Reassessing the New Madrid Seismic Zone

Abstract

The central enigma of the mid‐continent region in the United States known as the New Madrid seismic zone (NMSZ; Figure 1) involves the mechanisms that give rise to recurrent great earthquakes far from plate boundaries. Given the lack of significant topographic relief that is the hallmark of tectonic activity in most actively deforming regions, most of us feel a need to “pinch ourselves to see if we're dreaming” when confronted with evidence that, at some probability levels, the earthquake hazard throughout the NMSZ is comparable to that estimated for the San Francisco Bay region. Although assessing the hazard in the NMSZ is in many ways more challenging than in the western United States, and the uncertainties are much greater, careful scientific study has led to a consensus on the issues most critical to seismic hazard assessment.