The 1906 earthquake preceded the development of the Richter magnitude scale by three decades. The most widely accepted estimate for the magnitude of the quake on the modern moment magnitude scale is 7.8; values from 7.7 to as high as 8.3 have been proposed. According to findings published in the Journal of Geophysical Research, severe deformations in the earth’s crust took place both before and after the earthquake’s impact. Accumulated strain on the faults in the system was relieved during the earthquake, which is the supposed cause of the damage along the 450-kilometer-long segment of the San Andreas plate boundary. Shaking was felt from Oregon to Los Angeles, and inland as far as central Nevada.
A strong foreshock preceded the main shock by about 20 to 25 seconds. The strong shaking of the main shock lasted about 42 seconds. There were decades of minor earthquakes – more than at any other time in the historical record for northern California – before the 1906 quake. Widely interpreted previously as precursory activity to the 1906 earthquake, they have been found to have a strong seasonal pattern and have been postulated to be due to large seasonal sediment loads in coastal bays that overlie faults as a result of the erosion caused by hydraulic mining in the later years of the California Gold Rush.
Dore Street. 1906 San Francisco earthquake
18th Street From Howard. 1906 San Francisco earthquake
Howard Street Between 17th and 18th. 1906 San Francisco earthquake
Howard Street Between 17th and 18th. 1906 San Francisco earthquake
Jones and Market. 1906 San Francisco earthquake
Youth’s Directory 19th Street. 1906 San Francisco earthquake
Boy’s Gymnasium, Stanford University, Palo Alto. 1906 San Francisco earthquake
”The Warren” Post and Jones. 1906 San Francisco earthquake
YMCA Building, Mason Street. 1906 San Francisco earthquake
Hall of Justice on Kearney Street. 1906 San Francisco earthquake
Dynamiting The Examiner Building. 1906 San Francisco earthquake
U.S. Mint, 5th and Mission Streets. 1906 San Francisco earthquake
Orpheum Theater. 1906 San Francisco earthquake
At Stanford University, Palo Alto. 1906 San Francisco earthquake
San Francisco Stock Exchange. 1906 San Francisco earthquake
Mason From Market Street. 1906 San Francisco earthquake
Market Street From Ferry. 1906 San Francisco earthquake
Mason South From Post. 1906 San Francisco earthquake
Observatory, Golden Gate Park, San Francisco. 1906 San Francisco earthquake
High School, Redwood City. 1906 San Francisco earthquake
Courthouse, Redwood City. 1906 San Francisco earthquake
House On Steiner Street. 1906 San Francisco earthquake
via SMU Central University Libraries
