Seismicity in the Area Surrounding Two Mesozoic Rift Basins in the Northeastern United States

Abstract

Seismologists have long sought to discern the cause(s) of earthquakes in the greater New York City (NYC) area. After decades of research on this topic, however, there are still many unanswered questions. Seismicity in the NYC area seems to be related in some way to the locations of Mesozoic rift basins (MRBs). This pattern might be a localized expression of the more global tendency of large earthquakes in stable continental interiors to occur in crust that has been stretched or extended at some time in the geologic past. This paper has three objectives: (1) It is a review of some of the well-known hypotheses that have been proposed to explain why earthquakes occur in the northeastern United States in general, and in the NYC area in particular. This review provides a background, and places this study of earthquakes in the NYC area in a more general context. (2) It is also a summary of the network seismicity in the NYC area. The network data are compared with the historical record of seismicity, and we demonstrate that there is a correlation between the network and historical seismicity. The earthquake process in the study area, therefore, appears to be stationary on the time scale of a couple of centuries. (3) Given this result, we use the network data as a “snapshot” of this earthquake process to test the hypothesis that there is a correlation between earthquake locations and the two MRBs in the study area, the Newark and Hartford basins.