by Donald E. McHenry
"A noble earthquake! A noble earthquake" shouted John Muir as he ran out of his cabin in Yosemite Valley very early in the morning of March 26, 1872. He felt sure he "was going to learn something. The shocks were so violent and varied, and succeeded one another so closely, that I had to balance myself in walking as if on the deck of ship among waves, and it seemed impossible that the high cliffs of the Valley could escape being shattered… It was a calm moonlight night, and no sound was heard for the first minute or so, save low, muffled, underground, bubbling rumblings, and the whisper of agitated trees, as if nature were holding her breath. Then suddenly, out of the strange silence and strange motion, there came a tremendous roar. The Eagle Rock on the south wall, about half a mile up the Valley, gave way and I saw it falling in thousands of the great boulders I had so long been studying, pouring into the Valley floor in a free curve luminous from friction, making a terribly sublime spectacle…There was no swaying, waving or swirling (of the trees) as in windstorms, but quick, quivering jerks, and at times the heavy tasseled branches moved as if they had all been pressed down against the trunk and suddenly let go, to spring up and vibrate until they came to rest again. Only the owls seemed undisturbed."
This was the Great Inyo earthquake which wrought havoc on the town of Lone Pine in the Owens Valley [and] was neither the first nor last earthquake in the Yosemite region. Such disturbances were a part of the mountain-making movement of the earth’s crust in this area and doubtlessly many were extremely violent. According to Dr. B. Gutenberg, the Inyo earthquake of 1872 had an intensity "at least equal to the 8-1/4 of the San Francisco earthquake of 1906, and probably greater."
A most curious phenomenon was the breaking up of the ice at the ice-skating rink near Camp Curry in Yosemite Valley, reducing the ice to a mass of squares, none larger than 12 inches. Noteworthy was the apparent absence of rock slides from the valley walls, certainly none like those reported by Muir in 1872.
Whether we concern ourselves with such earthquakes as described by John Muir, the less intense one of December 16, or the many minor tremors occurring over the years, all are sufficient evidence that geologic activities in the Sierra are not a thing of the past.
Reprinted from Yosemite Nature Notes, Feb. 1955