From icecap to iceberg. (Diagram-Reading And Critical-Thinking Skills).Name: -- Like all deserts, most of Antarctica receives less than 25 centimeters (10 inches) of precipitation precipitation, in chemistry precipitation, in chemistry, a process in which a solid is separated from a suspension, sol, or solution. In a suspension such as sand in water the solid spontaneously precipitates (settles out) on standing. per year. So how did a 2,438 meter (8,000 foot)-thick layer of frozen water, or icecap, form on Earth's driest continent? The answer: Very gradually. Because Antarctica is so cold, most of the snow that falls on the continent never melts. And over millions of years the snow built up and compacted into the icecap, In "Icebergs: Top to Bottom" (p. 14), you learned all about icebergs. Without looking at the article, use complete sentences to describe the step-by-step iceberg-making process in the spaces provided below. Also, label the blanks in the diagram with the corresponding word (icecap, iceberg iceberg, mass of ice that has become detached, or calved, from the edge of an ice sheet or glacier and is floating on the ocean. Because ice is slightly less dense than water about one ninth of the total mass of a berg projects above the water. , ice shelf). Don't Stop Now: Ninety percent of the world's icebergs come from Antarctica. Where do the rest come from? Do they form by the same process as Antarctic icebergs? [ILLUSTRATION OMITTED] ANSWERS 1. Snow dusts the South Pole South Pole, southern end of the earth's axis, lat. 90° S. It is distinguished from the south magnetic pole. The South Pole was reached by Roald Amundsen, a Norwegian explorer, in 1911. See Antarctica. . 2. The snow builds up inch by inch over millions of years into a compact freshwater ice dome, or icecap. 3. This icecap flows down the continent to the ocean, where it becomes an ice shelf. 4. The ice shelf floats on seawater seawater Water that makes up the oceans and seas. Seawater is a complex mixture of 96.5% water, 2.5% salts, and small amounts of other substances. Much of the world's magnesium is recovered from seawater, as are large quantities of bromine. up to 1,000 feet deep. 5. Chunks of ice calve calve act of parturition by a cow or other mammal producing a calf as offspring. off the ice shelf, crashing into the ocean as icebergs. 6. Ocean currents carry icebergs away form Antarctica. Eventually, they melt into the sea. Don't Stop Now: Most Northern Hemisphere icebergs originate from glaciers This is a list of glaciers. Due to somewhat sparse information, some glaciers, especially those in the tropics, may no longer exist as listed. This is especially true for glaciers in Africa and New Guinea. on the coast of Greenland. Bergs calve off the glaciers by the same process they do in Antarctica; however, Greenland's bergs can't compare in size with Antarctica's. |
|
||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion