| Daily Updates: May 2002
| Daily Updates: June 2002
Latitude: 0 deg 48.3'N
Longitude: 86 deg 13.9W
Wind Direction: S x E
Wind Speed: 12 Knots
Sea State 2
Swell(s) Height: 4-6 Foot
Sea Temperature: 82.1°F (27.8°C)
Barometric Pressure: 1013.2 MB
Visibility: 12 Nautical Miles
Carrot Cake Muffins
Grilled Bratwurst with Bun
Baked Linguini and Crab
Turkey Noodle Casserole
Snickers and Ice Cream Bars
Mashed Potatoes and Gravy
Cauliflower with Garlic Paprika Sauce
Have they paved paradise?
May 27, 2002
by Lonny Lippsett
As the sun began to set in the Pacific Ocean, scientists, students,
technicians, and crew gathered on RV Atlantis stern.
They were eager just as you areto hear whether Tim
Shank and Dan Fornari, diving today in Alvin, had found
the vent site known as Rose Garden.
Timemerged from Alvins sail, climbed down the ladder,
strode across the stern, and approached the small crowd.
As far as we can tell, he said. Rose Garden may be no more.
Alvin landed today near what scientists
call the axial high. It
is a raised strip of seafloor that runs down the middle of the Galápagos
Rift Valley. It is raised because thats where lava erupts at the
seafloor and piles up and flows outward. Hydrothermal vent sites are
often found on axial highs. Rose Garden was located on the southern side
of the axial high.
Tim, Dan and Alvin Pilot Phil Forte found
a central fissurea crack
in the seafloor that lava has spewed out of. They followed that fissure, first
to the east, where they found shells of clams that Tim estimated had died 50
to 150 years ago. Any venting there had faded long ago.
Then they tracked the fissure westward, all along
the axial high, all the way to the vent site Tim and Steve found
yesterday with very small, very young mussels, clams, and tubeworms.
They found the site late in their dive and did not have enough
battery power left to look around and sample. They had marked the
spot with a plastic bucket lid tied to a weight and marked with
the letter A.
Today, they looked all around the site. They
found that the young vent site lay atop another lava flowlike one hand atop another. The upper flow had the
young animals. The lower flow had clumps of mature mussels and fully grown tubeworms.
They sampled the lava.
The lava is quite fresh, Dan said. The lava flow is very young.
We think the young community of animals has started to develop on lava
that may have paved over older communities underneath it, Tim said. One
of those paved-over communities might have been Rose Garden. Rose Garden
may be a parking lot, he said.
For biologists, Rose Garden is a unique, underwater
paradise. First found in 1979, it was lush with life, and scientists
revisited the site in 1985, 1988, and 1990. They studied the site
extensively to see how vent communities change and how different
animals move in and interact with each other. When they visited,
they left dozens of plastic markers at the site. During perhaps
a dozen dives to Rose Garden over the years, Alvin had also
left behind more than 40 steel plates on the seafloor
near Rose Gardenthe steel plates that it uses
to descend and that it drops to surface again. Today, Tim, Dan, and Phil saw
no plastic markers and no weights. Were these, too, paved over by a fresh lava
flow that occurred sometime after the last visit in 1990?
Perhaps. But perhaps not. I find it difficult
to believe that all signs of human activity could have been obliterated, said
Susan Humphris, who will dive tomorrow for another look. Perhaps
Rose Garden is tucked away in a spot that Alvin has not
yet crossed in the past two days.
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