Setting Sail

Tue, 22 Jul 2008 10:34 PM PDT

At 9 am under gray Seattle skies, the University of Washington’s Research Vessel Thomas G. Thompson set sail for the coast of Oregon to conduct the inaugural survey cruise of the NSF Ocean Observatories Initiative. On board are 32 scientists, engineers, marine technicians, and students from many different institutions and organizations: the University of Washington, the Woods Hole Oceanographic Institution, the Consortium for Ocean Leadership, the College of Charleston, Arizona State University, and the Geological Survey of Japan. They are microbiologists, geophysicists, marine geologists, chemists, and software engineers. The focus of the cruise is to launch a new approach to ocean sciences: selection of seafloor construction sites that will last 25 years.

There are also 21 ship’s crew members who live aboard the vessel and make it possible for the scientists to conduct their work. The ship’s crew pilot the vessel, keep the engines running smoothly, run the cranes used to lower scientific equipment over the side, and cook the superb meals that feed the ship and science crew.

Passing Seattle Landmarks

The cruise begins with passages under well-known Seattle landmarks of the University Bridge and the Ship Canal bridge. Then the bow swings west from its heading toward the Space Needle until Gasworks Park is off the starboard side. The Fremont Bridge is next, its distinctive blue and orange girdings drawing open as we wait to pass beneath. Next comes the opening of the Ballard Bridge and the transit through the Ballard Locks.

Waters are quiet during this passage from the fresh water of Portage Bay to the saltwater of Puget Sound. Many of the scientists take time to enjoy the scenery from the bow of the ship. Their work will come later. For now, especially the first timers in Seattle are soaking up the views and taking photographs. Others are setting up computers in lab workspaces, working on instruments on deck, making sure everything is securely tied down in preparation for the rougher water we know lies ahead as we transit for 18 hours to the open ocean.

Dunk Tests

Once in Puget Sound, the ship heads north, but not for long. Our first stop, or station, as they are called on a research cruise, is a “dunk test” of the new Sentry autonomous underwater vehicle.  This is the first formal deployment of Sentry on an oceanographic research cruise. Here in calm, sheltered waters is the best place to practice the launch and recovery. It is the first chance that the crew of the Thompson has had to work closely with the Sentry crew from Woods Hole, the first chance to communicate and coordinate on running cranes, handling tag lines, on the lifting, swinging out over the water, lowering and recovering of this unique piece of scientific equipment. It is worth over $1 million and is the pride and joy of the Woods Hole AUV group. An accidental collision against the side of the ship could be damaging, costly, time consuming, and inelegant. 

The practice run goes well as the Sentry team discovers a software problem that needs fixing. After a debrief with the Captain and Chief Scientists, and some discussion with fellow engineers, the launch and recovery process is modified, the software bug is fixed. By sunset, at another station farther north, the second dunk test is declared a success. We are ready to face the open ocean and  the winds and waves that are inevitable offshore.

The Schedule
Members of the scientific crew meet in the ship’s Library to hear Chief Scientists John Delaney and Deb Kelley lay out a schedule for the next 48 hours. Once we leave the Straits of Juan de Fuca, we will turn south and start mapping the edge of the continental shelf with the multibeam sonar EM300 system mounted on the hull of the Thompson. This mapping is an important part of the Ocean Observatories Initiative survey work. Operators of the major pieces of equipment we will use on this cruise brief the scientific crew on how their instruments operate. First operation scheduled for tomorrow is a deployment of the TowCam system, which takes photographs of the seafloor and will recover the first water samples of the cruise for the Arizona State University microbiologists.

The day ends as we round the “corner” of the Olympic Peninsula and head south toward the work area.

Contributed by Nancy Penrose, Science Support