Earthquake!

[Brewdude]

Just was laying in bed semi-awake at 5AM and the house started moving and shaking, windows rattling! This lasted less than 5 seconds and felt like about a 4.5 earthquake. So now wide awake and unable to go back to sleep. These "little" quakes are not known for aftershocks, nor are they considered a precursor to a larger one. Still, it got my attention!

Last 4-pointer we had was about 2 yrs ago and that one was local to my area as I suspect this one was. Back in '01 we had a large quake that affected the whole Puget Sound region. 6.8/7.2 depending on which report you read, and it absolutely scared the crap outta me. I was at the brewery and the whole building started rocking back and forth about 12" for what seemed like half a minute.

Being as it was a deep quake it didn't do as much damage as a shallower one would. And they say we're due/overdue for a catastrophic 9-pointer which will create tsunamis that will devastate the coastal area and flatten Seattle! I hope to be long gone by then!

:no:


No Cheers!


RR

 

[Lonecoyote]

Rande, glad it was not the BIG one!! However any earthquake can be a bit frightening, you don't know what's coming next. I wish you well and be safe. 


KEEP ON PUFFING!!!

 

[Stick]

Crikey Rande, you've had it all over the past few weeks. What next?!

(Glad to hear you're ok (again))!

 

[Ozark Wizard]

The Juan De Fuca plate is being subducted towards the PNW, being push by the Pacific Plate moving east, and the North American plate being pushed west. The Juan De Fuca plate is kind of sticky, and as it's being slid under the West Coast, it hangs up in places, wrinkling the landscapes in Oregon and Washington States. When it finally lets go, it slips quickly until it hangs up again. I forget how long it is between major slippage, but an associate of mine at the USGS out there told me of old growth trees found with stuff imbedded in them from a Tsunami generated by a slippage on the Cascadia Fault, and stories told by the native American tribes in the area described long shaking of the ground, followed by the ocean receding and then flooding the land, back in the 1700s. "Experts" suggest that major events like this occur on an average of 500 years or so, so you may have time to make a leisurely retreat before it happens. Maybe not even in our lifetime. It seems that there have been quite a few shakes in recent years going on in the PNW, but it is my thought that many small slips do less damage than one big one, relieving the plate pressure a little at a time..

When shopping for your new digs, think east with elevation. :lol!:

 

[Stick]

Aint plate tectonics fascinating?! Like huge beer mats moving about on a huge bowl of simmering porridge. Fascinating.

 

[KevinM]

Aint plate tectonics fascinating?!  Like huge beer mats moving about on a huge bowl of simmering porridge.  Fascinating.

LOL! Yes, exactly like that!

 

[Ozark Wizard]

I have a passing interest in grand scheme flux and growth, (i.e. astrophysics, stellar creation activity, planetary behavior, and on a smaller scale, this little blue marble wobbling around it's sun.) In large timelines, well, larger than a few millennia, things are happening pretty fast here. To think we are wandering about on little bits of cooled matter that is floating about on a blob of liquid is rather humbling. The pot of porridge is a great analogy, just short of a rolling boil. In Iceland you can see how quickly the Atlantic is spreading, and in doing so is pushing on everything either side of that fissure. Japan is getting squashed. When the Philippine and Eurasian Plates push down and overrun the Pacific Plate, they have quick subduction occurrences that are relatively mild, but occasionally the Eurasian plate gets bunched up. When it releases, the land drops, think it dropped a meter or so last time, it creates those big waves in the ocean. (The energy released had to go somewhere) Bammo, Tsunami!

There is a similar set up off the PNW. There are multiple USGS sensors placed around the PNW, most from the St. Helens episode, and they record the rising and falling of the land. It might be possible to go to their web site and see the data, it used to be public intel. After the 2001 quake in Washington, many of the sensors dropped in elevation, as the pressure was released and the American Plate settled down.

When one thinks about the crust of the Earth, it reminds one of the crust on a loaf of bread. Rather thin, and fragile.

There was a scenario I saw somewhere some time ago, probably after what happened at Fukeshima(sp?), what may happen if that tsunami hit Seattle and Portland. I lived in the West Hills of Portland at the time, and the scenario had me keeping one of my sailboats always prepped and loose from the trailer. Most of the SeaTac area was under water, and Portland is only a little over a couple of hundred feet above sea level, even though it is quite a bit further inland. ( Tide tables apply all the way to Oregon City, so a tsunami would fly right up the Columbia and Willamette.) That's a lot of folks swimming.......

 

[Stick]

Sounds very much like you and I are peas out of the same pod, Wiz, when it comes to our interest in our little marble and all it sails in.

I can remember reading about the mid Atlantic ridge, its divergent plate boundary, and how it was discovered by chance that this was the process that formed new earth's crust. The magnetometer also revealed that the earth's polarity had switched with worrying regularity. Imagine if that happened now! Apart from the affect on tech, it gets me wondering about, amongst other things, the affect it would have on migratory species. Mmm, think I might ponder that over a bowl of SJF.

 

[Ozark Wizard]

 The magnetometer also revealed that the earth's polarity had switched with worrying regularity.  Imagine if that happened now! Apart from the affect on tech, it gets me wondering about, amongst other things, the affect it would have on migratory species.  Mmm, think I might ponder that over a bowl of SJF.

I think it was in an article I read in the Smithsonian magazine regarding magnetic shifting, (or was it Scientific America? I forget..) and it was already affecting migratory species. As the core shifts mass, and the iron density changes, the magnetic field moves with it. NASA claimed that the magnetic pole is moving at a rate of 10km per year, and the rate of movement has escalated to 40km/yr as of 2003. Santa is going to move to Siberia soon!

I saw that GPS satellites had to be recalibrated after the earthquake in Japan, due to that fact the earth actually pitched a tad and slowed rotation, which put the current coordinates off by enough to have you want to turn your vehicle almost 100 meters off course. Nasty business for our new unpiloted cars, and those who would rather stare at their screens than trust their eyesight.

Alas, I think I will join you in that pipe of SJF.

 

[Ozark Wizard]

https://www.nasa.gov/vision/earth/lookingatearth/29dec_magneticfield.html

This is a great read.... It also shows how magma displacement effects magnetic fields.

How Fragile we are............

SJF sounds good, I'll join you.......

 

[Stick]

Great article Wiz, thank you. That diagram of the magnetic field during a reversal looks really mixed up.

Think I'll sit a while with you on the decking...

 

[Timbo]

Nasty stuff Brewdude, hope your nerves have settled down mate. Maybe a nice pipe to help you relax.

Oz and Stick, I find cosmic and planetary engineering to be fascinating too so thanks for the information and interesting links. Good reading.

Cheers

Tim

 

[Brewdude]

According to the local news just now, the quake was a 3.2. And while that's 10-fold smaller what I thought it was it still felt like a 4-pointer to me. I've experienced 4-5 "mild" quakes since I've lived in the Pac NW, and apart from the bigger one in '01 this felt like at least a 4-pointer to me.

And that might've been due to my specific area, or the way it struck in my bedroom which is on the upper floor. Upper areas can shake more than lower ones due to the inertia.

Still it got my attention!

:silent:


No Cheers,

RR

 

[Natch]

Good to see the interest in one of my favorite topics. Depending upon the courses I'm teaching each semester, I often include anywhere from a week to a quarter of the semester on plate tectonics. Mind boggling to many of my students, but fascinating once they wrap their head around it.

A geophysicist friend of mine put it into a perspective that my students seemed to grasp, he would say that if Columbus was leaving the Old World today he'd have to travel 78 feet further to reach the New World.

Natch

 

[Bub]

Now I am afraid.
I live in Missouri.
What should I do?
Stock up on booze or pipes?

 

[Ozark Wizard]

Hey Bub,

You might be referring to the New Madrid Fault Line. Yup, we both are pretty close to the zone of seismic influence. Though you are a bit closer to the river. My plan is to get ready for the raised taxes for having beach front property. I don't know about where you're at. I'm glad I'm sitting on one of the oldest mountain ranges on the planet, so things are pretty established. I have faith in the Ozark Plateau holding up.

The Navy paints a grim picture for the PNW and Florida, but it would be cool the sail the Ozark Sea....

Wow. Tried to share another pic from them and got a 403 "Forbidden" screen.. Hmm.. Let's try this...

Oh now they are just being difficult.....

How about this?



Well, at any rate, the fishing is about to get a whole lot better here, though I'll have to use a bathyscaph to see Graceland....