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April 1, 2001 Dear Dr. Humphris: The expeditions in the Pacific Ocean have found chemosynthetic tube worms that differ greatly in size. Have tube worms been found on the Mid-Atlantic Ridge? Do the scientists hypothesize that the biology in the Indian Ocean will be more like that found in the Atlantic or Pacific? Kathleen Heidenreich’s class Hello Ms. Heidenrich’s class: Tube worms do exist on both sides of the Pacific Ocean. It has been hypothesized that the Indian Ocean ridge system may be a pathway for migration of animals between Mid-Atlantic and western Pacific vents. Our only knowledge of vent animals in the Indian Ocean has been obtained in the past few years. A single barnacle was dredged from the Southeastern Indian Ridge. This barnacle closely resembles those we know well from vents in the western Pacific Ocean However, a few months ago, a small vent site on the Central Indian Ridge was discovered that has swarms of shrimp and mussels - like vents in the Atlantic! So there is a little evidence for both Atlantic and Pacific fauna in the Indian Ocean. Follow our exploration of the Indian Ocean during the next month and discover with us what kinds or organisms we find, and whether they are more like those at Atlantic or Pacific vents. Tim Shank Hi! I’m Kristin from EPCHS in East Peoria, IL. How much education do you need to be a part of the crew? Has anyone left the ship to go home? Please respond as soon as possible. Hi Kristin: Both deck and engine room (ER) crew follow parallel tracks, so I will talk about them together. To become an Ordinary Seaman (OS) or a Wiper, which are the entry level positions for deck and ER, you have to be 18 years old and go to the Coast Guard station and get what is known as a “Z” card. There are no special educational requirements. To advance, you then have to sail in these positions for about a year, after which you take a test to become either an Able-Bodied (AB) Seaman (deck) or an Oiler (ER). For the ER, there is another test to become a QMED -- Qualified Member of the Engineering Department. There are two ways to become either a Mate (deck) or an Asst. Engineer (ER): one is to work your way up through gaining experience and taking exams. To become a 3rd Mate, an AB has to sail for 1000 days, and then take a test. To become a 3rd Ass. Engineer, an Oiler has to sail for 1 year and then take a test. The second way to become a Mate or an Asst. Engineer is to go to a Maritime Academy for a four-year college program. At the end, you have a B.S. in a relevant subject (e.g. Marine Transportation and Operations for deck; Mechanical Engineering for ER) as well as a license to sail as a 3rd Mate or 3rd Asst. Engineer. There are different types of Captain’s (or Master’s) and Chief Engineer’s licenses depending on the size and tonnage of the ships you sail, the geographic areas you sail (for Masters), and also the horse power of the engines (for Engineers). For a ship like Knorr, you could sail for 1 yr as 3rd Mate or Engineer and then take an exam to become a 2nd Mate or Engineer; sail for 1 yr as 2nd and then take an exam to become Chief Mate or First Asst. Engineer; and then sail for another year and then take an exam to obtain a Master’s or Chief Engineer’s license. In response to your other question, no-one has left the ship to go home as we are in the middle of the ocean! Right now, we are hundreds of miles from land, out of range of even helicopters, so it is not possible for someone to leave. If there was a medical emergency on board that required a land-based hospital, we would have to steam back to the nearest port, which would take 2-3 days. Hope this answers your questions -- and hope you will stay tuned for new discoveries and adventures. Susan Humphris How many research ships have gone to the Indian Ocean before? Philip’s questions Hello Philip: Thanks for the questions -- they are very good! Here are some answers: • How many research ships have gone to the Indian Ocean before? I cannot give you an exact number, but research ships from the US, the United Kingdom, France, Germany, Japan and India are some of the ones that I know. Although that sounds like a lot, it is not often that a research ship makes it all the way here as it is such a long way from most of the places I named. • How deep is the Jason going? On this cruise, we are searching for hydrothermal vents so we don’t yet know how deep Jason will go. However, it is likely to be between 2000 and 4000 m (which is between 2 and 3 miles). Compare that to the distance from your house to school. • How wide is the Jason? Jason is about 4 feet wide. • What sea animals do you think you will be seeing? Around the hydrothermal vents, we expect to see shrimp, anemones, mussels, crabs and possibly other animals. We don’t really know what else -- that is one of the reasons we are out here doing research. We also hope to see some whales and dolphins, and perhaps some big fish swimming around the ship. • How deep is the area where the Knorr is going? Well, it is the same depth as Jason will be diving since Jason will be going to the seafloor. However, on our way here, we went over some areas of the ocean where the water was deeper than 4000 m. • How wide is the biggest room on the Knorr? (Which room is the biggest?) If you include all the auxiliary machine rooms that are part of the Engine Room, then that would be the biggest compartment on the ship. Unfortunately, it is a difficult space to measure. However, we measured the next biggest space for you, which is the Main Lab. It is 26 feet wide and 61 feet long. Keep Diving and Discovering! Gentlemen / Ladies: I am truly fascinated by your Internet tour of the deep seas and this expedition. I am an Instructor in Fiber Optics and related advanced Electronics and am curious as to the use and problems that might occur in the dives of this type and the use of fiber optics. Additionally, since light is used to photograph objects at the abyssal depths, what effect, if any, does this light have on the tubeworms, fish, crabs, etc. ? Is the light delivered via Fiber optics or in the more traditional quartz flood lamps ? Thank you for your time, I remain “glued to the monitor” and appreciate the armchair tour !! Van Ewert Dear Van: With regard to the use of fiber optics -- Generally, the use of fiber optic cables, connectors and other components has been quite successful. Of course, careful design and testing is required to ensure reliable performance. The fiber optic cable used with Jason for example took several years of development and testing before it could be considered reliable enough for this type of work. Likewise, fiber optic connectors and high pressure penetrators have required careful selection and testing. In the deep-sea environment, where ambient pressures are high, phenomena such as micro bending become significant issues. In terms of lights, we use metal halide lights on Jason for the video and still imagery. With regard to your question about the effects of lights on the organisms -- We do not know much about this for many of the hydrothermal vent organisms, but a little is known about the shrimp that are common at vents in the Atlantic. The lights do not appear to alter their behavior. However, there is some evidence that the lights alter the structure of the photoreceptor in such a way that it may not be able to produce rhodopsin any more. However, since we have not determined the visual capacity of the shrimp, we do not know the effect of this. Stay tuned as Jason goes to the bottom of the Indian Ocean tomorrow. Susan Humphris |
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