Earthquakes can damage collections in many ways. Books may be tossed from shelving and papers from file cabinets. Collections may be scattered, crushed or soiled. Roofs, rooms and buildings may collapse, burying collections under furniture, beams, dirt and yard debris, or leaving collections exposed and vulnerable to wind, rain and snow. Structural collapse may cause fire damage to collections due to broken gas and power lines, as well as water damage from fire hoses and sprinklers, or broken water or sewer pipes. Collections may be recovered from fire and water damage if appropriate measures are taken. Dry collections may be salvaged and cleaned of soil, wet collections may be frozen to prevent mold growth, and broken book bindings, photographs and papers can be boxed or treated by professional conservators. In general, resources for salvage and recovery after floods apply.
What Damage do Earthquakes cause to Libraries and Archives?
Earthquakes may cause total structural collapse leading to the death of staff and researchers or destroyed, damaged or buried collections items. Structural collapse may cause fires due to broken gas lines, as well as water damage to collections from broken pipes, and sewer, fuel, and power lines.
Even if the repository building largely survives intact, earthquakes may toss collections items from shelving; bury collections items under furniture or rubble; damage roofs and walls leaving collection items exposed to the elements; or drown repository collections in mudslides, flooding, or under refuse from the landscape (i.e., downed trees or parts of nearby buildings). Earthquakes also may cause libraries and archives a major loss of original order for archival and special collections and a loss of shelf order and potential damage to descriptive systems if the systems are not backed-up appropriately. Repository staff need to know what their risk level is from earthquakes and plan appropriately.
What Determines the Level of Damage Caused by an Earthquake? Generally the level of damage an earthquake causes to a Library, Archives, or Museums depends upon the earthquake duration and magnitude, your repository’s distance from the epicenter of the quake, as well as:
- Earthquake Frequency: Based on long-term records of the U.S. Geological Survey (USGS), scientists expect about 18 major earthquakes (7.0 magnitude or greater) and one great earthquake (8.0 or greater magnitude) annually worldwide.
- Earthquake Likelihood: FEMA experts estimate that 39 out of 50 states in the U.S. are at risk of an earthquake. Your likelihood of an earthquake varies by location. Some areas are more seismically active such as Alaska and California. Be aware of your repository’s location in relationship to tectonic plate fault and fold lines in your area, which may be located via the USGS Earthquake Hazards Program. In many areas experts have predicted the actual size and impact area of future earthquakes.
- Soil Amplification of Quakes: The thicker and looser the soil on which your structure rests, the more amplified the earthquake effect will be.
- Building Type: If your collections are housed on unreinforced shelving in an unreinforced structure in an earthquake zone, you are at high risk.
- Preparedness: Vulnerability of collections is also dependent on what steps you have taken to mitigate risk, such as placing restraining bars or cords on shelving and ensuring the shelving is appropriately bolted together to stable building elements.
- Trained Staff and Exercised Plans: The level of risk your repository experiences may be somewhat mitigated by having a trained and experienced emergency response staff with a well exercised plan that they are comfortable carrying out.
For information on Emergency Plans, see the following Web sites:
- Federal Emergency Management Website on earthquakes and publications
- USGS Earthquake Hazards Program
- Los Angeles Fire Department Earthquake Preparedness Manual [PDF: 1.9 MB / 40p.]
- Center for Disease Control Earthquakes Emergency Preparedness and Response
- Museum SOS: Preparedness and Mitigation, Structural Mitigation
How do you prevent earthquake damage to your repository? When building or renovating your repository, avoid building near geological fault lines, major rivers and flood zones, volcanoes, sites with poor soil, and related risk factors. If this is impossible, work with a professionally trained and experienced structural engineer to modify your building to withstand an earthquake. Details may be found on how Structural Engineers protect buildings at FEMA's website:
- Techniques for the Seismic Rehabilitation of Existing Buildings
- Designing for Earthquakes: A Manual for Architects
How to make your structure earthquake resistant: For masonry structures, bolt roofs to walls and walls to foundations using steel brackets. Re-point mortar as necessary. For other structures add sheeting to roofs and floors and steel braces, frames and brackets throughout. Reinforce walls, beams, chimneys, and damaged mortar. Securely install track-type lighting. Reinforce building openings, such as crawl spaces, doors, and windows by placing steel frames around them or steel beams in them. Avoid excessive floor loading until structural integrity and floor loading capacity can be determined.
Control Site Risks: Control site-related risks by first identifying them then taking necessary action. For example, review risks from surrounding structures or trees, cutting down dead limbs and placing guy wires on nearby trees or buildings as necessary.
Control Storage Space Risks: When planning your space, select steel shelving with welded frames and cross-braces but without tightly sealed and enclosed air pockets that may promote floating during a flood. Constantly keep all aisles, walkways, and doorways clear. Bolt shelving, filing cabinets, map cases, and major furniture to solid structural components, such as walls, ceilings, and floors, far from doors, escape routes, and computers.
Padding shelving with polyethylene foam sheets limits kinetic damage, but may require approval of your fire marshal. Consider placing small loose items in gasketed and padded cabinets, map cases, or boxes. Store fragile items, such as glass plates, within padded boxes on well-braced shelves. Use restraining bars or cords and similar devices to prevent materials from falling off shelves. Bolt furniture to stable building elements.
Protect Collections from Glass: Ideally avoid storing images or certificates in glass-covered frames; instead store the pieces flat in solandar boxes. If you decide not to remove artwork from frames, use steel S-hooks or double-end bolt snaps to secure framed objects at their top and bottom to storage screens. Replace standard glass exhibit cases and shelving with tempered glass or Plexiglas. Slip a wooden rod into the handles of filing cabinets to ensure that they are held closed. Purchase Velcro type tie-downs for computers. Using mirrors as decorative building elements is not a good idea in earthquake prone areas.
Earthquake Survival: Stay out of rooms with wide span roofs, such as library or archival storage spaces, instead going to small interior windowless rooms without a lot of furniture or loose materials or going outside far from structures or trees. If inside, get under a heavy piece of furniture, such as a desk. Duck, cover your head, and stay curled up until the shaking is over. Stay away from windows, overhead fixtures, bookcases, filing cabinets, loose tools, and electrical equipment. Prepare for aftershocks.
Before evacuating, inspect the evacuation route and staging area to ensure that they are safe and not in a state of collapse. Stay out of elevators, but listen for trapped individuals. Once the earthquake has stopped, evacuate cautiously using the stairs or a door or window. Don’t use matches, candles, or lighters for illumination as gas pipes may be broken; use flashlights. Move cautiously, being prepared for additional shocks and structural instability. Stay away from glass windows, doors, exhibit areas, overhead lighting fixtures, and bookcases as you evacuate. Avoid tall, heavy, and unsecured furniture. Try to determine if everyone has safely evacuated. Notify authorities of missing or trapped individuals and their likely location. Call authorities once you are safely away from the building.