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Thursday, April 19, 2007

Medusa's Deep Sea Vent


Art © Barry Smith; Medusa © Marvel Comics
A new "black smoker" -- an undersea mineral chimney emitting hot, iron-darkened water that attracts unusual marine life -- has been discovered at about 8,500 feet underwater by an expedition and dubbed the Medusa hydrothermal vent field.

The researchers picked that name to highlight the presence of a pink form of the jellyfish order Stauromedusae as well as numerous spiky tubeworm casings that festoon the vent chimney and bring to mind "the serpent-haired Medusa of Greek myth," said expedition leader Emily Klein.

"It's astonishing that a rich ecology thrives in these extreme environments," Klein added. She noted, however, that while all the organisms near vents are adapted to the high pressures at these depths, not all experience extremely high temperatures.

"The temperature of the ocean floor is about 2 C and there is a strong temperature gradient as you move away from the vent, so animals living a few inches away may experience temperatures only a few degrees above normal for the ocean floor."

"Despite the great tempeature of the vent water, it doesn't boil until 390 C because pressures on the ocean floor are so great, about 200 times the pressure at sea level," Klein said. The tremendous pressures result from the weight of almost two miles of seawater pressing down from above. link