Scientific understanding of earthquakes in the New Madrid seismic zone has advanced greatly in recent years, but these advances have resulted in neither better assessment of seismic hazard and risk nor better mitigation policy. The main reasons for this are (1) misunderstanding about the National Seismic Hazard Maps and (2) confusion about seismic hazard and risk. Seismic hazard and seismic risk are two fundamentally different concepts, even though they have often been used interchangeably. Both are used differently in policy decision making, but seismic risk is the deciding factor, not seismic hazard.

Even though the input parameters are scientifically sound,...