Provides background information and educational materials to help state officials promote the adoption and enforcement of state and local model building codes that contain the latest seismic provisions. These codes can reduce the damage that will occur when future earthquakes strike at-risk parts of the country. It is intended for state earthquake program managers and hazard mitigation officers in the emergency management agencies of the states and territories prone to earthquakes. It is designed to help you convince your state and local governments that codes are effective, inexpensive, and a good investment for the future of our communities. Illustrated.
Recent earthquakes around the world show a pattern of steadily increasing damages and losses that are due primarily to two factors: (1) significant growth in earthquake-prone urban areas and (2) vulnerability of the older building stock, including buildings constructed within the past 20 years. In the United States, earthquake risk has grown substantially with development while the earthquake hazard has remained relatively constant. Understanding the hazard requires studying earthquake characteristics and locales in which they occur while understanding the risk requires an assessment of the potential damage to the built environment and to the welfare of people - especially in high risk areas. Estimating the varying degree of earthquake risk throughout the United States is useful for informed decision-making on mitigation policies, priorities, strategies, and funding levels in the public and private sectors. For example, potential losses to new buildings may be reduced by applying seismic design codes and using specialized construction techniques. However, decisions to spend money on either of those solutions require evidence of risk. In the absence of a nationally accepted criterion and methodology for comparing seismic risk across regions, a consensus on optimal mitigation approaches has been difficult to reach. While there is a good understanding of high risk areas such as Los Angeles, there is also growing recognition that other regions such as New York City and Boston have a low earthquake hazard but are still at high risk of significant damage and loss. This high risk level reflects the dense concentrations of buildings and infrastructure in these areas constructed without the benefit of modern seismic design provisions. In addition, mitigation policies and practices may not have been adopted because the earthquake risk was not clearly demonstrated and the value of using mitigation measures in reducing that risk may not have been understood. This study highlights the impacts of both high risk and high exposure on losses caused by earthquakes. It is based on loss estimates generated by HAZUS(R)-MH, a geographic information system (GIS)-based earthquake loss estimation tool developed by the Federal Emergency Management Agency (FEMA) in cooperation with the National Institute of Building Sciences (NIBS). The HAZUS tool provides a method for quantifying future earthquake losses. It is national in scope, uniform in application, and comprehensive in its coverage of the built environment.
The Rapid Visual Screening (RVS) handbook can be used by trained personnel to identify, inventory, and screen buildings that are potentially seismically vulnerable. The RVS procedure comprises a method and several forms that help users to quickly identify, inventory, and score buildings according to their risk of collapse if hit by major earthquakes. The RVS handbook describes how to identify the structural type and key weakness characteristics, how to complete the screening forms, and how to manage a successful RVS program.
The United States will certainly be subject to damaging earthquakes in the future. Some of these earthquakes will occur in highly populated and vulnerable areas. Coping with moderate earthquakes is not a reliable indicator of preparedness for a major earthquake in a populated area. The recent, disastrous, magnitude-9 earthquake that struck northern Japan demonstrates the threat that earthquakes pose. Moreover, the cascading nature of impacts-the earthquake causing a tsunami, cutting electrical power supplies, and stopping the pumps needed to cool nuclear reactors-demonstrates the potential complexity of an earthquake disaster. Such compound disasters can strike any earthquake-prone populated area. National Earthquake Resilience presents a roadmap for increasing our national resilience to earthquakes. The National Earthquake Hazards Reduction Program (NEHRP) is the multi-agency program mandated by Congress to undertake activities to reduce the effects of future earthquakes in the United States. The National Institute of Standards and Technology (NIST)-the lead NEHRP agency-commissioned the National Research Council (NRC) to develop a roadmap for earthquake hazard and risk reduction in the United States that would be based on the goals and objectives for achieving national earthquake resilience described in the 2008 NEHRP Strategic Plan. National Earthquake Resilience does this by assessing the activities and costs that would be required for the nation to achieve earthquake resilience in 20 years. National Earthquake Resilience interprets resilience broadly to incorporate engineering/science (physical), social/economic (behavioral), and institutional (governing) dimensions. Resilience encompasses both pre-disaster preparedness activities and post-disaster response. In combination, these will enhance the robustness of communities in all earthquake-vulnerable regions of our nation so that they can function adequately following damaging earthquakes. While National Earthquake Resilience is written primarily for the NEHRP, it also speaks to a broader audience of policy makers, earth scientists, and emergency managers.
