Topographic Maps, Erosion, & Satellite Images

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 80km and 20 km and receives only 5mm to 76mm of rain each year. A satellite picture of this same area taken weeks before shows the shape and location of some sand dunes have changed. Which of these likely caused the changes in the dunes?

• Blowing winds

• ocean waves

• crustal uplift

• Flowing rivers

The satellite photograph below shows a large meteorite crater that is 1200m in diameter and 170m deep. This crater is located in a flat, arid part of northeastern Arizona. How will this crater most likely change over time?

• It will get deeper as it fills with water.

• It will become less deep as the rim erodes.

• It will rise up like a volcanic crater

• It will widen as it fills with lava.

The photograph shows a satellite view of the desert coast of Egypt and the Red Sea. Researchers predict that in the future, the land area of point X will be reduced by erosion. Which event will cause the most weathering and erosion to the land area at point X?

• Increasing salinity of seawater near the land

• Increase rays from the sun striking the land

• Strong storm winds blowing across the land

• Solid floating in seawater depositing on the land

The satellite photo below show San Francisco, California, which has many miles of coastline and an inland bay. Which area of the coastline has most likely experienced the greatest effect of erosion from waves over hundreds of

years?

• Area N

• Area P

• Area S

• Area T

1. Sand dunes form as a result of – 

• recycling of crust at subduction zones

• freezing and throwing rock

• 1. erosion and deposition by wind.

• 1. Erosion and deposition by water. 

If contour lines are close together, then the slope is

• gentle
• steep
• flat
• going up and down

The height above sea level is called

• topographic
• contour
• elevation
• depth

It is steep on a topographic map where __________.

• lines are closest together
• a river flows into a lake
• contours bend
• contours are far apart

Determine the contour interval:

• 5 m
• 10 m
• 15 m
• 20 m

Match the topographic map to its profile.

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