Topic: I just felt my first earthquake...near Dallas/Fort Worth

[nincehelser]

Driving on I-35W, I stopped in Alvarado, TX to get something to eat.  Everyone's watching the weather about storms developing, then there was a loud noise a very brief period of shaking.  I thought it was a lightning strike on the building or possibly a tornado or truck.  Others were thinking it was an explosion (like West, TX had a while back).

Turns out it was a magnitude 4 about 2 miles deep in the Dallas/Fort Worth Area.  Venus, TX seems to be the closest town.  Happened just before 6:00PM.

[DanS]

Mag 4 was a pretty good shake I'd imagine. The most I've experienced (so far) was a 3.2 centered about 5 miles north of here. Weird feeling for sure.

[nincehelser]

Mag 4 was a pretty good shake I'd imagine. The most I've experienced (so far) was a 3.2 centered about 5 miles north of here. Weird feeling for sure.

It definitely got my attention.  I was very brief, though... maybe a second or two. 

This is only about 40 miles from where the West, TX explosion occurred, so many locals assumed something nearby blew up.

[BigOkie]

Mag 4 was a pretty good shake I'd imagine. The most I've experienced (so far) was a 3.2 centered about 5 miles north of here. Weird feeling for sure.

It definitely got my attention.  I was very brief, though... maybe a second or two. 

This is only about 40 miles from where the West, TX explosion occurred, so many locals assumed something nearby blew up.

The 5.6 I (and other north Oklahomans) felt in 2011 was the craziest thing I ever felt.  I was in my office at the house when I noticed my LED monitor buffeting back and forth.  Then stuff falling off cabinets.  Lasted for about 45 seconds.

About 40 minutes later I was sitting on the den floor (pier/beam house) and could feel an aftershock..it was moving the house side to side for about 30 seconds.  Unsettling.

That aftershock was a just a 3.9 but I could feel it better as I was butt on the floor.

[Bunty]

An interesting part of article linked below: "Oklahoma is a deep red Republican state and has been an industry bastion for decades. That has translated into significant political influence in Oklahoma’s state capitol. When Johnson Bridgwater of the Sierra Club, an environmental group, lobbied lawmakers recently on an energy issue, he was told they had been visited by 20 paid advocates — and that he was the only one not speaking for the oil industry."

If only the earthquakes would stop bothering us in the hot spots and lobby for us by centering under the State Capitol, then maybe something serious would be done.  Considering how most of these earthquakes from the hot spots are too weak to travel far, not much beyond the counties they originate,  I wouldn't be surprised legislators quite seldom feel any at the State Capitol when the legislature is in session.  So why should most of them care about doing something about the earthquakes?  For one exception, my rep has been taking the quakes more seriously than usual, but he's not going to be taking seriously.

http://www.ft.com/intl/cms/s/0/6fab1192-f30d-11e4-a979-00144feab7de.html#slide1

http://www.ardmoreite.com/article/20150423/NEWS/150429877/1999/NEWS

[CW2274]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

[Harryca]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

You don't mean the 1989 Loma Prieta quake do you?  I was working in San Ramon at the time and even though we were 70 miles from the epicenter, it felt like the whole building was going to come down and this was only a mag 6.9.  Everything was falling off the shelves, desktop computers and monitors were flying off the desks onto the floor, books falling out of bookcases and bookcases overturning, ceiling tiles falling everywhere.  I dove under my desk and rode it out for what seemed like forever.  And of course, there were the freeway collapses, freeway offramps compromised, a section of the Bay Bridge collapsed, buildings damaged, the big fire in the Marina District in SF.  It was a total nightmare.  If Oklahoma needs an example of what kind of damage can be caused by a mag 7.0, they don't need to look very far.

On October 17, 1989, at 5:04:15 p.m. (P.d.t.), a magnitude 6.9 (moment magnitude; surface-wave magnitude, 7.1) earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located at 37.04° N. latitude, 121.88° W. longitude near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco. The earthquake occurred when the crustal rocks comprising the Pacific and North American Plates abruptly slipped as much as 2 meters (7 ft) along their common boundary-the San Andreas fault system. The rupture initiated at a depth of 18 km (11 mi) and extended 35 km (22 mi) along the fault, but it did not break the surface of the Earth .

https://www.google.com/?gws_rd=ssl#q=1989+loma+prieta+earthquake

[WeatherHost]

I kind of wish they'd quit mislabeling these as Earthquakes and call the what they are ....  Frack-tures.

[CW2274]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

You don't mean the 1989 Loma Prieta quake do you?  I was working in San Ramon at the time and even though we were 70 miles from the epicenter, it felt like the whole building was going to come down and this was only a mag 6.9.  Everything was falling off the shelves, desktop computers and monitors were flying off the desks onto the floor, books falling out of bookcases and bookcases overturning, ceiling tiles falling everywhere.  I dove under my desk and rode it out for what seemed like forever.  And of course, there were the freeway collapses, freeway offramps compromised, a section of the Bay Bridge collapsed, buildings damaged, the big fire in the Marina District in SF.  It was a total nightmare.  If Oklahoma needs an example of what kind of damage can be caused by a mag 7.0, they don't need to look very far.

On October 17, 1989, at 5:04:15 p.m. (P.d.t.), a magnitude 6.9 (moment magnitude; surface-wave magnitude, 7.1) earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located at 37.04° N. latitude, 121.88° W. longitude near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco. The earthquake occurred when the crustal rocks comprising the Pacific and North American Plates abruptly slipped as much as 2 meters (7 ft) along their common boundary-the San Andreas fault system. The rupture initiated at a depth of 18 km (11 mi) and extended 35 km (22 mi) along the fault, but it did not break the surface of the Earth .

https://www.google.com/?gws_rd=ssl#q=1989+loma+prieta+earthquake

No sir, I had already been gone a year by then. This was "only" a 5.6 IIRC and didn't break out the tower windows, the 1989 one did.

[chief-david]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

Velocity of Common Rock Types[4]
[hide]Rocktype   Velocity [m/s]   Velocity [ft/s]
Unconsolidated Sandstone   4600 - 5200   15000 - 17000
Consolidated Sandstone   5800   19000
Shale      1800 - 4900   6000 -16000
Limestone   5800 - 6400   19000 - 21000   (holy cow, 21,000 ft per second)
Dolomite   6400 - 7300   21000 - 24000
Anhydrite   6100                   20000
Granite   5800 - 6100   19000 - 20000
Gabbro   7200                    23600

Thought about this when you said speed.  I remember speed when doing things with my honors class.

[CW2274]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

Velocity of Common Rock Types[4]
[hide]Rocktype   Velocity [m/s]   Velocity [ft/s]
Unconsolidated Sandstone   4600 - 5200   15000 - 17000
Consolidated Sandstone   5800   19000
Shale      1800 - 4900   6000 -16000
Limestone   5800 - 6400   19000 - 21000   (holy cow, 21,000 ft per second)
Dolomite   6400 - 7300   21000 - 24000
Anhydrite   6100                   20000
Granite   5800 - 6100   19000 - 20000
Gabbro   7200                    23600

Thought about this when you said speed.  I remember speed when doing things with my honors class.

It was incredibly fast. Upon reflection, I've should have said "at least" a few hundred miles per hour but certainly not those velocities.

[Bunty]

With thunder from a storm when a 3.1 earthquake happened at 6:19pm 6 mi. southwest of Stillwater, I might have mistook it for thunder.

[SlowModem]

So why should most of them care about doing something about the earthquakes?

The most powerful force in the universe is the dollar.

[SlowModem]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

Truly a Kodak moment.  That would have been an interesting video.

[SlowModem]

I kind of wish they'd quit mislabeling these as Earthquakes and call the what they are ....  Frack-tures.

Ha!  That's a good one!   

[CW2274]

Back in 1987 or 88 when I was working in a control tower in San Jose, I SAW the earthquake coming before feeling it. The shock wave, called a surface wave I believe, was visibly approaching from the NW at I'm guessing several hundred miles per hour. It looked just like an ocean swell but it was the ground. Without a doubt the most incredible natural thing I've ever witnessed, by far.

Truly a Kodak moment.  That would have been an interesting video.

Frankly, to me, "interesting" isn't even in the realm of what I witnessed. I saw something that was not only unbelievable, I never even knew it could exist.