Unmanned marine robots, called autonomous underwater vehicles,
can be used for myriad research purposes. The type the Woods
Hole Oceanographic Institution in Massachusetts employs goes
to the Arctic's icy depths.
deployed two AUVs, Puma and Jaguar, in the summer of 2007 to investigate
hydrothermal vents along the seafloor in an area of the eastern
Arctic Ocean called the Gakkel Ridge.
The ultra-slow-moving plates of the Earth's crust in that region
produce volcanic activity and unusual interactions between the
hot gases and the nearly freezing ocean water. Scientists have
been eager to look at the zone's creatures, which they believe
have evolved in isolation over millions of years.
During WHOI's 40-day mission to explore the mid-ocean ridge's
handiwork, Puma "sniffed out" chemical and temperature
signatures of the mineral-spewing vents, and Jaguar took pictures
and used sonar to map the ocean floor. A tethered, remote-controlled
vehicle scooped up rock samples, sediment and creatures for scientists
Researchers aboard the Swedish icebreaker Oden dropped the AUVs
through holes in the ice and retrieved them through other holes
-- that is, unless the icepack was so compressed that the drifting
sheets created no openings. In one such situation, recalled mission
chief scientist Robert Reves-Sohn, the Oden had to "wiggle"
around in the ice, creating just enough room around the hull to
allow the AUVs to surface. "It was a very challenging activity,"
WHOI's two polar AUVs were custom-made to essentially act as
helicopters to travel to depths of 4,000 meters -- much deeper
than their torpedo-like counterparts, Reves-Sohn said. Besides
learning more about this isolated spot on Earth, the mission was
aimed at testing autonomous exploration and sample-return techniques
that NASA will use in its search for life in the ice-covered oceans
of Jupiter's moon Europa.