(b. Darmstadt, Germany, 4 June 1889; d. Pasadena, California, 25 January 1960)
Gutenberg was the son of Hermann Gutenberg, a soap manufacturer, and Pauline Hachenburger Gutenberg. He attended the Realgymnasium and Technische Hochschule in Darmstadt, taking intensive courses in mathematics, physics, and chemistry. He intended to specialize in mathematics and physics at the University of Göttingen, but an interest in weather forecasting and climatology led him to Emil Wiechert’s course on instrumental observation of geophysical phenomena at the new geophysical institute there. He took all of Wiechert’s courses until he was told that he had learned practically all that was known in seismology. For his Ph.D. (1911) he elected to study microseisms.
From 1911 until 1918 (with an interruption for army service) Gutenberg was assistant at the International Seismological Association in Strasbourg; in 1918 he became Privatdozent at the University of Frankfurt-am-Main, where he was appointed professor of geophysics in 1926. His father died that year, and Gutenberg also undertook the management of the family business.
In 1930 Gutenberg accepted a professorship at the California Institute of Technology. This post also provided him with research facilities at the Seismological Laboratory of the Carnegie Institution there, which had an extensive network of seismograph stations, together with good recording instruments; it became part of the California Institute of Technology in 1936 and Gutenberg was its director from 1947 to 1958.
Gutenberg began in seismology with the most complex and frustrating topic in the field: the origin of microseisms. In his thesis and a number of later papers he considered most of the presently known sources for microseismic disturbances. Soon thereafter he produced his most elegant piece of research: following earlier suggestions by Wiechert and by R. D. Oldham, he computed the travel times of waves that would be affected by a low-velocity core of the earth, searched seismograms for them, demonstrated the existence of the core and measured its depth (2,900 kilometers) to an accuracy that still stands.
Gutenberg’s early interest in meteorology led him to studies of the structure of the upper atmosphere. Noting the curious ring zones of silence and signal around strong air blasts, he derived the general curves for temperature in the ionosphere.
With Charles F. Richter, he derived improved travel-time curves for earthquakes (and determinations of velocity within the earth) while similar work was being done by Harold Jeffreys and Keith Bullen. The difference in approach is well exemplified by the derivation of these curves. The Jeffreys-Bullen curves were derived by statistical methods from a large volume of data from many sources; those by Gutenberg and Richter were from fewer data, from seismograms individually examined. Gutenberg derived improved methods of epicenter and depth determinations (using advanced instruments developed by Hugo Benioff), extended Richter’s magnitude scale to deep-focus shocks, and, with Richter, determined the quantitative relations between magnitude, energy, intensity, and acceleration.
Studies of amplitude variations of compressional waves gave Gutenberg initial evidence that low-velocity layers existed within the earth. Using precise determinations of focal depth, he determined the variation of travel times as a function of source depth and thus the fine-scale variations of velocity in the upper mantle, demonstrating the existence of a low-velocity channel at a depth of between 100 and 200 kilometers. This channel is essential to theories of crustal movements.
One widely quoted hypothesis of Gutenberg’s has proved invalid. From studies of surface wave velocities, and of reflection of compressional waves beneath the oceans, he concluded that the Atlantic basin was nearly continental in average structure as contrasted with the “truly oceanic” structure of the Pacific. Later work at sea has shown that the anomaly he found was due primarily to the much larger proportion of the Atlantic occupied by the mid-ocean ridge.
With Richter, Gutenberg redetermined the locations of all major earthquakes, showing both the patterns of seismicity and the geometry of the deep-focus earthquakes. Both seismologists and geologists are indebted to Gutenberg. Among the former he will be remembered best for his studies of the core and for his travel times all thorough studies of the phases of earthquake arrivals in “On Seismic Waves”; the latter use Internal Constitution of the Earth (which he edited, and wrote large portions of) and Seismicity of the Earth as standard sources.
I. Original Works. Among Gutenberg’s more outstanding works are “On Seismic Waves,” in four pts., in Beiträge zur Geophysik, 43 (1934); 45 (1935); 47 (1936); and 54 (1939), written with C. F. Richter, which contains much of his work on earthquake travel times and studies in teleseisms; Internal Constitution of the Earth (New York, 1939; 2nd ed., 1951); and Seismicity of the Earth (New York, 1941), written with Richter, which gives the world-wide geography of earthquakes in a useful format.
A revision of the travel times is “Epicenter and Origin Time of the Main Shock on July 21 and Travel Time of Major Phases.” in G. B. Oakeshott, ed., Earthquakes in Kern County, California During 1952, California Division of Mines Bulletin 171 (San Francisco, 1955), pp. 157–163. For Gutenberg’s summary of seismologic research at three stages over a span of two decades, see The Physics of the Earth’s Interior, International Geophysics Series, vol. I (New York, 1959). Richter’s memorial, cited below, includes a bibliography.
II. Secondary Literature. Gutenberg’s life and contributions to seismology are summarized in H. Jeffreys, “Beno Gutenberg,” in Quarterly Journal of the Royal Astronomical Society, 1 (1960), 239–242; and C.F. Richter, “Memorial to Beno Gutenberg, 1889–1960,” in Proceedings of the Geological Society of America for 1960 (1962), pp. 93–104. Sidelights on Gutenberg’s early years appear in “Fifteenth Award of the William Bowie Medal,” in Transactions of the American Geophysical Union, 34 , no. 3 (1953), 353–355.
George G. Shor, Jr.
Elizabeth Noble Shor
GUTENBERG, BENO (1889–1960), geophysicist. Born in Darmstadt, from 1912 to 1923 Gutenberg was assistant at the International Seismological Bureau at Strasbourg. He was then appointed teacher at Frankfurt University, where he became professor in 1926. In 1930 he emigrated to the U.S. to take up the position of professor of geophysics and meteorology at the California Institute of Technology, Pasedena, where in 1946 he became director of the Seismological Laboratory. Gutenberg was the president of the International Association for Seismology (1951–54) and a member of the National Academy of Sciences in Washington. As one of the outstanding seismologists of the last decades, he confirmed the occurrence of earthquakes down to depths of 375 mi. (600 km.) and was the originator of the hypothesis of continental spreading (Fliess theory). He carefully analyzed the available information on the earth's interior and made the first exact determination of the earth's core at 1812 mi. (2,900 km.) below the surface and detected the "asthenosphere channel" at a depth of 62–124 mi. (100–200 km.). This discovery had a critical influence on identifying elastic waves produced by large artificial explosions. He also investigated the nature of the atmosphere. On the basis of the research of Lindemann and Dobson, Gutenberg revolutionized existing conceptions. He maintained that at the height of 31 mi. (50 km.) the temperature was probably as high as on the earth's surface, and that the composition of the atmosphere remained unchanged up to a height of 94 mi. (150 km.). He contributed a lot to modern geophysical ideas on the earth's crust and mantle. Among his works are Seismische Bodenunruhe (1924), Der Aufbau der Erde (1925), Grundlagen der Erdbebenkunde (1927), Lehrbuch der Geophysik (1929), the important Handbuch der Geophysik (1930), Seismicity of the Earth (with C.F. Richter, 1941), Internal Constitution of the Earth (1939), and Physics of the Earth's Interior (1959).
P. Byerly, in: Science, 131 (April 1960), 965–6; R. Stoneley, in: Nature, 186 (May 7, 1960), 433–4.