Earthquake Storms

by John Dvorak

  In addition to the zone of fractures and wedges and the belt of fault gouge, Noble recognized yet another key feature of the San Andreas Fault. Along the 50 miles of fault trace that he studied and mapped, he noted that “scarcely anywhere in the fault-zone are the rocks on opposite sides of the master fault similar.” The most striking contrast—and one that is easy for a nongeologist to see—is in Cajon Pass at a place known as Blue Cut.

  As the lowest gap in a very long trend of east-west mountains, Cajon Pass is the obvious place to run roadways and railway lines. Because the roadways and railway lines required a low grade, workers had to cut deep into the hillside, revealing in one stretch an astonishing blue-gray, often iridescent rock known as the Pelona schist.

  For the fast-paced traveler, the Pelona schist is best revealed in a large roadcut where I-15 runs through Cajon Pass midway between the Kenwood and Cleghorn exits. North of the roadcut the rocks are a tan sandstone. Between the schist and the sandstone runs the San Andreas Fault.

  To get a better look at the Pelona schist, one needs to travel the stretch of old Route 66—once regarded as the nation’s Mother Road—that runs through Cajon Pass. Still identified by large white stenciled shields painted on the roadway, Route 66 passes through a section known as Blue Cut where restaurants, small stores, and a few motels were once located to cater to travelers during the heyday of cross-country motoring during the 1950s. Route 66 is now all but abandoned, but here at Blue Cut one can find clear evidence of the San Andreas Fault.

  There is a large vertical cut of blue rock, the rock cut through with milky-white veins of quartz. Drive north a few hundred feet and the rocks are entirely different: a tan sandstone. Where the transition occurs is part of the San Andreas Fault.

  To be even more specific, where the fault trace runs—and to have the opportunity to stand precisely on the trace—one needs to negotiate a dirt road that runs west from Route 66. After crossing three railroad tracks, the road leads to a large parking lot. From there, a trail takes an intrepid traveler to the edge of a small lake—Lost Lake—a feature Noble knew well and described in his reports.

  This elongated lake, about 600 feet long and as much as 100 feet wide, is similar to the dozen or so ponds that Lawson and Palache found just south of Mussel Rock—and which are now either dry or filled in—and that led Lawson to conclude that the San Andreas Fault must still be active. If one walks around the south side of Lost Lake, one finds boulders and pebbles of blue Pelona schist. On the north side of the lake is the tan sandstone. The southern edge of the lake marks the fault trace.

  To get even more precise, walk to the southeast end of the lake. Here, on the surface, is a perennial mud hole stretched across the landscape and located in an arid environment. What is the source of the water? It is groundwater forced up by fault gouge. That line of mud is the San Andreas Fault.

  One can imagine Levi Noble standing here nearly a century ago. His red high-clearance low-geared Model A is parked on the dirt road. He is dressed as Sherlock Holmes, possibly, wearing his favorite yellow shirt with red polka dots. He looks around … and sees other indications of the fault.

  Far to the southeast is a notch oddly located midway on a hillside. To the northwest is Lone Pine Canyon, long and broad, similar in form to the San Andreas Valley in that Lone Pine Canyon also cuts diagonally across a mountain range. And on opposite sides of the canyon are dissimilar rocks. On the south side is the blue Pelona schist. On the north side is a variety of rock types—granites, gneisses, and even an outcrop of limestone.

  All this indicates, with great exactness, exactly where the San Andreas Fault lies amidst this diverse array of geological features. But how does it move? What is the culmination of so many earthquakes?

  This is a crucial question. And Noble had an answer.

  Early during his study of the fault, Noble was led by a Mr. Peters, whose ranch was at the base of the San Bernardino Mountains just southeast of Cajon Pass, to see a peculiar set of deep ravines. Each ravine had a right-offset dogleg. In each case the amount of offset was about 150 feet.

  Taking the 1906 earthquake as typical, when the ground surface shifted to the right about 15 feet, the doglegged offsets at the four ravines seemed to be evidence for ten earthquakes of similar size rupturing along the same fracture.

  But, as Noble had determined, the San Andreas Fault had existed and had run along the north side of the San Gabriel Mountains and through Cajon Pass at least since the Quaternary Period—that is, for millions of years. And so, somewhere, there must be evidence for many miles of horizontal movement.

  And Noble knew where it was.

  If one returns to Blue Cut and drives north a mile or so along Route 66 and across the San Andreas Fault, one will see to the west a curious outcrop of high-standing rocks. These are the Mormon Rocks, a series of hogback ridges with deep pockmarks, their unusual shape making them a favorite of movie directors who want to film Hollywood Westerns, and so named because it was here that Mormon pioneers would camp and collect water before crossing the Mojave Desert to Salt Lake City, and where they would arrive after a successful crossing of the desert and have a first chance to replenish their water supplies.

  The Mormon Rocks are a thick sequence of tightly cemented sandstone beds, a characteristic that makes them much more resistant to erosion than the surrounding gravel and silt deposits and thus allowing them to stand out in relief. As Noble knew, there was only one other exposure of similarly appearing rocks in the region—and it was within sight of his ranch, 25 miles to the northeast, at Valyermo.

  Standing at his ranch, Noble could look south through a notch in the hillsides made by Sandrock Creek at another thick sequence of sandstone beds, also tightly cemented and also with deep pockmarks and high-standing hogback ridges. These are the rocks of the Devil’s Punchbowl. And they lie immediately south of the San Andreas Fault, while the Mormon Rocks lie immediately to the north.

  The offset was in the same direction that the ground surface had shifted in 1906 and the same as the four ravines displaced at the Peters ranch north of San Bernardino: a shift to the right. Could it be that the rocks of the Devil’s Punchbowl and those of the Mormon Rocks had once been a single continuous geologic unit that had been split and slid apart by the San Andreas Fault so that they were now separated by 25 miles? The similarities were too much to be a coincidence. Noble was convinced. But was the geologic evidence strong enough to convince others?

  Though he lived away from and worked outside of established scientific institutions, Noble did correspond with other geologists, often trying to convince them to visit him at Valyermo and see the evidence. On at least one occasion, he wrote to Lawson and offered to pay his travel expenses and said the Berkeley professor could stay at the ranch house at Valyermo. Lawson accepted and brought a colleague—Bailey Willis.

  Little is known about their visit except that, one evening after a day of fieldwork and before dinner, Noble asked his guests if they might like a drink and what they would have. As Noble later told the story, Willis replied with a cool detachment. “Nothing at all,” the Stanford professor said. “Scotch and soda,” was the response from Lawson, maintaining his well-known privilege of always differing with Willis.

  But as to the San Andreas Fault and whether it could have accumulated miles of horizontal offset, the professors were in complete agreement: Over the long term, the Earth’s crust shifted vertically, not horizontally, raising mountains and lowering basins. The 20 feet or more of horizontal movement during the 1906 earthquake had been an aberration. Future earthquakes along the San Andreas would counter that movement.

  As if to reinforce their rare agreement, many years later at a scientific meeting that both attended, the speaker had given what he thought was compelling evidence that there was at least the possibility of the Earth’s crust sliding horizontally after repeated earthquakes. As one person who attended the meeting recalle
d, Lawson, who was sitting in the front row, rose to his feet and announced, “I may be gullible! But I am not gullible enough to swallow this poppycock!” Then Willis, who was sitting in the second row, got up and turned to the audience and said, “All you here today bear witness—for this is the first time in 20 years I find myself in complete agreement with Andy Lawson.”

  And so it went. Noble’s evidence was questionable and was dismissed, unsupported by any other observations. Besides, no one had another mechanism in mind to explain how the Earth’s crust might slide horizontally for many miles. It had to be the result of earthquakes along the fault.

  In 1926 Noble gave a presentation of his work along the San Andreas Fault at a scientific meeting in Japan. It did not go well. By his own admission, it was “a traumatic experience.” This fretfully shy man had to stand in front of an audience—this is the only time on record that he ever did so—and describe his work. He had taught himself a few words of Japanese and tried to incorporate them into his presentation with dismal results. There is no evidence that anyone was swayed by his work. And that was just as well, because Noble’s primary goal of going to Japan was not to convince others of his conclusion but to feel an earthquake.

  Japan is a country of frequent earthquakes. One is felt almost every day somewhere in the island nation. But during the four weeks Noble was in Japan, no earthquakes were felt at the places he visited.

  The only seismic shaking of note he did feel during his whole life was in 1933. The event was centered near Long Beach south of Los Angeles, doing a considerable amount of damage and causing more than 100 fatalities.

  At Long Beach, the walls of many buildings collapsed, houses were displaced from their foundations, and oil derricks caught on fire. In Pasadena, 30 miles north, people reported a moderate amount of shaking that caused some articles to fall from shelves and cracked the walls of some buildings. At Valyermo, 80 miles north of Long Beach, the shaking was perceptible, though slight.

  The shaking occurred during the early evening. Dorothy and Levi were in the kitchen. They quickly turned off the burners and went outside. Dorothy wondered whether this might be the big earthquake that Levi was waiting for, but he said it was not. They would have to wait longer.

  Years later, near the end of his life, Levi Noble would tell people that for some reason God had decided to deny him the experience of truly strong seismic shaking. Even the San Andreas Fault, where he had made his home and lived for 55 years, did not produce a significant event.

  After Japan, his interest shifted and he spent most of his professional time working along the northern extreme of the Mojave Desert along the Tehachapi Mountains and at Death Valley. He and Dorothy officially made their cabin built of railroad ties at Shoshone their official voting residence, being dedicated Republicans, so that they would offset the strong Democratic majority of the other residents.

  In 1965, at age 83, after two years of illness, Levi left California for the last time. He and Dorothy moved into the four-storied mansion in Auburn that had been his childhood home. He gave strict instructions to his staff of servants that he wanted the mansion maintained exactly as it had been when he was a boy, including the placement of his small childhood gloves on a stand next to his bed.

  Two months after moving into the mansion, Levi fell and broke his ankle. He was now confined to a wheelchair. One night, Dorothy thought she heard him stirring. She asked if everything was all right. There was no answer. She found him lying lifeless. He had died during the night.

  Levi Noble was buried on a hillside that looked over the Auburn mansion. His death on August 4, 1965, came 11 days after the publication of the first scientific paper that proposed the Earth’s surface consisted of several large mobile plates. In that paper, authored by Canadian geophysicist J. Tuzo Wilson and published in the British journal Nature, Wilson specifically identifies the San Andreas Fault as a plate boundary where there are “large horizontal movements,” seemingly supporting Noble’s previously mocked claim of 25 miles of horizontal displacement along the fault.

  But here is the irony. Noble’s conclusion about the San Andreas Fault was right, but for the wrong reason. The tightly cemented, deeply pockmarked sandstones that stand high as steep ridges—known in geology by the picturesque term “hogback”—as the Mormon Rocks and the Devil’s Punchbowl are not the same geologic unit and so could not have been split and slid apart by the San Andreas Fault. The two sandstones did form in similar environments—deposited by streams that flowed westward from the Mojave Desert—but they did not form at the same time. This came to light in 1972, seven years after Noble’s death, when vertebrate bones of the mid-Miocene horse Merychippus tehachapiensis were found in the Mormon Rocks, indicating those sandstone beds were at least 5,000,000 years older than those exposed at the Devil’s Punchbowl, where recovered fossils indicate those rocks were deposited during the late-Miocene about 12 million years ago.

  Though Noble was wrong, he did have an influence on the next generation of geologists who would examine the San Andreas Fault in greater detail. They would uncover many geologic units that have been split and slid apart by the fault, determining that the maximum amount of horizontal movement has been hundreds of miles, far greater than the 25 miles Noble had originally hypothesized.

  But before this next generation of geologists began their work, Levi Noble had a contemporary who was also deeply interested in the San Andreas Fault and in California earthquakes, though in a decidedly different way. His name was Charles Richter.

  Chapter 6

  The Troubled World of Charles Richter

  I am a dubious work of art.

  —Charles Richter, 1976

  He was born Charles Kinsinger and did not claim the name Richter—his mother’s maiden name—until he was 26 years old, a few years after fate took him into seismology. According to his mother, she and his father married each other twice, each marriage lasting long enough to produce one child and both marriages ending in divorce.

  The first one produced a daughter, Margaret Rose, in 1892. The second resulted in Charles Francis, born in 1900. Both brother and sister were beset with mental and emotional problems throughout their lives that eventually led Margaret to live much of her life inside a sanatorium. Her brother seemingly compensated for his own issues by maintaining a lifelong fascination with numbers and calculations and by engrossing himself in the fantastic worlds described in science fiction magazines such as Other Worlds, Thrilling Wonder Stories, and the ever-popular Amazing Stories. Both Margaret and Charles wrote poetry. He became a nudist. And in the public’s mind, he is the world’s most famous seismologist.

  Other researchers contributed more to a fundamental understanding of earthquakes than he did, but it was Richter’s accomplishment that has captured the public’s imagination. Given the chaos that earthquakes cause and the lingering and unsettled feelings that follow such events, he found a way to quantify and compare—that is, to assign single numbers—to what seems to be a hopelessly complicated yet primordially frightening events. “What was the magnitude?” is the first question invariably asked today after one has heard that an earthquake has struck distant Sumatra or nearby San Francisco or anywhere else. And he developed his magnitude scale, initially, for southern California—for earthquakes along and near the San Andreas Fault.

  Born on a farm in Ohio, Richter moved with his mother and sister to southern California in 1909, the family settling in the Wilshire area of Los Angeles. Introverted, as well as shocked by the fast pace of city life and by the combativeness of some children, he found refuge, as many children do who feel lonely and out of place, by going to libraries and reading books. His inclination to mathematics caused him to gravitate toward books about science, an interest that led him to enroll in Stanford University, where he received a degree in physics in 1920. The next year he began graduate studies at Stanford, but left suddenly and returned to Los Angeles, where soon
after he had his first major emotional breakdown.

  Exactly what the affliction was is not known, but in an engaging biography, Richter’s Scale, the author Susan Elizabeth Hough, an accomplished seismologist in her own right, explored the possibility that Richter suffered from Asperger’s syndrome, an illness that was not recognized and described until 1944, when Richter was well into middle age. Symptoms include discomfort in social situations, physical clumsiness, and an obsession with a narrow subject. Such characteristics are not uncommon among those who excel in scientific research, but for those who have Asperger’s syndrome, the behavior is extreme, considered by some to be a mild form of autism. Richter suffered the additional symptom of episodes of uncontrolled and unexplained weeping.

  Back in Los Angeles, Richter put himself under the care of the same psychiatrist who had treated his sister and he voluntarily lived for a time at a sanitarium. After a year, he left and found a job as a messenger for a museum in Los Angeles. Later, he went to work as a clerk in a hardware warehouse. It was during that time, in 1923, that he heard that Robert Millikan, the new president of the California Institute of Technology in Pasadena and a recent recipient of a Nobel Prize in physics, was giving a series of public lectures in which he would describe the experiments that had led to the award. Richter decided to attend those lectures.

  The lectures reenergized Richter’s interest in physics and mathematics, and he soon submitted an application to the institute and was admitted to the graduate program. In fact, it was Millikan who suggested a subject for him to study—to use the new ideas of quantum mechanics, which had its roots in a scientific paper contributed by Albert Einstein in 1905, to calculate the behavior of a hydrogen atom with a single spinning electron. As Richter was nearing the end of his work, for which he would receive a doctorate degree, Millikan called him into his office.