SOJN05MV Sojourn Expedition Leg 05 - Cruise Data. In Data from Scripps Research Expeditions 1953-2005

Locate and survey a number of potential sites for future ocean drilling in the off-axis regions of the Australian Antarctic discordance, midway between Australia and Antarctica. The drilling will map out a boundary between geochemically distinct Indian Ocean mantle and Pacific Ocean mantle that appears to have migrated into the region as Australia has separated from Antarctica. The principal operation was seismic profiling using a gas injected (GI) airgun and six channel streamer. SEA BEAM, gravity and magnetics data were also collected. Although the seafloor age throughout the survey region is 20-30 million years old, it is remarkably free of sediment. Nevertheless we were able to identify enough small pockets of sediment in valleys, and occasionally perched on abyssal hills, to identify an array of potential drill sites.