In July, 1988, the USGS simultaneously acquired 1100 km of marine multichannel seismic reflection and wide-angle reflection/refraction data along 6 profiles in the norhtern gulf of Alaska using the R/V Geotide operated by Digicon. These data were acquired using a large (7770 cu. in.) airgun array for the multidisciplinary Trans-Alaska Crustal Transect (TACT) study being conducted across Alaska. The reflection and wide-angle profiling in the Gulf of Alaska was designed to extend the deep crustal structure already mapped onshore by TACT to offshore regions and to map the crustal structure of the accretionary marin off southern Alaska to the Aleutian Trench.