Map of the area of the Aleutian Island arc discussed in the paper. Sections showing seismic activity observed by the local networks are indicated. The Border Ranges fault crops out on the Kenai Peninsula and Kodiak Island. Its position subsea is as given by Fisher and von Huene, 1984. Direction of convergence of the Pacific plate given by DeMets and coworkers (1990) is indicated, and where indicated the rate is 67 km/Ma for the eastern Aleutians and 82 km/Ma for the central Aleutians.

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