b. Landslide/mudslide. Museums located on marine or flood plain sediments and/or fill in earthquake zones ‑ are at high risk of foundation failure and landslide/mudslide damage. Sediments with high water content become extremely unstable when disturbed by events such as earthquakes. The major destruction during the 1989 San Francisco earthquake was in the Marina District, an area built on fill over marine sediments. The Turnagain Heights area of Anchorage, Alaska was hit by a 1964 earthquake that generated landslides on raised marine beaches. During the 1989 Loma Prieta earthquake the USS Pampanito pier and adjacent building built on piles driven to bedrock suffered no damage, but the floor of the building (partially built on landfill) collapsed and split open. It was declared unsafe and the submarine was closed to the public for two months. The museum store, artifact storage, and library all had to be moved.
Potential regions of concern: Any high‑risk seismic area with structures built over marine sediments and/or fill such as the National Maritime Museum at San Francisco, or landslide hazardous areas. The late director of the National Center for Earthquake Engineering Research, Robert L. Ketter, predicted that a catastrophic quake will strike east of the Rocky Mountains by the year 2000.
7. Ice and snow. Unprotected small craft and/or structurally unsound sheds may collapse under heavy, wet snow. The yacht America suffered this unfortunate fate. Ice can pull loose caulking from the seams of vessels or create pressure that opens seams, resulting in leaks or even sinking. Heavy ice may prevent the vessel from being moved to lifts for repair.
Potential regions of concern: Any area where ice may occur, but especially marginal areas like the Chesapeake Bay, where ice is so infrequent that when it occurs, few know how to deal with it.