The Highlands

1. The Highlands Page 143 questions 2, 3, 4, 5, 6

2. #2 ) Why does the Appalachian region have many excellent harbours? • During the last ice age the weight of the continental glaciers pushed the crust of the earth downwards. • When the ice melted, the ocean was able to move up the river valleys creating a flooded coastline • This caused the river beds to be much deeper under water than expected. • The result is that cities such as Halifax have very deep harbours which make them important centres for large ocean going ships.

3. http://images.marinas.com/med_res_id/107570

4. How ice weighs down the earth’s crust Photos by Doc Bacon

5. #3a) Describe the composition and appearance of the InnuitianMountians. • The Innuitian Mountains have been described as icy watchtowers in Canada’s north. • The have the same composition (mostly sedimentary & some metamorphic rock) as the Appalachians. • Because they are younger they have higher (2500 m) and sharper peaks since they have not been eroded as much. • They are mostly ice covered and barren since the climate is so cold and the growing season so short.

6. #3b) Why has this region not been developed as much as other regions? • Few people live in the area, and there are no roads, few harbours, and no airports (and only a few airstrips) to allow access. • Therefore, because of its remote location, harsh climate, and because the same types of resources can be found and developed more economically in the south, this region remains undeveloped.

7. #4a) How were the fiords of British Columbia created? • During the last ice age alpine glaciers occupied the river valleys leading out to the sea. • The glaciers eroded the bottom of these valleys until they were deeper than today’s sea level. • When the glaciers melted, the ocean flooded the valleys creating steep sided fiords.

8. #4b) What effect do the fiords have on transportation along the coast? • The deeply indented coastlines created by the numerous fiords make road construction expensive and difficult. • For this reason transportation is mostly by boat and by float plane.

9. #5) Explain why the west coast of Canada has so many earthquakes. • The west coast suffers from many earthquakes because it is the site of the collision of the North American and Pacific tectonics plates. • The two plates are moving past one another at speeds of 2 to 10 cm per year. • The Geologic Commission of Canada has recorded more than 100 earthquakes of magnitude 5.0+ in the past 70 years, making the west coast the possible site of a tsunami.

10. West coast earthquakes

11. #6) Which mountains are older ? How can you tell? The Western Cordillera (left) are youngest They have a sharper more jagged appearance since they have had less time for erosional forces to work. The Appalachian Mountains (left) are oldest. They have a more rounded shape and have been more eroded. A second indicator is the general height of each mountain range. The lower the height the longer period of erosion The Innuitian Mountains (left) are middle-aged (like me!) and so are higher but not as jagged.