Another study by the Mid-America Earthquake Center last year estimates that nearly 750,000 buildings would be damaged, 3,000 bridges would potentially collapse, 400,000 breaks and leaks to local pipelines and $300 billion in direct damage and $600 billion in indirect losses would occur.
"Although Memphis is likely to be the focus of major damage in the region, St. Louis, Mo., Little Rock, Ark., and many small and medium sized cities would also sustain damage, " the U.S.. Geological Survey found.
A 2008 report released by FEMA found that a 7.7 scale quake would cause "widespread and catastrophic physical damage" in this region. The FEMA report offered the probability of a major quake of 7.5 to 8.0 to be somewhere between 7 and 10 percent probability. The probability of a quake of 6.0 or greater is higher is 25 to 40 percent.
The government is planning some mock training and preparedness exercises this spring.
South Carolina is home to an active fault line, which could also produce a catastrophic earthquake.
A quake in Charleston in 1886 was a magnitude 7.6. That city in 2008 had a population in excess of 348,000. Much of that state's coastal area is at risk.
Both Hawaii and Alaska are in the red danger zone in terms of massive earthquakes.
A report by the New York Consortium for Earthquake Loss Mitigation stated that , "In past centuries, earthquakes with Magnitude 5.0 have occurred about every 100 years in the New York City area. Modern New York City is ill prepared even for such moderate events. Although New York City is a region with low seismic hazard - meaning there are infrequent damaging earthquakes - it actually has high seismic risk because of its tremendous assets. The extreme concentration of buildings, and the fragility of its structures, most of which haven't been seismically designed, mean that even a relatively minor quake could cause major damage." Add subways and tunnels to the list of problems in New York. The area of the city most susceptible to damage would be the Upper East Side.
For more on fault lines within the United States, Click HERE.
As for U.S. government preparedness, Congress requested a national response plan for natural disasters from FEMA in 2006, after Hurricane Katrina and the resulting floods. But the comprehensive plan has not yet been completed.
"Until such a framework is in place, FEMA will not have a basis to operationalize and implement its conceptual approach for assessing local, state, and federal preparedness capabilities against capability requirements to identify capability gaps for prioritizing investments in national preparedness," according to the government's nonpartisan watchdog, the General Accounting Office, in an October 2010 letter to Congress.