months, and it just gets worse after that.
No! I’m nervous enough... I will now read the article, thanks for the ping. I wonder if anyone on the coast felt it.
I hope you are doing very well!!!
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