When I hear the word “earthquake," my thoughts immediately turn to San Francisco, the San Andreas Fault, and, as of a few weeks ago, to the massive 7.0 earthquake that recently devastated Haiti.
I don’t generally think of the Mississippi Delta, even though this area has been the site of some seismically powerful quakes of the past 200 years. Notably, during the winter of 1811-1812, five earthquakes with magnitudes of greater than 8.0 racked the Mississippi Valley, changing the course of the Mississippi (some historical accounts claim the river ran backwards!), and ringing church bells as far away as Boston, Massachusetts.
Obviously, these historical earthquakes can hardly be compared to the tragedy currently unfolding in Haiti. The few buildings and people that were hurt in sparsely populated Mississippi during the 1800s is insignificant when we consider the thousands of homeless, injured, dead, and devastated piling the streets of Haiti today.
As in the 1800s, the Mississippi Valley lays atop the seismic New Madrid Fault. The fault extends across 5 states, running from Illinois to Arkansas, across some of the most economically impoverished areas of the United States. An earthquake in this now highly populated area would, according to a 2008 FEMA report, cause “widespread catastrophic physical damage, negative social impacts, and economic losses,” a far different result from the 1811 quakes.
So what is the likelihood of a quake happening in the Mississippi Valley? Unfortunately, it is difficult to know. Earthquakes are generally tough to predict, and the New Madrid Fault is especially tricky because it is a seismic zone that is not based on plate tectonics. Scientists have been speculating about the future of seismic activity at the New Madrid Fault for years. While some scientists predict a major quake in the central United States within the next 50 years, a recent study in Science, co-authored by Northwestern professor Seth Stein, suggests that seismic activity in the area may be quieting down.
In the aftermath of the Haiti earthquake, the New Madrid Fault has been unexpectedly quiet, leading to further concern and uncertainty surrounding the potential for future earthquakes. If we want to avoid the sheer devastation and surprise of an earthquake like we saw in Haiti this past week, we need to learn how to better predict earthquakes.
- blog authored by Rachel Smith