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SSA Turns 100

July/August 2004

The 1906 San Francisco Earthquake and Its Significance to the Scientific Community

The 18 April 1906 San Francisco earthquake is the first seismic event in the nation's history to truly capture the attention and imagination of the broad citizenry of the United States. From "The Complete Story of San Francisco's Terrible Calamity of Earthquake and Fire" (Livingstone, 1906) to "San Francisco's Horror of Earthquake and Fire" (Wilson, 1906), numerous and varied popular works depicted the event through prose, photographs, verse, and even song. Several books took the opportunity to place the 1906 earthquake in the context of other world disasters, such as the eruption of Mount Vesuvius.

The earthquake also marked the formal introduction of the San Andreas Fault to the international scientific community--and California's citizenry. Although a section of the fault along the San Francisco peninsula had been mapped by Andrew Lawson and is shown in his 1893 publication, and named in his 1895 publication, no special importance had been placed on this fault. However, the 435-km-long fault surface rupture from San Juan Bautista in the south to north of Shelter Cove that accompanied the 1906 earthquake focused the attention of scientists around the world on the San Andreas Fault. After the earthquake, the fault was followed and mapped south of the surface rupture as far as San Bernardino in Southern California, and its association with earthquakes became well known. Today, the San Andreas is by far the most famous fault in North America, and perhaps the world, and has become a cultural icon associated with California as much as the Hollywood sign, the Golden Gate Bridge, or surfers riding Pacific waves. It is also one of the most thoroughly studied faults on Earth.

The scientific inquiry conducted in the aftermath of the earthquake was among the world's earliest comprehensive postearthquake investigations, and was the first conducted in the western U.S. The State Earthquake Investigation Commission convened by Governor Pardee was chaired by Andrew Lawson of the University of California and included four geologists (A. C. Lawson, J. C. Branner, G. K. Gilbert, and H. F. Reid) and four astronomers (C. Burckhalter, W. W. Campbell, G. Davidson, and A. O. Leuschner). The Commission filed a preliminary report of 20 pages on 31 May 1906, with the final report published in two volumes: the first edited by Lawson (1908), the second by Reid (1910). After nearly a century, the Report of the State Earthquake Investigation Commission (referred to commonly as "The 1906 Report") still provides valuable data and insights for modern research on earthquakes and faults (c.f. Prentice and Schwartz, 1991; Wald et al., 1993; Brown, 1995; Prentice and Ponti, 1997; Thatcher et al., 1997; Prentice et al., 1999) and remains a model for postearthquake investigations today.

Many of the important ideas that underpin the fields of geology, geodesy, and seismology can be found in the 1906 Report. Wood (in Lawson, 1908, pp. 220-245) observed that the amount of damage in different districts within San Francisco was distinctly related to the nature of the surficial materials, and other workers made similar observations in other regions along the rupture. Gilbert pointed out that the geomorphic features he observed along the San Andreas Fault provided clear evidence of repeated earthquakes, expanding on his previous observations of evidence for recurrent earthquakes along the Wasatch Fault in Utah (Gilbert, 1883). Reid (1910) explained the relevance of geodetic measurements and, with his description of elastic rebound theory, provided a conceptual model for understanding earthquake recurrence. These represent only a few examples of concepts that have roots in The 1906 Report.

The centennial of this watershed event will be marked by a joint conference including the annual meeting of the Seismological Society of America (SSA), the 8th National Conference of the Earthquake Engineering Research Institute (EERI), and the Disaster Resistant California (DRC) meeting of the California Governor's Office of Emergency Services. The meeting will be held in San Francisco 18-24 April 2006. Without question, this is going to be THE place for scientists, engineers, planners, policy makers, and responders to come together and commemorate the San Francisco earthquake and celebrate 100 years of progress in understanding and mitigating earthquakes throughout the world. Mark your calendars now, and don't forget to check the Web site (http://www.1906eqconf.org/) for more information as the time draws near.


Brown, R. D. (1995). 1906 surface faulting on the San Andreas Fault near Point Delgada, California, Bulletin of the Seismological Society of America 85, 100-110.

Gilbert, G. K. (1883). A theory of the earthquakes of the Great Basin, with a practical application, Salt Lake City Tribune, 30 September 1883; reprinted in 1884 as American Journal of Science, 3rd ser., 27, 49-53.

Lawson, A. C. (1893). Post-Pliocene diastrophism of southern California, Geological Sciences 1, 115-160, California University Publications.

Lawson, A. C. (1895). Sketch of the geology of the San Francisco Peninsula, California, U.S. Geological Survey, 15th Annual Report, 399-476.

Lawson, A. C. (1908). The California earthquake of April 18, 1906, Report of the State Earthquake Investigation Commission, Carnegie Institute of Washington, Publication 87, 451 pp.

Livingstone, A. P. (1906). Complete Story of San Francisco's Terrible Calamity of Earthquake and Fire, Continental Pub. House.

Prentice, C. S., D. J. Merritts, E. Beutner, P. Bodin, A. Schill, and J. Muller (1999). The northern San Andreas Fault near Shelter Cove, California, Geological Society of America Bulletin 111, 512-523.

Prentice, C. S. and D. J. Ponti (1997). Coseismic deformation of the Wrights tunnel during the 1906 San Francisco earthquake: A key to understanding 1906 fault slip and 1989 surface ruptures in the southern Santa Cruz Mountains, California, Journal of Geophysical Research 102, 635-648.

Prentice, C. S. and D. P. Schwartz (1991). Re-evaluation of 1906 surface faulting, geomorphic expression, and seismic hazard along the San Andreas Fault in the southern Santa Cruz Mountains, Bulletin of the Seismological Society of America 81, 1,424-1,479.

Reid, H. F. (editor) (1910). The California earthquake of April 18, 1906, Report of the State Earthquake Investigation Commission, Volume II, The Mechanics of the Earthquake, Carnegie Institute of Washington, Publication 87, 192 pp.

Thatcher, W., G. Marshall, and M. Lisowski (1997). Resolution of fault slip along the 470-km-long rupture of the great 1906 San Francisco earthquake, Journal of Geophysical Research 102, 5,353-5,367.

Wald, D. J., H. Kanamori, D. V. Helmberger, and T. H. Heaton (1993). Source study of the 1906 San Francisco earthquake, Bulletin of the Seismological Society of America 83, 981-1,019.

Wilson, J. R. (1906). San Francisco's Horror of Earthquake and Fire, National Publishing Company.

Carol S. Prentice and Lind Gee



Posted: 23 July 2005