Question

1.  
   1. Distinguish between an ice sheet and ice cap.  
   2. Describe two ways through which ice moves.   
2. Explain three factors that influence glacial deposition.    
3. Study the diagram below showing features in a glaciated upland region. Use it to answer the questions that follow,
            
   1. Name the types moraines marked X, Y and Z.    
   2. Describe how an arête is formed.    
   3. Explain the significance of upland glaciated features to human activities.   

Answer 1

1.  
   1. Ice sheet is a large and continuous mass of ice which covers vast areas of a lowland while ice cap is a small mass of continental glacier that covers plateaus and high altitude areas.
   2.  
      • Basal slip-weight of the ice exerts pressure on the lower layers which thaws/melts causing ice to slide over the underlying rocks under the influence of gravity
      • Plastic flowage-the weight of the ice exerts pressure on the lower layers leading to slight melting of the ice and eventually moving as a viscous mass
      • Extrusion flow- The internal movement of ice in an area of accumulation in lowlands where the weight of ice compresses the underlying layers resulting to ice spreading to where is less pressure.
      • Internal shearing-the differential sliding of ice along planes caused by great downslope pressure.
2.  
   1. Climate change/rising temperatures
      Rising temperature leads to melting of ice thereby causing ice to deposit its load.
   2. Gradient/relief of the land
      Change of gradient to relatively flat surface will reduce the velocity of the glacial movement which will subsequently lead to deposition of glacial materials.
   3. Alternating warm and cold periods lead to seasonal melting of ice which allows ,materials embedded in the ice to be released and deposited.
   4. Stagnation/accumulation of the glacier leads to pressure at the base of the glacier which in turn leads to melting of ice at the base causing embedded materials to be released and deposited.
   5. Friction at the base and sides of the glacier and a rough surface leads to melting of ice and deposition of water.
3.  
   1.  
      • X-Terminal moraine
      • Y-Medial moraine
      • Z-lateral moraine
   2.  
      • Snow accumulates in two adjacent pre-existing shallow depressions on the mountain side.
      • The snow accumulates and are compacted into ice.
      • Freeze-thaw action acts on the depression causing deepening of the depression.
      • More ice accumulates in the depressions.
      • The ice move downslope and erosion through plucking and abrasion occurs to form two adjacent cirques
      • Further plucking and abrasion deepens and enlarges the cirques
      • Plucking of the backwalls leads to backwall recession of cirques
      • Eventually a steep knife-edged ridge separating adjacent cirques is formed called an arête
   3.  
      • Glaciated highlands especially mountains are a tourist attractions
      • Waterfalls from hanging valleys are ideal sites for generation of H.E.P
      • Glaciated valleys have good pasture in summer used for grazing.
      • Fiords form suitable sites for construction of natural harbors.
      • Sheltered waters in the fiords provide suitable breeding grounds for fishing thus encouraging fishing
      • Some glacial troughs form natural waterways.