Latitude and Longitude

Intro Introductory video http://videos.howstuffworks.com/hsw/8604-geography-basics-lines-of-longitude-video.htm

Using Latitude and Longitude

Location on the Earth The earth is effectively a sphere, so how do we describe where a point is on its surface? The most common way to locate points on the surface of the Earth is by standard, geographic coordinates called latitude and longitude. These coordinates values are measured in degrees, and represent angular distances calculated from the center of the Earth.

What is latitude? We can imagine the Earth as a sphere, with an axis around which it spins. The ends of the axis are the North and South Poles. All lines of latitude are parallel to the Equator, and they are sometimes referred to as parallels. Parallels are equally spaced. Latitude lines run east and west around the globe. The equator is the starting point for measuring latitude. There are 90 degrees of latitude going north from the Equator, and the North Pole is at 90 degrees N. There are 90 degrees to the south of the Equator, and the South Pole is at 90 degrees S. Therefore, lines of latitude are always read in north or south degrees.

What is longitude? Lines of longitude, called meridians, run perpendicular to lines of latitude, and all pass through both poles. longitude values are indicate the angular distance between the Prime Meridian and points east or west of it on the surface of the Earth The Earth is divided equally into 360 degrees of longitude. There are 180 degrees of longitude to the east of the Prime Meridian; when the directional designator is omitted these longitudes are given positive values. There are also 180 degrees of longitude to the west of the Prime Meridian. Therefore lines of longitude are read in degrees of either west or east

How precise can we be with latitude and longitude?

Steps to Find a Location Begin at the point where the prime meridian and equator intersect Move north (up) or south (down) the indicated number of degrees From that point while still on the prime meridian, move west (left) or east (right) the correct number of degrees

The Equator The line which encircles the Earth at an Equal distance from the North and South Poles. The equator is located at zero degrees latitude. The equator runs through Indonesia, Ecuador, northern Brazil, the Democratic Republic of the Congo, and Kenya, among other countries. It is 24,901.55 miles (40,075.16 kilometers) long. The equator divides the planet into the Northern and Southern Hemispheres.

Prime Meridian The Prime Meridian is the meridian (line of longitude) at which longitude is defined to be 0°. By international convention, the modern Prime Meridian is one passing through Greenwich, London, United Kingdom.

Tropics of Cancer & Capricorn The Tropic of Capricorn lies at 23.5° South of the equator and runs through Australia, Chile, southern Brazil (Brazil is the only country that passes through both the equator and a tropic), and northern South Africa The Tropic of Cancer is located at 23.5° North of the equator and runs through Mexico, the Bahamas, Egypt, Saudi Arabia, India, and southern China

Circles to Remember The Arctic Circle is also the name given the region around the North Pole. It includes the Arctic Ocean, thousands of islands, and the northern parts of Europe, Asia, and North America, including the Arctic and Subarctic regions of Alaska, Canada, Greenland, Iceland, Scandinavia, Siberia and the Russian Far East. The Antarctic Circle is the region in the Southern Hemisphere surrounding the South Pole. The nearest neighbouring country is Argentina and the second nearest is New Zealand. The Antarctic Circle is the coldest and driest place on earth and is owned by no one but claimed by many, and hence it's political future is in question. .

Flash Animation http://olc.spsd.sk.ca/DE/k9mod/Mapskill/mod3fl5.swf