North America is a continent in the Earth's northern hemisphere and almost fully in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the south and west by the North Pacific Ocean; South America lies to the southeast. It covers an area of about 24,480,000 km² (9,450,000 sq mi), or about 4.8 percent of the planet's surface. As of July 2002, its population was estimated at more than 514,000,000. It is the third-largest continent in area, after Asia and Africa, and is fourth in population after Asia, Africa, and Europe.