Tales from the ice: each year scientists venture south to Antarctica, Earth's most desolate continent. They bore deep into glaciers to draw out long rods of ice. Why? Clues to the mysteries of global warming are frozen within. (Earth Science: Global Warming. Ice).When it comes to America's weather, things are heating up. In 2001, the U.S. sizzled in the fifth-hottest summer on record. Residents of the Central Plains sweltered through record-breaking daily temperatures--higher than 32 [degrees] C (90 [degrees] F), or even 38 [degrees] C (100 [degrees] F)--during most of July and August. In fact, since 1975 Earth's surface Noun 1. Earth's surface - the outermost level of the land or sea; "earthquakes originate far below the surface"; "three quarters of the Earth's surface is covered by water" surface temperature has climbed 0.5 [degrees] C (1 [degrees] F). That number may sound insignificant, but over time such small increases could lead to severe global flooding or droughts. And many scientists predict the planet's temperature will continue to rise throughout this century. What's turning up the heat? Many experts point the finger at global warming global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. , or Earth's warming climate. They think the trend is the result of factories, power plants, and vehicles choking the air with waste gases like carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. , which trap the sun's heat (see SW 9/3/01). But is global warming a human-induced trend? Or is it natural for Earth to experience cycles of severe hot and cold climate patterns? That's what climatologist cli·ma·tol·o·gy n. The meteorological study of climates and their phenomena. cli  ma·to·log (weather scientist) Debra Meese at Cold Regions Research and Engineering Lab in Hanover, N.H., is trying to find out. And she trekked to Antarctica to do it. "I was on a ship for three and a half months," Meese says. "We were out of contact with the world--we might as well have been on Mars." With temperatures as low as -89 [degrees] C (-129 [degrees] F), Antarctica's ice and snow rarely melt. In some places you'd have to plow aside 500,000-year-old ice to glimpse Antarctic rock. But what can age-old ice tell scientists like Meese about today's warming climate? If you've ever seen roadside snow turn dirty over time, you know that ice traps dirt and dust particles. And tiny bubbles in ice cubes prove that gases can get snared, too. So Antarctica's 4 km (2.5 mi)-deep layer of ice contains loads of particles and gases from the atmosphere: ice-locked clues of Earth's climate history. Some particles, like ash from erupting volcanoes, for example, block the sun's rays from reaching Earth. With less sunlight, the planet chills. On the other hand, industrial pollution--gases like carbon dioxide, methane, and nitrous oxide nitrous oxide or nitrogen (I) oxide, chemical compound, N2O, a colorless gas with a sweetish taste and odor. Its density is 1.977 grams per liter at STP. It is soluble in water, alcohol, ether, and other solvents. , as well as black carbon soot--allows the sun's rays to pass through the atmosphere, but doesn't allow heat to escape. Like glass on a greenhouse, pollution traps heat in the atmosphere--and warms up global temperatures. As these particles and gases float through the atmosphere, some fall onto Antarctica's top layer of snow. And they become trapped under the next year's snowfall. To get to ancient ice, scientists use a 30-m (98-ft) drill. It bores deep into the glacier, extracting a popsicle-shaped ice core (rod of ice) between 2 to 6 m (7 to 20 ft) long. By drilling deeper each time, one group of researchers retrieved a 3,610 m (11,843 ft)-long ice core. This ice holds records of how Earth's climate has changed over the past 420,000 years! The ice cores prove that Earth naturally undergoes warm and cold cycles (see sidebar, p. 21). But climatologists have also found more greenhouse gases in recent ice layers. So some scientists hotly debate whether the current warming trend is part of Earth's natural cycle, or if excess consumption of greenhouse gas-emitting fossil fuels (coal, oil, and natural gas) is to blame. Why should we care if our climate warms? If some species can't adapt to rising temperatures, they may die out. A warmer planet can lead to more droughts, which impacts world food production, and the spread of diseases. And climbing temperatures could melt Antarctic and Greenland glaciers, raising sea levels by more than 70 m (230 ft) and submerging entire coastal regions. The U.S., home to only 4 percent of the world's population, spews 25 percent of all greenhouse gases into the atmosphere. How can you help reduce air pollution? [ILLUSTRATION OMITTED] Cross-Curricular Connection History: Research and report on an early Antarctic explorer (Roald Amundsen, Ernest Shackleton Sir Ernest Henry Shackleton CVO, OBE (15 February 1874 – 5 January 1922) was an Irish explorer who was knighted for the success of the 1907-09 "British Antarctic Expedition" under his command. , etc.). What were some of the life-threatening factors they faced? Did You Know? * Antarctica is the only continent that is not ruled by a set government. The Antarctic Treaty, signed in 1959, governs people's actions there. It stipulates that the continent should be used for peaceful purposes only. Military activity prohibited. * The temperature of Antarctic sea ice dips to -20 [degrees] C (-4 [degrees] F). Inside the crystallized crys·tal·lize also crys·tal·ize v. crys·tal·lized also crys·tal·ized, crys·tal·liz·ing also crys·tal·iz·ing, crys·tal·liz·es also crys·tal·iz·es v.tr. 1. water and brine brine a salt solution used in the curing of meat. Standard ingredients are sodium chloride (15 to 30%) and sodium nitrate (0.15 to 1.50%) but many other ingredients may be added for special effects. brine shrimp see artemia. , algae algae (ăl`jē) [plural of Lat. alga=seaweed], a large and diverse group of primarily aquatic plantlike organisms. These organisms were previously classified as a primitive subkingdom of the plant kingdom, the thallophytes (plants that thrive. * Antarctica is largely responsible for producing the cold deep water that drives Earth's ocean and atmospheric circulation Atmospheric circulation is the large-scale movement of air, and the means (together with the smaller ocean circulation) by which heat is distributed on the surface of the Earth. . ANSWERS CHECK FOR UNDERSTANDING, p. TE4 Science to the Rescue Answers will vary but should include the following points. 1. Before workers climb into wreckage, search-and-rescue dogs sniff the rubble for human scent. Dogs are good at sniffing for bodies because they have 220 million olfactory olfactory /ol·fac·to·ry/ (ol-fak´ter-e) pertaining to the sense of smell. ol·fac·to·ry adj. Of, relating to, or contributing to the sense of smell. receptors--40 times more than a human nose. 2. The "bathtub" beneath the World Trade Center is a 16-acre, 70-foot-deep container lined with a 3,000-foot-long waterproof wall. It was built to withstand pressure and to keep tons of silt, water from the Hudson River Hudson River River, New York, U.S. Originating in the Adirondack Mountains and flowing for about 315 mi (507 km) to New York City, it was named for Henry Hudson, who explored it in 1609. Dutch settlement of the Hudson valley began in 1629. , dirt, and landfill from collapsing or seeping seep intr.v. seeped, seep·ing, seeps 1. To pass slowly through small openings or pores; ooze. 2. To enter, depart, or become diffused gradually. n. 1. into the towers' seven basement floors. Stem Cells stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastula typical of placental mammals; see embryo), which is very young : The Next Cure? 1. c 2. e 3. b 4. g 5. f 6. a 7. d Tales From the Ice Answers will vary but should include the following points. 1. In 1986, Russia's nuclear power station at Chernobyl exploded. Less than two years later, radioactive material radioactive material Radiation A substance that contains unstable–radioactive–atoms that give off radiation as they decay. See Radioactive decay. was found in Antarctic ice, proving pollution circulates throughout Earth's atmosphere “Air” redirects here. For other uses, see Air (disambiguation). Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly (by molar content/volume) 78% nitrogen, 20.95% oxygen, 0.93% argon, 0. . Also found in recent ice layers: more greenhouse gases, including methane. These gases are believed to be major culprits in causing global warming, or a rise in global temperatures. 2. Industrial pollution--greenhouse gases, like methane and carbon dioxide, and black carbon soot from burning coal and diesel fuel-allows the sun's rays to pass through the atmosphere but doesn't allow heat to escape, causing global temperatures to rise. Ash from erupting volcanoes, for example, blocks the sun's rays from reaching Earth. With less sunlight, the planet chills. SCIENCE IN THE NEWS QUIZ, p. TE7 1.b 2. d 3. c 4. b 5. b 6. a 7. d 8. c 9. c 10. c National Science Education Standards The National Science Education Standards (NSES) are a set of guidelines for the science education in primary and secondary schools in the United States, as established by the National Research Council in 1996. Grades 5-8: evidence, models, and explanation * change, constancy con·stan·cy n. 1. Steadfastness, as in purpose or affection; faithfulness. 2. The condition or quality of being constant; changelessness. Noun 1. , and measurement * Earth's history Grades 9-12: evidence, models, and explanation, change, constancy, and measurement * energy in the earth's system Resources Interested in working with scientists in the polar regions polar regions: see Antarctica; Arctic, the. ? Tap into the National Science Foundation's Teacher's Experiencing Antarctica and their Web site: tea.rice.edu. Site also includes information and activity worksheets on ice cores. Antarctica by John Baines John Baines is the incumbent Professor of Egyptology at the University of Oxford and a fellow of The Queen's College. He is the author of multiple scholarly articles and publications relating to ancient Egyptian civilisation. , Steck-Vaughn, 1998 page 20 Tales From the Ice Directions: Read our story on Antarctic ice, then write a paragraph using the words provided. 1. You're studying an Antarctic ice core. Describe ice layers from recent years and what they reveal about Earth's current climate. (Chernobyl, methane, global warming) 2. Describe how the following items may affect Earth's temperature. (greenhouse gases, ash, soot) A SLICE OF ICE What scientists have found in ice cores ICE: FROM: 1987-1988 A.D. What's trapped: Radioactive material What it means for Earth's climate: On April 26, 1986, Russia's nuclear power station at Chernobyl explodes. Less than two years later, scientists find signs of the radiation thousands of miles away in Antarctic ice--one clue that pollution circulates throughout Earth's atmosphere. ICE: FROM: 1900 A.D. What's trapped: Carbon dioxide and methane, gases released from industrial plants and fuel-burning vehicles What it means for Earth's climate: Climatologists compare ice layers from 1900 and earlier. They find much higher levels of carbon dioxide and methane in ice from 1900--when people started burning more fuel. Due to today's high Today's High The intra-day high trading price. Notes: In other words, this is the highest price that a stock traded at during the course of the day. More often than not this is higher than the closing price. See also: Today's Low numbers of cars and industrial plants--such as factories, and oil and gas refineries--current levels have risen even higher. Scientists worry the increase of such gases will further raise Earth's temperatures. ICE: FROM: 1400 A.D. What's trapped: More sea-salt than usual What it means for Earth's climate: When polar air turns colder and mixes with warm mid-latitude air, oceans get choppy chop·py 1 adj. chop·pi·er, chop·pi·est Having many small waves; rough: choppy seas. [From chop1. and release more sea-salt. Super-fine sea-salt can float in the air. Ice from 1400 A.D. shows high levels of sea-salt, which indicates a colder Earth. Researchers estimate that for about 400 years, Earth's average temperature was between 0.5 and 1 [degrees] C (1 and 2 [degrees] F) cooler than today. This dip proved enough to freeze the Vikings out of Greenland. ICE: FROM: 73,000 B.C. What's trapped: Ash from Toba, an ancient volcano in Indonesia What it means for Earth's climate: Scientists believe Toba's ash blocked some sunlight and cooled the globe for several centuries. Temperature & Wind When you open your door during winter, does cold, outside air rush in? Or does warm, inside air pour out? YOU NEED: scissors scissors Cutting instrument or tool consisting of a pair of opposed metal blades that meet and cut when the handles at their ends are brought together. Modern scissors are of two types: the more usual pivoted blades have a rivet or screw connection between the cutting ends * tissue paper * ruler * tape * 30 cm (12 in.) of thread * pencil TO DO: 1. Cut a strip of tissue paper 4 cm (1.5 in.) wide and 14 cm (5.5 in.) long. 2.Tape one end of a 30-cm-long piece of thread to the 4-cm-wide end of the tissue paper. 3.Tape the other end of the thread to a pencil. 4. Standing inside, hold the pencil sideways so the tissue paper dangles a few inches from the ground and the closed door. 5. Open the door 8 to 30 cm (3 to 12 in.). 6. Observe which direction the paper blows. Note whether it's warmer outside or inside. CONCLUSIONS: Did the tissue paper blow toward warmer or colder air? Why? Which do you think is more dense (weighs more, but takes up the same amount of space): cool or warm air? DON'T STOP NOW: Research how temperature differences create wind. Air Power What happens when you suck
You Suck: A Love Story is the tenth novel by Christopher Moore. It is a sequel to the author's Bloodsucking Fiends on a straw dipped in water? Can air push water up a straw? YOU NEED: small bucket or 2-liter soda bottle * scissors * 20-oz soda bottle and cap * straw * Stik-Tak (wall-poster putty) * paper clip * 25 pennies * cold tap water * hot tap water TO DO: 1. If you're not using a bucket, cut the 2-liter bottle along the top of the label. Discard the top. 2. Caution: Handle with care. Use scissors to poke, then carve, a straw-size hole in the 20-oz bottle cap. The straw should fit through without crimping or folding. 3. Push a straw through the hole so that 15 cm (6 in.) of the straw sticks out from the cap bottom. 4. Use just enough Stik-Tak to make an airtight air·tight adj. 1. Impermeable by air. 2. Having no weak points; sound: an airtight excuse. airtight Adjective 1. seal around the straw on the top of the cap. 5. Seal the top of the straw with a pea-size ball of Stik-Tak. 6. Unbend the paper clip and insert it through the Stik-Tak until the clip emerges in the straw. Wiggle the clip, then remove it. 7. Put pennies into 20-oz bottle. 8. Pour enough cold water into the 20-oz bottle for it to reach to the bottom 2.5 cm (1 in.) of the straw when the cap is on. 9. Screw the cap on tightly. 10. Fill the bucket half way with hot water. 11. Submerse sub·merse tr.v. sub·mersed, sub·mers·ing, sub·mers·es To submerge. [Probably back-formation from submersion, act of submerging, from Late Latin the 20-oz bottle into the hot water. Observe. CONCLUSIONS: What happened to the cool water in the 20-oz bottle when you submersed it in the hot water? Why? DON'T STOP NOW: Research how this exercise is similar to how clouds form. (Key words: water vapor, condense con·dense v. con·densed, con·dens·ing, con·dens·es v.tr. 1. To reduce the volume or compass of. 2. To make more concise; abridge or shorten. 3. Physics a. .) |
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