Geology News

Posted on Friday 18 April 2008 by Dave Schumaker

Wow, good morning Illinois. A decent sized earthquake measuring M5.2 � hit the midwest early this morning. According to CNN, there were only reports of minor damage, though some news organizations are showing pictures of rubble in the streets of� Louisville, Kentucky.

The location of the epicenter appears to be quite a ways from the New Marid fault zone.

Source: USGS

It’s an interesting coincidence, considering I just read about� this study� that downplayed the hazards posed by earthquakes in the midwest. Ouch! The study was conducted by researchers at Northwestern University and appears in the latest Bulletin of the Seismological Society of America.

“What we’re saying is that this may be nowhere as serious a problem as you’ve been told, and you don’t need to prepare in St. Louis the way we do in Los Angeles, because that may be doing more harm than good,” he added.

The desire to prepare is understandable, given the devastation caused by the last major earthquakes in the New Madrid zone in 1811 and 1812, and in Charleston in 1886. The 1811-1812 New Madrid earthquakes uprooted entire forests and changed the course of the Mississippi River. The Charleston earthquake killed more than 60 people and caused damage to nearly every structure in the city, traces of which can still be seen today.

To prepare for the potential dangers of similar severe quakes in the future, seismologists construct hazard maps, which predict the extent of earthquake shaking that has a certain probability of occurring in a geographical area. The hazard maps take into account the possible magnitude of the next earthquake, the likely ground shaking, the time window in which the next quake is likely to occur, and whether earthquakes are time-dependent or time-independent processes.

This article, about the potential for earthquake damage in Lousiville, Kentucky was posted today as well.

[Via USGS]