Gulf of Alaska tracklines

Gulf of Alaska seafloor, showing June 2011 cruise tracks and ocean-bottom seismometer (OBS) locations. Data were collected along primary multichannel seismic (MCS) reflection lines (red) to measure sediment thickness in support of delimiting U.S. extended continental shelf according to the Convention on the Law of the Sea; OBS refraction lines (orange) were placed to establish speed of sound in sediment layers of the Baranof fan system; additional MCS reflection lines (purple) were run during extra time available at the end of the cruise. nm, nautical mile; EEZ, Exclusive Economic Zone (extends approximately 200 nm from shore or to a maritime boundary with another nation); 350 nm, the limit beyond which a nation's extended continental shelf may not extend; DSDP, Deep Sea Drilling Program; ODP, Ocean Drilling Program. Bathymetric data in northeast part of gulf were acquired in 2005 by USGS collaborators from the University of New Hampshire's Center for Coastal and Ocean Mapping/Joint Hydrographic Center.