Central US faces real threat of quake, concludes expert panel

Science : In a recent report, an eight-member panel convened by the National Earthquake Prediction Evaluation Council, which advises the US Geological Survey (USGS), concluded that the New Madrid fault system is at significant risk for severe earthquakes. Quakes along the 150-mile-long fault can potentially threaten the US states of Illinois, Indiana, Missouri, Arkansas, Kentucky, Tennessee, and Mississippi. The panel recommended that construction in those states should continue to meet quake-resistant standards. But seismologists debate the degree of risk. Recent GPS measurements of land shifts show that very little crustal deformation has occurred in the area. Seth Stein of Northwestern University believes that the lack of crustal deformation indicates that stress in the New Madrid fault has wound down and that consequently there is little risk of earthquakes. The USGS advisory panel, however, wasn’t sanguine about taking that evidence as proof of reduced risk to the area and will stick with its assessment, at least until more data become available.