Okeanos Explorer (EX2303): Seascape Alaska 2: Aleutians Deepwater Mapping

Vessel: NOAA Ship Okeanos Explorer; Expedition Dates: June 6 - June 20, 2023

Project Principals: Thomas Morrow, NOAA/OAR/OER (Expedition Coordinator and Mapping Lead)

From June 5-20, 2023 (Dutch Harbor, Alaska to Kodiak, Alaska), NOAA Ocean Exploration conducted mapping operations off the coast of the Aleutian Islands in U.S. waters, aiding in closing bathymetric gaps within this region. Expedition EX2303 collected 37,601 square kilometers of bathymetry and associated water column within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. During mapping operations, NOAA Ocean Exploration simultaneously collected EM 304 multibeam sonar bathymetry observations and Simrad EK60/EK80 split-beam fisheries sonar observations of biologic material in the water column, as well as Knudsen 3260 sub-bottom profiler observations of sub-seafloor geologic structure and sediment. A focused survey region targeted potential geological hazards along the Aleutian Trench. During the expedition, one CTD cast collected water samples for environmental DNA (eDNA) analysis. The exploratory mapping operations conducted during this cruise will provide initial characterization of the region, as well as data to support further exploration.