^BNorth and South America.^b Coloured computer model of North and South America, based on satellite data. North is at top. Water is blue, bare land is brown, vegetation is green and snow and ice are white. To the west of these continents lies the Pacific Ocean (left) and to the east lies the Atlantic Ocean (right). The Atlantic extends northwards to the Arctic (across top). The tip of Antarctica (white, bottom) can be seen lying south of the southernmost tip of South America. Ocean topography is shown in varying shades of blue.