Previous earthquakes may have hinted at this

Mar 26, 2009 10:29 GMT  ·  By
The New Madrid fault line is only a small one, compared to the most massive tectonic plates
   The New Madrid fault line is only a small one, compared to the most massive tectonic plates

According to new scientific studies conducted on the Midwest seismic fault in the United States, the hole in the ground that has prompted concerns of a catastrophic earthquake sometime this century seems to be actually closing rather than becoming more active. The once-active area, known as the New Madrid fault system, may change the way we view seismic activity in the middle of the continent, the researchers behind the new investigation say.

“GPS technology can measure movement to the thickness of a fishing line,” Seth Stein, one of the seismologists at Northwestern University in Evanston, Illinois who have participated in the study, shares. He adds that the investigation team has used GPS sensors mounted on nine locations along the fault over the past eight years, in an attempt to monitor any possible movements of the ground and try to ascertain the future development of the situation.

Such studies are of paramount importance, on account of the vast extent of the fault line, which spreads over Missouri, Tennessee, Arkansas, Illinois, Indiana, Kentucky, and Mississippi. The worries prompted by increased activities in the area have not been without reason, as a 2008 tremor, rated to have had 5.2 degrees on the Richter scale, has been felt from Kansas to Georgia, even though it has taken place in the northeastern part of the fault.

“Building up energy for an earthquake is like saving money for a big purchase. You put money in over a long period of time and then spend it all at once and have to start saving again. The slower the ground moves, the longer it takes until the next earthquake, and if it stops moving, the fault could be shutting down. We can't tell whether the recent cluster of big earthquakes in the New Madrid is coming to an end. But the longer the GPS data keep showing no motion, the more likely it seems,” Stein stresses.