Figure 40. The U.S. EEZ Hawaii III Northwestern Hawaiian Ridge area GLORIA sidescan-sonar mosaic.

Background

The Hawaii III Northwestern Hawaiian Ridge GLORIA digital mosaic was the final area to be imaged and mosaicked for the U.S. Hawaiian EEZ area. Data for this region were acquired during six surveys during a consecutive three year time period from 1989 to 1991. When finished 22 50 m mosaics of approximately a 2-degree by 2-degree area were completed. The GLORIA image of the EEZ of the northwestern Hawaiian Ridge covers about 728,000 sq km of seafloor.

The first survey (F-13-89-HW) was conducted from November 28 to December 21, 1989. The area surveyed was the outer part of the remaining territorial EEZ on the south side of the Hawaiian Ridge on the eastern end at about 167^oW and extending to the limit of the EEZ beyond Kure Island.

The following two cruises (F-1-90-HW and F-2-90-HW) were completed consecutively from January 3 to 28, and January 29 to February 22, 1990. These cruises were run parallel to one another trending west-northwest and east-southeast south of the Hawaiian Ridge and north of F-13-89-HW to fill gaps left by previous cruises (Kayen and others, 1990; Pickthorn and others, 1991; Dadisman and others, 1992).

The three remaining cruises completed the survey of the northern area of the U.S. EEZ Hawaiian area. The cruises were completed between April 24 to May 19, 1991 (F-5-91-CP) and May 21 to June 15, 1991 (F-6-91-CP). The final cruise (F-10-91-HW) was completed from September 27 to October 29, 1991.

Figure 41. Map showing field activities for GLORIA sidescan-sonar data collection in the U.S. Exclusive Economic Zone (EEZ) Hawaii III Northwestern Hawaiian Ridge area.