A bottle that survived two earthquakes?

The Marina District at the shore of the San Francisco Bay is well known for its strong earthquake site effects. Here, a valley in the bedrock is overlain by thick Pleistocene and Holocene deposits, along with a variety of artificial fills mainly dating from the 1850s to 1920. Both the 1906 San Francisco earthquake and the 1989 Loma Prieta earthquake caused severe damage to structures and lifelines in the district, enhanced by strong site effects. During repair work after the 1989 earthquake, an intact glass bottle was saved from one of the excavation pits. Detailed examination and description of the bottle shows that it is a mouth-blown crown cap soda bottle. Although precise dating of the bottle to the year is not certain, it appears to be possible that the bottle was among some debris from the 1906 earthquake dumped in the area of today's Beach Street.