Crone thought sound, if detected, could be a way around the problem.
So he and his colleagues plunged deep-sea recording equipment 1.4 miles (2,200 meters) down into a vent field 300 miles (480 kilometers) west of Seattle.
The team recorded 45 hours of sound at a vent called Sully and 136 hours at a vent called Puffer.
"This confirms what was in my gut early on," Crone said.
The researchers suggest the low rumbling sounds mostly result from the flow within the vent structures themselves.
Crone likened the sound to that made by spraying a garden hose against the wall of a house.
In addition, rumbles may be generated as the hot fluid mixes with the frigid sea water and contracts, Crone said.
The rumbles got louder and quieter as the tides went in and out, Crone noted, a phenomenon predicted by numerical models. The changes in volume are thought to be related to changes in flow rate.
"We may have already seen we can measure flow rate change with these types of techniques," he said. "But a lot more work has to be done to be certain of that."
When the sounds were analyzed by computer, the researchers also detected resonant tones perhaps generated as the fluid moved over cavities and bumps inside the vent.
"That would also give each vent [its] own particular sound," Crone said. "For me it's hard to tell the difference between them, but if you live down there you might be able to tell one vent from another."
Crone and his colleagues speculate that fish and other sea creatures use these sounds to navigate the deep, dark sea.
"The 'light' of the deep sea is sound, and if something down there is making noise, you can be certain that organisms that can hear are using that piece of information," Crone said.
"It's too good to not pay attention to."
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