Topography 8.9C

The satellite image below shows a portion of the Namib Desert in Africa. This is an ancient, sandy desert with dunes that can be up to 305m tall. The Namib Desert extends inland from the Atlantic Ocean between 80 km and 200km and receives only 5 mm to 76mm of rain each year. A satellite picture of this same area taken weeks before shows that the shape and location of some sand dunes have changed. Which of these most likely caused the changes in the dunes?

• Ocean waves
• Flowing rivers
• Blowing wind
• Crustal uplift

This satellite photograph shows an area in Alaska after a fire occurred. Which statement best describes the most likely affect the fire had on the river in the 12 months after it occurred?  

• Less sediment flowed into the river because the fire heated up the soil and made it drier.
  
• The amount of vegetation increased and less sediment flowed into the river because the fire produced ash that mixed with the soil.
  
• More sediment flowed into the river because the fire destroyed most of the vegetation holding the sediment in place.
  
• More sediment flowed into the river because the fire disrupted animal habitats and caused animals to leave the area.
  

What is the elevation at point X?

• 900km
• 1000km
• 1500km
• 1600km

What is the difference in elevation between point B and point X?

• 1600km
• 900km
• 700km
• 100km

The topographic map shows the location of a park ranger at Point X when a message is received that an injured hiker needs help at Point Z. Which of these is closest to the difference in elevation between the locations of the ranger and the injured hiker?

• 2,050 m
• 450 m
  
• 910 m
  
• 3,650 m