the Moving Ground: Plate Tectonics and Machinery Under Your Feet

The Atlantic gets about two and a half centimeters wider every year. That is the rate a fingernail grows. Run it for two hundred million years and you have an ocean five thousand kilometers across. That is the whole difficulty with this subject. Everything the solid Earth does happens at speeds human senses register as zero, and then the totals arrive and a hemisphere has been rearranged. A century ago the man who assembled the evidence for it was dismissed by most of the geological profession, and for good reasons that turned out to be wrong. It took a world war, a submarine detection technology, and a pattern of magnetic stripes on the seafloor to settle the argument. Thirty-five chapters. No geology background required. Each one takes a single question and answers it properly, from the first glance at a world map to the parts still unexplained. - What evidence was actually assembled in 1915, and why it was rejected - How wartime sonar accidentally redrew the floor of every ocean - Why the seafloor is so much younger than the continents - The magnetic stripes, and the three people who read them correctly - What earthquakes under ocean trenches gave away - What actually pushes the plates, which is not what most people are taught - Whether you can take a scan of the mantle, and what it shows - How a continent tears open into a new ocean - Why some eruptions ooze and others take the top off a mountain - How rock stores centuries of strain and releases it in seconds - Why earthquake prediction has failed, stated precisely rather than vaguely - What can honestly be said about future shaking, and what cannot - Whether mantle plumes are real, which is a live argument - Why the Earth assembles a supercontinent every few hundred million years - How drifting plates shaped climate and the tree of life Including the questions the theory still cannot answer. Plate tectonics is the most successful idea in the history of the Earth sciences and it has holes in it. The final chapter names them, without apology and without pretending they are smaller than they are. This is the story of the machinery underneath everything, written for people who want the actual mechanism rather than a diagram and a shrug. Scroll up and start reading.