Labeled diagram of mt st helens

Topographic Maps Topography is the rise and fall of a land surface due to surface features in an area. For example, mountains, hills, and valleys are all examples of topography. Topographic maps shows the topography of an area, by showing the features (the high and low places) of a land surface. They show the shape of the land, how steep a slope is, and the elevation of the land. Elevation is how much something is above or below sea level. At sea level, the elevation is zero. Above sea level, the elevation is a positive number. Below sea level, the elevation is a negative number. A topographic map has lines that curve all over the map, trying to show you the shape of the land. These lines are called contour lines, and they connect all the places with the same elevation. Contour lines actually connect back to themselves, making circles. However, many of them will not complete their circles on one map. The elevation is labeled on the line. However, each line is not always labeled, since this would make it too difficult to read the numbers if every line had a number written on it. The contour interval is the difference in elevation between the contour lines. In other words, it is what the lines are counting by. Therefore, you can use the contour interval to determine the elevation of the line you are interested in. There are a couple “rules” you can use to help you visualize the topography in an area by using the contour lines. First, contour lines never touch or cross because it is impossible to be at two elevations for the same point on Earth. Second, the closer the contour lines are, the steeper the slope. For example, if you only went a short distance on the map and were already many feet higher, that means it is a steep area. On the contrary, the further the contour lines are apart, the shallower the slope. For example, if you had to go a long distance on the map before your elevation changed, then it is pretty flat. Closed depressions are sometimes shown by putting “tick marks” on the line to indicate that the area is going down, rather than up. However, you can also tell if an area is going up or down in elevation by paying attention to the numbers marked on the contour lines. Directions: Using your knowledge of earth science and topographic maps, answer the questions below pertaining to some simplified topographic maps. I recommend that you print these questions, fill in your answers, and then input your answers into our online class site so that you can then get credit for the laboratory exercise. 1. Describe the main feature pictured in the map below. A. a crater with a flat central region B. a mountain with a flat top C. a valley with gently sloping sides 2. A topographic map of Mt. Rainier in Washington State is shown below. What is the contour interval of the map? (Note: the elevation numbers will correspond to the contour line that horizontally meets the middle of the number. This is easily seen for the 14,000 contour line, but be careful for the 13,800 and 13,600 lines.) A. 200 ft. B. 100 ft. C. 50 ft. D. 40 ft. Questions # 3-8 refer to the map below. Stations A, B, X, and Y are locations on the map. 3. What is the contour interval of this map? A. 10 ft. B. 20 ft. C. 30 ft. D. 40 ft. 4. What is the approximate elevation of the triangulation point on the top of Rock Hill? A. 150 ft. B. 100 ft. C. 200 ft. D. 180 ft. 5. Which side of Center Hill has the steepest slope (north, south, east, or west)? A. North B. South C. East D. West 6. How much higher in elevation is point Y than point X? A.