Richter, Charles F. (1900-1985)

American seismologist

Charles F. Richter is remembered every time an earthquake happens. With German-born seismologist Beno Gutenberg, Richter developed the scale that bears his name and measures the magnitude of earthquakes. Richter was a pioneer in seismological research at a time when data on the size and location of earthquakes were scarce. He authored two textbooks that are still used as references in the field and are regarded by many scientists as his greatest contribution, exceeding the more popular Richter scale. Devoted to his work all his life, Richter at one time had a seismograph installed in his living room, and he welcomed queries about earthquakes at all hours.

Charles Francis Richter was born on a farm near Hamilton, Ohio, north of Cincinnati. His parents were divorced when he was very young. He grew up with his maternal grandfather, who moved the family to Los Angeles in 1909. Richter went to a preparatory school associated with the University of Southern California, where he spent his freshman year in college. He then transferred to Stanford University, where he earned an A.B. degree in physics in 1920.

Richter received his Ph.D. in theoretical physics from the California Institute of Technology (Cal Tech) in 1928. That same year he married Lillian Brand of Los Angeles, a creative writing teacher. Robert A. Millikan, a Nobel Prize-winning physicist and president of Cal Tech, had already offered Richter a job at the newly established Seismological Laboratory in Pasadena, then managed by the Carnegie Institution of Washington. Thus Richter started applying his physics background to the study of the earth.

As a young research assistant, Richter made his name early when he began a decades-long collaboration with Beno Gutenberg, who was then the director of the laboratory. In the early 1930s, the pair was one of several groups of scientists around the world who were trying to establish a standard way to measure and compare earthquakes. The seismological laboratory at Cal Tech was planning to issue regular reports on southern California earthquakes, so the Gutenberg-Richter study was especially important. They needed to be able to catalog several hundred quakes a year with an objective and reliable scale.

At the time, the only way to rate shocks was a scale developed in 1902 by the Italian priest and geologist Giuseppe Mercalli. The Mercalli scale classified earthquakes from 1 to 12, depending on how buildings and people responded to the tremor. A shock that set chandeliers swinging might rate as a 1 or 2 on this scale, while one that destroyed huge buildings and created panic in a crowded city might count as a 10. The obvious problem with the Mercalli scale was that it relied on subjective measures of how well a building had been constructed and how used to these sorts of crises the population was. The Mercalli scale also made it difficult to rate earthquakes that happened in remote, sparsely populated areas.

The scale developed by Richter and Gutenberg, which became known by Richter's name only, was instead an absolute measure of an earthquake's intensity. Richter used a seismograph—an instrument generally consisting of a constantly unwinding roll of paper, anchored to a fixed place, and a pendulum or magnet suspended with a marking device above the roll—to record actual earth motion during an earthquake. The scale takes into account the instrument's distance from the epicenter, or the point on the ground that is directly

above the earthquake's origin. Richter chose to use the term "magnitude" to describe an earthquake's strength because of his early interest in astronomy; stargazers use the word to describe the brightness of stars. Gutenberg suggested that the scale be logarithmic, so that a quake of magnitude 7 would be ten times stronger than a 6, a hundred times stronger than a 5, and a thousand times stronger than a 4. (The 1989 Loma Prieta earthquake that shook San Francisco was magnitude 7.1.)

The Richter scale was published in 1935, and immediately became the standard measure of earthquake intensity. Richter did not seem concerned that Gutenberg's name was not included at first; but in later years, after Gutenberg was already dead, Richter began to insist that his colleague be recognized for expanding the scale to apply to earthquakes all over the globe, not just in southern California. Since 1935, several other magnitude scales have been developed. Depending on what data is available, different ones are used, but all are popularly known by Richter's name.

For several decades, Richter and Gutenberg worked together to monitor seismic activity around the world. In the late 1930s they applied their scale to deep earthquakes, ones that originate more than 185 miles below the ground, which rank particularly high on the Richter scale—8 or greater. In 1941, they published a textbook, Seismicity of the Earth, which in its revised edition became a standard reference book in the field. They worked on locating the epicenters of all the major earthquakes and classifying them into geographical groups. All his life, however, Richter warned that seismological records only reflect what people have measured in populated areas and are not a true representative sample of what shocks have actually occurred. He long remained skeptical of some scientists' claims that they could predict earthquakes.

Richter remained at Cal Tech for his entire career, except for a visit to the University of Tokyo from 1959 to 1960 as a Fulbright scholar. He became involved in promoting good earthquake building codes, while at the same time discouraging the overestimation of the dangers of an earthquake in a populated area like Los Angeles. He pointed out that statistics reveal freeway driving to be much more dangerous than living in an earthquake zone. He often lectured on how loss of life and property damage were largely avoidable during an earthquake, with proper training and building codes—he opposed building anything higher than thirty stories, for example. In the early 1960s, the city of Los Angeles listened to Richter and began to remove extraneous, but potentially dangerous, ornaments and cornices from its buildings. Los Angeles suffered a major quake in February of 1971, and city officials credited Richter with saving many lives. Richter was also instrumental in establishing the Southern California Seismic Array, a network of instruments that has helped scientists track the origin and intensity of earthquakes, as well as map their frequency much more accurately. His diligent study resulted in what has been called one of the most accurate and complete catalogs of earthquake activity, the Cal Tech catalog of California earthquakes.

Later in his career, Richter would recall several major earthquakes. The 1933 Long Beach earthquake was one, which he felt while working late at Cal Tech one night. That quake caused the death of 120 people in the then sparsely populated southern California town; it cost the Depression-era equivalent of $150 million in damages. Nobel Prize-winning physicist Albert Einstein was in town for a seminar when the earthquake struck, according to a March 8, 1981 story in the San Francisco Chronicle. Einstein and a colleague of Richter's were crossing the campus at the time of the quake, so engrossed in discussion that they were oblivious to the swaying trees. Richter also remembered the three great quakes that struck in 1906, when he was a six-year-old on the Ohio farm. That year, San Francisco suffered an 8.3 quake, Colombia and Ecuador had an 8.9, and Chile had an 8.6.

In 1958, Richter published his text Elementary Seismology, which was derived from the lectures he faithfully taught to Cal Tech undergraduates as well as decades of earthquake study. Many scientists consider this textbook to be Richter's greatest contribution, since he never published many scientific papers in professional journals. Elementary Seismology contained descriptions of major historical earthquakes, tables and charts, and subjects ranging from the nature of earthquake motion to earthquake insurance and building construction. Richter's colleagues maintained that he put everything he knew into it. The book was used in many countries.

In the 1960s, Richter had a seismograph installed in his living room so that he could monitor quakes at any time. He draped the seismographic records—long rolls of paper covered with squiggly lines—over the backs of the living room chairs. (His wife, Richter maintained, considered the seismograph a conversation piece.) He would answer press queries at any hour of the night and never seemed tired of talking about his work. Sometimes he grew obsessive about speaking to the press; when a tremor happened during Cal Tech working hours, Richter made sure he would be the one answering calls—he put the lab's phone in his lap.

Richter devoted his entire life to seismology. He even learned Russian, Italian, French, Spanish, and German, as well as a little Japanese, in order to read scientific papers in their original languages. His dedication to his work was complete; in fact, he became enraged at any slight on it. For instance, at his retirement party from Cal Tech in 1970, some laboratory researchers sang a clever parody about the Richter scale. Richter was furious at the implication that his work could be considered a joke. During his lifetime he enjoyed a good deal of public and professional recognition, including membership in the American Academy of Arts and Sciences and a stint as president of the Seismological Society of America, but he was never elected to the National Academy of Sciences. After his retirement, Richter helped start a seismic consulting firm that evaluated buildings for the government, for public utilities such as the Los Angeles Department of Water and Power, and for private businesses.

Richter enjoyed listening to classical music, reading science fiction, and watching the television series Star Trek. One of his great pleasures, ever since he grew up walking in the southern California mountains, was taking long solitary hikes. Richter died in Pasadena at the age of 85.

See also Faults and fractures; Folds