>Ballard and his team discovered an underwater Yellowstone — a highly geologically active area of lava flows, fissures, vents and chimneys. Towering hydrothermal vents stood as the backdrop for a realm of life no one had ever encountered: towering tubeworms, massive clams, bearded mussels and ghostly white crabs. Peering out of Alvin's tiny portholes, the three-man team sat awestruck by the oasis of life they found flourishing — entirely without connection to the sun's energy.
>Until 1977, all food chains and all life were thought to rely on solar energy and photosynthesis. The deep ocean was assumed to be a wasteland where sparse populations of deep-sea creatures looked upward for a meal of meager particles that rained down from the sunny shallows. But deep in the dark ocean, Ballard and his team had discovered organisms that sustained themselves completely with chemicals from within the Earth's crust. The fact that organisms could harness the energy of chemical bonds, a process called chemosynthesis, dramatically increased the number of habitats capable of carrying life — on Earth and beyond.
>Weighing more than 6,000 pounds and roughly the size of a car, Hercules is loaded with sensors and sampling tools, dexterous manipulator arms and cameras aimed in eight directions. In a decade of exploration, Hercules and Argus have sampled and surveyed deep-sea corals, ancient shipwrecks, underwater volcanoes, seafloor trenches and war history in the Mediterranean, Black and Aegean seas, the Gulf of Mexico and throughout the Caribbean. The goal of the 2015 expedition to the Galápagos Rift is to better understand how hydrothermal vent systems age and change. The voyage also represents a special homecoming. As Ballard directed the team from the Nautilus control center, he laid his eyes on the site of his most important discovery for the first time in nearly four decades.
>In 2011 the Okeanos Explorer, a collaborating ship from the National Oceanic and Atmospheric Administration (NOAA), found a low-temperature diffuse vent field with nascent life present along the rift. NOAA named the site Tempus Fugit. In this year's mission, eager to determine how Tempus Fugit had matured in four years, Nautilus deployed its robots. Teams in the control center, collaborating scientists onshore, future explorers in classrooms and public audiences in museums nationwide sat glued to their screens as Hercules inched eastward along the Galápagos Rift.
>Scientists now support the hypothesis that Galápagos vent communities are overturned on decadal timescales rather than at the millennial pace of many geologic processes. Studying creatures that thrive in this alien world reveals special adaptations for the boom-and-bust unpredictability of living off vent fluids. Riftia worms have no digestive tract; that organ system atrophies after juveniles settle near a vent site to allow more body space for internal chemosynthetic bacteria that harness the hydrothermal buffet flowing past. Almost all organisms in this environment broadcast spawn their larvae into ocean currents, hedging their evolutionary bets that offspring will land near another flow if the parents' vent fizzles out.
>Future exploration of the seafloor will continue to unveil new answers and new questions about the flexibility of this environment and life itself. As pilots guided the robots (and a rapt global audience) through the deep-sea ecosystem, Ballard cheered for the beautiful communities and remarked, "They won't be here for long. All the wonderful vent sites we discovered in '77, '79 and 2001 have been completely destroyed by fresh lava. You're living on borrowed time when you're living at the boundary of creation."
>The expedition to the Galápagos Rift was one of 12 exploratory missions conducted by E/V Nautilus in 2015. Opportunities to sail aboard Nautilus are available for high school students, undergraduate and graduate interns, formal and informal educators and collaborating scientists. Learn more at oceanexplorationtrust.org.
>Join the Nautilus
>Anyone can join E/V Nautilus during missions via NautilusLive.org, 24 hours a day, 7 days a week.
>Check out this "Giant Black Smoker Hydrothermal Vent" the E/V Nautilus team discovered in the Galápagos Rift region.
>© Alert Diver — Q4 Fall 2015