John McPhee, my favorite technical writer

I never had specific training as a technical writer, just always wrote the documentation because nobody else wanted to. Reading widely and copiously, though, is my first recommendation for becoming a better writer, so I try to seek out the better nonfiction writers to inspire me.

There are a number of nonfiction writers whose work I enjoy and would hold up as good examples. Stephen Jay Gould in biology, Lewis Thomas in Medicine.

But John McPhee, columnist for the New Yorker, is my favorite of them all. When I was convalescing from my knee replacement last spring, I finally read his Annals of the Former World (ISBN 978-0-374-51873-8), a monster on the subject of geology.

I avoided geology in my college years. We had a choice of biology or geology, and at New Mexico Tech, the Geology Department is extremely tough, especially the undergraduate intro course. I figured if anyone could help remedy this large lacuna in my education, it'd be McPhee.

This guy has it all. The big picture. The thousand telling details. The human element and the accidents of history. But he also has a wicked gift for writing, especially explaining things in terms people can appreciate.

As I was reading Annals, one paragraph so impressed me that I had to stop and catch my breath. This is from page 121, as part of his general introduction to plate tectonics.

Almost all earthquakes are movements of the boundaries of plates—shallow earthquakes at the trailing edges, where the plates are separating and new material is coming in, shallow earthquakes along the sides, where one plate is ruggedly sliding past another (the San Andreas Fault), and earthquakes of any depth down to four hundred miles below and beyond the trenches where plates are consumed (Japan, 1923; Chile, 1960; Alaska, 1964; Mexico, 1985). A seismologist discovered that deep earthquakes under a trench had occurred on a plane that was inclined forty-five degrees into the earth. As ocean floors reach trenches and move on down into the depths to be consumed, the average angle is something like that. Take a knife and cut into an orange at forty-five degrees. To cut straight down would be to produce a straight incision in the orange. If the blade is tilted forty-five degrees, the incision becomes an arc on the surface of the orange. If the knife blade melts inside, little volcanoes will come up through the pores of the skin, and together they will form arcs, island arcs—Japan, New Zealand, the Philippines, the New Hebrides, the Lesser Antilles, the Kurils, the Aleutians.

The boldfaced part just made my jaw hit the floor. What, structurally, is he doing there? The orange is a metaphor for the Earth, yes, but then what happens? It's a knife blade, but it's also a large geological structure, and it is melting.

One of the general principles that guides my own technical writing is that some people are verbal thinkers while some are more visual in their thinking, so pictures are a Good Thing. But here, McPhee doesn't need a picture; his words paint a clear picture that anyone can appreciate and visualize why island arcs form. A two-dimensional picture wouldn't work anyway. Better to let the reader use their three-dimensional imagination.