September 5, 2006 > The Great Shake of '68 exhibit opens at Historical Society museum
The Great Shake of '68 exhibit opens at Historical Society museum
by Jim DeMersman
Unless you have been living under a rock the last few months, you have heard a lot of talk about the 100th anniversary of the 1906 earthquake-the largest quake to hit a major metropolitan area in California to date. That event caused so much devastation throughout the Bay Area and especially in San Francisco that it has sometimes been referred to as "The Great Quake" or "The Great San Francisco Earthquake." But did you know that the first "Great Quake" actually occurred in 1868 on the Hayward fault?
On the morning of Oct. 21, 1868, a rumbling noise startled residents. The ground began shaking. Some witnesses reported seeing the ground roll, knocking them from their feet, and the mountains sort of "skipping." Buildings cracked and groaned, some portions collapsing. The estimated 7.0 magnitude earthquake shuddered along the Hayward fault leaving destruction in its wake. When the trembling finally stopped after what seemed an eternity, but was probably no more than 40 seconds, Hayward lay in ruins. Almost every home and business in the small community was damaged. Chimneys fell. Outside stairways peeled away from their moorings. Ceilings and walls gave way. Houses slid from their foundations. Several warehouses in the business district, around D Street and Watkins, collapsed. Falling debris injured several people and nerves were rattled but, remarkably, no one was killed.
Cracked or collapsed buildings were reported in San Lorenzo, Castro Valley, Mt. Eden, Niles, Centerville, Mission San Jose, Oakland, Berkeley, Santa Rosa, and other surrounding towns. In San Leandro, at that time the county seat, the Alameda County courthouse fell. A falling column, which decorated the building faŤade, killed deputy county clerk, J.W. Josselyn, as he ran in panic from the building. His death was the only reported fatality in the east bay. Buildings in San Francisco also suffered severe structural damage. The majority of the devastation occurred in neighborhoods closest to the bay, primarily in the business district. There were four documented deaths and numerous injuries.
In newspaper articles in the following days, extensive reports of damage appeared. Many of these reports also stated that the damaged buildings were those built poorly using cheap materials, not secured to their foundations or built on stilts, like some in Hayward. Editorials stated that buildings built on made-ground, or landfill, seemed to suffer greater damage. In fact, with these comments in mind, the San Francisco Chamber of Commerce commissioned a study on the effect of the earthquakes on structures. Had the report been completed and published, these findings might have been taken into account as the rebuilding began. In the long run, the report never appeared and the effects of the quake were actually downplayed in the media in ensuing months and years.
As with all natural disasters, buildings were rebuilt and life went on only to be rattled again by the even larger earthquake of 1906. What was the difference between these two events? They happened on different faults. The 1906 event occurred on the San Andreas Fault, which runs almost the entire length of California, while the 1868 event occurred on the Hayward fault, which extends roughly from the Santa Clara county line in the south to San Pablo Bay in the north. Much to the dismay of scientists, this was the last time the Hayward fault had an eruption of any significance. That's not good for those of us living and working along the fault today. The Hayward fault creeps by millimeters every year; evidenced by warped buildings and sidewalks, relieving some of the stress on the fault deep within the earth. However, the general belief is that the creeping does not do enough. Scientists predict that the Hayward fault has a 27 percent chance of producing a 6.7 or greater magnitude earthquake within the next 30 years. It is potentially the most dangero