******************************************************** WATER & ICE EXPLORATION ******************************************************** *************************** EXPLORING UNDER THE ICE *************************** __________ QUESTION: What methods do scientists use to find out what is under the ice which covers the continent? ANSWER from Wilber King on Dec. 29, 1994: I provide technical and administrative support for the team of scientists and engineers currently in Antarctica. Your question asked what methods the scientists use to find out what is under the ice that covers the continent. Specifically, you were interested in active volcanoes. The scientists and I work for a department called SOAR which stands for Support Office for Aerogeophysical Research. To see what's under the ice we use four different devices: 1. radar, 2. laser, 3. gravity meters, and 4. magnetics. Here is a brief description of what each of those items can do. RADAR: is used to measure ice thickness. We attach the radar system to an airplane and fly all over western Antarctica measuring the ice thickness. The ice thickness in western Antarctica is over 2,000 meters. LASER: is used to make a map of the surface of the ice. So if there are active volcanoes under the ice they will cause the ice to melt above it which leaves a depression on the surface of the ice. The depression might look like a "pothole" on a city street, just thousands of times larger. GRAVITY: gravity meters are used in the airplane to make sure the airplane doesn't shift up and down during its flight. The straighter the airplane flies, the better picture it can take of the surface of Antarctica. MAGNETICS: are used in the airplane which we fly over Antarctica to find volcanic rocks as well as other rock formations. The magnetic system hangs from a long rope under the airplane as it flies over the ice. __________ QUESTION: How many things (once living) have you found in ice? ANSWER: On February 2, 1995, Diane Stoecker answered: We've found many different living things in the ice, but they are all one-celled. We've found bacteria, algae (at least 10 species) and protozoa. They live in little pockets of very salty water (brine) in the sea-ice. Associated with the bottom side of the sea-ice there are also zooplankton and small fish. We also see dead cells in the ice; these usually are organisms that live in the plankton. They got trapped in the ice as it was forming and weren't adapted to the cold and salty conditions in the sea-ice and thus died there. __________ QUESTION: Do scientists go into the icy waters of Antarctica? ANSWER from Katy McNitt, LTJG, NOAA, S-257 Monitoring Climatic Change, Amundsen-Scott South Pole Station, on January 7, 1995: Yes! Scientists DO go into the icy waters of Antarctica! I've never done it, but I have been scuba diving in relatively cold water and it's very strange! The people who dive off the coast of Antarctica will probably tell you that it's very painful, too. Have you ever reached into the bottom of a cooler at a picnic (because the best sodas are always at the bottom) and realized that your arm was starting to hurt? But you couldn't quite reach that One Can that you wanted, so you kept pushing your arm past the ice cubes and water until you had that can in your grasp, only to realize that your arm had gone numb, and you couldn't grab the can anyway? Not that I've ever done this ;-) but it only takes a minute or two. Now, imagine jumping into that cooler and swimming around for several minutes to an hour! Yikes! People who dive in cold water have to wear special diving suits to stay warm and dry. How do you suppose they keep the water out of these suits? The suits don't cover the divers' faces or hands, which become numb very quickly in such cold water. Face masks and mittens don't help much when the water is below freezing! With a numb face it's hard to breathe through a regulator, and with numb hands it's hard to do everything else! Can you think of other problems Antarctic divers might face? And: how can water be "below freezing" and still be water? *************** SCUBA DIVERS *************** __________ QUESTION: How do you video the penguins under water? ANSWER from M. Castellini on 1/13/95 These videos are taken either by divers carrying underwater cameras or by going down in an observation chamber that is dry and can be lowered from the surface. I am not a diver, but I have watched penguins from such a dry chamber. Very cold and dark, but very special to watch the birds from underwater! __________ QUESTION: Do scuba divers ever explore the sea near Antarctica? ANSWER from Jeff Merrell on January 23, 1995: Even though the waters surrounding Antarctica are extremely cold (- 1.9 degrees Celsius), divers have been exploring them for about 30 years. Routinely, divers are used for collecting organisms that live under the ice, such as starfish and other bottom-dwelling creatures, that cannot be easily collected in other ways. In most parts of the world, divers wear a wetsuit that allows the water to touch the skin; however, in the Antarctic the divers wear dry-suits with several layers of protective clothing underneath to protect them from the cold temperatures. Because of the cold temperatures, most dives in the Antarctic only last about 1/2 hour. People that are lucky enough to dive in Antarctica have the opportunity to see penguins, seals, etc., under the ice. ANSWER from Diane Stoecker on January 31, 1995 Yes, people do dive through the ice to study life on the underside of the ice, in the water under the ice and, in shallow places, life on the bottom. They have to wear big, bulky dry suits. Only their faces get wet, but still they can only make short dives because it is so cold. Our group didn't do any diving, but divers collected some samples of sediments for us so we could look for resting stages of ice algae in the mud. The animal life on the bottom in McMurdo is quite spectacular, big sponges, scallops, sea urchins and brittle stars. Some of the researchers studying penguins dive so that they can watch the penguins feeding underwater. __________ QUESTION: What do you wear when you go diving in the ice water? ANSWER from Deane Rink, Live From Antarctica field producer, on Wednesday, December 14: I'm not a diver, but I have had the privilege of filming three Antarctic divers from topside and have watched how carefully they prepare for diving under the annual sea ice down here in Antarctica. You're probably familiar with the normal wet suits that most mid-latitude divers wear. Well, down here, the divers prefer to wear what is known as a dry suit, a large body glove that incorporates a layer of air between the inner body lining and the outer, water-resistant polypropylene. Dry suits are much warmer and allow divers to work in the 28 degree Fahrenheit salty water that resides in McMurdo Sound. Divers always work in pairs, with one standing by at the surface in full diving gear ready to dive in case of some emergency. There is also a communications line through radio band that is set up between diver and tender (the safety diver topside); the radio band travels in a line enclosed inside the tether that the diver has attached to his/her body. Until the phytoplankton (microscopic marine plant life) bloom around this time of year, visibility in the waters of McMurdo Sound will generally run around 600 feet, much more than in normal tropical waters. The movies that these divers bring back from their dives, shot on regular Hi-8 cameras contained within special watertight housings, show an abundance of undersea life, most of which is very colorful. Starfish and sea spiders dominate on the bottom, with fish, seals, and penguins among the denizens of the actual water column itself. We hope to be able to show you some of the underwater life in one of our future Live From Antarctica programs. ANSWER from Dale Andersen on December 19, 1994: While diving in the cold Antarctic waters we wear protective suits made of neoprene, vulcanized rubber or coated nylon. These suits are waterproof, having seals at the cuffs and neck. Since water cannot get into the suit, we wear warm clothing underneath. Special diving mitts keep our hands warm and we must wear a neoprene hood on our heads. So "dry suits" are the best way to keep warm while diving underwater here. The water temperature in the ocean here is about -2 degrees centigrade (~28F) but in the lakes I dive in it is just a bit warmer--0 degrees centigrade (32F). Most of our dives last 45 minutes or so. ********************** UNEXPLORED PLACES ********************** __________ QUESTION: Are there unexplored places in Antarctica? ANSWER from LT "T" Stevens, U.S. Navy, on February 13, 1995: I'm sure there are many places in Antarctica where man has not stepped foot on, but about 95% of Antarctica is covered in ice. The parts covered in ice are studied for depth and age of ice, etc. The 5% not covered in ice is still largely unexplored, though. Land vehicles are not allowed over most of the continent, so the only way to get to most of these places is by helicopter. Scientists explore new places every year, but with all the harsh extremes of the continent, it will take a while before the continent is fully explored.