Data from earthquakes occurring in northern Alaska collected by the Geophysical Institute of the University of Alaska, Fairbanks, have been reprocessed using a seismic velocity model developed for the Dall City and Fort Yukon areas of north central Alaska. A study of the relocated events shows that microearthquakes occur in a zone roughly parallel to, but south of, the crest of the Brooks Range. The events also show that the Kobuk, central Kaltag, Porcupine, Dall, Rampart, northwest Tintina, and Eskimo Lakes faults in northern Alaska and northwest Canada are seismically active, with the Eskimo Lakes fault being most active. Eight new focal mechanisms were determined for northern Alaska which show strike-slip faulting south of the Brooks Range. This movement is consistent with the known movement on the associated faults. The orientation of the pressure axes derived from these and other fault plane solutions is consistent with Pacific-North American plate convergence. Large-scale shearing appears to extend northward from the Pacific-North America transform boundary into arctic Alaska and allows the interpretation that the Seward Peninsula extensional zone is a large-scale pull-apart feature. ¿ American Geophysical Union 1988