Presentation on theme: "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."— Presentation transcript:
The earth has a grid system for locating the addresses of cities around the world. The “streets” running east-west are called lines of latitude, or parallels, and the “streets” running north- south are called lines of longitude, or meridians. These are imaginary lines.
The Equator divides the Earth into the Northern Hemisphere and the Southern Hemisphere. http://nationalatlas.gov/articles/mapping/IMAGES/latlong2.gif
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
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
On the earth, lines of latitude are parallel lines. http://www.lakelandsd.com/tutorial/latitude2.jpg
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 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°.
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
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
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.
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
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
Which imaginary lines run parallel? Lines of Latitude
Which imaginary lines run through the North and South Poles? Lines of Longitude
Which geography vocabulary word means “ half circle”? hemishpere
What is the zero line for latitude? equator
What is the zero line for longitude? Prime Meridian
What degree is the International Date Line? 180°
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
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
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.
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.