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Map Mysteries

Topics: Map interpretation, map reading, understanding humans and the landscape, landforms, earthquake and fault line relationships, topographic map interpretation, contour lines, orthophotomaps, urban landscape features, mountain landforms

Length: Varies

Type of Resource Being Described: Hands on Activity, Complete Teaching Module

Introduction:

"Map Mysteries" uses topographic and thematic maps as starting points to learn about the cultural and physical geography of the Earth. The USGS has published over 75,000 of these maps (actually, the number is more like 250,000). Think about each of these maps as a ready-to-go lesson plan with mysteries to uncover about that corner of the planet and the people who live there. Each suggested exercise includes a different map and associated in-depth questions to get students thinking about what is represented on the map, describe various features of the map, and determine conclusions about what they see. Most exercises are geared towards high school and college level classes.
 

Objectives:

To teach students about the various topographic and thematic maps produced by the USGS and the relative information each map holds.

Instructions:

Use the maps and questions below as starting points to learn about the cultural and physical geography of the Earth.

To obtain USGS Topographic Maps: Download free, digital topographic maps in a georeferenced pdf format through the USGS Store (Click on "Map Locator & Downloader"). Order paper copies of the maps from the same site. Choose up-to-date, computer-generated "US Topo" maps or hand-generated Historical topographic maps, which were produced untill about 1992. The US Topo maps have individual layers that can be turned on and off plus free analytical tools, but the historical maps, which were optimized for readability, might be easier for students to work with.

To obtain USGS Thematic Maps: Go to the USGS Store and click on "Education Products" to browse thematic maps that are popular with educators. Many of the thematic maps in the USGS Store have a link to the map's citation in the USGS Publications Warehouse. Follow that link to download a free PDF file of the map. Some maps in the USGS Store have direct links to a free PDF. Order paper copies of the maps through the USGS Store.

For assistance, call 1-888-ASK-USGS (1-888-275-8747). Go to our Contact USGS page to request information or to initiate a live chat.

Teacher discounts are available for paper maps. Products in pdf format require Adobe Acrobat Reader

Landforms Map of the Conterminous United States

  • Free Digital Download | Purchase Paper Copy
  • Into how many geomorphic regions would you divide the USA?
  • Examine the differences between the flooded river valley east coast versus the tectonic-shaped west coast.
  • Use this map to identify effects of glaciation, particularly Coteau de Prairies in South Dakota and the Driftless Area in southwest Wisconsin and northeast Iowa.
  • Examine the extent of Mississippi floodplain and Nebraska sandhills.
  • Is the Great Plains a uniformly flat landscape? Where is the flattest landscape? (The flattest landscapes are in the Mississippi floodplain and the Llano Estacado.)
  • Examine crustal deformation near the plate boundary in California.
  • Investigate the northwest-trending lineaments in Oklahoma and Texas.
  • Study the east-northeast-trending lineament from Los Angeles to the Grand Canyon.
  • Discuss the vast extent of basin-and-range province from Texas to Oregon.

Earthquakes and Faults in the San Francisco Bay Area (1970-2003)

  • Free Digital Download | Purchase Paper Copy
  • Identify rainfall patterns (mountains receive more) and infer the climate of this region.
  • Why do earthquake epicenters form linear features?
  • Which fault was more active during this period of time?
  • Where are the largest population centers? Why are they in those locations?
  • What natural hazards other than earthquakes might impact this area?

Callaway NW, Nebraska 1:24,000-scale Topographic Map

  • Go to Map Locator and Downloader and search "Callaway NW"
  • What do you think the white spot is in the north central part of this map?
  • If you thought the spot was a crater, what would you do next?—> Investigate! Map inquiry fosters and goes hand-in-hand with field work.
  • The impact crater, despite the fact that the map was made in 1951, was not noticed. In 1991, a professor at the University of Kansas began to ask questions about this spot. He conducted several field investigations with his students. While some are convinced that this is a crater, others are not. Undiscovered mysteries about our planet exist that can be examined with the help of maps!
  • Does the amount of relief of this landscape challenge your stereotype of the Nebraska landscape?
  • Do you think much has changed since 1951 in this area? Actually, more than you might expect! There was a great deal more tree cover in 1997. Why? This shows that even areas with a decreasing population can change physically.

Earthquake Lake, Montana-Idaho 1:24,000-scale Topographic Map

  • Go to Map Locator and Downloader and search "Earthquake Lake"
  • Clues as to how an earthquake caused Earthquake Lake and the date of this event are shown by the cultural and physical features on the map.
  • How did Earthquake Lake form? Cultural names reveal much about the physical and cultural history and characteristics of an area.
  • Discuss and use the Geographic Names Information System. For example, if you found a Disappointment Hill, investigate who was disappointed, why, and when.
  • Here, refer to USGS natural hazards posters to illustrate that a crack in the Earth is never as wide as the lake shown here. Therefore, the ground ruptures were not as wide as the lake. There has to be another explanation!
  • Discuss what happens when water running (in a gutter, for example) is dammed or blocked. What could have dammed Madison River to form the lake?
  • Refer to the "slide area" on the map. What kind of slide could it be? Why could it not have been a snowslide? Describe the slopes of the mountainsides near Earthquake Lake and draw profiles of it.
  • What are the clues as to when the slide took place? Clues are existence of memorial, and the lack of vegetation on the south side of the lake.
  • Who would likely be at the bottom of the canyon? Who lives and travels to this area, and why? Refer to Hebgen Lake earthquake professional paper and USGS web sites on the earthquake for photographs and eyewitness accounts.

Ocean City, Maryland 1:24,000-scale Topographic Map

  • Go to Map Locator and Downloader and search "Ocean City".
  • Why is Assateague Island (the southern island) offset from Fenwick Island (the northern island)? In other words, why are they not in a line due north and south from each other?
  • Calculate the rate of offset per year since the mid 1840s, when the two islands were aligned.
  • Discuss the cultural and natural pressures on seacoasts, including longshore current, sand migration, jetties, land use, and tourism. Refer to USGS Circular 1075: Coasts in Crisis.

South Pass, Louisiana 1:24,000-scale Orthophotomap

  • Go to Map Locator and Downloader and search "south pass".
  • Discuss the differences between looking at the Mississippi Delta at small and large scales.
  • How can people access this area? (by helicopter only)
  • What are the economic activities here (on map: oil field)? What else? (fishing, boat tours).
  • What sediment type is here? Why are there no rocks in this area? Discuss the mechanics of sediment transport by rivers.
  • Compare this map to a USGS topographic map of Lake Itasca, Minnesota (Mississippi headwaters), and a map of Dubuque, Iowa. What are the differences in landforms between each region? What is the gradient of the river in each map, and why do the differences exist?

New Orleans W, Louisiana 1:24,000-scale

  • Go to the Map Locator and Downloader and search "New Orleans W".
  • Why is most of New Orleans below sea level? Discuss how humans have impacted the environment.
  • Why were the artificial levees constructed? Discuss the differences between natural and artificial levees.
  • Why is New Orleans located where it is? Use smaller scale maps (1:100,000 and 1:250,000-scale) in conjunction with this one to discuss the terms "site" vs "situation."
  • What would be the most common natural hazard posed to this area? What would be the effect of a hurricane in this area? After a flood, how much of the area would be under water if all the levees were ruptured? Show before-and-after Hurricane Katrina photographs. Discuss what areas of the city became flooded. Does the actual flooding that occurred agree with your assessment of what would be flooded based on your analysis of the topographic maps?

Isolation Peak, CO 1:24,000-scale

  • Go to the Map Locator and Downloader and search "Isolation Peak".
  • How can weather and weather-related effects on the landscape be understood from topographic maps?
  • Discuss location and size of glaciers on the Continental Divide.
  • Why are they all on the northeast side of the divide?
  • Discuss the angle of sun and the direction of prevailing winds.
  • What influence does snowpack have on vegetation?
  • What is orographic precipitation?
  • What kind of precipitation is most common here?
  • Discuss the effects of glaciers in the past, evident on valley sizes, valley shapes, moraines, marshes, and drainage.

South Florida Satellite Image Map

  • Free Digital Download | Purchase Paper Copy
  • Discuss the human and natural threats that exist to the Everglades.
  • Discuss how agriculture and urbanization pressures are evident on this map.
  • Discuss terrain, vegetation, and settlement patterns.
  • What can be inferred about Florida's climate from this map?

Integrating the Geography Standards in Teaching With Topographic Maps

The World in Spatial Terms (Location):
Spatial information tells about where things are, and about where things are in relation to each other. Different scales of USGS maps can be used to illustrate these concepts.

Places and Regions (Physical and Human Characteristics):
The description of a place includes its physical and human characteristics. This can be illustrated with topographic maps and regions of the United States can be compared with maps. Obtain Department of Defense maps from the USGS and compare regions across the world.

Physical Systems (Land, Air, Water, and Living Things):
Physical processes constantly change the Earth's surface. Physical processes also interact with living things, creating and modifying Earth's ecosystems. Weather systems, ocean currents, volcanic activity, and tectonic plate movement affect the landscape and the organisms within it. At the same time, living things release and absorb gases, build and use soil, break down rocks, dam streams, and fill in lakes.

These and many more activities make up the systems that shape Earth's geography. USGS geologic, hydrologic, natural hazards, coal, oil, gravity, geomagnetic, historical, and topographic maps can be used to illustrate these physical systems. Digital USGS data can be loaded in a Geographic Information System to illustrate these concepts, with the use of digital vector and raster files.

Human Systems (Population, Culture, and Interdependence):
Human activities shape Earth's surface. Human settlements and structures are also part of Earth's surface. When people move from one place to another they often change the landscape as they go. In addition, people in different cultures interact with their environment in different ways. USGS geologic, hydrologic, natural hazards, coal, oil, gravity, geomagnetic, historical, and topographic maps can be used to illustrate human systems. What are the dominant economic activities for the people who live in the area you have chosen to study with your maps?

Environment and Society (Human-Environmental Interactions):
Human activities change the physical environment and ecosystems. In addition, human activities are influenced by the environment and by Earth's physical processes. Thus the interactions between people and the environment occur whenever physical systems and human systems meet -- which is all of the time! USGS maps can be used to illustrate the affect of humans on their environment, and the affect of the environment on human settlement.

The Uses of Geography (Changes Over Time):
Knowing about geography helps people understand the relationships between people, places, and environments over time. Thinking geographically allows us to interpret the past, understand the present, and plan for the future. Geography gives us a "big picture" of humans' place on Earth. Illustrate this with historical editions of USGS maps, comparing them to the latest topographic edition, and discuss the extent to which the area has changed, why the area has changed, and if the changes are increasing or decreasing.

General Questions To Pose While Exploring Topographic Maps

  • In what part of the USA is the area depicted on the map located?
  • In which state is this map located?
  • In what part of the state is this map located?
  • What is the latitude and longitude of the southeast corner of the map?
  • What is the distance, in kilometers and miles, from east to west across the map?
  • What is the distance, in kilometers and miles, from east to west across the map?
  • What is the largest town on the map? Estimate its population.
  • Describe the reasons behind your population estimate.
  • What is the nature of the topography in this area? Flat? Rolling? Sharp? Mixed? Other?
  • Given what you know about the state, is the topography of this area what you expected? Why or why not?
  • What is the range of elevation in this area? (Highest and lowest points)
  • Is the elevation in feet or meters?
  • What is the average elevation in this area? Does the highest point on the map have a name? What is it?
  • Which direction(s) do the rivers flow in this area? Why?
  • Describe the climate of this area. Include a description of the winds, sunshine, rainfall, and snowfall. What physical and cultural (human-made) map features give clues about the climate?
  • Is this area subject to a natural hazard? If so, what would be the most likely natural hazards to pose a threat to this area?
  • Is the threat of these natural hazards high, moderate, or low? Take into account the location of the area and the physical features found there.
  • What is the nature of the settlement pattern in this area? Is it concentrated, linear, or diffuse?
  • What topographic, climatic, hazard-related, or other constraints affect the settlement pattern?
  • What are the things that people do in this area for work? What kind of jobs do they have?
  • What is the most common occupation found here?
  • What is the predominant economic activity in this area, and what map features give clues about this activity?
  • What physical and cultural (human-made) map features give clues about what people do in this area for work?
  • What are the things that people do in this area for recreation?
  • What is the most common recreational activity in this area?
  • What physical and cultural (human-made) map features give clues about what people do in this area for fun and recreation?