LATITUDE AND LONGITUDE

How do we find places on maps?

The earth has a grid system for locating the addresses of cities around the world.

The “streets” running east-west are called lines oflatitude, or parallels, and the “streets” running north-south are called lines of longitude, or meridians.

These are imaginary lines.

Latitude

The Equator divides the Earth into the Northern Hemisphere and the Southern Hemisphere.

http://nationalatlas.gov/articles/mapping/IMAGES/latlong2.gif

Latitude Latitude is defined as

imaginary lines that run east to west above (or below) the equator.

The zero line for latitude is the equator which circles the earth midway between the poles.

The equator is at 0° and the poles are at 90°.

http://webhelp.esri.com/arcgisdesktop/9.2/published_images/LatLong%20from%20Globe%20Center.gif

Latitude If the location point

is north of the equator an N is added to the degrees.

If the point is to the south of the equator an S is added to the degree.

52°N

24°S

Latitude On the earth, lines of latitude are

parallel lines.

http://www.lakelandsd.com/tutorial/latitude2.jpg

Longitude The Prime Meridian

divides the Earth into the Western Hemisphere and the Eastern Hemisphere.

Hemisphere is half of the earth, hemi meaning half and sphere meaning circle.

http://www.arcticice.org/images/long.gif

Longitude Longitude is

defined as imaginary lines that run north to south

The zero line for longitude is the prime meridian which runs from the north pole to the south pole.

The Prime Meridian is at 0° .

Prime Meridian 0°

Longitude If the point is

located to the west of the Prime Meridian we add a W to the value.

If the point is located east of the Prime Meridian we add an E after the value.

30°W

80°E

Longitude On the Earth, lines of

longitude are called meridians.

The Prime Meridian has a value of 0° and no E or W. The longitude values increase up to 180° in both directions.

The International Date Line is opposite the prime meridian and has a value of 180° and no E or W. http://www.lakelandsd.com/tutorial/latitude2.jpg

International Date Line 180°

• The Prime Meridian passes through the Royal Observatory in Greenwich, England.• The International Date Line passes through the Pacific Ocean

Note: Longitude lines ARE NOT parallel because they all run through the North and South Poles.

To find a location on the earth, we use coordinates

Latitude is written first and longitude is written last.

For example, the location of Honolulu, Hawaii on a map is 21°N , 157° W

21°N is the coordinate representing LATITUDE.

157° W is the coordinate representing LONGITUDE

Using an Atlas, find the approximate coordinates of:

Tokyo, Japan

Paris, France

San Francisco, CA

Sydney, Australia

35°N, 139°E

48°N, 2°E

37°N, 122°W

33°S, 151°E

Geography Vocabulary Review Which imaginary lines run parallel?

Lines of Latitude

Geography Vocabulary Review Which imaginary lines run through the

North and South Poles?

Lines of Longitude

Geography Vocabulary Review Which geography vocabulary word

means “ half circle”?

hemishpere

Geography Vocabulary Review What is the zero line for latitude?

equator

Geography Vocabulary Review What is the zero line for longitude?

Prime Meridian

Geography Vocabulary Review What degree is the International Date

Line?

180°

Longitude and Time If you place meridians 15° apart starting with the

Prime Meridian, you will divide the Earth into 24 zones. These correspond to the 24 hours in a day.

http://www.mapsofworld.com/time-zone-map/maps/world-time-zone.jpg

Longitude and Time As you travel around the world to the east,

you gain an hour in time for each zone you cross. If you travel to the west you lose an hour.

http://www.astro.ufl.edu/~oliver/ast3722/lectures/CoordsNtime/timezon2.gif

But… If you traveled around the world to the

east fast enough you would be a day older in a short time!

If you traveled west you could go back in the past!

To solve this problem it was agreed that the 180° meridian would signal the change of date point.

Travel east and the date goes back one day; travel west and you advance a day when crossing this meridian.

But… To keep all of a

country in the same time zone, the International Date Line does not follow the 180° meridian exactly.

Other time zones make the same accommodations for country or state boundaries.