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	Like many expeditions involving WHOI scientists and engineers, the cruises to the Lau Basin require a multidisciplinary team. Participants on the September 2004 cruise included engineers Dana Yoerger (1), Rod Catanach (2), Al Bradley (3), and Joint Program engineering student Mike Jakuba (4), as well as geologist Dan Fornari (5) and biologist Tim Shank (6). Geochemists Meg Tivey (7) (who will be the Chief Scientist) and Jeff Seewald (8) will participate on the April 2005 return to Lau Basin, which will involve deep-sea exploration with the remotely operated vehicle Jason. (Photo by Tom Kleindinst, WHOI Graphics Services)
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	Vent spires rising 10 meters (33 feet) above the seafloor were found along fissures.

Like deep-sea treasure hunters, the oceanographers and engineers began their search with a rough map and a few clues. They sought neither silver nor gold, but hydrothermal vents in the Lau Basin, a previously unexplored area in the southwest Pacific Ocean.

“We knew there were vents, but we had to figure out exactly where,” said Dana Yoerger, one of six WHOI researchers who worked from the research vessel Kilo Moana in September 2004. “Our clues appeared in the form of smoke,” he said of the buoyant plumes of warm, chemical-rich fluids that rise from deep-sea vents and spread a few hundred meters above the seafloor.

The vents offer a potential treasure trove of information about how Earth works, and how deep-sea vent organisms have adapted to thrive in these sunless places, under extreme pressure and intense heat. The processes that shape the Lau Basin are undergoing study through a series of cruises that are part of the Ridge 2000 Program.

High-resolution seafloor and plume maps made by a University of Hawaii group were used to guide surveys by WHOI’s Autonomous Benthic Explorer (ABE). ABE, a free-swimming robot used to locate the vents, flew 10 to 300 meters (33 to 990 feet) above the seafloor on a series of missions at six sites. The robot searched for telltale changes in water temperature and chemistry that signaled the presence of a vent.

In the image shown, at the ABE vent site, the vent spires were about 10 meters (33 feet) tall and located along fissures that crack the volcanic seafloor, allowing hydrothermal fluids to exit. ABE enabled researchers to make detailed bathymetry maps of the site and also collected digital images to document organisms living at the vents.

The cruise was funded by the National Science Foundation Ridge 2000 Program; four WHOI scientists were supported by the Deep Ocean Exploration Institute.