How Do Waterfalls Work?
Along with gravity, the topography has to cooperate and be made out of the right material. The ledges of waterfalls are typically formed out of bedrock that is more resistant than the rest of the stone encasing the river. Eventually though, the erosion caused by the water's action pierces through the ledge from underneath and allows the waterfall to gradually recede. In the end, what is left if anything at all from a former waterfall is smaller, gentler rapids.
The two most common forms of volcanic rock found at the earth's surface are basalt and granite. Many waterfall ledges are carved out of basalt, which is known geologically to form at ocean basins. Basalt is also fast cooling, fine grained and of a dark color.
First Hand Experience of How Waterfalls Work
Despite the sheer force of some of the world's waterfalls and the way their power, pressure per square inch and whirlpool effects present a potentially lethal threat, some daredevil humans have been tempted to experience first-hand how a waterfall works by going over one in a barrel or boat. The most famous attempts at going over a waterfall have occurred in Niagara Falls, perhaps because of the fact that it straddles the border of the U.S., the daredevil capital of the world.
The first person to conquer Niagara Falls in a barrel was a man, not a woman, a feat that should be heralded by feminists everywhere. Annie Taylor did so on October 24, 1901, but not before someone used a bicycle pump to inflate the interior pressure of the barrel to 30 PSI. There was a sad postscript to this woman's story, though. While she died in poverty ten years later instead of the fame she had anticipated, the next person to barrel down Niagara Falls, Bobby Leach, did gain notoriety.
Close to a dozen more have done this daredevil feat since, including, in 2003, a Michigan man who was the first person to experience how a waterfall works with just the clothes on his back. Worse for Kirk Jones than the $2,300 fine and banning for life from Canada was probably the fact that his inebriated friend could not figure out how to work the video camera, and thus, failed to preserve this remarkable feat for posterity.