Grade 7 Science: Locating Places - Latitude, Longitude, Equator, Prime Meridian

Latitude and Longitude

• The line of 0° latitude is called the Equator.

Location Identification

• If you are located at 45° North and 90° West, you are in North America.

Longitude Measurement

• Longitude is measured from the Prime Meridian, which passes through Greenwich, England.

International Date Line

• The International Date Line is an imaginary line that runs roughly north-south through the middle of the Pacific Ocean, roughly following the 180° meridian.
• It separates two consecutive calendar days, with locations to the west of the line being one day ahead of locations to the east.

Crossing the International Date Line

• If a ship crosses the International Date Line from east to west, it jumps forward one calendar day.

Prime Meridian and International Date Line

• The Prime Meridian is significant in relation to the International Date Line because it is the reference point for measuring longitude, and the International Date Line is roughly the antimeridian of the Prime Meridian.

Traveling Across the International Date Line

• When travelers move from west to east across the International Date Line, they effectively "lose" a day, as they move back in time by one calendar day.

The Prime Meridian

• The Prime Meridian is an imaginary line that runs through Greenwich, England, and is designated as 0° longitude.

Latitude Measurement

• Latitude is measured in degrees north or south of the Equator, ranging from 0° at the Equator to 90° at the North or South Pole.

Significance of the Prime Meridian

• The Prime Meridian serves as the reference point for measuring longitude, allowing locations to be precisely identified and navigated.