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34 Nearly a third of the population of Agadir, Morocco, perished when a nearby earthquake (magnitude 5.7) collapsed many of the city's structures in February 1960, killing 12,000. At top, an apartment building before the quake. At bottom, the same site after the event. ~ ~ z ~ ~ o I W " ~ o w " cal activities in a community. Achieving these goals requires that the extent of the earthquake risks and the exposure of citizens first be identified. This task can take the form of preparing earthquake risk maps, which plot the probability of experiencing a specific level of ground motion within a specific time. Determin- ing the exposure of citizens relies on evaluating the safety of existing structures, water and sewer systems, gas and oil pipelines, and other lifelines. However, determining structure safety is often handicapped by an inability to assess materials and designs used in older construction. Even with the best determination of building properties and conditions, the level of damage a specific ground motion may cause still cannot be predicted accurately. Nonetheless, a number of techniques can be used to strengthen existing structures, and many buildings have been retrofit- ted for increased seismic resistance. As research further develops these techniques and their cost falls, more buildings can be upgraded. What needs to be done during the Decade? First, programs must be initiated that include avoidance, through zoning, of construction on vulnerable sites as well as evaluation and recon- struction after a hazard occurs. In addition, emergency response for buildings and lifelines must be planned and care taken to ensure that these plans are properly implemented, Second, instrumentation networks must be established to determine ground motion influ- ences caused by local site conditions. Such net- works will also provide the means to determine the relationship between specific ground motions and the degree of damage to man-made structures - from initial damage to ultimate collapse. Third, a testing program must be undertaken to explore this relationship between ground motions and the behavior of man-made structures up to the point of collapse, and to develop economical methods to improve the safety of existing build- Ings. Further, efforts must be made to sustain a reasonable level of earthquake preparedness in the minds of citizens. This need includes a continued readiness to respond to earthquake warnings despite the long periods between de- structive quakes and the uncertainties of most warnIngs. Potential projects during the IDNHR include: