Tuesday Afternoon: Finding a Lost City When You Can't Ask For Directions
|Enlarge ImageSitu Studios makes scale models of landscapes you'll never walk on, like this one of the TAG hydrothermal mound at the bottom of the North Atlantic. (photo by Hugh Powell, WHOI)
|Enlarge ImageHow the TAG model might appear on a flyby from a survey robot. (photo by Hugh Powell, WHOI)
Searches for Undersea Vents Bring New Finds
Twenty-eight years after the discovery that hydrothermal vents were
spewing superhot water and rare chemicals into the deep ocean, the
discoveries are still coming fast. A session on hydrothermal vents this
morning -- coincidentally held two-escalators deep under the Marriott
Hotel -- focused on new finds in the Arctic Ocean and detailed
descriptions of chemistry and sea life around Atlantic vents.
the self-motivated, Chris German even outlined how to go about finding
new vents. (Step one: acquire an undersea robot like the Autonomous Benthic Explorer [ABE].)
German’s team programmed ABE to traverse
a classic zig-zag search pattern (called "mowing the lawn") every 2 km
over an area they suspected harbored hydrothermal vents. Sensors on ABE
continually sniffed for characteristic temperature or chemistry signals
that a vent was near. After the initial broad search, the team refined
the search mission, and ABE slowly zeroed in on four new vent areas.
The onboard camera took pictures of the sites, revealing billowing
clouds of black smoke above rock pillars, with ghostly shrimp
swimming around the warm rock.
The search took about 30 days,
after which German’s team came ashore and handed over the new locations
to Karsten Haase of the University of Kiel, Germany, for a more
detailed reconnaissance. His instruments measured the chemistry and
temperature of the water and sampled shrimp and mussels to see how
similar they were to the creatures clinging to vents elsewhere in the
The teams named the new sites Red Lion, the Turtle Pits,
Wideawake Field, and Lilliput, following a tradition of giving
whimsical names to deep-ocean discoveries. Pumping out 396ºC water
(nearly four times as hot as water boiling on your kitchen stove), the
Red Lion vent was hot enough to singe the protective skin of ABE.
Deb Kelley of the University of Washington described the Lost City hydrothermal vents
and presented reasons why further searches might reveal that similar
vents, despite their otherworldly looks, are fairly common. After all,
along the giant ridges that divide the major ocean basins, seismic
thrashing is constantly bringing new rock and volcanic
material up to the seafloor.The session expanded on a press conference yesterday that described new finds in the TAG mound
(see sidebar for a description in 3-D), the first hydrothermal vent
discovered in the Atlantic Ocean 20 years ago. Details of how minerals
are deposited around hydrothermal vents, such as the TAG
site, have been described in Oceanus magazine.
|Hydrothermal Vents on Your Tabletop|
In case you’re having trouble imagining what a deep-sea “black smoker” vent looks like, now you can get an ABE’s-eye view from a fine-scale model designed by Situ Studios of New York. Architects at the firm started making scale models of landscapes after they realized their precision modeling equipment and software were perfect for the task. They had been using the equipment for jobs like modeling a skateboard park, designing their own furniture prototypes, and even making a sculpture of the SARS virus, said Situ partner Wes Rozen.
The team started by creating scale models of craters in India and on Kilauea Volcano, Hawaii, but they soon expanded into the ocean, modeling the TAG hydrothermal vent and the East Pacific Rise , and into space, reproducing part of a 20º arc along the Mars surface.
Rozen said the firm got into the work because “it gives us access to landforms we don’t have access to as architects but we’re excited by.” He wondered how the sites get explored in the first place, and whether there are submarines that can carry people down to the vents.
The answer, Wes, is yes there are, and you can even browse images from the dives yourself - read about it in yesterday’s post.