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Roger Weller, geology instructor

by Darion Jones
Physical Geology
Spring 2013


The Great San Francisco Earthquake

          It all started at 5:12 in the morning on April 18, 1906, the great earth quake struck San Francisco. In a matter of seconds approximately 700-3000 people were killed. This earthquake ruptured the San Andres fault, and devastated Northern California areas like San Jose, Santa Rosa, and Santa Cruz. One this quake hit, fires almost immediately erupted across the area as well as buildings collapsing, and gas lines breaking.


          Scientists still havenít been able to figure out the exact magnitude of this earthquake due to the lack of scientific instruments in those early times. But some have guessed that the earthquake was about a 7.7-7.9 magnitude on the Richter scale. As a result to this earthquake many were left homeless, and the relief effort quickly came in from all around the world. Fires destroyed about 28,000 buildings, 225,000 were left homeless.

          The relief effort to help this city came from all over with countries like China, and Japan. Due to racial prejudices, funds were kept away from the Asian-Americans at that time. The U.S. Military played a significant role in the relief effort as the Navy ran water lines throughout the city to help put out fires, and provide water to the fire department for their steam engines. The army on the other hand ran 21 refugee camps providing food, water, clothes, and other important necessities that the people needed.

                   Discrimination once again left out the Asian-Americans as they were forced to move from refugee camp to refugee camp. Relief cottages were only permitted to earthquake refugees who were:

1.        You must be a permanent camp resident

2.        If you were in a tent or makeshift building

3.        If you were staying in cellars or with friends

4.        Lastly, if you were a San Franciscan forced to live outside the city

At that time for fifty dollars a refugee could buy a cottage that would then be moved to a rental lot in which they would have to pay $3 to $15 dollars per month.

          This earthquake was so powerful it was felt all the way to Los Angeles and Oregon. This also was the first large natural disaster that was recorded by photography.  So what is an earthquake? An earthquake is when the ground moves caused by when two blocks of the earth slips past one another. Earthquakes are caused by when the tectonic plates have moved far enough off of the plate boundaries. The plate boundaries are the faults, and the faults are where earthquakes are more likely to happen.

          Why does the earth shake? It shakes because of the energy the earthquake radiates towards the fault forms seismic shockwaves like ripples in a pond. Earthquakes are very common in San Francisco because of the San Andres fault. The best thing to do during an earthquake is to cover your head, get under a desk, in between doorways, or go outside where nothing will be able to fall on you.