1. How is Location Determined?
Unit 1
How is Location Determined?
How can sailors far out on the ocean determined their position so they can safely return to port? With no familiar landmarks, such as roads, cities, and geographic features, they cannot describe their location in terms of surface features the way people usually do on land. Long ago, explorers solved this problem by establishing a coordinate system that covers the whole Earth.

2. Latitude & Longitude I. Coordinate Systems
A grid in which each location has a unique designation defined by the intersection of two lines.
Example- Much of New York City has numbered avenues that run north-south and numbered streets that run east-west.
The Earth’s coordinate system is called:
Latitude & Longitude

3. A. Latitude
Horizontal lines on the Earth’s surface that measure angular distance in degrees north or south of the equator.
It varies from 0o at the equator to 90o at the poles.
Lines of equal latitude are called parallels because they run parallel to each other.
Halfway between the poles is the Equator, an imaginary line that circles the Earth and determines the Northern vs. Southern Hemisphere.

4. B. Longitude
Vertical lines on the Earth’s surface that measures angular distance east or west of the prime meridian.
Unlike latitude, there is no natural or logical place for longitude measurements to begin.
Prime Meridian is the reference line from which longitude is measured. It bisects the globe into the Eastern & Western Hemispheres.
It varies from 0o at the prime meridian to 180o near the middle of the Pacific Ocean (International Date Line).

5. Longitude Lines

6. Together this is what they look like