We never promised you a Rose Garden
May 26, 2002
by Lonny Lippsett

Co-Chief Scientist Tim Shank emerged from Alvin late in the evening, put on his shoes, walked down the gangplank, shrugged his shoulders, and sighed. “It was a lo-o-o-ong Sunday drive,” he said.

Alvin set out at 8 a.m. Sunday, seeking to return after 12 years to the hydrothermal vent site known as “Rose Garden.”

“Until today, we thought we knew where Rose Garden was,” said Co-Chief Scientist Steve Hammond, who joined Shank and Pilot Pat Hickey in the submersible. “A location for Rose Garden has been published in many scientific papers. Today, we found a lot of places where Rose Garden wasn’t.”

Alvin submerged over the “X” that marked the spot where Rose Garden was reported to be. That “X” is approximate because it’s difficult to pinpoint an exact position on the seafloor. The crew searched over an area of roughly 1 km by 1 km, traveling a total of 6 km. But they could not find Rose Garden.

It was a humbling reminder of the difficulties of exploring the seafloor. Imagine parachuting into a desert, in complete darkness, and trying to locate a particular sand dune with only a flashlight. There are few landmarks to guide you—just sand in all directions. Even when you run into a distinguishing feature—like a hill or a valley—it’s difficult to figure out how that feature fits in with the rest of the landscape that you can’t see.

On the seafloor, Shank, Hammond, and Hickey watched through Alvin’s viewports as they passed over great folded fields of lava. But no vent life.

Rose Garden is believed to be on top of a small ridge in the center of the 2-km-wide valley of the Galápagos Rift. Scientists call the ridge the “axial high.” When Alvin reached the south wall of the valley, the crew knew it had gone too far, and Hickey turned the sub around to steer toward the center of the rift valley.

“Sometimes you just get lucky,” Tim said. “Sometimes you try as hard as you can, and nothing happens.” It looked like today would be one of those days. “We hadn’t given up yet, but we were pretty disheartened,” Tim said.

But, then, the scientists saw that axial high. And on it, was an area where a few cracks, about 10 meters long, stretched along the seafloor. A few fish swam by—a good sign. Shimmering, warm water wafted out of the cracks. The seafloor was suddenly carpeted in anemones. And nestled in the cracks were tiny mussels and clams, some as small as 2 centimeters (1 inch). With them were small tubeworms, Riftia pachyptila, which can grow up to eight feet tall. The longest ones here were only 2 feet and some were as small as 2 centimeters.

“They could be very young—a few months old,” Tim said, “and I’ve never seen only young clams, mussels, and tubeworms—without any adults—all together in the same place. In 10 years of research, I’ve never seen a community structure like it.”

By that time, Alvin’s batteries were low and it had to surface. The crew left a marker on the seafloor at the spot, and Alvin will return tomorrow to explore this brand new vent site. Then it will continue the search for Rose Garden, which should also be on the axial high. In fact, the scientists now think it is only 350 meters farther east.

“We got very close,” Hammond said. “We should find it tomorrow. Unless it’s been covered over since 1990 by new lava.”

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