Figure 16. The U.S. EEZ Aleutian Arc area GLORIA sidescan-sonar mosaic south of the Aleutian Islands.

Background

The GLORIA data for the U.S. EEZ south of the Aleutian Islands, referred to as the Aleutian Arc survey, were acquired during five cruises completed in 1987 and 1988. The first two cruises, F-2-87-AA and F-3-87-AA, done in 1987 surveyed the western Aleutian Arc (Karl and others, 1987; Edwards and others, 1988). The remaining three cruises (F-7-88-AA, F-8-88-AA and F-9-88-WG) were conducted in 1988 and surveyed the central and eastern portions of the Aleutian Arc. The second 1998 cruise (F-8-88-AA) (Vallier and others, 1989) focused on a survey of the Aleutian Arc, however the easternmost portion of that survey extended outside of the Aleutian Arc survey area and into the western edge of the Gulf of Alaska study area. The final cruise (F-9-88-WG) focused on the Gulf of Alaska though a small portion, approximately 8,800 square kilometers (sq km), and included the Aleutian Arc area to complete the mosaic.

The completed GLORIA sidescan-sonar mosaic south of the Aleutian Islands covers approximately 843,000 sq km of seafloor.

Figure 17. Map showing field activities for GLORIA sidescan-sonar data collection in the U.S. Exclusive Economic Zone (EEZ) Aleutian Arc area.