The 8.1-magnitude New Madrid earthquake of 1812 — the strongest quake ever recorded in the continental U.S. — could very well be repeated within the next 50 years, geologists have confirmed:
Strain is building on a fault near Memphis, Tennessee that was the site of… [the] colossal earthquake that caused damage from South Carolina to Washington D.C. and temporarily reversed the course of the Mississippi River nearly two centuries ago. …
The odds of another 8.0 event within 50 years are between 7 and 10 percent, geologists said today. … A lesser but still damaging quake of magnitude 6 or greater has a 90 percent chance of striking in the next five decades. …
The assessment, based on new data from a recently installed array of sensors, puts to rest a 1990s claim that strain was not increasing.
An 8.0+ earthquake “would rock the entire eastern half of the country” — because the sparsity of fault lines in the East and Midwest makes the crust smoother and therefore seismic waves travel much farther than they do in the West — and “prove devastating to the local region.”
P.S. More on why Eastern quakes are worse than Western quakes:
When the ground does shake in the East, the potential for destruction and loss of life is far greater. Scientists aren’t entirely certain why, but they know that seismic waves in the East travel farther and pack more destructive punches. One explanation is that eastern geology is older and simpler, with fewer faults in the ground to slow the travel of quake waves. The ground is also drier and thus may propagate waves more efficiently.
Here’s a great graphical representation of the difference.
And of course, there’s also the fact that Easterners and Midwesterners are less prepared, buildings are less likely to be earthquake-proof, etc.
There are plenty of alarmist predictions about the “next New Madrid,” like this…
The next time the New Madrid Fault produces [an 8.0+] quake, it is estimated 60 percent of Memphis will be devastated, leaving $50 billion in damage and thousands of dead in its wake. Memphis, you see - like Armenia - has looked down the barrel of a loaded seismic gun for decades, but has done virtually nothing to move out of the crosshairs.
…and this:
Such an earthquake would wreak havoc in large population centers that did not exist 189 years ago, including Memphis, St. Louis, Indianapolis, Paducah, Kentucky, and Evansville, Indiana.
“There would be damage in 15 to 20 states in such an event, and there would be many fatalities,” says Stewart. “Bridges would collapse, hazardous materials stored up and down the river could be released, and there would be fires.”
There is good reason for the bleak predictions, though. The 1812 quake was “felt all the way from the Rocky Mountains…to the Eastern Seaboard, and from Quebec to Cuba.” It “created a number of lakes, and rang church bells in Boston. The earth shook so noticeably in Washington, D.C., that President James Madison and his wife Dolly thought the White House was being burglarized.” Also, “large areas sank into the earth…and forests were destroyed over an area of 150,000 acres. Many houses at New Madrid were thrown down. ‘Houses, gardens, and fields were swallowed up,’ one source notes. But fatalities and damage were low, because the area was sparsely settled then.”
P.P.S. Even a 6.5 quake would cause a whole lot of shakin’ goin’ on. Predictions for such an event place South Bend in the IV zone on the Mercalli Intensity Scale, which means: “Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.” Sounds like fun! :)
Actually, a Mercalli intensity of IV is roughly what I experienced while at USC during both the powerful but distant Hector Mine quake of October 16, 1999 and the weak but nearby Beverly Hills tremor of September 9, 2001. (I was asleep in Trojan Hall during the former — the shaking woke me up — and I was studying in the basement of the newly earthquake-retrofitted Doheny Library during the latter.)
Not surprisingly, an 8.5 quake would produce a lot more shaking; according to these maps, it would put South Bend in the VI zone: “Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.” Still not so bad… but in Indianapolis, it definitely wouldn’t be any fun: “Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.” And closer to the epicenter? Fuggedaboutit.
June 23rd, 2005 at 1:38:32 am
Wah wah wah. “Every recorded”? Hmmmm….
June 23rd, 2005 at 2:00:02 am
Thanks, I fixed it…
June 23rd, 2005 at 2:04:07 am
I think I recall reading on this blog but a few days ago some disdain about us Westerners and our willingness to put up with earthquakes….
June 23rd, 2005 at 2:07:47 am
No, no, it was more of disdain at your tendency to laugh at us Northeasterners for putting up with snow.
June 23rd, 2005 at 3:43:44 am
Oh, Mike - we have *MANY* reasons to laugh at those in the north-east of this continent !
June 23rd, 2005 at 6:38:32 am
Wah wah wah. “Every recorded”? Hmmmm….
June 23rd, 2005 at 7:00:02 am
Thanks, I fixed it…
June 23rd, 2005 at 7:04:07 am
I think I recall reading on this blog but a few days ago some disdain about us Westerners and our willingness to put up with earthquakes….
June 23rd, 2005 at 7:07:47 am
No, no, it was more of disdain at your tendency to laugh at us Northeasterners for putting up with snow.
June 23rd, 2005 at 7:31:02 am
Yes everyone, the evil bad earthquake is coming! Fear it! It will kill your family! Destroy your homes! Drown your puppies! RUN FOR YOUR LIVES!
June 23rd, 2005 at 8:43:44 am
Oh, Mike - we have *MANY* reasons to laugh at those in the north-east of this continent !
June 23rd, 2005 at 12:31:02 pm
Yes everyone, the evil bad earthquake is coming! Fear it! It will kill your family! Destroy your homes! Drown your puppies! RUN FOR YOUR LIVES!
June 23rd, 2005 at 12:39:51 pm
Mike, I love snow–in the mountains, where you can do something useful with it. Clogging up cities and driveways though? Lame.
In any case, now it looks like much of the East gets snow, hurricanes/tropical storms, tornados, and now devastating earthquakes too! I think I can live just fine with earthquakes, floods, fire, and smog.
June 23rd, 2005 at 3:39:39 pm
Actually, most of the East that gets hurricanes doesn’t get snow, and vice versa. Hurricanes are mostly a danger Virginia and southward. Snow hits those places in very limited doses. And tornados are more central Midwest than East, really–eastward and northward of Ohio see very little in the way of tornados. My personal fear of an earthquake back East is one hitting a secondary fault line and dumping the contents of Love Canal into the Great Lakes, thereby all-but-destroying one the of the world’s largest freshwater systems.
June 23rd, 2005 at 4:25:46 pm
Destruction, woohoo!!!
:-)
Mike, if it’s east of the Rockies, it’s the Midwest, and if it’s east of the Mississippi, it’s the East.
June 23rd, 2005 at 5:39:51 pm
Mike, I <i>love</i> snow–in the mountains, where you can do something useful with it. Clogging up cities and driveways though? Lame.
In any case, now it looks like much of the East gets snow, hurricanes/tropical storms, tornados, and now devastating earthquakes too! I think I can live just fine with earthquakes, floods, fire, and smog.
June 23rd, 2005 at 7:46:52 pm
Didn’t they predict this would happen about 5 years ago? I seem to remember it being a big topic on art bell, and then disappearing after it didn’t happen on schedule.
Don’t forget the Yellowstone caldera that will blow-any-day-now and destroy all life on earth as we know it.
Yawn….
June 23rd, 2005 at 8:38:14 pm
OK, Andrew, let’s go with that definition. Here’s tornado alley. Note how little of it falls in your definition of East. :)
June 23rd, 2005 at 8:39:39 pm
Actually, most of the East that gets hurricanes doesn’t get snow, and vice versa. Hurricanes are mostly a danger Virginia and southward. Snow hits those places in very limited doses. And tornados are more central Midwest than East, really–eastward and northward of Ohio see very little in the way of tornados. My personal fear of an earthquake back East is one hitting a secondary fault line and dumping the contents of Love Canal into the Great Lakes, thereby all-but-destroying one the of the world’s largest freshwater systems.
June 23rd, 2005 at 9:25:46 pm
Destruction, woohoo!!!
:-)
Mike, if it’s east of the Rockies, it’s the Midwest, and if it’s east of the Mississippi, it’s the East.
June 24th, 2005 at 12:46:52 am
Didn’t they predict this would happen about 5 years ago? I seem to remember it being a big topic on art bell, and then disappearing after it didn’t happen on schedule.
Don’t forget the Yellowstone caldera that will blow-any-day-now and destroy all life on earth as we know it.
Yawn….
June 24th, 2005 at 1:38:14 am
OK, Andrew, let’s go with that definition. <a href=”http://www.tornadochaser.net/tornadoalley.jpg”>Here’s</a> tornado alley. Note how little of it falls in your definition of East. :)
June 24th, 2005 at 2:33:48 am
…And in that part of the East wherein tornados are slightly more rare, they get snow. So what’s your point again? :-P
June 24th, 2005 at 3:36:55 am
Slightly more rare? Ha! Tornados over land in NY and New England are pretty darn rare events, Andrew. My point is that you basically get either snow or tornados, not both, at least not in what you’ve declared to be the East. As is evidenced by the comment “Actually, most of the East that gets hurricanes doesn’t get snow, and vice versa”.…
June 24th, 2005 at 7:33:48 am
…And in that part of the East wherein tornados are slightly more rare, they get snow. So what’s your point again? :-P
June 24th, 2005 at 8:36:55 am
Slightly more rare? Ha! Tornados over land in NY and New England are pretty darn rare events, Andrew. My point is that you basically get either snow or tornados, not both, at least not in what you’ve declared to be the East. As is evidenced by the comment <i>”Actually, most of the East that gets hurricanes doesn’t get snow, and vice versa”.</i>…