07/22/91

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International conference to discuss earthquake zoning

STANFORD -- Scientists, engineers, and urban planners from around the world will gather on the Stanford campus Aug. 25 to 30 to work on cutting the death toll and economic costs of the globe's worst natural hazard -- earthquakes.

The Fourth International Conference on Seismic Zonation and a related United Nations-sponsored forum will critically review the state of the art in seismic zoning -- the practice of using research from a wide range of technical fields to delineate seismic hazard zones on geographical maps. The information is then used by land use and emergency response planners, architects, construction engineers, property insurers and others.

An example is the new micro-zoning program under development due to California's 1990 Seismic Hazards Mapping Act. The state program will be discussed throughout the conference, and California officials responsible for implementing the law will discuss it in detail at the U.N. forum on Friday, Aug. 30. The goal is to map ground shaking and ground failure throughout the state in order to allow local governments to identify "special study zones." This could guide future land development and reconstruction as well as the way insurance rates are set.

The forum is part of the United Nations' "International Decade for Natural Disaster Reduction." Conference participants will discuss how they might apply the California plan to their own regions or countries.

Reasons for the conference

Five recent earthquakes have underscored the potential for reducing life and property loss with more precise seismic hazard mapping, said Roger Borcherdt, a research engineering seismologist at the United States Geological Survey and co-chair of the conference.

Earthquakes in Mexico City in 1985, the San Francisco Bay Area in 1989, Armenia and Australia in 1989 and the Philippines in 1990 have left virtually no doubt that earthquake damage is highly localized and dependent upon many factors. Subsurface soil conditions, for instance, can have as much to do with damage to a particular building, bridge, or sewer as the structure's distance from a mapped fault line or the earthquake's epicenter, he said.

"Today, we know why earthquake damage occurs in one area of a city and not another. If we can get that information to cities and other governments, they can better decide where to put a playground and where to put a hospital," said Haresh Shah, head of Stanford's civil engineering department and the other co-chair of the conference.

Seismic zoning that takes into account more of the relevant factors would make clear to the public "why buildings in San Francisco's lower Market Street collapsed in 1906 and similar buildings on Telegraph Hill had only cracked chimneys," Borcherdt said. Such zoning could delineate differences at the scale of a few city blocks.

There is also a growing public awareness of the potential for devastating earthquakes in areas where earthquake considerations have not been a significant concern in setting local building standards, Shah said. These include portions of five midwestern states in the "New Madrid" seismic zone, the Northeast from New York north, and the Charleston, S. C., area.

During the 1990s, the U.N. and individual countries are putting substantial resources into reducing earthquake risks as part of the International Decade for Natural Hazard Reduction. Earthquakes kill more people worldwide than any other natural disaster, Shah said.

The conference is sponsored by the Earthquake Engineering Research Institute of Oakland, Calif., in support of the hazard reduction decade. It is funded by the National Science Foundation, with contributions from the Federal Emergency Management Agency, the United States Geological Survey, the Electric Power Research Institute and the National Institute of Standards and Technology. Stanford University is one of the co- sponsors. The Friday forum is funded by the United Nations Educational, Scientific and Cultural Organization and the U.S. Geological Survey.

Conference structure, schedule

Conference planners have structured it to provide overviews of a particular day's topic in the morning and a summary panel discussion at the end of each day. Each day begins with a "state of the art" summary of recent advances in the field and each includes case studies of what has been learned about seismic zoning from recent major earthquakes around the world.

The conference will open Monday, Aug. 26 with a keynote address from Walter R. Lynn, chair of the U.S. National Committee for the International Decade for Natural Disaster Reduction and dean of the faculty at Cornell University.

The state of the art in earth science research that relates to seismic hazard zoning will be the focus of Monday's speeches and discussions.

The state of the art in engineering and construction for seismic safety is the primary topic for Tuesday, Aug. 27.

George Shultz, former U. S. secretary of state and a professor at Stanford's Graduate School of Business, will speak at the luncheon Tuesday at noon.

Socio-economic research including urban planning, public policy and private sector insurance considerations will be the focus of sessions on Wednesday, Aug. 28.

Advances in computer based mapping, expert systems and database technologies -- known collectively as geographic information systems -- will be the primary subject on Thursday, Aug. 29. Technical consultants, government agencies and the insurance industry are using this technology to develop more sophisticated seismic modeling and hazard maps. Vendors will display and demonstrate products throughout the conference, Borcherdt said.

Research papers specific to many regions of the world will be presented orally throughout the conference. Subjects of in- depth case studies include southern Italy and France; eastern Europe; Algeria; Mexico, Chile, and Peru; Japan and China.

Areas covered in North America include California, the Pacific Northwest, the East Coast, and the "new Madrid" area of the Midwest. Research related to California -- especially the 1989 Loma Prieta earthquake of the San Francisco Bay Area, seismic planning in the Los Angeles region, and the state's new zoning program -- are especially well covered in the papers to be presented.

For more information on specific topics and geographical areas, see the preliminary schedule accompanying this release.

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