Antarctica
1. Choose the correct option.
a. The white continent refers to
i) Australia. [ ]
ii) Antarctica. [✓]
iii) Europe. [ ]
b. Antarctica lies closest to
i) Australia. [ ]
ii) South America. [ ]
iii) Asia. [✓]
c. The sun never sets in Antarctica during the month of
i) January. [✓]
ii) October. [ ]
iii) June. [ ]
d. The southernmost active volcano of the world is
i) Mt Vinson. [ ]
ii) Mt Erebus. [✓]
iii) Mt Sidley. [ ]
e. The waters of this ocean wash the coast of Antarctica
i) Pacific. [✓]
ii) Atlantic. [ ]
iii) Southern. [ ]
2. Name the following.
a. The mountain range joining Lesser and Greater Antarctica.
= Trans-Antarctic.
b. The eastern coastal area comprising mountain of ancient granite and gneiss.
= Queen Maud Land.
c. One of the largest glaciers of the world.
= Beardmore Glacier.
d. The highest volcanic mountain of Antarctica.
= Mt. Sidley.
e. The highest mountain peak of Antarctica.
= Mt. Vinson.
f. The largest sub-glacial lake discovered till date.
= Lake Vostok.
g. Radiant lights that illuminate the dark winter skies of Antarctica.
= Aurora Austrilis.
h. The gas that protects us from the harmful ultraviolet rays of the Sun.
= Ozone.
i. India's latest research station in Antarctica.
= Bharati.
3. Give reason for the following:
a) Mosses, lichen and algae are the only form of vegetation found here.
= Mosses, lichens and algae are the only form of vegetation found here because the severe weather conditions do not support vegetation.
b) Antarctica is devoid of permanent human habitation.
= Antarctica is devoid of permanent human habitation because of the long months without sunlight, lack of rain, extreme cold, harsh weather and absence of vegetation.
c) The size of Antarctica has begun to shrink.
= The size of Antarctica has begun to shrink due to the melting of ice shelves.
d) Pollution of the environment in Antarctica is on the rise.
= Pollution of the environment in Antarctica is on the rise because of the oil spills caused by increasing shipping activity in the region.
e) The Madrid Protocol is of great significance.
= The Madrid Protocol is of great significance as it banned mining in Antarctica indefinitely. That prohibits any type of commercial activities in the continent.
f) The ozone hole over Antarctica is a worrying phenomenon.
= The ozone hole over Antarctica is a worrying phenomenon as thinning of ozone layer will allow ultra-violet rays to reach these parts of the Earth, thereby affecting living beings adversely.
4. Answer the following questions:
a) Give an estimate if the size of Antarctica.
= Antarctica is the fifth largest continent stretching over 1,40,000 square kilometres. It is larger than Europe and Australia and about four times the size of India.
b) Write about the early explorations of the continent Antarctica.
= The continent was first discovered in 1820 by Russian explorers. Detailed exploration of the continent commenced in the beginning of the 20th century. Roald Amundsen of Norway and Falcon Scott of England further explored different parts of the continent.
c) Explain the location of Antarctica in your own words.
= Antarctica is the southern most continent which contains the geographic south pole. The part of the continent that lies in the Eastern Hemisphere is known as Greater Antarctica. It is considerably larger than the part that lies in the Western Hemisphere, which is known as the Lesser Antarctica.
d) Why is Antarctica called the 'White Continent'?
= The Antarctica is permanently frozen, and the land surface is covered with thick ice sheets whose thickness varies from 2,000 metres to 5,000 metres. Owing to the permanent cover of ice on its land surface, Antarctica is called the White Continent.
e) Describe the physical features of the continent of Antarctica.
= The continent is covered with thick ice sheets whose thickness varies from 2,000 metres to 5,000 metres. So, it is called the White Continent. There is Antarctic Plateau or the Polar Plateau to the east of Antarctica. It has over a diameter of about 3,000 metres. Some areas are exposed as steep mountains slopes made of ancient granite and gneiss rocks.
There is vast Trans-Antarctic Mountains between Lesser Antarctica and Greater Antarctica. There are many volcanoes like Mt. Erebus, Mt. Sidley. Mt. Vinson is the highest mountain peak in Antarctica. There is Beardmore Glacier, one of the largest glaciers of the world.
There are icebergs in the oceans around Antarctica. Several large lakes lay buried under the thick Antarctic ice. Lake Vostok is the largest lake of Antarctica.
f) During which months does Antarctica experience Summer and Winter respectively.
= Antarctica experiences summer during the months of November to February. And it experiences winter during the months of May to August.
g) Write short notes describing the summer and winter seasons of Antarctica.
= Summer season of Antarctica:- Summer months extend from November to February. Average temperature is about 0℃ . The sun never sets and the continent has 24 hours of sunshine. Because of highly reflective ice and snow covered surfaces, most of the sun light gets back to the sky and ice does not melt.
Winter season of Antarctica:- Winter months extend from May to August, there is darkness 24 hours a day. A temperature of -60℃ to -70℃ is common during this time. The average temperature is around -50℃. Snow Storms or blizzards are common occurances.
h) Why is Antarctica called a cold desert?
= The huge Antarctic Plateau or the Polar Plateau has an elevation of about 3,000 metres. This high elevations along with its high altitudes and extremely long dark winters, make it the coldest region of Antarctica and of the entire world. Antarctica is the largest cold desert on Earth.
i) What type of vegetation can be found in Antarctica?
= The only plants that can be found in Antarctica are - lichens, mosses and algae.
j) Name some of the minerals discovered in Antarctica. Why are they not commercially exploited?
= Explorations have taken place to find minerals in the land mass below the ice sheets. Coal, iron ore and copper ores along with several other minerals have been located at different places across the continent.
The minerals are not commercially exploited because in 1991, the Protocol on Environmental Protection(the Madrid Protocol), banned mining in Antarctica in definitely.
k) Why is Antarctica devoid of any native population?
= Antarctica is devoid of any native population because of its long months without sunlight, lack of rain, extreme cold, harsh weather and absence of vegetation.
l) Discuss at least three significant threats that the continent of Antarctica is experiencing in recent times.
= Three significant threats that the continent of Antarctica is experiencing in recent times are -
i) The ice sheets of Antarctica is melting because of global warming. It will; lead to an increase in the sea level of the Earth. This will submerge the coastal areas of many continents.
ii) Reduction of ice cover threatens the existence of many living organisms. This effect the entire Antarctic eco-system.
iii) More scientists and more tourists visit Antarctica now-a-days. This increased shipping activity. The oil spills due to the shipping activity causes more pollution in Antarctica.