The 1906 San Francisco earthquake offered Reid the chance to take his interest in seismology to a new level . Andrew Lawson was then chair of the geology department at the University of California at Berkeley , and Lawson had been one of the first ( 1888 ) Hopkins Ph.D. s in geology . Perhaps through his influence Reid was chosen the only non-Californian to study the great earthquake as part of a state-funded commission . Through a close examination of how different points of land along the California coast and nearby inland had moved over the course of the previous half century - here his access to USGS data was crucial - Reid was able to determine that the earthquake was a result of forces he identified as “ elastic strain . ” This strain had built up slowly but unequally at points along the San Andreas Fault , and it took a massive temblor to release the strain at that point along the fault where the greatest energy had accumulated
1906 San Francisco earthquake
1906 San Francisco earthquake
Harry Fielding Reid