Short Tectonic Plates Quotes

As we sit here, continents are adrift, like leaves on a pond. GPS tracking shows North America & Europe currently moving apart at the same rate your fingernail grows, or about two yards in a human lifetime.

published in 1980, John McPhee noted that even then one American geologist in eight still didn’t believe in plate tectonics. Today

It would be hard to believe that the continuous movement of tectonic plates has no effect on the development of life on earth.

Apart from much else, our lively interior created the outgassing that helped to build an atmosphere and provided us with the magnetic field that shields us from cosmic radiation. It also gave us plate tectonics, which continually renews and rumples the surface. If Earth were perfectly smooth, it would be covered everywhere with water to a depth of four kilometers. There might be life in that lonesome ocean, but there certainly wouldn’t be baseball.

Each scenario is about fifteen million years into the future, and each assumes that the Pacific Plate will continue to move northwest at about 2.0 inches per year relative to the interior of North America. In scenario 1, the San Andreas fault is the sole locus of motion. Baja California and coastal California shear away from the rest of the continent to form a long, skinny island. A short ferry ride across the San Andreas Strait connects LA to San Francisco. In scenario 2, all of California west of the Sierra Nevada, together with Baja California, shears away to the northwest. The Gulf of California becomes the Reno Sea, which divides California from Nevada. The scene is reminiscent of how the Arabian Peninsula split from Africa to open the Red Sea some 5 million years ago. In scenario 3, central Nevada splits open through the middle of the Basin and Range province. The widening Gulf of Nevada divides the continent form a large island composed of Washington, Oregon, California, Baja California, and western Nevada. The scene is akin to Madagascar’s origin when it split form eastern Africa to open the Mozambique Channel.

…when something seems complicated, we do not understand it, but when we do understand something, it has become simple.

A good short history of the development of the drift hypothesis and the final emergence of plate tectonics is given in A. Hallam, A Revolution in the Earth Sciences: From Continental Drift to Plate Tectonics (Oxford: Clarendon Press, 1973)

For many geologists, the most important consequence of the recognition of plate tectonics was that it brought confirmation of continental drift. As important, plate tectonics allowed continental drift to be determined with considerable precision. This became immediately clear to Clark Burchfiel, now at Massachusetts Institute of Technology (MIT), who in 1968 had carried out fieldwork in Yugoslavia, and returned home to discover Le Pichon’s paper. By knowing the relative motions between Africa and North America and between Europe and North America, Le Pichon had predicted the motion between Africa and Europe for the previous 80 million years, a history that included not only the present-day convergence between Africa and Europe, but also periods when these two regions moved in different directions relative to one another, including a period when they diverged from one another. This history of relative plate motion wrote a complex history on the rock record of the region affected by the relative movement of Africa and Europe. Nevertheless, Burchfiel had inferred from the geologic history of this rock the times of major changes and had inferred what tectonic processes (convergence, divergence, and directions of relative movement) might be occurring at these times. Le Pichon’s calculated plate motions, from data solely in the Atlantic Ocean, predicted many of Burchfiel’s observations and inferences. A new idea becomes believable when it predicts something that has not yet been measured or explained, especially when the idea is really trying to explain other facts.

We are witnessing a shift in the political tectonic plates throughout the whole of the Middle East and beyond into Africa, and the west’s apparently surgical involvement will probably do little more than generate some short-term satisfaction that we are doing something. It is not that I am morally squeamish about bombing IS fanatics. Rather, I think we ought to recognise that we are little more than bystanders to a war that is so much bigger than we ever imagined, and so much more complicated than the rhetoric of terrorism or limited conflict allows. Since the second world war, we have got used to the idea that big war is a thing of the past. But no more. This is the third world war. And this time we are on its fringes.