Continental Divide

Let's talk a little geography shall we? Geography was always one of my favorite subjects in grammar school. Continental divides, latitudes, longitudes, Tropics of Capricorn and Cancer, Tierra del Fuego and the Arctic Circle, states and capitals, elevation, rivers, tributaries, etc. I was a mental explorer long before I ever set out on foot.

Today we hiked in the Witwatersrand National Botanical Gardens and found out that Johannesburg, as well as the entire province of Gauteng where the city is located, sits on top of  the Witwatersrand range, a large sedimentary range of rocky hills of 1700 to 1800 meters above sea level. The Witwatersrand range forms a continental divide, an imaginary line which divides a land mass hydrologically and determines which way the rivers drain. Rivers to the north of the Witwatersrand such as the Crocodile River drains into the Limpopo River and Indian Ocean and  the run-off to the south drains into the Orange River and Atlantic Ocean.

Wyoming

What seemed odd to me about the Witwatersrand divide is that it runs east to west. I am more familiar with the Great Western Continental Divide of North and South America which runs north to south down the ridge of the Rocky Mountains into the Andes. We have visited high points in a number of US National Parks along the Rocky Mountains in Montana's Glacier, Wyoming's Yellowstone and Colorado's Rocky Mountain NPs. The Great Western Divide delineates whether a river runs into the Pacific (west) or Atlantic Ocean (east). That made more geographic sense to me.


I decided to do a little reading on the subject and found out that in addition to the Great Divide, the United States also has a series of east-west divides delineating run-off to Canada's Hudson Bay and Arctic Ocean to the north and the Gulf of Mexico and Atlantic to the south.

So it is the same with Africa.  The Witwatersrand is one of several divides throughout this massive continent, the most significant probably being the Congo-Nile Divide between the watersheds of the Nile which flows northward to the Mediterranean Sea and the Congo flowing south to the Atlantic Ocean.

But even though I must have failed the quiz about the USA east-west divides in grade school, I still maintain that I know the geography of North America pretty well. After Geography stopped being a core subject in school, I continued my studies on the ground. I have visited almost every state in the USA - except for Arkansas and Oklahoma - and most of the provinces of Canada.

Visits to National Parks have definitely been a big part of my geographic learning experience. We've been to hundreds of parks and preserves and in addition to the continental divide, we saw many of the unique geological features I had studied in books up close and personal on the ground there. From the Grand Tetons and the Great Smoky Mountains to the Mammoth Caves and Carlsbad Caverns, the Everglades and Congaree swamps to the Saguaro and Painted deserts, the Grand and Bryce Canyons to the Badlands and Tallgrass Prairies, the Katmai Peninsula, Channel and Virgin Islands to the Glacier and Biscayne Bays, the Mount Rainier, Haleakala and Hawaii Volcanoes to the Cuyahoga and Death Valleys, and from Meteor Crater to Crater Lake. It is a great way to learn your Geography lessons.

So now that I have moved to a new continent I have added Geography back into my curricula. I will read about the unique geological features of Africa for sure and study the maps and globes but I still plan to do most of my learning on the ground. It is just more fun that way!