USGS: Massive 7.7 Quake Would Rattle Missouri 3 Minutes

Having grown up in Missouri and being an earthquake nerd, I have studied just about every aspect of what a major quake along the New Madrid Fault would do, but it wasn't until now that I found a simulation run by the USGS that shows the state would likely shake for 3 minutes during a 7.7 magnitude quake.

There is a fascinating animation created by the USGS of a magnitude 7.7 quake along the New Madrid Fault in southern Missouri. They say it reveals a "long-period ground shaking expected for a large earthquake in the New Madrid seismic zone". They add that "the relatively unconsolidated material in the Mississippi embayment amplifies the ground shaking and also traps seismic energy to prolong the duration of ground shaking".

Here's what that would look like as the clock ticks. This is 8 seconds in after a 7.7 New Madrid quake.

The shaking extends around the 20 second mark.

Within 45 seconds, the impact would shake the St. Louis, Missouri region.

Within one minute, even more of Missouri and Illinois would be affected.

The entire New Madrid Seismic Zone would be suffering devastation by the minute and a half mark.

The USGS simulation estimates that Missouri and southern Illinois would feel the shake of a 7.7 magnitude quake for at least 179 seconds.

What are the odds of a 7.7 magnitude New Madrid earthquake?

According to the USGS, there is a 7 to 10% chance of 7.5 to 8.0 magnitude New Madrid quake happening in the next 50 years. What we really should be prepared for is a much more likely 6 magnitude quake which the USGS says has a 25% to 40% chance of happening during the same time period. It's another reminder that we must always be quake-aware in Missouri.