5.6m Oklahoma Earthquake

[KevOwensby]

Felt it in Topeka, KS at 10:55pm. My first earthquake! Ugh... still shaking. Hearing of a lot of damage just east of OKC. Anyone else feel it?

[Al]

was felt as far south as San Angelo, Texas. this is the second quake we've felt this year.

[phw115wvwx]

A fair amount of damage is being reported in Oklahoma City according to TWC.  Hope everyone is okay.  What I thought were a bunch of aftershocks appear to be a bunch of precursor tremors leading up to this one tonight.

[KevOwensby]

I was thinking the 4.7 this morning was the main earthquake and everything through the day today were aftershocks. I'm hoping this was the "big one" because I'm still shaking and freaked out. My bed started moving like I was shaking my leg and then I started hearing rattling and then felt a jolt, my dog jumped up so I jumped out of bed and yelled "Oh my god, earthquake!" and my friend/roommate jumped out of her bed and we ran into the hallway to run outside. lol Then it stopped and we came in to my room and sat here watching the news and checking social media and the USGS site waiting for it to pop up.

[Trevor]

The NMSZ (New Madrid Seismic Zone) is nearby this area. Could these possibly be foreshocks to the 'big one', a repeat of 1811-1812? If it is, the 'big one' could cause some serious damage to Downtown Memphis and even Southaven.

[WeatherWitness]

As I said in the PBS, I was not inside any building when this happened last night, but was walking right next to my 12-story dorm building, literally a few feet away from going inside.  Suddenly, I heard a horrible "crackling" of bricks like the entire building was going to collapse.  When I saw everyone running outside, I knew something had to be wrong.  I can't really say I felt anything beneath my feet, though.

And to answer you Kevin, Patrick said that the 4.8 magnitude earthquake from 2:12 am Saturday morning was probably a "precursor" to the real one Saturday night.  I don't think aftershocks are supposed to be stronger than the real thing.

[KevOwensby]

And to answer you Kevin, Patrick said that the 4.8 magnitude earthquake from 2:12 am Saturday morning was probably a "precursor" to the real one Saturday night.  I don't think aftershocks are supposed to be stronger than the real thing.

Okay, let me rephrase... up until the 5.6 at 10:53pm I was thinking everything through the day was an aftershock.

[Localonthe8s]

Could these be precursors to an even larger quake? One has to think of the proximity of the New Madrid Fault..

[WeatherWitness]

Could these be precursors to an even larger quake? One has to think of the proximity of the New Madrid Fault..

Oh, I certainly hope not.  But who knows?  Like I said earlier, I agree with Patrick that the 4.8 magnitude earthquake Saturday morning was definetely a precursor to what happened last night.   But if Vic is correct and both of these are precursors to a future incident, I don't even want to think about that.   The one last night was strong enough and caused some damage (not where I am, but in other areas of Oklahoma).

[Donovan]

Wow this is a major shock to me (no pun intended). I live within miles of the "Fault" here near Charleston, SC  and with all of these earthquakes going on I'm hoping we don't get one, we're way over due. I hope anyone in the Quake was okay, I have yet to see any damage as I just got in.

[Evan2015]

Yes, the New Madrid is due, the largest earthquake since 1811-12 was a 6.6 in 1895. USGS says there's a 10% chance of a quake comparable to the 1811-12 quakes in the next 50 years on the NMSZ. However, I'm slightly more concerned with the closer Wabash Valley Seismic Zone on the IL/IN border...

[yourweathertoday]

The NMSZ (New Madrid Seismic Zone) is nearby this area. Could these possibly be foreshocks to the 'big one', a repeat of 1811-1812? If it is, the 'big one' could cause some serious damage to Downtown Memphis and even Southaven.

Usually, if the "big one" is going to happen, there are numerous small (and small being 2.1, 1.9, etc) quakes-as well as microquakes-leading up to it, NOT moderate quakes in the 4-6 magnitude level. These larger quakes (4.7 and 5.6) relieve tension on the fault, meaning it's less likely for the "big one" to occur right now.

[WeatherWitness]

I'm probably posting in this thread too much, but is there any relation to damage done by an earthquake and its magnitude?  I was surprised to find out the magnitude was a 5.6, because I didn't notice any damage (or even shifting of objects in my dorm room).  Nothing fell off desks that I noticed, but with an earthquake this strong, you would think there would have been some noticeable "movement," right?

[yourweathertoday]

I'm probably posting in this thread too much, but is there any relation to damage done by an earthquake and its magnitude?  I was surprised to find out the magnitude was a 5.6, because I didn't notice any damage (or even shifting of objects in my dorm room).  Nothing fell off desks that I noticed, but with an earthquake this strong, you would think there would have been some noticeable "movement," right?

While a 5.6 is a large(er) quake, it's strength is puny compared even to a 6.0. I believe for each number you go up the scale (eg. 5.0 to 6.0) the strength increases 1000x. It's on the internet somewhere. California routinely has quakes in the 5.0 ranger, very little damage.

[phw115wvwx]

Andy and Max, the Richter scale is a logarithmic scale based on the amplitude of the shaking, which gets recorded on a seismograph.  Since it's a logarithmic scale, every number up in magnitude means it's 10 times larger in amplitude of shaking.  Thus, a 8.0 quake will be 10 times more amplitude of shaking than a 7.0, 100 times more than a 6.0, and so forth.

However, energy is not the same relationship.  It works out that every two magnitudes up is 1,000 times more energy.  Thus, a 8.0 quake generates 1,000 times more energy than a 6.0, one million times more energy than a 4.0, and so forth.  Hope that helps!  I used Wikipedia to make sure I had the numbers in my head correct before quoting them here.