Several months ago I was walking down the street in San Francisco when I noticed a large brass plaque embedded in the sidewalk. It said that the spot on which I was standing was once part of the shoreline of the San Francisco Bay. I turned and looked in the direction of the Bay, from which I was now separated by several blocks and quite a few very large buildings. Up until that time, it had never occurred to me to doubt Jefferson Starship’s claim, “We built this city on rock and roll.” The band was from San Francisco, after all, and they should know. But thinking about this area’s significant seismic activity, I started to wonder what all these buildings were really sitting on, if not solid ground.
The trivial answer, of course, is that the ground is made up of landfill. By itself, that’s nothing unusual—especially around here. Since the mid-1800s, the San Francisco Bay as a whole has lost 40% of its area to landfill. But in the northeast corner of San Francisco, the large, semicircular slice of land that was once called Yerba Buena Cove has a rather unusual makeup: it’s composed partly of the remains of hundreds of old ships. [Article Continues…]