100 years after San Francisco quake
Read more about the 1906 Great San Francisco Earthquake in the April 2006 Geotimes Benchmarks, now available online.
Early morning, April 18, 1906: A massive 7.8-magnitude earthquake strikes just 3 kilometers off the coast of San Francisco in the Pacific. The San Andreas Fault, not yet named or understood, slipped 430 kilometers in a minute. Houses built on soft "fill" sediments collapsed, and water mains and gas lines broke. Although the earthquake caused extensive damages, it was the breaking gas lines that actually brought down the city, in a series of devastating fires.
On April 18, 1906, a massive earthquake struck San Francisco, Calif., and set off a series of some 50 fires raging across the city. This photograph shows the wreckage of the Emporium Building on Market Street in the wake of the quake and fires. Photo is courtesy of the U.S. Geological Survey.
One hundred years later, the "City by the Bay" is alive and well. To mark the anniversary of the Great San Francisco Earthquake, thousands of geologists, engineers, politicians, emergency responders and interested members of the public are descending on downtown San Francisco for a three-day conference this week on earthquakes and related events commemorating the 1906 event. If you're in San Francisco this month, be sure to check out some of the special earthquake events and exhibits.
But no matter when you head to the Bay Area, the list of geologically interesting locations to visit is long and varied, from Point Reyes National Seashore just north of the city, where you can actually see the San Andreas Fault and the 6 meters of displacement caused by the 1906 quake, to the serpentinite hills of Marin County and Mount Tamalpais State Park. A stroll through the city, however, will give you a unique perspective on the 1906 quake and the ensuing fire that consumed the city.
One of the most famous buildings still standing in the wake of the quake and fire would be a good place to begin an earthquake-inspired tour of the city: the U.S. Court of Appeals building.
If you're visiting San Francisco, consider following the trail of the 1906 earthquake, and starting with the old post office building, now housing a U.S. Court of Appeals, at Seventh & Mission streets in downtown San Francisco, as pictured here in a 1905 postcard. Photo is courtesy of the National Park Service.
In the heart of downtown San Francisco, at Seventh and Mission streets, the Court of Appeals building was completed in 1905 as a federal courthouse and post office and is on the National Register of Historic Places. A quick tour inside reveals walls and columns of marble from Vermont and Maryland, as well as Italy and North Africa; rich mahogany from Mexico and East India; and local California redwood.
The courthouse was spared extensive damage in the 1906 quake and fire, so it was restored pretty quickly. The 1989 Loma Prieta temblor did, however, badly damage the building. Luckily for visitors today, the U.S. General Services Administration chose to restore it to its former glory, and actually retrofitted it to withstand future temblors, by putting an innovative base-isolation system beneath it.
After your quick tour, step back outside and walk a few blocks up Market Street toward Union Square, which was leveled in the 1906 quake, but was quickly rebuilt and became the city's premier shopping district. Today, Union Square hosts a multitude of hotels and restaurants at varying price levels (though none are very cheap), and boutique and department stores galore. If you can afford it, it's a good place to stay, as it is close to everything.
On the way, though, grab a map of the city at the San Francisco Visitors Center near the Powell Street BART (Bay Area Rapid Transit) station (a couple blocks shy of the square) the start of the Powell/Hyde and Powell/Mason cable car lines. Hop aboard one of San Francisco's famed cable cars, which will take you to Fisherman's Wharf, via Union Square.
The cable cars nearly lost out to streetcars following the earthquake, as you learn 