John McPhee's 1993 Assembling California is delightful in many places, as the author delves into the deep geologic history of western North America. Alas, however, the book too often emulates continental drift in its inexorable progress: it's slow. Large sections resemble research notes which could have been sliced by an editor's blue pencil, or maybe subducted and recycled in a later era.

Nonetheless, McPhee is a brilliant writer and as always his genius does sparkle often enough to make Assembling California worthwhile. A few examples:

page 36

I remarked that geologists are like dermatologists: they study, for the most part, the outermost two per cent of the earth. They crawl around like fleas on the world's tough hide, exploring every wrinkle and crease, and try to figure out what makes the animal move.

pages 213-4

While India was closing with Tibet, it buckled the intervening shelf, raising from the sea a slab of rock more than a mile thick which consisted almost entirely of the disintegrated shells of marine creatures. From the depths of lithification to the rock's present loft, it has been driven upward at least fifty thousand feet. This one fact — as I noted some years ago — is a treatise in itself on the movements of the surface of the earth. If by some fiat I had to restrict all this writing to one sentence, this is still the one I would choose: The summit of Mt. Everest is marine limestone.

pages 248-9

Kerry Sieh, a San Andreas specialist at Caltech, has dug trenches in numerous places across the fault zone near Los Angeles in order to examine the evidence in the exposed sediments. He has established that twelve great events have occurred on the south-central San Andreas Fault in the past two millennia, with intervals averaging a hundred and forty-five years. The Tejon event of January 9, 1857, is the most recent. One does not have to go to Caltech to add a hundred and forty-five to that.

page 279, quoting from a 1983 paper by Leonardo Seeber titled "Large Scale Thin-Skin Tectonics"

"Our direct view of geologic phenomena has been severely limited by the relatively short span of history and by the relatively small vertical extent of outcrops. ... In many respects we only have a two-dimensional snapshot view of the geologic process. Moreover, the interpretation of geologic data was probably influenced by the psychologic need to view the earth as a stable environment. Manifestations of current tectonism were often perceived as the last gasps of a geologically active past. Thus, subjected to the principle of least astonishment, geologic science has always tended to adopt the most static interpretation allowed by the data."

pages 283-4

... Richter was a professor at Caltech. His scale, devised in the nineteen-thirties, is understood by professors at Caltech and a percentage of the rest of the population too small to be expressible as a number. Another professor at Caltech in Richter's time — and someone who manifestly understood the principles involved — was Beno Gutenberg, who provided the data from which the scale was made. The data applied only to southern California; subsequently, Gutenberg and Richter jointly developed the worldwide scale. Gutenberg did not see or hear well and was understandably reluctant to deal with reporters. He generally asked his young colleague Charles F. Richter to explain the scale to them. Since I have no idea how the scale works, let me say only that it is a mathematically derived combination of three scales parallel to one another: a magnitude scale flanked by scales of amplitude and distance. (Amplitude is the height of the mark an earthquake produces on a seismogram.) Where a line drawn between amplitude and distance crosses the central scale, it registers magnitude. With each rising integer on the magnitude scale, an earthquake's waves have ten times as much amplitude and thirty times as much energy. Richter always insisted that it was the Gutenberg-Richter scale.

(cf. SenseOfWhereYouAre (4 Jun 1999), InvisibleWriting (16 Dec 1999), DefensiveQuestions (12 May 2000), WorldTradeCenter (11 Sep 2001), IndianRiver (30 Jul 2004), MardiGras (5 Oct 2005), RansomOfRussianArt (26 Apr 2006), ... )

TopicScience - TopicLiterature - 2007-05-30

(correlates: FinalLesson, John McPhee, Comments on YouAreBetter, ...)