Sometimes the changes we can deduce are simple. In geology, not always so. If you visit Jack London Square, you shouldn’t miss Heinold’s First and Last Chance Saloon:
The building and its floor are canted, and there’s a step down as you enter. The tilt adds a certain funhouse spice to the smoke-dimmed fixtures and memorabilia. What happened here is that the bar was set on landfill, the kind of early landfill done by Oakland’s first developers using harbor dredgings and other waste. Horse and hands and probably some steam powered the work, and little of that hard effort could be wasted on tamping the muck down to be worthy of the ages. So, imperfectly compacted, the “made land” settled for many years. At the same time, layer after layer of new material was laid around the tipsy little landmark, and now it’s the sunken treasure we enjoy today.
Did the building sink or the land rise? Yes.
Parts of San Francisco have gone through the same history, well south of Market around 10th Street. Old sinking marshland, topped with layer after layer of fill added to keep the streets draining properly, have left century-old homes almost half a story below street grade.
On the California coast, much of the land is gradually rising while, over geologic time, the sea rises and falls. The dance of land and sea sometimes enables the sea to cut deeply into the coast, creating wave-cut platforms that perch above the beaches today. In Oakland that sort of topography is either obscured or nonexistent, most likely because the bay shore has never been exposed to Pacific surf.