A number of intraplate earthquakes ocurring in the western North Atlantic Ocean are located near the perimeter of the Bermuda rise. Focal mechanisms and depths of two earthquakes, November 4, 1976 (mb 5.1; M0=2.96 ¿1023 dyne cm) and March 24, 1978 (mb 6.1; M0=3.58¿1025 dyne cm), were determined using Rayleigh wave amplitude data in the period range 20--50 s. The 1978 earthquake occurred approximately 380 km southwest of Bermuda, near magnetic anomaly M4 (≈118 m.y. B.P.). The focal mechanism for the 1978 event is of thrust type and has model planes striking 340¿. The depth of this event is 6 km below the seafloor, near the local depth to Moho. The strike of the fault planes does not parallel the trends of either fracture zones (300¿) or magnetic lineations (035¿) in the area. The fault planes do, however, parallel the strike of a magnetic gradient in the epicentral area. The 1976 earthquake occurred approximately 300 km northeast of Bermuda, near Muir seamount. The depth of this event is 10 km below the seafloor. The available data are suggestive of one nodal plane striking between 320¿ and 340¿ and nearly parallel to the trend of Muir seamount and other volcanic features in the region. In contrast to the 1978 event, the 1976 earthquake appears to exhibit a significant component of strike slip motion. P axes of both mechanisms are subparallel to the direction of absolute plate motion for North America. We suggest, however, that strain release in the Bermuda rise area is not occurring along major fracture zones or topography parallel to seafloor spreading anomalies but rather on smaller-size structures. The stresses induced by variations of crustal thickness may be responsible for triggering interplate seismicity in this region.