[sailordave]

Read that there were minor earthquakes in central Arkansas. Were they enough to be felt? How close were they to the New Madrid zone?

[whatever you want]

Originally Posted by sailordave

Read that there were minor earthquakes in central Arkansas. Were they enough to be felt? How close were they to the New Madrid zone?

Here's a good site to save on your favorites Dave.I used it quite a bit a few months ago when we were getting so many quakes around here.

Welcome to the U.S. Geological Survey Earthquake Hazards Program

[Bail_Khan]

I remember there was a show on the history or discovery channel about the faultline that runs through east arkansas west tennesse area. It's just a matter of time before it hits, but it probably won't hit in our lifetimes. If it did though it would be devastating because of the kind of soil we have and because our structures weren't built with earthquakes in mind.

[RogMar]

Originally Posted by Bail_Khan

It's just a matter of time before it hits, but it probably won't hit in our lifetimes. If it did though it would be devastating because of the kind of soil we have and because our structures weren't built with earthquakes in mind.

Among the geologists that I have read weighing in on this, the popular opinion is that we are *way* past due date, and it's an "any day now" thing.

Then....there's the school that comes in exactly as you said....won't be in our lifetime.

Geologists, IMHO, are no more competent with the facts of history as are Wall St. forecasters.

On the damage front, there was recently an article in the papers, giving a forecast on if Marked Tree was the epicenter, and it was either 6.7 or 7.2 (one of the two).

According to them, bad day if you own real estate there, but the forecasted damage/death into Sharp and Izard county, my area, was negligible, and I'm not that far away from there.

IIRC, they forecasted 2 deaths in southern Sharp, and none in Izard.

If I were east of Baxter county, I wouldn't plan on it making ripples in my martini.

In the end, Bail, I think it's a toss up, ya know?

Those tremors near central AR got the watchers by surprise, and articles say they're in the process of putting sensors in the central/NWA are to check activity there.

Personally, I'm looking forward to the overnight transition to lakefront property.

Maybe oceanfront when CA goes bye-bye.

[Fleet]

Originally Posted by RogMar

Maybe oceanfront when CA goes bye-bye.

Hopefully, you are just joking.

California is not going anywhere. California has had quite a few 7+ magnitude earthquakes and nowhere did land disappear or subside. Because most of the major faults in California are horizontal-type ones.

[RogMar]

Originally Posted by Fleet

Hopefully, you are just joking.

California is not going anywhere. California has had quite a few 7+ magnitude earthquakes and nowhere did land disappear or subside. Because most of the major faults in California are horizontal-type ones.

Yes.........joking.

It would take a lot more than a plate shift to slide that coastal area into the sea.

[Fleet]

Originally Posted by RogMar

Yes.........joking.

It would take a lot more than a plate shift to slide that coastal area into the sea.

Yeah, a lot more!
Glad to see you don't believe in those doomsday scenerios.

[Bail_Khan]

Yes I remember some of the geologists on the show were saying the quake was long overdue now that you mention it rogmar. There will be definately be a another big one though, only a matter of when.
In NE Arkansas there is supposed to be big sandhills that were caused by a previos earthquake.

[OA 5599]

Originally Posted by Bail_Khan

Yes I remember some of the geologists on the show were saying the quake was long overdue now that you mention it rogmar. There will be definately be a another big one though, only a matter of when.
In NE Arkansas there is supposed to be big sandhills that were caused by a previos earthquake.

There will indeed be another big one. The largest of the New Madrid earthquakes of 1811-1812 have been estimated to be around a 8.0 on the Richter scale. Due to the thinner crust in the central US compared to somewhere like California, the earthquake waves also travel a lot farther, so the area affected will be hundreds of miles across. Additionally, many of the flat-lying areas consist of weak sandy and silty soil which can easily turn into a liquid during an earthquake. Add in infrastructure that isn't designed for earthquakes (minus a few seismic retrofits on bridges and some newer structures), and you have a giant disaster.

There aren't any sand hills caused by the earthquakes that I'm aware of, but there have been many sand boils found across the area. Sand boils occur when a wet layer of sand underground is shaken so violently during an earthquake that it builds up high pressure, acts as a liquid, and explodes through the surface and "boils".

As far as being overdue for a big one, I *think* the return period for large earthquakes in the New Madrid seismic zone is around 500 years, and if so, all is well. However, predicting earthquakes with any accuracy is pretty much impossible, so it could happen tomorrow or in 200 years. Due to thick bedrock and thin, strong soils, most of the Ozarks will be relatively undamaged after a large earthquake in the New Madrid zone.

[Aporkalypse]

The recent quakes had nothing to do with the New Madrid but seem to be related to a local effect near Hot Springs and they are very low magnitude. A geologist I saw interviewed said they were surprised by it but thinks it may have to do with the heating of water from the Springs themselves and the effect it has on the crust in certain places. If that's the case only very minor quakes would occur in that area, not enough to do any damage.

Little Rock and Hot Springs didn't even have seismographs as it's very unusual for something to register here, it's far from the New Madrid fault. They're getting one.

As for the New Madrid, I have healthy respect for that kind of damage that can do. Little Rock is thankfully far enough away it won't get the brunt of it but apparently Memphis is at significant risk.