This data set was acquired with the LDEO Multi-Channel Seismic system during R/V Marcus G. Langseth expedition MGL1110 conducted in 2011 (Chief Scientist: Dr. Donna Shillington). These data files are of UKOOA P1/90 format and include Seismic Navigation data that have not been processed. Data were acquired as part of the projects: Alaska/Aleutian megathrust and Megathrust seismic hazards by reflection mapping, and funding was provided by NSF grant: OCE09-26614.