Author Topic: Earthquakes  (Read 832 times)

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Offline CarbShark

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Re: Earthquakes
« Reply #30 on: July 06, 2019, 07:04:37 PM »
Would that make yesterday's quake a beforeshock, where rumbles now are aftershocks?

The 6.5 is now a foreshock. And there were smaller foreshocks before that one.

And there are lot's of aftershocks now, but they are all aftershocks of the 7.1.

And there is fear that the 7.1 itself could be a foreshock for an even bigger break on the San Andreas fault, which could be "the big one"

"Looks like another perfect day"

(Did you see footage of the Dodger game where they through three pitches during the shaking?)
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Offline brilligtove

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Re: Earthquakes
« Reply #31 on: July 06, 2019, 08:09:57 PM »
Foreshock sounds so much better that beforeshock. Neat.
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Offline stands2reason

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Re: Earthquakes
« Reply #32 on: July 06, 2019, 10:44:17 PM »
Never lived anywhere seismically active. All I know about earthquakes is what I saw on Mythbusters. If you haven't that episode, it's great. They show how an earthquake disintegrates masonry (block/brick). Because, you know, it shakes the mortor loose. You do not want to be inside of that kind of building during or after an earthquake.

There was an iconic collapse of a 6 or 8 story brick apartment building (IIRC) In the SF quake of 1906. Now that was lack of foresight, or desperation.

Offline CarbShark

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Earthquakes
« Reply #33 on: July 07, 2019, 02:16:24 AM »
Never lived anywhere seismically active. All I know about earthquakes is what I saw on Mythbusters. If you haven't that episode, it's great. They show how an earthquake disintegrates masonry (block/brick). Because, you know, it shakes the mortor loose. You do not want to be inside of that kind of building during or after an earthquake.

There was an iconic collapse of a 6 or 8 story brick apartment building (IIRC) In the SF quake of 1906. Now that was lack of foresight, or desperation.
Unreinforced masonry is a death trap.

Properly reinforced masonry is much better.

But properly sheathed wood frame, bolted to the foundation is best. 


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and Donald Trump is President of the United States.

I'm not a doctor, I'm just someone who has done a ton of research into diet and nutrition.

Offline Awatsjr

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Re: Earthquakes
« Reply #34 on: July 07, 2019, 11:45:58 PM »
The way I see it, at least earthquakes leave you in the same county.

Offline CarbShark

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Re: Earthquakes
« Reply #35 on: July 08, 2019, 12:01:50 AM »
There is one thing about earthquakes that is kind of cool (as long as they aren't too dangerous)

And that is for the next week or so everyone you see in your neighborhood, at work, in the stores on the street, are all in the same boat. You all have survived a dangerous and frightening  shared experience

Everyone within thousands of square miles felt the shaking some more than others, some less. And everyonel had similar but still unique experiences reactions. (and they're happy to talk about them)

Suddenly rich, poor, man, woman, girl, boy, black, white, asian, native, LGBTQ or any combination, we all got shaken up and down.

I feel more a part of my community after an earthquake than any other time. (That includes other disasters I've experienced: tornadoes; hurricanes; wildfires and floods).

I hate to say it but I rather enjoy a good earthquake every now and then.
and Donald Trump is President of the United States.

I'm not a doctor, I'm just someone who has done a ton of research into diet and nutrition.

Offline lonely moa

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Re: Earthquakes
« Reply #36 on: July 11, 2019, 05:16:05 AM »

Unreinforced masonry is a death trap.

Properly reinforced masonry is much better.

But properly sheathed wood frame, bolted to the foundation is best. 


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Wood frame on piles, our old farm cottage just rock and rolls in the shaky islands ... so far.  We seem to be getting a heads up on the overdue Alpine Fault of late.
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Offline Ah.hell

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Re: Earthquakes
« Reply #37 on: July 11, 2019, 09:29:12 AM »
I didn't feel it. I was on the ocean, and 2,500 miles away ;D

I was in Tecate, BC, Mexico when I felt an earthquake. My first impression was that a worker with a small motorized cart had bumped my cabin. But the shaking continued. I said to myself, "I think this is an earthquake. You're supposed to go outside when there's an earthquake." So I went out onto my patio. The shaking didn't last long. The epicenter was about 90 miles east, IIRC. No damage. Some aftershocks were reported but I didn't feel them.

You are not supposed to go outside during an earthquake. Anything on the roof our outside walls of your building could fall as your going through the door. It's safer to stay inside until the shaking stops, wait a few seconds, then go outside.

If you're outside that's the safest place usually, as long as you're not near any collapsing structures.
If you've ever seen the architecture in Mexico, you should definitely go outside in an earthquake.  Lots of unreinforced and lightly reinforced masonry.  I stayed at place on the coast, my first thought was, "Jesus, I hope there isn't an earthquake while I'm here."  My American ex-patriot host said they didn't have them.  A.  Pacific Coast of the Americas, there are earthquakes.   B.  There were piles of old brick everywhere, there were Earthquakes.  C.  Seconds on google showed there had been a major earthquake that leveled the place just before they moved there. 

Wood Framing is great for earthquakes as noted.  It just moves along with quake but stays standing. 
Steel framing is also great depending on the details.
Properly design Reinforced Concrete Masonry is basically indestructible, same with properly designed reinforce concrete.

Unreinforced masonry is the absolute worst.  Loads on the structure are proportional to the mass on account of F=MA.  Masonry is very massive and without rebar it has basically zero lateral strength.

My wife felt it 170 miles away in Paso. I was moving around and didn’t.
Paseo? Paso Robles?
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Paso Robles?  I lived there at the time of the San Simeon earthquake.  A few classes were cancelled because the profs were off doing the post earthquake assessment of the buildings.   
« Last Edit: July 11, 2019, 09:38:17 AM by Ah.hell »

Offline Awatsjr

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Re: Earthquakes
« Reply #38 on: July 11, 2019, 10:44:29 AM »
Yes, Paso Robles. We used to live in a small town outside of Auburn, CA and felt more small quakes there than here from the Truckee area fault.
 Weird. Of course now we are 25 miles from the San Andreas fault ....  :)

 

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