Seismic Scare At The Zooby Brush Shelter

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Earlier today I was briefly scared out of my wits when a seismic wave passed beneath the Zooby brush shelter here in San Diego, and seemed to toss the whole place up unto the air a couple feet as it passed underneath.

Apparently the epicenter was about 50 miles away, out in the ocean to the southwest: (marked by a star)

Event 14065544 Map
Address:http://pasadena.wr.usgs.gov/shake/STORE/X14065544/ciim_display.html [Broken] Changed:6:34 PM on Tuesday, June 15, 2004

5.7 richter, it was just the one big impulse, followed by decreasing trembling. Whenever this happens, I'm always on tenderhooks for a little while wondering if there is more coming.

The interesting thing with this one is that I was aware of a definite direction to it. It hit from behind me, went underneath, and continued on in the direction I happened to be facing.
-----------

Post your interesting earthquake stories and data.

-Zooby
 
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Ivan Seeking

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Tsu and I were on the fifth floor of an apartment building in Glendale, Ca., when we were hit by a quake of similar magnitude. It hit very early in the morning, I think about 5 AM, so we both bolted from bed into the hallway. Now we have both been in some serious quakes but on the fifth floor this was like no other earthquake I have experienced. With the degree of motion that could be felt I thought the building was coming down.

When the quake was over I found myself behind Tsu and hovering over her, and reaching around her and holding on to a couple of convenient hand grips; kindly provided by Tsu. :rolleyes: She looked at me and said: "Now I know what you're really worried about saving"
 
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Ivan Seeking

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zoobyshoe said:
The interesting thing with this one is that I was aware of a definite direction to it. It hit from behind me, went underneath, and continued on in the direction I happened to be facing.
Was there any damage? Did you hear anything before it hit?
 
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I haven't heard of one report of damage. It was a very much up and down event, and so brief there was no collateral shaking.

A very loud bang, almost sonic boom strength, accompanied the movement of the house. There wasn't any preceeding noise I can recall. The bang seemed to be produced exclusively by the sudden strain on the structure of the house itself: it seemed to sound all around me rather than from below.

My guess is that it was the result of one of those events where one plate is slipping beneath another, rather that the kind where the plates slide laterally.
 

Evo

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My best friend lives in Sicily where there are frequent earthquakes. He seems to have the ability to sense earthquakes just minutes before they are felt. Since he was a small child he would feel a weird sensation that would even wake him from sleep just moments before an earthquake would hit. It was a very specific sick feeling. It was several years before he associated the feelings with the earthquakes. The last earthquake, he was awakened from a deep sleep and was able to make it to his mother's room before the quake hit.

But he can also sense minute differences in temperature and humidity. He's an oddity.

Zooby, do you get any sensations before an earthquake?

P.S. Glad you are ok. :smile:
 

Math Is Hard

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The earthquake wasn't too bad today, but I am in a big office building. I was up at UCLA, so it shook us a few minutes before it hit the Zooby shack.
It did bring up reminders of the Northridge quake 10 years ago. That was quite an experience. Had to get the cat surgically removed from my face afterwards.
Earthquakes are weird because they make me sea sick. I have a funny inner ear, I guess.
 
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I don't get any special sensations whatever before an earthquake.

The first big one I was in after I moved to SoCal was at night and woke me up. The room seemed to be spinning like it used to when I would get plastered. I became very anxious because I was sure I must be drunk, but too drunk to recall why I would have gotten drunk out of the blue after 15 years of not touching the stuff.

Eventually I woke up enough to figure out that was my first earthquake. Between the shaking and not being able to explain why I was drunk, I ended up having to go to the bathroom.

So that incident had aftereffects, but nothing unusual has ever preceeded a quake. I'm always completely surprised.
 

Ivan Seeking

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Math Is Hard said:
It did bring up reminders of the Northridge quake 10 years ago. That was quite an experience.
Oh boy I bet that was fun. For some time we lived near Cal State Northridge; near Van Nuys [Parthenia] and Sepulveda. I understand this area was hit really hard. Where were you located at the time. Do tell. :tongue2:
We were really glad to be gone already.

Had to get the cat surgically removed from my face afterwards.
:rofl:
 

Evo

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Math Is Hard said:
The earthquake wasn't too bad today, but I am in a big office building. I was up at UCLA, so it shook us a few minutes before it hit the Zooby shack.
It did bring up reminders of the Northridge quake 10 years ago. That was quite an experience. Had to get the cat surgically removed from my face afterwards.
Earthquakes are weird because they make me sea sick. I have a funny inner ear, I guess.
See, you do feel effects from the earthquakes, and apparently so does zooby, just not before. Zooby, don't earthquakes produce ultrasound?

You and zooby need to move here with me, where you spend most of the year safely in the basement waiting for tornadoes to hit. :biggrin:
 

Ivan Seeking

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Evo said:
My best friend lives in Sicily where there are frequent earthquakes. He seems to have the ability to sense earthquakes just minutes before they are felt.
Human beings can detect sounds in the frequency range 20-10,000 Hertz. If a P wave refracts out of the rock surface into the air, and it has a frequency in the audible range, it will be heard as a rumble. Most earthquake waves have a frequency of less than 20 Hz, so the waves themselves are usually not heard. Most of the rumbling noise heard during an earthquake is the building and its contents moving.
http://earthquake.usgs.gov/4kids/facts.html [Broken]

1. P-Wave: These are called 'P' for Primary Wave. They are the ones that travel fastest and thereby are usually "felt" first. They are basically sound waves that travel thru the earth from the epicenter of an earthquake. Physics types know this as a longitudinal wave. It "shakes" things in the same direction it travels. For example, if a P-Wave is traveling West to East, all the things in the way, like people and buildings, will oscillate or move back and forth in the West-East direction. Similar to a long straight line of bumber cars! The one in the rear hits the first one and it hits the one in front of it and so on and so on. After each collision, the car bounces back to its original position only to be hit and bumped forward again. Some properties?
a.FAST! They can travel up to 20 times the speed of sound in air!
b.Usually noticed like, "I heard the earthquake coming!" This is because it IS, indeed, a sound wave. Most often it isn't noticed tho.
c.Very little, if any, damage.

2.S-Wave: These Secondary Waves are much slower and much more destructive than P-Waves. They are transverse waves. This means they make the earth vibrate perpendicularly to the direction of the wave travel. Not getting it? Think of a rope loosely held by two people. One person starts moving his/her/its hand up and down rapidly. Notice the "wave" in the rope goes from person 'A' to person 'B' while the rope itself simply vibrates up and down - perpendicular to the direction between the two people. This wave causes damage due to its configuration. It causes buildings to be thrust upward from the ground then the ground drops out from under it as the wave travels by.

3.Rayleigh Wave: This is a combination P and S-Wave. It's analogous to an ocean wave. It's both longitudinal AND transverse. It's hard to envision, but look at the diagram below. The surface, while being told to vibrate forward and backward in the direction of the wave is also told to vibrate up and down perpendicular to the direction of the wave. Got it? The result is the surface moving in a vertical circular path - back and forth AND up and down. The Rayleigh wave is particularly damaging because it tells structures to move in two directions at once.

4.Love Wave: Not a scary sounding wave, right? Damaging, yes! This one is sorta a Rayleigh Wave on its side. It tells the surface to move forward and backward AND left and right at the same time, sorta like a surface circle. Also, very damaging.
http://www.darylscience.com/Demos/PSWaves.html
 
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I lived in Tornado country for years in Ohio and also in Minnesota, so I know what that's all about. When I was in college in Ohio there was massive thunderstorm that spawned 77 twisters in that state alone. There was a little town called Xenia, I think, that was just about wiped clean away.

I almost got pulled into the sky, myself that day by means of umbrella and wind gust. All these people were standing at the door of a dorm yelling at me to get back inside.
 

Math Is Hard

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Zooby, pack up! We're going to live with Evo at the haunted mansion! :rofl:

I'm near Culver City, Ivan, just south of Santa Monica, and I was in the same area at the time (of the Northridge quake). The 10 freeway collapsed just about 5 miles or so from where I live. You might remember the famous story about the CHP office who went flying off it when the quake happened...?
 

Evo

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Math Is Hard said:
Zooby, pack up! We're going to live with Evo at the haunted mansion! :rofl:
Alrighty then!!! Hauntings, tornadoes, and I've even heard of earthquakes nearby! Not to mention the flying cats!!!! A fun time for all!!!! :biggrin:

Math Is Hard said:
I'm near Culver City, Ivan, just south of Santa Monica, and I was in the same area at the time (of the Northridge quake). The 10 freeway collapsed just about 5 miles or so from where I live. You might remember the famous story about the CHP office who went flying off it when the quake happened...?
YIKES!!! Math Is Hard, I'm worried about you now. :frown:
 
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Math Is Hard said:
Zooby, pack up! We're going to live with Evo at the haunted mansion! :rofl:
Oh, I forgot about Evo's poltergeists. I'll stick with the quakes.
 

Ivan Seeking

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Evo said:
YIKES!!! Math Is Hard, I'm worried about you now. :frown:
Don't worry Evo. Math Is Hard isn't a CHP officer.
 

Math Is Hard

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Aw, c'mon Zoob. We'll make it a reality show. We've got beautiful Evo, mistress of the dark, and a host of wacky characters.. my film crew is ready to go!!
 
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Math Is Hard said:
Aw, c'mon Zoob. We'll make it a reality show. We've got beautiful Evo, mistress of the dark, and a host of wacky characters.. my film crew is ready to go!!
No, I'm not fond of sideways flying cats.
 

Evo

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zoobyshoe said:
No, I'm not fond of sideways flying cats.
Oh yeah right! My cat flies sideways ONE time and you won't come here. :grumpy:
 
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Evo said:
Oh yeah right! My cat flies sideways ONE time and you won't come here.
There's also the fact that you live right next to Montgomery Burns' Nuclear Power Plant.
 
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I felt the quake yesterday down here in southern OC, but it was just a blip. barely noticed it. but I'm not sure which one it was. According to the USGS.gov site there were 2 quakes yesterday- a 5.1 off the baja coast, and a 3.9 centered just south of agoura hills, ca at about the same time. Either way, I barely felt it here.
 
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Zantra said:
According to the USGS.gov site there were 2 quakes yesterday- a 5.1 off the baja coast, and a 3.9 centered just south of agoura hills, ca at about the same time.
I wondered if there hadn't actually been two separate quakes since Math Is Hard described the epicenter as being near her.

Being only about 50 miles from the epicenter of the one that was off the coast of Tijuana, I'm pretty sure that is the one I felt: event # 14065544, as the US Geological survey has listed it.


Event 14065544 Map
Address:http://pasadena.wr.usgs.gov/shake/STORE/X14065544/ciim_display.html [Broken] Changed:1:35 PM on Wednesday, June 16, 2004

When I first went to the site yesterday they said it was a 5.7. Today they've downdraded it to 5.2.

On the statistics pages of that site they list the locations and rough intensity estimates of reports they've recieved. Most of the reports, and those with the highest intensities, are from San Diego. I guess we felt it here more than anywhere else.
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The earthquake facts posted by Ivan are interesting and informative. I think I was hit by the Rayleigh type wave, described in his link.
 
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Math Is Hard

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well..It wasn't that near me, though. If you were to measure the distance from San Diego to the epicenter, LA would be about two-thirds of the way there.
 
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Math Is Hard said:
well..It wasn't that near me, though. If you were to measure the distance from San Diego to the epicenter, LA would be about two-thirds of the way there.
This is true. I think if you lean out the window and throw a stone, you'll be able to hit Zantra's agoura hills, ca., from where you are, though. That one was alot smaller but you are alot closer to it.
 
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Agoura hills is around the simi valley area north of LA. I'm about midway between Agoura hills and baja, but I think it was probably the baja quake I felt, since it was the stronger one, and I barely felt that one.
 

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