The Research Vessel Roger Revelle (named for an eminent scientist and former director of the Scripps Institution of Oceanography) was built for scientific exploration.

This 274-foot ship, operated by Scripps, a graduate division of the University of California, San Diego, comes complete with technology, laboratory space and berths, so science team members can live and work aboard for weeks at a time.

The Revelle is the sister vessel of the R/V Atlantis, which is also in Alaska waters (in the Gulf of Alaska) this summer. For more on the R/V Revelle, including the captain's daily report, see the Scripps site at http://shipsked.ucsd.edu/ships/revelle/index.html.

JASON II/Medea

Jason II/Medea is a remotely operated, unmanned submersible system that was made to explore the deep ocean and seafloor while still tethered, or connected to the ship by cable. Often called just Jason II for short, the ROV system can reach depths of 6,500 meters (more than 4 miles) and can log far longer work days then vehicles with people on board.

Operated by technicians on the ship, the Jason II is highly maneuverable and can capture video and take samples from the ocean floor while controllers and researchers stay dry. This expedition is the farthest north exploration to date for Jason II, which was designed by the Woods Hole Oceanographic Institution's Deep Submergence Laboratory.

For more information on Jason II/Medea, see http://www.whoi.edu/marops/vehicles/jason/spec_jason.html.

Multibeam Sonar

In the year before this cruise, researchers used a sonar system mounted on the hull, or bottom, of a research vessel to create the most highly detailed maps in existence of portions of the Aleutian region seafloor. These maps are helping guide the 2004 explorations.

Multibeam sonar uses a loudspeaker mounted on the bottom of the ship to bounce sound waves off of the ocean floor. A microphone picks up the echoes of returning pulses of sound and translates the information into distances that can be plotted on a high-resolution map.

Canyons, mountains and other features exist underwater, just as on land. In 2003, while conducting similar mapping for related coral research, the science team made detailed observations of a previously unknown undersea Alaska volcano.