[Paul R.]

Just what we don’t need...

Although it is a much different type of fault, I’ve always wondered of the big New Madrid quakes of 1811-12 were preceded by a ramp up of smaller quakes? I’ve never seen anything about that in the literature. (I’m in the region, which gets small quakes frequently.)

[Robert A Cook PE]

I am slightly south and east of you. Have felt Mag 2 and Mag 3 earthquakes in middle TN, north AL, north GA.

Concur - I have not heard about or read of oral reports of earthquakes other the New Madrid TN quake. South Carolina church bells were rung.

[ducttape45]

The New Madrid and Cascadia fault lines are the ones I have feared the most. Either one will cost untold billions in damage and huge losses of life. No one will be safe.

I am in north central Indiana but there are several small fault lines here that, if the New Madrid goes off, will go off and cause damage here as well. I've even felt tremors here over the past several years, small ones of course. Nothing like I felt when I stationed on Guam back in the 1980's. Those were fun watching my keyboard dance across my desk. The island never tipped over though. :-)

[gleeaikin]

It is quite likely that the New Madrid had some before quakes. It certainly had a lot of small quakes between the very big ones. Small population, limited information, although Audibon was collecting in the area and wrote something about it. One thing probably not heard here is that Caracas, Venezuela had a major quake during that cycle which killed around 20,000. In earlier centuries, Lisbon, Portugal was destroyed by a terrible tsunami, and of course also had quakes. About a month later, Boston had the worst quake ever recorded in that part of the country. I think some events in North Africa were also recorded around that time.

The Carolinas had a bad quake about 20 years after the Civil War, although not on the scale of New Madrid or San Francisco which occurred around 20 years after that.

It appears that some of these major events are regional in nature. When Mt. Pelee blew on the island of Martinique in 1902, the volcano on St. Vincent blew within the same 48 hour period. One captain at sea reported that the ocean suddenly dropped about 4 feet, and sharks were jumping out of the water because it got so hot.