The Earth is a geological jigsaw. The episode of the History Channel's “How the Earth was Made” on Loch Ness shows that red sandstone abutting one side of the deep Scottish lake is identical to the sandstone of the Catskills. The castles on the highland precipices and the brownstones of New York are made from the same material. Over billions of years the continents have broken apart and collided; the Earth has risen and fallen and the surface has changed countless times.
The problem with the jigsaw comes when the pieces don’t fit snugly together. Native Americans and European settlers in California felt the ground shake, but not until after the disastrous 1906 San Francisco earthquake was the reason discovered. Episode one of “How the Earth was Made” shows how early 20th century geologists pieced together the clues and uncovered the San Andreas Fault, a geologically unstable line running along the California coast through San Francisco and Los Angeles. Only in the 1960s, when plate tectonics was belatedly accepted by science, was the fault explained as the line where two plates of the Earth’s crust meet, forever pushing against each other and building the pressure that finds relief in an earthquake.
The show’s stentorian narrator seems to promise a prediction of when the “big one” will come. The geologists interviewed know better because the means to predict a quake have not been developed. They can only acknowledge that a major jolt is inevitable, followed by massive destruction and loss of life. Season one of “How the Earth was Made” is out on Blu-ray.
