|
|
May 28, 2002 Hello, Thank you once again for taking us on an outstanding adventure. My fifth grade students are studying habitat communities of the Arctic, Tropical, Temperate Oceans, and the Kelp Forrest and Hydrothermal Vent. Our question is, “Does a vent ever close or cease to function?” Thank you. Hi Ms. Lewis, The answer is “Yes, indeed.” Vent sites only exist because of the heat from hot magma rising near the seafloor. The heat launches chemical reactions between seawater and seafloor rocks that create chemicals that support microbes. The larger animals at the vent sites, like clams and tubeworms, host microbes in their bodies and gills. These microbes convert chemicals in vent fluids into food for the tubeworms and clams. So if the heat ceases, the fuel for the entire communities “dries up,” and the vent sites turn into the underwater equivalents of ghost towns. Another possibility is that a new lava eruption from the seafloor can wipe out a vent community. Or a new lava can rise out of seafloor fissures, flow out over the seafloor and “pave over” vent sites. Right now, we think that might have happened to “Rose Garden.” We’re very glad you are following along. Thanks for your question. Best regards, Dear Tim Shank, I’m a seventh grade student of Miss Sheild in Lexington, MA. I was really interested reading about the search for the Rose Garden. Were you worried or anxious about finding the Rose Garden? Even though you found the new vent site, was it disappointing that you didn't find Rose Garden? It must be suspensful and exciting to look for the Rose Garden. Good luck finding it! Sophie Del Donno Hi Sophie: I must say that I would be very disappointed if we didn’t find “Rose Garden.” One of our main goals has been to learn how communities of life around vents change—how larvae of animals settle in at a site, how fast they grow and spread, how other animals come in later, how they interact with the original animals and perhaps take over a site. It’s relatively easy to observe a park, for example, and see how it changes and how the animals in it change. But undersea, it's hard to watch a spot continuously. It’s just too difficult and expensive to return to the same place every year. That’s why Rose Garden is so special. Scientist have come back here four times since 1979, so we could track changes over time. We know what has happened there from 1979 to 1990. It was my dream to keep that going—to see what has happened since 1990 and add that to Rose Garden’s history. Yes, it is suspenseful. I wish we had found Rose Garden on our first dive. But maybe it is no longer there to find. Thank you very much for looking into Dive & Discover. This is David Perelman from Ms. Shield’s class at Jonas Clarke Middle School in Lexington, Massachusetts. What types of animals have already been discovered around the Galápagos Rift? Also, what types of vegetation and animals are you going to be looking for? Hi David, Since hydrothermal vents were discovered in 1977, about 500 completely new species have been found at vents around the world. Giant clams, mussels, several types of tubeworms and other types of worms, snails, anemones, shrimp, crabs, octopi, and slithery, eel-like fish. There are also jelly-like orange animals called siphonophores (they are cousins of Portuguese Man O' Wars). It is really a colony of animals that moves together. And then there are all the amazing microbes that used chemicals dissolved in hydrothermal fluids to grow and get energy to live. Some are bacteria, but some are Archaea, which are also single-celled, but are a completely separate kingdom on the tree of life. You might look at “Vent Biology” on the Dive & Discover Web site, or “The 25th Anniversary of Hydrothermal Vents” site for lots more information (look under the “Major Discoveries” section, “A changed view life.”) As for vegetation, there is none. There is no sunlight on the seafloor, so there are no plants. Plants use sunlight in photosynthesis to grow and get energy. On the deep seafloor, plants would be dead ducks. As we explore, we are always looking for any new animals we might see. And we are looking to see how all the different animals interact with each other. We want to know what lives where and why, who eats whom and when—questions like that. Thanks for your question. Dear Deep Sea Explorers - I read with interest your difficulties with finding the rose garden. Could you talk about why GPS can’t be used in this case? (I assume it can’t) What type of mapping has been done of the sea floor in your area? Is there another project scheduled to do that? Thanks for the Information. Interested Science Teacher Hi Interested Science Teacher, We do use Global Positioning Satellites (GPS) for positioning the RV Atlantis on the surface. And then Atlantis uses acoustic pulses to locate the positions of the surveying transponders on the seafloor. Because electromagnetic waves cannot penetrate water, we can’t use the satellite directly to find locations on the seafloor. Check out the Oceanographic Instrumentation section of Dive & Discover to find more information about navigation. We are making extremely detailed maps of the seafloor with ABE. They represent the best current knowledge of the bathymetry for this part of the Galápagos Rift—down to about 1 meter vertical resolution. We will be combining the ABE bathymetry with visual observations of the seafloor from Alvin and from our towed camera system to make a geological map of the area. We will correlate that map with observations of where the animal communities are distributed—so we can make connections between what’s living on which parts of the seafloor. We hope to have these maps and data serve as the basis for continuing studies in the Galápagos Rift in years to come. Thanks for your question and for Diving and Discovering with us. Best Regards,
| ||||||||||||||
Mailing List | Feedback | Glossary | For Teachers | About Us | Contact
© 2010 Dive and Discover™. Dive and Discover™ is a registered trademark of
Woods
Hole Oceanographic Institution
