REID, HARRY FIELDING

(b. Baltimore, Maryland, 18 May 1859; d. Baltimore, 18 June 1944)

geophysics.

Reid, who may well be said to have been the first geophysicist in the United States, was the son of Andrew Reid and of Fanny Brooks, a grandniece of George Washington. His family spent some time in Switzerland when he was a child, and this led to a lifelong love of mountains and to his great interest in the mechanics of glaciers. In his early manhood glaciology was his principal interest.

Reid entered johns Hopkins in 1876 and received his Ph. D. there in 1885. He proceeded to Case School of applied Science as professor of mathematics and later was professor of physics. In 1894, after a year of teaching at the University of Chicago, he returned to his alma mater, where he taught until his retirement in 1930.

Reid’s greatest contribution to geophysics was undoubtedly his masterful exposition of the “elastic rebound theory’, of the immediate source of earth quake waves—the cause of earthquakes. The theory states that elastic strain accumulates slowly in the earth’s rocky crust as a result of forces, presumably acting from below the crust, of uncertain origin. When this strain becomes too great for the crustal rocks to bear, they break along faults. The frictional grinding of the two sides of the fault against each other produces the elastic wave motion which we call an earthquake. The association of some earthquakes with surface fault breaks was recognized early, but many felt that fault breaks were the result of an unspecified sudden catastrophe at depth.

The theory was generally adopted in the United States, but it took sixty years for it to be widely accepted in Japan and in Europe. Reid was on the committee appointed by the governor of California to report on the earthquake of 1906. He recognized the significance of the changes in position of various bench marks of the U.S Coast and Geodetic Survey both before and during the earthquake. His careful analysis of this somewhat sparse data, plus his knowledge of mechanics and perhaps intuition, led him to the statement of the “elastic rebound” theory.

BIBLIOGRAPHY

A complete bibliography of Reid’s writings, prepared by M. F. Alvey, is part of Edward W. Berry, “Memorial to Harry Fielding Reid,” in Proceedings of the Geological Society of America (1944), 295–298. Among his works are “Mechanics of Glaciers,” in Journal of Geology, 4 (1896), 912–918; “Geometry of Faults,” in Bulletin of the Geological Society of America, 20 (1909), 171–196; The California Earthquake of April 18, 1906. The Mechanics of the Earthquake, vol. II of Report of the State [California] Earthquake Investigation Commission, which is Carnegie Institution of Washington, publication no. 87, vol II (Washington, 1910); “The Elastic-Rebound Theory of Earthquakes,” in Publication of the University of California, Bulletin of the Department of Geology, 6 (1911), 413–444; “Isostasy and Mountain Ranges,” in Proceddings of the American Philosophical Society, 50 (1911), 444–451, also in Bulletin of the American Geographical Society of New York, 44 (1912), 354–360; and “The Mechanics of Earthquakes; the Elastic Rebound Theory; Regional Strain,” in Bulletin of the National Research Council Washington, 90 (1933), 87–103.

For information on Reid see the Berry article mentioned above.

Perry Byerly

Reid, Harry Fielding (1849–1944) An American geophysicist, Reid proposed the ‘elastic rebound’ theory of earthquake motion after studying the 1906 San Francisco earthquake. He was a vigorous opponent of continental drift theory, describing Wegener's work as ‘pseudo-scientific’.