Why the New Madrid Fault is the Most Dangerous

The earthquake near New Salem, Illinois–on an extension of the New Madrid fault–is a reminder that, for all of the publicity that earthquakes in California get, the fault system that caused this quake is the most dangerous in the continental United States.

The reason is twofold.

First, California has an extensive system of faults.  While the number of faults increase the sheer likelihood of quakes, the faults also provide natural "firewalls" against seismic wave propagation from a quake, which is why quakes that occur in one place are felt in others.  In the case of the New Madrid fault, there are few faults surrounding it, so there’s little to stop the wave propagation.  This is why, during the major New Madrid quakes in 1811 and 1812, they were felt so far away.

The second reason is that the states surrounding the New Madrid fault have not been as proactive as California in preparing their structures for a seismic calamity. It’s true that, in recent years, they have taken steps to retrofit the major bridges and other structures for such an event, but upgrading the building codes to weed out unreinforced masonry structures–the worst type of structure in an earthquake–has been sorely lagging.  A parallel problem with timber structures exists down the Mississippi River, which are in turn unprepared to withstand calamities such as Hurricane Katrina.

One time I was reading an article in a technical journal about the New Madrid fault, and the researcher being interviewed frankly confessed that we really don’t know why there are earthquakes in the New Madrid region.  It’s a reminder that, for all of the confidence that we exude about our knowlege, there’s still a lot to learn about God’s creation, and a little humility–in addition to proper preparation–never hurt anyone.

One thought on “Why the New Madrid Fault is the Most Dangerous”

  1. We live on a dangerous planet. That’s easy to forget when truly hazardous events don’t occur very frequently. For a few people understanding the danger can come from standing close enough to a moving glacier to hear the grinding of the ice or seeing channeled scablands formed by the catastrophic release of water from a glacial lake, such as former Lake Missoula in the American northwest. Another thing to keep in mind: in the more settled parts of the world most people don’t think about how the walls of houses and window screens keep potentially dangerous wildlife, from hungry bears to disease-carrying insects, at bay. All that said, our world is also a magnificent creation, as we are reminded in Genesis (1: 31).

    For anyone wanting more information about specific earthquakes and their causes in the American Midwest the following links are a good starting place. In addition to discussing the underlying settings for the earthquakes, these pages also have links to the web pages of several scientific agencies with more detailed data.

    http://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone
    http://en.wikipedia.org/wiki/Wabash_Valley_Seismic_Zone
    http://en.wikipedia.org/wiki/April_18%2C_2008_Midwest_earthquake

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