The Science of Underground and Underwater Rivers (The Science of Everything)
Reseña del libro "The Science of Underground and Underwater Rivers (The Science of Everything)"
There is something deeply suspicious about a river that refuses to stay where we can see it. Ordinary rivers behave themselves reasonably well. They run downhill, appear on maps, attract bridges, flood somebody's basement every few decades, and generally make their whereabouts known. Underground rivers have rejected this arrangement entirely. They disappear into holes, flow beneath towns, emerge from cliffs several miles away, change directions through fractures nobody knew existed, and occasionally carry someone's fluorescent dye experiment into a spring with surprising speed. Underwater rivers are even less cooperative because once a body of water is already underwater, calling another body of water a river sounds like something invented after a very long lunch. Nevertheless, nature has managed to produce flows beneath both land and sea that behave enough like rivers to justify taking the idea seriously. The first job of this book will therefore be to separate the genuine science from the irresistible mythology. Contrary to the picture many people carry in their heads, the ground beneath us is generally not a giant system of hollow caverns containing Mississippi-sized rivers. Most groundwater occupies pores, cracks, fractures, and interconnected openings in soil and rock. It may move slowly enough that describing it as a river would be like describing a crowded supermarket checkout line as NASCAR. In certain geological settings, however, particularly limestone and other soluble rocks, those little openings become larger. Water dissolves rock, fractures widen, passages connect, caves form, surface streams vanish underground, and eventually a substantial amount of water may travel through conduits and cave passages that unquestionably resemble streams and rivers. Entire landscapes known as karst terrain can operate as three-dimensional plumbing systems in which surface water and groundwater repeatedly exchange places.
