Geological Society of America, Adapted with permission.
You may have seen or used Global Positioning System (GPS) devices in cars or on camping trips. These devices use data from satellites orbiting the Earth to locate places on our planet. GPS devices describe the locations to us in the form of latitude and longitude coordinates.
Citizen scientists involved in the Geological Society of America's EarthCaching project (http://www.earthcache.org) use GPS technology and latitude and longitude coordinates to locate places on the Earth. This activity will help you learn how to find locations using latitude and longitude.
For a group of four:
- Orange, or other spherical object
- World map or globe
- Pencils and black marker
- Index cards
- Internet access
- Imagine that your orange is Earth. Place a mark somewhere on the orange to represent where you live. How could you communicate to someone exactly where you live? Working in a group of about four students, discuss.
- Now, look at the map or globe. Notice the lines that run horizontally and vertically across the map or globe. What do you think these lines represent? How can they help you locate places on the planet?
- Locate the lines that run across the Earth horizontally, or in the East-West direction. These are the lines of latitude. What does the line in the middle represent? What number do you see on, or next to, that line? As you move away from this line, towards the North and South pole, what happens to these numbers? Why? These numbers are the degrees of latitude. Where are the highest latitudes?
- Locate the lines that run from north to south on the map or globe. These lines are called “meridians”. Locate 0-degrees longitude. This is called the “Prime Meridian”. What is the largest number you see associated with meridians? What happens if you go past this number?
- Find where you live on the globe or map. What is the latitude there? If it's north of the equator, you read the latitude as so many degrees "north." What is the longitude? If it's west of the Prime Meridian, you read it as so many degrees "west."
- Locate the country that is 35 degrees North latitude and 25 degrees East longitude. What body of water surrounds this country? If possible, look up this country on the Internet and find out who lives there, as well as and something about the country's history and culture.
- Locate a country you would like to visit, and write down latitude and longitude within that country on an index card (don't include the name of the country). Trade your card with another person in your group, and locate that person's country. Who is able to find the other country first? Check with each other to see if you located the countries correctly. Research your country online, and trade what you find out with your partner.
- Science and engineering practices-Developing and using models
- Crosscutting Concepts-Systems and system models
- Disciplinary Core Ideas-Earth and the solar system