2003). The combination of these two circumstances leaves the country in a state of increasing seismic risk. Although the hazard remains the same, the rapid expansion of the built environment nationwide—built without proper regard for earthquake potential—is causing the risk to grow steadily. With the exception of the West Coast, most states with seismic vulnerability do not have adequate building codes or policies requiring seismic design; no state in the nation has an adequate program for mitigating the expected unacceptable performance of existing buildings.

To significantly diminish the growth of seismic risk, radical advances are needed that provide a refined understanding of earthquake hazards, and new analysis and design techniques are needed that more accurately accommodate expected ground motions. Current assessment and design procedures are based on simulation studies, laboratory tests, and post-earthquake field observations that result in generalized and conservative procedures for controlling damage. In recent earthquakes, comparison of building damage with ground motion recordings indicates that buildings have generally performed better than anticipated (Heinz and Poland, 2001). Accordingly, it is reasonable to expect that new techniques can be developed that will reduce seismic design requirements and thereby reduce the cost of seismic safety to more affordable levels. Seismic monitoring records hold the key to understanding how the built environment responds to damaging earthquakes and how best to fine-tune the design process so that the need is adequately—but not excessively—met. Monitoring alone is not sufficient to achieve this goal, but it is certainly a necessary component.

The relatively modest funding required for significantly improving seismic monitoring and the subsequent development of new seismic mitigation techniques should be viewed in light of the potential for reducing the cost of constructing new facilities, strengthening existing structures to achieve proper performance, and avoiding losses after major damaging events. The roughly $200 million investment required for improved seismic monitoring and the cost of continuing research using the records should be viewed in light of the more than $800 billion invested annually in construction, the $17.5 trillion value of the built environment in the United States (FEMA, 2004), and the expected $100 billion plus loss from a single, major earthquake in an urban environment (EERI, 2003).

SEISMIC MONITORING AND THE DEVELOPMENT OF EARTHQUAKE ENGINEERING

Earthquake engineering—the application of science and technology to the design, rehabilitation, and repair of the built environment—has developed over the past hundred years as property owners experienced



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