Create your own topographic map!

Materials Needed:

• An orange or fist-sized rock.

• Baking dish

• Permanent marker

• Water

• Ruler

Get Started:

• Put the orange in the pan.
• Pour in 1/2 inch of water, but not directly on top of the orange.
• Draw a line all the way around where the orange meets the water and air.
• Continue to add water in 1/2 inch increments and draw lines.
• Remove the orange from the water and be careful not to smudge the lines.

What does this mean?

• You can transfer the lines on your orange onto a sheet of paper. If you used an orange, it probably looks like a bullseye.
• What do you think it would look like if you used a banana or a toy truck?
• Geologists create topographic contour maps the same way. They make maps of mountains, lakes, valleys, and even cities on flat sheets of paper. Then other people can read the maps and understand where hills and valleys are.
• You can contact the USGS (United States Geological Survey) to obtain a topographic map of where you live.