Alvin, the little manned submarine that could, is still plugging away at the frontiers of ocean exploration half a century after it was first launched.
Woods Hole Oceanographic Institution, which operates the Navy-owned sub, celebrated Alvin's 50th birthday on Thursday. Scientists count somewhere near 4,900 dives made by the three-man sub — and 2,600 researchers who have used it — to explore different parts of the ocean.
But Alvin was not available on Cape Cod for the occasion. Larry Madin, director of research at Woods Hole, said Alvin is in Gulfport, Miss. and would spend the day much the way it has spent every day of the past 50 years: working.
Deep-sea exploration is a risky business.
Last month, the futuristic deep-sea diving underwater robot Nereus imploded some 6 miles underwater in the Pacific Ocean. In 2010, another submersible explorer, ABE, was also lost.
The number of such submarines, however, is growing, and Woods Hole has a large fleet of underwater explorers, many of which are less well known.
Alvin has been a workhorse with unusual longevity. But keeping a submarine in good working order requires constant maintenance, upgrades, and replacement of parts.
The sub — about the length of a killer whale — has seen a lot in its half-century roving the sea; it probed the wreckage of the Titanic and located an unexploded hydrogen bomb at the bottom of the Mediterranean Sea.
But for Madin, its signal achievement is one that transformed scientific understanding of life in the deep ocean and in extreme environments : the discovery of hydrothermal vents that support an unexpected ecosystem.
Alvin was probing a mysterious source of warm water in the late 1970s when the vents were discovered, Madin said.
The scientists on board were geologists, interested in rock formations and water chemistry. They had detected some kind of influx of heat coming from the ocean floor, but did not know the source. When they found the source — underwater formations that spew hot water into the ocean similar to a geyser on land — they did not expect to find any life. Yet, that is what Alvin ultimately revealed: an ecosystem that supported tubeworms, giant clams, shrimp, and mussels.
Woods Hole has set up a website where people can submit video birthday wishes and remembrances of Alvin.