1906 Earthquake and the Great Silence
The question is raised: When did people in 1906 realize how widespread and severe the damage was after the earthquake on April 18? Those who were in Berkeley—Berkeley was then the fourth largest city in California, after San Francisco, Los Angeles and Oakland—felt strong shaking, but saw little evidence of damage. Andrew Lawson, who had discovered the San Andreas fault in 1896 and who was a professor of geology at the University of California, had gone on foot and done a quick assessment of the damage. He recorded that some brick chimneys on houses had collapsed, including on his own house. Many book shelves at the university library had tumbled. And there was broken glass scattered across the floor of the chemistry laboratory. But, other than that, there was little damage. And Lawson doubted whether there had been a significant earthquake. But evidence eventually came to light that led him to a different conclusion.
First, by midmorning, columns of smoke could be seen rising across the bay from parts of San Francisco. By mid afternoon, these half-dozen or so columns had coalesced into a huge single billowing black cloud that towered over the city, the top of which was drifting eastward toward Berkeley. He could also hear detonations from explosions coming from San Francisco. But exactly what had happened was still a mystery.
There were, of course, rumors coming from people crossing the ferries and landing in Oakland, but the stories they told did not have credibility and at this point were regarded as rumors. Obviously, the shaking had affected San Francisco. But how extensive was damage? What other regions were effected.
And then there was the great silence. All telephone lines and all but one telegraph wire out of San Francisco had been cut off at the moment of the earthquake. And there was no communication coming from either south of the city from Stanford or San Jose or from the north from Santa Rosa or Petaluma.
So when did Lawson and other scientists first realize the enormity of the event? The news came by a bicyclist from Lick Observatory on Mount Hamilton.
The name of the person who brought the news is now lost to history. But it is known that after the earthquake hit, the astronomers at Lick Observatory wanted to send a message to their colleagues at the university in Berkeley that the telescopes and themselves were unharmed. They tried to use a telephone, but the connection was down. And so someone was sent by bicycle.
It is twenty-six miles from Lick Observatory to San Jose, all downhill. Upon reaching that community, the rider saw that all was confusion. Gas lines were broken and all but a few buildings had collapsed. And there were no telephone or telegraph links to the outside. And so the rider continued on his way.
It is another fifty miles to Berkeley. He passed through a string of small communities—Milpitas to Fremont, Hayward to San Leandro. In places, he had to walk his bicycle around gaping cracks or debris scattered in the road. He reached Berkeley in the late afternoon and reported directly to Lawson what he had seen. That was the first indication of how extensive the strong ground shaking was and how wide-spread the damage.
It also prompted Lawson to send a recommendation to the governor of California, who was in Sacramento, to establish immediately a scientific commission to study what had just happened. The governor appointed Lawson to lead the commission. It was the work of that commission that showed the shaking of the 1906 earthquake had been caused by a 250-mile, continuous rupture of the San Andreas fault, from Shelter Cove near Cape Mendocino to the old Spanish mission at San Juan Bautista.