12-1B Longitude and Latitude
What is latitude?
What is longitude?
What is the prime meridian?
Coordinate Plane
How do you locate
points on a
coordinate plane?
Points are located
using a set of
ordered points,
(x,y)
(3,4)
Coordinate System for a Sphere
A coordinate system used to locate a point on
a sphere is similar to the coordinate plane.
The system has two reference lines similar
to the x and y axes.
The equator is one of these lines.
Lines that are parallel to the equator are called
lines of latitude.
Latitude
Latitude is the distance north or south of the equator.
The equator is 0° latitude.
The North Pole is 90° north latitude (90°N).
The South Pole is 90° south latitude (90°S).
equator
Latitude
Prime Meridian
The prime meridian is a north-south reference line the runs
through England (Greenwich), continental Europe, and
West Africa.
The prime meridian marks 0° longitude.
Longitude
Longitude is the distance east or west from the prime
meridian.
Other longitude lines range from 0° to 180°, east or west.
Longitude lines are all very long.
Look at the example on Page 757
Try It:
Give the approximate latitude and longitude
of each city.
1.18°N73°E
1. Bombay, India
2. Tokyo, Japan
2.35°N,140°E
3. Sao Paulo, Brazil
3.22°S,45°W
Earth Info
The average radius of the earth is 3960 miles
and its average circumference is approximately
24.900 miles.
Times zones are based on the lines of longitude.
The earth completes one counterclockwise
rotation of 360° every 24 hours.
Each 1-hour time zone corresponds to 15° of
longitude. 360  15
24
Time Zones
Find the distance between the cities.
Los Angeles, CA at 35°N latitude and New
York, NY at 41°N latitude.
The circumference of the earth is 24.900
miles.
The difference in latitude is 41°− 35°= 6°
24,900 times 6°/360°=415 miles
Find the distance between the cities.
Buenos Aires, Brazil at 35°S latitude and Sao
Paulo, Brazil at 22°S latitude.
The circumference of the earth is 24.900
miles.
The difference in latitude is 35°− 22°= 13°
24,900 times 13°/360°= 899 miles
Find the distance between the cities.
What would you do if one of the latitudes is
north and the other is south?
Add the degrees.
What is longitude?
Longitude is the distance east or west from the
prime meridian.
What is latitude?
Latitude is the distance north or south of the
equator.
What is the prime meridian?
The prime meridian is a north-south reference line
the runs through England (Greenwich),
continental Europe, and West Africa.
Assignment 12-1B
Page 759, 1-10,
19-25