Summary
Though among the most famous earthquakes in modern times, San Francisco (18 April 1906) has almost always been presented as nothing more than a great human disaster. While certainly that, we should regard it also as having had unusual significance in the development of seismology. Because the full extent of the San Andreas fault was thereafter recognized, and the association between faulting and earthquakes confirmed, we may consider the San Francisco earthquake of 1906 to be the first in which modern understanding of seismic causality prevailed.