Key Question• How do you make a topographical map from a 3-dimensional surface?

Topography and Topographical maps

• Topography is the shape of the surface of an area and includes the elevations of land formations like mountains. The topography of a region is represented by a topographic map.

• A topographic map is the two-dimensional representation of a three-dimensional land surface. Scientists use these types of maps to understand the effects of geologic processes on Earth's surface.

Topographic contour lines

• Topographic maps show the difference in elevation through the use of contours.

• Contour lines connect points of equal elevation.

• Contour lines are drawn at specific intervals known as the contour interval.

• What is the contour interval on this map?

• 10 meters

• In this investigation, you will use a model land surface to make a contour map.

Contour lines & contour intervals

Making a topographic map-Using the GeoBox

•The GeoBox has a sticker on the side. •Each mark on this sticker represents one centimeter. •Pour water into the GeoBox up to the first centimeter line.

•The GeoBox has a sticker on the side. •Each mark on this sticker represents one centimeter. •Pour water into the GeoBox up to the second line. This will be our zero mark

Making a topographic map-Using the GeoBox

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•Place the topo lid on the GeoBox.

•Stand over the GeoBox so that you are looking down on the topo form.

•With the overhead projector marker, outline the perimeter of the land surface onto the lid.

•This will be considered “sea level,” or the 0 meter contour line.

Uncovered land surface

Water covering land surface

Sea level(coastline)

•Label the 0 cm line

•Now, using your marker, number each centimeter above sea level.

•Remove the topo lid and add water until the water level reaches the 1-centimeter mark.

•Replace the lid. Trace the “coastline,” the line along which the water and land meet, onto the lid.

•All points on this line are 1 cm above sea level. They form a contour line, a line of equal elevation.

•Replace the lid. Trace the “coastline,” the line along which the water and land meet, onto the lid.

•All points on this line are 1 cm above sea level. They form a contour line, a line of equal elevation.

•Label the 1 cm contour line

•Add water to the level of the 2 centimeter mark.

•Add water to the level of the 2 centimeter mark.

•Replace the lid and again, trace and label the “coastline.”

•All points on this line are 2 centimeters above sea level.

•Continue this procedure until the topo form is covered with water.

•Now you have a contour map of your land surface.

The elevation for each contour represents 100 meters.

•Use the tracing paper to trace what is on the lid. Each partner makes his/her own contour map.

•Now you have a contour map of your land surface.

Once the contour lines are present on your map, add details to show land use using standard mapping symbols.

•Put the following features on your map

•Geographic north

•A contour interval

•A geographic scale

•A verbal scale

•A numeric scale

•A river

•A depression

•An airport

Topographic contour lines

Color in areas on your map where appropriate.

• Water is shown in blue.

• Densely populated areas are shown in gray or pink.

• Wooded areas are in green and open areas in white.

• Individual buildings are solid black shapes.

• What is the direction that your river is flowing?

• What is the difference in elevation between the start and end of the river?

• What is the overall total change in elevation in your map?

• What is the highest elevation in your map?

• By looking at your map, what area is the steepest? Remember: Look at the contours to see how close or far away they are from each other.

Display the first overlay of the Topographic Maps Practice color teaching tool. Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams. Place the second overlay on the overhead. Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Display the first overlay of the Topographic Maps Practice color teaching tool. Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams. Place the second overlay on the overhead. Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Display the first overlay of the Topographic Maps Practice color teaching tool. Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams. Place the second overlay on the overhead. Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Display the first overlay of the Topographic Maps Practice color teaching tool. Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams. Place the second overlay on the overhead. Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Display the first overlay of the Topographic Maps Practice color teaching tool. Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams. Place the second overlay on the overhead. Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Engage students in a class discussion to predict what the contour diagram will be for each of the profiles shown. Students may even attempt to draw the diagrams.Were your students’ predictions correct?

Guided Practice: Topographic Mapping

Observing Convection Currents

• Place candle and incense under chimneys

• Light incense

• What happens to the smoke?

Observing Convection Currents

• Light the candle

• What happens to the smoke now that the candle is lit?

• Can you explain your observations?

How does convection affect breezes?

How does convection affect breezes?

Exploring Wave Speed

• What happens to the speed of water waves as they travel from deep water to shallow water at a beach?

• Does wave speed increase or decrease as waves move from deep water to shallow water at a beach?

Experiment!

• Fill GeoBox with water to a depth of 1 cm

• Pick up one end of box 2 to 3 cm off the table.

• Gently drop the box from this height, and time how long it takes for the wave to travel back and forth 4 times (that’s a total of 8 one-way wave trips).

• The total distance is 264 cm.• Divide by the time to get an approximate

wave speed.• Put more water in and try it again.• Does the wave speed increase or

decrease?

Wave Speed vs. Water Depth

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Water depth (cm)

Wav

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