North America
1. Give the single term for the following.
a. The supercontinent that disintegrated to form the present continents.
= Pangaea;
b. The German geophysicist who promulgated the theory of continental drift.
= Alfred Wegener;
c. A narrow land mass linking North and South America.
= Isthmus of Panama;
d. World's greatest inland water body.
= Lake Superior;
e. The narrow stretch of water separating Asia and North America.
= Bering Strait;
f. The type of mountain, which the Western Cordilleras characterise.
= Young Fold Mountains;
g. An oceanic ridge formed due to divergent plate boundaries.
= Mid Atlantic Ridge;
2. Give reasons to explain each of the following.
a. Volcanoes and fold mountains are a common occurrence along plate boundaries.
= The pressure of plates at the junction is so massive that the rocks can melt and erupt through volcanoes.
The fold mountains can be formed when two plates collide at the junction and fold upwards.
b. The shape of the continents of South America and Africa bears evidence to the theory of continental drift.
= The parts of Gondwanaland that contain Africa and South America form an ideal 'jigsaw fit'. This, along with other several evidences, makes us believe that the drifting of continents did take place.
c. The region around the Canadian Shield is dotted with lakes.
= The region around the Canadian Shield was covered by thick ice sheets. The denudation of the area by ice sheets has resulted in the formation of a large number of basins. These basins contain lakes at present.
d. Western Cordilleras have steep slopes and high peaks.
= Western Cordilleras are young fold mountains and they have steep slopes and high peaks.
3. Explain the differences between the following.
a. Laurasia and Gondwanaland.
= Laurasia forms the major part of North America and it is located in the North Hemisphere.
Gondwanaland forms the major part of South America and it is located in the Southern Hemisphere.
b. Convergent and divergent movements.
= When two plates move towards each other and collide, the weaker plate usually slips below the more stable one. This is known as Convergent movement. Volcano and fold mountains formed because of these movement.
When two plates move away from each other and as a result the ocean floor begins to spread. This is known as divergent movement. Often magma may erupt from the interior and create new landforms because of this type of movement.
c. Western Cordilleras and Eastern Highlands.
= Western Cordilleras are young fold mountains. They have steep slopes and high peaks. The Western Cordilleras have many peaks, which exceed 4,000 metres above sea level.
Eastern Highlands are old fold mountains. They have denuded peaks and slanting slopes. The peaks in this range do not exceed 2,100 metres in altitude.
4. Answer the following questions.
a. Explain the arrangement of oceans and continents before they started drifting apart.
= It is believed that continents and oceans were formed millions of years ago. The seven continents as they appear today were joined together in one huge continental mass or supercontinent called Pangaea. The Pangaea was surrounded by a large mass of water of universal ocean known as Panthalassa.
b. Enumerate the major seas and oceans surrounding the continent of North America.
= The continent of Asia is bounded by the Arctic Ocean in the North; the Gulf of Mexico and the Caribbean Sea in the South; the Atlantic and Pacific Ocean wash its eastern and western shores, respectively.
c. Why have deserts developed in the south-western part of North America? Name the important deserts of this region.
= The existence of the Western Cordilleras created rain-shadow conditions that led to the formation of four important desert regions, all in the south-western part of the continent of North America.
The names of the important deserts of this desert are - Great Basin Desert, Mojave Desert, Sonoran Desert, Chihuahuan Desert.
d. List any three countries of North America. Also mention the capitals of each of the three nations.
= Three countries of North America along with their capitals are -
Canada - Ottawa;
The United Mexican States - Mexico City;
The United States of America- Washington, D.C.;
5. Answer the following questions on lumberjacks.
a. What does the term 'lumbering' mean?
= The term 'lumbering' means to the harvesting of timber and finally chopping them into required shapes and sizes.
b. Why do you think a lumberjack's life is full of hardships?
= A lumberjack leads an isolated life which is full of hardships. They set out in autumn to live in temporary wooden houses, or shanties, with steep roofs. Sometimes, constructing a house becomes a problem due to permanent frost on the ground. Therefore, in summer, the lumberjacks build many kilometres of rough track roads deep into the forest. This road leads to lumber camps. A lumber camp consists of a few buildings with a kitchen, a dining room and a bedroom. Besides all these, they do a risky job from cutting to moving the timbers to the mills. They face their death in every steps of their job.
c. What are the favourite pastimes of a lumberjack after a hard day's work?
= After a whole day's hard work in the forest, the lumberjacks seek relaxation in activities such as swapping stories, fighting, and socialising.
d. Who is a high rigger? What is his work?
= High rigger is a kind of lumberjack who climb the tall trees and cut the branches and finally chop the top of the tree by their axe or saw.
e. How are the lumbers are transported to their destinations?
= On large rivers, the logs are looped or chained together to make rafts and thus, their movement is controlled. The Haulers are involved in moving the logs down the stream. They use long spiked poles to separate the logs as they float down to the saw mills. This works starts when the ice thaws in spring.
f. What changes have occurred in the life of the lumberjacks in recent years?
= The life of the Canadian lumberjacks is on the way to modernisation. Following the introduction of a wide range of modern scientific tools and new techniques of lumbering, the task of the lumberjacks has become much easier than that of their predecessors. Many lumberjacks earn huge amount of money after working for several years in the log farms.
6. Thought provoking questions.
a. Why is lumbering a major occupation in Canada?
= Canada has a highly developed lumbering industry because of many reasons. These include the following :
❐ Abundance of hydroelectric power from the streams.
❐ Enormous resources of coniferous softwood trees.
❐ Modern mechanised mills.
❐ Excellent railway and water transportation.
❐ Relatively small population.
b. Who amongst the different categories of lumberjacks does the most difficult work? Why?
= The High Riggers do the most difficult work amongst the different categories of lumberjacks.
They climb the tall coniferous trees, such as spruce, balsam, fir, pine, hemlock and poplar, and cutting the branches. They wear spiked shoes and cling to the tree with the help of a safety belt slung around them and the tree. Finally, the top of the tree is chopped by their axe or saw.
c. How has the transport system for lumberjacks improved?
= Presently their work of movement of the logs has been made easier by dams that regulate the flow of the water and direct it towards the saw mills and paper mills.