Abstract
Fault plane solutions for eight earthquakes occurring in the northeastern United States have been determined using P-wave first motions and a computer algorithm for picking all valid solutions. The predominant mechanism in the area is thrust faulting, however the direction of the P axis is not consistent throughout the entire area. In central New England (Maine-New Hampshire), the P axis trends nearly E-W. In southeastern New England, the P axis trends N-S to NE-SW. In the Adirondacks region of New York, the P axis trends NE-SW as previously reported by Yang and Aggarwal (1981). Although the stress distribution appears to be complicated, as in the Central United States (Street et al., 1974), an underlying E-W compressive stress may exist in the New England area. These small earthquakes may represent the response to local stress concentrations.
