Seascape Alaska 6: Gulf of Alaska Transit Mapping

From September 23 to October 14, NOAA Ocean Exploration conducted the final expedition in the Seascape Alaska series on NOAA Ship Okeanos Explorer, mapping nearly 48,000 square kilometers (18,530 square miles) of seafloor along the West Coast while transiting from Alaska to California.

During mapping operations, NOAA Ocean Exploration collected multibeam sonar bathymetry, made observations of biologic material in the water column using a split-beam fisheries sonar, and made sub-bottom profiler observations of sub-seafloor geologic structure and sediment.

The team mapped a total of 47,899 square kilometers (18,494 square miles) of seafloor, covering a distance of 3,216 kilometers (1,998 miles). Highlights included mapping a portion of the Surveyor Channel in the Gulf of Alaska, discovering a chain of six mounds off the coast of British Columbia that were not visible in existing satellite altimetry data, completing a focused survey in the Cascadia Margin off the coast of Washington that improved data quality in a region of interest for geological hazards, and mapping five mounds off the coast of California that were previously only resolved through low-resolution satellite altimetry.

In the spirit and mission of outreach and education, the team hosted three explorers-in-training during the expedition and held a live interaction through the NOAA Live! Alaska webinar series that reached nearly 700 people, more than 600 of whom were students.