Karen Rupert, age 9, Houston, Tex., for her question:

Do all continents have a continental divide?

The greatest American adventure is a family auto trip from coast to coast.  Somewhere in the regions of the western mountains we cross a line.  WE would never notice it, but usually there is a sign beside the road, which tells us we are crossing the Great Divide.  This is our proud name for the continental divide of North America.  All the other wide landmasses of the earth have their continental divides.

The rivers of a vast land mass run dawn, down from the high ground to the lowlands. Finally they reach the Sea , which is lower than any of the land, and there they Empty their fresh waters into the salty oceans. Some rivers run into inland lakes, and the lakes spill over with streams and waterfalls. Most of this lake born streams loin the rivers and sweep along to the Sea.

A few rivers spill into deep inland lakes and never get to the ocean.  The Jordan River of Utah empties into the Great Salt Lake, which is shut off frown the sea.  But most of the world's river water flows down, downhill to the salty ocean.  It may gush down a steep slope at 20 Miles a hour  which is four times faster than you can walk.  It may crawl over a gentle Slope and take more than three hours to travel a lazy mile.

But the path of a river must run down a slope, even when the slope is too gentle for us to notice.  This is because water on the ground must obey nature's traffic lair, which says that rivers must run downhill until they meet their own level.  This low level usually is the sea.  The solid continents are, of course, wrinkled with ups and downs, low valleys, and lofty mountains.  Even a flat flat plain in slightly tipped, and none of the continents is as flat as a tabletop.

Each continent has one ridge of high ground, which is higher than all the rest.  This is its continental divide.  A merry stream born on the very top of a continental divide may flow down this side or that side.  But the streams born on the sides of the continental divide cannot flow up one side and down the opposite side.  So a continental divide divides the rivers of a continent and makes them flow in opposite directions.  The rivers born on the Eastern side of our Great Continental Divide flow into the Atlantic or the Gulf of Mexico.  Those born on the western side flow to the Pacific Ocean or to the Gulf of California.  And Each of the Continents has its own  ridge, which divides the flowing rivers into opposite directions.

The continental divide of Entebbe sends some rivers to the Atlanta some to the Arctic, some to the Black Sea and some to the Mediterranean.  The continental divide of Asia sends some rivers to the Arctic, some to the Pacific and some to the Indian Ocean.  The continental divides of Africa sends some rivers to the Atlantic and some to the Indian Ocean.