Earthquake in Southern Illinois

[C`gan]

http://earthquake.usgs.gov/eqcenter/...08/us2008qza6/

I felt it here in northern Indiana. Did anyone else?

[Mimir]

125 miles from epicenter and yup sure did

[AmonGwareth]

Woke me up here (St Louis).

[Mimir]

Ohhh right across the river from you.. can see the arch if stand on my roof.

[AmonGwareth]

Woot, just had a big aftershock. felt like a massive gust of wind shook the building.

[C`gan]

Yup, felt the aftershock up here, too.

It's very exciting for me since I went to college for geology and have my Bachelor of Science. I'm tying to keep up on the data coming in as much as possible.

Be sure to fill out the survey(s) on the USGS site about feeling it. That sort of empirical data does help with understanding earthquakes, particularly in this region where the fault line(s) are not as clear as in other seismic zones. If you look at the historical seismic map, you'll see that quakes in this region just north of the New Madrid line are just interspersed everywhere. There's no clear definitive single faultline or set of faultlines as in California.

That and the structure of the geology in this region (we have a basin and dome) can cause the P and S waves of the quake to be refracted and reflected so that different areas can get a stronger or weaker feeling of the event. So, the more pinpoints of data, the better.

[DharSii]

my friends said they felt it in east Tennessee i didn't though XP (was still asleep)

[Steelclaw]

Ground shaking? *yawn* </californian>


On a more serious note, I hope nobody here suffered any property or personal damage.

[Mimir]

Ground shaking? *yawn* </californian>


On a more serious note, I hope nobody here suffered any property or personal damage.

And as an FYI to those used to "quakes"

"...Regions with damaging shaking during the 1811 New Madrid earthquake (estimated magnitude near 8.0) and 1906 San Francisco earthquake (estimated magnitude 8.3). For the 1811 event, the shaking to the west of the Mississippi is estimated based on the observations to the east since the region was not yet settled (After Nuttli, 1981)..."

http://eqseis.geosc.psu.edu/~cammon/...intensity.html

C`gan may be better able to explaine why a quake in the midwest is worse.. I think it is because of our soil turns to quicksand or some such... but the above example shows that a lesser quake here is felt over a wider area than those on the west coast...C`gan? the floor is yours.

[Kala]

Be sure to fill out the survey(s) on the USGS site about feeling it. That sort of empirical data does help with understanding earthquakes, particularly in this region where the fault line(s) are not as clear as in other seismic zones.

Since C`gan didn't post a link to where you can fill out the survey, here it is. Please note that this survey is only for this particular earthquake.

[Pharcellus]

http://earthquake.usgs.gov/eqcenter/.../10/275_35.php

For those who want the data.

The reason midwest and east coast earthquakes are felt further away (and are often more damaging farther from the epicenter) is because of the Appalachian dome. The bedrock is very thick and transmits more energy with less loss over distance.

In contrast, the west coast is more fractured and has a less "solid" makeup.

Basically, take a block of clay/sandstone and hit it with a sledgehammer while touching the other side vs doing the same thing with a block of granite.

[Valornyx]

Ground shaking? *yawn* </californian>


On a more serious note, I hope nobody here suffered any property or personal damage.

Lol .. I'm in Taiwan - I'll see you and raise you .. but yes - I also hope that no one was hurt or lost anything important

[AmonGwareth]

One building suffered damage from what I hear, thats it. A 5.2 really isn't that huge, it was just felt over a wide radius affecting a few million people.

I think everyone gets used to something. Earthquakes if you are in a zone where they happen often... Myself, I kind of yawn at tornadoes. I mean, I am careful to protect myself, but they are old hat because I've lived with them for 30+ years.

Same thing with snow and ice and driving. I know people that panic at the mere thought of snow on the ground and having to drive.

The midwest, particularly Illinois and Missouri, only get a few earthquakes each year and most of them can't be felt. This one today was the largest in the region since 1968 if that tells you anything. Myself, this is only the third I've ever felt in this region (the others being in the early 90s).

[gopher65]

Yeah Amon, I think you're right. When I lived in Alaska earthquakes were considered pretty tame. In part because we were use to them, and in part because all of the structures were built to withstand significant shaking. IIRC there was a magnitude 6.x one while I was there, and it didn't make any news except the local stations. If a magnitude 6 happened where I am now, we'd see buildings collapsing:P. They just aren't built to handle lateral motion.

On the other hand we all snicker when we see how 1cm of snow in Oklahoma causes the governor to declare a state of emergency. It's all what you're use to, and what you're well prepared to handle.

[aine]

I didn't feel it in Florida, C`gan, (hehe), but my mom did, slightly, in Cincinnati, Ohio, if that helps to know. (I didn't add it to your poll, as it wasn't my experience, per se.)

[Silverblaze]

went to school in Carbondale, live in utica, home of the last earthquake IL had. I felt it and swore incoherently for a good minute.


The ground is not supposed to move!!!!

IL is one big fault line, but I was hoping to avoid all the unpleasantness.

[Mimir]

Wow Carbondale??? SIU? and you survived? LOL

Party On Dude or Dudette ...

Just kidding... or was I?