Earlier this year, several small quakes were centered near the New Madrid fault in southeast Missouri, including some that were felt in parts of Missouri, Arkansas, Tennessee and Kentucky, according to the U.S. Geological Survey. No damage was reported.
Another well-known fault line is located in New York City. It crosses Manhattan from the Hudson River to the East River, running approximately along 125th Street.
The Ramapo Fault, another New York Metro-area fault line, runs 70 miles through New Jersey, New York and Pennsylvania.
The fault has been quiet for about 200 years, which is part of the problem, seismologists say.
"We know in the future at some point an earthquake is going to occur but we don't really understand the rules of the game yet in this area, so we can't come with numbers and specifically tell you what the hazard is going to be," Leonardo Seeber, a research scientist at the Lamont-Doherty Earth Observatory at Columbia University in New York, said.
The Associated Press and Lyneka Little contributed to this story.