Where are We in the World? (teacher)

map segment

Overview

Students consider the concept of location. Looking at a world map, they identify their lines (technically, angles) of latitude and longitude and use them to locate all Global Lab participants.

Objectives 

Students will:
- Use longitude and latitude to locate sites on one or more world maps;
- investigate distances to other Global lab sites and explore implications of their location

Classroom Management and Preparation

Bookmark the Global Lab Web site from which you can go to the Global Lab Map.

Bookmark http://earth.google.com

Additional Materials:

Large classrom world Map (flat or globe)
Stickers or push-pins
Small map pages for students

Time:

  One class period. Two, if it includes an introduction to Google Earth. 

Steps:

1. Warm Up

Ask your students to consider when it is important to know where they are located.  When might it be important to be exact? (Imagine you are on a boat and trying to find the island of Tahiti, the destination of some early Polynesian explorers. How could you navigate?)

2. Locating Ourselves

There are various strategies for this exercise. The shared GL step is location of your school on the web site map. This may already have been done by class time. Location on a large paper map or on individual maps is also an excellent exercise for students. Finally, using Googler Earth resources opens a gateway to rich investigations of local resources.

Computing Latitude and Longitude

1. If you do not know the latitude of your school, you can compute it. You can use a Gnomon or a clinometer. Place it on a piece of wood at local noon, making sure it is level (a marble will placed on it will not roll around). You will need to use the online table to convert the sun angle at local noon into latitude.
 
2. To compute the longitude, you need to know Greenwich Mean Time (Use map with hours to and from Greenwich Mean Time). Longitude is reported as the degrees east or west of Greenwich.  Measure the difference between your local noon and noon, according to your clock (less than a half hour). That plus a correction to Greenwich Mean Time will give you yourlongitude.  (Divide by 24 hours/day. That will tell you the fraction around the earth you are located, and multiply by 360, degrees around the earth.) This will tell you how far past Greenwich you are located.  If you are west of Greenwich, you will have a number bigger than 180. 

3. Locating Others

1. Have students locate the latitude and longitude lines (technically angles), and the coordinates of the other Global Lab sites.  (These coordinates are located on each school's web page, which you can access by clicking their map site.) Ask students to place push pin or sticker on the world map or globe locating their class and other Global Lab classes.  They should also maintain their own map page in their journal.  Remind students that as they do so, Global Lab students around the world are placing map tacks on their own maps and that, in each class, one of the map tacks is for your school. 

 
2. Ask your students to think whether there are implications of where they (and other sites) are located.  This is a topic to which you will return later.
Is your school, for example, in:
         A rural vs. an urban area? A warm or cold region?
         A coastal or inland area? An area rich in water and good soil or a more physically challenged area? 

Latitude implications:

Temperature increases towards the equator. Why? Is this enough to explain the position of deserts? Biodiversity increases towards equator. Why? Could this be connected to the increase in temperature and biota, providing more niches for plants and animals.
Length of day is completely determined by latitude. (It is the length of the day and the height of the sun that determines how much energy you get.)

Time Zones

Longitude implications:
There are time zones because as the Earth turns, sunlight falls on different parts of the globe, from East to West. When would be the best time for you to talk to someone in Italy? Someone in Singapore? Someone in San Francisco,US? Someone in Beacon, NY, US? For someone in Milan, Italy to talk to someone in Hong Kong? Consult the Russian Time Zone Site. [http://www.worldtimezone.com/]

EXTENSIONS:

Latitude and Longitude

Investigate free maps such as those available here: http://www.graphicmaps.com/webimage/testmaps/maps.htm

Take pictures of your area with various GPS apps, such as a cell phone with that capacity.

RESOURCES

Wikipedia has fine pages on the subject, including a List of Cities by Latitude.

My World GIS Pasco produces this educational GIS produced by educators at Northwestern. It sells for $99, but can be used in a 45-day trial, during which time an extensive set of data can be mapped, and layered on the world map.