|
|
May 23, 2005 Dear Crew, Have you found any of the vents so far on the expedition? And are you having fun on the expedition? Katie Baseman and Ashley Lemmon Dear Katie and Ashley: I just came up from the dive to the Rosebud site—the new site we discovered in 2002. Back then, there were only juvenile animals (mussels and clams). Today, I saw how much everything has grown! Now there are tubeworms five feet (1.5 meters) tall and as big around as your arm. The mussels are also as big as a fist! It is very exciting being out here, and I think everyone is having fun, although working hard. Thanks for your e-mail—I hope you will follow along for the next 10 days on the Dive and Discover web site. Susan Humphris Dr. Humphris: I am excited to relay to my students the oddities of the various marine life at the vents, but I am geologically-handicapped. Can you explain how the rock formations at the vents may be different from what are found on land. Thanks! Dear Kathleen: If you have ever been to Hawaii, you have seen some rock formations that are quite similar to those at the bottom of the ocean—so you do see similar formations in certain places on land. However there are some different formations too! Imagine injecting hot, molten rock at 1,200°C (2,200 F) into cold seawater (close to 0°C or freezing). The surface of the rock quenches quickly and forms a shiny material called glass (it is called obsidian on land). However, rock is a good insulator, so the interior of the rock can stay molten and will continue to flow. Think of toothpaste oozing out of a tube and you have the picture. This process forms rounds rocks, called pillow lavas, as well as long tubes. At Rosebud, however, where there is a new flow the shiny lava forms a sheet flow that generally has a flat surface. Keep an eye out on the Dive and Discover Website for some pictures of lava along the Galapagos Rift. Good to hear from you! Best wishes,
|
|||||||||||||||||||
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
