1968 Illinois Earthquake - Future Threats

Future Threats

In 2005, scientists determined there was a 90% probability of a magnitude 6–7 earthquake in the New Madrid area during the next 50 years. This could cause potentially high damage in the Chicago metropolitan area which has a population near ten million people. Pressure on the fault where the 1811–1812 Madrid earthquakes occurred was believed to be increasing, but a later study by Eric Calais of Purdue University and other experts concluded the land adjacent to the New Madrid fault was moving less than 0.2 millimetres (0.0079 in) a year, increasing the span between expected earthquakes on the fault to 500–1,000 years. Scientists anticipating a future earthquake suggest the Wabash Valley Fault as a possible source, calling it "dangerous".

Douglas Wiens, a professor of earth and planetary sciences, reported: "The strongest earthquakes in the last few years have come from the Wabash Valley Fault", and said the fault needs more scientific observation. Steven Obermeir of the United States Geological Survey is one of several scientists who have found sediments suggesting Wabash Valley Fault earthquakes around magnitude 7 on the Richter scale. Michael Wyssession, an associate professor of earth and planetary sciences, denigrated the Madrid fault zone and said, "in 20 years there have been three magnitude 5 or better earthquakes on the Wabash Valley Fault. There is evidence that sometime in the past the Wabash Valley Fault has produced as strong as magnitude 7 earthquakes. On the other hand, the New Madrid Fault has been very quiet for a long time now. Clearly, the Wabash Valley Fault has gotten our deserved attention."