The New Madrid Fault is one of our region's biggest "known unknowns." And from an economic development perspective, that has been a problem.
The debate about the danger of the fault producing another massive earthquake like the trio of quakes known to have occurred in 1811 and 1812 has cooled somewhat from the relative hysteria of the 1990s.
Many will recall the media circus that surrounded self-proclaimed "climatologist" Iben Browning's prediction that tidal forces created a 50-50 chance that the New Madrid Fault would blow on December 3 or 4 of 1990. Former Paducah Sun columnist Bill Bartleman accurately described that episode as one of the low points in the history of news reporting, as the national media descended on New Madrid, unable to resist the fun of hyping a sensational albeit scientifically bankrupt story. It created a panic, allowing out-of-town hucksters to line their pockets with overpriced earthquake survival kits and causing schools to close as far away as eastern Kentucky.
While the Browning affair came and went, the notion that the fault would soon repeat the events of 1811 and 1812 lived on for a time. We've always been skeptical of that notion - not that the fault would not produce more earthquakes of some magnitude; but that it would produce substantially the same event, like clockwork, every 200 years or so.
Fortunately, there were other skeptics too. And if any good came out of the Browning affair, it is that the New Madrid Fault has been subject to much more scientific study in the past couple of decades, and the debate has shifted from one of when the next monster quake might come to a debate about whether the fault is actually dying.
One handicap of the analysis of New Madrid has been that most earthquake science and modeling is based on the study of tectonic plates such as those that create California's San Andreas Fault, which frequently produces earthquakes on the West Coast.
But as an Associated Press story in Friday's Paducah Sun points out, the New Madrid fault is an "enigmatic" fault. There are no tectonic plates opposing one another at the fault, and unlike the San Andreas Fault, which is near the surface, the New Madrid Fault is deep within the earth.
One school of thought now is that the temblors experienced in the New Madrid region since the 1811-1812 quakes are simply aftershocks from that quake, and that they represent a further easing of pressures in the fault that will ultimately lead to inactivity and the "death" of the fault.
Friday's AP story centered on a new study based on computer models that contends that the temblors are not aftershocks, and that the fault remains a danger. However, the story notes not all researchers are buying that, including Georgia Institute of Technology geophysicist Andrew Newman, who observes that the methodology of the study works well along tectonic plates but may not apply to an enigmatic fault like New Madrid.
The debate is important for our region, because for now construction codes in Paducah and elsewhere along the fault are subject to California-style seismic standards. That's costly and it has economic development consequences. The added cost of meeting seismic codes was a significant factor in USEC Inc.'s decision to build its next generation centrifuge plant in Ohio rather than Paducah. We are now seeing the consequences, as USEC winds down its Paducah operations, along with many of the company's 1,200 jobs here.
If the seismic danger is real, no rational person would question the tougher seismic requirements. But if the danger is not real, or even seriously overstated, standards need to be adjusted accordingly.
At present, the reality is no one really knows and regulators have chosen to err on the side of caution. The best we can all hope for is that more study and advances in sciences like geophysics will give us a clearer picture in the years ahead.