back to index ofchapters1. When did Gondwanaland begin to break up and where did the continentsgo?
Ans. About 500 million years ago, Australia and New Zealand were connectedto Antarctica in the super continent Gondwanaland. About 85 million yearsago, forces in the earth caused Gondwanaland to break up. As Australia andNew Zealand drifted north, Antarctica drifted south gathering its ice sheetsfrom water in the air.
2. What is continental and pack ice composed of?
Ans. Two types of ice are found in Antarctica. The ice sheets shown inFigure 269.1 are made of continental ice which is composed of fresh water.These ice sheets contain the original mountains of the continent and manyglaciers. Because this ice formed over a long period of time, it containsan accurate record of the earth's climate over millions of years. The secondtype of ice is made from sea water and forms the pack ice shown in Figure269.2.
3. How do icebergs form?
Ans. Icebergs can form from glaciers which break off from the mainland(See Figure 270.2).
4. What happens when krill downsize?
Ans. Krill survive the Antarctic winter's conditions because when theyreduce their body size, they use the discarded protein in their own bodiesas food.
5. How much more oxygen is dissolved in Antarctic waters compared totropical waters?
Ans. Since gases are dissolved more easily at colder temperatures, thereis almost twice as much oxygen in Antarctic waters as there is in tropicalsea water.
6. What is the name of the zone around Antarctica where the warm tropicalwaters sink under the colder polar waters?
Ans. The Antarctic convergence is a distinct region where the warmernorthern waters sink below the cold Antarctic currents (Figure 269.3). Thearea is about 40 km wide and contains many icebergs as shown in Figure 270.1.
7. What are krill?
Ans. Krill is a general term used to describe about 85 per cent of open-oceancrustaceans.
8. Name nine animals that feed directly off krill.
Ans. See Figure 271.1
9. How do penguins swim underwater?
Ans. On the land they walk with difficulty but are great underwater swimmerswhen they tuck their wings and legs in close to their bodies to become streamlined.
10. How big is an Adélie penguin?
Ans. The Adélie is a medium-sized penguin that stands about 0.7m tall and feeds mainly on krill.
11. What is so special about the stomach of an Adélie penguin?
Ans. The stomachs of Adélie penguins contain antibiotics whichsterilise the food while it is stored there which allows the parents tofeed the chicks small portions of krill each day. These antibiotics preservethe food for several weeks.
12. Which parent incubates the emperor penguin's eggs?
Ans. After each pair's single egg is laid, the male takes over the incubationwhile the female leaves the nest to fish at sea. The males then keep theeggs between their legs and on top of their feet for about 70 days untilthey hatch.
13. Which seals are the world's greatest consumer of krill?
Ans. Marine scientists estimate crabeater seal populations consume over100 million t of krill a year, possibly making them the world's largestconsumer of this food source.
14. How do weddell seals keep their breathing holes open in winter?
Ans. During this time they use their teeth to keep open small holes inthe ice.
15. What is the term given to the behaviour when a seal crawls out ofits hole?
Ans. Hauling out
16. Why were elephant seals killed in the first half of the 20th century?
Ans. They have a thick layer of blubber and for many years they werehunted and their carcasses boiled down to make oil.
1. New Zealand students can check out their home page on:
· http://www.antarcticanz.govt.nz/
2. Australian students can check out their home page on:
· http://www.antdiv.gov.au/
3. Use your web sites to find out:
a. how to survive at 50o below zero;
b. getting around Antarctica;
c. Antarctic stations and their buildings and
d. Antarctica's ice fields.
Suggestions:
Use web sites
4. Use your web site to find a picture and write a paragraph about anytwo of the following
Crustaceans - krill
Penguins - Adélie, chinstrap, emperor, gentoo, king, rockhopper,royal
Flying seabirds - grey-headed albatross, short-tailed shearwater, antarctictern, blue-eyed cormorant, southern fulmar
Seals - crabeater, elephant, fur, leopard, weddell
Whales - blue, humpback, minke, orca, sei
Suggestions:
Use web sites to download information
5. Locate the following web site, print it out and then draw a graphof the distances from Hobart and Christchurch to the bases in Antarctica
http://www.antdiv.gov.au/misc/antmap_km.html
Suggestions:
Use web sites to download information
6. Find the article written by Wendy Rockliffe on Understanding Antarctica:Recycling in Antarctica
http://www.antdiv.gov.au/aad/p%26p/is/antarctic_information/recycling.html
· Describe how the author feels about human invasion of the continent
· Write a paragraph on ways scientists are attempting to reducetheir impact on the continent
Suggestions:
Use web sites to download information
7. Figure 276.1 shows a group of penguins huddled together in a katabaticwind. Find our how these winds are formed and how dangerous they are.
Suggestions:
Use library and index.
8. What are nunatacks and ablations?
Suggestions:
Use library and index.
9. Who was Douglas Mawson and why is he famous?
Suggestions:
Use library and index.
10. Read the book - The Fire in the Snow.
Suggestions:
Take it out from your library.
11. Arrange a visit to your local Antarctic centre Kelly Tartonsin New Zealand or Australian Antarctic Division in Tasmania.
Suggestions:
If locally arrange trip. Otherwise look at web site.
12. What role has Greenpeace played in Antarctica?
Suggestions:
See Greenpeace home page
1. Gondwanaland
2. ice sheets
3. climate
4. Icebergs
5. Australian National Antarctic Research Expeditions)
6. Antarctic
7. protein
8. regurgitating
9. blubber
10. insulates
11. Crabeater Seal
12. consumer
13. harems
14. extinction
15. harvesting