******************************************************** VOLCANOES ******************************************************** ********************** GEOTHERMAL POWER ********************** __________ QUESTION: Has anyone explored geothermal power generation where the ice sheets aren't too thick? ANSWER from Guy Gutheridge on January 24, 1995 McMurdo Station is close to Mount Erebus, which is an active volcano. In the 1970s, when fossil fuel prices were rising rapidly, people were optimistic that volcanic heat from beneath the Earth's surface could be captured to heat and power McMurdo Station. In January and February 1973, two holes of the international Dry Valley Drilling Project (mainly a project in fundamental research in the earth sciences) were drilled at McMurdo Station, next door to the then earth science lab. The holes went as deep as 201.5 meters (661 feet), but even the bottoms were in permafrost. Engineers concluded that drilling deep enough to reach geothermal heat would cost more than using conventional sources. ******************************* MT. EREBUS CHARACTERISTICS ******************************* __________ QUESTION: Have any of the scientists there explored the volcano on Antarctica? How is it different from regular volcanoes? ANSWER from Nicole Wertz on Dec. 20, 1994: In answer to the first part of your question, yes. There have been many scientists who have studied many different areas of Mt. Erebus, our own locally active volcano. Mt. Erebus is different from other volcanoes in several ways. First of all, it has a small lava lake in the crater, which is not too common. Second, because Mt. Erebus is in such a cold climate and has a lot of snow and ice on it, it is possible that some old lava flows have actually run over snow and ice fields without melting them. This is possible because the ice cools the bottom of the lava very quickly, forming a crust which prevents heat from conducting rapidly to the bottom and melting all of the ice. So there may very well be some layers of ice trapped between old lava flows. Lastly, Mt. Erebus is very unusual in the chemical composition of the lava lake and many of the younger flows. This type of volcanic activity was once widespread in the past, but is now only found here and at Mt. Kenya in Africa. ******************** BIGGEST ERUPTION? ******************* __________ QUESTION: What was the biggest eruption of Mount Erebus? ANSWER from Lisa Gahagan on January 20, 1995 The biggest historical eruption of Mount Erebus was the one viewed by Captain James Clark Ross when he sailed into the region in the eighteenth century. ********************** EFFECTS OF ERUPTION ********************** __________ QUESTION: What would happen to Ross Island and Antarctica if Mt. Erebus erupted? ANSWER from Lisa on Dec. 19, 1994 In some ways Mt. Erebus is presently erupting. People think of eruptions in terms of Mt. St. Helens (in southern Washington State near Portland, Oregon) blowing its crater away with catastrophic loss of life and property. On the other hand, Kilauea on the big island of Hawaii has an active lava lake that occasional splats some molten lava about. Some tourists even walk on top of the cooled lava as the molten rock flows under their feet and pours into the ocean. That is actually a good way to get yourself cooked and boiled in one swift motion and should not be tried by anyone, particularly adults who should know better. If you can feel the heat of the rock through your shoes, you shouldn't be there. So it all depends on how violent Mt. Erebus erupts. If it continues its present activity with occasional boulders (up to the size of a car) being thrown a few hundred meters or so, there is really no danger to anyone except to the small group of people who are studying the volcano. In fact, that is why the Dante project tried to develop a robot that looked like a large spider that was supposed to crawl down into the crater. When not throwing up large rocks, the volcano does emit poisonous fumes. On the other hand, if it really erupts, much like Deception Island on the Antarctic Peninsula did in 1969 (when it destroyed a Chilean research base and severely damaged a British base), it could cover large areas with pumice and ash. Since that alone would disrupt the air traffic around McMurdo station, a full-blown eruption of Mt. Erebus would definitely cause problems but would probably not result in any immediate loss of life. Mt. Erebus is the most studied volcano in Antarctica, having been the subject of research since it was discovered in 1841 (Kyle, 1990 in the above reference). It appears to have formed between 940,000 years ago and 150,000 years ago. Although it is still active as described above, it is now in a phase where it is huffing and puffing but not really blowing up. So while Mt. Erebus throws a few rocks around in its crater and emits noxious fumes, it has not produced a substantial amount of material in the recent past 100,000 years. Deception Island is a more likely candidate for producing a threatening eruption in the near future as it did in 1969. There is an excellent reference book titled "Volcanoes of the Antarctic Plate and Southern Oceans" by Le Masurier and Thomson as editors. It is available from the American Geophysical Union in Washington, D.C. It is volume 48 of the Antarctic Research Series. AGU can be contacted at 1-800-966-2481. **************************** VOLCANOES UNDER THE ICE? **************************** __________ QUESTION: Does the ice stop the under-ice volcanoes from erupting? Where are these volcanoes located on Antarctica? ANSWER from Lisa Gahagan on December 23, 1994: Volcanoes occur at all latitudes in places like Indonesia, Hawaii and Japan as well as in Alaska and Antarctica. The heat for volcanoes comes from deep within the earth. Whether the ice will stop a volcano that is underneath it from erupting depends on how thick the ice is and how big the volcano is. If the ice is thick and the volcano small, the ice will probably stop the volcano from erupting as we know it. If the ice is thin, the volcano will probably erupt. An active volcano under the ice will cause the ice to melt above it which leaves a depression on the surface of the ice. Scientists use lasers to make surface maps of the ice and locate these depressions. Antarctica has many volcanoes. The one on Mount Erebus is at 77.53S, 167.17E. The one on Deception Island which erupted in 1969 is at 62.95S, 60.63 W. Both of these are above the ice. Recently scientists have located what they think is a volcano under the ice at 81.9S, 111.3W.